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Sample records for hemlock tsuga heterophylla

  1. The concurrent kinetics of N uptake by soil microbes and western hemlock (Tsuga heterophylla) seedlings: a microcosm study

    NASA Astrophysics Data System (ADS)

    Grenon, Frank; Bradley, Robert; Titus, Brian

    2014-05-01

    There is disagreement over the relative ability of microbes and plants to compete for soil N. Empirical data are needed, therefore, to develop models that can be applied for specific plant species across different soil conditions. We grew western hemlock (Tsuga heterophylla (Raf.) Sarg) seedlings in humus collected from old-growth forest plots (high available C) and from adjacent clearcut plots (low available C). We injected the rhizospheres with either 15N-labelled NH4+ or 15N-labelled amino acid solutions, over a wide range of N concentrations. The uptake of these N compounds by soil microbes and seedlings was assessed 4 h after injection. Microbial uptake rates of NH4+-N were best described by a linear models, whereas microbial uptake of amino acid-N as well as seedling N uptake were best described by asymptotic models. Microbial uptake rates were several orders of magnitude greater than seedling uptake rates, except at low concentrations that are typical under field situations. The provenance of the humus also had significant effects on N uptake kinetics by microbes and seedlings, which were consistent with the available C status of each humus type. Results suggest that differences in N uptake kinetics between plants and microbes are complementary functions that may confer resistance and resilience to forest ecosystems.

  2. Potential feeding deterrents found in hemlock woolly adelgid, Adelges tsugae

    NASA Astrophysics Data System (ADS)

    Jones, Anne C.; Mullins, Donald E.; Jones, Tappey H.; Salom, Scott M.

    2012-07-01

    The nonnative hemlock woolly adelgid ( Adelges tsugae Annand, Hemiptera: Sternorrhyncha: Adelgidae) has been a significant mortality agent of eastern hemlock ( Tsuga canadensis Carriere) throughout a large portion of its geographic range. During a study investigating adelgid vigor in relation to host health, it was noted that adelgid extracts ranged from a yellow to a deep red color. Analysis by GC-MS identified the presence of the anthraquinone, chrysophanol and its anthrone precursor, chrysarobin in the extract. These compounds are predator deterrents in several other insects, including chrysomelid beetles. It is hypothesized that these compounds serve a similar purpose in the hemlock woolly adelgid.

  3. Evaluation of Hemlock (Tsuga)Species and Hybrids for Resistance to Adelges tsugae (Hemiptera:Adelgidae) Using Artificial Infestation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hemlock species and hybrids were evaluated for resistance to the hemlock woolly adelgid, Adelges tsugae Annand. The adelgid was accidentally introduced from Asia to the eastern United States, where it is causing widespread mortality of native hemlocks, Tsuga canadensis and T. caroliniana. The two na...

  4. TSUGA CHINENSIS AS A SOURCE OF HOST RESISTANCE TO THE HEMLOCK WOOLLY ADELGID

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The native eastern hemlock, Tsuga canadensis, and the Carolina hemlock, T. caroliniana, suffer injury and death following infestation by the hemlock woolly adelgid(HWA), Adelges tsugae, an introduced pest. Asian hemlocks are reported to be more tolerant. Research on the nature of genetic resistance ...

  5. Maximizing Oviposition Efficiency when Mass Rearing the Coccinellid, Sasajiscymnus tsugae, a Predator of the Hemlock Woolly Adelgid, Adelges tsugae

    PubMed Central

    Conway, Hugh E.; Culin, Joseph D.; Burgess, LayLa W.; Allard, Cora

    2010-01-01

    Sasajiscymnus tsugae Sasaji and McClure (Coleeptera: Coccinellidae), is a biological control agent imported for management of hemlock woolly adelgid, Adelges tsugae Annand. In mass rearing S. tsugae, accurate estimation of egg numbers is important because larvae are cannibalistic, especially at higher densities. To determine the most accurate means of estimating egg production, three brands of gauze were compared as oviposition substrates. Curad® gauze provided the most accurate estimate of egg production, and was the most cost effective brand. When eggs were collected from oviposition jars, similar adult yields of S. tsugae occurred between rearing cages infested with 1,650 eggs from gauze compared to eggs on the twigs from within these jars. Additionally, orientation of oviposition jars impacted S. tsugae egg production as significantly more eggs were produced in horizontally oriented oviposition jars. PMID:21070172

  6. Development of a Rain Down Technique to Artificially Infest Hemlocks with the Hemlock Woolly Adelgid, Adelges tsugae

    PubMed Central

    Jetton, Robert M.; Mayfield, Albert E.; Powers, Zaidee L.

    2014-01-01

    The hemlock woolly adelgid Adelges tsugae Annand (Hemiptera: Adelgidae), is a non-native invasive pest that has caused widespread decline and mortality of eastern hemlock (Tsuga canadensis (L.) Carr. (Pinales: Pinaceae)) and Carolina hemlock (T. caroliniana Engelm.) in the eastern United States. Our preliminary experiments evaluated the utility of a rain-down technique to induce artificial infestations of A. tsugae on hemlock seedlings en masse. Experiments were conducted in PVC (1 m3) cages topped with poultry wire for placement of A. tsugae-infested branches, and with 1 m2 gridded glue sheets and/or hemlock seedlings placed below to capture adelgid abundance, distribution, and infestation rate data. In the March 2011 experiment, the density of progrediens crawlers (adelgid nymphs, first instars) that rained down inside the PVC cages was significantly higher in the high ovisac treatment compared to the low ovisac treatment, with an estimated 513,000 and 289,000 crawlers per m2 falling beneath each treatment, respectively. Resulting A. tsugae infestation rates on Carolina hemlock seedlings placed inside the cages did not differ between the treatments but were at or above established damage threshold densities for the adelgid. Infestation rates on eastern hemlock seedlings that were placed in cages nine days after the experiment started were below damage threshold levels and did not differ between the treatments. In the May 2011 experiment, the density of sistens crawlers raining down was substantially lower, with 17,000 and 33,000 falling per m2 in the low and high ovisac treatments, respectively. Resulting infestation rates on Carolina hemlock seedlings were extremely low and well below damage threshold levels. Although A. tsugae crawlers were well distributed across the 1 m2 gridded glue sheets placed at the bottom of each cage, hot spots of unusually high crawler density did occur in both experiments. This rain-down technique shows potential for use in an operational tree-breeding program where screening large numbers of hemlock seedlings for resistance to A. tsugae is required. PMID:25199530

  7. Development of a rain down technique to artificially infest hemlocks with the hemlock woolly adelgid, Adelges tsugae.

    PubMed

    Jetton, Robert M; Mayfield, Albert E; Powers, Zaidee L

    2014-01-01

    The hemlock woolly adelgid Adelges tsugae Annand (Hemiptera: Adelgidae), is a non-native invasive pest that has caused widespread decline and mortality of eastern hemlock (Tsuga canadensis (L.) Carr. (Pinales: Pinaceae)) and Carolina hemlock (T. caroliniana Engelm.) in the eastern United States. Our preliminary experiments evaluated the utility of a rain-down technique to induce artificial infestations of A. tsugae on hemlock seedlings en masse. Experiments were conducted in PVC (1 m(3)) cages topped with poultry wire for placement of A. tsugae-infested branches, and with 1 m(2) gridded glue sheets and/or hemlock seedlings placed below to capture adelgid abundance, distribution, and infestation rate data. In the March 2011 experiment, the density of progrediens crawlers (adelgid nymphs, first instars) that rained down inside the PVC cages was significantly higher in the high ovisac treatment compared to the low ovisac treatment, with an estimated 513,000 and 289,000 crawlers per m(2) falling beneath each treatment, respectively. Resulting A. tsugae infestation rates on Carolina hemlock seedlings placed inside the cages did not differ between the treatments but were at or above established damage threshold densities for the adelgid. Infestation rates on eastern hemlock seedlings that were placed in cages nine days after the experiment started were below damage threshold levels and did not differ between the treatments. In the May 2011 experiment, the density of sistens crawlers raining down was substantially lower, with 17,000 and 33,000 falling per m(2) in the low and high ovisac treatments, respectively. Resulting infestation rates on Carolina hemlock seedlings were extremely low and well below damage threshold levels. Although A. tsugae crawlers were well distributed across the 1 m(2) gridded glue sheets placed at the bottom of each cage, hot spots of unusually high crawler density did occur in both experiments. This rain-down technique shows potential for use in an operational tree-breeding program where screening large numbers of hemlock seedlings for resistance to A. tsugae is required. PMID:25373232

  8. Development of a rain down technique to artificially infest hemlocks with the hemlock woolly adelgid, Adelges tsugae.

    PubMed

    Jetton, Robert M; Mayfield, Albert E; Powers, Zaidee L

    2014-01-01

    The hemlock woolly adelgid Adelges tsugae Annand (Hemiptera: Adelgidae), is a non-native invasive pest that has caused widespread decline and mortality of eastern hemlock (Tsuga canadensis (L.) Carr. (Pinales: Pinaceae)) and Carolina hemlock (T. caroliniana Engelm.) in the eastern United States. Our preliminary experiments evaluated the utility of a rain-down technique to induce artificial infestations of A. tsugae on hemlock seedlings en masse. Experiments were conducted in PVC (1 m3) cages topped with poultry wire for placement of A. tsugae-infested branches, and with 1 m(2) gridded glue sheets and/or hemlock seedlings placed below to capture adelgid abundance, distribution, and infestation rate data. In the March 2011 experiment, the density of progrediens crawlers (adelgid nymphs, first instars) that rained down inside the PVC cages was significantly higher in the high ovisac treatment compared to the low ovisac treatment, with an estimated 513,000 and 289,000 crawlers per m(2) falling beneath each treatment, respectively. Resulting A. tsugae infestation rates on Carolina hemlock seedlings placed inside the cages did not differ between the treatments but were at or above established damage threshold densities for the adelgid. Infestation rates on eastern hemlock seedlings that were placed in cages nine days after the experiment started were below damage threshold levels and did not differ between the treatments. In the May 2011 experiment, the density of sistens crawlers raining down was substantially lower, with 17,000 and 33,000 falling per m(2) in the low and high ovisac treatments, respectively. Resulting infestation rates on Carolina hemlock seedlings were extremely low and well below damage threshold levels. Although A. tsugae crawlers were well distributed across the 1 m(2) gridded glue sheets placed at the bottom of each cage, hot spots of unusually high crawler density did occur in both experiments. This rain-down technique shows potential for use in an operational tree-breeding program where screening large numbers of hemlock seedlings for resistance to A. tsugae is required. PMID:25199530

  9. Biophysical characteristics of Adelges tsugae feeding sites on six hemlock (Tsuga) species and a hybrid: implications for resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Characteristics of the plant surface significantly affect host-plant selection by phytophagous insects. Surface morphology of six hemlock species (Tsuga spp.) and a hybrid was investigated using low-temperature scanning electron microscopy. Observations focused on trichome presence and placement a...

  10. Fungi associated with the hemlock woolly adelgid, Adelges tsugae, and assessment of entomopathogenic isolates for management.

    PubMed

    Reid, W R; Parker, B L; Gouli, S Y; Skinner, M; Gouli, V V; Teillon, H B

    2010-01-01

    Fungi associated with the hemlock wooly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), were collected throughout the eastern USA and southern China. Twenty fungal genera were identified, as were 79 entomopathogenic isolates, including: Lecanicillium lecanii (Zimmermann) (Hypocreales: Insertae sedis), Isaria farinosa (Holm: Fries.) (Cordycipitaceae), Beauveria bassiana (Balasamo) (Hyphomycetes), and Fusarium spp (Nectriaceae). The remaining fungal genera associated with insect cadavers were similar for both the USA and China collections, although the abundance of Acremonium (Hypocreaceae) was greater in China. The entomopathogenic isolates were assayed for efficacy against Myzus persicae (Sulzer) (Homoptera: Aphididae) and yielded mortality ranging from 3 to 92%. Ten isolates demonstrating the highest efficacy were further assessed for efficacy against field-collected A. tsugae under laboratory conditions. Overall, two B. bassiana, one L. lecanii, and a strain of Metarhizium anisopliae (Metchnikoff) (Hypocreales: Clavicipitaceae), demonstrated significantly higher efficacy against A. tsugae than the others. Isolates were further evaluated for conidial production, germination rate and colony growth at four temperatures representative of field conditions. All isolates were determined to be mesophiles with optimal temperature between 25-30 degrees C. In general, conidial production increased with temperature, though two I. farinosa produced significantly more conidia at cooler temperatures. When efficacy values were compared with conidial production and temperature tolerances, Agricultural Research Service Collection of Entomopathogenic Fungi (ARSEF) 1080, 5170, and 5798 had characteristics comparable to the industrial B. bassiana strain GHA. PMID:20672977

  11. Fungi Associated with the Hemlock Woolly Adelgid, Adelges tsugae, and Assessment of Entomopathogenic Isolates for Management

    PubMed Central

    Reid, W.R.; Parker, B.L.; Gouli, S.Y.; Skinner, M.; Gouli, V.V.; Teillon, H.B.

    2010-01-01

    Fungi associated with the hemlock wooly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), were collected throughout the eastern USA and southern China. Twenty fungal genera were identified, as were 79 entomopathogenic isolates, including: Lecanicillium lecanii (Zimmermann) (Hypocreales: Insertae sedis), Isaria farinosa (Holm: Fries.) (Cordycipitaceae), Beauveria bassiana (Balasamo) (Hyphomycetes), and Fusarium spp (Nectriaceae). The remaining fungal genera associated with insect cadavers were similar for both the USA and China collections, although the abundance of Acremonium (Hypocreaceae) was greater in China. The entomopathogenic isolates were assayed for efficacy against Myzus persicae (Sulzer) (Homoptera: Aphididae) and yielded mortality ranging from 3 to 92%. Ten isolates demonstrating the highest efficacy were further assessed for efficacy against field-collected A. tsugae under laboratory conditions. Overall, two B. bassiana, one L. lecanii, and a strain of Metarhizium anisopliae (Metchnikoff) (Hypocreales: Clavicipitaceae), demonstrated significantly higher efficacy against A. tsugae than the others. Isolates were further evaluated for conidial production, germination rate and colony growth at four temperatures representative of field conditions. All isolates were determined to be mesophiles with optimal temperature between 25–30° C. In general, conidial production increased with temperature, though two I. farinosa produced significantly more conidia at cooler temperatures. When efficacy values were compared with conidial production and temperature tolerances, Agricultural Research Service Collection of Entomopathogenic Fungi (ARSEF) 1080, 5170, and 5798 had characteristics comparable to the industrial B. bassiana strain GHA. PMID:20672977

  12. Carbon exchange of an old-growth eastern hemlock (Tsuga canadensis) forest in central New England.

    PubMed

    Hadley, Julian L; Schedlbauer, Jessica L

    2002-11-01

    Carbon (C) exchange of an approximately 200-year-old eastern hemlock (Tsuga canadensis L.) forest in central Massachusetts, USA, was estimated from mid-October 2000 through October 2001 based on eddy covariance measurements and statistical modeling from microclimatic data. Measurements were made in 68% of the hours during the year of study, with > 50% coverage in all months except December and August. Data were filtered by wind direction and atmospheric turbulence to remove invalid measurements. Analysis of filtered data showed that photosynthetically active radiation (PAR) was significant in predicting C exchange, except during the winter. Daily minimum air temperature affected C exchange in autumn and winter, whereas time of day, water vapor pressure deficit and air temperature had significant effects on C storage in spring, summer and fall. Most C storage in the stand occurred in April through July and in October 2001, with maximum rates in April and May. Persistent cold weather prevented C storage in December through March. In early spring 2001, C uptake was sensitive to nocturnal frost: daily minimum air temperatures below 0 degrees C reduced C fixation, and minima below -5 degrees C caused its virtual cessation. Soil temperature was a poor predictor of C balance during this period. In August, high soil and air temperatures (averaging 16.7 and 21.1 degrees C, respectively) drove high ecosystem respiration, which approximately balanced C uptake. These patterns show potential for stimulated C storage in hemlock forests in a warmer climate with fewer spring and autumn frosts, but reduced C storage during warmer summers. Estimated annual C storage was 3.0 Mg ha(-1), which is higher than for younger coniferous and deciduous forests during earlier years in the northeastern USA. Long-term data are needed to determine if the estimated high C storage in this hemlock forest is a result of interannual climate variation or an effect of forest composition. PMID:12414368

  13. Species richness and abundance of ectomycorrhizal basidiomycete sporocarps on a moisture gradient in the Tsuga heterophylla zone

    USGS Publications Warehouse

    O'Dell, Thomas E.; Ammirati, Joseph F.; Schreiner, Edward G.

    1999-01-01

    Sporocarps of epigeous ectomycorrhizal fungi and vegetation data were collected from eight Tsuga heterophylla (Raf.) Sarg. - Pseudotsuga menziesii (Mirb.) Franco stands along a wet to dry gradient in Olympic National Park, Washington, U.S.A. One hundred and fifty species of ectomycorrhizal fungi were collected from a total sample area of 2.08 ha. Over 2 years, fungal species richness ranged from 19 to 67 taxa per stand. Sporocarp standing crop ranged from 0 to 3.8 kg/ha, averaging 0.58 kg/ha, 0.06 kg/ha in spring and 0.97 kg/ha in fall. Sporocarp standing crop and fungal species richness were correlated with precipitation. These results demonstrated that ectomycorrhizal fungal sporocarp abundance and species richness can be partly explained in terms of an environmental gradient.

  14. Testing the Climate Sensitivity of Mountain Hemlock (Tsuga mertensiana (Bong.) Carr.) Near the Southern Limit of Its Range

    NASA Astrophysics Data System (ADS)

    Appleton, S.; St George, S.

    2014-12-01

    This study investigates the climate sensitivity of mountain hemlock (Tsuga mertensiana (Bong.) Carr.) near the southern limit of its range, tests the stability of its climate-tree relations over the last few decades, and explores its potential as a hydroclimatic proxy for Crater Lake National Park. We collected tree cores at seven locations around the caldera rim, focusing on hemlock growing at higher elevations (2000-2400 masl). The median length of all ring-width series is 283 years, and the oldest hemlock sample extends back to C.E. 1450. Several types of anatomical anomalies, including frost rings, traumatic resin ducts, false rings, and light late-wood bands were observed within the specimens, the most common feature being a false ring in C.E. 1810. Each set of standardized ring-width measurements has a strong common signal, with between-tree correlations (r-bar) ranging from 0.31 to 0.49. Preliminary analysis suggests hemlock growth across the park is strongly and inversely related to total cool-season precipitation, and is also influenced positively (albeit more weakly) by mean summer temperature. Most sites are significantly and negatively correlated with total December-to-February precipitation (r = -0.41) and total precipitation from December to August (r = -0.48). Compared to other ring-width records exhibiting similar negative responses to winter precipitation, these hemlocks appear to track that specific signal quite clearly and, as a result, these data may be suitable to reconstruct past changes in cool-season moisture in Crater Lake National Park and across the broader southern Cascades.

  15. Behavior and Daily Activity Patterns of Specialist and Generalist Predators of the Hemlock Woolly Adelgid, Adelges tsugae

    PubMed Central

    Flowers, R.W.; Salom, S.M.; Kok, L.T.; Mullins, D.E.

    2007-01-01

    The behavior and daily activity patterns of two specialist predators, Laricobius nigrinus Fender (Coleoptera: Derodontidae) and Sasajiscymnus tsugae, Sasaji and McClure (Coleoptera: Coccinellidae), and a generalist predator, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), of hemlock woolly adelgid, Adelges tsugae (Hemiptera: Adelgidae), were examined using digital video recording in the laboratory. The two specialists are part of a biological control program for A. tsugae, and it is not known if competitive interactions with previously established generalist predators will negatively impact their effectiveness. The behavior and daily activity patterns of adult females of each species were documented in single- and paired-predator assays under simulated spring and summer conditions. Behavior varied qualitatively and quantitatively by species, and did not appear to be highly coordinated temporally or spatially. All species exhibited continuous activity patterns that were punctuated by longer periods of rest. Extensive and intensive searching behavior occurred in all species, with intensive searching being highly variable. Specialist predators appeared to be more selective of feeding and oviposition sites, and rested at more concealed locations than the generalist species. In spring conditions, L. nigrinus had greater activity and a more even behavior distribution than S. tsugae or H. axyridis, which were skewed towards resting. In summer, the latter two species showed increased activity at higher temperatures. Conspecifics significantly altered the time allocated to specific behaviors for L. nigrinus and H. axyridis, resulting in reduced predator effectiveness by reducing time and energy expenditure on activities that directly impact the adelgids. In contrast, S. tsugae conspecifics and all heterospecific combinations showed non-interference. The activity of each species varied with time of day; L. nigrinus was more active at night, while S. tsugae and H. axyridis were more active during the day. All predator groupings maintained a high degree of spatial separation relative to assay size. The use of multiple-predator species combinations that include the specialist predators, is recommended over single-species for biological control of A. tsugae, as temporal and spatial patterns were not highly coordinated. Low-density releases may reduce the potential negative effects of intraspecific competition. PMID:20345314

  16. Diversity of proteobacterial endosymbionts in hemlock woolly adelgid (Adelges tsugae) (Hemiptera: Adelgidae) from its native and introduced range.

    PubMed

    von Dohlen, Carol D; Spaulding, Usha; Shields, Kathleen; Havill, Nathan P; Rosa, Cristina; Hoover, Kelli

    2013-07-01

    Knowledge of intraspecific variation in symbioses may aid in understanding the ecology of widespread insects in different parts of their range. We investigated bacterial symbionts of Adelges tsugae, a pest of hemlocks in eastern North America introduced from Asia. Amplification, cloning, and sequencing of bacterial 16S rDNA, in situ hybridizations, and electron microscopy revealed that A. tsugae harbours up to five bacterial phylotypes, according to population. Three Gammaproteobacteria species are maternally transmitted. The first, designated 'Ca. Pseudomonas adelgestsugas' resides in the haemocoel, and was detected in all populations except Taiwan. The second phylotype, 'Ca. Serratia symbiotica', resides in bacteriocytes of populations on Tsuga sieboldii in Japan and in E. North America. The third phylotype, designated 'Ca. Annandia adelgestsuga', clustered within a lineage of several insect endosymbionts that included Buchnera aphidicola. It was detected in bacteriocytes in all populations, and in salivary glands of first instars. Two Betaproteobacteria phylotypes were detected in some Japanese T. sieboldii and eastern North America populations, and were observed only in salivary glands with no evidence of maternal transmission. Our results support the ideas that symbiont gain and loss has been volatile in adelgids, and that symbionts may help to trace the source of invasive species. PMID:23452267

  17. Censusing and modeling the dynamics of a population of eastern hemlock (Tsuga canadensis L.) using remote sensing

    NASA Astrophysics Data System (ADS)

    Lamar, W. Robert

    A population of eastern hemlock (Tsuga canadensis L.) was censused from the ground using traditional field methods and from the air using large scale, high-resolution, aerial imagery in the early spring of 1997, 1998 and 1999. A manual crown survey map of the population, prepared from aerial imagery, was compared to a traditional field census. Over 60% of the individuals measured on the ground were not detected in the aerial census. Tree size, crown density and crown position all played roles in determining a crown's visibility from the air. Nearly all large, upper canopy hemlocks were visible in the aerial census. An important minority of small, lower canopy hemlocks were also visible in the aerial census. An automated spatial segmentation procedure was developed to identify and measure individual population units, or blobs, within the forest population. A blob was defined as a distinct portion of crown segmented from its neighbors on the basis of size, shape, and connectivity. To ensure the comparability of multi-year segmentation maps, an automated blob reconciliation procedure was also developed to make certain that no hemlock pixels were assigned to different blobs in different years. Following spatial segmentation and reconciliation, a large majority of hemlock blobs (˜64--72%) were found to be closely associated with ground referenced, manually delineated, individual hemlock crowns. The remaining blobs consisted of spatially distinct parts of a crown or closely clumped multiple crowns. Matrix population models were constructed from the ground-derived and aerial-derived population data. Matrix analysis produced a number of useful population characteristics including overall population growth rate (lambda), stable stage distributions, reproductive values, and sensitivity values. lambda's calculated from the aerial and ground-derived matrices were compared using randomization tests. While providing a different perspective and description of a population than traditional ground studies, demographic studies using remote sensing provide some promising advantages. The spatially explicit nature of the data permits more biologically realistic modeling of the population and the investigation of potential environmental influences on population dynamics. Automated extraction of demographic or megademographic data from remotely sensed images represents an important first step toward scaling population analysis to the landscape and regional levels.

  18. Ancient and modern colonization of North America by hemlock woolly adelgid, Adelges tsugae (Hemiptera: Adelgidae), an invasive insect from East Asia.

    PubMed

    Havill, Nathan P; Shiyake, Shigehiko; Lamb Galloway, Ashley; Foottit, Robert G; Yu, Guoyue; Paradis, Annie; Elkinton, Joseph; Montgomery, Michael E; Sano, Masakazu; Caccone, Adalgisa

    2016-05-01

    Hemlock woolly adelgid, Adelges tsugae, is an invasive pest of hemlock trees (Tsuga) in eastern North America. We used 14 microsatellites and mitochondrial COI sequences to assess its worldwide genetic structure and reconstruct its colonization history. The resulting information about its life cycle, biogeography and host specialization could help predict invasion by insect herbivores. We identified eight endemic lineages of hemlock adelgids in central China, western China, Ulleung Island (South Korea), western North America, and two each in Taiwan and Japan, with the Japanese lineages specializing on different Tsuga species. Adelgid life cycles varied at local and continental scales with different sexual, obligately asexual and facultatively asexual lineages. Adelgids in western North America exhibited very high microsatellite heterozygosity, which suggests ancient asexuality. The earliest lineages diverged in Asia during Pleistocene glacial periods, as estimated using approximate Bayesian computation. Colonization of western North America was estimated to have occurred prior to the last glacial period by adelgids directly ancestral to those in southern Japan, perhaps carried by birds. The modern invasion from southern Japan to eastern North America caused an extreme genetic bottleneck with just two closely related clones detected throughout the introduced range. Both colonization events to North America involved host shifts to unrelated hemlock species. These results suggest that genetic diversity, host specialization and host phylogeny are not predictive of adelgid invasion. Monitoring non-native sentinel host trees and focusing on invasion pathways might be more effective methods of preventing invasion than making predictions using species traits or evolutionary history. PMID:26880353

  19. Orientation behavior of the predator Laricobius nigrinus (Coleoptera: Derodontidae) to hemlock woolly adelgid and host tree odors in a multi-chambered olfactometer.

    PubMed

    Wallin, Kimberly F; Latty, Tanya M; Ross, Darrell W

    2011-08-01

    We studied the adult ambulatory response of the predator, Laricobius nigrinus Fender (Coleoptera: Derodontidae), to odors from its prey, Adelges tsugae Annand, the hemlock woolly adelgid, and foliage of hemlock woolly adelgid, host hemlocks (Tsuga spp.), and other conifers. Both the predator and hemlock woolly adelgid are apparently native to western North America, but the predator is being released in the eastern United States, which has different hemlock species, for biological control of a lineage of hemlock woolly adelgid inadvertently introduced from Japan. L. nigrinus responded to odors from hemlock woolly adelgid host trees, but not to odors from hemlock woolly adelgid. L. nigrinus collected from hemlock woolly adelgid-infested western hemlock were more strongly attracted to odors from western hemlock [Tsuga heterophylla (Rafinesque) Sargent] than eastern hemlock [Tsuga canadensis (L.) Carrière] in most trials. Odors from western white pine (Pinus monticola Douglas ex D. Don) and white spruce [Picea glauca (Moench) Voss] were as attractive as western hemlock odors whereas odors from Douglas-fir [Pseudotsuga menziesii variety menziesii (Mirbel)] and ponderosa pine (Pinus ponderosa Douglas ex Lawson) were avoided. L. nigrinus reared on hemlock woolly adelgid-infested eastern hemlock in the laboratory were lethargic and were not attracted to either eastern or western hemlock odors. Predators collected in the field and tested monthly from December to March responded similarly each month, except February, when they flew rather than walked in the olfactometer, suggesting a period of dispersal or mate finding at that time of year. The implications of these results for programs to release L. nigrinus in the eastern United States for control of hemlock woolly adelgid are discussed. PMID:22251687

  20. HEMLOCK

    SciTech Connect

    2009-03-25

    HEMLOCK (Heterogeneous Ensemble Machine Learning Open Classification Kit) is a software tool for constructing, evaluating, and applying heterogeneous ensemble data models for use in solving supervised machine learning problems. Specifically, the main class of problems targeted by HEMLOCK is the problem of multiple-class classification (also called labeling or categorization) of data with continuous or discrete features. HEMLOCK consists of various data readers, machine learning algorithms, model combination and comparison routines, evaluation methods for model performance testing, and interfaces to external, state-of-the-art machine learning software libraries.

  1. HEMLOCK

    Energy Science and Technology Software Center (ESTSC)

    2009-03-25

    HEMLOCK (Heterogeneous Ensemble Machine Learning Open Classification Kit) is a software tool for constructing, evaluating, and applying heterogeneous ensemble data models for use in solving supervised machine learning problems. Specifically, the main class of problems targeted by HEMLOCK is the problem of multiple-class classification (also called labeling or categorization) of data with continuous or discrete features. HEMLOCK consists of various data readers, machine learning algorithms, model combination and comparison routines, evaluation methods for model performancemore » testing, and interfaces to external, state-of-the-art machine learning software libraries.« less

  2. Forest expansion and climate change in the Mountain Hemlock (Tsuga mertensiana) zone, Lassen Volcanic National Park, California, U.S.A.

    SciTech Connect

    Taylor, A.H.

    1995-08-01

    The relationship between climate change and the dynamics of ecotonal populations of mountain hemlock (Tsuga mertensiana [Bong.] Carr.) was determined by comparing climate and the age structure of trees from 24 plots and seedlings from 13 plots in the subalpine zone of Lassen Volcanic National Park, California. Tree establishment was greatest during periods with above normal annual and summer temperatures, and normal or above normal precipitation. Seedling establishment was positively correlated with above normal annual and summer temperatures and negatively correlated with April snowpack depth. The different responses of trees and seedlings to precipitation variation is probably related to site soil moisture conditions. Mountain hemlock populations began to expand in 1842 and establishment increased dramatically after 1880 and peaked during a warm mesic period between 1895 and 1910. The onset of forest expansion coincides with warming that began at the end of the Little Ice Age (1850-1880). These data indicate that stability of the mountain hemlock ecotone is strongly influenced by climate. If warming induced by greenhouse gases does occur as climate models predict, then the structure and dynamics of near timberline forests in the Pacific Northwest will change. 52 refs., 8 figs., 3 tabs.

  3. RECOVERY OF EASTERN HEMLOCK FROM ADELGID ATTACK

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technical Abstract: (Same requirements as Interpretive Summary) Hemlock woolly adelgid, Adelges tsugae, is a very serious pest of hemlocks, Tsuga spp., in the eastern United States. Although a variety of insecticides are capable of controlling hemlock woolly adelgid, the systemic insecticide, imida...

  4. Impacts of dwarf mistletoe on the physiology of host Tsuga heterophylla trees as recorded in tree-ring C and O stable isotopes.

    PubMed

    Marias, Danielle E; Meinzer, Frederick C; Woodruff, David R; Shaw, David C; Voelker, Steven L; Brooks, J Renée; Lachenbruch, Barbara; Falk, Kristen; McKay, Jennifer

    2014-06-01

    Dwarf mistletoes, obligate, parasitic plants with diminutive aerial shoots, have long-term effects on host tree water relations, hydraulic architecture and photosynthetic gas exchange and can eventually induce tree death. To investigate the long-term (1886-2010) impacts of dwarf mistletoe on the growth and gas exchange characteristics of host western hemlock, we compared the diameter growth and tree-ring cellulose stable carbon (C) and oxygen (O) isotope ratios (δ(13)Ccell, δ(18)Ocell) of heavily infected and uninfected trees. The relative basal area growth of infected trees was significantly greater than that of uninfected trees in 1886-90, but declined more rapidly in infected than uninfected trees through time and became significantly lower in infected than uninfected trees in 2006-10. Infected trees had significantly lower δ(13)Ccell and δ(18)Ocell than uninfected trees. Differences in δ(18)Ocell between infected and uninfected trees were unexpected given that stomatal conductance and environmental variables that were expected to influence the δ(18)O values of leaf water were similar for both groups. However, estimates of mesophyll conductance (gm) were significantly lower and estimates of effective path length for water movement (L) were significantly higher in leaves of infected trees, consistent with their lower values of δ(18)Ocell. This study reconstructs the long-term physiological responses of western hemlock to dwarf mistletoe infection. The long-term diameter growth and δ(13)Ccell trajectories suggested that infected trees were growing faster than uninfected trees prior to becoming infected and subsequently declined in growth and leaf-level photosynthetic capacity compared with uninfected trees as the dwarf mistletoe infection became severe. This study further points to limitations of the dual-isotope approach for identifying sources of variation in δ(13)Ccell and indicates that changes in leaf internal properties such as gm and L that affect δ(18)Ocell must be considered. PMID:24973917

  5. Failure under stress: the effect of the exotic herbivore Adelges tsugae on biomechanics of Tsuga canadensis

    PubMed Central

    Soltis, Nicole E.; Gomez, Sara; Leisk, Gary G.; Sherwood, Patrick; Preisser, Evan L.; Bonello, Pierluigi; Orians, Colin M.

    2014-01-01

    Background and Aims Exotic herbivores that lack a coevolutionary history with their host plants can benefit from poorly adapted host defences, potentially leading to rapid population growth of the herbivore and severe damage to its plant hosts. The hemlock woolly adelgid (Adelges tsugae) is an exotic hemipteran that feeds on the long-lived conifer eastern hemlock (Tsuga canadensis), causing rapid mortality of infested trees. While the mechanism of this mortality is unknown, evidence indicates that A. tsugae feeding causes a hypersensitive response and alters wood anatomy. This study investigated the effect of A. tsugae feeding on biomechanical properties at different spatial scales: needles, twigs and branches. Methods Uninfested and A. tsugae-infested samples were collected from a common garden experiment as well as from naturally infested urban and rural field sites. Tension and flexure mechanical tests were used to quantify biomechanical properties of the different tissues. In tissues that showed a significant effect of herbivory, the potential contributions of lignin and tissue density on the results were quantified. Key Results Adelges tsugae infestation decreased the abscission strength, but not flexibility, of needles. A. tsugae feeding also decreased mechanical strength and flexibility in currently attacked twigs, but this effect disappeared in older, previously attacked branches. Lignin and twig tissue density contributed to differences in mechanical strength but were not affected by insect treatment. Conclusions Decreased strength and flexibility in twigs, along with decreased needle strength, suggest that infested trees experience resource stress. Altered growth patterns and cell wall chemistry probably contribute to these mechanical effects. Consistent site effects emphasize the role of environmental variation in mechanical traits. The mechanical changes measured here may increase susceptibility to abiotic physical stressors in hemlocks colonized by A. tsugae. Thus, the interaction between herbivore and physical stresses is probably accelerating the decline of eastern hemlock, as HWA continues to expand its range. PMID:24335663

  6. Stem Densities of Trees from Overstocked Mixed Conifer Stands of Western Hemlock, Douglas-fir and Western Redcedar.

    SciTech Connect

    Pong, W.Y.; Waddell, Dale R.; Biomass and Energy Project

    1985-03-15

    This report presents results from a stem density (wood and bark combined) study conducted on trees from overstocked mixed conifer stands of Douglas-fir (Pseudotsuga menziesii), western hemlock (Tsuga heterophylla) and western redcedar (Thuja plicata) located on the Quilcene Ranger District, Olympic National Forest in the State of Washington. Information on the density of stem wood that is available in literature generally have been derived from trees growing in stands of normal stocking levels. Stem densities, an essential parameter in the determination of stem biomass, have not been investigated for trees growing in overstocked conditions. Predictive estimators of density based on data derived from studies of normally stocked stands can not be applied to trees growing in an overstocked condition with any reliability. There is need to specifically examine stem densities in trees grown under these adverse conditions. 3 refs., 3 tabs.

  7. Genetic evaluation of alternative silvicultural systems in coastal montane forests: western hemlock and amabilis fir.

    PubMed

    El-Kassaby, Y A; Dunsworth, B G; Krakowski, J

    2003-08-01

    Genetic diversity and mating system were quantified for shelterwood, patch cut and green tree-retention silvicultural systems, and compared to adjacent old-growth. This is a component of a larger study conducted in montane old-growth forests of coastal British Columbia to evaluate the feasibility and ecological consequences of alternative silvicultural systems. The experiment includes replicated treatments representing a range of overstory removal adjacent to old-growth and clearcut areas. Based on 22 electrophoretically assayed loci, the effects of silvicultural systems on genetic parameters of amabilis fir (Abies amabilis and western hemlock (Tsuga heterophylla were assessed by comparing an average number of alleles per locus, the percent polymorphic loci, and observed and expected heterozygosity between parental populations and naturally regenerated progeny as well as among treatments. Genetic variation in natural regeneration was greater than in parental populations, especially for low-frequency alleles. Silvicultural treatments caused no significant differences in amabilis fir genetic-diversity parameters, while the shelterwood system resulted in lower observed and expected heterozygosity in western hemlock. Nei's genetic distance revealed that all parental populations were extremely similar. The two species had contrasting mating system dynamics with amabilis fir producing higher levels of correlated paternity and inbreeding with wider variation among individual tree outcrossing-rate estimates. Western hemlock had significant levels of correlated paternity only for the green tree and shelterwood treatments demonstrating family structuring inversely related to stand density. Inbreeding in western hemlock was significant but lower than that observed for amabilis fir with a J-shaped distribution for individual tree multilocus outcrossing-rate estimates. The pollination and dispersal mechanisms of the two species represent the most-likely factors causing these differences. Artificial regeneration may be utilized to augment the genetic resources of natural ingress. PMID:12750773

  8. Feeding preference of three lady beetle predators of the hemlock woolly adelgid (Homoptera: Adelgidae).

    PubMed

    Butin, Elizabeth E; Havill, Nathan P; Elkinton, Joseph S; Montgomery, Michael E

    2004-10-01

    In a laboratory study, we tested the feeding preferences of three coccinellid predators of hemlock woolly adelgid, Adelges tsugae Annand, an introduced pest of hemlock in the eastern United States. The species tested were Sasajiscymnus tsugae Sasaji & McClure (formerly Pseudoscymnus tsugae) from Japan, Scymnus ningshanensis Yu & Yao from China, and Harmonia axyridis (Pallas), a generalist species introduced from Asia that is currently widespread in eastern hemlock, Tsuga canadensis Carriere, forests. We measured the feeding preference of each beetle species when given the choice of A. tsugae and either 1) Pineus strobi (Hartig) on Pinus strobus L.; 2) Adelges laricis Vallot on Larix decidua Mill.; 3) Adelges cooleyi (Gillette) on Pseudotsuga menziesii (Mirb.) Franco; or 3) Paraprociphilus tessellatus (Fitch) on Alnus serrulata (Ait.) Willd. We evaluated beetle preference for adults, nymphs, and eggs of each prey species. Generally, when adult or nymphal prey stages were compared, S. tsugae preferred A. tsugae adults to P. strobi, A. cooleyi, A. laricis, and P. tessellatus. S. ningshanensis showed less preference between adelgid species, but it did not prefer P. tessellatus nymphs. When preferences for adelgid eggs were assayed, S. tsugae and S. ningshanensis showed no preference between A. tsugae and A. cooleyi or P. strobi, but S. tsugae did prefer A. tsugae to A. laricis. Larvae of S. tsugae were unable to survive on P. tessellatus nymphs. H. axyridis adults readily consumed both A. tsugae and P. tessellatus, but H. axyridis larvae did not complete their life cycle on A. tsugae. Our host range tests suggest that S. ningshanensis and S. tsugae may feed on several species of Adelgidae and that A. tsugae is often preferred. PMID:15568353

  9. Hemlock woolly adelgid and elongate hemlock scale induce changes in foliar and twig volatiles of eastern hemlock.

    PubMed

    Pezet, Joshua; Elkinton, Joseph; Gomez, Sara; McKenzie, E Alexa; Lavine, Michael; Preisser, Evan

    2013-08-01

    Eastern hemlock (Tsuga canadensis) is in rapid decline because of infestation by the invasive hemlock woolly adelgid (Adelges tsugae; 'HWA') and, to a lesser extent, the invasive elongate hemlock scale (Fiorinia externa; 'EHS'). For many conifers, induced oleoresin-based defenses play a central role in their response to herbivorous insects; however, it is unknown whether eastern hemlock mobilizes these inducible defenses. We conducted a study to determine if feeding by HWA or EHS induced changes in the volatile resin compounds of eastern hemlock. Young trees were experimentally infested for 3 years with HWA, EHS, or neither insect. Twig and needle resin volatiles were identified and quantified by gas chromatography/mass spectrometry. We observed a suite of changes in eastern hemlock's volatile profile markedly different from the largely terpenoid-based defense response of similar conifers. Overall, both insects produced a similar effect: most twig volatiles decreased slightly, while most needle volatiles increased slightly. Only HWA feeding led to elevated levels of methyl salicylate, a signal for systemic acquired resistance in many plants, and benzyl alcohol, a strong antimicrobial and aphid deterrent. Green leaf volatiles, often induced in wounded plants, were increased by both insects, but more strongly by EHS. The array of phytochemical changes we observed may reflect manipulation of the tree's biochemistry by HWA, or simply the absence of functional defenses against piercing-sucking insects due to the lack of evolutionary contact with these species. Our findings verify that HWA and EHS both induce changes in eastern hemlock's resin chemistry, and represent the first important step toward understanding the effects of inducible chemical defenses on hemlock susceptibility to these exotic pests. PMID:23900803

  10. Laboratory Studies of Feeding and Oviposition Preference, Developmental Performance, and Survival of the Predatory Beetle, Sasajiscymnus tsugae on Diets of the Woolly Adelgids, Adelges tsugae and Adelges piceae

    PubMed Central

    Jetton, Robert M.; Monahan, John F.; Hain, Fred P.

    2011-01-01

    The suitability of the balsam woolly adelgid, Adelges piceae Ratzeburg (Hemiptera: Adelgidae) as an alternate mass rearing host for the adelgid predator, Sasajiscymnus tsugae Sasaji and McClure (Coleoptera: Coccinellidae) was studied in the laboratory. This predator is native to Japan and has been introduced to eastern hemlock, Tsuga canadensis (L.) Carrière (Pinales: Pinaceae), forests throughout the eastern United States for biological control of the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), also of Japanese origin. Feeding, oviposition, immature development, and adult long-term survival of S. tsugae were tested in a series of no choice (single-prey) and paired-choice experiments between the primary host prey, A. tsugae, and the alternate host prey, A. piceae. In paired-choice feeding tests, the predator did not discriminate between eggs of the two adelgid species, but in the no choice tests the predator did eat significantly more eggs of A. piceae than those of A. tsugae. S. tsugae accepted both test prey for oviposition and preferred to lay eggs on adelgid infested versus noninfested host plants. Overall oviposition rates were very low (< 1 egg per predator female) in the oviposition preference tests. Predator immature development rates did not differ between the two test prey, but only 60% of S. tsugae survived egg to adult development when fed A. piceae compared to 86% when fed A. tsugae. S. tsugae adult long-term survival was significantly influenced (positively and negatively) by prey type and the availability of a supplemental food source (diluted honey) when offered aestivating A. tsugae sistens nymphs or ovipositing aestivosistens A. piceae adults, but not when offered ovipositing A. tsugae sistens adults. These results suggest that the development of S. tsugae laboratory colonies reared on a diet consisting only of A. piceae may be possible, and that the biological control potential of the predator might be expanded to include management of A. piceae in Christmas tree plantations. PMID:21867435

  11. Laboratory studies of feeding and oviposition preference, developmental performance, and survival of the predatory beetle, Sasajiscymnus tsugae on diets of the woolly adelgids, Adelges tsugae and Adelges piceae.

    PubMed

    Jetton, Robert M; Monahan, John F; Hain, Fred P

    2011-01-01

    The suitability of the balsam woolly adelgid, Adelges piceae Ratzeburg (Hemiptera: Adelgidae) as an alternate mass rearing host for the adelgid predator, Sasajiscymnus tsugae Sasaji and McClure (Coleoptera: Coccinellidae) was studied in the laboratory. This predator is native to Japan and has been introduced to eastern hemlock, Tsuga canadensis (L.) Carrière (Pinales: Pinaceae), forests throughout the eastern United States for biological control of the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), also of Japanese origin. Feeding, oviposition, immature development, and adult long-term survival of S. tsugae were tested in a series of no choice (single-prey) and paired-choice experiments between the primary host prey, A. tsugae, and the alternate host prey, A. piceae. In paired-choice feeding tests, the predator did not discriminate between eggs of the two adelgid species, but in the no choice tests the predator did eat significantly more eggs of A. piceae than those of A. tsugae. S. tsugae accepted both test prey for oviposition and preferred to lay eggs on adelgid infested versus noninfested host plants. Overall oviposition rates were very low (< 1 egg per predator female) in the oviposition preference tests. Predator immature development rates did not differ between the two test prey, but only 60% of S. tsugae survived egg to adult development when fed A. piceae compared to 86% when fed A. tsugae. S. tsugae adult long-term survival was significantly influenced (positively and negatively) by prey type and the availability of a supplemental food source (diluted honey) when offered aestivating A. tsugae sistens nymphs or ovipositing aestivosistens A. piceae adults, but not when offered ovipositing A. tsugae sistens adults. These results suggest that the development of S. tsugae laboratory colonies reared on a diet consisting only of A. piceae may be possible, and that the biological control potential of the predator might be expanded to include management of A. piceae in Christmas tree plantations. PMID:21867435

  12. Impacts of trunk and soil injections of low rates of imidacloprid on hemlock woolly adelgid (Hemiptera: Adelgidae) and eastern hemlock (Pinales: Pinaceae) health.

    PubMed

    Eisenback, Brian M; Salom, Scott M; Kok, Loke T; Lagalante, Anthony F

    2014-02-01

    Eastern hemlocks (Tsuga canadensis Carrière) at two sites in southwestern Virginia were treated by trunk and soil injections of imidacloprid to determine the insecticide's impact on hemlock woolly adelgid, Adelges tsugae Annand. Treatments were 25, 50, and 100% of the highest labeled dosage rates for both stem and soil injection. Three and 4 yr after treatment, the half and full rates had significantly reduced A. tsugae populations, which were accompanied by increased new hemlock shoot growth and higher hemlock health scores on a visual rating of tree appearance. Imidacloprid and metabolite concentrations in tissue of treated trees were determined by liquid chromatography-tandem mass spectrometry, and A. tsugae density decreased as imidacloprid concentrations increased in wood tissue. There were no observed A. tsugae populations in all trees with imidacloprid tissue concentrations >413 ppb. Olefin, di-hydroxy, and 6-chloro-nicotinic-acid metabolites were the imidacloprid metabolites recovered in the highest concentrations. This suggests that hemlock metabolism of imidacloprid may increase efficacy of the parent compound. Stem and soil treatments of low rates of systemic imidacloprid reduce adelgid populations and promote hemlock health, but still may provide a remnant food source for beneficial predators. PMID:24665708

  13. Hydraulic architecture and photosynthetic capacity as constraints on release from suppression in Douglas-fir and western hemlock.

    PubMed

    Renninger, Heidi J; Meinzer, Frederick C; Gartner, Barbara L

    2007-01-01

    We compared hydraulic architecture, photosynthesis and growth in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), a shade-intolerant species, and western hemlock (Tsuga heterophylla (Raf.) Sarg.), a shade-tolerant species, to study the temporal pattern of release from suppressive shade. In particular, we sought to determine whether hydraulic architecture or photosynthetic capacity is most important in constraining release. The study was conducted at two sites with mixed stands of 10- to 20-year-old Douglas-fir and western hemlock. At one site, the stand had been thinned allowing release of the understory trees, whereas at the other site, the stand remained unthinned. Douglas-fir had lower height growth (from 1998-2003) and lower relative height growth (height growth from 1998 to 2003/height in 1998) than western hemlock. However, relative height growth of released versus suppressed trees was higher in Douglas-fir (130%) than in western hemlock (65%), indicating that, although absolute height growth was less, Douglas-fir did release from suppression. Release seemed to be constrained initially by a limited photosynthetic capacity in both species. Five years after release, Douglas-fir trees had 14 times the leaf area and 1.5 times the leaf nitrogen concentration (N (area)) of suppressed trees. Needles of released western hemlock trees had about twice the maximum assimilation rate (A (max)) at ambient [CO(2)] as needles of suppressed trees and exhibited no photoinhibition at the highest irradiances. After release, trees increased in leaf area, leaf N concentration and overall photosynthetic capacity. Subsequently, hydraulic architecture appeared to constrain release in Douglas-fir and, to a lesser extent, in western hemlock. Released trees had significantly less negative foliar delta(13)C values than suppressed trees and showed a positive relationship between leaf area:sapwood area ratio (A (L)/A (S)) and delta(13)C, suggesting that trees with more leaf area for a given sapwood area experienced a stomatal limitation on carbon gain. Nonetheless, these changes had no significant effects on leaf specific conductivities of suppressed versus released trees of either species, but leaf specific root conductance was significantly lower in released Douglas-fir. PMID:17169904

  14. Water use and carbon exchange of red oak- and eastern hemlock-dominated forests in the northeastern USA: implications for ecosystem-level effects of hemlock woolly adelgid.

    PubMed

    Hadley, Julian L; Kuzeja, Paul S; Daley, Michael J; Phillips, Nathan G; Mulcahy, Thomas; Singh, Safina

    2008-04-01

    Water use and carbon exchange of a red oak-dominated (Quercus rubra L.) forest and an eastern hemlock-dominated (Tsuga canadensis L.) forest, each located within the Harvard Forest in north-central Massachusetts, were measured for 2 years by the eddy flux method. Water use by the red oak forest reached 4 mm day(-1), compared to a maximum of 2 mm day(-1) by the eastern hemlock forest. Maximal carbon (C) uptake rate was also higher in the red oak forest than in the eastern hemlock forest (about 25 versus 15 micromol m(-2) s(-1)). Sap flux measurements indicated that transpiration of red oak, and also of black birch (Betula lenta L.), which frequently replaces eastern hemlock killed by hemlock woolly adelgid (Adelges tsugae Annand.), were almost twice that of eastern hemlock. Despite the difference between species in maximum summertime C assimilation rate, annual C storage of the eastern hemlock forest almost equaled that of the red oak forest because of net C uptake by eastern hemlock during unusually warm fall and spring weather, and a near-zero C balance during the winter. Thus, the effect on C storage of replacing eastern hemlock forest with a forest dominated by deciduous species is unclear. Carbon storage by eastern hemlock forests during fall, winter and spring is likely to increase in the event of climate warming, although this may be offset by C loss during hotter summers. Our results indicate that, although forest water use will decrease immediately following eastern hemlock mortality due to the hemlock woolly adelgid, the replacement of eastern hemlock by deciduous species such as red oak will likely increase summertime water use over current rates in areas where hemlock is a major forest species. PMID:18244947

  15. Assessing the Potential Impacts to Riparian Ecosystems Resulting from Hemlock Mortality in Great Smoky Mountains National Park

    NASA Astrophysics Data System (ADS)

    Roberts, Scott W.; Tankersley, Roger; Orvis, Kenneth H.

    2009-08-01

    Hemlock Woolly Adelgid ( Adelges tsugae) is spreading across forests in eastern North America, causing mortality of eastern hemlock ( Tsuga canadensis [L.] Carr.) and Carolina hemlock ( Tsuga caroliniana Engelm.). The loss of hemlock from riparian forests in Great Smoky Mountains National Park (GSMNP) may result in significant physical, chemical, and biological alterations to stream environments. To assess the influence of riparian hemlock stands on stream conditions and estimate possible impacts from hemlock loss in GSMNP, we paired hardwood- and hemlock-dominated streams to examine differences in water temperature, nitrate concentrations, pH, discharge, and available photosynthetic light. We used a Geographic Information System (GIS) to identify stream pairs that were similar in topography, geology, land use, and disturbance history in order to isolate forest type as a variable. Differences between hemlock- and hardwood-dominated streams could not be explained by dominant forest type alone as forest type yields no consistent signal on measured conditions of headwater streams in GSMNP. The variability in the results indicate that other landscape variables, such as the influence of understory Rhododendron species, may exert more control on stream conditions than canopy composition. The results of this study suggest that the replacement of hemlock overstory with hardwood species will have minimal impact on long-term stream conditions, however disturbance during the transition is likely to have significant impacts. Management of riparian forests undergoing hemlock decline should, therefore, focus on facilitating a faster transition to hardwood-dominated stands to minimize long-term effects on water quality.

  16. Prey suitability and phenology of Leucopis spp. (Diptera: Chamaemyiidae) associated with hemlock woolly adelgid (Hemiptera: Adelgidae) in the Pacific Northwest.

    PubMed

    Grubin, Sarah M; Ross, Darrell W; Wallin, Kimberly F

    2011-12-01

    Leucopis spp. (Diptera: Chamaemyiidae) from the Pacific Northwest previously were identified as potential biological control agents for the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), in the eastern United States. We collected Leucopis spp. larvae from A. tsugae infested western hemlocks in Oregon and Washington and reared them on an unidentified Pineus spp., Pineus strobi (Hartig), Adelges cooleyi (Gillette), Adelges piceae (Ratzeburg), and A. tsugae in three no-choice tests. Leucopis spp. survival on A. tsugae was significantly higher than on A. piceae during the 2010 progrediens generation test and significantly higher than on P. strobi and A. cooleyi during the 2010 sistens generation test. However, across all three tests, some larvae completed development to adult on all four of the alternative adelgid species. Larvae that survived to the adult stage were identified as Leucopis argenticollis Zetterstedt and Leucopis piniperda Malloch. These results suggest that populations of L. argenticollis and L. piniperda in the Pacific Northwest may not be specific to A. tsugae. We also studied the phenology of Leucopis spp. on fourteen A. tsugae infested western hemlock trees in Oregon and Washington over a period of 14 mo. Leucopis spp. larvae were collected year-round, but highest densities coincided with the presence of progrediens and sistens eggs and adults of A. tsugae. There was a positive correlation between Leucopis spp. and A. tsugae abundance. PMID:22217756

  17. Spatial tools for managing hemlock woolly adelgid in the southern Appalachians

    NASA Astrophysics Data System (ADS)

    Koch, Frank Henry, Jr.

    The hemlock woolly adelgid (Adelges tsugae) has recently spread into the southern Appalachians. This insect attacks both native hemlock species (Tsuga canadensis and T. caroliniana ), has no natural enemies, and can kill hemlocks within four years. Biological control displays promise for combating the pest, but counter-measures are impeded because adelgid and hemlock distribution patterns have been detailed poorly. We developed a spatial management system to better target control efforts, with two components: (1) a protocol for mapping hemlock stands, and (2) a technique to map areas at risk of imminent infestation. To construct a hemlock classifier, we used topographically normalized satellite images from Great Smoky Mountains National Park. Employing a decision tree approach that supplemented image spectral data with several environmental variables, we generated rules distinguishing hemlock areas from other forest types. We then implemented these rules in a geographic information system and generated hemlock distribution maps. Assessment yielded an overall thematic accuracy of 90% for one study area, and 75% accuracy in capturing hemlocks in a second study area. To map areas at risk, we combined first-year infestation locations from Great Smoky Mountains National Park and the Blue Ridge Parkway with points from uninfested hemlock stands, recording a suite of environmental variables for each point. We applied four different multivariate classification techniques to generate models from this sample predicting locations with high infestation risk, and used the resulting models to generate risk maps for the study region. All techniques performed well, accurately capturing 70--90% of training and validation samples, with the logistic regression model best balancing accuracy and regional applicability. Areas close to trails, roads, and streams appear to have the highest initial risk, perhaps due to bird- or human-mediated dispersal. Both components of our management system are general enough for use throughout the southern Appalachians. Overlay of derived maps will allow forest managers to reduce the area where they must focus their control efforts and thus allocate resources more efficiently.

  18. The ecology of energy and nutrient fluxes in hemlock forests invaded by hemlock woolly adelgid.

    PubMed

    Stadler, Bernhard; Müller, Thomas; Orwig, David

    2006-07-01

    The hemlock woolly adelgid (HWA, Adelges tsugae Annand) is currently causing a severe decline in vitality and survival of eastern hemlock in North American forests. We analyzed the effects of light HWA infestation on vertical energy and nutrient fluxes from the canopy to the forest floor. Canopy throughfall, litter lysimeters, and laboratory litter microcosms were used to examine the effects of HWA-affected and unaffected throughfall on litter type, leachate, and litter chemistry. Early in the season adelgid infestation caused higher dissolved organic carbon (DOC; +24.6%), dissolved organic nitrogen (DON; +28.5%), and K (+39.3%) fluxes and lower inorganic nitrogen fluxes (-39.8%) in throughfall and in adjacent litter solutions collected beneath infested compared to uninfested trees. Needle litter collected beneath uninfested hemlock had significantly lower N concentrations compared to needles collected beneath infested trees, while no difference in N concentrations was found in birch litter. Bacteria were significantly more abundant on hemlock and birch litter beneath infested trees, while yeasts and filamentous fungi showed no consistent response to HWA throughfall. Litter microcosms showed that less DOC was leaching from birch than from hemlock needles when exposed to HWA throughfall. Overall, NH4-N and DON leachate concentrations were higher from birch than from hemlock litter. Thus, HWA-affected throughfall leads to qualitative and quantitative differences in nitrogen export from the litter layer. The N concentration of hemlock litter did not change with time, but the N concentration in birch litter increased significantly during the course of the experiment, especially when HWA-affected throughfall was applied. We suggest a nonlinear conceptual model for the temporal and vertical transition of energy and nutrient fluxes relative to progressing HWA infestation from a pure hemlock to a birch/maple-dominated forest. Progressive needle loss and changes in needle chemistry are likely to produce a humped-shaped DOC curve, while N fluxes initially decrease as infestation continues but rise eventually with hemlock decline and immigration of hardwood species. These findings suggest that it is necessary to understand the biology and specific physiological/trophic effects of exotic pests on their hosts and associated ecosystem processes in order to decipher the temporal dynamics, direction of change, and functional consequences. PMID:16922328

  19. Spatially nonrandom tree mortality and ingrowth maintain equilibrium pattern in an old-growth Pseudotsuga-Tsuga forest.

    PubMed

    Lutz, James A; Larson, Andrew J; Furniss, Tucker J; Donato, Daniel C; Freund, James A; Swanson, Mark E; Bible, Kenneth J; Chen, Jiquan; Franklin, Jerry F

    2014-08-01

    Mortality processes in old-growth forests are generally assumed to be driven by gap-scale disturbance, with only a limited role ascribed to density-dependent mortality, but these assumptions are rarely tested with data sets incorporating repeated measurements. Using a 12-ha spatially explicit plot censused 13 years apart in an approximately 500-year-old Pseudotsuga-Tsuga forest, we demonstrate significant density-dependent mortality and spatially aggregated tree recruitment. However, the combined effect of these strongly nonrandom demographic processes was to maintain tree patterns in a state of dynamic equilibrium. Density-dependent mortality was most pronounced for the dominant late-successional species, Tsuga heterophylla. The long-lived, early-seral Pseudotsuga menziesii experienced an annual stem mortality rate of 0.84% and no new recruitment. Late-seral species Tsuga and Abies amabilis had nearly balanced demographic rates of ingrowth and mortality. The 2.34% mortality rate for Taxus brevifolia was higher than expected, notably less than ingrowth, and strongly affected by proximity to Tsuga. Large-diameter Tsuga structured both the regenerating conspecific and heterospecific cohorts with recruitment of Tsuga and Abies unlikely in neighborhoods crowded with large-diameter competitors (P < 0.001). Density-dependent competitive interactions strongly shape forest communities even five centuries after stand initiation, underscoring the dynamic nature of even equilibrial old-growth forests. PMID:25230456

  20. Future species composition will affect forest water use after loss of eastern hemlock from southern Appalachian forests.

    PubMed

    Brantley, Steven; Ford, Chelcy R; Vose, James M

    2013-06-01

    Infestation of eastern hemlock (Tsuga canadensis (L.) Carr.) with hemlock woolly adelgid (HWA, Adelges tsugae) has caused widespread mortality of this key canopy species throughout much of the southern Appalachian Mountains in the past decade. Because eastern hemlock is heavily concentrated in riparian habitats, maintains a dense canopy, and has an evergreen leaf habit, its loss is expected to have a major impact on forest processes, including transpiration (E(t)). Our goal was to estimate changes in stand-level E(t) since HWA infestation, and predict future effects of forest regeneration on forest E(t) in declining eastern hemlock stands where hemlock represented 50-60% of forest basal area. We used a combination of community surveys, sap flux measurements, and empirical models relating sap flux-scaled leaf-level transpiration (E(L)) to climate to estimate the change in E(t) after hemlock mortality and forecast how forest E(t) will change in the future in response to eastern hemlock loss. From 2004 to 2011, eastern hemlock mortality reduced annual forest E(t) by 22% and reduced winter E(t) by 74%. As hemlock mortality increased, growth of deciduous tree species--especially sweet birch (Betula lenta L.), red maple (Acer rubrum L.), yellow poplar (Liriodendron tulipifera L.), and the evergreen understory shrub rosebay rhododendron (Rhododendron maximum L.)--also increased, and these species will probably dominate post-hemlock riparian forests. All of these species have higher daytime E(L) rates than hemlock, and replacement of hemlock with species that have less conservative transpiration rates will result in rapid recovery of annual stand E(t). Further, we predict that annual stand E(t) will eventually surpass E(t) levels observed before hemlock was infested with HWA. This long-term increase in forest E(t) may eventually reduce stream discharge, especially during the growing season. However, the dominance of deciduous species in the canopy will result in a permanent reduction in winter E(t) and possible increase in winter stream discharge. The effects of hemlock die-off and replacement with deciduous species will have a significant impact on the hydrologic flux of forest transpiration, especially in winter. These results highlight the impact that invasive species can have on landscape-level ecosystem fluxes. PMID:23865229

  1. Biomechanical Properties of Hemlocks: A Novel Approach to Evaluating Physical Barriers of the Plant–Insect Interface and Resistance to a Phloem-Feeding Herbivore

    PubMed Central

    Ayayee, Paul; Yang, Fuqian; Rieske, Lynne K.

    2014-01-01

    Micromechanical properties that help mediate herbivore access may be particularly important when considering herbivorous insects that feed with piercing-sucking stylets. We used microindentation to quantify the micromechanical properties of hemlock, Tsuga spp., to quantify the hardness of the feeding site of the invasive hemlock woolly adelgid, Adelges tsugae. We measured hardness of the hemlock leaf cushion, the stylet insertion point of the adelgid, across four seasons in a 1 y period for four hemlock species growing in a common garden, including eastern, western, mountain, and northern Japanese hemlocks. Leaf cushion hardness was highest in the fall and winter and lowest in summer for all species. Northern Japanese hemlock had relatively greater hardness than the remaining species. Our data contributes an additional perspective to the existing framework within which greater susceptibility and subsequent mortality of eastern hemlocks is observed. The potential application of microindentation to understanding the nature and relevance of plant mechanical defenses in plant–herbivore interactions is also demonstrated and highlighted. PMID:26462689

  2. Hemlock water dropwort poisoning.

    PubMed Central

    Ball, M. J.; Flather, M. L.; Forfar, J. C.

    1987-01-01

    Severe plant poisoning is relatively uncommon in adults. We report two adults who ingested hemlock water dropwort roots, having mistaken them for wild parsnip. One developed prolonged convulsions, severe metabolic acidosis and respiratory distress requiring mechanical ventilation. The toxin--oenanthotoxin--was detected in the gastric aspirate and measured by high performance liquid chromatography. PMID:3671269

  3. Functional response of ungulate browsers in disturbed eastern hemlock forests

    USGS Publications Warehouse

    Destefano, Stephen

    2015-01-01

    Ungulate browsing in predator depleted North American landscapes is believed to be causing widespread tree recruitment failures. However, canopy disturbances and variations in ungulate densities are sources of heterogeneity that can buffer ecosystems against herbivory. Relatively little is known about the functional response (the rate of consumption in relation to food availability) of ungulates in eastern temperate forests, and therefore how “top down” control of vegetation may vary with disturbance type, intensity, and timing. This knowledge gap is relevant in the Northeastern United States today with the recent arrival of hemlock woolly adelgid (HWA; Adelges tsugae) that is killing eastern hemlocks (Tsuga canadensis) and initiating salvage logging as a management response. We used an existing experiment in central New England begun in 2005, which simulated severe adelgid infestation and intensive logging of intact hemlock forest, to examine the functional response of combined moose (Alces americanus) and white-tailed deer (Odocoileus virginianus) foraging in two different time periods after disturbance (3 and 7 years). We predicted that browsing impacts would be linear or accelerating (Type I or Type III response) in year 3 when regenerating stem densities were relatively low and decelerating (Type II response) in year 7 when stem densities increased. We sampled and compared woody regeneration and browsing among logged and simulated insect attack treatments and two intact controls (hemlock and hardwood forest) in 2008 and again in 2012. We then used AIC model selection to compare the three major functional response models (Types I, II, and III) of ungulate browsing in relation to forage density. We also examined relative use of the different stand types by comparing pellet group density and remote camera images. In 2008, total and proportional browse consumption increased with stem density, and peaked in logged plots, revealing a Type I response. In 2012, stem densities were greatest in girdled plots, but proportional browse consumption was highest at intermediate stem densities in logged plots, exhibiting a Type III (rather than a Type II) functional response. Our results revealed shifting top–down control by herbivores at different stages of stand recovery after disturbance and in different understory conditions resulting from logging vs. simulated adelgid attack. If forest managers wish to promote tree regeneration in hemlock stands that is more resistant to ungulate browsers, leaving HWA-infested stands unmanaged may be a better option than preemptively logging them.

  4. Effect of hemlock and deciduous forest canopy on chemistry of throughfall, West Whately, Massachusetts

    NASA Astrophysics Data System (ADS)

    Rhodes, A. L.; Guswa, A. J.; McNicholas, J.; Mehter, S.; Spence, C.

    2009-12-01

    Ecological forest successions associated with climate change and human disturbance may alter chemical loads to forested New England watersheds. Spread of the invasive insect hemlock wooly adelgid (Adelges tsugae) to eastern North America is causing decline and mortality of the eastern hemlock (Tsuga Canadensis). To begin an evaluation of whether changes in nutrient cycling and rainfall amounts could be altered by this disturbance, we investigated differences in chemistry and volume of rain and throughfall between predominately hemlock and deciduous tree stands in a secondary growth forest located in West Whately, Massachusetts. From 3 June to 25 July 2009, we sampled 14 rain events from two plots: one dominated by eastern hemlock (LAI = 5.6 with 64% of stems as hemlock) and the other dominated by a mix of deciduous species (LAI = 4.7 with 47% of stems as maple and 42% of basal area accounted as white ash). Plots consisted of a 5 x 6 meter grid of 30 collectors for measuring throughfall volume. Half of these were combined into a composite sample and analyzed for pH, acid neutralizing capacity (ANC), dissolved organic carbon (DOC), base cations (Ca2+, Mg2+, Na+, K+), anions (Cl-, NO3-, SO42+), dissolved silica, and specific conductance. Throughfall results were compared against precipitation sampled from a collector located in a nearby field. Over the period of the study, rainfall totaled 311 mm. Throughfall amounted to 242 mm (78%) in the hemlock plot and 276 mm (89%) in the deciduous plot. On an event-by-event basis, the fraction of precipitation that appears as throughfall increases with amount. Throughfall from both hemlock and deciduous plots showed significantly (p < 0.05) higher pH, ANC, DOC, K+, Ca2+, and Mg2+ concentrations than open precipitation, suggesting that the canopy counteracts some acidity in rain and adds organic carbon and nutrients to throughfall. ANC is positively correlated with K+, Ca2+, Mg2+, and DOC, indicating that cation exchange between H+ in rain and base cations on leaf and needle surfaces neutralizes acidity. Mean DOC in throughfall from the hemlock plot (9.5 mg/L) is significantly greater than throughfall from the deciduous plot (6.9 mg/L), and mean ANC is significantly less (ANChemlock = 12.5 μeq/L; ANCdeciduous = 29.7 μeq/L). Should regional succession of hemlock to deciduous forest occur, the amount of throughfall likely will increase. Alkalinity also should increase due to fewer organic acids added to throughfall from a deciduous canopy.

  5. Sharing rotting wood in the shade: ectomycorrhizal communities of co-occurring birch and hemlock seedlings.

    PubMed

    Poznanovic, Sarah K; Lilleskov, Erik A; Webster, Christopher R

    2015-02-01

    Coarse woody debris (CWD) is an important nursery environment for many tree species. Understanding the communities of ectomycorrhizal fungi (ECMF)and the effect of ECMF species on tree seedling condition in CWD will elucidate the potential for ECMF-mediated effects on seedling dynamics. In hemlock-dominated stands, we characterized ECMF communities associated with eastern hemlock (Tsuga canadensis (L.) Carr) and yellow birch (Betula alleghaniensis Britt) seedling pairs growing on CWD. Seedling foliage and CWD were analyzed chemically, and seedling growth, canopy cover, and canopy species determined. Thirteen fungal taxa, 12 associated with birch, and 6 with hemlock, were identified based on morphology and ITS sequencing. Five species were shared by co-occurring birch and hemlock, representing 75% of ectomycorrhizal root tips. Rarified ECMF taxon richness per seedling was higher on birch than hemlock. Nonmetric multidimensional scaling revealed significant correlations between ordination axes, the mutually exclusive ECMF Tomentella and Lactarius spp., foliar N and K, CWD pH, and exchangeable Ca and Mg. Seedlings colonized by Lactarius and T. sublilacina differed significantly in foliar K and N, and CWD differed in exchangeable Ca and Mg. CWD pH and nutrient concentrations were low but foliar macro-nutrient concentrations were not. We hypothesize that the dominant ECMF are adapted to low root carbohydrate availability typical in shaded environments but differ in their relative supply of different nutrients. PMID:25091153

  6. Post-Disturbance Plant Community Dynamics following a Rare Natural-Origin Fire in a Tsuga canadensis Forest

    PubMed Central

    Murray, Bryan D.; Holmes, Stacie A.; Webster, Christopher R.; Witt, Jill C.

    2012-01-01

    Opportunities to directly study infrequent forest disturbance events often lead to valuable information about vegetation dynamics. In mesic temperate forests of North America, stand-replacing crown fire occurs infrequently, with a return interval of 2000–3000 years. Rare chance events, however, may have profound impacts on the developmental trajectories of forest ecosystems. For example, it has been postulated that stand-replacing fire may have been an important factor in the establishment of eastern hemlock (Tsuga canadensis) stands in the northern Great Lakes region. Nevertheless, experimental evidence linking hemlock regeneration to non-anthropogenic fire is limited. To clarify this potential relationship, we monitored vegetation dynamics following a rare lightning-origin crown fire in a Wisconsin hemlock-hardwood forest. We also studied vegetation in bulldozer-created fire breaks and adjacent undisturbed forest. Our results indicate that hemlock establishment was rare in the burned area but moderately common in the scarified bulldozer lines compared to the reference area. Early-successional, non-arboreal species including Rubus spp., Vaccinium angustifolium, sedges (Carex spp.), grasses, Epilobium ciliatum, and Pteridium aquilinium were the most abundant post-fire species. Collectively, our results suggest that competing vegetation and moisture stress resulting from drought may reduce the efficacy of scarification treatments as well as the usefulness of fire for preparing a suitable seedbed for hemlock. The increasing prevalence of growing-season drought suggests that silvicultural strategies based on historic disturbance regimes may need to be reevaluated for mesic species. PMID:22928044

  7. Post-disturbance plant community dynamics following a rare natural-origin fire in a Tsuga canadensis forest.

    PubMed

    Murray, Bryan D; Holmes, Stacie A; Webster, Christopher R; Witt, Jill C

    2012-01-01

    Opportunities to directly study infrequent forest disturbance events often lead to valuable information about vegetation dynamics. In mesic temperate forests of North America, stand-replacing crown fire occurs infrequently, with a return interval of 2000-3000 years. Rare chance events, however, may have profound impacts on the developmental trajectories of forest ecosystems. For example, it has been postulated that stand-replacing fire may have been an important factor in the establishment of eastern hemlock (Tsuga canadensis) stands in the northern Great Lakes region. Nevertheless, experimental evidence linking hemlock regeneration to non-anthropogenic fire is limited. To clarify this potential relationship, we monitored vegetation dynamics following a rare lightning-origin crown fire in a Wisconsin hemlock-hardwood forest. We also studied vegetation in bulldozer-created fire breaks and adjacent undisturbed forest. Our results indicate that hemlock establishment was rare in the burned area but moderately common in the scarified bulldozer lines compared to the reference area. Early-successional, non-arboreal species including Rubus spp., Vaccinium angustifolium, sedges (Carex spp.), grasses, Epilobium ciliatum, and Pteridium aquilinium were the most abundant post-fire species. Collectively, our results suggest that competing vegetation and moisture stress resulting from drought may reduce the efficacy of scarification treatments as well as the usefulness of fire for preparing a suitable seedbed for hemlock. The increasing prevalence of growing-season drought suggests that silvicultural strategies based on historic disturbance regimes may need to be reevaluated for mesic species. PMID:22928044

  8. Nuclei of Tsuga canadensis: Role of Flavanols in Chromatin Organization

    PubMed Central

    Feucht, Walter; Schmid, Markus; Treutter, Dieter

    2011-01-01

    Needle primordia of Tsuga canadensis (hemlock) arising from flank meristems of a shoot apex, form cell lineages consisting of four or eight cells. Within a recently established lineage there is striking uniformity in the pattern of nuclear flavanols. This fact points to an identical transcriptional expression of these flavanols during cell cycling. However two lineages, even if located close together within the same meristem, can be very different in the expression of both cell shape and nuclear flavanol pattern, indicating that epigenetic positional signals are operating in a collective specification of cell lineage development. There is a wide range of nuclear flavanol patterning from a mosaic-like distribution in an activated cell type to a homogenous appearance in silenced cell types. Single cells deriving from lineages are desynchronized because they underlie a signaling network at a higher tissue level which results in stronger epigenetic modifications of their nuclear flavanols. As an extreme case of epigenetic modulation, transient drought conditions caused a drastic reduction of nuclear flavanols. Upon treatment with sucrose or cytokinin, these nuclear flavanols could be fully restored. Analytical determination of the flavanols revealed 3.4 mg/g DW for newly sprouting needles and 19.6 mg/g DW for anthers during meiosis. The roughly 6-fold difference in flavanols is apparently a reflection of the highly diverging organogenetic processes. Collectively, the studies provide strong evidence for combinatorial interplay between cell fate and nuclear flavanols. PMID:22072922

  9. Variation in winter survival of the invasive hemlock woolly adelgid (Hemiptera: Adelgidae) across the eastern United States.

    PubMed

    Trotter, R Talbot; Shields, Kathleen S

    2009-06-01

    The hemlock woolly adelgid (Adelges tsugae Annand) is a small, aphid-like insect native to East Asia and western North America. First documented in the eastern United States in Richmond, VA, in 1951, it has spread to at least 17 states, where it causes increased mortality among both eastern and Carolina hemlocks (Tsuga canadensis Carrière and T. caroliniana Engelmann., respectively). Previous work has suggested low temperatures may limit northward spread of the adelgid. Using recent surveys of A. tsugae mortality across the infested latitudinal gradient of the eastern United States, we show there is a significant positive relationship between minimum winter temperatures and winter survival at the landscape scale. The strength and nature of this relationship, however, varies through time, with absolute minimum winter temperatures explaining almost one half of the tree-level variance in survival in the spring of 2004 but only 9% in 2003. Post hoc analyses of the data suggest the explanatory power of temperature can be improved in ongoing studies by examining seasonal temperature profiles. Previous studies have also suggested adelgid survival may be density dependent, and although these data support this observation, contemporary density is a poor predictor of adelgid survival at the landscape scale. Using landscape estimates of minimum winter temperature, we show two simple methods of estimating landscape-scale adelgid survival rates. Both methods suggest much of the range of T. canadensis in the eastern United States, and the entire range of T. caroliniana falls in areas where winter temperatures will not impose critical limits on A. tsugae populations. PMID:19508766

  10. A terrain-based paired-site sampling design to assess biodiversity losses from eastern hemlock decline

    USGS Publications Warehouse

    Young, J.A.; Smith, D.R.; Snyder, C.D.; Lemarie, D.P.

    2002-01-01

    Biodiversity surveys are often hampered by the inability to control extraneous sources of variability introduced into comparisons of populations across a heterogenous landscape. If not specifically accounted for a priori, this noise can weaken comparisons between sites, and can make it difficult to draw inferences about specific ecological processes. We developed a terrain-based, paired-site sampling design to analyze differences in aquatic biodiversity between streams draining eastern hemlock (Tsuga canadensis) forests, and those draining mixed hardwood forests in Delaware Water Gap National Recreation Area (USA). The goal of this design was to minimize variance due to terrain influences on stream communities, while representing the range of hemlock dominated stream environments present in the park. We used geographic information systems (GIS) and cluster analysis to define and partition hemlock dominated streams into terrain types based on topographic variables and stream order. We computed similarity of forest stands within terrain types and used this information to pair hemlock-dominated streams with hardwood counterparts prior to sampling. We evaluated the effectiveness of the design through power analysis and found that power to detect differences in aquatic invertebrate taxa richness was highest when sites were paired and terrain type was included as a factor in the analysis. Precision of the estimated difference in mean richness was nearly doubled using the terrain-based, paired site design in comparison to other evaluated designs. Use of this method allowed us to sample stream communities representative of park-wide forest conditions while effectively controlling for landscape variability.

  11. Establishment of the hemlock woolly adelgid predator, Laricobius nigrinus (Coleoptera: Derodontidae), in the Eastern United States.

    PubMed

    Mausel, D L; Salom, S M; Kok, L T; Davis, G A

    2010-04-01

    The hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), native to western North America and Asia, was accidentally introduced from Japan to the eastern United States. To potentially establish biological control of A. tsugae, we released a predator endemic to western North America, Laricobius nigrinus Fender (Coleoptera: Derodontidae), from 2003 to 2005, in 22 localities from Georgia to Massachusetts. Release sites spanned the invasive range of the adelgid across five United States Department of Agriculture plant hardiness zones (5a to 7a). Release sizes were 75, 150, 300, 600, or 1,200 adult L. nigrinus per site in the fall, winter, early spring, or sequentially (i.e., fall or winter and early spring). We monitored establishment by annual sampling for L. nigrinus adults with beat sheets and for L. nigrinus larvae by branch clipping. At the end of 3 yr, L. nigrinus was established in 13 of the 22 sites. The following variables were evaluated for their correlation with the numbers of L. nigrinus larvae and adults recovered and for their effect on establishment (scored as F(3) presence/absence): (1) Minimum winter temperature at the release site, (2) A. tsugae density at the time of release, (3) release size, and (4) release season. Only minimum winter temperature was correlated with larval recoveries and no variables were correlated with adult recoveries. Logistic regression modeling found that establishment was positively related to minimum winter temperature and release size. We recommend smaller release sizes in warm areas where establishment probability was high (i.e., zones 7a, 6b, and 6a) and larger release sizes in cold areas where establishment probability was low (i.e., zones 5b and 5a). Releases during fall-early spring and across the range of A. tsugae densities tested were successful. PMID:20388273

  12. Behavioral Responses of Laricobius spp. and Hybrids (Coleoptera: Derodontidae) to Hemlock Woolly Adelgid and Adelgid Host Tree Odors in an Olfactometer.

    PubMed

    Arsenault, Arielle L; Havill, Nathan P; Mayfield, Albert E; Wallin, Kimberly F

    2015-12-01

    The predatory species Laricobius nigrinus (Fender) and Laricobius osakensis (Shiyake and Montgomery) (Coleoptera: Derodontidae) have been released for biological control of hemlock woolly adelgid (Adelges tsugae; Hemiptera: Adelgidae) in eastern North America. L. osakensis is native to Japan, whereas L. nigrinus is endemic to the Pacific Northwest of the United States and Canada. After release, L. nigrinus was found to hybridize with the native eastern species, Laricobius rubidus (LeConte). The purpose of this study is to observe prey location behaviors of these three Laricobius species and L. nigrinus × L. rubidus (Ln × Lr) hybrids. Olfactometer bioassays were used to test response to host odors of adelgid-infested eastern hemlock, uninfested eastern hemlock, and uninfested eastern white pine. Predators reacted in the olfactometer more quickly when adelgid-infested foliage was included as a choice. L. nigrinus preferred infested eastern hemlock over uninfested eastern white pine, and L. rubidus preferred uninfested eastern white pine over uninfested eastern hemlock. Laricobius hybrids did not show a preference for foliage types known to be primary adelgid hosts (eastern hemlock and eastern white pine). Unequal preference by species of Laricobius for host trees of different adelgid prey could therefore be maintaining Laricobius species barriers despite hybridization. L. osakensis for this study were reared in the laboratory, whereas other species in this study were collected from the field, yet still were attracted to infested and uninfested eastern hemlock. This species also responded most quickly in the olfactometer, which is encouraging for successful biological control with this species. PMID:26314036

  13. Comparison of throughfall chemistry in a mature hemlock forest and an early-successional deciduous forest resulting from salvage logging in Whately, Massachusetts

    NASA Astrophysics Data System (ADS)

    Zukswert, J. M.; Rhodes, A. L.; Dwyer, C. H.; Sweezy, T.

    2012-12-01

    Removal of foundation species as a result of disturbance events such as exotic species invasions can alter community composition and ecosystem function. The current hemlock woolly adelgid (Adelges tsugae) infestation in eastern North America that threatens the eastern hemlock (Tsuga canadensis), a foundation species, has motivated salvage logging efforts. Ecological succession resulting from salvage logging of hemlock would eventually produce a deciduous hardwood forest. The chemistry of throughfall beneath a mature hemlock forest canopy is expected to be more acidic than throughfall from a mature deciduous forest canopy because hemlock foliage releases more organic acids and fewer base cations. The chemical composition of throughfall during the early successional transition from hemlock to deciduous is less understood. We hypothesize that throughfall chemistry in a deciduous forest consisting primarily of juvenile trees may be more similar to direct precipitation because leaf area index is smaller. Differences between hemlock throughfall and direct precipitation may be larger due to the denser canopy of these mature trees. We compared the chemical composition of precipitation, hemlock throughfall, and black birch throughfall for 26 precipitation events from 4 March to 30 July 2012. The black birch (Betula lenta) forest patch resulted from salvage logging of hemlocks twenty years ago at the MacLeish Field Station in Whately, MA. From the three plots we measured the volume of water collected and pH, acid neutralizing capacity, dissolved organic carbon (DOC), and concentrations of cations (Ca2+, K+, Na+, Mg2+, NH4+), anions (Cl-, NO3-, SO42-), and dissolved silica. Precipitation totaled 405 mm during the course of the study. Throughfall totaled 347 mm in the black birch plot and 315 mm in the hemlock plot. The proportion of precipitation passing through the forest canopy was smaller in hemlock throughfall than black birch throughfall during small precipitation events (depth < 10 mm), but appeared comparable in larger events. Before leaf emergence, differences between base cation and DOC deposition were not significant (p>0.05, n = 5) for throughfall and direct precipitation. After leaf emergence, base cation and DOC deposition was significantly (p<0.05, n = 21) greater in throughfall than direct precipitation. Additionally, K+, Mg2+, and DOC deposition were significantly greater in hemlock throughfall than black birch throughfall. Black birch throughfall had significantly less H+ deposition than direct precipitation, which suggests that the black birch canopy appears to neutralize the acidity of the precipitation. H+ deposition in hemlock throughfall, however, was not significantly different than precipitation, which could be due to its higher DOC. These results suggest that the successional stage of a deciduous forest canopy has an effect on throughfall chemistry. Lower deposition of base cations prior to and during this juvenile stage could affect soil chemistry by increasing soil acidity and lowering base saturation.

  14. A terrain-based paired-site sampling design to assess biodiversity losses from eastern hemlock decline.

    PubMed

    Young, John A; Smith, David R; Snyder, Craig D; Lemarie, David P

    2002-06-01

    Biodiversity surveys are often hampered by the inability to control extraneous sources of variability introduced into comparisons of populations across a heterogenous landscape. If not specifically accounted for a priori, this noise can weaken comparisons between sites, and can make it difficult to draw inferences about specific ecological processes. We developed a terrain-based, paired-site sampling design to analyze differences in aquatic biodiversity between streams draining eastern hemlock (Tsuga canadensis) forests, and those draining mixed hardwood forests in Delaware Water Gap National Recreation Area (USA). The goal of this design was to minimize variance due to terrain influences on stream communities, while representing the range of hemlock dominated stream environments present in the park. We used geographic information systems (GIS) and cluster analysis to define and partition hemlock dominated streams into terrain types based on topographic variables and stream order. We computed similarity of forest stands within terrain types and used this information to pair hemlock-dominated streams with hardwood counterparts prior to sampling. We evaluated the effectiveness of the design through power analysis and found that power to detect differences in aquatic invertebrate taxa richness was highest when sites were paired and terrain type was included as a factor in the analysis. Precision of the estimated difference in mean richness was nearly doubled using the terrain-based, paired site design in comparison to other evaluated designs. Use of this method allowed us to sample stream communities representative of park-wide forest conditions while effectively controlling for landscape variability. PMID:12108590

  15. Triterpenoids and an alkamide from Ganoderma tsugae.

    PubMed

    Lin, Kai-Wei; Maitraie, Dravidum; Huang, A-Mei; Wang, Jih-Pyang; Lin, Chun-Nan

    2016-01-01

    Ganoderma tsugae is a medicinal mushroom. In a continual study on the bioactive constituents of this fungus, a new lanostanoid, 3β-acetoxy-16α-hydroxy-24ξ-methyl-5α-lanosta-8,25-dien-21-oic acid, named tsugaric acid F (1) and a novel palmitamide, N-(3'α,4'β-dihydroxy-2'β-(hydroxymethyl)-1'β-(cyclobutyl)palmitamide (2) were isolated and characterized from the fruit bodies of G. tsugae, and three novel seco-lanostanoids, 3,4-seco-8α,9α-epoxy-5α-lanosta-21-oic acid 3,4 lactone (5), 3,4-seco-5β-lanosta-7,9(11),4(29)-trien-3,21-dioic acid-3-methyl ester (6), 3,4-seco-5β-lanosta-7,9(11),4(29)-trien-3,21-dioic acid (7), and a known compound, 3-oxo-5α-lanosta-8-en-21-oic acid (4) were prepared from 3. The structures of new compounds, 1, 2, 5-7 were determined by spectroscopic methods. Compounds 1 and 4 showed inhibitory effects on xanthine oxidase (XO) with an IC50 values of 313.3 ± 80.0 and 43.9 ± 29.9 μM, respectively when 7 exhibited potent inhibitory effect on superoxide anion generation in rat neutrophils stimulated with formyl-Met-Leu-Phe (fMLP)/cytochalasin B (CB) with an IC50 values of 1.3 ± 0.2 μM. Compounds 4-7 showed weak cytotoxic activities against PC3 cells. These results indicated that 4 and 7 may be used as cancer chemopreventive agents. PMID:26598137

  16. Forest floor bryophytes of Pseudotsuga menziesii-Tsuga heterophylla stand in Oregon: Influences of substrate and overstory

    USGS Publications Warehouse

    Rambo, T.; Muir, Patricia S.

    1998-01-01

    Species richness and abundance of bryophytes inhabiting forest floor substrates were assessed at two sites in western Oregon. Bryophyte diversity, abundance, and community composition were compared between sites, and between young forest stands (~55 yrs) and old-growth stands (400 + yrs) within each site. Relationships of stand structural features to diversity and community composition were assessed by stratifying sampling between 'diversity' plots placed in areas of greater structural diversity, such as hardwood openings and remnant old-growth trees, and 'matrix' plots situated within the remaining more homogeneous conifer-dominated forest matrix. Richness, particularly for liverworts, was significantly higher in old-growth than young stands, and the two ages differed significantly in community composition. Substrate (ground versus coarse woody debris) and overstory (conifers versus hardwoods) were most strongly correlated with variation in community composition. Relatively open hardwood-dominated diversity plots differed in composition from matrix plots. Bryophyte abundance was lower in denser stands and plots, and positively correlated with canopy gaps, percentage of hardwoods, and incident solar radiation. These results suggest that availability of light may limit bryophyte productivity in these stands.

  17. AVAILABILITY AND UPTAKE OF INORGANIC NITROGEN IN A MIXED OLD-GROWTH CONIFEROUS FOREST

    EPA Science Inventory

    Rates of nitrogen mineralization, nitrification and an index of ammonium and nitrate uptake were monitored in a mixed old-growth stand of Douglas-fir (Pseudotsuga menziesii) western hemlock (Tsuga heterophylla) and western redcedar (Thuja plicata) over a two year period. uried ba...

  18. RELATING FINE ROOT BIOMASS TO SOIL AND CLIMATE CONDITIONS IN THE PACIFIC NORTHWEST

    EPA Science Inventory

    The additive contribution of fine root biomass for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) to the stand average fine root biomass were estimated for eight conifer stands in the Pacific Northwest. Base...

  19. Effects of Forest Succession on Exchangeable Cation Concentrations and Nitrogen Mineralization Rates in Soils Following Logging of Eastern Hemlock Forest, Whately, Massachusetts

    NASA Astrophysics Data System (ADS)

    Rhodes, A. L.; Sweezy, T.; Zukswert, J. M.; Dwyer, C. H.

    2012-12-01

    Ecological forest successions associated with invasive species and human disturbance may alter biogeochemical cycles within New England forests. Spread of the invasive insect hemlock woolly adelgid (Adelges tsugae) to eastern North America is causing mortality of the eastern hemlock (Tsuga canadensis), prompting salvage logging. Regrowth by deciduous hardwood trees is often observed. To evaluate whether changes in nutrient cycling could be altered by forest succession, we investigated exchangeable cation chemistry and nitrogen mineralization rates for soil in a mature, eastern hemlock forest and in a juvenile black birch (Betula lenta) forest in western MA. Eastern hemlock on this property was selectively logged 20 years ago, with black birch regrowth succeeding hemlock. We measured soil pH, exchangeable acidity (Al3+ and H+), exchangeable base cations (Ca2+, Mg2+, Na+, and K+), and nitrogen mineralization rates of organic and mineral horizons for 7 incubation periods between May 2011 - July 2012. We also measured the cation exchange capacity and nitrogen mineralization rates of soils from May - July 2012 (2 incubations) in a mature deciduous forest composed primarily of black birch. At each field site, 7 soil cores were collected. Soil horizons (organic and mineral) were separated and homogenized, and 3 replicates of each composite sample were analyzed for soil geochemistry. Organic soils within the juvenile black birch plot (BB) exhibit a low pH (4.3) similar to hemlock organic soils (HEM, pH=4.2). Surprisingly, exchangeable Al3+—the dominant cation in both plots—is significantly greater in organic soils at BB than at HEM (p<.001), and base saturation is less at BB (29%) than at HEM (46%, p<0.001) due to less Ca2+. There are no significant differences in the exchangeable cation chemistry of the mineral horizons at both sites, suggesting that the acidity difference of organic matter is not due to different soil mineralogy. In comparison, organic soil at the mature black birch site (MBB) is less acidic (pH=4.8) than BB, and it has higher base saturation (59%, p<0.001). The dominant exchangeable cation at MBB is Ca2+, and exchangeable Al3+ is significantly less. These results suggest that acidity of hemlock soils increases after logging, despite hemlocks being succeeded by deciduous trees associated with more basic soils. We hypothesize that clear cutting reduces the supply of base cations to soil from throughfall and litter decomposition, enabling more Al3+ to occupy cation exchange sites. No significant differences in nitrogen mineralization rates were observed between organic soils at BB and HEM during the 2011 growing season; nitrification rates were ~1% at both sites. However, nitrogen mineralization was greater at HEM (p<0.05) during the 2012 growing season due to more NH4+. Additionally, nitrogen mineralization rates at MBB were greater (p<0.01) than both BB and HEM, mostly due to much higher nitrification at MBB (41%). The organic composition of what was previously hemlock soil appears to exhibit a strong control on nitrogen cycling beneath a juvenile deciduous successional stage.

  20. Windthrow and salvage logging in an old-growth hemlock-northern hardwoods forest

    USGS Publications Warehouse

    Lang, K.D.; Schulte, L.A.; Guntenspergen, G.R.

    2009-01-01

    Although the initial response to salvage (also known as, post-disturbance or sanitary) logging is known to vary among system components, little is known about longer term forest recovery. We examine forest overstory, understory, soil, and microtopographic response 25 years after a 1977 severe wind disturbance on the Flambeau River State Forest in Wisconsin, USA, a portion of which was salvage logged. Within this former old-growth hemlock-northern hardwoods forest, tree dominance has shifted from Eastern hemlock (Tsuga canadensis) to broad-leaf deciduous species (Ulmus americana, Acer saccharum, Tilia americana, Populus tremuloides, and Betula alleghaniensis) in both the salvaged and unsalvaged areas. While the biological legacies of pre-disturbance seedlings, saplings, and mature trees were initially more abundant in the unsalvaged area, regeneration through root suckers and stump sprouts was common in both areas. After 25 years, tree basal area, sapling density, shrub layer density, and seedling cover had converged between unsalvaged and salvaged areas. In contrast, understory herb communities differed between salvaged and unsalvaged forest, with salvaged forest containing significantly higher understory herb richness and cover, and greater dominance of species benefiting from disturbance, especially Solidago species. Soil bulk density, pH, organic carbon content, and organic nitrogen content were also significantly higher in the salvaged area. The structural legacy of tip-up microtopography remains more pronounced in the unsalvaged area, with significantly taller tip-up mounds and deeper pits. Mosses and some forest herbs, including Athyrium filix-femina and Hydrophyllum virginianum, showed strong positive responses to this tip-up microrelief, highlighting the importance of these structural legacies for understory biodiversity. In sum, although the pathways of recovery differed, this forest appeared to be as resilient to the compound disturbances of windthrow plus salvage logging as to wind disturbance alone, by most vegetative measures.

  1. Species-specific partitioning of soil water resources in an old-growth Douglas-fir-western hemlock forest.

    PubMed

    Meinzer, Frederick C; Warren, Jeffrey M; Brooks, J Renée

    2007-06-01

    Although tree- and stand-level estimates of forest water use are increasingly common, relatively little is known about partitioning of soil water resources among co-occurring tree species. We studied seasonal courses of soil water utilization in a 450-year-old Pseudotsuga menziesii (Mirb.) Franco-Tsuga heterophylla (Raf.) Sarg. forest in southwestern Washington State. Soil volumetric water content (theta) was continuously monitored with frequency domain capacitance sensors installed at eight depths from 0.2 to 2 m at four locations in the vicinity of each species. Vertical profiles of root distribution and seasonal and daily courses of hydraulic redistribution (HR), sap flow and tree water status were also measured. Mean root area in the upper 60 cm of soil was significantly greater in the vicinity of T. heterophylla trees. However, seasonal water extraction on a root area basis was significantly greater near P. menziesii trees at all depths between 15 and 65 cm, leading to significantly lower water storage in the upper 65 cm of soil near P. menziesii trees at the end of the summer dry season. Greater apparent efficiency of P. menziesii roots at extracting soil water was attributable to a greater driving force for water uptake rather than to differences in root hydraulic properties between the species. The dependence of HR on theta was similar in soil near individuals of both species, but seasonal maximum rates of HR were greater in soil near P. menziesii because minimum values of theta were lower, implying a steeper water potential gradient between the upper and lower soil that acted as a driving force for water efflux from shallow roots. The results provide information on functional traits relevant for understanding the ecological distributions of these species and have implications for spatial variability of processes such as soil respiration and nutrient cycling. PMID:17331905

  2. 78 FR 21344 - Grant of Authority for Subzone Status, Hemlock Semiconductor Corporation, (Polysilicon), Hemlock...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-10

    ... inviting public comment has been given in the Federal Register (76 FR 63282, 10-12-2011; 76 FR 76934, 12-9-2011; 76 FR 81475, 12-28-2011; 77 FR 21082, 4-9-2012; 77 FR 30500, 5-23-2012) and the application has..., (Polysilicon), Hemlock, Michigan Pursuant to its authority under the Foreign-Trade Zones Act of June 18,...

  3. Interaction of Pseudostellaria heterophylla with Fusarium oxysporum f.sp. heterophylla mediated by its root exudates in a consecutive monoculture system

    PubMed Central

    Zhao, Yongpo; Wu, Linkun; Chu, Leixia; Yang, Yanqiu; Li, Zhenfang; Azeem, Saadia; Zhang, Zhixing; Fang, Changxun; Lin, Wenxiong

    2015-01-01

    In this study, quantitative real-time PCR (qPCR) was used to determine the amount of Fusarium oxysporum, an important replant disease pathogen in Pseudostellaria heterophylla rhizospheric soil. Moreover, HPLC was used to identify phenolic acids in root exudates then it was further to explore the effects of the phenolic acid allelochemicals on the growth of F. oxysporum f.sp. heterophylla. The amount of F. oxysporum increased significantly in P. heterophylla rhizosphere soil under a consecutive replant system as monitored through qPCR analysis. Furthermore, the growth of F. oxysporum f.sp. heterophylla mycelium was enhanced by root exudates with a maximum increase of 23.8%. In addition, the number of spores increased to a maximum of 12.5-fold. Some phenolic acids promoted the growth of F. oxysporum f.sp. heterophylla mycelium and spore production. Our study revealed that phenolic acids in the root secretion of P. heterophylla increased long with its development, which was closely related to changes in rhizospheric microorganisms. The population of pathogenic microorganisms such as F. oxysporum in the rhizosphere soil of P. heterophylla also sharply increased. Our results on plant-microbe communication will help to better clarify the cause of problems associated with P. heterophylla under consecutive monoculture treatment. PMID:25645742

  4. Entomopathogenic Activity of a Variety of the Fungus, Colletotrichum acutatum, Recovered from the Elongate Hemlock Scale, Fiorinia externa

    PubMed Central

    Marcelino, José A. P.; Gouli, Svetlana; Parker, Bruce L; Skinner, Margaret; Giordano, Rosanna

    2009-01-01

    A fungal epizootic in populations of Fiorinia externa Ferris (Hemiptera: Diaspididae) infesting hemlock trees, Tsuga canadensis (L.) Carrière (Pinales: Pinaceae) in forests of the Northeastern US has been recently detected. The current known distribution of the epizootic spans 36 sites in New York, Pennsylvania, New Jersey and Connecticut. Colletotrichum acutatum Simmonds var. fioriniae Marcelino and Gouli var. nov. inedit. (Phyllachorales: Phyllachoraceae) was the most prevalent fungus recovered from infected scales. Bioassays indicated that this C. acutatum variety is highly pathogenic to F. externa. Mortality rates of >90 and >55% were obtained for F. externa crawlers and settlers, respectively. Significantly lower mortality levels, ≤ 22%, were obtained when three other species of insects were assayed. C. gleosporioides has also been shown to have pathogenic activity towards a scale insect. The data suggest that C. acutatum var. fioriniae from F. externa epizootics in the US, and the previously reported C. gloeosporioides f. sp. ortheziidae causing Orthezia praelonga epizootics in Brazil, may constitute distinct biotypes of Colletotrichum that have attained the ability to infect insects in addition to the commonly reported plant hosts. PMID:19613442

  5. The triterpenoids of Ganoderma tsugae prevent stress-induced myocardial injury in mice.

    PubMed

    Kuok, Qian-Yu; Yeh, Chen-Yu; Su, Bor-Chyuan; Hsu, Pei-Ling; Ni, Hao; Liu, Ming-Yie; Mo, Fan-E

    2013-10-01

    Ganoderma mushrooms (Lingzhi in Chinese) have well-documented health benefits. Ganoderma tsugae (G. tsugae), one of the ganoderma species, has been commercially cultivated as a dietary supplement. Because G. tsugae has high antioxidant activity and because oxidative stress is often associated with cardiac injury, we hypothesized that G. tsugae protects against cardiac injury by alleviating oxidative stress. We tested the hypothesis using a work-overload-induced myocardial injury model created by challenging mice with isoproterenol (ISO). Remarkably, oral G. tsugae protected the mice from ISO-induced myocardial injury. Moreover, the triterpenoid fraction of G. tsugae, composed of a mixture of nine structurally related ganoderic acids (GAs), provided cardioprotection by inhibiting the ISO-induced expression of Fas/Fas ligand, oxidative stress, and apoptosis. The antioxidant activity of GAs was tested in cultured cardio-myoblast H9c2 cells against the insult of H₂O₂. GAs dissipated the cellular reactive oxygen species imposed by H₂O₂ and prevented cell death. Our findings uncovered the cardioprotective activity of G. tsugae and identified GAs as the bioactive components against cardiac insults. PMID:23610080

  6. Impacts of dwarf mistletoe on the physiology of host Tsuga heterophylla trees as recorded in tree ring C and O stable isotopes

    EPA Science Inventory

    Dwarf mistletoes, obligate, parasitic plants with diminutive aerial shoots, have long-term effects on host tree water relations, hydraulic architecture, and photosynthetic gas exchange and can eventually induce tree death. To investigate long-term impacts of dwarf mistletoe...

  7. Impacts of dwarf mistletoe on the physiology of host Tsuga heterophylla trees as recorded in tree ring C and O stable isotopes

    EPA Science Inventory

    • Dwarf mistletoes, obligate, parasitic plants with diminutive aerial shoots, have long-term effects on host tree water relations, hydraulic architecture, and photosynthetic gas exchange and can eventually induce tree death. • To investigate long-term impacts of dwarf mistletoe...

  8. Maytenus heterophylla and Maytenus senegalensis, two traditional herbal medicines

    PubMed Central

    da Silva, G.; Serrano, R.; Silva, O.

    2011-01-01

    Maytenus heterophylla (Eckl. and Zeyh.) N.K.B. Robson and Maytenus senegalensis (Lam.) Exell are two African shrubs or trees that go under the common name of spike thorn, which belong to the Celastraceae family. Different plant parts of this species are largely used in traditional medicine for infectious and inflammatory diseases treatment. Several studies have been reported for both these species, but there are no recent review articles focusing microscopic, phytochemistry and pharmacological studies. The aim of this review is to summarize the information about these two African traditional medicines. Such kind of data can be applied in future experimental work and may guide future studies, namely in the field of validation of traditional medicine. PMID:22470236

  9. Combining the least cost path method with population genetic data and species distribution models to identify landscape connectivity during the late Quaternary in Himalayan hemlock.

    PubMed

    Yu, Haibin; Zhang, Yili; Liu, Linshan; Qi, Wei; Li, Shicheng; Hu, Zhongjun

    2015-12-01

    Himalayan hemlock (Tsuga dumosa) experienced a recolonization event during the Quaternary period; however, the specific dispersal routes are remain unknown. Recently, the least cost path (LCP) calculation coupled with population genetic data and species distribution models has been applied to reveal the landscape connectivity. In this study, we utilized the categorical LCP method, combining species distribution of three periods (the last interglacial, the last glacial maximum, and the current period) and locality with shared chloroplast, mitochondrial, and nuclear haplotypes, to identify the possible dispersal routes of T. dumosa in the late Quaternary. Then, both a coalescent estimate of migration rates among regional groups and establishment of genetic divergence pattern were conducted. After those analyses, we found that the species generally migrated along the southern slope of Himalaya across time periods and genomic makers, and higher degree of dispersal was in the present and mtDNA haplotype. Furthermore, the direction of range shifts and strong level of gene flow also imply the existence of Himalayan dispersal path, and low area of genetic divergence pattern suggests that there are not any obvious barriers against the dispersal pathway. Above all, we inferred that a dispersal route along the Himalaya Mountains could exist, which is an important supplement for the evolutionary history of T. dumosa. Finally, we believed that this integrative genetic and geospatial method would bring new implications for the evolutionary process and conservation priority of species in the Tibetan Plateau. PMID:26811753

  10. Insight into structure dynamics of soil microbiota mediated by the richness of replanted Pseudostellaria heterophylla.

    PubMed

    Zhao, Yong-Po; Lin, Sheng; Chu, Leixia; Gao, JiangTao; Azeem, Saadia; Lin, Wenxiong

    2016-01-01

    Consecutive monoculture of crops causes serious diseases and significant decline in yield and quality, and microbes in the rhizosphere are closely linked with plant health. Here we systematically studied the structure dynamics of soil microbiota in the monocropping system of Pseudostellaria heterophlla. The results illustrated that the successive cropping of P. heterophylla shifts the diversity and structure of microbial community in rhizosphere soil of P. heterophylla, showing that the diversity of microbial community in rhizosphere soil of P. heterophylla was decreased with the increase of planting years while the structure of microbial community became more deteriorative. Moreover, the population size of typical pathogens increased and the beneficial bacterial population decreased with the increasing years of monoculture, which resulted in the microecological imbalance in P. heterophylla rhizosphere, thereby caused serious replanting diseases in monocropping system. Our results suggested that structure dynamics of rhizosphere microbial communities were mediated by the richness of replanted P. heterophylla, and thus the replant disease result from the imbalanced microbial structure with a higher ratio of pathogens/beneficial bacteria in rhizosphere soil under monocropping regimes. This finding provides a clue to open a new avenue for modulating the root microbiome to enhance the crop production and sustainability. PMID:27188449

  11. From dusk till dawn: nocturnal and diurnal pollination in the epiphyte Tillandsia heterophylla (Bromeliaceae).

    PubMed

    Aguilar-Rodríguez, P A; Krömer, T; García-Franco, J G; MacSwiney G, M C

    2016-01-01

    In order to compare the effectiveness of diurnal and nocturnal pollinators, we studied the reproductive biology and pollinators of Tillandsia heterophylla E. Morren, an epiphytic tank bromeliad endemic to southeastern Mexico. Since anthesis in T. heterophylla is predominantly nocturnal but lasts until the following day, we hypothesised that this bromeliad would receive visits from both diurnal and nocturnal visitors, but that nocturnal visitors would be the most effective pollinators, since they arrive first to the receptive flower, and that bats would be the most frequent nocturnal visitors, given the characteristics of the nectar. Flowering of T. heterophylla began in May and lasted until July. The species is fully self-compatible, with an anthesis that lasts for ca. 15-16 h. Mean volume of nectar produced per flower was 82.21 μl, with a mean sugar concentration of 6.33%. The highest volume and concentration of nectar were found at 20:00 h, with a subsequent decline in both to almost zero over the following 12-h period. T. heterophylla has a generalist pollination system, since at least four different morphospecies of visitors pollinate its flowers: bats, moths, hummingbirds and bees. Most of the pollinating visits corresponded to bats and took place in the early evening, when stigma receptivity had already begun; making bats the probable pollinator on most occasions. However, diurnal pollinators may be important as a 'fail-safe' system by which to guarantee the pollination of T. heterophylla. PMID:25683682

  12. Evaluation of Antitumor and Antioxidant Activity of Melothria heterophylla (Lour.) Cogn

    PubMed Central

    Mondal, A.; Singha, T.; Maity, T. K.; Pal, D.

    2013-01-01

    Melothria heterophylla (Lour.) Cogn., (family-Cucurbitaceae) popularly known as kundari, has been shown to exhibit antioxidant effects. The main objective was to isolate active constituents of the plant extract. In this study, the ability of M. heterophylla to induce apoptosis was studied in Ehrlich ascites carcinoma cells. Treatment of the Ehrlich ascites carcinoma cells with a variety of concentrations of the ethanol extracts of M. heterophylla and gallic acid (100-1000 μM), to determine the sequences of events marked by apoptosis, assayed by the spectrofluorometric method. Gallic acid and rutin were isolated from plant extract which were quantified by high-performance liquid chromatography. Our results indicate that ethanol extracts of M. heterophylla and gallic acid-induced apoptotic cell death in a dose dependent manner could be due to the generation of reactive oxygen species, especially H2O2, which is confirmed by caspase 3 activation. Treatment of Ehrlich ascites carcinoma bearing Swiss albino mice with varied doses (200 and 400 mg/kg, b.w.) of plant extract significantly reduced tumor volume and viable tumor cell count and improved hemoglobin content, RBC count, mean survival time, tumor inhibition, and percentage life span. The enhanced antioxidant status in extract-treated animals were evident from the decline in the levels of lipid peroxidation and increased levels of glutathione, catalase, and superoxide dismutase. The data suggest that M. heterophylla exerts anticancer activity, valuable for application in food and drug products. PMID:24403651

  13. First Cytogenetic Investigation in Populations of Acacia heterophylla, Endemic from La Réunion Island, with Reference to A. melanoxylon

    PubMed Central

    Coulaud, Joelle; Brown, Spencer C.; Siljak-Yakovlev, Sonja

    1995-01-01

    Five populations of tetraploid Acacia heterophylla, endemic from La Réunion island, were compared together and with their Australian diploid relative A. melanoxylon for cytogenetic and DNA characteristics. A. melanoxylon (2n = 26) had 1·59 pg nuclear DNA; A. heterophylla (2n = 4x = 52) had double this value (3·19 pg), and there was no difference between populations within species. Both species had 39 % GC. Interchromosome connections were evident at metaphase and mitotic irregularities at anaphase were twice as frequent in A. heterophylla as in A. melanoxylon, again with no difference between populations within species. These results argue for a recent autotetraploid origin of A. heterophylla from A. melanoxylon. Yet, fluorochrome banding showed that in some A. heterophylla populations, GC-rich bands had slightly changed from the supposed ancestral pattern, probably by means of translocations involving parts of nuclear organizer areas. No clear relation was found between banding patterns and ecological factors. PMID:21247917

  14. A fatal case of apparent water hemlock poisoning.

    PubMed

    Heath, K B

    2001-02-01

    A 14-y-o North American native boy died 20 h after ingesting "wild carrot". He was gathering edible plants with his family on Canadian Thanksgiving. A sample of the plant he ingested couldn't be positively identified but it contained cicutoxin on chromatography. Bioassay caused death in mice which demonstrated clinical signs similar to water hemlock (Cicuta maculata) poisonings. Cicutoxin could not be demonstrated in postmortem tissue or gastric lavage. The boy's clinical signs and laboratory tests were consistent with other reported cases of this poisoning. PMID:11205076

  15. Preparation of nano/submicrometer Ganoderma tsugae and its mutagenic potencies and cytotoxicity.

    PubMed

    Chiang, Yi-Hsien; Chen, Shih-Hsin; Yeh, An-I

    2014-12-17

    This study explored the feasibility of preparing nano/submicrometer particles from Ganoderma tsugae to enhance the contents of bioactive compounds and to assess its mutagenic potencies and cytotoxicity. Hot-water extract, a common product, was employed as a reference. After 3 h of media milling, almost all of the particles were smaller than 1 μm with a number-mean diameter of 0.11 μm. There were about 62% particles smaller than 0.1 μm in terms of number of particles. Scanning electron microscopy (SEM) confirmed the presence of particles at nano/submicrometer scale. The content of 1→3-β-D-glucan in nano/submicrometer G. tsugae was 3.5 times of that in hot-water extract. Both nano/submicrometer and hot-water extract G. tsugae exhibited no mutagenic potential to Salmonella Typhimurium tester strains. Cell toxicity test also confirmed the safety of both nano/submicrometer and hot-water extract G. tsugae. The effect of media milling on the structural change of hyphae was also discussed. PMID:25406501

  16. Polyketide synthases from poison hemlock (Conium maculatum L.).

    PubMed

    Hotti, Hannu; Seppänen-Laakso, Tuulikki; Arvas, Mikko; Teeri, Teemu H; Rischer, Heiko

    2015-11-01

    Coniine is a toxic alkaloid, the biosynthesis of which is not well understood. A possible route, supported by evidence from labelling experiments, involves a polyketide formed by the condensation of one acetyl-CoA and three malonyl-CoAs catalysed by a polyketide synthase (PKS). We isolated PKS genes or their fragments from poison hemlock (Conium maculatum L.) by using random amplification of cDNA ends (RACE) and transcriptome analysis, and characterized three full-length enzymes by feeding different starter-CoAs in vitro. On the basis of our in vitro experiments, two of the three characterized PKS genes in poison hemlock encode chalcone synthases (CPKS1 and CPKS2), and one encodes a novel type of PKS (CPKS5). We show that CPKS5 kinetically favours butyryl-CoA as a starter-CoA in vitro. Our results suggest that CPKS5 is responsible for the initiation of coniine biosynthesis by catalysing the synthesis of the carbon backbone from one butyryl-CoA and two malonyl-CoAs. PMID:26260860

  17. Relatedness defies biogeography: the tale of two island endemics (Acacia heterophylla and A.koa).

    PubMed

    Le Roux, Johannes J; Strasberg, Dominique; Rouget, Mathieu; Morden, Clifford W; Koordom, Megan; Richardson, David M

    2014-10-01

    Despite the normally strong link between geographic proximity and relatedness of recently diverged taxa, truly puzzling biogeographic anomalies to this expectation exist in nature. Using a dated phylogeny, population genetic structure and estimates of ecological niche overlap, we tested the hypothesis that two geographically very disjunct, but morphologically very similar, island endemics (Acacia heterophylla from Runion Island and A.koa from the Hawaiian archipelago) are the result of dispersal between these two island groups, rather than independent colonization events from Australia followed by convergent evolution. Our genetic results indicated that A.heterophylla renders A.koa paraphyletic and that the former colonized the Mascarene archipelago directly from the Hawaiian Islands ?1.4 million yr ago. This colonization sequence was corroborated by similar ecological niches between the two island taxa, but not between A.melanoxylon from Australia (a sister, and presumed ancestral, taxon to A.koa and A.heterophylla) and Hawaiian A.koa. It is widely accepted that the long-distance dispersal of plants occurs more frequently than previously thought. Here, however, we document one of the most exceptional examples of such dispersal. Despite c. 18000km separating A.heterophylla and A.koa, these two island endemics from two different oceans probably represent a single taxon as a result of recent extreme long-distance dispersal. PMID:24942529

  18. Effects of consecutive monoculture of Pseudostellaria heterophylla on soil fungal community as determined by pyrosequencing.

    PubMed

    Wu, Linkun; Chen, Jun; Wu, Hongmiao; Wang, Juanying; Wu, Yanhong; Lin, Sheng; Khan, Muhammad Umar; Zhang, Zhongyi; Lin, Wenxiong

    2016-01-01

    Under consecutive monoculture, the biomass and quality of Pseudostellaria heterophylla declines significantly. In this study, a three-year field experiment was conducted to identify typical growth inhibition effects caused by extended monoculturing of P. heterophylla. Deep pyrosequencing was used to examine changes in the structure and composition of soil fungal community along a three-year gradient of monoculture. The results revealed a distinct separation between the newly planted plot and the two-year, three-year monocultured plots. The Shannon and Simpson diversity indices were significantly higher in the two-year and three-year monoculture soils than in the newly planted soil. Consecutive monoculture of this plant led to a significant increase in relative abundance of Fusarium, Trichocladium and Myrothecium and Simplicillium, etc., but a significant decrease in the relative abundance of Penicillium. Quantitative PCR analysis confirmed a significant increase in Fusarium oxysporum, an agent known to cause wilt and rot disease of P. heterophylla. Furthermore, phenolic acid mixture at a ratio similar to that found in the rhizosphere could promote mycelial growth of pathogenic F. oxysporum. Overall, this study demonstrated that consecutive monoculture of P. heterophylla can alter the fungal community in the rhizosphere, including enrichment of host-specific pathogenic fungi at the expense of plant-beneficial fungi. PMID:27216019

  19. Multi-decade biomass dynamics in an old-growth hemlock-northern hardwood forest, Michigan, USA

    PubMed Central

    2014-01-01

    Trends in living aboveground biomass and inputs to the pool of coarse woody debris (CWD) in an undisturbed, old-growth hemlock-northern hardwood forest in northern MI were estimated from multi-decade observations of permanent plots. Growth and demographic data from seven plot censuses over 47 years (1962–2009), combined with one-time measurement of CWD pools, help assess biomass/carbon status of this landscape. Are trends consistent with traditional notions of late-successional forests as equilibrial ecosystems? Specifically, do biomass pools and CWD inputs show consistent long-term trends and relationships, and can living and dead biomass pools and trends be related to forest composition and history? Aboveground living biomass densities, estimated using standard allometric relationships, range from 360–450 Mg/ha among sampled stands and types; these values are among the highest recorded for northeastern North American forests. Biomass densities showed significant decade-scale variation, but no consistent trends over the full study period (one stand, originating following an 1830 fire, showed an aggrading trend during the first 25 years of the study). Even though total above-ground biomass pools are neither increasing nor decreasing, they have been increasingly dominated, over the full study period, by very large (>70 cm dbh) stems and by the most shade-tolerant species (Acer saccharum and Tsuga canadensis). CWD pools measured in 2007 averaged 151 m3/ha, with highest values in Acer-dominated stands. Snag densities averaged 27/ha, but varied nearly ten-fold with canopy composition (highest in Tsuga-dominated stands, lowest in Acer-dominated); snags constituted 10–50% of CWD biomass. Annualized CWD inputs from tree mortality over the full study period averaged 1.9–3.2 Mg/ha/yr, depending on stand and species composition. CWD input rates tended to increase over the course of the study. Input rates may be expected to increase over longer-term observations because, (a) living biomass is increasingly dominated by very large trees whose dead trunks have longer residence time in the CWD pool, and (b) infrequent major disturbances, thought to be important in the dynamics of these forests, have not occurred during the study period but would be expected to produce major, episodic pulses in CWD input. Few fragments of old-growth cool-temperate forests remain, but such forests can constitute a very large carbon pool on a per-area basis. The carbon sink/source status of these forests remains unclear. While aboveground living biomass at this study site shows no strong aggrading or declining trend over the last half-century, this remains a modest span in the innate time-scale of late-successional forest. The effects of rare disturbances, long-term shifts in composition and size structure, and changes in soil carbon and CWD pools may all influence long-term carbon status. PMID:25289184

  20. Remote detection of hemlock woolly adelgid infestations in southern New Hampshire and Maine

    NASA Astrophysics Data System (ADS)

    Williams, Justin P.

    The hemlock woolly adelgid (HWA) is an invasive pest damaging Eastern and Carolina hemlock on the east coast of the United States. Maine and New Hampshire are currently the northernmost front of HWA spread. Developing methods to remotely detect infested stands is paramount in monitoring the spread of this pest. The effect of HWA on hemlock needle reflectance was evaluated using laboratory spectroscopy, pigment extractions and fluorescence measurements. Hemlock habitat suitability was modeled using MaxEnt software and thirteen environmental predictor variables; overall accuracy was 68.2%. Partition modeling of multi-year (1995-2013) Landsat Thematic Mapper imagery was used to develop classification rules that detect and predict HWA infested areas (R 2 = 0.782). Overall agreement with known HWA infestations was 86.7% in conifer forests, 44.3% in mixed forests and 31.6% in deciduous forests. Targeted field surveys of fourteen stands predicted to be infested resulted in eleven new HWA detections.

  1. AmeriFlux US-Ha2 Harvard Forest Hemlock Site

    SciTech Connect

    Munger, William

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Ha2 Harvard Forest Hemlock Site. Site Description - The forest surrounding the Hemlock site has remained pristine with two exceptions. In the early to mid-1700s, European settlers cleared the majority of the forest for agricultural purposes. Selective harvesting of hemlock and chestnut trees occurred up until the early 1900s, when the chestnut blight killed all of the chestnut trees. In the current forest, about 83% of the total basal area of trees is hemlock. The remainder is equally divided between eastern white pine (Pinus strobus L.) and deciduous species, including red maple (Acer rubrum), red oak (Quercus rubra) and black birch (Betula lenta). A very thick organic layer (10-20 cm or more) covers the soil surface, and highly decayed coarse woody debris is abundant.

  2. Inclination distributions and size measurements of hemlock and red spruce needles

    NASA Technical Reports Server (NTRS)

    Kimes, Daniel S.; Smith, J. A.

    1991-01-01

    Needle inclination angle distributions were plotted for 5 and 10 deg intervals for two hemlock trees and one red spruce. The distributions for the hemlock and spruce were similar, with the peak normal angle occurring between 10 and 20 deg. These distributions are between two theoretical (planophile and spherical) leaf angle distributions. The results can be used as an input to radiative transfer models that require a distribution of the orientation of the scattering elements of the canopy.

  3. Antitumor active polysaccharides from the Chinese mushroom Songshan lingzhi, the fruiting body of Ganoderma tsugae.

    PubMed

    Wang, G; Zhang, J; Mizuno, T; Zhuang, C; Ito, H; Mayuzumi, H; Okamoto, H; Li, J

    1993-06-01

    A systematic method of extraction, fractionation, and purification of polysaccharides from Songshan Lingzhi (Ganoderma tsugae) with antitumor activity was established. Seven glycans with strong antitumor activities were obtained from 14 water-soluble, and 15 water-insoluble fractions: FIo-a, FA-1, FII-1, FIII-2, and FIII-2-a, -b, and -c. FIo-a and FA-1 were protein-containing glucogalactans associated with mannose and fucose. FII-1 was a (1-->3)-beta-D-glucan having a lower protein content. The water-insoluble fractions FIII-2-a, -b, and -c were extracted with alkali, and were found to be protein-containing (1-->3)-beta-D-glucans showing the strongest activity. Chemical properties and structure of each antitumor polysaccharide were compared with three fungi of the Ganoderma family, Kofukitake (G. applanatum), Mannentake (G. lucidum), and Songshan Lingzhi (G. tsugae). PMID:7763875

  4. Large wood dynamics in central Appalachian hemlock headwater ravines

    NASA Astrophysics Data System (ADS)

    Costigan, K. H.; Soltesz, P.; Jaeger, K. L.

    2014-12-01

    Large wood (LW) is a critical component to forested mountain headwater streams contributing significantly to geomorphic and ecological processes. The character of LW is a function of valley recruitment processes that influence LW entering the channel and instream retention processes that influence LW transport through the channel reach. In the central Appalachian Mountains, US, LW dynamics in eastern hemlock-dominated ravines may change due to the invasive insect Hemlock Wooly Adelgid (HWA). However, quantitative LW studies are lacking for this region, which are necessary for effective management of projected HWA-associated change. We examined LW dynamics across central Appalachian headwater streams to identify 1) the current state of LW load, 2) the relative environmental factors that influence LW load, 3) potential signs of HWA impact on LW dynamics, and 4) functional grouping patterns of LW pieces in these systems. In a field study that included 24 sites in Ohio, West Virginia, and Virginia, mean wood density was 36 pieces/100m ± 21 and mean wood volume was 5.6 m3/100m ± 3.5. Most pieces were less than bankfull width suggesting high transportability, but large pieces (>10m) contributed significantly to wood volume, jam formation, and geomorphic function. Central Appalachian LW load was on the lower end of mountain headwater streams, but comparable to the northeastern US. A mixture of recruitment and retention processes influence wood dynamics, but channel retention processes better explain jam dynamics. Specifically, higher wood load was associated with lower forest basal area, smaller channel dimensions, and lower hydraulic driving forces, which is consistent with other studies. We did not detect a significant influence on wood load as a result of HWA infestation of ~20 years, which may reflect a lag period between tree mortality, toppling, and LW load. Pieces clustered in three functional groups of 1) larger, stable pieces that store sediment, stabilize the bank, and create pools, 2) relatively stable pieces that deflect flow and dissipate energy, and 3) smaller pieces associated with flow deflection and energy dissipation composed of mixed stability. This study provides quantitative information on LW dynamics in the central Appalachian region prior to expected environmental change associated with HWA.

  5. Transcriptome Sequencing and Identification of Cold Tolerance Genes in Hardy Corylus Species (C. heterophylla Fisch) Floral Buds

    PubMed Central

    Liu, Qingzhong; Guo, Wei; Zhao, Tiantian; Ma, Qinghua; Wang, Guixi

    2014-01-01

    Background The genus Corylus is an important woody species in Northeast China. Its products, hazelnuts, constitute one of the most important raw materials for the pastry and chocolate industry. However, limited genetic research has focused on Corylus because of the lack of genomic resources. The advent of high-throughput sequencing technologies provides a turning point for Corylus research. In the present study, we performed de novo transcriptome sequencing for the first time to produce a comprehensive database for the Corylus heterophylla Fisch floral buds. Results The C. heterophylla Fisch floral buds transcriptome was sequenced using the Illumina paired-end sequencing technology. We produced 28,930,890 raw reads and assembled them into 82,684 contigs. A total of 40,941 unigenes were identified, among which 30,549 were annotated in the NCBI Non-redundant (Nr) protein database and 18,581 were annotated in the Swiss-Prot database. Of these annotated unigenes, 25,311 and 10,514 unigenes were assigned to gene ontology (GO) categories and clusters of orthologous groups (COG), respectively. We could map 17,207 unigenes onto 128 pathways using the Kyoto Encyclopedia of Genes and Genomes Pathway (KEGG) database. Additionally, based on the transcriptome, we constructed a candidate cold tolerance gene set of C. heterophylla Fisch floral buds. The expression patterns of selected genes during four stages of cold acclimation suggested that these genes might be involved in different cold responsive stages in C. heterophylla Fisch floral buds. Conclusion The transcriptome of C. heterophylla Fisch floral buds was deep sequenced, de novo assembled, and annotated, providing abundant data to better understand the C. heterophylla Fisch floral buds transcriptome. Candidate genes potentially involved in cold tolerance were identified, providing a material basis for future molecular mechanism analysis of C. heterophylla Fisch floral buds tolerant to cold stress. PMID:25268521

  6. A CASE OF ACUTE WATER HEMLOCK (CICUTA MACULATA) POISONING AND DEATH IN CATTLE AFTER INGESTION OF GREEN SEED HEADS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A case of acute water hemlock (Cicuta maculata) poisoning in cattle was reported. Nine cattle died acutely after grazing immature water hemlock seed. Chemical analysis and bioassay confirmation determined that the immature seeds contained the highly toxic long chain diols including cicutoxin, cicu...

  7. Ganoderma tsugae in vivo modulates Th1/Th2 and macrophage responses in an allergic murine model.

    PubMed

    Lin, Jin-Yuarn; Chen, Miaw-Ling; Lin, Bi-Fong

    2006-12-01

    We have reported that Ganoderma tsugae supplementation alleviates bronchoalveolar inflammation in an airway sensitization and challenge model with female BALB/c mice. However, the effects of G. tsugae supplementation in vivo on serum antibody levels, splenocyte and peritoneal microphage immune responses have not yet been determined. In this study, serum antibody levels, cytokines and splenocyte chemical mediators and peritoneal macrophage cultures from ovalbumin (OVA)-sensitized and -challenged mice were examined after continuously consuming G. tsugae supplementation diets for 5 weeks. The results showed that OVA sensitization and challenge significantly (P<0.05) decreased the spontaneous production of IL-2 (Th1) cytokine, but significantly (P<0.05) increased spontaneous and OVA-stimulated IL-4 (Th2) production in splenocyte cultures from experimental mice. OVA administration significantly decreased both spontaneous and LPS/IFN-gamma-stimulated IL-1beta and IL-6 levels in peritoneal macrophage cultures from experimental mice. However, dietary supplementation with G. tsugae significantly increased spontaneous IL-2 level, but slightly decreased spontaneous IL-4 level in cultured splenocyte supernatants in the experimental groups. G. tsugae supplementation enhanced pro-inflammatory cytokines IL-1beta and IL-6 production in cultured peritoneal macrophages. However, the nitric oxide level from cultured peritoneal macrophages and serum OVA-specific IgE and IgG(2a) antibody levels was not significantly affected. These results suggest that OVA sensitization and challenge induced a Th2-skewed splenocyte response and decreased peritoneal macrophage cytokine secretion. G. tsugae supplementation in vivo modulated the Th1/Th2 balance and enhanced macrophage immune responses. However, the supplementation diet could not fully reverse the Th2-skewed responses to level of Th1-skewed responses. PMID:16905232

  8. 77 FR 46373 - Availability of an Environmental Assessment for a Biological Control Agent for Hemlock Woolly...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-03

    ... Animal and Plant Health Inspection Service Availability of an Environmental Assessment for a Biological Control Agent for Hemlock Woolly Adelgid AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION: Notice. SUMMARY: We are advising the public that the Animal and Plant Health Inspection Service...

  9. Components and controls of water flux in an old growth Douglas Fir/western Hemlock ecosystem

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report measurements of rates of sap flow in dominant trees, changes in soil moisture, and evaporation from coarse woody debris in an old-growth Douglas-fir / western hemlock ecosystem at Wind River, Washington during dry periods in summer. The measurements are compared with eddy covariance measu...

  10. The non-competitive blockade of GABAA receptors by an aqueous extract of water hemlock (Cicuta douglasii) tubers.

    PubMed

    Green, Benedict T; Goulart, Camila; Welch, Kevin D; Pfister, James A; McCollum, Isabelle; Gardner, Dale R

    2015-12-15

    Water hemlocks (Cicuta spp.) are acutely toxic members of the Umbellierae family; the toxicity is due to the presence of C17-polyacetylenes such as cicutoxin. There is only limited evidence of noncompetitive antagonism by C17-polyacetylenes at GABAA receptors. In this work with WSS-1 cells, we documented the noncompetitive blockade of GABAA receptors by an aqueous extract of water hemlock (Cicuta douglasii) and modulated the actions of the extract with a pretreatment of 10 μM midazolam. PMID:26415905

  11. Water hemlock poisoning in cattle: Ingestion of immature Cicuta maculata seed as the probable cause.

    PubMed

    Panter, Kip E; Gardner, Dale R; Stegelmeier, Bryan L; Welch, Kevin D; Holstege, Dirk

    2011-01-01

    It is well understood that water hemlock tubers are highly toxic to animals and to humans. However, this is the first time that immature seed from (Cicuta maculata) has been implicated in livestock poisoning. Nine mature Hereford cows from a herd of 81 died in northwestern Utah after ingesting immature seed heads of water hemlock (Cicuta maculata) in late summer. No obvious signs of poisoning were reported as all nine were found dead near the banks of the stream where water hemlock was found. Upon discovery of the dead cows, the remaining 72 cows were immediately removed from the pasture and no further losses occurred. Field necropsy of 3 of the dead cows and follow-up serology and histopathological examination of selected tissues did not identify any bacterial or viral causes. History of ingestion of large quantities of water hemlock seed, the acute nature of the deaths, chemical comparison of seed with toxic tubers and follow-up mouse bioassay testing supported the diagnosis of water hemlock poisoning. Seed heads collected from the neighboring pasture upstream and across the fence from the poisoned cattle and tubers collected from grazed plants were chemically analyzed and found to contain cicutoxin, and high levels of two cicutol-like derivatives (cicutol-#1 and #2) as well as other unidentified polyacetylene compounds. Seeds and tubers from suspected plants were semi-quantified and compared to archive samples of highly toxic tubers used in previous experiments. The immature hemlock seed contained less cicutoxin (0.01 times), but 9.5 and 22.5 times more cicutol-#1 and cicutol-#2 respectively, compared to the archive sample. Tubers from the grazed plants contained 4.6 times more cicutoxin and 9.8 and 18.8 times more cicutol-#1 and cicutol-#2 respectively, compared to the archive sample. Mouse bioassays with water extracts of immature seed and tubers from grazed plants demonstrated both were highly toxic and of greater toxicity when compared to archived sample. PMID:21094658

  12. Macrofossil and Tree-Ring Evidence for a Long-Term Forest Succession and Mid-Holocene Hemlock Decline

    NASA Astrophysics Data System (ADS)

    Filion, Louise; Quinty, François

    1993-07-01

    Paludified dune fields in southern Québec provided a unique opportunity to analyze a mid-Holocene forest succession, ranging from xero-mesophilous forests to treed peatlands, which registered the hemlock decline, a major biostratigraphic event in eastern North America. Our fossil-tree chronology established from 66 radiocarbon dates of tree stems indicates that white pine and hemlock were present at the study site about 6000-5700 yr B.P. Hemlock reached a maximum 4900-4800 yr B.P. and then declined between 4600 and 3800 yr B.P.; the species recovered around 3700 yr B.P. and then decreased when white pine and eastern latch dominated the site after 3000 yr B.P. and between 2600 and 2200 yr B.P., respectively. Tree-ring signatures of fossil hemlocks suggest the continuous influence of biotic factors, possibly insect defoliators, throughout the record, as shown by recurrent suppressed-growth pattern. Microscopic examination of the hemlock fossil stems disclosed no evidence of fungal disease. The hemlock decline was probably caused by regional posthypsithermal climatic changes, toward moister conditions.

  13. Lignans and triterpenoids from Vitex negundo var. heterophylla and their biological evaluation.

    PubMed

    Hu, Ping; Li, Da-Hong; Hu, Xu; Li, Sheng-Ge; Sai, Chun-Mei; Sun, Xiao-Cong; Su, Tong; Bai, Jiao; Wang, Zi-Hou; Li, Zhan-Lin; Hua, Hui-Ming

    2016-06-01

    Three new phenylnaphthalene-type lignans, vitexnegheteroins E-G (1-3), and a new polyoxygenated ursane-type triterpene, vitexnegheteroin H (9), were isolated from the seeds of Vitex negundo var. heterophylla, together with ten known compounds. Their structures were established on the basis of extensive 1D and 2D NMR experiments, as well as their mass spectroscopic data. The absolute configurations of compounds 1 and 2 were determined by comparing their experimental ECD spectra with that calculated by the time-dependent density functional theory (TDDFT) method. The isolates were evaluated for their cytotoxicities against three human cancer cell lines, inhibitory activities on lipopolysaccharide-induced NO production in murine microglial BV-2 cells, and antioxidant activities for ABTS radical scavenging. PMID:27118321

  14. Application of solid-phase extraction to quantitatively determine cyproconazole and tebuconazole in treated wood using liquid chromatography with UV detection.

    PubMed

    Miyauchi, Teruhisa; Mori, Mitsunori; Ito, Katsuhiko

    2005-01-21

    Solid-phase extraction (SPE) procedures were developed to avoid interference during the quantitative determination of cyproconazole and tebuconazole co-existing in wood extractives. Five species of wood were used, Japanese cedar (Cryptomeria japonica), Japanese larch (Larix leptolepis), Yezo spruce (Picea jezoensis), Sakhalin fir (Abies sachalinensis), and western hemlock (Tsuga heterophylla). Methanol extractives from the heartwood of all wood samples, except western hemlock, interfered with the quantitative determination of cyproconazole and tebuconazole using liquid chromatography (LC) with UV detection (LC-UV). SPE with Oasis MCX was effective in avoiding this interference. This method also reduced the time and volume of mobile phase required for LC-UV, since wood extractives with long retention times were also removed. PMID:15700465

  15. Hypoglycemic effect of polysaccharides with different molecular weight of Pseudostellaria heterophylla

    PubMed Central

    2013-01-01

    Abstracts Background The aims of this study were to evaluate the antidiabetic activity and to detect molecular size of Pseudostellaria heterophylla polysaccharide (PHP). Pseudostellaria heterophylla is a medicine extensively used in traditional Chinese medicine formulas to treat diabetes and its complications. Methods Molecular weight of PHP was determined by gel permeation chromatography combined with phenol-sulphuric acid method and the monosaccharides composition was determined by HPLC with a precolumn derivatization. Four polysaccharides with different molecular weight were compared for hypoglycemic active on two animal models both high does alloxan induced type1 diabetic mellitus (T1DM) and high-fat/lower does streptozotocin induced type2 diabetic mellitus (T2DM). Blood sugar, glucose tolerance, and insulin tolerance were detected. Rat serum IL-1β, IL-2, IL-10, Leptin, TNF-α, Acrp30 and CRP were also analyzed by sandwich-ELISA approaches to preliminary probe the hypoglycemic mechanism of PHP. Results The hypoglycemic effects related to molecular size of polysaccharide were more effective against T2DM than T1DM. PHP comprise four monosaccharides of galacturonic acid, glucose, galactose and arabinos. T2DM rats daily receiving oral dose of polysaccharide(100 ~ 400 mg/kg) with 50 ~ 210 kDa molecular weight (PF40) could not only significantly lower blood sugar but also reduce total triglyceride level in serum. PF40 improves in insulin tolerance inhibited the expression of some biomarkers including inflammatory cytokine TNF-α and elevated anti-inflammatory cytokine IL-10, regulated adiponectin Acrp30 and leptin. Conclusions PF40 prevent the cascade of inflammatory events in the treatment of T2DM to block overweight progresses to obesity. PMID:24131482

  16. Chemical characteristics and anti-proliferation activities of Ganoderma tsugae polysaccharides.

    PubMed

    Chien, Rao-Chi; Yen, Ming-Tsung; Tseng, Yu-Hsiu; Mau, Jeng-Leun

    2015-09-01

    Polysaccharides were extracted by hot-water and hot-alkali from four forms of Ganoderma tsugae including mature and baby Ling chih, mycelium and filtrate. Different profiles of proximate composition and monosaccharide constituents, and element contents were found in the extracted polysaccharides from different extractions and different forms. The molecular weight distributions of polysaccharides were 2.8×10(4)-6.5×10(5)Da and their infrared spectra were comparable. The hot-alkali extracted polysaccharides exhibited better anti-proliferation on IMR32 cells than the hot-water extracted polysaccharides, which were in turn more effective than the hot-water extracts. Besides, most hot-water extracts and both extracted polysaccharides exhibited an anti-proliferation effect on Hep G2 cells. However, the hot-water extracts showed less effective in anti-proliferation of IMR32 and Hep G2 cells. Based on the anti-tumor effects, both polysaccharides could be prepared for use in the formulation of nutraceuticals and functional foods. PMID:26005143

  17. Antitumor active protein-containing glycans from the Chinese mushroom songshan lingzhi, Ganoderma tsugae mycelium.

    PubMed

    Zhang, J; Wang, G; Li, H; Zhuang, C; Mizuno, T; Ito, H; Mayuzumi, H; Okamoto, H; Li, J

    1994-07-01

    A water-soluble polysaccharide, FI, extracted from the mycelium of Granoderma tsugae, was fractionated and purified by ion-exchange chromatography, gel filtration, and affinity chromatography. Sixteen polysaccharides obtained were examined for antitumor effects on Sarcoma 180 in mice. The three active polysaccharides obtained were as follows: FIo-a: A glycan-protein complex containing 9.3% protein, and having a hetero-glyco-chain of mannose and xylose. FIo-b-alpha: Molecular weight 10,000, glucan-protein complex containing 25.8% protein. The inhibition ratio was 61.8% against the solid cancer Sarcoma 180/mice; the survival ratio was more than 194% of the control group (100). FA-1-b-alpha: Molecular weight 16,000, a complex of glycan:protein = 42:58 w/w, consisting of glucose as a main component, and associated with arabinose, mannose, xylose, and galactose. This had a tumor inhibition ratio of 56% and a survival ratio of more than 182%. Comparison of active glycan with the fruiting body and mycelium: Among water-soluble polysaccharides of fruiting body, FIo-a and FA-1, with antitumor activity, were both glucogalactan-protein complexes of molecular weight 10,000, but that of mycelium was a homoglucan protein complex in FIo-b-alpha and heteroglucan protein in both FA-1-a and FA-1-b-alpha. The heteroglucan had a low tumor inhibition ratio, but caused a high survival ratio in mice. PMID:7765245

  18. Novel microsatellites for Calibrachoa heterophylla (Solanaceae) endemic to the South Atlantic Coastal Plain of South America1

    PubMed Central

    Silva-Arias, Gustavo Adolfo; Mäder, Geraldo; Bonatto, Sandro L.; Freitas, Loreta B.

    2015-01-01

    Premise of the study: Calibrachoa heterophylla (Solanaceae) is a petunia species restricted to the South Atlantic Coastal Plain of South America and presents a recent history of colonization from continental to coastal environments and diversification following the formation of the Coastal Plain during the Quaternary period. Methods and Results: This study reports a suite of 16 microsatellite loci for C. heterophylla. The applicability of these markers was assessed by genotyping 57 individuals from two natural populations. Of the 16 described loci, 12 were found to be polymorphic. Successful cross-amplification tests were obtained using 12 Calibrachoa species. Conclusions: The development of microsatellite markers will be useful to recover the contemporary history of the colonization of the Coastal Plain and to provide information for the conservation of this endemic species. PMID:26191462

  19. Effect of a supplementation of Euphorbia heterophylla on nutritional meat quality of Guinea pig (Cavia porcellus L.).

    PubMed

    Kouakou, N'Goran David Vincent; Grongnet, Jean-François; Assidjo, Nogbou Emmanuel; Thys, Eric; Marnet, Pierre-Guy; Catheline, Daniel; Legrand, Philippe; Kouba, Maryline

    2013-04-01

    The aim of the present work was to study the effect of dietary supplementation of Euphorbia heterophylla on the quality of the Guinea pig meat. Forty guinea pigs were divided into two groups fed ad libitum during 46 days a Panicum maximum diet (Panicum diet) or a mixed diet (75% Panicum maximum+25% Euphorbia heterophylla) (Paneuphorbia diet) to compare their effects on performances and on the composition of guinea pig tissues and carcass. Daily weight gain, liver weight, carcass yield, and the lipid content of both the carcass and the perirenal fat were significantly increased by the Paneuphorbia diet. Feeding Paneuphorbia diet increased (P<0.05) the n-3 PUFA content in perirenal fat, muscle, liver and in the carcass and decreased (P<0.05) the n-6/n-3 ratios in all these tissues and the carcass. In conclusion, this study shows that Euphorbia heterophylla is a source of n-3 fatty acids which can improve significantly the n-3 PUFA content of Guinea pig meat and carcass. PMID:23305832

  20. A climatic driver for abrupt mid-Holocene vegetation dynamics and the hemlock decline in New England.

    PubMed

    Foster, David R; Oswald, W Wyatt; Faison, Edward K; Doughty, Elaine D; Hansen, Barbara C S

    2006-12-01

    The mid-Holocene decline of eastern hemlock is widely viewed as the sole prehistorical example of an insect- or pathogen-mediated collapse of a North American tree species and has been extensively studied for insights into pest-host dynamics and the consequences to terrestrial and aquatic ecosystems of dominant-species removal. We report paleoecological evidence implicating climate as a major driver of this episode. Data drawn from sites across a gradient in hemlock abundance from dominant to absent demonstrate: a synchronous, dramatic decline in a contrasting taxon (oak); changes in lake sediments and aquatic taxa indicating low water levels; and one or more intervals of intense drought at regional to continental scales. These results, which accord well with emerging climate reconstructions, challenge the interpretation of a biotically driven hemlock decline and highlight the potential for climate change to generate major, abrupt dynamics in forest ecosystems. PMID:17249218

  1. Effects of ammonium and nitrate on nutrient uptake and activity of nitrogen assimilating enzymes in western hemlock

    SciTech Connect

    Knoepp, J.D.; Turner, D.P.; Tingey, D.T.

    1993-01-01

    Western hemlock seedlings were grown in nutrient solutions with ammonium, nitrate or ammonium plus nitrate as nitrogen sources. The objectives were to examine (1) possible selectivity for ammonium or nitrate as an N source, (2) the maintenance of charge balance during ammonium and nitrate uptake, and (3) the activity of the nitrogen assimilating enzymes, nitrate reductase, glutamine synthetase, and glutamine dehydrogenase, in relation to the uptake of different nitrogen sources. The uptake studies revealed that western hemlock takes up ammonium faster than nitrate and that ammonium partially inhibits nitrate uptake. Nitrate reductase activity varied with nitrate availability in root tissue, but showed no response in needles, indicating that most nitrate is reduced in the roots. Results indicate that western hemlock may be adapted to sites where NH(4+) is the predominate N source.

  2. Postglacial vegetation history of Mitkof Island, Alexander Archipelago, southeastern Alaska

    NASA Astrophysics Data System (ADS)

    Ager, Thomas A.; Carrara, Paul E.; Smith, Jane L.; Anne, Victoria; Johnson, Joni

    2010-03-01

    An AMS radiocarbon-dated pollen record from a peat deposit on Mitkof Island, southeastern Alaska provides a vegetation history spanning ˜12,900 cal yr BP to the present. Late Wisconsin glaciers covered the entire island; deglaciation occurred > 15,400 cal yr BP. The earliest known vegetation to develop on the island (˜12,900 cal yr BP) was pine woodland ( Pinus contorta) with alder ( Alnus), sedges (Cyperaceae) and ferns (Polypodiaceae type). By ˜12,240 cal yr BP, Sitka spruce ( Picea sitchensis) began to colonize the island while pine woodland declined. By ˜11,200 cal yr BP, mountain hemlock ( Tsuga mertensiana) began to spread across the island. Sitka spruce-mountain hemlock forests dominated the lowland landscapes of the island until ˜10,180 cal yr BP, when western hemlock ( Tsuga heterophylla) began to colonize, and soon became the dominant tree species. Rising percentages of pine, sedge, and sphagnum after ˜7100 cal yr BP may reflect an expansion of peat bog habitats as regional climate began to shift to cooler, wetter conditions. A decline in alders at that time suggests that coastal forests had spread into the island's uplands, replacing large areas of alder thickets. Cedars ( Chamaecyparis nootkatensis, Thuja plicata) appeared on Mitkof Island during the late Holocene.

  3. Effect of simulated fall heat waves on cold hardiness and winter survival of hemlock looper, Lambdina fiscellaria (Lepidoptera: Geometridae).

    PubMed

    Vallières, Rosemarie; Rochefort, Sophie; Berthiaume, Richard; Hébert, Christian; Bauce, Éric

    2015-02-01

    The hemlock looper (Lambdina fiscellaria) is an important pest of eastern Canadian forests. The ongoing climate warming could modify the seasonal ecology of this univoltine species that lays eggs at the end of summer and overwinters at this stage. Indeed, the increase in frequency and intensity of extreme climatic events such as fall heat waves could interfere with the winter metabolism of the hemlock looper. Moreover, the host plant quality, which influences the quantity of insect energetic reserves, the geographic origin of populations and the conditions prevailing during the cold acclimation period, could cause various responses of this pest to climate warming. The main objective of this study is to determine the impact of these factors on hemlock looper winter biology. In October 2010, hemlock looper eggs initially collected from two geographic areas in the province of Québec, and from parents reared on two host plants, were exposed to fall heat waves of different intensities during 5 consecutive days. Supercooling points and cryoprotectant levels were measured on eggs on four different dates in 2010-2011 and survival rate was measured in April 2011. Our results show that hemlock looper eggs have a very low supercooling point and high levels of trehalose, glucose and mannitol in September and November. However, there is no clear relationship between the concentration of these compounds and the decrease in supercooling points. Contents in trehalose, glucose and mannitol were significantly influenced by fall heat waves and by the origin of the population. Winter survival of eggs from the temperate population was negatively affected by strong heat waves while the boreal population was not affected. This study suggests that the metabolism and winter survival of temperate hemlock looper populations in Québec will be more affected by fall heat waves that will increase in frequency due to climate change, than boreal populations. PMID:25585353

  4. DNA and Flavonoids Leach out from Active Nuclei of Taxus and Tsuga after Extreme Climate Stresses

    PubMed Central

    Feucht, Walter; Schmid, Markus; Treutter, Dieter

    2015-01-01

    Severe over-stresses of climate caused dramatic changes in the intracellular distribution of the flavonoids. This was studied in needles from the current year’s growth of the following species and varieties: Tsuga canadensis, Taxus baccata, T. aurea, T. repens, T. nana, and T. compacta. The mode of steady changes in flavonoids was evaluated by microscopic techniques. Most of the flavonoids stain visibly yellow by themselves. The colorless flavanol subgroup can be stained blue by the DMACA reagent. In mid-summer 2013, outstanding high temperatures and intense photo-oxidative irradiation caused in a free-standing tree of Taxus baccata dramatic heat damage in a limited number of cells of the palisade layers. In these cells, the cytoplasm was burned brown. However, the nucleus maintained its healthy “blue” colored appearance which apparently was a result of antioxidant barrier effects by these flavanols. In late May 2014, excessive rainfall greatly affected all study trees. Collectively, in all study trees, a limited number of the mesophyll nuclei from the needless grown in 2013 and 2014 became overly turgid, enlarged in size and the flavanols leached outward through the damaged nuclear membranes. This diffusive stress event was followed one to three days later by a similar efflux of DNA. Such a complete dissolution of the nuclei in young tissues was the most spectacular phenomenon of the present study. As a common feature, leaching of both flavanols and DNA was markedly enhanced with increasing size and age of the cells. There is evidence that signalling flavonoids are sensitized to provide in nuclei and cytoplasm multiple mutual protective mechanisms. However, this well-orchestrated flavonoid system is broken down by extreme climate events. PMID:27135348

  5. Ecosystem Function in Appalachian Headwater Streams during an Active Invasion by the Hemlock Woolly Adelgid

    PubMed Central

    Northington, Robert M.; Webster, Jackson R.; Benfield, Ernest F.; Cheever, Beth M.; Niederlehner, Barbara R.

    2013-01-01

    Forested ecosystems in the southeastern United States are currently undergoing an invasion by the hemlock woolly adelgid (HWA). Previous studies in this area have shown changes to forest structure, decreases in canopy cover, increases in organic matter, and changes to nutrient cycling on the forest floor and soil. Here, we were interested in how the effects of canopy loss and nutrient leakage from terrestrial areas would translate into functional changes in streams draining affected watersheds. We addressed these questions in HWA-infested watersheds at the Coweeta Hydrologic Laboratory in North Carolina. Specifically, we measured stream metabolism (gross primary production and ecosystem respiration) and nitrogen uptake from 2008 to 2011 in five streams across the Coweeta basin. Over the course of our study, we found no change to in-stream nutrient concentrations. While canopy cover decreased annually in these watersheds, this change in light penetration did not translate to higher rates of in-stream primary production during the summer months of our study. We found a trend towards greater heterotrophy within our watersheds, where in-stream respiration accounted for a much larger component of net ecosystem production than GPP. Additionally, increases in rhododendron cover may counteract changes in light and nutrient availability that occurred with hemlock loss. The variability in our metabolic and uptake parameters suggests an actively-infested ecosystem in transition between steady states. PMID:23613803

  6. Imidacloprid movement in soils and impacts on soil microarthropods in southern Appalachian eastern hemlock stands.

    PubMed

    Knoepp, Jennifer D; Vose, James M; Michael, Jerry L; Reynolds, Barbara C

    2012-01-01

    Imidacloprid is a systemic insecticide effective in controlling the exotic pest (hemlock woolly adelgid) in eastern hemlock () trees. Concerns over imidacloprid impacts on nontarget species have limited its application in southern Appalachian ecosystems. We quantified the movement and adsorption of imidacloprid in forest soils after soil injection in two sites at Coweeta Hydrologic Laboratory in western North Carolina. Soils differed in profile depth, total carbon and nitrogen content, and effective cation exchange capacity. We injected imidacloprid 5 cm into mineral soil, 1.5 m from infested trees, using a Kioritz soil injector. We tracked the horizontal and vertical movement of imidacloprid by collecting soil solution and soil samples at 1 m, 2 m, and at the drip line from each tree periodically for 1 yr. Soil solution was collected 20 cm below the surface and just above the saprolite, and acetonitrile-extractable imidacloprid was determined through the profile. Soil solution and extractable imidacloprid concentrations were determined by high-performance liquid chromatography. Soil solution and extractable imidacloprid concentrations were greater in the site with greater soil organic matter. Imidacloprid moved vertically and horizontally in both sites; concentrations generally declined downward in the soil profile, but preferential flow paths allowed rapid vertical movement. Horizontal movement was limited, and imidacloprid did not move to the tree drip line. We found a negative relationship between adsorbed imidacloprid concentrations and soil microarthropod populations largely in the low-organic-matter site; however, population counts were similar to other studies at Coweeta. PMID:22370410

  7. EFFECTS OF AMMONIUM AND NITRATE ON NUTRIENT UPTAKE AND ACTIVITY OF NITROGEN ASSIMILATING ENZYMES IN WESTERN HEMLOCK

    EPA Science Inventory

    Western hemlock seedlings were grown in nutrient solutions with ammonium, nitrate or ammonium plus nitrate as nitrogen sources. he objectives were to examine (1) possible selectivity for ammonium or nitrate as an N source, (2) the maintenance of charge balance during ammonium and...

  8. 78 FR 21099 - Grant of Authority for Subzone Status, Hemlock Semiconductor, L.L.C., (Polysilicon), Clarksville, TN

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ..., filed 10-5-2011); Whereas, notice inviting public comment has been given in the Federal Register (76 FR 63281-63282, 10-12-2011; 76 FR 76934, 12-9- 2011; 76 FR 81475, 12-28-2011; 77 FR 21082, 4-9-2012; 77 FR... Foreign-Trade Zones Board Grant of Authority for Subzone Status, Hemlock Semiconductor,...

  9. Floral longevity and autonomous selfing are altered by pollination and water availability in Collinsia heterophylla

    PubMed Central

    Jorgensen, Rachael; Arathi, H. S.

    2013-01-01

    Background and Aims A plant investing in reproduction partitions resources between flowering and seed production. Under resource limitation, altered allocations may result in floral trait variations, leading to compromised fecundity. Floral longevity and timing of selfing are often the traits most likely to be affected. The duration of corolla retention determines whether fecundity results from outcrossing or by delayed selfing-mediated reproductive assurance. In this study, the role of pollination schedules and soil water availability on floral longevity and seed production is tested in Collinsia heterophylla (Plantaginaceae). Methods Using three different watering regimes and pollination schedules, effects on floral longevity and seed production were studied in this protandrous, flowering annual. Key Results The results reveal that soil water status and pollination together influence floral longevity with low soil water and hand-pollinations early in the floral lifespan reducing longevity. However, early pollinations under excess water did not extend longevity, implying that resource surplus does not lengthen the outcrossing period. The results also indicate that pollen receipt, a reliable cue for fecundity, accelerates flower drop. Early corolla abscission under drought stress could potentially exacerbate sexual conflict in this protandrous, hermaphroditic species by ensuring self-pollen paternity and enabling male control of floral longevity. While pollination schedules did not affect fecundity, water stress reduced per-capita seed numbers. Unmanipulated flowers underwent delayed autonomous selfing, producing very few seeds, suggesting that inbreeding depression may limit benefits of selfing. Conclusions In plants where herkogamy and dichogamy facilitate outcrossing, floral longevity determines reproductive success and mating system. Reduction in longevity under drought suggests a strong environmental effect that could potentially alter the preferred breeding mode in this mixed-mated species. Extrapolating the findings to unpredictable global drought cycles, it is suggested that in addition to reducing yield, water stress may influence the evolutionary trajectory of plant mating system. PMID:23884393

  10. Expression and Functional Analysis of WRKY Transcription Factors in Chinese Wild Hazel, Corylus heterophylla Fisch.

    PubMed

    Zhao, Tian-Tian; Zhang, Jin; Liang, Li-Song; Ma, Qing-Hua; Chen, Xin; Zong, Jian-Wei; Wang, Gui-Xi

    2015-01-01

    Plant WRKY transcription factors are known to regulate various biotic and abiotic stress responses. In this study we identified a total of 30 putative WRKY unigenes in a transcriptome dataset of the Chinese wild Hazel, Corylus heterophylla, a species that is noted for its cold tolerance. Thirteen full-length of these ChWRKY genes were cloned and found to encode complete protein sequences, and they were divided into three groups, based on the number of WRKY domains and the pattern of zinc finger structures. Representatives of each of the groups, Unigene25835 (group I), Unigene37641 (group II) and Unigene20441 (group III), were transiently expressed as fusion proteins with yellow fluorescent fusion protein in Nicotiana benthamiana, where they were observed to accumulate in the nucleus, in accordance with their predicted roles as transcriptional activators. An analysis of the expression patterns of all 30 WRKY genes revealed differences in transcript abundance profiles following exposure to cold, drought and high salinity conditions. Among the stress-inducible genes, 23 were up-regulated by all three abiotic stresses and the WRKY genes collectively exhibited four different patterns of expression in flower buds during the overwintering period from November to April. The organ/tissue related expression analysis showed that 18 WRKY genes were highly expressed in stem but only 2 (Unigene9262 and Unigene43101) were greatest in male anthotaxies. The expression of Unigene37641, a member of the group II WRKY genes, was substantially up-regulated by cold, drought and salinity treatments, and its overexpression in Arabidopsis thaliana resulted in better seedling growth, compared with wild type plants, under cold treatment conditions. The transgenic lines also had exhibited higher soluble protein content, superoxide dismutase and peroxidase activiety and lower levels of malondialdehyde, which collectively suggets that Unigene37641 expression promotes cold tolerance. PMID:26270529

  11. Expression and Functional Analysis of WRKY Transcription Factors in Chinese Wild Hazel, Corylus heterophylla Fisch

    PubMed Central

    Liang, Li-Song; Ma, Qing-Hua; Chen, Xin; Zong, Jian-Wei; Wang, Gui-Xi

    2015-01-01

    Plant WRKY transcription factors are known to regulate various biotic and abiotic stress responses. In this study we identified a total of 30 putative WRKY unigenes in a transcriptome dataset of the Chinese wild Hazel, Corylus heterophylla, a species that is noted for its cold tolerance. Thirteen full-length of these ChWRKY genes were cloned and found to encode complete protein sequences, and they were divided into three groups, based on the number of WRKY domains and the pattern of zinc finger structures. Representatives of each of the groups, Unigene25835 (group I), Unigene37641 (group II) and Unigene20441 (group III), were transiently expressed as fusion proteins with yellow fluorescent fusion protein in Nicotiana benthamiana, where they were observed to accumulate in the nucleus, in accordance with their predicted roles as transcriptional activators. An analysis of the expression patterns of all 30 WRKY genes revealed differences in transcript abundance profiles following exposure to cold, drought and high salinity conditions. Among the stress-inducible genes, 23 were up-regulated by all three abiotic stresses and the WRKY genes collectively exhibited four different patterns of expression in flower buds during the overwintering period from November to April. The organ/tissue related expression analysis showed that 18 WRKY genes were highly expressed in stem but only 2 (Unigene9262 and Unigene43101) were greatest in male anthotaxies. The expression of Unigene37641, a member of the group II WRKY genes, was substantially up-regulated by cold, drought and salinity treatments, and its overexpression in Arabidopsis thaliana resulted in better seedling growth, compared with wild type plants, under cold treatment conditions. The transgenic lines also had exhibited higher soluble protein content, superoxide dismutase and peroxidase activiety and lower levels of malondialdehyde, which collectively suggets that Unigene37641 expression promotes cold tolerance. PMID:26270529

  12. LC-ESI-MS/MS analysis and pharmacokinetics of heterophyllin B, a cyclic octapeptide from Pseudostellaria heterophylla in rat plasma.

    PubMed

    Zhao, Wai-Ou; Pang, Li; Dong, Ning; Yang, Shu

    2015-11-01

    Heterophyllin B (HB) is a cyclic octapeptide isolated from Pseudostellaria heterophylla. HB is used as the quality control index for evaluating P. heterophylla in the Chinese Pharmacopoeia. A rapid and sensitive LC-ESI-MS/MS method was developed and validated for the analysis of HB in rat plasma. Sample preparation consisted of a solid-phase extraction step for the removal of interference and preconcentration of the target analyte HB and the internal standard N-acetylcysteine before chromatographic analysis by MS/MS detection. The separation of HB and N-acetylcysteine was performed using a Hypersil GOLD C18 column and a mixture of methanol-water (60:40, v/v) containing 10?mmol/L ammonium formate and 0.1% formic acid as the mobile phase. The determination step was optimized in the selected reaction monitoring mode for the highly selective and sensitive quantitation of HB in rat plasma. Intra- and inter-assay precision (as relative standard deviation) was ?9.1%, and accuracy was between 92.6 and 102.7%. The validated method was successfully applied to quantify HB concentrations up to 7?h after tail intravenous injections of 2.08, 4.16 and 8.32?mg/kg HB in rats. The LC-MS/MS method identified the relevant pharmacokinetic parameters of HB and its studied analog. PMID:25967583

  13. Estimating structural attributes of Douglas-fir/western hemlock forest stands from Landsat and SPOT imagery

    NASA Technical Reports Server (NTRS)

    Cohen, Warren B.; Spies, Thomas A.

    1992-01-01

    Relationships between spectral and texture variables derived from SPOT HRV 10 m panchromatic and Landsat TM 30 m multispectral data and 16 forest stand structural attributes is evaluated to determine the utility of satellite data for analysis of hemlock forests west of the Cascade Mountains crest in Oregon and Washington, USA. Texture of the HRV data was found to be strongly related to many of the stand attributes evaluated, whereas TM texture was weakly related to all attributes. Data analysis based on regression models indicates that both TM and HRV imagery should yield equally accurate estimates of forest age class and stand structure. It is concluded that the satellite data are a valuable source for estimation of the standard deviation of tree sizes, mean size and density of trees in the upper canopy layers, a structural complexity index, and stand age.

  14. Chemical Composition and Medicinal Value of the New Ganoderma tsugae var. jannieae CBS-120304 Medicinal Higher Basidiomycete Mushroom.

    PubMed

    Chan, Jannie Siew Lee; Asatiani, Mikheil D; Sharvit, Lital E; Trabelcy, Beny; Barseghyan, Gayane S; Wasser, Solomon P

    2015-01-01

    In this research, the chemical composition and anticancer and antioxidant activity of the new medicinal mushroom Ganoderma tsugae var. jannieae CBS-120304 were evaluated. The chemical composition assay includes amounts of total carbohydrates and proteins, amino acids, fatty acids, micro- and macroelements, and vitamins. The investigated medicinal mushroom seemed to be a rich source of nutritional components. Mycelium accumulated more than 2-fold more total protein compared with the fruiting body and reached 37% and 16% of dry weight, respectively. Carbohydrate content in the fruiting body seemed to be conspicuously higher than in the mycelium (50% of dry weight) and reached 80% of dry weight. Quantification of the identified fatty acids indicated that, in general, palmitic acid, oleic acid, and linoleic acid were the major fatty acids. Toxic elements, such as silver, arsenic, cadmium, and mercury, were found only in trace amounts in mycelium and were not detected in the fruiting body. Furthermore, the 1,1-diphenyl-2-picrylhydrazyl free radical scavenging assay was used to evaluate antioxidant activity. The highest radical scavenging activity was 9.0 mg/mL (65.9%) by ethanol extract. In addition, mycelial extracts were tested to inhibit MCF7 breast cancer cells. Ganoderma tsugae var. jannieae ethyl acetate extract (GTEAE) extract showed high potential by inhibiting reporter activity by more than 70%. Results demonstrated that GTEAE had a strong effect on inhibitory protein κΒα level in the higher concentration used (200 gg/mL), which could be compared with the effect of parthenolide. Furthermore, GTEAE demonstrated strong inhibition of IκΒα phosphorylation. PMID:26559860

  15. Seasonal ecology and thermal constraints of Telenomus spp. (Hymenoptera: Scelionidae), egg parasitoids of the hemlock looper (Lepidoptera: Geometridae).

    PubMed

    Legault, Simon; Hébert, Christian; Blais, Julie; Berthiaume, Richard; Bauce, Eric; Brodeur, Jacques

    2012-12-01

    We describe seasonal patterns of parasitism by Telenomus coloradensis Crawford, Telenomus droozi Muesebeck, Telenomus flavotibiae Pelletier (Hymenoptera: Scelionidae), and Trichogramma spp. (Hymenoptera: Trichogrammatidae), egg parasitoids of the hemlock looper, Lambdina fiscellaria (Guenée) (Lepidoptera: Geometridae), after a 3-yr survey of defoliated stands in the lower St. Lawrence region (Quebec, Canada). Results from sentinel trap sampling indicate that T. coloradensis and T. droozi are the most common species, whereas parasitism by T. flavotibiae and Trichogramma spp. is rare. Telenomus coloradensis and T. droozi show similar seasonal periods of parasitism, both species being active in early spring (late April) at temperatures as low as 4°C. Using thermal threshold (T(0)) and thermal constant (K) for immature development of T. coloradensis males and females from egg to adult emergence, we estimated that the spring progeny emerges in the middle of the summer while hemlock looper eggs are absent from the forest environment. Parasitoid females would then mate and remain in the environment to 1) exploit alternate host species, 2) enter into quiescence and later parasitize eggs laid by hemlock looper females in the fall, 3) enter into a reproductive diapause and parasitize hemlock looper eggs only the next spring, or all of these. Although previous studies have shown that T. coloradensis can overwinter in its immature form within the host egg, our field and laboratory results indicate that in the lower St. Lawrence region, this species principally enters diapause as fertilized females, with a mean supercooling point of -30.6°C in the fall. PMID:23321076

  16. Differential effects of sugar maple, red oak, and hemlock tannins on carbon and nitrogen cycling in temperate forest soils.

    PubMed

    Talbot, Jennifer M; Finzi, Adrien C

    2008-03-01

    Tannins are abundant secondary chemicals in leaf litter that are hypothesized to slow the rate of soil-N cycling by binding protein into recalcitrant polyphenol-protein complexes (PPCs). We studied the effects of tannins purified from sugar maple, red oak, and eastern hemlock leaf litter on microbial activity and N cycling in soils from northern hardwood-conifer forests of the northeastern US. To create ecologically relevant conditions, we applied tannins to soil at a concentration (up to 2 mg g(-1) soil) typical of mineral soil horizons. Sugar maple tannins increased microbial respiration significantly more than red oak or hemlock tannins. The addition of sugar maple tannins also decreased gross N mineralization by 130% and, depending upon the rate of application, decreased net rates of N mineralization by 50-290%. At low concentrations, the decrease in mineralization appeared to be driven by greater microbial-N immobilization, while at higher concentrations the decrease in mineralization was consistent with the formation of recalcitrant PPCs. Low concentrations of red oak and hemlock tannins stimulated microbial respiration only slightly, and did not significantly affect fluxes of inorganic N in the soil. When applied to soils containing elevated levels of protein, red oak and hemlock tannins decreased N mineralization without affecting rates of microbial respiration, suggesting that PPC formation decreased substrate availability for microbial immobilization. Our results indicate that tannins from all three species form recalcitrant PPCs, but that the degree of PPC formation and its attendant effect on soil-N cycling depends on tannin concentration and the pool size of available protein in the soil. PMID:18210159

  17. Diurnal changes in the dielectric properties and water status of eastern hemlock and red spruce from Howland, ME

    NASA Technical Reports Server (NTRS)

    Salas, W. A.; Ranson, K. J.; Rock, B. N.; Moss, D. M.

    1991-01-01

    The diurnal characteristics of microwave dielectric properties and water potential of two conifer species were investigated in July and September, 1990. P-band and C-band radial dielectric profiles of hemlock and red spruce, as well as hemlock diurnal water potential and dielectric profiles, are presented. The resulting radial dielectric profiles matched the regions of the functional sapwood (water transport component of the active xylem) in both species such that the sapwood was characterized by a higher dielectric than the bark and heartwood tissues. This is probably due to characteristic differences in the water content of each tissue. As the hemlocks progressed through their diurnal water potential pattern, the dielectric profile remained static until mid-afternoon. As the tension in the water column relaxed (2 to 3 bars) the dielectric constant decreased by 30 to 40 percent. There are several possible explanations for this phenomenon, and these may relate to the dependency of the dielectric measurements on temperature, salinity, and volumetric water content.

  18. A 10-Year Assessment of Hemlock Decline in the Catskill Mountain Region of New York State Using Hyperspectral Remote Sensing Techniques.

    PubMed

    Hanavan, Ryan P; Pontius, Jennifer; Hallett, Richard

    2015-02-01

    The hemlock woolly adelgid is a serious pest of Eastern and Carolina hemlock in the eastern United States. Successfully managing the hemlock resource in the region depends on careful monitoring of the spread of this invasive pest and the targeted application of management options such as biological control, chemical, or silvicultural treatments. To inform these management activities and test the applicability of a landscape-scale remote sensing effort to monitor hemlock condition, hyperspectral collections, and concurrent ground-truthing in 2001 and 2012 of hemlock condition were compared with field metrics spanning a 10-yr survey in the Catskills region of New York. Fine twig dieback significantly increased from 9 to 15% and live crown ratio significantly decreased from 67 to 56% in 2001 and 2012, respectively. We found a significant shift from 59% "healthy" hemlock in 2001 to only 16% in 2012. However, this shift from healthy to declining classifications was mostly a shift to decline class 2 "early decline". These results indicate that while there has been significant increase in decline symptoms as measured in both field and remote sensing assessments, a majority of the declining areas identified in the resulting spatial coverages remain in the "early decline" category and widespread mortality has not yet occurred. While this slow decline across the region stands in contrast to many reports of mortality within 10 yr, the results from this work are in line with other long-term monitoring studies and indicate that armed with the spatial information provided here, continued management strategies can be focused on particular areas to help control the further decline of hemlock in the region. PMID:26470138

  19. Levels-of-growing-stock cooperative study in douglas-fir: Report No. 13. The Francis study, 1963-90. Forest Service research paper

    SciTech Connect

    Hoyer, G.E.; Andersen, N.A.; Marshall, D.

    1996-04-01

    The levels-of-growing-stock studies in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), were designed to test the influence of treatment regimes by using a wide range of retained growing stock on the development of forest growth, yield, and stand structure. Results of the Francis installation located in the headwaters of the Willapa River in Pacific County, Washington, are summarized from calibration at age 15 through age 42 (completion of 60 feet of height growth from calibration, and the planned course of the experimental thinnings plus 5 years). In addition to the eight basic treatments and control common to the other eight study installations in the region, five additional treatments were added at Francis; four late first thinnings (at age 25), which matched the level of growing stock of four standard fixed treatments, and an unthinned western hemlock (Tsuga heterophylla (Raf.) Sarg.). Estimated Douglas-fir site index (50-year base) of this plantation is 124, a mid site II.

  20. Functional expression of FIP-gts, a fungal immunomodulatory protein from Ganoderma tsugae in Sf21 insect cells.

    PubMed

    Jinn, Tzyy-Rong; Wu, Chi-Ming; Tu, Wu-Chun; Ko, Jiunn-Liang; Tzen, Jason T C

    2006-11-01

    The mushrooms of diverse Lingzhi species have been traditionally consumed as luxurious functional food supplements in Chinese society. FIP-gts, a fungal immunomodulatory protein found in Song-Shan Lingzhi (Ganodera tsugae) has been proposed to possess therapeutic effects on cancer and autoimmune diseases. To produce active FIP-gts for evaluation of oral administration, a recombinant FIP-gts (rFIP-gts) fused with a 6His-tag at its C-terminus was expressed in Sf21 insect cells by the baculovirus expression system. High yield (about 70%) and purity (about 90%) of rFIP-gts was obtained by one-step nickel-affinity chromatography. The correctness of the harvested rFIP-gts was verified by Western blot and MALDI-MS analyses. Optimal expression of rFIP-gts was observed when the Sf21 cells were infected with multiplicity of infection of 10 for 72 h, and the yield was up to 47.2 microg/3 x 10(6) infected cells. The immunomodulatory activity of the purified rFIP-gts was detected as the induction of interleukin 2 released from murine splenocytes. Compared with the rFIP-gts produced in Escherichia coli cells, the rFIP-gts produced in Sf21 cells possessed evidently higher specific immunomodulatory activity. PMID:17090952

  1. The Paleolimnological Record of the North Atlantic Oscillation: Magnetic Properties and Diatom Counts from Hemlock and Conesus Lakes, Western New York State

    NASA Astrophysics Data System (ADS)

    Chaisson, W. P.; Arnold, M. R.; Cottrell, R. D.

    2002-05-01

    Between 1900 and 1930 CE when the NAO index showed large amplitude positive excursions, but the AO index varied at very small amplitudes, drought conditions frequently prevailed in western New York state according the Palmer Drought Index (PDI). Since 1970, when both the NAO and the AO indices show large and progressively increasing positive excursions, the PDI has been generally positive, indicating moisture surpluses in the region. Magnetic properties, including coercivity of remanence, have been measured and the diatoms have been enumerated in sediments from two gravity cores collected from Hemlock and Conesus Lakes. The sediments date from ~1875 CE in the Hemlock core and ~1923 CE in the Conesus core. Variations in magnetic grain-size are interpreted from the coercivity of remanence, with lower coercivity of remanence associated with large grain size. The primary productivity of lakes is interpreted from the Lake Trophic Status Index (LTSI), which is calculated based on known ecologies of several diatom species. In both lakes we find that larger magnetic grain size is associated with greater productivity in the lakes. In the Hemlock core, through the interval corresponding to 1913-1943 coercivity of remanence values declined to 281-259 Oersteds, from late 19th century values that were >350 Oersteds. The bottom of the Conesus core (1923-1938 CE) has the lowest coercivity of remanance values in the record (309-317 Oersteds). LTSI values in the Hemlock samples increase as remanence of coercivity values decline between 1888 and 1920 CE. This reflects an increase in the abundance of the mesoeutrophic Tabellaria fenestrata during this interval. In the Conesus samples the agreement between coercivity of remanence and LTSI is quite close. The range of variation in both LTSI and magnetic grain size is smaller in Conesus than in Hemlock Lake. The diatom assemblage is also quite different in Conesus, dominated by eutrophic Aulacosiera granulata, which are rare or absent at Hemlock Lake. The Hemlock basin is much steeper than than that of Conesus and its water level fluctuates more extremely because it is the reservoir for the city of Rochester. Hemlock Lake is oligotrophic and its drainage basin is heavily forested and lightly populated. Conesus Lake is eutrophic, its shores lined with cottages and the basin is heavily agricultural. In spite of these differences in both natural conditions and anthropogenic factors, the LTSI and magnetic measurements of the two lakes share variance, ostensibly forced by regional climate change. Initial results suggest that the shared component of variance in these proxy indicators can predict variations in regional drought intensity. Regional drought intensity, in turn, seems associated with an uncoupling of AO and NAO variation.

  2. Tree species and soil nutrient profiles in old-growth forests of the Oregon Coast Range

    USGS Publications Warehouse

    Cross, Alison; Perakis, Steven S.

    2011-01-01

    Old-growth forests of the Pacific Northwest provide a unique opportunity to examine tree species – soil relationships in ecosystems that have developed without significant human disturbance. We characterized foliage, forest floor, and mineral soil nutrients associated with four canopy tree species (Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), western redcedar (Thuja plicata Donn ex D. Don), and bigleaf maple (Acer macrophyllum Pursh)) in eight old-growth forests of the Oregon Coast Range. The greatest forest floor accumulations of C, N, P, Ca, Mg, and K occurred under Douglas-fir, primarily due to greater forest floor mass. In mineral soil, western hemlock exhibited significantly lower Ca concentration and sum of cations (Ca + Mg + K) than bigleaf maple, with intermediate values for Douglas-fir and western redcedar. Bigleaf maple explained most species-based differences in foliar nutrients, displaying high concentrations of N, P, Ca, Mg, and K. Foliar P and N:P variations largely reflected soil P variation across sites. The four tree species that we examined exhibited a number of individualistic effects on soil nutrient levels that contribute to biogeochemical heterogeneity in these ecosystems. Where fire suppression and long-term succession favor dominance by highly shade-tolerant western hemlock, our results suggest a potential for declines in both soil Ca availability and soil biogeochemical heterogeneity in old-growth forests.

  3. The effects of partial cutting on stand structure and growth of western hemlock-Sitka spruce stands in southeast Alaska

    USGS Publications Warehouse

    Deal, R.L.; Tappeiner, J.C.

    2002-01-01

    The effects of partial cutting on species composition, new and residual-tree cohorts, tree size distribution, and tree growth was evaluated on 73 plots in 18 stands throughout southeast Alaska. These partially cut stands were harvested 12-96 years ago, when 16-96% of the former stand basal area was removed. Partial cutting maintained stand structures similar to uncut old-growth stands, and the cutting had no significant effects on tree species composition. The establishment of new-tree cohorts was positively related to the proportion of basal-area cut. The current stand basal area, tree species composition, and stand growth were significantly related to trees left after harvest (p < 0.001). Trees that were 20-80 cm dbh at the time of cutting had the greatest tree-diameter and basal-area growth and contributed the most to stand growth. Diameter growth of Sitka spruce and western hemlock was similar, and the proportion of stand basal-area growth between species was consistent for different cutting intensities. Concerns about changing tree species composition, lack of spruce regeneration, and greatly reduced stand growth and vigor with partial cuts were largely unsubstantiated. Silvicultural systems based on partial cutting can provide rapidly growing trees for timber production while maintaining complex stand structures with mixtures of spruce and hemlock trees similar to oldgrowth stands.

  4. Geological and climatic changes in quaternary shaped the evolutionary history of Calibrachoa heterophylla, an endemic South-Atlantic species of petunia

    PubMed Central

    2013-01-01

    Background The glacial and interglacial cycles that characterized the Quaternary greatly affected the distribution and genetic diversity of plants. In the Neotropics, few phylogeographic studies have focused on coastal species outside of the Atlantic Rainforest. Climatic and sea level changes during the Quaternary played an important role in the evolutionary history of many organisms found in coastal regions. To contribute to a better understanding of plant evolution in this environment in Southern South America, we focused on Calibrachoa heterophylla (Solanaceae), an endemic and vulnerable wild petunia species from the South Atlantic Coastal Plain (SACP). Results We assessed DNA sequences from two cpDNA intergenic spacers and analyzed them using a phylogeographic approach. The present phylogeographic study reveals the influence of complex geologic and climatic events on patterns of genetic diversification. The results indicate that C. heterophylla originated inland and subsequently colonized the SACP; the data show that the inland haplogroup is more ancient than the coastal one and that the inland was not affected by sea level changes in the Quaternary. The major diversification of C. heterophylla that occurred after 0.4 Myr was linked to sea level oscillations in the Quaternary, and any diversification that occurred before this time was obscured by marine transgressions that occurred before the coastal sand barrier’s formation. Results of the Bayesian skyline plot showed a recent population expansion detected in C. heterophylla seems to be related to an increase in temperature and humidity that occurred at the beginning of the Holocene. Conclusions The geographic clades have been formed when the coastal plain was deeply dissected by paleochannels and these correlate very well with the distributional limits of the clades. The four major sea transgressions formed a series of four sand barriers parallel to the coast that progressively increased the availability of coastal areas after the regressions and that may have promoted the geographic structuring of genetic diversity observed today. The recent population expansion for the entire species may be linked with the event of marine regression after the most recent sea transgression at ~5 kya. PMID:23987105

  5. Ent-trachyloban-19-oic acid isolated from Iostephane heterophylla as a promising antibacterial agent against Streptococcus mutans biofilms.

    PubMed

    Hernández, Dulce M; Díaz-Ruiz, Gloria; Rivero-Cruz, Blanca E; Bye, Robert A; Aguilar, María Isabel; Rivero-Cruz, J Fausto

    2012-04-01

    From the roots of Iostephane heterophylla, six known compounds, namely, ent-trachyloban-19-oic acid (1), the mixture of ent-kaur-16-en-19-oic acid (2) and ent-beyer-15-en-19-oic acid (3), xanthorrhizol (4), 16α-hydroxy-ent-kaurane (5) and 16α-hydroxy-ent-kaur-11-en-19-oic acid (6) were isolated using a bioassay-guided fractionation method. The known compounds (1-6) were identified by comparison of their spectroscopic data with reported values in the literature. In an attempt to increase the resultant antimicrobial activity of 1 and 4, a series of reactions was performed on ent-trachyloban-19-oic acid (1) and xanthorrhizol (4), to obtain derivatives 1a, 1b, and 4a-4d. All the isolated compounds (1-6) and the derivatives 1a, 1b, and 4a-4d were evaluated for their antimicrobial activity against two oral pathogens, Streptococcus mutans and Porphyromonas gingivalis associated with caries and periodontal disease, respectively. Compounds 1, 1b, 2+3, 4 and 4d inhibited the growth of S. mutans with concentrations ranging from 4.1 μg/mL to 70.5 μg/mL. No significant activity was found on P. gingivalis except for 4 with an MIC of 6.8 μg/mL. The ability of 1, 1b, 2+3, 4 and 4d to inhibit biofilm formation by S. mutans was evaluated. It was found that 1, 1b, 4 and 4d interfered with the establishment of S. mutans biofilms, inhibiting their development at 32.5, 125.0, 14.1 and 24.4 μg/mL, respectively. PMID:22245083

  6. Quantitative determination of benzalkonium chloride in treated wood by solid-phase extraction followed by liquid chromatography with ultraviolet detection.

    PubMed

    Miyauchi, Teruhisa; Mori, Mitsunori; Ito, Katsuhiko

    2005-11-18

    Ammoniacal copper quat (ACQ) compound wood preservative is comprised of copper and quaternary ammonium compounds with benzalkonium chloride (BAC) as the active ingredient. Solid-phase extraction (SPE) followed by liquid chromatography with ultraviolet detection (LC-UV) was developed for quantitative determination of BAC in treated wood. Five species of wood were used, Japanese cedar (Cryptomeria japonica), Japanese larch (Larix leptolepis), Yezo spruce (Picea jezoensis), Sakhalin fir (Abies sachalinensis), and western hemlock (Tsuga heterophylla). BAC used in the present study was composed of 66% C12, 33% C14 and less than 1% C16. BAC was added to each wood species (500 mg) then extracted with HCl-ethanol (20 ml) and quantitatively determined with LC-UV (262 nm). Wood extractives from the heartwood of each species, except western hemlock, interfered with quantitative determination of BAC, but SPE with an Oasis MCX cartridge was effective in preventing this. Using the present methods, BAC homologue peaks were clearly confirmed without interference. Recoveries from wood ranged from 92 to 101% and the limit of quantitation was approximately 240 microg/g wood for the C12 and C14 homologues. PMID:16275285

  7. Tree-ring stable isotopes record the impact of a foliar fungal pathogen on CO(2) assimilation and growth in Douglas-fir.

    PubMed

    Saffell, Brandy J; Meinzer, Frederick C; Voelker, Steven L; Shaw, David C; Brooks, J Renée; Lachenbruch, Barbara; McKay, Jennifer

    2014-07-01

    Swiss needle cast (SNC) is a fungal disease of Douglas-fir (Pseudotsuga menziesii) that has recently become prevalent in coastal areas of the Pacific Northwest. We used growth measurements and stable isotopes of carbon and oxygen in tree-rings of Douglas-fir and a non-susceptible reference species (western hemlock, Tsuga heterophylla) to evaluate their use as proxies for variation in past SNC infection, particularly in relation to potential explanatory climate factors. We sampled trees from an Oregon site where a fungicide trial took place from 1996 to 2000, which enabled the comparison of stable isotope values between trees with and without disease. Carbon stable isotope discrimination (Δ(13)C) of treated Douglas-fir tree-rings was greater than that of untreated Douglas-fir tree-rings during the fungicide treatment period. Both annual growth and tree-ring Δ(13)C increased with treatment such that treated Douglas-fir had values similar to co-occurring western hemlock during the treatment period. There was no difference in the tree-ring oxygen stable isotope ratio between treated and untreated Douglas-fir. Tree-ring Δ(13)C of diseased Douglas-fir was negatively correlated with relative humidity during the two previous summers, consistent with increased leaf colonization by SNC under high humidity conditions that leads to greater disease severity in following years. PMID:24330052

  8. The Application of Stomatal Frequency Analysis As A Proxy For Paleo-atmospheric Co2: Calibration and Proxy-validation

    NASA Astrophysics Data System (ADS)

    Kouwenberg, L. L. R.; Wagner, F.; Kürschner, W. M.; Visscher, H.

    Stomata regulate gas-exchange in leaves and their frequency on leaves has a profound influence on the intake of CO2 and the loss of water through the stomata. Experiments and analysis of leaves that have grown naturally under the historical CO2 levels of the past 200 years have demonstrated that many plant species, especially woody an- giosperms, show a reduction in stomatal frequency in relation to a rise in atmospheric CO2. This decrease in stomatal frequency restricts water loss, while the CO2 intake is not substantially reduced due to the higher CO2 concentration in the atmosphere. This species-specific response has been successfully used to reconstruct past CO2 lev- els from the stomatal frequency on fossil leaves after careful calibration to a series of known atmospheric CO2 levels. Methods to obtain such a calibration, are discussed by example of two tree taxa, the tree birch (Betula pubescens/pendula) and the west- ern hemlock (Tsuga heterophylla). The effective use of stomatal frequency analysis as a proxy of atmospheric CO2 requires validation by determination of the influence of other factors such as light availability, humidity, temperature and leaf age on stom- atal frequency. The (dis)advantages of using experiments vs material from naturally grown trees for validation and calibration will be discussed. For angiosperm species, such as Betula, the influence of other factors besides CO2 on stomatal frequency is shown to be of a lesser magnitude when the stomatal index (the number of stomata as a proportion of epidermal cells) is used instead of the stomatal density (the number of stomata per mm2 leaf area). Stomatal frequency in Tsuga heterophylla is not influ- enced by light regime or leaf age, and the observed reduction in stomatal frequency related to the CO2 rise of the last century cannot be explained by trends in precip- itation or temperature as apparent in local climate records. Thus, these two species are considered highly suitable as proxies for paleo-atmospheric CO2 reconstructions. High resolution paleo-atmospheric CO2 records for the Holocene based on fossil Be- tula and Tsuga heterophylla leaves will be briefly discussed.

  9. Ganoderma tsugae Extract Inhibits Growth of HER2-Overexpressing Cancer Cells via Modulation of HER2/PI3K/Akt Signaling Pathway

    PubMed Central

    Kuo, Han-Peng; Hsu, Shih-Chung; Li, Jhy-Wei; Tseng, Hsiu-Hsueh; Chuang, Tzu-Chao; Liu, Jah-Yao; Chen, Shih-Jung; Su, Muh-Hwan; Cheng, Yung-Chi; Chou, Wei-Yuan; Kao, Ming-Ching

    2013-01-01

    Ganoderma, also known as Lingzhi or Reishi, has been used for medicinal purposes in Asian countries for centuries. It is a medicinal fungus with a variety of biological properties including immunomodulatory and antitumor activities. In this study, we investigated the molecular mechanisms by which Ganoderma tsugae (GT), one of the most common species of Ganoderma, inhibits the proliferation of HER2-overexpressing cancer cells. Here, we show that a quality assured extract of GT (GTE) inhibited the growth of HER2-overexpressing cancer cells in vitro and in vivo and enhanced the growth-inhibitory effect of antitumor drugs (e.g., taxol and cisplatin) in these cells. We also demonstrate that GTE induced cell cycle arrest by interfering with the HER2/PI3K/Akt signaling pathway. Furthermore, GTE curtailed the expression of the HER2 protein by modulating the transcriptional activity of the HER2 gene and the stability/degradation of the HER2 protein. In conclusion, this study suggests that GTE may be a useful adjuvant therapeutic agent in the treatment of cancer cells that highly express HER2. PMID:23662119

  10. Fire-mediated pathways of stand development in Douglas-fir/ western hemlock forests of the Pacific Northwest, USA.

    PubMed

    Tepley, Alan J; Swanson, Frederick J; Spies, Thomas A

    2013-08-01

    Forests dominated by Douglas-fir and western hemlock in the Pacific Northwest of the United States have strongly influenced concepts and policy concerning old-growth forest conservation. Despite the attention to their old-growth characteristics, a tendency remains to view their disturbance ecology in relatively simple terms, emphasizing infrequent, stand-replacing (SR) fire and an associated linear pathway toward development of those old-growth characteristics. This study uses forest stand- and age-structure data from 124 stands in the central western Cascades of Oregon to construct a conceptual model of stand development under the mixed-severity fire regime that has operated extensively in this region. Hierarchical clustering of variables describing the age distributions of shade-intolerant and shade-tolerant species identified six groups, representing different influences of fire frequency and severity on stand development. Douglas-fir trees > 400 years old were found in 84% of stands, yet only 18% of these stands (15% overall) lack evidence of fire since the establishment of these old trees, whereas 73% of all stands show evidence of at least one non-stand-replacing (NSR) fire. Differences in fire frequency and severity have contributed to multiple development pathways and associated variation in contemporary stand structure and the successional roles of the major tree species. Shade-intolerant species form a single cohort following SR fire, or up to four cohorts per stand in response to recurring NSR fires that left living trees at densities up to 45 trees/ha. Where the surviving trees persist at densities of 60-65 trees/ha, the postfire cohort is composed only of shade-tolerant species. This study reveals that fire history and the development of old-growth forests in this region are more complex than characterized in current stand-development models, with important implications for maintaining existing old-growth forests and restoring stands subject to timber management. PMID:24015517

  11. Potent In Vitro Protection Against PM[Formula: see text]-Caused ROS Generation and Vascular Permeability by Long-Term Pretreatment with Ganoderma tsugae.

    PubMed

    Tseng, Chia-Yi; Chung, Meng-Chi; Wang, Jhih-Syuan; Chang, Yu-Jung; Chang, Jing-Fen; Lin, Chin-Hung; Hseu, Ruey-Shyang; Chao, Ming-Wei

    2016-04-01

    Epidemiological studies show increased particulate matter (PM[Formula: see text]) particles in ambient air are correlated with increased myocardial infarctions. Given the close association of capillaries and alveoli, the dysfunction is caused when inhaled PM[Formula: see text] particles come in close proximity to capillary endothelial cells. We previously suggested that the inhalation of PM[Formula: see text] diesel exhaust particles (DEP) induces oxidative stress and upregulates the Nrf2/HO-1 pathway, inducing vascular permeability factor VEGFA secretion, which results in cell-cell adherens junction disruption and PM[Formula: see text] transmigratation into circulation. Here, we minimized the level that PM[Formula: see text] traveled in the bloodstream by pre-supplementing with a traditional Chinese medicine (TCM) Ganoderma tsugae DMSO extract (GTDE) prior to PM[Formula: see text] exposure. Our results show that PM[Formula: see text] caused alterations in enzyme activities and cellular anti-oxidant balance. We found decreased glutathione levels, a reduced cellular redox ratio, increased ROS generation and cytotoxicity in the cellular fractions. The oxidative stress caused DNA damage and apoptosis, likely causing downstream molecular events that trigger vasculature permeabilization and, eventually, cardiovascular disorders. Our results show long-term GTDE treatment increased endogenous glutathione level, while PM[Formula: see text]-reduced glutathione levels and the cellular redox ratio. GTDE was protective against the genotoxic and apoptotic effects initiated by PM[Formula: see text] oxidative stress. Vascular permeability revealed that PM[Formula: see text] only accumulated on the surface of cells after GTDE treatment; no penetration was detected. After two weeks of GTDE treatment, VEGFA secretion was significantly reduced in human umbilical vein endothelial cells (HUVEC) and endothelial cell migration was blocked. Our results suggest GTDE prevents PM[Formula: see text] transmigration into the bloodstream, and the resultant dysfunction, by inhibiting oxidative stress production and endothelial permeability. PMID:27080945

  12. Multielemental analysis of tree rings: a survey of coniferous trees in the Great Smoky Mountains National Park. [Picea rubens; Abies fraseri; Tsuga canadensis; Pinus rigida; Pinus strobus

    SciTech Connect

    Baes, C.F. III; McLaughlin, S.B.

    1986-01-01

    Conifers were sampled at various locations in the Great Smoky Mountains National Park (GSMNP) to examine changes in growth rate and elemental composition of the tree rings as a function of tree species and location. Earlier studies in the park had indicated (1) recent increases in deposition of trace metals at high-elevation sites and (2) decreased tree ring widths and increased iron accumulation in short-leaf pine between 1863 and 1912 in trees at Cades Cove, which were thought to be influenced by emissions from copper smelters at Copperhill, Tennessee, 88 km upwind of the cove. Conifers were cored for multielement analysis growth analysis at nine locations throughout the GSMNP. Multielement analysis was performed for 31 elements, 21 of which were generally detected in the xylem: Al, B, Ba, Be, Ca, Cd, Cu, Fe, Hf, K, Li, Mg, Mn, Na, Ni, P, Pb, Si, Sr, Ti, and Zn. There was little evidence of a synchronous growth decline in conifers between 1863 and 1912 at the sites sampled. A comparison between raw ring widths averaged over the periods 1974 to 1983 and 1929 to 1958 showed that approximately 77, 83, and 88% of all red spruce, Fraser fir, and hemlock, respectively, had lower growth rates during the latter time period. The elemental concentrations found in wood suggest that the trees in the GSMNP are not exposed to levels of trace metals as high as are trees immediately downwind of smelters or fossil fuel plants. However, the patterns of Mn and Zn in Fraser fir at high-elevation sites and the temporal similarity between increases of Al, B, Cu, Fe, and Ni in wood and increases in fossil fuel emissions upwind of the GSMNP suggest that forests in the park are exposed to increasing levels of trace metal deposition or that trace metals are made more available for uptake by trees as a result of anthropogenic influences. 48 refs., 22 figs., 11 tabs.

  13. Pollen-tube growth rates in Collinsia heterophylla (Plantaginaceae): one-donor crosses reveal heritability but no effect on sporophytic-offspring fitness

    PubMed Central

    Lankinen, Åsa; Maad, Johanne; Armbruster, W. Scott

    2009-01-01

    Background and Aims Evolutionary change in response to natural selection will occur only if a trait confers a selective advantage and there is heritable variation. Positive connections between pollen traits and fitness have been found, but few studies of heritability have been conducted, and they have yielded conflicting results. To understand better the evolutionary significance of pollen competition and its potential role in sexual selection, the heritability of pollen tube-growth rate and the relationship between this trait and sporophytic offspring fitness were investigated in Collinsia heterophylla. Methods Because the question being asked was if female function benefited from obtaining genetically superior fathers by enhancing pollen competition, one-donor (per flower) crosses were used in order to exclude confounding effects of post-fertilization competition/allocation caused by multiple paternity. Each recipient plant was crossed with an average of five pollen donors. Pollen-tube growth rate and sporophytic traits were measured in both generations. Key Results Pollen-tube growth rate in vitro differed among donors, and the differences were correlated with in vivo growth rate averaged over two to four maternal plants. Pollen-tube growth rate showed significant narrow-sense heritability and evolvability in a father–offspring regression. However, this pollen trait did not correlate significantly with sporophytic-offspring fitness. Conclusions These results suggest that pollen-tube growth rate can respond to selection via male function. The data presented here do not provide any support for the hypothesis that intense pollen competition enhances maternal plant fitness through increased paternity by higher-quality sporophytic fathers, although this advantage cannot be ruled out. These data are, however, consistent with the hypothesis that pollen competition is itself selectively advantageous, through both male and female function, by reducing the genetic load among successful gametophytic fathers (pollen), and reducing inbreeding depression associated with self–pollination in plants with mix-mating systems. PMID:19202136

  14. 76 FR 42675 - Availability of an Environmental Assessment and Finding of No Significant Impact for a Biological...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-19

    ... biological control agent to reduce the severity of hemlock woolly adelgid (Adelges tsugae, HWA) infestations. On January 19, 2011, we published in the Federal Register (75 FR 28232-28233, Docket No. APHIS-2010... Significant Impact for a Biological Control Agent for Hemlock Woolly Adelgid AGENCY: Animal and Plant...

  15. Late Glacial-Holocene Pollen-Based Vegetation History from Pass Lake, Prince of Wales Island, Southeastern Alaska

    USGS Publications Warehouse

    Ager, Thomas A.; Rosenbaum, Joseph G.

    2009-01-01

    A radiocarbon-dated history of vegetation development since late Wisconsin deglaciation has been reconstructed from pollen evidence preserved in a sediment core from Pass Lake on Prince of Wales Island, southeastern Alaska. The shallow lake is in the south-central part of the island and occupies a low pass that was filled by glacial ice of local origin during the late Wisconsin glaciation. The oldest pollen assemblages indicate that pine woodland (Pinus contorta) had developed in the area by ~13,715 cal yr B.P. An abrupt decline in the pine population, coinciding with expansion of alder (Alnus) and ferns (mostly Polypodiaceae) began ~12,875 yr B.P., and may have been a response to colder, drier climates during the Younger Dryas climatic interval. Mountain hemlock (Tsuga mertensiana) began to colonize central Prince of Wales Island by ~11,920 yr B.P. and was soon followed by Sitka spruce (Picea sitchensis). Pollen of western hemlock (Tsuga heterophylla) began to appear in Pass Lake sediments soon after 11,200 yr B.P. The abundance of western hemlock pollen in the Pass Lake core during most of the Holocene appears to be the result of wind transport from trees growing at lower altitudes on the island. The late Holocene pollen record from Pass Lake is incomplete because of one or more unconformities, but the available record suggests that a vegetation change occurred during the late Holocene. Increases in pollen percentages of pine, cedar (probably yellow cedar, Chamaecyparis nootkatensis), and heaths (Ericales) suggest an expansion of muskeg vegetation occurred in the area during the late Holocene. This vegetation change may be related to the onset of cooler, wetter climates that began as early as ~3,774 yr B.P. in the region. This vegetation history provides the first radiocarbon-dated Late Glacial-Holocene terrestrial paleoecological framework for Prince of Wales Island. An analysis of magnetic properties of core sediments from Pass Lake suggests that unconformities caused by low lake levels may be detectable where fine-grained ferrimagnets are concentrated in peaty sediments.

  16. An endophytic Coniochaeta velutina producing broad spectrum antimycotics.

    PubMed

    Xie, Jie; Strobel, Gary A; Feng, Tao; Ren, Huishuang; Mends, Morgan T; Zhou, Zeyang; Geary, Brad

    2015-06-01

    An endophyte (PC27-5) was isolated from stem tissue of Western hemlock (Tsuga heterophylla) in a Pacific Northwest temperate rainforest. Phylogenetic analyses, based on ITS-5.8S rDNA and 18S rDNA sequence data, combined with cultural and morphological analysis showed that endophyte PC27-5 exhibited all characteristics of a fungus identical to Coniochaeta velutina. Furthermore, wide spectrum antimycotics were produced by this endophyte that were active against such plant pathogens as Sclerotinia sclerotiorum, Pythium ultimum, and Verticillium dahliae and lethal to Phythophthora cinnamomi, Pythium ultimum, and Phytophthora palmivora in plate tests. The bioactive components were purified through organic solvent extraction, followed by silica column chromatography, and finally preparative HPLC. The minimum inhibitory concentration of the active fraction to Pythium ultimum, which was gained from preparative HPLC, was 11 μg/ml. UPLC-HRMS analysis showed there were two similar components in the antimycotic fraction. Their molecular formulae were established as C30H22O11 (compound I) and C30H22O10 (compound II) respectively, and preliminary spectral results indicate that they are anthroquinone glycosides. Other non-biologically active compounds were identified in culture fluids of this fungus by spectral means as emodin and chrysophanol--anthroquinone derivatives. This is the first report that Coniochaeta velutina as an endophyte produces bioactive antifungal components. PMID:26025171

  17. Simulating secondary succession of elk forage values in a managed forest landscape, western Washington

    USGS Publications Warehouse

    Jenkins, Kurt J.; Starkey, Edward E.

    1996-01-01

    Modern timber management practices often influence forage production for elk (Cervus elaphus) on broad temporal and spatial scales in forested landscapes. We incorporated site-specific information on postharvesting forest succession and forage characteristics in a simulation model to evaluate past and future influences of forest management practices on forage values for elk in a commercially managed Douglas fir (Pseudotsuga menziesii, PSME)-western hemlock (Tsuga heterophylla, TSHE) forest in western Washington. We evaluated future effects of: (1) clear-cut logging 0, 20, and 40% of harvestable stands every five years; (2) thinning 20-year-old Douglas fir forests; and (3) reducing the harvesting cycle from 60 to 45 years. Reconstruction of historical patterns of vegetation succession indicated that forage values peaked in the 1960s and declined from the 1970s to the present, but recent values still were higher than may have existed in the unmanaged landscape in 1945. Increased forest harvesting rates had little short-term influence on forage trends because harvestable stands were scarce. Simulations of forest thinning also produced negligible benefits because thinning did not improve forage productivity appreciably at the stand level. Simulations of reduced harvesting cycles shortened the duration of declining forage values from approximately 30 to 15 years. We concluded that simulation models are useful tools for examining landscape responses of forage production to forest management strategies, but the options examined provided little potential for improving elk forages in the immediate future.

  18. Headwater riparian invertebrate communities associated with red alder and conifer wood and leaf litter in southeastern Alaska

    USGS Publications Warehouse

    LeSage, C.M.; Merritt, R.W.; Wipfli, M.S.

    2005-01-01

    We examined how management of young upland forests in southeastern Alaska affect riparian invertebrate taxa richness, density, and biomass, in turn, potentially influencing food abundance for fish and wildlife. Southeastern Alaska forests are dominated by coniferous trees including Sitka spruce (Picea sitchensis (Bong.) Carr.), western hemlock (Tsuga heterophylla (Raf.) Sarg.), with mixed stands of red cedar (Thuja plicata Donn.). Red alder (Alnus rubra Bong.) is hypothesized to influence the productivity of young-growth conifer forests and through forest management may provide increased riparian invertebrate abundance. To compare and contrast invertebrate densities between coniferous and alder riparian habitats, leaf litter and wood debris (early and late decay classes) samples were collected along eleven headwater streams on Prince of Wales Island, Alaska, during the summers of 2000 and 2001. Members of Acarina and Collembola were the most abundant taxa collected in leaf litter with alder litter having significantly higher mean taxa richness than conifer litter. Members of Acarina were the most abundant group collected on wood debris and alder wood had significantly higher mean taxa richness and biomass than conifer wood. Alder wood debris in more advanced decay stages had the highest mean taxa richness and biomass, compared to other wood types, while conifer late decay wood debris had the highest densities of invertebrates. The inclusion of alder in young-growth conifer forests can benefit forest ecosystems by enhancing taxa richness and biomass of riparian forest invertebrates. ?? 2005 by the Northwest Scientific Association. All rights reserved.

  19. Development and testing of a snow interceptometer to quantify canopy water storage and interception processes in the rain/snow transition zone of the North Cascades, Washington, USA

    NASA Astrophysics Data System (ADS)

    Martin, Kael A.; Stan, John T.; Dickerson-Lange, Susan E.; Lutz, James A.; Berman, Jeffrey W.; Gersonde, Rolf; Lundquist, Jessica D.

    2013-06-01

    Tree canopy snow interception is a significant hydrological process, capable of removing up to 60% of snow from the ground snowpack. Our understanding of canopy interception has been limited by our ability to measure whole canopy water storage in an undisturbed forest setting. This study presents a relatively inexpensive technique for directly measuring snow canopy water storage using an interceptometer, adapted from Friesen et al. (2008). The interceptometer is composed of four linear motion position sensors distributed evenly around the tree trunk. We incorporate a trunk laser-mapping installation method for precise sensor placement to reduce signal error due to sensor misalignment. Through calibration techniques, the amount of canopy snow required to produce the measured displacements can be calculated. We demonstrate instrument performance on a western hemlock (Tsuga heterophylla) for a snow interception event in November 2011. We find a snow capture efficiency of 83 ± 15% of accumulated ground snowfall with a maximum storage capacity of 50 ± 8 mm snow water equivalent (SWE). The observed interception event is compared to simulated interception, represented by the variable infiltration capacity (VIC) hydrologic model. The model generally underreported interception magnitude by 33% using a leaf area index (LAI) of 5 and 16% using an LAI of 10. The interceptometer captured intrastorm accumulation and melt rates up to 3 and 0.75 mm SWE h-1, respectively, which the model failed to represent. While further implementation and validation is necessary, our preliminary results indicate that forest interception magnitude may be underestimated in maritime areas.

  20. Distribution and dynamics of two ferns: Dennstaedtia punctilobula (Dennstaedtiaceae) and Thelypteris noveboracensis (Thelypteridaceae) in a Northeast mixed hardwoods-hemlock forest.

    PubMed

    Hill, J D; Silander, J A

    2001-05-01

    Dennstaedtia punctilobula and Thelypteris noveboracensis are two native species that often arrest forest succession and reduce understory diversity. As part of a project to examine the feedback between forest understory and canopy dynamics, we studied the patterns of distribution and dynamics of these two fern species in an oak-transition hardwoods-hemlock forest. Dennstaedtia was least abundant under shade-tolerant tree species and most abundant in small (1-2 trees) canopy gaps, but did not show any distinct patterns across the sampled moisture regime. The light response was verified using light manipulation experiments and examination of plant size-abundance patterns across light environments. Thelypteris tended to be most prevalent under maple canopies and appeared to be more sensitive to soil moisture regime being restricted to more mesic sites than Dennstaedtia. Seasonal and year-to-year changes in abundance of established clones of both fern species were small, suggesting that once established, both species can maintain a strong hold on a site. Further work on the niche requirements of the two species is warranted, but any event that maintains or promotes canopy openness (tree death by disease or windthrow, forest harvesting, or the elimination of a shrub layer by browsing) will promote persistence of Dennstaedtia. PMID:11353714

  1. Euphorbia heterophylla leaf extract mediated green synthesis of Ag/TiO2 nanocomposite and investigation of its excellent catalytic activity for reduction of variety of dyes in water.

    PubMed

    Atarod, Monireh; Nasrollahzadeh, Mahmoud; Mohammad Sajadi, S

    2016-01-15

    This work reports a facile and green synthesis of Ag/TiO2 nanocomposite by extract of leaves of Euphorbia heterophylla without any stabilizer or surfactant. The green synthesized Ag/TiO2 nanocomposite was characterized by field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDS), fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction analysis (XRD) and UV-vis. The Ag/TiO2 nanocomposite was found to be effective catalyst for reduction of various dyes, such as 4-nitrophenol (4-NP), Methyl orange (MO), Congo red (CR) and Methylene blue (MB) in the presence of NaBH4 in water at room temperature. Catalysis reactions were monitored by employing UV-vis spectroscopy. Catalysis reactions followed pseudo-first order rate equation. The catalyst can be recovered and reused several times without significant loss of its catalytic activity. PMID:26469545

  2. A High Resolution Late Holocene Paleo-atmospheric Co2 Reconstruction From Stomatal Frequency Analysis of Conifer Needles

    NASA Astrophysics Data System (ADS)

    Kouwenberg, L. L. R.; Kurschner, W. M.; Wagner, F.; Visscher, H.

    An inverse relation of stomatal frequency in leaves of many plant taxa and atmospheric CO2 concentration has been repeatedly demonstrated. Response curves based on this species-specific relation are increasingly used to reconstruct paleo-CO2 levels from stomatal frequency analysis on fossil leaves. This type of atmospheric CO2 records have been produced for a large part of geological history, varying from the Paleozoic to the Holocene. Quaternary glaciochemical records from Antarctica and Greenland suggest that CO2 concentration and temperature are strongly linked, in general CO2 appears to lag temperature change. However, in order to assess this relation, high res- olution records with a precise chronology are needed. During the Holocene, several century-scale climatic fluctuations took place, such as the 8.2 kyr event and the Lit- tle Ice age. Linking these temperature fluctuations to paleo-CO2 concentrations in glaciochemical records can be difficult, because the resolution of ice-cores is gen- erally low and the ice-gas age difference complicates accurate dating. An excellent alternative tool for high-resolution Holocene CO2 reconstructions can be provided by stomatal frequency analysis of leaves from Holocene peat and lake sediments. In this study, it is demonstrated that the western hemlock (Tsuga heterophylla) also ad- justs its stomatal frequency to the historical CO2 rise. After careful proxy-validation, a high resolution paleo-atmospheric CO2 record over the last 2000 years based on subfossil Tsuga heterophylla needles from Mount Rainier (Washington, USA) was re- constructed. Chronology is provided by a suite of AMS carbon isotope dates and the presence of tephra layers from nearby Mt. St Helens. The record reproduces CO2 lev- els around 280 ppmv for the Little Ice Age and the CO2 rise to 365 ppmv over the last 150 years. A prominent feature is a marked rise in CO2 at 350 years AD, gradu- ally declining over the next centuries. The CO2 record will be discussed in terms of its relation to local volcanic CO2 production, paleoclimate data and changes in the terrestrial and marine carbon sources and sinks.

  3. Ganoderma tsugae Induces S Phase Arrest and Apoptosis in Doxorubicin-Resistant Lung Adenocarcinoma H23/0.3 Cells via Modulation of the PI3K/Akt Signaling Pathway

    PubMed Central

    Yu, Yang-Hao; Kuo, Han-Peng; Hsieh, Hui-Hsia; Li, Jhy-Wei; Hsu, Wu-Huei; Chen, Shih-Jung; Su, Muh-Hwan; Liu, Shwu-Huey; Cheng, Yung-Chi; Chen, Chih-Yi; Kao, Ming-Ching

    2012-01-01

    Ganoderma tsugae (GT) is a traditional Chinese medicine that exhibits significant antitumor activities against many types of cancer. This study investigated the molecular mechanism by which GT suppresses the growth of doxorubicin-resistant lung adenocarcinoma H23/0.3 cells. Our results reveal that GT inhibits the viability of H23/0.3 cells in vitro and in vivo and sensitizes the growth suppression effect of doxorubicin on H23/0.3 cells. The data also show that GT induces S phase arrest by interfering with the protein expression of cyclin A, cyclin E, CDK2, and CDC25A. Furthermore, GT induces cellular apoptosis via induction of a mitochondria/caspase pathway. In addition, we also demonstrate that the suppression of cell proliferation by GT is through down-regulation of the PI3K/Akt signaling pathway. In conclusion, this study suggests that GT may be a useful adjuvant therapeutic agent in the treatment of lung cancer. PMID:22792123

  4. ACID FOG EFFECTS ON CONIFER SEEDLINGS

    EPA Science Inventory

    Experiments were performed to assess the effects of acid fog on foliar injury, biomass production, and nutrient leaching in selected conifers. ne-year old seedlings of Pseudotsuga menzieii, Pinus ponderosa, Tsuga heterophylla and Thuja plicata were exposed episodically to fog eve...

  5. The Importance of Large-Diameter Trees to Forest Structural Heterogeneity

    PubMed Central

    Lutz, James A.; Larson, Andrew J.; Freund, James A.; Swanson, Mark E.; Bible, Kenneth J.

    2013-01-01

    Large-diameter trees dominate the structure, dynamics and function of many temperate and tropical forests. However, their attendant contributions to forest heterogeneity are rarely addressed. We established the Wind River Forest Dynamics Plot, a 25.6 ha permanent plot within which we tagged and mapped all 30,973 woody stems ≥1 cm dbh, all 1,966 snags ≥10 cm dbh, and all shrub patches ≥2 m2. Basal area of the 26 woody species was 62.18 m2/ha, of which 61.60 m2/ha was trees and 0.58 m2/ha was tall shrubs. Large-diameter trees (≥100 cm dbh) comprised 1.5% of stems, 31.8% of basal area, and 17.6% of the heterogeneity of basal area, with basal area dominated by Tsuga heterophylla and Pseudotsuga menziesii. Small-diameter subpopulations of Pseudotsuga menziesii, Tsuga heterophylla and Thuja plicata, as well as all tree species combined, exhibited significant aggregation relative to the null model of complete spatial randomness (CSR) up to 9 m (P≤0.001). Patterns of large-diameter trees were either not different from CSR (Tsuga heterophylla), or exhibited slight aggregation (Pseudotsuga menziesii and Thuja plicata). Significant spatial repulsion between large-diameter and small-diameter Tsuga heterophylla suggests that large-diameter Tsuga heterophylla function as organizers of tree demography over decadal timescales through competitive interactions. Comparison among two forest dynamics plots suggests that forest structural diversity responds to intermediate-scale environmental heterogeneity and disturbances, similar to hypotheses about patterns of species richness, and richness- ecosystem function. Large mapped plots with detailed within-plot environmental spatial covariates will be required to test these hypotheses. PMID:24376579

  6. Flux partitioning in an old-growth forest: seasonal and interannual dynamics.

    PubMed

    Falk, Matthias; Wharton, Sonia; Schroeder, Matt; Ustin, Susan; Paw U, Kyaw Tha

    2008-04-01

    Turbulent fluxes of carbon, water and energy were measured at the Wind River Canopy Crane, Washington, USA from 1999 to 2004 with eddy-covariance instrumentation above (67 m) and below (2.5 m) the forest canopy. Here we present the decomposition of net ecosystem exchange of carbon (NEE) into gross primary productivity (GPP), ecosystem respiration (R(eco)) and tree canopy net CO(2) exchange (DeltaC) for an old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)-western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest. Significant amounts of carbon were recycled within the canopy because carbon flux measured at the below-canopy level was always upward. Maximum fluxes reached 4-6 micromol m(-2) s(-1) of CO(2) into the canopy air space during the summer months, often equaling the net downward fluxes measured at the above-canopy level. Ecosystem respiration rates deviated from the expected exponential relationship with temperature during the summer months. An empirical ecosystem stress term was derived from soil water content and understory flux data and was added to the R(eco) model to account for attenuated respiration during the summer drought. This attenuation term was not needed in 1999, a wet La Niña year. Years in which climate approximated the historical mean, were within the normal range in both NEE and R(eco), but enhanced or suppressed R(eco) had a significant influence on the carbon balance of the entire stand. In years with low respiration the forest acts as a strong carbon sink (-217 g C m(-2) year(-1)), whereas years in which respiration is high can turn the ecosystem into a weak to moderate carbon source (+100 g C m(-2) year(-1)). PMID:18244938

  7. Characterization of an Endophytic Gloeosporium sp. and Its Novel Bioactivity with "Synergistans".

    PubMed

    Schaible, George A; Strobel, Gary A; Mends, Morgan Tess; Geary, Brad; Sears, Joe

    2015-07-01

    Gloeosporium sp. (OR-10) was isolated as an endophyte of Tsuga heterophylla (Western hemlock). Both ITS and 18S sequence analyses indicated that the organism best fits either Hypocrea spp. or Trichoderma spp., but neither of these organisms possess conidiophores associated with acervuli, in which case the endophytic isolate OR-10 does. Therefore, the preferred taxonomic assignment was primarily based on the morphological features of the organism as one belonging to the genus Gloeosporium sp. These taxonomic observations clearly point out that limited ITS and 18S sequence information can be misleading when solely used in making taxonomic assignments. The volatile phase of this endophyte was active against a number of plant pathogenic fungi including Phytophthora palmivora, Rhizoctonia solani, Ceratocystis ulmi, Botrytis cinerea, and Verticillium dahliae. Among several terpenes and furans, the most abundantly produced compound in the volatile phase was 6-pentyl-2H-pyran-2-one, a compound possessing antimicrobial activities. When used in conjunction with microliter amounts of any in a series of esters or isobutyric acid, an enhanced inhibitory response occurred with each test fungus that was greater than that exhibited by Gloeosporium sp. or the compounds tested individually. Compounds behaving in this manner are hereby designated "synergistans." An expression of the "median synergistic effect," under prescribed conditions, has been termed the mSE50. This value describes the amount of a potential synergistan that is required to yield an additional median 50% inhibition of a target organism. In this report, the mSE50s are reported for a series of esters and isobutyric acid. The results indicated that isoamyl acetate, allyl acetate, and isobutyric acid generally possessed the lowest mSE50 values. The value and potential importance of these microbial synergistic effects to the microbial environment are also discussed. PMID:25501886

  8. Diversity of Riparian Plants among and within Species Shapes River Communities

    PubMed Central

    Jackrel, Sara L.; Wootton, J. Timothy

    2015-01-01

    Organismal diversity among and within species may affect ecosystem function with effects transmitting across ecosystem boundaries. Whether recipient communities adjust their composition, in turn, to maximize their function in response to changes in donor composition at these two scales of diversity is unknown. We use small stream communities that rely on riparian subsidies as a model system. We used leaf pack experiments to ask how variation in plants growing beside streams in the Olympic Peninsula of Washington State, USA affects stream communities via leaf subsidies. Leaves from red alder (Alnus rubra), vine maple (Acer cinereus), bigleaf maple (Acer macrophyllum) and western hemlock (Tsuga heterophylla) were assembled in leaf packs to contrast low versus high diversity, and deployed in streams to compare local versus non-local leaf sources at the among and within species scales. Leaves from individuals within species decomposed at varying rates; most notably thin leaves decomposed rapidly. Among deciduous species, vine maple decomposed most rapidly, harbored the least algal abundance, and supported the greatest diversity of aquatic invertebrates, while bigleaf maple was at the opposite extreme for these three metrics. Recipient communities decomposed leaves from local species rapidly: leaves from early successional plants decomposed rapidly in stream reaches surrounded by early successional forest and leaves from later successional plants decomposed rapidly adjacent to later successional forest. The species diversity of leaves inconsistently affected decomposition, algal abundance and invertebrate metrics. Intraspecific diversity of leaf packs also did not affect decomposition or invertebrate diversity. However, locally sourced alder leaves decomposed more rapidly and harbored greater levels of algae than leaves sourced from conspecifics growing in other areas on the Olympic Peninsula, but did not harbor greater aquatic invertebrate diversity. In contrast to alder, local intraspecific differences via decomposition, algal or invertebrate metrics were not observed consistently among maples. These results emphasize that biodiversity of riparian subsidies at the within and across species scale have the potential to affect aquatic ecosystems, although there are complex species-specific effects. PMID:26539714

  9. Coast Range Ecoregion: Chapter 1 in Status and trends of land change in the Western United States--1973 to 2000

    USGS Publications Warehouse

    Sohl, Terry L.

    2012-01-01

    The Coast Range Ecoregion, which covers approximately 57,338 km2 (22,138 mi2), is a thin, linear ecoregion along the Pacific Coast, stretching roughly 1,300 km from the Olympic Peninsula, in northwest Washington, to an area south of San Francisco, California (fig. 1) (Omernik, 1987; U.S. Environmental Protection Agency, 1997). It is bounded on the east by the Puget Lowland, the Willamette Valley, the Klamath Mountains, and the Southern and Central California Chaparral and Oak Woodlands Ecoregions. Almost the entire Coast Range Ecoregion lies within 100 km of the coast. Topography is highly variable, with coastal mountain ranges and valleys ranging from sea level to over 1,000 m in elevation (fig. 2). A maritime climate, along with high topographic relief, results in substantial, but regionally variable, amounts of rainfall, ranging from 130 cm to more than 350 cm per year. The favorable climate of the Coast Range Ecoregion has supported forests of Sitka spruce (Picea sitchensis) along its northern coast and coast redwoods (Sequoia sempervirens) along its southern coast, as well as Douglas-fir (Pseudotsuga menziesii), western red cedar (Thuja plicata), and western hemlock (Tsuga heterophylla) inland (Omernik, 1987). Today, however, much of the forest is heavily managed for logging (fig. 3), although the ecoregion still supports some of the largest remaining areas of old-growth forest in the Pacific Northwest. Agriculture is a minor component of the landscape, present locally in flat lands and valleys near the coast. Urban development is minimal; Eureka, California, is the only urban center in the ecoregion, with a population of over 26,000 (U.S. Census Bureau, 2000).

  10. Diversity of Riparian Plants among and within Species Shapes River Communities.

    PubMed

    Jackrel, Sara L; Wootton, J Timothy

    2015-01-01

    Organismal diversity among and within species may affect ecosystem function with effects transmitting across ecosystem boundaries. Whether recipient communities adjust their composition, in turn, to maximize their function in response to changes in donor composition at these two scales of diversity is unknown. We use small stream communities that rely on riparian subsidies as a model system. We used leaf pack experiments to ask how variation in plants growing beside streams in the Olympic Peninsula of Washington State, USA affects stream communities via leaf subsidies. Leaves from red alder (Alnus rubra), vine maple (Acer cinereus), bigleaf maple (Acer macrophyllum) and western hemlock (Tsuga heterophylla) were assembled in leaf packs to contrast low versus high diversity, and deployed in streams to compare local versus non-local leaf sources at the among and within species scales. Leaves from individuals within species decomposed at varying rates; most notably thin leaves decomposed rapidly. Among deciduous species, vine maple decomposed most rapidly, harbored the least algal abundance, and supported the greatest diversity of aquatic invertebrates, while bigleaf maple was at the opposite extreme for these three metrics. Recipient communities decomposed leaves from local species rapidly: leaves from early successional plants decomposed rapidly in stream reaches surrounded by early successional forest and leaves from later successional plants decomposed rapidly adjacent to later successional forest. The species diversity of leaves inconsistently affected decomposition, algal abundance and invertebrate metrics. Intraspecific diversity of leaf packs also did not affect decomposition or invertebrate diversity. However, locally sourced alder leaves decomposed more rapidly and harbored greater levels of algae than leaves sourced from conspecifics growing in other areas on the Olympic Peninsula, but did not harbor greater aquatic invertebrate diversity. In contrast to alder, local intraspecific differences via decomposition, algal or invertebrate metrics were not observed consistently among maples. These results emphasize that biodiversity of riparian subsidies at the within and across species scale have the potential to affect aquatic ecosystems, although there are complex species-specific effects. PMID:26539714

  11. 49. Perspective view of the east facade of the mansion ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. Perspective view of the east facade of the mansion and the east lawn, from the northeast. The view includes manicured hemlock (Tsuga canadensis), an annual flower bed, white pine (Pinus strobus), white birch (Betula species), and Norway spruce (Picea abies). - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  12. 51. View from the east entry door of the mansion ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. View from the east entry door of the mansion across the veranda and the big meadow of the Billings Farm & Museum, to Blake Hill. The view includes manicured hemlock (Tsuga canadensis), and white pine (Pinus strobus). - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  13. 8. View from the east entry door of the mansion ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. View from the east entry door of the mansion across the veranda and the big meadow of the Billings Farm & Museum, to Blake Hill. The view includes manicured hemlock (Tsuga canadensis), and white pine (Pinus strobus). - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  14. 4. Perspective view of the east facade of the mansion ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Perspective view of the east facade of the mansion and the east lawn, from the northeast (more distant view). The view includes manicured hemlock (Tsuga canadensis), an annual flower bed, white pine (Pinus strobus) and white birch (Betula species). - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  15. 6. Perspective view of the south facade of the mansion ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Perspective view of the south facade of the mansion and the south lawn, from the southeast. (more distant view). The view includes manicured hemlock (Tsuga canadensis), an annual flower bed, white pine (Pinus strobus) and white birch (Betula species). - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  16. 5. Perspective view of the east facade of the mansion ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Perspective view of the east facade of the mansion and the east lawn, from the northeast (less distant view). The view includes manicured hemlock (Tsuga canadensis), an annual flower bed, white pine (Pinus strobus), white birch (Betula species), and Norway spruce (Picea abies). - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  17. 1. View of rustic summer houses at pedestrian pathway entrance ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. View of rustic summer houses at pedestrian pathway entrance to the southern edge of the mansion grounds. The view illustrates significant grade change and includes rustic stone retaining walls, recently re-planted hemlock hedge (Tsuga canadensis), and canopy of mature Norway spruces (Picea abies). - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  18. 50. Perspective view of the south facade of the mansion ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    50. Perspective view of the south facade of the mansion and the south lawn, from the southeast. The view includes foundation and lawn plantings of wingbark euonymous (Euonymous alatus compactus), Japanese yew (Taxus cuspidata nana), manicured hemlock (Tsuga canadensis), and a white pine (Pinus strobus). - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  19. 7. Perspective view of the south facade of the mansion ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Perspective view of the south facade of the mansion and the south lawn, from the southwest. The view includes foundation and lawn plantings of wingbark euonymus (Euonymus fortunei vegetis), Japanese yew (Taxus cuspidata nana), manicured hemlock (Tsuga canadensis), and white pine (Pinus strobus). - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  20. A 26,600 yr record of climate and vegetation from Rice Lake in the Eel River drainage of the northern California Coast Range

    NASA Astrophysics Data System (ADS)

    Heusser, L. E.

    2014-12-01

    Rice Lake, (40'41" N; 123'30" W, 1109 m elev.) lies in the transition zone of the precipitation dipole in the western United States, which is reflected by the present vegetation - a mosaic of mesic northern mixed hardwood-evergreen forests (Quercus spp., Pinus spp., Calocedrus/Juniperus) and more arid southern oak foothill woodlands (Quercus spp.) that borders the westernmost edge of coastal redwoods (Sequoia sempervirens) forest. The site, which lies on the active Lake Mountain fault zone, is now a large (~15 ha) sagpond that dries in summer. Between ~26,600 yr - ~15,000 yr, a permanent lake with aquatic vegetation (Isoetes) occupied the core site. Montane conifer forests, with pine (Pinus, spp.), mountain hemlock (Tsuga mertensiana), spruce (Picea spp), and western hemlock (T. heterophylla) covered the region. Climatic parameters of modern montane coniferous forest and the continued presence of aquatic vegetation (Isoetes) suggest higher precipitation and lower temperatures during the last glacial. Charcoal (fire event frequency) was minimal. Rapid oscillations of oak, the riparian alder (Alnus), pine, Cupressaceae (Juniperus, Calocedrus), Douglas fir (Pseudotsuga menzeii), and fir (Abies) characterize the deglacial, and reflect rapid changes in precipitation and temperatures, e.g, Bølling-Allerød warming and Younger Dryas cooling. Between ~15,000 yr and ~13,000 yr, aquatic vegetation of the lake abruptly decreased. Expansion of oak, tanoak (Lithocarpus), shrubs (cf. Ceanothus) and decline of pine and montane conifers, along with the development of marshes with Typha and Cyperaceae on the former lakebed, imply early Holocene warming and decreasing precipitation. This is supported by an increase in charcoal, which is attributed to forest fires. Between ~5,000 yr - ~6,000 yr, a short interval of increased precipitation (inferred from a peak in alder and decrease in Cupressaceae) initiates the development of modern mixed hardwood-evergreen forest. Correlative data from terrestrial and marine climate proxies from a core located 33 km off the mouth of the Eel River, (TN062 0550, 40.9°N, 124.6°W, 569 m water depth) suggest that ENSO-like conditions typified the Holocene.

  1. 2. View from the mansion formal entrance driveway toward the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. View from the mansion formal entrance driveway toward the big meadow at the Billings Farm & Museum. The driveway is flanked by granite gateposts surmounted by wrought iron urn lamps. The view includes a manicured hemlock hedge (Tsuga canadensis) retained by a stone wall at left, and white birch (Betula species) under-planted with ferns at center. - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  2. Dynamic variation in sapwood specific conductivity in six woody species.

    PubMed

    Domec, Jean-Christophe; Meinzer, Frederick C; Lachenbruch, Barbara; Housset, Johann

    2007-10-01

    Our goals were to quantify how non-embolism-inducing pressure gradients influence trunk sapwood specific conductivity (k(s)) and to compare the impacts of constant and varying pressure gradients on k(s) with KCl and H2O as the perfusion solutions. We studied six woody species (three conifers and three angiosperms) which varied in pit membrane structure, pit size and frequency of axial water transport across pits (long versus short conduits). Both stepwise ("steady") and nonlinear continuous ("non-steady") decreases in the pressure gradient led to decreased k(s) in all species but white oak (Quercus garryana Dougl. ex Hook), a ring-porous and long-vesseled angiosperm. In one diffuse-porous angiosperm (red alder, Alnus rubra Bong.) and two conifers (western red cedar, Thuja plicata Donn. ex D. Don, and Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco), k(s) was 10-30% higher under steady pressure gradients than under non-steady pressure gradients, and a decrease in the pressure gradient from 0.15 to 0.01 MPa m(-1) caused a 20-42% decrease in k(s). In another diffuse-porous angiosperm (maple, Acer macrophyllum Pursh) and in a third coniferous species (western hemlock, Tsuga heterophylla (Raf.) Sarg), there was no difference between k(s) measured under steady and non-steady pressure gradients. With the exception of western red cedar, a conifer with simple pit membranes, the differences in k(s) between low and high pressure gradients tended to be lower in the conifers than in the diffuse-porous angiosperms. In Douglas-fir, western red cedar and the diffuse-porous angiosperms, k(s) was higher when measured with KCl than with H2O. In white oak, there were no differences in k(s) whether measured under steady or non-steady pressure gradients, or when xylem was perfused with KCl or H2O. The species differences in the behavior of k(s) suggest that elasticity of the pit membrane was the main factor causing k(s) to be disproportionate to the pressure gradient and to the different pressure regimes. The results imply that, if nonlinearities in pressure-flux relationships are ignored when modeling tree water relations in vivo, large errors will result in the predictions of tree water status and its impact on stomatal control of transpiration and photosynthesis. PMID:17669729

  3. Influences of Forest Tree Species and Early Spring Temperature on Surface-Atmosphere Transfers of Water and Carbon in the Northeastern U.S.

    NASA Astrophysics Data System (ADS)

    Hadley, J. L.; Kuzeja, P.; Mulcahy, T.; Singh, S.

    2008-12-01

    Influences of Forest Tree Species and Early Spring Temperature on Surface-Atmosphere Transfers of Water and Carbon in the Northeastern U.S. Julian Hadley, Paul Kuzeja, Safina Singh and Thomas Mulcahy Transfers of water vapor from terrestrial ecosystems to the atmosphere affect regional hydrology, weather and climate over short time scales, and forest-atmosphere CO2 exchange affects global climate over long timescales. To better understand these effects for forests dominated by two very different tree species, we measured forest-atmosphere water vapor and CO2 transfers by the eddy flux technique to at two sites in central Massachusetts USA for three years. Average annual evapotranspiration (ET) for a young deciduous forest dominated by red oak (Quercus rubra L., the most abundant tree species in the area), was about 430 mm or 25 percent greater than for a coniferous forest dominated by 100 to 230 year old eastern hemlock (Tsuga canadensis L.). The difference in ET was most pronounced in July and August when the deciduous forest lost about 50 percent more water by ET in the average year (192 mm for oak forest versus 130 mm for hemlock). These data indicate that if deciduous trees with similar physiology to red oak replace hemlocks, summertime ET will increase while summer streamflow, soil water content and the extent of year- round wetlands will decrease. Increased summertime ET should also lead to slightly higher regional atmospheric humidity and precipitation. Hemlock-to-deciduous forest conversion has occurred from North Carolina to southern New England and is continuing northward as a lethal insect pest, the hemlock woolly adelgid (Adelges tsugae Annand) continues to kill hemlocks. Average annual carbon storage for the old hemlock forest in our study was about 3.3 Mg C/ha, nearly equal to the average for the deciduous forest, 3.5 Mg C/ha. This calls into question ecological theory that predicts large declines in the rate of carbon uptake for old forests, and indicates that annual carbon storage will not necessarily increase over the long term after hemlock trees are killed by the hemlock woolly adelgid and replaced by deciduous species. Maximum monthly carbon storage in the hemlock forest occurred in spring (April and May) and was enhanced by early soil thawing and cessation of nighttime frost. This pattern is probably common to many evergreen conifers in the northeastern U.S., so climate warming that includes an earlier end to freezing temperatures in spring should increase C storage by conifer forests in the northeastern U.S. - unless this effect is canceled out by reduced C uptake or enhanced C loss due to changes in summer and fall climate.

  4. Structural and compositional controls on transpiration in 40- and 450-year-old riparian forests in western Oregon, USA.

    PubMed

    Moore, Georgianne W; Bond, Barbara J; Jones, Julia A; Phillips, Nathan; Meinzer, Federick C

    2004-05-01

    Large areas of forests in the Pacific Northwest are being transformed to younger forests, yet little is known about the impact this may have on hydrological cycles. Previous work suggests that old trees use less water per unit leaf area or sapwood area than young mature trees of the same species in similar environments. Do old forests, therefore, use less water than young mature forests in similar environments, or are there other structural or compositional components in the forests that compensate for tree-level differences? We investigated the impacts of tree age, species composition and sapwood basal area on stand-level transpiration in adjacent watersheds at the H.J. Andrews Forest in the western Cascades of Oregon, one containing a young, mature (about 40 years since disturbance) conifer forest and the other an old growth (about 450 years since disturbance) forest. Sap flow measurements were used to evaluate the degree to which differences in age and species composition affect water use. Stand sapwood basal area was evaluated based on a vegetation survey for species, basal area and sapwood basal area in the riparian area of two watersheds. A simple scaling exercise derived from estimated differences in water use as a result of differences in age, species composition and stand sapwood area was used to estimate transpiration from late June through October within the entire riparian area of these watersheds. Transpiration was higher in the young stand because of greater sap flux density (sap flow per unit sapwood area) by age class and species, and greater total stand sapwood area. During the measurement period, mean daily sap flux density was 2.30 times higher in young compared with old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. Sap flux density was 1.41 times higher in young red alder (Alnus rubra Bong.) compared with young P. menziesii trees, and was 1.45 times higher in old P. menziesii compared with old western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees. Overall, sapwood basal area was 21% higher in the young stand than in the old stand. In the old forest, T. heterophylla is an important co-dominant, accounting for 58% of total sapwood basal area, whereas P. menziesii is the only dominant conifer in the young stand. Angiosperms accounted for 36% of total sapwood basal area in the young stand, but only 7% in the old stand. For all factors combined, we estimated 3.27 times more water use by vegetation in the riparian area of the young stand over the measurement period. Tree age had the greatest effect on stand differences in water use, followed by differences in sapwood basal area, and finally species composition. The large differences in transpiration provide further evidence that forest management alters site water balance via elevated transpiration in vigorous young stands. PMID:14996653

  5. Foundation species loss affects vegetation structure more than ecosystem function in a northeastern USA forest

    PubMed Central

    Orwig, David A.; Barker Plotkin, Audrey A.; Davidson, Eric A.; Lux, Heidi; Savage, Kathleen E.

    2013-01-01

    Loss of foundation tree species rapidly alters ecological processes in forested ecosystems. Tsuga canadensis, an hypothesized foundation species of eastern North American forests, is declining throughout much of its range due to infestation by the nonnative insect Adelges tsugae and by removal through pre-emptive salvage logging. In replicate 0.81-ha plots, T. canadensis was cut and removed, or killed in place by girdling to simulate adelgid damage. Control plots included undisturbed hemlock and mid-successional hardwood stands that represent expected forest composition in 50–100 years. Vegetation richness, understory vegetation cover, soil carbon flux, and nitrogen cycling were measured for two years prior to, and five years following, application of experimental treatments. Litterfall and coarse woody debris (CWD), including snags, stumps, and fallen logs and branches, have been measured since treatments were applied. Overstory basal area was reduced 60%–70% in girdled and logged plots. Mean cover and richness did not change in hardwood or hemlock control plots but increased rapidly in girdled and logged plots. Following logging, litterfall immediately decreased then slowly increased, whereas in girdled plots, there was a short pulse of hemlock litterfall as trees died. CWD volume remained relatively constant throughout but was 3–4× higher in logged plots. Logging and girdling resulted in small, short-term changes in ecosystem dynamics due to rapid regrowth of vegetation but in general, interannual variability exceeded differences among treatments. Soil carbon flux in girdled plots showed the strongest response: 35% lower than controls after three years and slowly increasing thereafter. Ammonium availability increased immediately after logging and two years after girdling, due to increased light and soil temperatures and nutrient pulses from leaf-fall and reduced uptake following tree death. The results from this study illuminate ecological processes underlying patterns observed consistently in region-wide studies of adelgid-infested hemlock stands. Mechanisms of T. canadensis loss determine rates, magnitudes, and trajectories of ecological changes in hemlock forests. Logging causes abrupt, large changes in vegetation structure whereas girdling (and by inference, A. tsugae) causes sustained, smaller changes. Ecosystem processes depend more on vegetation cover per se than on species composition. We conclude that the loss of this late-successional foundation species will have long-lasting impacts on forest structure but subtle impacts on ecosystem function. PMID:23638378

  6. Carbon Fluxes in a Managed Landscape: Assessing the Drivers of Temporal and Spatial Variability in Flux Tower, MODIS and Forest Inventory Data of the Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Wharton, S.; Bible, K.; Falk, M.; Paw U, K.

    2010-12-01

    This research focuses on the Wind Late Successional Reserve of Southern Washington where clear-cut logging over the past 100 years has created a fragmented landscape of coniferous forests that range in age from 0 to 500 years. In this study, we integrate several datasets to examine the environmental drivers of carbon exchange in this region across time and space. These sources include: (1) network of flux towers across a disturbance choronosequence, (2) MODIS Enhanced Vegetation Index, (3) aboveground net primary production (ANPP) from forest inventories, (4) and regional precipitation and air temperature measurements from the NOAA network of weather stations and PRISM reanalysis data. Net ecosystem exchange of carbon (NEE) has been measured at the Wind River Canopy Crane AmeriFlux site since 1998. The canopy crane is located in an old-growth forest composed of late seral Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla). Two flux towers were erected in early seral stands to study the effects of silviculture on net ecosystem exchange. CO2 uptake at the old-growth stand is highest in the spring before bud break when air and soil temperatures and vapor pressure deficit are relatively low, and soil moisture and light levels are favorable for photosynthesis, while maximum CO2 uptake is observed two to three months later at the early seral stands and coincide with peak leaf area index. This CO2 pattern is driven by different water conserving strategies. A reduction in carbon exchange is observed at the old-growth forest when moisture becomes limiting and canopy conductance rates drop sharply after mid-morning in the summer. In contrast, inhibition in canopy conductance rates and CO2 exchange is not observed at the early seral stands until soil moisture levels become critically low at the very end of the summer. The regional MODIS data (200 km X 200 km area) from 2000-2008 show that annual variability in the Enhanced Vegetation Index (EVI) also can be linked to precipitation and temperature anomalies at the stand level and across the region. Regional EVI anomalies are strongly negatively correlated with the annual precipitation and air temperature anomalies once the MODIS pixels are carefully examined with regards to forest age. EVI data from the tower-centered pixel also correlate well with annual NEE at the AmeriFlux site and show promise for scaling sparse flux tower observations, even over old-growth forests. Lastly, permanent plots have been continuously measured in the old-growth stand since 1947 and provide long-term data on tree demographics, recruitment, growth and mortality, and show evidence of decadal variability in response to precipitation and air temperature anomalies, as well as to disturbance (e.g., a Douglas-fir beetle kill in the 1950’s). We take advantage of the overlapping measurement period 1998-2004 and compare ANPP from the forest inventories to the flux tower estimates of NEE and MODIS EVI with focus on the regional environmental drivers.

  7. Acceleration of exotic plant invasion in a forested ecosystem by a generalist herbivore.

    PubMed

    Eschtruth, Anne K; Battles, John J

    2009-04-01

    The successful invasion of exotic plants is often attributed to the absence of coevolved enemies in the introduced range (i.e., the enemy release hypothesis). Nevertheless, several components of this hypothesis, including the role of generalist herbivores, remain relatively unexplored. We used repeated censuses of exclosures and paired controls to investigate the role of a generalist herbivore, white-tailed deer (Odocoileus virginianus), in the invasion of 3 exotic plant species (Microstegium vimineum, Alliaria petiolata, and Berberis thunbergii) in eastern hemlock (Tsuga canadensis) forests in New Jersey and Pennsylvania (U.S.A.). This work was conducted in 10 eastern hemlock (T. canadensis) forests that spanned gradients in deer density and in the severity of canopy disturbance caused by an introduced insect pest, the hemlock woolly adelgid (Adelges tsugae). We used maximum likelihood estimation and information theoretics to quantify the strength of evidence for alternative models of the influence of deer density and its interaction with the severity of canopy disturbance on exotic plant abundance. Our results were consistent with the enemy release hypothesis in that exotic plants gained a competitive advantage in the presence of generalist herbivores in the introduced range. The abundance of all 3 exotic plants increased significantly more in the control plots than in the paired exclosures. For all species, the inclusion of canopy disturbance parameters resulted in models with substantially greater support than the deer density only models. Our results suggest that white-tailed deer herbivory can accelerate the invasion of exotic plants and that canopy disturbance can interact with herbivory to magnify the impact. In addition, our results provide compelling evidence of nonlinear relationships between deer density and the impact of herbivory on exotic species abundance. These findings highlight the important role of herbivore density in determining impacts on plant abundance and provide evidence of the operation of multiple mechanisms in exotic plant invasion. PMID:19183209

  8. Invasive insect effects on nitrogen cycling and host physiology are not tightly linked.

    PubMed

    Rubino, Lucy; Charles, Sherley; Sirulnik, Abby G; Tuininga, Amy R; Lewis, James D

    2015-02-01

    Invasive insects may dramatically alter resource cycling and productivity in forest ecosystems. Yet, although responses of individual trees should both reflect and affect ecosystem-scale responses, relationships between physiological- and ecosystem-scale responses to invasive insects have not been extensively studied. To address this issue, we examined changes in soil nitrogen (N) cycling, N uptake and allocation, and needle biochemistry and physiology in eastern hemlock (Tsuga canadensis (L) Carr) saplings, associated with infestation by the hemlock woolly adelgid (HWA) (Adelges tsugae Annand), an invasive insect causing widespread decline of eastern hemlock in the eastern USA. Compared with uninfested saplings, infested saplings had soils that exhibited faster nitrification rates, and more needle (15)N uptake, N and total protein concentrations. However, these variables did not clearly covary. Further, within infested saplings, needle N concentration did not vary with HWA density. Light-saturated net photosynthetic rates (Asat) declined by 42% as HWA density increased from 0 to 3 adelgids per needle, but did not vary with needle N concentration. Rather, Asat varied with stomatal conductance, which was highest at the lowest HWA density and accounted for 79% of the variation in Asat. Photosynthetic light response did not differ among HWA densities. Our results suggest that the effects of HWA infestation on soil N pools and fluxes, (15)N uptake, needle N and protein concentrations, and needle physiology may not be tightly coupled under at least some conditions. This pattern may reflect direct effects of the HWA on N uptake by host trees, as well as effects of other scale-dependent factors, such as tree hydrology, affected by HWA activity. PMID:25721368

  9. A comparative toxicity assessment of materials used in aquatic construction.

    PubMed

    Lalonde, Benoit A; Ernst, William; Julien, Gary; Jackman, Paula; Doe, Ken; Schaefer, Rebecca

    2011-10-01

    Comparative toxicity testing was performed on selected materials that may be used in aquatic construction projects. The tests were conducted on the following materials: (1) untreated wood species (hemlock [Tsuga ssp], Western red cedar (Thuja plicata), red oak [Quercus rubra], Douglas fir [Pseudotsuga menziesii], red pine [Pinus resinosa], and tamarack [Larix ssp]); (2) plastic wood; (3) Ecothermo wood hemlock stakes treated with preservatives (e.g., chromated copper arsenate [CCA], creosote, alkaline copper quaternary [ACQ], zinc naphthenate, copper naphthenate, and Lifetime Wood Treatment); (4) epoxy-coated steel; (5) hot-rolled steel; (6) zinc-coated steel; and (7) concrete. Those materials were used in acute lethality tests with rainbow trout, Daphnia magna, Vibrio fischeri and threespine stickleback. The results indicated the following general ranking of the materials (from the lowest to highest LC(50) values); ACQ > creosote > zinc naphthenate > copper naphthenate > CCA (treated at 22.4 kg/m(3)) > concrete > red pine > western red cedar > red oak > zinc-coated steel > epoxy-coated steel > CCA (6.4 kg/m(3)). Furthermore, the toxicity results indicated that plastic wood, certain untreated wood species (hemlock, tamarack, Douglas fir, and red oak), hot-rolled steel, Ecothermo wood, and wood treated with Lifetime Wood Treatment were generally nontoxic to the test species. PMID:21222116

  10. Winter water relations of New England conifers and factors influencing their upper elevational limits. I. Measurements.

    PubMed

    Vostral, Chandra B; Boyce, Richard L; Friedland, Andrew J

    2002-08-01

    The upper elevational limits of tree species are thought to be controlled by abiotic factors such as temperature and the soil and atmospheric conditions affecting plant water status. We measured relative water contents (RWC), water potentials (Psi) and cuticular conductances (g(c)) of shoots of four conifer species-eastern hemlock (Tsuga canadensis (L.) Carr.), eastern white pine (Pinus strobus L.), red pine (P. resinosa Ait.) and red spruce (Picea rubens Sarg.)-during two winters on Mt. Ascutney, Vermont, USA. Some micrometeorological measurements are also reported. Eastern hemlock and white pine were studied near their upper elevational limits at a 640-m site, and red pine was studied near its upper elevational limit at 715 m. Red spruce was also studied at the 715-m site, which is in the middle of its elevational range on this mountain. There was no evidence of winter desiccation stress in any species. The observed distribution of seedlings suggested that the upper elevational limits on shade-intolerant eastern white pine and red pine are set by the absence of suitable seed beds after 100 years without fire. Eastern hemlock is able to reproduce in deep shade on organic substrates, but germination at high elevations may be restricted by low temperatures. PMID:12184983

  11. Quantifying residue after an intermediate harvest of a second-growth redwood stand

    SciTech Connect

    Woodward, R.A.; Henry, N.

    1985-01-01

    Logging residue at least 1.5 inches in diameter and 4 ft long was sampled in 1982, 6 yr after a harvest removing 40% of the b.a. (365 squared ft/acre) from a 90-yr-old second-growth stand in California. Historically, the stand was dominated by old growth Sequoia sempervirens, with Pseudotsuga menziesii, Abies grandis, Tsuga heterophylla and some Pinus muricata. Calble logging produced 844 cubic ft/acre of residue, 22% more than tractor logging (554 cubic ft/acre), possibly because of crushing and breakage by tractors during skidding. It is concluded that low volume and present markets make it uneconomical to use residues for building materials or fuel. 9 references.

  12. 6000-year record of forest history on Mount Rainier, Washington

    SciTech Connect

    Dunwiddie, P.W.

    1986-02-01

    Sediments in three ponds between 1300 - 1500 m on the south side of Mt. Rainier were examined for plant macrofossils and pollen. Macrofossils of seral species such as Abies lasiocarpa, Pseudotsuga menziesii, Pinus monticola, Abies procera, and Pinus contorta are conspicuous from 6000 to 3400 BP. These species suggest a climate that was warmer/drier than today and favored frequent fires. Neoglacial cooling may have begun 3700-3400 BP, as species typical of higher elevations became prominent; a decline in seral species after 3400 BP suggests less frequent fires. In the last 100 yr, Tsuga heterophylla became abundant and then declined at the highest elevation site. General trends in pollen percentages are similar to the macrofossil curves. Tephra deposition from Mt. Rainier and Mt. St. Helens did not produce conspicuous changes in forest composition. Few major fires are evident from charcoal and macrofossils at these sites.

  13. Recominant Pinoresino-Lariciresinol Reductase, Recombinant Dirigent Protein And Methods Of Use

    DOEpatents

    Lewis, Norman G.; Davin, Laurence B.; Dinkova-Kostova, Albena T.; Fujita, Masayuki , Gang; David R. , Sarkanen; Simo , Ford; Joshua D.

    2003-10-21

    Dirigent proteins and pinoresinol/lariciresinol reductases have been isolated, together with cDNAs encoding dirigent proteins and pinoresinol/lariciresinol reductases. Accordingly, isolated DNA sequences are provided from source species Forsythia intermedia, Thuja plicata, Tsuga heterophylla, Eucommia ulmoides, Linum usitatissimum, and Schisandra chinensis, which code for the expression of dirigent proteins and pinoresinol/lariciresinol reductases. In other aspects, replicable recombinant cloning vehicles are provided which code for dirigent proteins or pinoresinol/lariciresinol reductases or for a base sequence sufficiently complementary to at least a portion of dirigent protein or pinoresinol/lariciresinol reductase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding dirigent protein or pinoresinol/lariciresinol reductase. Thus, systems and methods are provided for the recombinant expression of dirigent proteins and/or pinoresinol/lariciresinol reductases.

  14. Synergistic effect of heartwood extractives and quaternary ammonium compounds on termite resistance of treated wood.

    PubMed

    Hwang, Won-Joung; Kartal, S Nami; Yoshimura, Tsuyoshi; Imamura, Yuji

    2007-01-01

    This study evaluates the synergistic effect of wood extractives and quaternary ammonium compounds (QACs) on the resistance to termites of several treated wood species. Wood specimens from different natural durability classes were extracted with either hot water alone or hot water + ethanol/benzene. The extracted and unextracted wood specimens were treated with either didecyldimethylammonium tetrafluoroborate (DBF) or commercial didecyldimethylammonium chloride (DDAC) solutions and then exposed to subterranean termites, Coptotermes formosanus Shiraki, for 3 weeks under laboratory conditions. The results showed that extractives of the heartwood portions of the wood species contributed to increased resistance against termite attack in the presence of either DBF or DDAC wood preservatives. The synergistic effect of wood extractives and DBF was much clearer with Pseudotsuga menziesii (Mirbel) Franco and Tsuga heterophylla Sarg wood samples. Further studies are needed for a better understanding of the synergism between wood extractives and either DBF or DDAC using both the sapwood and heartwood portions of the same wood species. PMID:17054087

  15. Controls on Nitrogen Retention and Loss in Urban and Rural Forest Ecosystems.

    NASA Astrophysics Data System (ADS)

    Templer, P. H.

    2011-12-01

    Human activities, such as the burning of fossil fuels and production of fertilizer, have increased the amount of nitrogen deposited onto terrestrial ecosystems. In addition to changes in atmospheric deposition of nitrogen, other human-induced disturbances have led to dramatic shifts in forest composition of the United States over the last 100 years. Tree species composition of many forests is changing in response to introduced pests and pathogens, competition with introduced plant species and changes in climate. Understanding the combined effects of increased nitrogen inputs and changes in plant species composition on forest nitrogen cycling is critical to our understanding of forest biogeochemistry and nutrient budgets. Despite several decades of research on the effects of atmospheric nitrogen deposition, there is still significant uncertainty about the factors that regulate nitrogen retention and loss in forest ecosystems. The use of natural abundance stable isotopes of nitrogen and oxygen has proven to be a powerful tool for tracing the sources of nitrate in water, from inputs to leaching, as it moves through an ecosystem. The evaluation of natural abundance nitrogen values in atmospheric deposition has been used to partition sources of nitrogen, such as coal-fired power plants vs. tailpipe exhaust, since each of their isotopic signatures is distinct. Similarly, natural abundance oxygen values of nitrate in atmospheric inputs and soil leachate have been used as a tool to partition sources of nitrate between precipitation and nitrate produced microbially during nitrification. We measured the natural abundance isotopic composition of nitrate to quantify rates of nitrogen inputs to the forest and to determine rates of nitrogen losses from healthy, declining and preemptively cut eastern hemlock (Tsuga canadensis) stands in both an urban forest at the Arnold Arboretum in Boston, MA, and a rural forest at Harvard Forest in Petersham, MA. The hemlock woolly adelgid (Adelges tsugae Annand), an introduced aphid-like insect from Japan, threatens hemlock stands throughout the eastern United States. The hemlock woolly adelgid was first reported in forests of the eastern United States in the early 1950s and is currently leading to mortality of eastern hemlock trees from Georgia to Massachusetts. We found that rates of nitrogen inputs to the forest floor were 4-5 times greater, and rates of nitrogen losses via leachate were more than ten times greater, at the Arnold Arboretum compared to Harvard Forest. Our results also show that current management regimes used to control the hemlock woolly adelgid, such as salvage cutting, may be reducing nitrogen losses in urban areas due to rapid regrowth of vegetation and the associated uptake of nitrogen by those plants. In contrast, cutting of trees in rural areas may be leading to proportionately greater losses of nitrogen in those sites, though the total magnitude of nitrogen lost is still smaller than in urban sites. Results of this study suggest that the combination of the hemlock woolly adelgid, atmospheric nitrogen inputs and management practices lead to changes in the nitrogen cycle within eastern hemlock forest ecosystems.

  16. Proteomic analysis of Corylus heterophylla fisch in Changbai Mountain by shotgun approach.

    PubMed

    Chunlei, Liu; Weihong, Min; Jingsheng, Liu; Yan, Liu; Jingxi, Ma; Jingjing, Li

    2015-07-01

    Total proteins of Changbai Mountain hazelnut were extracted and then enzymolysed in solution. The mixture of peptides was separated on chromatograph and identified by shotgun proteomics approach. The identified proteins were analyzed by bioinformatics, 303 proteins were identified, of which 237 proteins (78.2%) were mainly distributing in a range of 10-70 kDa and 85 proteins (28.1%) were around pI 5-6. Based on the biological process cellular component and molecular function, these proteins were classified by Gene Ontology, the results showed that 183 proteins (73.8%) had catalytic activity (e.g. oxidoreductase, kinase, peptidase, etc.), and 170 proteins (68.5%) had binding activity. The protein profile provided a valuable basis for further research of hazelnut proteins and opened up new research avenues related to the function of these proteins. PMID:26431657

  17. Stand characteristics of 65-year-old planted and naturally regenerated stands near Sequim, Washington. Forest Service research paper

    SciTech Connect

    Miller, R.E.; Anderson, H.W.

    1995-04-01

    Tree numbers, height, and volume were determined in six 63- to 66-year-old plantations of coast Douglas-fir (Pseudotsunga menziesii) (Mirb.) Franco var. menziesii in northwest Washington. These stands resulted from the first extensive plantings of this species in the Pacific Northwest. Data from 0.25-acre plots in these plantations were compared to those from matched plots in adjacent, naturally regenerated stands with the same history of logging, wildfire, and absence of further siviculture after regeneration. Planting resulted in well-stocked Douglas-fir stands with volunteers of other tree species. Natural seeding resulted in similarly stocked stands of western hemlock (Tsunga heterophylla) (Raf.) (Sarg.) with Douglas-fir in the dominant crown class.

  18. Response of high-elevation forests in the Olympic Mountains to climatic change

    USGS Publications Warehouse

    Zolbrod, A.N.; Peterson, D.L.

    1999-01-01

    The gap model ZELIG was used to examine the effects of increased temperature (2A?C) and altered precipitation on high-elevation ecosystems of the Olympic Mountains, Washington, U.S.A. Changes in tree species distribution and abundance, as well as stand biomass, were examined on north and south aspects in the dry northeast (NE) and wet southwest (SW) regions of the Olympics for (i) warmer, (ii) warmer and 20% wetter, and (iii) warmer and 20% drier climatic-change scenarios. Dominant tree species shift upwards 300-600 m in elevation in the SW, with subalpine meadows and Tsuga mertensiana (Bong.) Carr. forests being replaced by Abies amabilis (Dougl.) Forbes forests at higher elevations and A. amabilis forests being replaced by Tsuga heterophylla (Raf.) Sarg. forests at lower elevations. In the NE, drought-tolerant species become dominant approximately 200 m lower than present, with A. lasiocarpa dominating the north aspect and Pinus contorta Dougl. ex Loud. the south aspect. Biomass increases in the SW and generally decreases in the NE, depending on aspect and precipitation regime. This study suggests that species and site-specific responses at mesoscale (e.g., wet vs. dry climatic regime) and microscale (e.g., north vs. south aspect) resolutions must be characterized to quantify the variation in potential effects of climatic change on forest vegetation in mountainous regions.

  19. Climate determines upper, but not lower, altitudinal range limits of Pacific Northwest conifers.

    PubMed

    Ettinger, A K; Ford, K R; HilleRisLambers, J

    2011-06-01

    Does climate determine species' ranges? Rapid rates of anthropogenic warming make this classic ecological question especially relevant. We ask whether climate controls range limits by quantifying relationships between climatic variables (precipitation, temperature) and tree growth across the altitudinal ranges of six Pacific Northwestern conifers on Mt. Rainier, Washington, USA. Results for three species (Abies amabilis, Callitropsis nootkatensis, Tsuga mertensiana) whose upper limits occur at treeline (> 1600 m) imply climatic controls on upper range limits, with low growth in cold and high snowpack years. Annual growth was synchronized among individuals at upper limits for these high-elevation species, further suggesting that stand-level effects such as climate constrain growth more strongly than local processes. By contrast, at lower limits climatic effects on growth were weak for these high-elevation species. Growth-climate relationships for three low-elevation species (Pseudotsuga menziesii, Thuja plicata, Tsuga heterophylla) were not consistent with expectations of climatic controls on upper limits, which are located within closed-canopy forest (< 1200 m). Annual growth of these species was poorly synchronized among individuals. Our results suggest that climate controls altitudinal range limits at treeline, while local drivers (perhaps biotic interactions) influence growth in closed-canopy forests. Climate-change-induced range shifts in closed-canopy forests will therefore be difficult to predict accurately. PMID:21797160

  20. A 14,000 year vegetation history of a hypermaritime island on the outer Pacific coast of Canada based on fossil pollen, spores and conifer stomata

    NASA Astrophysics Data System (ADS)

    Lacourse, Terri; Delepine, J. Michelle; Hoffman, Elizabeth H.; Mathewes, Rolf W.

    2012-11-01

    Pollen and conifer stomata analyses of lake sediments from Hippa Island on the north coast of British Columbia were used to reconstruct the vegetation history of this small hypermaritime island. Between 14,000 and 13,230 cal yr BP, the island supported diverse herb-shrub communities dominated by Cyperaceae, Artemisia and Salix. Pinus contorta and Picea sitchensis stomata indicate that these conifers were present among the herb-shrub communities, likely as scattered individuals. Transition to open P. contorta woodland by 13,000 cal yr BP was followed by increases in Alnus viridis, Alnus rubra and P. sitchensis. After 12,000 cal yr BP, Pinus-dominated communities were replaced by dense P. sitchensis and Tsuga heterophylla forest with Lysichiton americanus and fern understory. Thuja plicata stomata indicate that this species was present by 8700 cal yr BP, but the pollen record suggests that its populations did not expand to dominate regional rainforests, along with Tsuga and Picea, until after 6600 cal yr BP. Conifer stomata indicate that species may be locally present for hundreds to thousands of years before pollen exceed thresholds routinely used to infer local species arrival. When combined, pollen and conifer stomata can provide a more accurate record of paleovegetation than either when used alone.

  1. Migration of tree species in New England based on elevational and regional analyses. Forest Service research paper (Final)

    SciTech Connect

    Solomon, D.S.; Leak, W.B.

    1994-07-20

    With field measurements of migration patterns, we used two complementary approaches to examine tree-species movement after a documented increase in temperature. The advancing-front theory was used to examine age trends over distance and elevation for both a mountain site in New Hampshire and a regional comparison across the State of Maine. Well-defined stationary fronts were identified for red spruce (Picea rubens) and beech (Fagus grandifolia), while a catastrophic front was depicted for sugar maple (Acer saccharum) and a constant slow-moving advancing front was exhibited by hemlock (Tsuga canadensis). The regional analysis, in Maine, indicated that white pine (Pinus strobus) and balsam fir (Abies balsamea) decreased significantly in average latitude and elevation over a 24-year period. The potential ranges of the major species in terms of elevation and regional position appear stable.

  2. Habitat classification: A comparison using avian species and guilds

    NASA Astrophysics Data System (ADS)

    Degraaf, Richard M.; Chadwick, Nan L.

    1984-11-01

    Results of breeding bird censuses in 1979 and 1980 were used to compare the relationships of both species and guilds to forest habitats in the White Mountains of New Hampshire. Several age classes of 11 forest cover types were studied: northern hard-woods ( Fagus-Betula-Acer), spruce ( Picea), spruce-fir ( Picea-Abies), birth ( Betula), swamp hardwoods ( Acer-Pinus-Tsuga), pine ( Pinus strobus and P. resinosa), balsam fir ( Abies), aspen ( Populus tremuloides and P. grandidentata), northern red oak ( Quercus), oak-pine ( Quercus-Pinus), and hemlock ( Tsuga). All types were even-aged; only northern hardwoods had an additional uneven-aged condition. Forest cover types were also pooled to consider generalized habitats: hardwoods, mixed forest, or softwoods. Results of ordinations based on censuses of 74 bird species indicate that foraging guilds are more related to general cover types than are nesting substrate guilds, but bird species reflect habitat differences to a greater degree than do either guild scheme. Also, considerable overlap occurs in bird species distribution between hardwoods and mixed forests; softwoods show little overlap with other types. Discriminant function and classification analyses revealed that bird species composition can be used to correctly classify general forest habitats more accurately (83.8%) than either foraging (63.2%) or nesting substrate guilds (58.4%). These results indicate that, of the habitats studied, avian species compositions are more characteristic than are foraging or nesting substrate guild composition, which tend to be similar across forest habitats.

  3. 76 FR 63282 - Foreign-Trade Zone 140-Flint, Michigan; Application for Subzone; Hemlock Semiconductor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-12

    ... distribution of polysilicon, monosilane gas, silicon tetrachloride, trichlorosilane, dichlorosilane, hydrogen... value of the finished product) include: silicon metal, silicon tetrachloride, trichlorosilanes and... prohibiting the admission of foreign status silicon metal subject to an antidumping or countervailing...

  4. The future of bioethics: three dogmas and a cup of hemlock.

    PubMed

    Dawson, Angus

    2010-06-01

    In this paper I argue that bioethics is in crisis and that it will not have a future unless it begins to embrace a more Socratic approach to its leading assumptions. The absence of a critical and sceptical spirit has resulted in little more than a dominant ideology. I focus on three key issues. First, that too often bioethics collapses into medical ethics. Second, that medical ethics itself is beset by a lack of self-reflection that I characterize here as a commitment to three dogmas. Third, I offer a more positive perspective by suggesting how bioethics may benefit from looking towards public health ethics as a new source of inspiration and direction. PMID:20500759

  5. 75 FR 28232 - Availability of an Environmental Assessment for a Biological Control Agent for Hemlock Woolly...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-20

    ... Service (APHIS) is proposing to issue permits for the release of an insect, Laricobius osakensis, into the... alternatives to, the release of an insect, Laricobius osakensis, into the continental United States for use as... to Docket No. APHIS-2010-0029. Reading Room: You may read any comments that we receive on...

  6. Climate, geography, and tree establishment in Subalpine Meadows of the Olympic Mountains, Washington, U.S.A.

    SciTech Connect

    Woodward, A.; Silsbee, D.G.; Schreiner, E.G.

    1995-08-01

    Noticeable changes in vegetation distribution have occurred in the Pacific Northwest during the last century as trees have established in some subalpine meadows. To study the relationship of this process to climate, recently established trees were aged in six subalpine meadows in the Olympic Mountains, Washington. The sites represent three points along a steep precipitation gradient. Subalpine fir (Abies lasiocarpa) has been establishing at the dry end of the gradient, mountain hemlock (Tsuga mertensiana) at the wet end, and both species in the center. Establishment patterns were compared with deviations from the century-long average for these weather variables: winter precipitation, Palmer Drought Severity Index, and winter, October and May temperatures. Results show that establishment occurred in dry areas when weather conditions were wetter than average, and in wet areas under drier than average conditions. Establishment at central sites did not show consistent relationships with climate. If future climatic conditions continue to warm, establishment of subalpine fir in subalpine meadows in dry areas may cease and mountain hemlock may resume in wet areas. 34 refs., 5 figs., 3 tabs.

  7. Climate, geography, and tree establishment in subalpine meadows of the Olympic Mountains, Washington, USA

    USGS Publications Warehouse

    Woodward, Andrea; Schreiner, Edward G.; Silsbee, D.G.

    1995-01-01

    Noticeable changes in vegetation distribution have occurred in the Pacific Northwest during the last century as trees have established in some subalpine meadows. To study the relationship of this process to climate, recently established trees were aged in six subalpine meadows in the Olympic Mountains, Washington. The sites represent three points along a steep precipitation gradient. Subalpine fir (Abies lasiocarpa) has been establishing at the dry end of the gradient, mountain hemlock (Tsuga mertensiana) at the wet end, and both species in the center. Establishment patterns were compared with deviations from the century-long average for these weather variables: winter precipitation, Palmer Drought Severity Index, and winter, October, and May temperatures. Results show that establishment occurred in dry areas when weather conditions were wetter than average, and in wet areas under drier than average conditions. Establishment at central sites did not show consistent relationships with climate. If future climatic conditions continue to warm, establishment of subalpine fir in subalpine meadows in dry areas may cease and mountain hemlock may resume in wet areas.

  8. Sirococcus conigenus, Sirococcus piceicola, sp. nov. and Sirococcus tsugae sp. nov. on conifers: anamorphic fungi in the Gnomoniaceae, Diaporthales

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sirococcus is a genus of asexually reproducing fungi that includes important pathogens causing shoot blight and tip dieback of conifers. In this paper the type species of Sirococcus, S. conigenus, is redescribed, illustrated, and an epitype designated. In addition, two new species are recognized....

  9. Pistillate flower development and pollen tube growth mode during the delayed fertilization stage in Corylus heterophylla Fisch.

    PubMed

    Liu, Jianfeng; Zhang, Huidi; Cheng, Yunqing; Kafkas, Salih; Güney, Murat

    2014-09-01

    Unlike most angiosperms, in which fertilization occurs within several days after pollination, fertilization in hazel (Corylus Spp.) is delayed by two to three and a half months. However, the female inflorescences or young fruits are too hard or lignified to be dissected according to regular paraffin sectioning technique. So, what the nature of development during the extended progamic phases of hazel remains unknown. The female inflorescence development and pollen tube growth mode during the delayed fertilization stage in hazel were investigated by improved paraffin sectioning and aniline blue staining of pollen tubes. The results showed ovaries and ovules of hazel were invisible at the time of blooming. Early ovary and ovule primordium began to form from 15 to 20 days after blooming, respectively. Integument and mature embryo sacs differentiated from the nucellus on 40th and 55th day after blooming, respectively. Pollen tubes were retarded in the bottom of the style or the pollen tube cavity (PTC, a specifical lignified cavity structure at the bottom of style for pollen tube to rest during progamic phase) for about 26 days. Then, the pollen tubes were observed to leave the PTC and began to enter the ovary. After that, a single pollen tube passed through the vicinity of the micropyle. Finally, pollen tubes turned a corner and penetrated the embryo sac through the tissue of the chalaza instead of micropyle on 52 and 55 days after blooming, respectively. The results of more in-depth information will be beneficial to better understanding of the delayed fertilization process in hazel. PMID:25073757

  10. Effects of late holocene forest disturbance and vegetation change on acidic mud pond, Maine, USA

    SciTech Connect

    Rhodes, T.E.; Davis, R.B.

    1995-04-01

    The limnological effects of natural forest disturbance and succession were studied by analyzing the chemistry, charcoal, pollen, chrysophytes, and diatoms in sediments deposited from {approx}3500 to {approx}700 yr BP in Mud Pond, Maine. Fine-grained sediments rich in organic matter are interrupted every 100-500 yr ({bar X} = 280) by coarser, more minerogenic sediments, reflecting soil erosion. The disturbance horizons contain high concentrations of charcoal, indicating forest fires, low percentages of pollen of late-successional trees such as Tsuga, and high percentages of pollen and spores of early-successional plants such as shrubs and ferns. Within a few decades, pollen percentages of Alnus peak, followed by Betula. Tsuga pollen percentages increase for 200-400 yr after disturbances, and generally stabilize or decrease several decades before the next disturbance. Limnological responses to these changes are indicated by high percentages of diatoms and chrysophytes of waters of near neutral pH. Diatom-inferred pH typically increases abruptly from {approx}5.0 to {approx}6.1, and chrysophyte-inferred pH from {approx}5.5 to {approx}5.8 at disturbance horizons. These increases may be caused by increased wood ash and mineral soils after disturbances. This pulse is followed by a two-step recovery. First the inferred pH decreases nearly to the pre-disturbance condition. This response likely results from soil stabilization and uptake of base cations by successional vegetation. Second, a slower acidification of {approx}0.1 pH unit per century occurs as early successional shrubs and hardwood forest are replaced by old-growth conifer forest. Increasing percentages of pollen of Picea, Alnus, and Salix by 1350 yr BP, and decreasing percentages of hemlock and beech around 1350 yr BP imply cooler conditions. Large changes in diatom and chrysophyte assemblages in approximately this period may be related. 64 refs., 8 figs., 3 tabs.

  11. A multi-scale conceptual model of fire and disease interactions in North American forests

    NASA Astrophysics Data System (ADS)

    Varner, J. M.; Kreye, J. K.; Sherriff, R.; Metz, M.

    2013-12-01

    One aspect of global change with increasing attention is the interactions between irruptive pests and diseases and wildland fire behavior and effects. These pests and diseases affect fire behavior and effects in spatially and temporally complex ways. Models of fire and pathogen interactions have been constructed for individual pests or diseases, but to date, no synthesis of this complexity has been attempted. Here we synthesize North American fire-pathogen interactions into syndromes with similarities in spatial extent and temporal duration. We base our models on fire interactions with three examples: sudden oak death (caused by the pathogen Phytopthora ramorum) and the native tree tanoak (Notholithocarpus densiflorus); mountain pine beetle (Dendroctonus ponderosae) and western Pinus spp.; and hemlock woolly adelgid (Adelges tsugae) on Tsuga spp. We evaluate each across spatial (severity of attack from branch to landscape scale) and temporal scales (from attack to decades after) and link each change to its coincident effects on fuels and potential fire behavior. These syndromes differ in their spatial and temporal severity, differentially affecting windows of increased or decreased community flammability. We evaluate these models with two examples: the recently emergent ambrosia beetle-vectored laurel wilt (caused by the pathogen Raffaelea lauricola) in native members of the Lauraceae and the early 20th century chestnut blight (caused by the pathogen Cryphonectria parasitica) that led to the decline of American chestnut (Castanea dentata). Some changes (e.g., reduced foliar moisture content) have short-term consequences for potential fire behavior while others (functional extirpation) have more complex indirect effects on community flammability. As non-native emergent diseases and pests continue, synthetic models that aid in prediction of fire behavior and effects will enable the research and management community to prioritize mitigation efforts to realized effects.

  12. The non-competitive blockade of GABAA receptors by an aqueous extract of water hemlock )Cicuta douglassi) tubers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Teratogenic alkaloids can cause developmental defects due to the inhibition of fetal movement from the desensitization of fetal muscle-type nicotinic acetylcholine receptors (nAChR). In this study, we tested the hypothesis that the piperidine alkaloid anabaseine a 1,2-dehydropiperidine and anabasin...

  13. 76 FR 63281 - Foreign-Trade Zone 78-Nashville, TN, Application for Subzone, Hemlock Semiconductor, L.L.C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-12

    ... acres, 10,000 metric tons capacity) is located at 1000 Solar Way, Clarksville, Tennessee. The facility..., trichlorosilane, dichlorosilane, hydrogen chloride and direct process residue. Components and materials...

  14. Quantifying canopy complexity and effects on productivity and resilience in late-successional hemlock-hardwood forests.

    PubMed

    Fahey, Robert T; Fotis, Alexander T; Woods, Kerry D

    2015-04-01

    The regrowing forests of eastern North America have been an important global C sink over the past 100+ years, but many are now transitioning into late succession. The consequences of this transition are unclear due to uncertainty around the C dynamics of old- growth forests. Canopy structural complexity (CSC) has been shown to be an important source of variability in C dynamics in younger forests (e.g., in productivity and resilience to disturbance), but its role in late-successional forests has not been widely addressed. We investigated patterns of CSC in two old-growth forest landscapes in the Upper Peninsula of Michigan, USA, to assess factors associated with CSC and its influence on productivity and disturbance resilience (to moderate-severity windstorm). CSC was quantified using a portable below-canopy LiDAR (PCL) system in 65 plots that also had long-term (50-70+ years). inventory data, which were used to quantify aboveground net primary productivity (ANPP), disturbance history, and stand characteristics. We found high and variable CSC relative to younger forests across a suite of PCL-derived metrics. Variation in CSC was driven by species composition and size structure, rather than disturbance history or site characteristics. Recent moderate severity wind disturbance decreased plot-scale CSC, but increased stand-scale variation in CSC. The strong positive correlation between CSC and productivity illustrated in younger forests was not present in undisturbed portions of these late-successional ecosystems. Moderate severity disturbance appeared to reestablish the positive link between CSC and productivity, but this relationship was scale and severity dependent. A positive CSC-productivity relationship was evident at the plot scale with low-severity, dispersed disturbance, but only at a patch scale in more severely disturbed areas. CSC does not appear to strongly correlate With variation in productivity in undisturbed old-growth forests, but may play a very important (and scale/severity-dependent) role in their response to disturbance. Understanding potential, drivers and consequences of CSC in late-successional forests will inform management focused on promoting complexity and old-growth conditions, and illustrate potential inipacts of such treatments on regional C dynamics. PMID:26214927

  15. SPECIES-SPECIFIC PARTITIONING OF SOIL WATER RESOURCES IN AN OLD-GROWTH DOUGLAS-FIR/WESTERN HEMLOCK FOREST

    EPA Science Inventory

    Although tree- and stand-level estimates of forest water use are increasingly common, relatively little is known about partitioning of soil water resources among co-occurring tree species. We studied seasonal courses of soil water utilization in a 450-year-old Pseudotsuga menzies...

  16. Reducing Losses of Nitrogen from Duff Consumption by Prescribed Fire in Douglas-Fir/Western Hemlock Clearcuts : Final Report.

    SciTech Connect

    Little, Susan N.; Ohmann, Janet L.

    1985-06-28

    The purpose of this study was to determine if nitrogen loss from prescribed fire can be mitigated by reducing the amount of large fuel on a clearcut prior to burning. We examine the relations between nitrogen loss and duff consumption by prescribed fire with respect to the amount of woody biomass on the unit and the moisture content of that biomass before burn. Equations are presented to predict duff consumption from preburn conditions. Sources of variability of nitrogen concentration and content of duff within and between units are also evaluated.

  17. Bryophyte species associations with coarse woody debris and stand ages in Oregon

    USGS Publications Warehouse

    Rambo, T.; Muir, Patricia S.

    1998-01-01

    We quantified the relationships of 93 forest floor bryophyte species, including epiphytes from incorporated litterfall, to substrate and stand age in Pseudotsuga menziesii-Tsuga heterophylla stands at two sites in western Oregon. We used the method of Dufr??ne and Legendre that combines a species' relative abundance and relative frequency, to calculate that species' importance in relation to environmental variables. The resulting 'indicator value' describes a species' reliability for indicating the given environmental parameter. Thirty-nine species were indicative of either humus, a decay class of coarse woody debris, or stand age. Bryophyte community composition changed along the continuum of coarse woody debris decomposition from recently fallen trees with intact bark to forest floor humus. Richness of forest floor bryophytes will be enhanced when a full range of coarse woody debris decay classes is present. A suite of bryophytes indicated old-growth forest. These were mainly either epiphytes associated with older conifers or liverworts associated with coarse woody debris. Hardwood-associated epiphytes mainly indicated young stands. Mature conifers, hardwoods, and coarse woody debris are biological legacies that can be protected when thinning managed stands to foster habitat complexity and biodiversity, consistent with an ecosystem approach to forest management.

  18. Impacts of Invasive Pests on Forest Carbon and Nitrogen Dynamics

    NASA Astrophysics Data System (ADS)

    Lovett, G. M.; Crowley, K. F.

    2014-12-01

    Forests of the U.S. have been subject to repeated invasions of destructive insects and diseases imported from other continents. Like other disturbances, these pests can produce short-term ecosystem effects due to tree mortality, but unlike other disturbances, they often target individual species and therefore can cause long-term species change in the forest. Because tree species vary in their influence on carbon (C) and nitrogen (N) cycles, pest-induced species change can radically alter the biogeochemistry of a forest. In this paper we use both data and modeling to examine how pest-induced species change may alter the C and N cycling in forests of the eastern U.S. We describe a new forest ecosystem model that distinguishes individual tree species and allows species composition to shift over the course of the model run. Results indicate that the mortality of eastern hemlock (Tsuga canadensis) by hemlock woolly adelgid and its replacement by faster-growing species such as black birch (Betula lenta) will reduce forest floor C stocks but increase productivity as the birch become established. Decline of American beech (Fagus grandifolia) from beech bark disease and its replacement by sugar maple (Acer saccharum) is likely to decrease soil C storage and increase N leaching from the ecosystem. Responses to other invasive pests will also be discussed. The magnitude of these species-specific effects on C and N cycling is in many cases larger than direct effects expected from changes in climate and atmospheric N deposition, indicating that species change should be included in models that predict forest ecosystem function under future environmental conditions.

  19. Dendroclimatic estimates of a drought index for northern Virginia

    USGS Publications Warehouse

    Puckett, Larry J.

    1981-01-01

    A 230-year record of the Palmer drought-severity index (PDSI) was estimated for northern Virginia from variations in widths of tree rings. Increment cores were extracted from eastern hemlock, Tsuga canadensis (L.) Carr., at three locations in northern Virginia. Measurements of annual growth increments were made and converted to standardized indices of growth. A response function was derived for hemlock to determine the growth-climate relationship. Growth was positively correlated with precipitation and negatively correlated with temperature during the May-July growing season. Combined standardized indices of growth were calibrated with the July PDSI. Growth accounted for 20-30 percent of the PDSI variance. Further regressions using factor scores of combined tree growth indices resulted in a small but significant improvement. Greatest improvement was made by using factor scores of growth indices of individual trees, thereby accounting for 64 percent of the July PDSI variance in the regression. Comparison of the results with a 241-year reconstruction from New York showed good agreement between low-frequency climatic trends. Analysis of the estimated Central Mountain climatic division of Virginia PDSI record indicated that, relative to the long-term record (1746-1975), dry years have occurred in disproportionally larger numbers during the last half of the 19th century and the mid-20th century. This trend appears reversed for the last half of the 18th century and the first half of the 19th century. Although these results are considered first-generation products, they are encouraging, suggesting that once additional tree-ring chronologies are constructed and techniques are refined, it will be possible to obtain more accurate estimates of prior climatic conditions in the mid-Atlantic region.

  20. Interactions of Carbon Gain and Nitrogen Addition in a Temperate Forest

    NASA Astrophysics Data System (ADS)

    Bazzaz, F. A.

    2001-12-01

    In plants, carbon and nitrogen are intimately related. The plant gains carbon using nitrogen because it is a major constituent of both the light reaction (chlorophyll) and dark reaction (Rubisco and PEP carboxylase). The plant also gains more nitrogen by using carbon to grow roots that can forage for nitrogen, especially the less mobile (NH4+). Rising CO2 and increased nitrogen deposition are important elements of global change, both of which may affect ecosystem structure and function. They may cause a particularly large shift in species composition in systems where contrasting groups of species co-occur, e.g. evergreen coniferous and deciduous broad-leaved tree species. We studied the impact of nitrogen deposition in a mixed forest in central Massachusetts (Harvard Forest). We found that the early-successional broad-leaved species, yellow birch (Betula alleghaniensis) and red maple (Acer rubrum), both showed large increases in biomass, while the late successional species sugar maple (Acer saccharum) and all the coniferous species, hemlock (Tsuga canadensis), red spruce (Picea rubens) and white pine (Pinus strobus), only showed slight increases. As a result, when these species wre grown together, there was a decrease in species diversity. There was a significant correlation between species growth rate and the growth enhancement following nitrogen addition. We used SORTIE, a spatially explicit forest model to speculate about the future of this community. In both hemlock and red oak stands, nitrogen deposition led to shift in forest composition towards further dominance of young forests by yellow birch. We conclude that seedling physiological and demographic responses to increased nitrogen availability will scale up to exaggerate successional dynamics in mixed temperate forests in the future

  1. Plant and soil natural abundance delta (15)N: indicators of relative rates of nitrogen cycling in temperate forest ecosystems.

    PubMed

    Templer, Pamela H; Arthur, Mary A; Lovett, Gary M; Weathers, Kathleen C

    2007-08-01

    Watersheds within the Catskill Mountains, New York, receive among the highest rates of nitrogen (N) deposition in the northeastern United States and are beginning to show signs of N saturation. Despite similar amounts of N deposition across watersheds within the Catskill Mountains, rates of soil N cycling and N retention vary significantly among stands of different tree species. We examined the potential use of delta (15)N of plants and soils as an indicator of relative forest soil N cycling rates. We analyzed the delta (15)N of foliage, litterfall, bole wood, surface litter layer, fine roots and organic soil from single-species stands of American beech (Fagus grandifolia), eastern hemlock (Tsuga canadensis), red oak (Quercus rubra), and sugar maple (Acer saccharum). Fine root and organic soil delta (15)N values were highest within sugar maple stands, which correlated significantly with higher rates of net mineralization and nitrification. Results from this study suggest that fine root and organic soil delta (15)N can be used as an indicator of relative rates of soil N cycling. Although not statistically significant, delta (15)N was highest within foliage, wood and litterfall of beech stands, a tree species associated with intermediate levels of soil N cycling rates and forest N retention. Our results show that belowground delta (15)N values are a better indicator of relative rates of soil N cycling than are aboveground delta (15)N values. PMID:17479293

  2. Observations of summer roosting and foraging behavior of a hoary bat (Lasiurus cinereus) in southern New Hampshire.

    SciTech Connect

    Veillieux, J. P.; Moosman, P. R.; Reynolds, D. S.; LaGory, K. E.; Walston, L. J.; Environmental Science Division; Franklin Pierce Univ.; Fitchburg State Coll.; St. Paul's School

    2009-01-01

    Few data are available that describe the roosting and foraging ecology of the Hoary Bat (Lasiurus cinereus), and no such data are available for the northeastern United States. We captured a juvenile Hoary Bat in south-central New Hampshire during July of 2007 and monitored its roosting behavior for ten days and its foraging behavior for one night. The bat roosted with two other bats, which we presumed were its mother and sibling. These bats roosted exclusively in Tsuga canadensis (Eastern Hemlock Tree) and tended to roost near tree tops in the forest canopy. The radiotagged bat used at least six roost trees and changed roost location eight times during the ten-day observation period. Although roost-tree fidelity was low, all roost trees were located within a maximum circular area of 0.5 ha. The bat foraged over an estimated 156-ha area of mostly forest habitat (68%), with additional open habitats (15%) and wetlands (17%). These data are the first observations of roosting and foraging behaviors by the Hoary Bat in the northeastern region of its geographic range.

  3. Relationships among environmental variables and distribution of tree species at high elevation in the Olympic Mountains

    USGS Publications Warehouse

    Woodward, Andrea

    1998-01-01

    Relationships among environmental variables and occurrence of tree species were investigated at Hurricane Ridge in Olympic National Park, Washington, USA. A transect consisting of three plots was established down one north-and one south-facing slope in stands representing the typical elevational sequence of tree species. Tree species included subalpine fir (Abies lasiocarpa), Douglas-fir (Pseudotsuga menziesii), mountain hemlock (Tsuga mertensiana), and Pacific silver fir (Abies amabilis). Air and soil temperature, precipitation, and soil moisture were measured during three growing seasons. Snowmelt patterns, soil carbon and moisture release curves were also determined. The plots represented a wide range in soil water potential, a major determinant of tree species distribution (range of minimum values = -1.1 to -8.0 MPa for Pacific silver fir and Douglas-fir plots, respectively). Precipitation intercepted at plots depended on topographic location, storm direction and storm type. Differences in soil moisture among plots was related to soil properties, while annual differences at each plot were most often related to early season precipitation. Changes in climate due to a doubling of atmospheric CO2 will likely shift tree species distributions within, but not among aspects. Change will be buffered by innate tolerance of adult trees and the inertia of soil properties.

  4. Acid rain, air pollution, and tree growth in southeastern New York

    SciTech Connect

    Puckett, L.J.

    1982-07-01

    Whether dendroecological analyses could be used to detect changes in the relationship of tree growth to climate that might have resulted from chronic exposure to components of the acid rain-air pollution complex was determined. Tree-ring indices of white pine (Pinus strobus L.), eastern hemlock (Tsuga canadensis (L.) Carr.), pitch pine (Pinus rigida Mill.), and chestnut oak (Quercus prinus L.) were regressed against orthogonally transformed values of temperature and precipitation in order to derive a response-function relationship. Results of the regression analyses for three time periods, 1901-1920, 1926-1945, and 1954-1973 suggest that the relationship of tree growth to climate has been altered. Statistical tests of the temperature and precipitation data suggest that this change was nonclimatic. Temporally, the shift in growth response appears to correspond with the suspected increase in acid rain and air pollution in the Shawangunk Mountain area of southeastern New York in the early 1950's. This change could be the result of physiological stress induced by components of the acid rain-air pollution complex, causing climatic conditions to be more limiting to tree growth.

  5. Late Quaternary Water-Level Variations and Vegetation History at Crooked Pond, Southeastern Massachusetts

    NASA Astrophysics Data System (ADS)

    Shuman, Bryan; Bravo, Jennifer; Kaye, Jonathan; Lynch, Jason A.; Newby, Paige; Webb, Thompson, III

    2001-11-01

    Sediment cores collected along a transect in Crooked Pond, southeastern Massachusetts, provide evidence of water-level changes between 15,000 cal yr B.P. and present. The extent of fine-grained, detrital, organic accumulation in the basin, inferred from sediment and pollen stratigraphies, varied over time and indicates low water levels between 11,200 and 8000 cal yr B.P. and from ca. 5300 to 3200 cal yr B.P. This history is consistent with the paleohydrology records from nearby Makepeace Cedar Swamp and other sites from New England and eastern Canada and with temporal patterns of regional changes in effective soil moisture inferred from pollen data. The similarities among these records indicate that (1) regional conditions were drier than today when white pine ( Pinus strobus) grew abundantly in southern New England (11,200 to 9500 cal yr B.P.); (2) higher moisture levels existed between 8000 and 5500 cal yr B.P., possibly caused by increased meridonal circulation as the influence of the Laurentide ice sheet waned; and (3) drier conditions possibly contributed to the regional decline in hemlock ( Tsuga) abundances at 5300 cal yr B.P. Although sea-level rise may have been an influence, moist climatic conditions during the late Holocene were the primary reason for a dramatic rise in water-table elevations.

  6. Winter water relations of New England conifers and factors influencing their upper elevational limits. II. Modeling.

    PubMed

    Boyce, Richard L; Vostral, Chandra B; Friedland, Andrew J

    2002-08-01

    We used the water relations model, WINWAT, to model winter water relations of three conifer species-eastern hemlock (Tsuga canadensis (L.) Carr.), eastern white pine (Pinus strobus L.) and red pine (P. resinosa Ait.)-growing at their upper elevational limits on Mt. Ascutney, Vermont, USA, in the winters of 1997 and 1999. Modeled relative water contents remained above 60% in the two youngest foliar age classes of all three species during both winters, indicating that desiccation stress in winter is not responsible for setting the upper elevational limits of these species at this site under present climatic conditions. WINWAT indicated that winter water relations of these low-elevational species were sensitive to low relative humidity, which increased transpiration rates, and low temperatures, which inhibited recharge, but are much less sensitive to summer climate than in the case of subalpine conifers in Colorado. Our results indicate that summer and winter temperatures and relative humidities (or precipitation/potential evapotranspiration ratios) should be incorporated into climate change models designed to simulate future tree distributions. PMID:12184984

  7. Nonadditive effects of leaf litter species diversity on breakdown dynamics in a detritus-based stream.

    PubMed

    Kominoski, J S; Pringle, C M; Ball, B A; Bradford, M A; Coleman, D C; Hall, D B; Hunter, M D

    2007-05-01

    Since species loss is predicted to be nonrandom, it is important to understand the manner in which those species that we anticipate losing interact with other species to affect ecosystem function. We tested whether litter species diversity, measured as richness and composition, affects breakdown dynamics in a detritus-based stream. Using full-factorial analyses of single- and mixed-species leaf packs (15 possible combinations of four dominant litter species; red maple [Acer rubrum], tulip poplar [Liriodendron tulipifera], chestnut oak [Quercus prinus], and rhododendron [Rhododendron maximum]), we tested for single-species presence/absence (additive) or species interaction (nonadditive) effects on leaf pack breakdown rates, changes in litter chemistry, and microbial and macroinvertebrate biomass. Overall, we found significant nonadditive effects of litter species diversity on leaf pack breakdown rates, which were explained both by richness and composition. Leaf packs containing higher litter species richness had faster breakdown rates, and antagonistic effects of litter species composition were observed when any two or three of the four litter species were mixed. Less-consistent results were obtained with respect to changes in litter chemistry and microbial and macroinvertebrate biomass. Our results suggest that loss of litter species diversity will decrease species interactions involved in regulating ecosystem function. To that end, loss of species such as eastern hemlock (Tsuga canadensis) accompanied by predicted changes in riparian tree species composition in the southeastern United States could have nonadditive effects on litter breakdown at the landscape scale. PMID:17536403

  8. Energetic considerations and habitat quality for elk in arid grasslands and coniferous forests

    SciTech Connect

    McCorquodale, S.M. )

    1991-04-01

    The author used static modeling to explore the recent success of elk (Cervus elaphus) colonizing the arid shrub-steppe of Washington. Forage-based estimates of metabolizable energy available to elk in the shrub-steppe were compared to energy available in 2 mesic forest communities that historically have served as more typical summer elk habitat. Although precipitation and primary productivity were substantially lower in the shrub-steppe, the estimated calories available in shrub-steppe forage over a 300-km{sup 2} area were 271 and 86%, respectively, of lodgepole pine (Pinus contorta) and cedar-hemlock (Thuja-Tsuga) forests of similar size. Low intercommunity variability in forage production, lack of a significant nonforage overstory, and the large size and relative abundance of foraging areas in the shrub-steppe mitigated reduced primary production. In the shrub-steppe, 92% of the habitat represented potential foraging habitat as determined by minimum forage biomass, whereas only 10 and 40% of the forested habitats, respectively, could be considered prime foraging areas. Whereas forage energy was concentrated in openings within conifer forests, it was more uniformly dispersed over the habitat mosaic in the shrub-steppe. These results provide a bioenergetic framework for understanding the recent success of elk colonizing the arid shrub-steppe of Washington and are consistent with observed patterns of movement and habitat use for elk in shrub-steppe habitat.

  9. Patterns and Impacts of millennial-scale hydroclimatic change in North American during the Holocene

    NASA Astrophysics Data System (ADS)

    Shuman, B. N.

    2012-12-01

    A new database of >100 lake-level reconstructions spanning the Holocene from the United States and Canada reveals that long-term patterns of hydroclimatic change in the mid-latitudes were punctuated by a series of abrupt events, particularly at ca. 8 and 5.5 ka. New detailed reconstructions from the Rocky Mountains and the northeast U.S. show that the abrupt changes produced important changes in the gradient of moisture availability across the continent with the mid-continent drying and the Atlantic coast becoming wet at ca 8 ka, and then a reversal of this pattern at 5.5 ka. Both changes are associated with important abrupt changes in North American vegetation, including abrupt shifts in the boundaries of the Great Plains grasslands and including the classic collapse of eastern hemlock (Tsuga) species. Regression analyses indicate that the area of the Laurentide Ice Sheet and Atlantic sea surface temperatures drove the abrupt changes. Archeological data also reveal societal importance of the hydroclimatic changes, which included probably severe reductions in mid-continent river flows.

  10. Role of Nurse Logs in Forest Expansion at Timberline

    NASA Astrophysics Data System (ADS)

    Johnson, A. C.; Yeakley, A.

    2008-12-01

    Nurselogs, known to be key sites of forest regeneration in lower elevation temperate forests, may be important sites for seedling establishment at expanding timberline forests. To determine factors associated with seedling establishment and survival on nurselogs at timberline, fourteen sites, located across a precipitation gradient in the Washington North Cascades Mountains, were examined. Site attributes including seedling type and height, disturbance process introducing downed wood, wood decay type, shading, slope gradient, aspect, and temperature and water content of wood and adjacent soil were determined along 60 m long transects. Nurselogs were found at 13 out of 14 sites; sites typically associated with greater than 80% shade and downed wood having a high level of wood decay. Downed wood serving as nurselogs originated from blowdown, snow avalanches, and forest fires. In total, 46 of 136 downed wood pieces observed served as nurselogs. Seedlings on nurselogs included mountain hemlock (Tsuga mertensiana), Pacific silver fir (Abies amabilis), yellow cedar (Chamaecyparis nootkatensis), subalpine fir (Abies lasiocarpa), Engelmann spruce (Picea engelmannii), and western larch (Larix occidentalis). Nurselogs had significantly higher temperatures (p = 0.015) and higher moisture contents (p = 0.019) than the adjacent soil. Per equal volumes weighed, nurselogs had on average of 23.8 g more water than the adjacent soil. Given predictions of climate warming and associated summer drought conditions in Pacific Northwest forests, the moisture provided by nurselogs may be integral for conifer survival and subsequent timberline expansion in some landscapes.

  11. The contribution of dynamic changes in photosynthesis to shade tolerance of two conifer species.

    PubMed

    Ma, Ziyu; Behling, Shawn; Ford, E David

    2014-07-01

    Generally 'shade tolerance' refers to the capacity of a plant to exist at low light levels but characteristics of shade can vary and must be taken into account in defining the term. We studied Abies amabilis Dougl. ex J.Forbes and Tsuga heterophylla (Raf.) Sarg. under a forest canopy in the northwest of the Olympic Peninsula, USA, which has low annual sunshine hours and frequent overcast days. Using BF3 sunshine sensors, we surveyed diffuse and total light received by saplings growing under a range of canopy openness up to 30%. We measured variation in photosynthetic capacity over the growing season and within days and estimated photosynthesis induction in relation to ambient light. Three components of shade tolerance are associated with variation in light climate: (i) Total light on the floor of an 88-year stand of naturally regenerated T. heterophylla was greater on overcast than clear days. Light on overcast days varied throughout the day sometimes with a cyclical pattern. (ii) Photosynthetic capacity, Amax, varied both through the growing season and within days. Amax was generally greater in the latter part of the growing season, being limited by temperature and stomatal conductance, gs, at times during the early part. Saplings in more shaded areas had lower Amax and in the latter part of the growing season Amax was found to decline from mid-afternoon. (iii) Two patterns of photosynthesis induction to increased light were found. In a mean ambient light of 139 μmol m(-2) s(-1), induction had a curvilinear response to a step increase in light with a mean time constant, τ, of 112.3 s. In a mean ambient light of 74 μmol m(-2) s(-1), induction had a two-part increase: one with τ1 of 11.3 s and the other with τ2 of 184.0 s. These are the smallest published values of τ to date. (iv) Both variation in photosynthetic capacity and induction are components of shade tolerance where light varies over time. Amax acclimates to seasonal and diurnal changes in light and varies between microenvironments. The rapid induction processes can cause a rapid response of photosynthesis to changes in diffuse or direct light. PMID:25070983

  12. Nitrogen uptake in riparian plant communities across a sharp ecological boundary of salmon density

    PubMed Central

    Mathewson, DD; Hocking, MD; Reimchen, TE

    2003-01-01

    Background Recent studies of anadromous salmon (Oncorhynchus spp.) on the Pacific Coast of North America indicate an important and previously unrecognized role of salmonid nutrients to terrestrial biota. However, the extent of this uptake by primary producers and consumers and the influences on community structure remain poorly described. We examine here the contribution of salmon nutrients to multiple taxa of riparian vegetation (Blechnum spicant, Menziesii ferruginea, Oplopanax horridus, Rubus spectabilis, Vaccinium alaskaense, V. parvifolium, Tsuga heterophylla) and measure foliar δ15N, total %N and plant community structure at two geographically separated watersheds in coastal British Columbia. To reduce potentially confounding effects of precipitation, substrate and other abiotic variables, we made comparisons across a sharp ecological boundary of salmon density that resulted from a waterfall barrier to salmon migration. Results δ15N and %N in foliage, and %cover of soil nitrogen indicators differed across the waterfall barrier to salmon at each watershed. δ15N values were enriched by 1.4‰ to 9.0‰ below the falls depending on species and watershed, providing a relative contribution of marine-derived nitrogen (MDN) to vegetation of 10% to 60%. %N in foliar tissues was slightly higher below the falls, with the majority of variance occurring between vegetation species. Community structure also differed with higher incidence of nitrogen-rich soil indicator species below the waterfalls. Conclusions Measures of δ15N, %N and vegetation cover indicate a consistent difference in the riparian community across a sharp ecological boundary of salmon density. The additional N source that salmon provide to nitrogen-limited habitats appears to have significant impacts on the N budget of riparian vegetation, which may increase primary productivity, and result in community shifts between sites with and without salmon access. This, in turn, may have cascading ecosystem effects in forests adjacent to salmon streams. PMID:12729462

  13. Dynamics of water transport and storage in conifers studied with deuterium and heat tracing techniques.

    PubMed

    Meinzer, F C; Brooks, J R; Domec, J C; Gartner, B L; Warren, J M; Woodruff, D R; Bible, K; Shaw, D C

    2006-01-01

    The volume and complexity of their vascular systems make the dynamics of long-distance water transport in large trees difficult to study. We used heat and deuterated water (D2)) as tracers to characterize whole-tree water transport and storage properties in individual trees belonging to the coniferous species Pseudotsuga menziesii (Mirb.) Franco and Tsuga heterophylla (Raf.) Sarg. The trees used in this study spanned a broad range of height (13.5-58 m) and diameter (0.14-1.43 m). Sap flow was monitored continuously with heat dissipation probes near the base of the trunk prior to, during and following injection of D2O. The transit time for D2O transport from the base of the trunk to the upper crown and the tracer residence time were determined by measuring hydrogen isotope ratios in water extracted from leaves sampled at regular intervals. Transit times for arrival of D2O in the upper crown ranged from 2.5 to 21 d and residence times ranged from 36 to 79 d. Estimates of maximum sap velocity derived from tracer transit times and path length ranged from 2.4 to 5.4 m d(-1). Tracer residence time and half-life increased as tree diameter increased, independent of species. Species-independent scaling of tracer velocity with sapwood-specific conductivity was also observed. When data from this study were combined with similar data from an earlier study of four tropical angiosperm trees, species-independent scaling of tracer velocity and residence time with sapwood hydraulic capacitance was observed. Sapwood capacitance is an intrinsic tissue-level property that appears to govern whole-tree water transport in a similar manner among both tracheid- and vessel-bearing species. PMID:17086757

  14. The Heidelberg Basin Drilling Project - Sedimentology and Stratigraphy of the Quaternary succession

    NASA Astrophysics Data System (ADS)

    Ellwanger, Dietrich; Gabriel, Gerald; Hahne, Jürgen; Hoselmann, Christian; Menzies, John; Simon, Theo; Weidenfeller, Michael; Wielandt-Schuster, Ulrike

    2010-05-01

    Within the context of the Heidelberg Basin Drilling Project (Gabriel et al. 2008), a detailed sediment succession is presented here based upon deep drillings taken at Heidelberg UniNord and Mannheim Käfertal. Sediment structures, and micromorphological and pollen analyses were conducted and used to reconsider some of the climate transitions within the lower Pleistocene. A new and novel scenario is postulated regarding the preservation of Quaternary sediment packages within the Cenozoic Graben environment of the Heidelberg basin. The palynological evidence comprises the periods of warm climate of the Holsteinian (mainly Abies (fir), some Fagus (beech), Pterocarya & Azolla); the Cromerian (Pinus-Picea-QM (pine-spruce-QM)); the Bavelian (Abies, Tsuga (hemlock fir), QM & phases of increased NAP including Pinus); the Waalian (Abies, Tsuga, QM); and the Tiglian (Fagus & early Pleistocene taxa especially Sciadopytis, downward increasing Tertiary taxa). The sediment package was studied both macroscopically and microscopically. Both techniques provide evidence of fluvial, lacustrine and mass movement sedimentary processes. Some include evidence of periglacial processes (silt droplets within fine grained sands indicative of frozen ground conditions). The periglacial structures are often, not always, accompanied by pollen spectra dominated by pine and NAP. E.g. the Tiglian part of the succession shows periglacial sediment structures at its base and top but not in its middle sections. I.e. it appears not as a series of warm and cold phases but rather as a constant warm period with warm-cold-alternations at its bottom and top. All results illustrate sediment preservation in the Heidelberg basin almost throughout the Quaternary. This may be due to tectonic subsidence, but also to compaction by sediment loading of underlying fine sediments (Oligocene to Quaternary) leading to incomplete but virtually continuous sediment preservation (Tanner et al. 2009). References Gabriel, G., Ellwanger, D., Hoselmann, C. & Weidenfeller, M. (2008): The Heidelberg Basin Drilling Project. - Eiszeitalter u. Gegenwart (Quaternary Science Journal), 57, 3-4, 253-260, Hannover. Tanner, D.C., Martini, N., Buness, H. & Krawczyk, C.M. (2009): The 3D Geometry of the Quaternary and Tertiary strata in the Heidelberg Basin, as defined by reflection seismics. - DGG Tagung, Dresden, 30.9-02.10.09, Schriftenreihe der Deutschen Gesellschaft für Geowissenschaften, 63, 58.

  15. Fruiting body and soil rDNA sampling detects complementary assemblage of Agaricomycotina (Basidiomycota, Fungi) in a hemlock-dominated forest plot in southern Ontario.

    PubMed

    Porter, Teresita M; Skillman, Jane E; Moncalvo, Jean-Marc

    2008-07-01

    This is the first study to assess the diversity and community structure of the Agaricomycotina in an ectotrophic forest using above-ground fruiting body surveys as well as soil rDNA sampling. We recovered 132 molecular operational taxonomic units, or 'species', from fruiting bodies and 66 from soil, with little overlap. Fruiting body sampling primarily recovered fungi from the Agaricales, Russulales, Boletales and Cantharellales. Many of these species are ectomycorrhizal and form large fruiting bodies. Soil rDNA sampling recovered fungi from these groups in addition to taxa overlooked during the fruiting body survey from the Atheliales, Trechisporales and Sebacinales. Species from these groups form inconspicuous, resupinate and corticioid fruiting bodies. Soil sampling also detected fungi from the Hysterangiales that form fruiting bodies underground. Generally, fruiting body and soil rDNA samples recover a largely different assemblage of fungi at the species level; however, both methods identify the same dominant fungi at the genus-order level and ectomycorrhizal fungi as the prevailing type. Richness, abundance, and phylogenetic diversity (PD) identify the Agaricales as the dominant fungal group above- and below-ground; however, we find that molecularly highly divergent lineages may account for a greater proportion of total diversity using the PD measure compared with richness and abundance. Unless an exhaustive inventory is required, the rapidity and versatility of DNA-based sampling may be sufficient for a first assessment of the dominant taxonomic and ecological groups of fungi in forest soil. PMID:18494767

  16. AmeriFlux US-Bar Bartlett Experimental Forest

    DOE Data Explorer

    Richardson, Andrew [Harvard University

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Bar Bartlett Experimental Forest. Site Description - The Bartlett Experimental Forest (448170 N, 71830 W) is located within the White Mountains National Forest in north-central New Hampshire, USA. The 1050 ha forest extends across an elevational range from 200 to 900 m a.s.l. It was established in 1931 and is managed by the USDA Forest Service Northeastern Research Station in Durham, NH. The climate is humid continental with short, cool summers (mean July temperature, 19.8C) and long, cold winters (mean January temperature, 9.8C). Annual precipitation averages 130 cm and is distributed evenly throughout the year. Soils are developed from glacial till and are predominantly shallow, well-drained spodosols. At lowto mid-elevation, vegetation is dominated by northern hardwoods (American beech, Fagus grandifolia; sugar maple, Acer saccharum; yellow birch, Betula alleghaniensis; with some red maple, Acer rubrum and paper birch, Betula papyrifera). Conifers (eastern hemlock, Tsuga canadensis; eastern white pine, Pinus strobus; red spruce, Picea rubens) are occasionally found intermixed with the more abundant deciduous species but are generally confined to the highest (red spruce) and lowest (hemlock and pine) elevations. In 2003, the site was adopted as a NASA North American Carbon Program (NACP) Tier-2 field research and validation site. A 26.5 m high tower was installed in a low-elevation northern hardwood stand in November, 2003, for the purpose of making eddy covariance measurements of the forest–atmosphere exchange of CO2, H2O and radiant energy. Continuous flux and meteorological measurements began in January, 2004, and are ongoing. Average canopy height in the vicinity of the tower is approximately 20–22 m. In the tower footprint, the forest is predominantly classified into red maple, sugar maple, and American beech forest types. Leaf area index in the vicinity of the tower is 3.6 as measured by seasonal litterfall collection, and 4.5 as measured by the optically based Li-Cor LAI-2000 instrument. Further site information: http://www.fs.fed.us/ne/durham/4155/bartlett.htm

  17. Calibrating abundance indices with population size estimators of red back salamanders (Plethodon cinereus) in a New England forest

    PubMed Central

    Ellison, Aaron M.; Jackson, Scott

    2015-01-01

    Herpetologists and conservation biologists frequently use convenient and cost-effective, but less accurate, abundance indices (e.g., number of individuals collected under artificial cover boards or during natural objects surveys) in lieu of more accurate, but costly and destructive, population size estimators to detect and monitor size, state, and trends of amphibian populations. Although there are advantages and disadvantages to each approach, reliable use of abundance indices requires that they be calibrated with accurate population estimators. Such calibrations, however, are rare. The red back salamander, Plethodon cinereus, is an ecologically useful indicator species of forest dynamics, and accurate calibration of indices of salamander abundance could increase the reliability of abundance indices used in monitoring programs. We calibrated abundance indices derived from surveys of P. cinereus under artificial cover boards or natural objects with a more accurate estimator of their population size in a New England forest. Average densities/m2 and capture probabilities of P. cinereus under natural objects or cover boards in independent, replicate sites at the Harvard Forest (Petersham, Massachusetts, USA) were similar in stands dominated by Tsuga canadensis (eastern hemlock) and deciduous hardwood species (predominantly Quercus rubra [red oak] and Acer rubrum [red maple]). The abundance index based on salamanders surveyed under natural objects was significantly associated with density estimates of P. cinereus derived from depletion (removal) surveys, but underestimated true density by 50%. In contrast, the abundance index based on cover-board surveys overestimated true density by a factor of 8 and the association between the cover-board index and the density estimates was not statistically significant. We conclude that when calibrated and used appropriately, some abundance indices may provide cost-effective and reliable measures of P. cinereus abundance that could be used in conservation assessments and long-term monitoring at Harvard Forest and other northeastern USA forests. PMID:26020008

  18. Wood colors and their coloring matters: a review.

    PubMed

    Yazaki, Yoshikazu

    2015-03-01

    A number of colored specialty woods, such as ebony, rosewood, mahogany and amboyna, and commercially important woods, such as morus, logwood, Brazilwood, Japanese yellowwood, blackwood, kwila, red beech and myrtle beech, exhibit a wide range of colors from black, violet, dark red, reddish brown, to pale yellow. These colors are not only due to colored pigments contained in extractives from those woods but also to insoluble polymers. Wood and bark from many species of both hardwood and softwood trees contain many types of flavonoid compounds. Research on flavonoids has been conducted mainly from two points of view. The first is chemotaxonomy with flavonoid compounds as taxonomic markers, and the second relates to the utilization of woods for pulp and paper and the use of tannins from bark for wood adhesives. Most chemotaxonomic studies have been conducted on flavonoids in the extracts from softwoods such as Podocarpus, Pinus, Pseudotsuga, Larix, Taxus, Libocedrus, Tsuja, Taxodium, Sequoia, Cedrus, Tsuga, Abies and Picea. Hardwood chemotaxonomic studies include those on Prunus and Eucalyptus species. Studies on flavonoids in pulp and paper production were conducted on Eucalyptus woods in Australia and woods from Douglas fir in the USA and larch in Japan. Flavonoids as tannin resources from black wattle tannin and quebracho tannin have been used commercially as wood adhesives. Flavonoids in the bark from radiata pine and southern pine, from western and eastern hemlock, southern red oak and Quercus dentata are also discussed. In addition, the distribution of flavonoids among tree species is described, as is the first isolation of rare procyanidin glycosides in nature. PMID:25924540

  19. Calibrating abundance indices with population size estimators of red back salamanders (Plethodon cinereus) in a New England forest.

    PubMed

    Siddig, Ahmed A; Ellison, Aaron M; Jackson, Scott

    2015-01-01

    Herpetologists and conservation biologists frequently use convenient and cost-effective, but less accurate, abundance indices (e.g., number of individuals collected under artificial cover boards or during natural objects surveys) in lieu of more accurate, but costly and destructive, population size estimators to detect and monitor size, state, and trends of amphibian populations. Although there are advantages and disadvantages to each approach, reliable use of abundance indices requires that they be calibrated with accurate population estimators. Such calibrations, however, are rare. The red back salamander, Plethodon cinereus, is an ecologically useful indicator species of forest dynamics, and accurate calibration of indices of salamander abundance could increase the reliability of abundance indices used in monitoring programs. We calibrated abundance indices derived from surveys of P. cinereus under artificial cover boards or natural objects with a more accurate estimator of their population size in a New England forest. Average densities/m(2) and capture probabilities of P. cinereus under natural objects or cover boards in independent, replicate sites at the Harvard Forest (Petersham, Massachusetts, USA) were similar in stands dominated by Tsuga canadensis (eastern hemlock) and deciduous hardwood species (predominantly Quercus rubra [red oak] and Acer rubrum [red maple]). The abundance index based on salamanders surveyed under natural objects was significantly associated with density estimates of P. cinereus derived from depletion (removal) surveys, but underestimated true density by 50%. In contrast, the abundance index based on cover-board surveys overestimated true density by a factor of 8 and the association between the cover-board index and the density estimates was not statistically significant. We conclude that when calibrated and used appropriately, some abundance indices may provide cost-effective and reliable measures of P. cinereus abundance that could be used in conservation assessments and long-term monitoring at Harvard Forest and other northeastern USA forests. PMID:26020008

  20. Dendrogeomorphic Assessment of the Rattlesnake Gulf Landslide in the Tully Valley, Onondaga County, New York

    USGS Publications Warehouse

    Tamulonis, Kathryn L.; Kappel, William M.

    2009-01-01

    Dendrogeomorphic techniques were used to assess soil movement within the Rattlesnake Gulf landslide in the Tully Valley of central New York during the last century. This landslide is a postglacial, slow-moving earth slide that covers 23 acres and consists primarily of rotated, laminated, glaciolacustrine silt and clay. Sixty-two increment cores were obtained from 30 hemlock (Tsuga canadensis) trees across the active part of the landslide and from 3 control sites to interpret the soil-displacement history. Annual growth rings were measured and reaction wood was identified to indicate years in which ring growth changed from concentric to eccentric, on the premise that soil movement triggered compensatory growth in displaced trees. These data provided a basis for an 'event index' to identify years of landslide activity over the 108 years of record represented by the oldest trees. Event-index values and total annual precipitation increased during this time, but years with sudden event-index increases did not necessarily correspond to years with above-average precipitation. Multiple-regression and residual-values analyses indicated a possible correlation between precipitation and movement within the landslide and a possible cyclic (decades-long) tree-ring response to displacement within the landslide area from the toe upward to, and possibly beyond, previously formed landslide features. The soil movement is triggered by a sequence of factors that include (1) periods of several months with below-average precipitation followed by persistent above-average precipitation, (2) the attendant increase in streamflow, which erodes the landslide toe and results in an upslope propagation of slumping, and (3) the harvesting of mature trees within this landslide during the last century and continuing to the present.

  1. Plant and Soil Natural Abundance delta-15N: Indicators of Nitrogen Cycling in the Catskill Mountains, New York, USA

    NASA Astrophysics Data System (ADS)

    Templer, P. H.; Lovett, G. M.; Weathers, K.; Arthur, M. A.

    2002-12-01

    We examined the potential use of natural abundance 15N of plants and soils as an indicator of forest nitrogen (N) cycling rates within the Catskill Mountains, NY. These watersheds receive among the highest rates of N deposition in the northeastern United States and are beginning to show signs of N saturation. Many studies have shown a link between increased N cycling rates and 15N enrichment of soil and plant pools. Faster rates of N cycling processes, especially nitrification, lead to fractionation of 14/15N, creating N products that are relatively depleted in 15N. This can lead to enrichment of soil pools, as lighter 14N is lost from the system via leaching or denitrification. Plant N pools can become increasingly enriched as they take up 15N-enriched soil N. Despite similar amounts of N deposition across the Catskill Mountains, forests dominated by different tree species appear to vary in the amount of N retained or lost to nearby streams. To determine if plant and soil 15N could be used as indicators of N cycling rates, we collected foliage, wood, litterfall, organic and mineral soil, and fine roots from single species stands of American beech (Fagus grandifolia), eastern hemlock (Tsuga canadensis), red oak (Quercus rubra), and sugar maple (Acer saccharum). Fine roots and soil 15N were highest within sugar maple stands (p<0.05). Sugar maple soils also had the highest rates of net nitrification and N leaching. Therefore, soil 15N appears to correlate with forest N retention and loss. However, 15N enrichment was highest within foliage, litterfall and wood of beech trees (p<0.05). The decoupling between foliage 15N and N cycling, as well as between 15N of foliage and fine roots, illustrates that it may not be possible to use a single plant pool as an indicator of N cycling rates.

  2. Forest responses to late Holocene climate change in north-central Wisconsin: a high- resolution study from Hell's Kitchen Lake.

    NASA Astrophysics Data System (ADS)

    Urban, M. A.; Booth, R. K.; Jackson, S. T.; Minckley, T. A.

    2007-12-01

    Forest dynamics at centennial to millennial timescales can be identified using paleoecological records with high spatial, temporal, and taxonomic resolution. These dynamics are linked to climate changes by comparing the paleoecological records with independent paleoclimate records of complementary sensitivity and temporal resolution. We analyzed plant macrofossils at contiguous 1cm intervals (representing 5 to 35 yr/cm) from late Holocene sediments of Hell's Kitchen Lake (3 ha) in north-central Wisconsin. Most of the plant macrofossils derive from trees growing on the slopes directly adjacent to the lake, and were identified to the species. We also analyzed pollen at an approximately100 year resolution to provide a regionally integrated record of forest composition. We then compared the macrofossil and pollen records with independent records of climate change in the region, particularly paleohydrological records from kettle bogs. The most notable feature of the late Holocene record occurs between 2300-2000 cal yr BP. During this period yellow birch (Betula alleghaniensis) macrofossils first appear in the record, along with a corresponding increase in pollen percentages. Hemlock (Tsuga canadensis) macrofossils and pollen also show a marked increase at this time. These changes coincide with a major transition towards wetter conditions recorded in the testate amoebae record of Hornet Bog (~200km northwest) and in a number of other kettle bog records from the region. Directly following this transition, tamarack (Larix laricina) and Sphagnum macrofossils at Hell's Kitchen Lake increase dramatically, likely representing the initiation of bog-mat growth along the southwest margin of the lake during the wet period. . We are continuing our high-resolution sampling downcore at Hell's Kitchen Lake. This will permit us to examine additional ecologic and climatic events in the early and mid-Holocene.

  3. Element accumulation patterns of deciduous and evergreen tree seedlings on acid soils: implications for sensitivity to manganese toxicity.

    PubMed

    St Clair, Samuel B; Lynch, Jonathan P

    2005-01-01

    Foliar nutrient imbalances, including the hyperaccumulation of manganese (Mn), are correlated with symptoms of declining health in sensitive tree species growing on acidic forest soils. The objectives of this study were to: (1) compare foliar nutrient accumulation patterns of six deciduous (sugar maple (Acer saccharum Marsh.), red maple (Acer rubrum L.), red oak (Quercus rubra L.), white oak (Quercus alba L.), black cherry (Prunus serotina Ehrh.) and white ash (Fraxinus americana L.)) and three evergreen (eastern hemlock (Tsuga canadensis L.), white pine (Pinus strobus L.) and white spruce (Picea glauca (Moench) Voss.)) tree species growing on acidic forest soils; and (2) examine how leaf phenology and other traits that distinguish evergreen and deciduous tree species influence foliar Mn accumulation rates and sensitivity to excess Mn. For the first objective, leaf samples of seedlings from five acidic, non-glaciated field sites on Pennsylvania's Allegheny Plateau were collected and analyzed for leaf element concentrations. In a second study, we examined growth and photosynthetic responses of seedlings exposed to excess Mn in sand culture. In field samples, Mn in deciduous foliage hyperaccumulated to concentrations more than twice as high as those found in evergreen needles. Among species, sugar maple was the most sensitive to excess Mn based on growth and photosynthetic measurements. Photosynthesis in red maple and red oak was also sensitive to excess Mn, whereas white oak, black cherry, white ash and the three evergreen species were tolerant of excess Mn. Among the nine species, relative rates of photosynthesis were negatively correlated with foliar Mn concentrations, suggesting that photosynthetic sensitivity to Mn is a function of its rate of accumulation in seedling foliage. PMID:15519989

  4. 12,000-year record of forest history from Cahaba Pond, St. Clair County, Alabama

    SciTech Connect

    Delcourt, H.R.; Delcourt, P.A.; Spiker, E.C.

    1983-01-01

    A 650-cm sediment sequence from Cahaba Pond, St. Clair County, Alabama, spans the past 12,000 y and has yielded a pollen and plant-macrofossil record indicating major changes in forest composition during the Holocene interglacial. Both pollen and plant macrofossils from sediments of this 0.2-ha pond primarily reflect changes in local and extralocal forests within the surrounding watershed. Four distinct pollen assemblage zones were recognized: a Fagus-Ostrya zone from 12,000 to 10,200 BP, a Pinus-Magnolia zone from 10,200 to 10,000 BP, a Quercus-Carya zone from 10,000 to 8400 BP, and a Nyssa-Pinus zone from 8400 BP to the present. Forests of the early Holocene (12,000 to 10,000 BP) were mesic and predominantly composed of broadleaved deciduous trees, dominated by beech (Fagus grandifolia). Atlantic white cedar (Chamaecyparis thyoides), today a coastal species, extended inland to St. Clair County during the early Holocene, Eastern white pine (Pinus strobus), hemlock (Tsuga), striped maple (Acer pensylvanicum), and mountain maple (Acer spicatum), today rare or absent in Alabama, extended southward of their present ranges into central Alabama 10,000 y ago. After 10,000 BP, forests became more xeric, with oaks and hickories predominant. After 8400 BP, black gum (Nyssa sylvatica), southern pines (Diploxylon Pinus), red maple (Acer rubrum), sweetgum (Liquidambar styraciflua), buttonbush (Cephalanthus occidentalis), and other elements of the modern flora became established locally. Water levels in the pond became higher, and sedimentation rate diminished. An increase in effective precipitation in the late Holocene reflects in the establishment of the modern atmospheric circulation patterns.

  5. Understory vegetation in old and young Douglas-fir forests of western Oregon

    USGS Publications Warehouse

    Bailey, J.D.; Mayrsohn, C.; Doescher, P.S.; St., Pierre, E.; Tappeiner, J.C.

    1998-01-01

    We studied understory composition in thinned and unthinned Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)/western hemlock (Tsuga heterophylIa (Raf.) Sarg.) stands on 28 sites in western Oregon. These stands had regenerated naturally after timber harvest, 40-70 years before thinning. Commercial thinning had occurred 10-24 years previously, with 8-60% of the volume removed from below with the intent to homogenize spacing among trees. Undisturbed old-growth Douglas-fir stands were present for comparison on 18 of these sites. Total herbaceous cover was greater in thinned 1125% cover) stands than in unthinned (13% cover) or old-growth (15% cover) stands. Species richness was also greater in thinned (137) than in unthinned (114) and old-growth (91) stands (P=0.05). Part of the increased richness was caused by the presence of exotic species in thinned stands, but there were also more native grass and nitrogen-fixing species in thinned stands than in unthinned or oldgrowth stands. Groups of species differed among stand-types. For example, the frequency of tall cordate-leaved species was greater in old-growth stands (P=O.009), but their relative cover was different only between old-growth and unthinned stands (P=0.08). Both the cover and frequency of grasses and sedges in thinned stands were greater than in unthinned or old-growth stands (P<0.002). Ordination of shrub cover showed differences among old-growth and unthinned stands compared to thinned stands, mainly because of the amount of Gaultheria shallon Pursh and Polystichum munitum (Kaulf.) Presl in heavily thinned stands. Ordination of herbaceous community data showed that there were much stronger differences among sites than among stand-types. The lack of difference among stand-types demonstrates the resiliency of herbaceous communities to disturbance associated with past and current forest management.

  6. Effects of forest die-off on hydrologic processes in southern Appalachian forests

    NASA Astrophysics Data System (ADS)

    Vose, J.; Ford, C. R.

    2011-12-01

    Forests in the southern Appalachian region of the eastern U.S. have been impacted by numerous disturbances over the past century. Many of these disturbances have resulted in non-random species losses. For example, in the early 1900s, American chestnut (Castenea dentata) was decimated by the chestnut blight. Severe droughts in the 1980s and 1990s resulted in significant southern pine beetle (Dendroctonus frontalis, SPB) outbreaks; and, most of the native pines (Pinus rigida) were killed. These same droughts resulted in a pulse of mortality of older red oaks and extensive SPB infestation of white pine (Pinus strobus) plantations. In the 2000s, the introduction of the hemlock woolly adelgid (HWA) resulted in widespread mortality of eastern hemlock (Tsuga canadensis). Linking hydrologic responses to partial or complete changes in forest conditions due to die-off is especially challenging in the eastern U.S. because high vegetation diversity and substantial differences in tree-level water use makes it difficult to generalize or predict responses. Gauged watersheds and sapflow monitoring across multiple tree species at the Coweeta Hydrologic Laboratory in western NC provides a unique opportunity to quantify the impacts of large-scale forest die-off on hydrologic processes. Here, we provide three examples of our efforts to quantify and predict impacts. First, we analyzed long-term streamflow data from WS17, a 53 year old white pine plantation, where approximately 15% of the watershed was killed by SPB in the late 1990s. Second, we examined the effects of losing an individual species (i.e., loss of eastern hemlock from HWA) using sapflow, long-term permanent plot data, and models to scale from the individual tree to the watershed. Third, sapflow data from 11 forest canopy species were used to evaluate the potential impacts of losses of individual species on stand transpiration. Annual streamflow responses are exponentially related to decreases in forest cover (e.g., from forest cutting or die-off). First year responses in streamflow after a 15% reduction in forest cover are small: less than 30 mm yr-1. However, we observed a significant increase in low flows in the years following pine mortality, especially in the winter. Using sapflow measurements and scaling, we predict that HWA mortality would reduce annual transpiration by 10%, and winter and spring transpiration by 30%. Finally, analyses of long-term sapflow measurements across a range of species suggest a wide variation in potential responses to the loss of individual species or species groups. For example, growing season water use is lowest for oaks (Quercus rubra and Quercus prinus) and highest for yellow poplar (Liriodendron tulipifera), suggesting that the effects of forest die-off on hydrologic responses are dependent on species composition.

  7. 77 FR 30500 - Foreign-Trade Zones 140 and 78, Applications for Subzone Authority, Dow Corning Corporation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-23

    ... facility in Midland, Michigan (76 FR 63282- 63283, 10/12/2011), at the Hemlock Semiconductor Corporation facility in Hemlock, Michigan (76 FR 63282, 10/12/2011) and at the Hemlock Semiconductor, L.L.C. facility in Clarksville, Tennessee (76 FR 63281- 63282, 10/12/2011) are being reopened. Additional...

  8. Variation in forest biomass change highlights regional differences in forest succession in the Pacific Northwest, USA.

    NASA Astrophysics Data System (ADS)

    Bell, D. M.; Gray, A. N.

    2014-12-01

    Forest successional theory describes the changes in forest biomass and community composition from forest establishment to climax communities, but the drivers of succession are still widely debated. For example, successional models have related biomass and community change to stand age, species rarity within the community, small-scale disturbance, or the ability of species to survive under low resource conditions. The degree to which these drivers might vary regionally limits our ability to model and predict ecosystem change. Our objective was to assess whether forest successional theory explains observed changes in species biomass and community composition across forests of the U. S. Pacific Northwest. Using remeasurements of 9,700 Current Vegetation Survey (CVS) National Forest inventory plots primarily in Oregon and Washington, we quantified the effects of forest stand age, community composition, disturbance, and moisture (i.e., topography and climate) on changes in species-specific proportional live biomass (ΔB) and species dominance (ΔD). We focused on differences in forest successional patterns in two vegetation zones: the Tsuga heterophylla (TSHE) zone, found at low elevations on the wet, west side of the Cascade Mountains; and the Abies concolor (ABCO) zone, found at mid-elevations on the dry, east side of the Cascade Mountains. Preliminary results indicate that the regional differences in tree species biomass change and dominance appear to be related to responses to climate and disturbance. Strong positive effects of cover change on ΔB were observed in the drier ABCO zone, but not the wetter TSHE zone. ΔB and ΔD were more often sensitive to precipitation and topographic position in the ABCO zone. In both regions, we found that ΔB was strongly negatively related to species biomass and stand age while ΔD was strongly negatively related to relative density, highlighting the importance of both age and community in shaping succession. Given that the importance of different forest successional processes in shaping ecosystem change varied regionally, this work provides valuable insights into potential risks of changing climate and disturbance regimes to species persistence and ecosystem stability across forests of the U.S. Pacific Northwest.

  9. Late-Quaternary paleovegetation, paleoclimate and fire disturbance records from subalpine sites on Vancouver Island, British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Fitton, R. J.; Brown, K. J.; Hebda, R. J.

    2003-04-01

    Analyses of pollen, macrofossils and charcoal from subalpine lakes provide insight into past climatic changes as well as local factors affecting the sites, especially since steep precipitation and temperature gradients typify mountainous regions. Lake and bog cores collected from three sites on southern and central Vancouver Island (Porphyry and Walker lakes and Harris Lake Ridge Bog) were analysed for pollen, macrofossils and charcoal and the resulting data were used to reveal post-glacial changes in vegetation, climate and fire disturbance. The paleovegetation, paleoclimate, and fire disturbance records from Porphyry and Walker Lakes parallel those from low elevations during the post-glacial interval, suggesting that these sites responded strongly to regional forcing and were somewhat less sensitive to local forcing. Of notable interest is the upward migration of lowland taxa to these lakes during the warm dry early-Holocene. A change to cooler and moister conditions in the mid- and late-Holocene is subsequently characterised by downslope movement of species ranges and the establishment of modern subalpine communities. In contrast, Harris Lake Ridge Bog from central Vancouver Island has a more complicated history that exhibits strong local and regional influences. This site is less similar to lowland records despite a relatively similar ecotonal position as the other two sites. In the early-Holocene upslope movement of low elevation species is less obvious than at Porphyry and Walker lakes. In the mid- and late-Holocene forest composition changed around Harris Lake Ridge Bog as conditions cooled and moistened and taxa better suited to nutrient poor soils, such as Tsuga mertensiana and T. heterophylla expanded. At the same time, there is evidence to suggest that local switches between forest and heather communities were initiated by fire. Consequently, records from subalpine wetlands may provide more potential for detailed reconstruction of local in-stand vegetation dynamics than those from lakes. Studies from subalpine sites have application in forestry management, wildlife conservation, and archaeological reconstruction. For example, on Vancouver Island, the Vancouver Island marmot (Marmota vancouverensis) is near extinction and conservation of the species can benefit from understanding habitat dynamic at high elevations.

  10. Landtype-forest community relationships: A case study on the Mid-Cumberland Plateau.

    PubMed

    Arnold, D H; Smalley, G W; Buckner, E R

    1996-01-01

    Relationships between forest communities and landtypes (the most detailed level of a hierarchical land classification system) were determined for the Prentice Cooper State Forest (PCSF), located on the southern tip of Walden Ridge, west of Chattanooga, Tennessee.Four extensive landtypes within the Mullins Cove area of PCSF were sampled: 1) broad sandstone ridges-south aspect (LT-3), 2) north sandstone slopes (LT-5), 3) south sandstone slopes (LT-6), and 4) plateau escarpment and upper sandstone slopes and benches-south aspect (LT-17). Rectangular, 0.04-hectare plots specified sub-plots for sampling overstory, midstory, sapling/shrub, seedling/herb forest strata, and physical site characteristics. Plots (139) were allocated by landtype using a random start with subsequent systematic location.Multivariate statistical techniques were used to 1) examine the distinctness of forest communities occurring among landtypes (discriminant analysis), 2) describe the forest communities occurring within landtypes (cluster analysis), and 3) determine factors controlling the spatial distribution of forest communities on the landscape (factor analysis).Different relative importance values of species among communities along with different community combinations among landtypes resulted in distinct forest vegetation among landtypes.Chestnut oak (Quercus prinus L.), white oak (Quercus alba L.), and shortleaf pine (Pinus echinata Miller) communities occurred on all four landtypes. Scarlet oak (Quercus coccinia Muenchh.) communities occurred on LT-5, LT-6, and LT-17. Black oak (Quercus velutina Lam.) communities occurred on LT-3 and LT-5. Yellow-poplar (Liriodendron tulipifera L.), northern red oak (Quercus rubra L.), and eastern hemlock (Tsuga canadensis (L.) Carr.), communities occurred only on LT-17.Landscape scale factors that varied along an elevation gradient were dominant in controlling spatial distribution of forest communities. Microsite factors were secondary controllers. Specific ecological factors could not be determined by factor analysis.Relatively distinct vegetation occurs among sampled landtypes on the PCSF. This study provides additional evidence that the land classification system divides the Mid-Cumberland Plateau landscape into distinct ecological units. PMID:24198014

  11. Mid-Pliocene to Early Quaternary Evolution of the Beringian Arctic from Deep Drilling at Lake El'gygytgyn, Chukotka: initial results (Invited)

    NASA Astrophysics Data System (ADS)

    Brigham-Grette, J.; Melles, M.; Minyuk, P.; Andreev, A.; Snyder, J.; Wennrich, V.; Lake El'Gygytgyn Scientific Party

    2010-12-01

    One of the primary objectives for deep drilling at Lake El’gygytgyn (67°30' N, 172°05' E), formed 3.6 Ma ago by a meteorite impact event, was to recover lacustrine sediments that would provide the first high resolution Pliocene-Pleistocene paleoclimate record from the terrestrial Arctic. While discontinuous, spatially diverse Pliocene marine records are known from the arctic borderlands at the outcrop scale, the Lake El’gygytgyn record is critically important for balancing the inherent marine bias we currently have in understanding the climate variability of a world warmer than today. Moreover, this continuous land record contributes to our knowledge of the terminal Pliocene transition, be it steps, jolts or plunges, into the early Quaternary. The Pliocene portion of the lake record recovered extends from 130 m to 315 m depth below lake floor with nearly twice the sedimentation rate of Quaternary interval, presumably due to enhanced hydrologic systematics. The lower most, initial 15 m of the lake sequence directly after the meteorite impact appear to be sterile perhaps due to the intense heat generated by the impact that would have taken thousands of years to dissipate. The remaining portion of the Pliocene sequence is characterized by sequences of lacustrine mud overlain by coarser facies. Palynologically studied portions of the core are mostly dominated by tree pollen, providing us with a compositional idea of changes in Pliocene El’gygtgyn forests of pine (Pinus), larch (Larix) spruce (Picea), fir (Abies), alder (Alnus), and, hemlock (Tsuga), not just scrubs. However, sediments paleomagnetically dated between 3.11 and 3.04 Ma ago show dramatic decrease in tree pollen contents, while pollen of Artemisia and spores of Selaginella rupestris and coprophiluous fungi became common elements in the record. Such changes point to treeless environments that can be described as early tundra-steppe. We present here a very preliminary compilation of the collective proxy results of many investigators and place the results in the context of earlier studies of the Pliocene Arctic.

  12. Phenology of belowground carbon allocation in a mid-latitude forest

    NASA Astrophysics Data System (ADS)

    Abramoff, R. Z.; Klosterman, S.; Finzi, A. C.

    2012-12-01

    Annual forest productivity and carbon storage are affected by the amount and timing of carbon allocated belowground. Despite clear relationships between some climate factors (e.g. temperature) and NPP, there are still large gaps in our understanding of the partitioning between above and belowground C allocation. It is generally assumed that above and belowground phenology is synchronous, but a number of recent studies show that there is wide variability. Some phenological studies suggest that root production peaks are offset from leaf out and shoot elongation. Related belowground processes such as root respiration and nonstructural carbohydrate accumulation may also be offset from root or shoot production as a result of tradeoffs in C allocation. Due to uncertainties in the seasonal pattern and magnitude of allocation to roots, we have collected measurements of root phenology for three temperate tree species at Harvard Forest in Petersham, MA: eastern hemlock (Tsuga canadensis), red oak (Quercus rubra), and white ash (Fraxinus americana). Bi-weekly to monthly measurements of root production, root respiration, and root nonstructural carbohydrate content are used to determine when roots are receiving C from aboveground and patterns of C use. Minirhizotron and soil core data suggest that fine root biomass does not accumulate in a unimodal peak. In T.canadensis stands, fine root production peaks in late May, coinciding with green up and shoot elongation. In Q.rubra stands, fine root production begins in early June, about 3 weeks after leaf out and continues throughout the season in oscillating peaks. Average turnover times for Q.rubra and T.canadensis were 3.76 years and 6.83 years respectively. Standing root biomass for all stands fluctuates seasonally but with high spatial variability, with live fine root biomass averaging 210 ± 75.2 gC m-2 in F.americana stands, 554 ± 241 gC m-2 in Q.rubra, and 449 ± 172 gC m-2 in T.canadensis. Root respiration for all stands increases with temperature from early May to mid-June, with an average seasonal Q10 of 2.1. Nonstructural carbohydrates in F.americana and Q.rubra roots experience a slight drawdown from mid-May to late-June, coinciding with increases in root production and respiration. Nonstructural carbohydrates in all stands accumulate after June. The lack of synchronicity of these processes suggests that trade-offs in C allocation, in addition to abiotic factors such as temperature and soil water content, govern the timing of belowground processes.

  13. Impacts of a changing winter precipitation regime on the Great Snowforest of British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Knudsvig, H.; Dery, S. J.; Coxson, D.

    2012-12-01

    Rising air temperatures have profoundly impacted British Columbia (BC) mountain ecosystems, including its Interior Wetbelt. This region supports the sole Interior Temperate Rainforest (ITR), or perhaps more appropriately "snowforest", of North America. This snowforest encompasses about 30,500 km2 and contains Western redcedar (Thuja plicata) and western hemlock (Tsuga heteropylla) in excess of 1500 years old. This region is projected to be one of the more vulnerable biogeoclimatic zones in BC due to forest operations and climate change. Loss of snow as a storage medium has the potential to negatively affect the forest. A decrease in snow water equivalent (SWE) has the potential to decrease soil moisture values; impacts of decreased water availability in this region have the possibility to affect soil moisture storage, vegetative species composition, flora and fauna interdependence, and pathogen outbreaks. Given the projected climate change in high latitude and altitude areas, this project analyzes the contemporary and potential future climate of BC's Interior Wetbelt and explores the possible environmental and ecohydrological impacts of climate change on the snowforest. Models project an increase in air temperature and precipitation but a decrease in snowfall in this region. Analyses of the snow depth, SWE, and temperature from the Upper Fraser River Basin automated snow pillow sites of the BC River Forecast Centre (RFC) were conducted; snow depth, SWE, and temperature were also measured at the field site via automated weather stations and bi-monthly snow surveys. Surveys recorded depth and SWE after observed peak accumulation and continued until snowpack was depleted in 80% of the field site. To determine the influence of precipitation on the soil moisture levels in the ITR, soil moisture and water table levels were measured for the 2011-12 water year in addition to meteorological conditions; snow, spring water, and near surface ground water samples were collected and analyzed for the environmental isotopes of deuterium and oxygen-18. Analysis of the RFC's snow pillow data shows April 1 snow depth has been highly variable in the last 25 years with an overall decline in depth and SWE values. Soil moisture values at the study site were consistent through the year but showed a peak during spring melt and a decline during August, the driest month of summer in this region. Isotopic analysis on the water samples is on-going. The Upper Fraser River Basin experienced an above-normal to record snowpack the winter of 2011-12, thus observed values may not be indicative of the overall trend for this area. Trends in this interconnected ecosystem can assist in determining impacts of climate change to northern climates.

  14. Vegetation Dynamics in the Kenai Lowlands, Alaska during the Late Pleistocene and Holocene

    NASA Astrophysics Data System (ADS)

    Jones, M. C.; Peteet, D. M.

    2005-12-01

    The use of paleoinformation through ecosystem reconstruction can help us understand the behavior and sensitivity of the boreal forest as climate continues to change. A 2.5-meter sediment core extracted from Swanson Fen, a muskeg in the northern Kenai Lowlands on the Kenai Peninsula, Alaska, provides a sensitive Holocene paleoenvironmental record that lies in an ecotone between interior boreal forest and maritime coastal forest today. The core was sampled at 2-cm intervals and processed for pollen and spores. Five intervals were dated using AMS radiocarbon dating, and the basal macrofossils produced an age of 12,245 ±45 radiocarbon years. The central Kenai Peninsula Lowlands underwent a number of marked vegetational and climatic changes since deglaciation. Four distinct vegetation zones reveal changes starting in the late Pleistocene. The pioneer vegetation includes a dominance of herbaceous ( Artemisia, Apiaceae, Asteroideae)and shrubby ( Betula) species. The second zone (beginning at 9890±45 radiocarbon years) and marking the Holocene boundary, shows a striking increase in Polypodiaceae (ferns) and Picea (spruce) and a decrease in shrubby species such as Betula, indicative of warming. The third zone indicates a decline in Polypodiaceae and a reemergence of Betula species, while the final most recent zone reveals a rapid resurgence in Picea and Tsuga mertensiana (Mountain hemlock) species. While a general warming trend occurred following deglaciation, vegetation patterns suggest extended periods of increased precipitation, for example in the early Holocene, as is evidenced by the plethora of Polypodiaceae. A movement and an intensification of the Aleutian Low could explain these periods of increased precipitation over the Kenai Peninsula. Alternatively, this spike in Polypodiaceae can be explained by increased disturbance. The presence of 10 % Picea pollen at the base of the core suggests that one of the Picea species may have survived the last glaciation in the region. A decrease in Picea pollen and an increase in herbaceous ( Artemisia, Apiaceae, Asteroideae) pollen in the late Quaternary suggest a reversal to cooler conditions before warming resumed at the Holocene boundary, and Picea once again increased. This coincides with the timing of the Younger Dryas in the North Atlantic, and suggests that this phenomenon was felt on the Kenai Peninsula.

  15. Inferring long-term carbon sequestration from tree rings at Harvard Forest: A calibration approach using tree ring widths and geochemistry / flux tower data

    NASA Astrophysics Data System (ADS)

    Belmecheri, S.; Maxwell, S.; Davis, K. J.; Alan, T. H.

    2012-12-01

    Improving the prediction skill of terrestrial carbon cycle models is important for reducing the uncertainties in global carbon cycle and climate projections. Additional evaluation and calibration of carbon models is required, using both observations and long-term proxy-derived data. Centennial-length data could be obtained from tree-rings archives that provide long continuous series of past forest growth changes with accurate annual resolution. Here we present results from a study conducted at Harvard Forest (Petersham, Massachusetts). The study examines the potential relationship between δ13C in dominant trees and GPP and/or NEE measured by the Harvard Forest flux tower (1992-2010). We have analyzed the δ13C composition of late wood-cellulose over the last 18 years from eastern hemlock (Tsuga canadensis) and northern red oak (Quercus rubra) trees growing in the flux tower footprint. δ13C values, corrected for the declining trend of atmospheric δ13C, show a decreasing trend from 1992 to 2010 and therefore a significant increase in discrimination (Δ). The intra-cellular CO2 (Ci) calculated from Δ shows a significant increase for both tree species and follows the same rate of atmospheric CO2 (Ca) increase (Ci/Ca increases). Interestingly, the net Ci and Δ increase observed for both species did not result in an increase of the iWUE. Ci/Ca is strongly related to the growing season Palmer Drought Severity Index (PDSI) for both species thus indicating a significant relationship between soil moisture conditions and stomatal conductance. The Ci trend is interpreted as a result of higher CO2 assimilation in response to increasing soil moisture allowing a longer stomata opening and therefore stimulating tree growth. This interpretation is consistent with the observed increase in GPP and the strengthening of the carbon sink (more negative NEE). Additionally, the decadal trends of basal area increment (BAI) calculated from tree-ring widths exhibit a positive trend over the last two decade. Tree-ring width and δ13C results show the potential of these parameters as proxies for reconstructions of past CO2 assimilation and carbon sequestration by woody biomass beyond the time span covered by calibration data, and extending to the centennial time scales encompassed by tree-ring records.

  16. 78 FR 28628 - Notice of Determinations Regarding Eligibility To Apply for Worker Adjustment Assistance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-15

    ... Corning Corporation, Adecco, Qualified Staffing, SimplexGrennell LP. 82,509A Hemlock Semiconductor LLC, Dow Clarksville, TN..... February 27, 2012. Corning Corporation, Adecco, Qualified Staffing,...

  17. Implications of high amplitude atmospheric CO2 fluctuations on past millennium climate change

    NASA Astrophysics Data System (ADS)

    van Hoof, Thomas; Kouwenberg, Lenny; Wagner-Cremer, Friederike; Visscher, Henk

    2010-05-01

    Stomatal frequency analysis of leaves of land plants preserved in peat and lake deposits can provide a proxy record of pre-industrial atmospheric CO2 concentration complementary to measurements in Antarctic ice cores. Stomatal frequency based CO2 trends from the USA and NW European support the presence of significant CO2 variability during the first half of the last millennium (Kouwenberg et al., 2005; Wagner et al., 2004; van Hoof et al., 2008). The timing of the most significant perturbation in the stomata records (1200 AD) is in agreement with an observed CO2 fluctuation in the D47 Antarctic ice-core record (Barnola et al., 1995; van Hoof et al., 2005). The amplitude of the stomatal frequency based CO2 changes (> 34ppmv) exceeds the maximum amplitude of CO2 variability in the D47 ice core (< 10 ppmv). A modelling experiment taking into account firn-densification based smoothing processes in the D47 ice core proved, however, that the amplitude difference between the stomata record and the D47 ice-core can be explained by natural smoothing processes in the ice (van Hoof et al., 2005). This observation gives credence to the existence of high-amplitude CO2 fluctuations during the last millennium and suggests that high resolution ice core CO2 records should be regarded as a smoothed representation of the atmospheric CO2 signal. In the present study, potential marine and terrestrial sources and sinks associated with the observed atmospheric CO2 perturbation will be discussed. The magnitude of the observed CO2 variability implies that inferred changes in CO2 radiative forcing are of a similar magnitude as variations ascribed to other forcing mechanisms (e.g. solar forcing and volcanism), therefore challenging the IPCC concept of CO2 as an insignificant preindustrial climate forcing factor. References Barnola J.M., M. Anklin, J. Porcheron, D. Raynaud, J. Schwander and B. Stauffer 1995. CO2 evolution during the last millennium as recorded by Antarctic and Greenland ice. Tellus, v 47B, p. 264-272 Kouwenberg L.L.R., F. Wagner, W.M. Kürschner and H. Visscher 2005. Atmospheric CO2 fluctuations during the last Millennium reconstructed by stomatal frequency analysis of Tsuga heterophylla needles. Geology, v. 33, no.1, pp. 33-36 van Hoof T.B., K.A. Kaspers, F. Wagner, R.S.W. van de Wal, W.M. Kürschner and H. Visscher 2005. Atmospheric CO2 during the 13th century AD: reconciliation of data from ice core measurements and stomatal frequency analysis. Tellus B, v. 57, pp. 351-355 van Hoof T.B., F. Wagner-Cremer, W.M. K Kürschner and H. Visscher 2008. A role for atmospheric CO2 in preindustrial climate forcing. Proceedings of the National Academy of Sciences of the USA, v. 105, no. 41, pp. 15815-15818 Wagner F., L.L.R. Kouwenberg, T.B. van Hoof and H. Visscher 2004. Reproducibility of Holocene atmospheric CO2 records based on stomatal frequency. Quartenary Science Reviews. V. 23, pp. 1947-1954

  18. Root phenology at Harvard Forest and beyond

    NASA Astrophysics Data System (ADS)

    Abramoff, R. Z.; Finzi, A.

    2013-12-01

    Roots are hidden from view and heterogeneously distributed making them difficult to study in situ. As a result, the causes and timing of root production are not well understood. Researchers have long assumed that above and belowground phenology is synchronous; for example, most parameterizations of belowground carbon allocation in terrestrial biosphere models are based on allometry and represent a fixed fraction of net C uptake. However, using results from metaanalysis as well as empirical data from oak and hemlock stands at Harvard Forest, we show that synchronous root and shoot growth is the exception rather than the rule. We collected root and shoot phenology measurements from studies across four biomes (boreal, temperate, Mediterranean, and subtropical). General patterns of root phenology varied widely with 1-5 production peaks in a growing season. Surprisingly, in 9 out of the 15 studies, the first root production peak was not the largest peak. In the majority of cases maximum shoot production occurred before root production (Offset>0 in 32 out of 47 plant sample means). The number of days offset between maximum root and shoot growth was negatively correlated with median annual temperature and therefore differs significantly across biomes (ANOVA, F3,43=9.47, p<0.0001). This decline in offset with increasing temperature may reflect greater year-round coupling between air and soil temperature in warm biomes. Growth form (woody or herbaceous) also influenced the relative timing of root and shoot growth. Woody plants had a larger range of days between root and shoot growth peaks as well as a greater number of growth peaks. To explore the range of phenological relationships within woody plants in the temperate biome, we focused on above and belowground phenology in two common northeastern tree species, Quercus rubra and Tsuga canadensis. Greenness index, rate of stem growth, root production and nonstructural carbohydrate content were measured beginning in April 2012 through August 2013 at the Harvard Forest in Petersham, MA, USA. Greenness and stem growth were highest in late May and early June with one clear maximum growth period. In contrast, root growth was characterized by multiple production peaks. Q. rubra root growth experienced many small flushes around day of year (DOY) 156 (early June) and one large peak on 234 (late August). T. canadensis root growth peaked on DOY 188 (early July), 234.5 (late August) and 287 (mid-October). However, particular phenological patterns varied widely from site to site. Despite large spatial heterogeneity, it appears that Q. rubra experiences greater overall root production as well as more allocation to roots during the growing season. The storage pool of nonstructural carbohydrates experiences a mid-summer drawdown in Q. rubra but not T. canadensis roots. Timing of belowground C allocation to root growth and nonstructural carbohydrate accumulation may be regulated by climate factors as well as endogenous factors such as vessel size, growth form, or tradeoffs in C allocated between plant organs. Plant roots supply substrate to microbial communities and hence their production feeds back to other plant and soil processes that affect ecosystem C fluxes.

  19. 68. VIEW OF THE SOUTH LAWN EDGE TOWARD THE WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    68. VIEW OF THE SOUTH LAWN EDGE TOWARD THE WEST SLOPE. VIEW INCLUDES LEUCOTHOE AND CANADIAN HEMLOCK ON THE LEFT. (DUPLICATE OF HABS No. MA-1168-34) - Fairsted, 99 Warren Street, Brookline, Norfolk County, MA

  20. 51. VIEW FROM BENEATH THE ENTRY ARCH LOOKING AT THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. VIEW FROM BENEATH THE ENTRY ARCH LOOKING AT THE CIRCULAR DRIVE. THE HISTORIC CANADIAN HEMLOCK IS IN THE CENTER BED. (DUPICATE OF HABS No. MA-1168-16) - Fairsted, 99 Warren Street, Brookline, Norfolk County, MA

  1. Comparison of ultrastructure, pollen tube growth pattern and starch content in developing and abortive ovaries during the progamic phase in hazel.

    PubMed

    Liu, Jianfeng; Zhang, Huidi; Cheng, Yunqing; Wang, Ju; Zhao, Yixin; Geng, Wanting

    2014-01-01

    HIGHLIGHTSIn an abortive ovary of hazel, an integument seldom differentiated and a mature embryo sac never developed.In an abortive ovary of hazel, pollen tube growth was arrested at the style base about 40 days after blooming. Thus, fertilization of the ovule was precluded.Ovary abortion in the four hybrid cultivars was indicated to be associated with insufficient resource availability to support fruit set by all flowers, whereas ovary abortion in C. heterophylla was at least partly determined by pollen availability. In Northeast China, a high frequency of ovary abortion contributes to serious losses in yield of hazelnut. The development of pistillate inflorescences and fruit clusters of four large-fruited hybrid hazel cultivars and the small-fruited Corylus heterophylla were used to study ovary abortion and its possible causes during the progamic phase in hazel. The average number of pistillate (ANP) flowers per inflorescence and average number of fruit (ANF) per cluster of four hybrid hazel cultivars were 7.6-8.5 and 2.4-3.0 respectively; in C. heterophylla, its ANP and ANF was 5.8-6.2 and 3.5, respectively. The total drop varied from 50 to 67%. Ovary abortion in hazel initiated from about 30 days after blooming. The percentage of abortive ovaries (PAO) in the four hybrid hazel cultivars ranged from 63 to 72%, and was significantly higher than that of C. heterophylla (29-42%). Only the abortive ovary ratio of C. heterophylla was significantly reduced after artificial pollination. Fruit number per cluster was positively and negatively correlated with yield and nut mass, respectively. In abortive ovaries, the diameter remained less than 2 mm during the entire fruit development, an integument seldom differentiated and a mature embryo sac never developed. In addition, pollen tube growth was arrested at the style base about 40 days after blooming. Thus, fertilization of the ovule was precluded. Compared with abortive ovary, starch content in developing ovary of four hybrid hazel cultivars and C. heterophylla were significantly higher. This study suggests that abortive ovary was incapable to finish fertilization process due to the absence of mature embryo sac and arrested pollen tubes, and this is likely associate with insufficient resource availability to support fruit set by all flowers in four hybrid hazel cultivars, whereas ovary abortion in C. heterophylla is at least partly determined by pollen availability. PMID:25339969

  2. Comparison of ultrastructure, pollen tube growth pattern and starch content in developing and abortive ovaries during the progamic phase in hazel

    PubMed Central

    Liu, Jianfeng; Zhang, Huidi; Cheng, Yunqing; Wang, Ju; Zhao, Yixin; Geng, Wanting

    2014-01-01

    HIGHLIGHTS In an abortive ovary of hazel, an integument seldom differentiated and a mature embryo sac never developed.In an abortive ovary of hazel, pollen tube growth was arrested at the style base about 40 days after blooming. Thus, fertilization of the ovule was precluded.Ovary abortion in the four hybrid cultivars was indicated to be associated with insufficient resource availability to support fruit set by all flowers, whereas ovary abortion in C. heterophylla was at least partly determined by pollen availability. In Northeast China, a high frequency of ovary abortion contributes to serious losses in yield of hazelnut. The development of pistillate inflorescences and fruit clusters of four large-fruited hybrid hazel cultivars and the small-fruited Corylus heterophylla were used to study ovary abortion and its possible causes during the progamic phase in hazel. The average number of pistillate (ANP) flowers per inflorescence and average number of fruit (ANF) per cluster of four hybrid hazel cultivars were 7.6–8.5 and 2.4–3.0 respectively; in C. heterophylla, its ANP and ANF was 5.8–6.2 and 3.5, respectively. The total drop varied from 50 to 67%. Ovary abortion in hazel initiated from about 30 days after blooming. The percentage of abortive ovaries (PAO) in the four hybrid hazel cultivars ranged from 63 to 72%, and was significantly higher than that of C. heterophylla (29–42%). Only the abortive ovary ratio of C. heterophylla was significantly reduced after artificial pollination. Fruit number per cluster was positively and negatively correlated with yield and nut mass, respectively. In abortive ovaries, the diameter remained less than 2 mm during the entire fruit development, an integument seldom differentiated and a mature embryo sac never developed. In addition, pollen tube growth was arrested at the style base about 40 days after blooming. Thus, fertilization of the ovule was precluded. Compared with abortive ovary, starch content in developing ovary of four hybrid hazel cultivars and C. heterophylla were significantly higher. This study suggests that abortive ovary was incapable to finish fertilization process due to the absence of mature embryo sac and arrested pollen tubes, and this is likely associate with insufficient resource availability to support fruit set by all flowers in four hybrid hazel cultivars, whereas ovary abortion in C. heterophylla is at least partly determined by pollen availability. PMID:25339969

  3. McArthur River Field - a Cook Inlet giant

    SciTech Connect

    Stickney, R.B.; Warthen, R.C.

    1985-04-01

    The eighth major discovery in Cook Inlet basin was announced on October 24, 1965, as a result of drilling the Union-operated Grayling 1-A well near the crest of a broad, low-relief anticline that had been mapped from seismic data as early as 1959. The prolific Hemlock Conglomerate was tested at rates exceeding 2000 BOPD. As delineation wells confirmed the size of the accumulation, three separate platforms were ordered and were in place by July 1967, and within three months, production from the Hemlock had begun. Additional oil-productive sands in the Tyonek Formation, immediately overlying the Hemlock as well as several more in the underlying West Foreland, Formation, were placed on production in September 1969. Significant reserves in shallower Tyonek Formation sandstone have only been used so far for platform power and gas lift. Development plans are currently being formulated for these reservoirs in response to the recent increasing demands for gas in Cook Inlet.

  4. Identification of RAPD markers, in situ DNA content and structural chromosomal diversity in some legumes of the mangrove flora of Orissa.

    PubMed

    Jena, S; Sahoo, P; Mohanty, S; Das, A B

    2004-11-01

    Randomly amplified polymorphic DNA (RAPD) markers, karyotypes and 4C DNA content were analyzed in five legume mangroves belonging to the sub-family Papilinoideae (Dalbergia spinosa, Derris heterophylla and D. indica) and Caesalpinioideae (Caesalpinia crista, Cynometra ramiflora) of the family Fabaceae to establish the genetic variability and phylogenetic affinities. Somatic chromosome numbers were reported for the first time in D. spinosa (2n = 20), C. ramiflora (2n = 26) and D. heterophylla (2n = 24) with reconfirmation of the somatic chromosome number in D. indica (2n = 22) and C. crista (2n = 24). Significant intergeneric and interspecific variation of 4C DNA content was observed and that varied from 8.970 pg in C. ramiflora to 28.730 pg in D. indica. From the RAPD analysis, the dendogram showed clustering of Caesalpinia crista and Cynomitra ramiflora into one group (81.80). In the second groups Derris indica and Derris heterophylla were more similar (83.10) than Dalbergia spinosa (85.80). Species-specific DNA markers (900 bp) obtained in D. spinosa from OPN15; 700 and 2000 bp in C. ramiflora from OPN4 and 400 and 800 bp in D. heterophylla and 500 bp DNA fragment in C. crista obtained from OPN-11 were found characteristic RAPD markers of these species. C. crista found more closer affinity to C. ramiflora of the sub-family Caesalpinioideae [genetic distance (1-F) = 0.847]. Derris indica showed closer genetic relation with D. heterophylla [genetic distance (1-F) = 0.856] than D. spinosa [genetic distance (1-F) = 0.876] where Derris and Dalbergia belongs to the sub-family Papilionoideae. By employing these markers the present study has helped to resolve the relationship between the taxonomically diverse leguminous mangroves and study their ability to coexist with mangroves that would shed light on the evolution of mangroves from terrestrial species. PMID:15609544

  5. Role of acid and aluminum-rich media in the growth and nutrition of Pacific Northwest conifers

    SciTech Connect

    Ryan, P.J.

    1983-01-01

    Forest soils of coastal Washington and Oregon tend to be very acidic with large accumulations of organic matter. Yet the productivity of forest species on these sites can attain record levels. The effect of acid and aluminum-rich media on the growth and nutrition of Pacific Northwest conifer species was investigated for western hemlock, Douglas-fir, western redcedar, and Sitka spruce. The four different types of growth media utilized were solution cultures, sand cultures, mineral soils, and forest floor organic matter. Hydroponic nutrient solutions and sand cultures were used in experiments designed to differentiate the effect of aluminum ions from the hydrogen ions generated by hydrolysis of Al/sup 3 +/. Relative to agronomic plants, all the conifers were found tolerant of the acid solutions and high levels of aluminum. Species differed in their relative tolerance to H/sup +/ and Al/sup 3/ ions. Western hemlock seedling growth was superior to Douglas-fir in the acidified soils and forest floor media, while Ca(OH)/sub 2/ amendment favored Douglas-fir. The marginal increase in western hemlock growth in N + P treated soils was highest in acidified soils. Western hemlock exhibited an ability to absorb nutrients in the presence of excess solution H/sup +/ ions, maintain growth with low tissue requirements of Ca and Mg, and accumulate high levels of aluminum in its roots and foliage without major adverse effect. These attributes are considered to make western hemlock the most acid and Al-tolerant of the four Pacific Northwest forest species studied. Western redcedar was second in acid tolerance to western hemlock. This species' ability to accumulate Ca minimized Al absorption and H/sup +/ damage to its roots.

  6. A field test of the effect of acidic rain on ion balance in a woodland salamander

    SciTech Connect

    Frisbie, M.P.; Wyman, R.L. )

    1994-06-01

    Earlier laboratory studies demonstrated that red-backed salamanders, Plethodon cinereus, are susceptible to osmotic disruption by low pH substrates. In natural systems, however, acidic input from precipitation may be mediated by soils before it impacts salamanders. We tested the effect of acidic rain on sodium balance in salamanders by confining individuals in enclosure in two forest types (hemlock, beech) for 34 d. Enclosures received artificial rain of either pH 3 or 5 every 3-4 d. Soils inside enclosures in the hemlock forest were more acidic than those in the beech forest at the outset. At termination, [H[sup +

  7. Antioxidant properties of several medicinal mushrooms.

    PubMed

    Mau, Jeng-Leun; Lin, Hsiu-Ching; Chen, Chin-Chu

    2002-10-01

    Three species of medicinal mushrooms are commercially available in Taiwan, namely, Ganoderma lucidum (Ling-chih), Ganoderma tsugae (Sung-shan-ling-chih), and Coriolus versicolor (Yun-chih). Methanolic extracts were prepared from these medicinal mushrooms and their antioxidant properties studied. At 0.6 mg/mL, G. lucidum, G. lucidum antler, and G. tsugae showed an excellent antioxidant activity (2.30-6.41% of lipid peroxidation), whereas C. versicolor showed only 58.56%. At 4 mg/mL, reducing powers were in the order G. tsugae (2.38) approximately G. lucidum antler (2.28) > G. lucidum (1.62) > C. versicolor (0.79). At 0.64 mg/mL, scavenging effects on the 1,1-diphenyl-2-picrylhydrazyl radical were 67.6-74.4% for Ganoderma and 24.6% for C. versicolor. The scavenging effect of methanolic extracts from G. lucidum and G. lucidum antler on hydroxyl radical was the highest (51.2 and 52.6%) at 16 mg/mL, respectively. At 2.4 mg/mL, chelating effects on ferrous ion were in the order G. lucidum antler (67.7%) > G. lucidum (55.5%) > G. tsugae (44.8%) > C. versicolor (13.2%). Total phenols were the major naturally occurring antioxidant components found in methanolic extracts from medicinal mushrooms. Overall, G. lucidum and G. tsugae were higher in antioxidant activity, reducing power, scavenging and chelating abilities, and total phenol content. PMID:12358482

  8. Process feasibility study in support of silicon material Task I. Quarterly technical progress report (XIX), March 1-May 31, 1980

    SciTech Connect

    Yaws, C.L.; Li, K.Y.

    1980-06-01

    Analyses of process system properties were continued for chemical materials important in the production of silicon. Major physical, thermodynamic and transport property data are reported for silicon including critical constants, vapor pressure, heat of vaporization, heat of sublimation, heat capacity, density, surface tension, viscosity and thermal conductivity. The property data covers both liquid and solid phases and are reported as a function of temperature for rapid engineering usage. Major efforts in chemical engineering analysis centered on the HSC process (Hemlock Semiconductor Corporation). The approach for the process involves performing initial analysis for DCS production (dichlorosilane) and then perorming analysis of polysilicon production from the DCS. For the DCS production, status and progress are reported for primary activities of base case conditions (65%), reaction chemistry (65%), process flowsheet (60%), material balance (50%) and energy balance (40%). Two key features - redistribution reactor relocation and final distillation - are introduced to increase yield of DCS by about 10 to 20%, help insure purity and reduce potential dust (fine particle nucleation) components in the polysilicon feed material. The preliminary flowsheet for DCS production was forwarded to Hemlock Semiconductor Corporation for initial screening and review. Hemlock Semiconductor is in agreement in regards to relocation of the redistribution reactor to increase yield. Additional follow-up review is in progress including boron removal options identified by Hemlock Semiconductor. 166 references.

  9. 25 CFR 241.2 - Annette Islands Reserve; definition; exclusive fishery; licenses.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... as a reservation by section 15 of the Act of March 3, 1891 (26 Stat. 1101, 48 U.S.C. sec. 358), and..., Walker Island, Lewis Island, Spire Island, Hemlock Island, and adjacent rocks and islets, located within....C. sec. 1165). (c) Licenses. Members of the Metlakatla Indian Community, and such other...

  10. 25 CFR 241.2 - Annette Islands Reserve; definition; exclusive fishery; licenses.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... as a reservation by section 15 of the Act of March 3, 1891 (26 Stat. 1101, 48 U.S.C. sec. 358), and..., Walker Island, Lewis Island, Spire Island, Hemlock Island, and adjacent rocks and islets, located within....C. sec. 1165). (c) Licenses. Members of the Metlakatla Indian Community, and such other...

  11. 25 CFR 241.2 - Annette Islands Reserve; definition; exclusive fishery; licenses.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... as a reservation by section 15 of the Act of March 3, 1891 (26 Stat. 1101, 48 U.S.C. sec. 358), and..., Walker Island, Lewis Island, Spire Island, Hemlock Island, and adjacent rocks and islets, located within....C. sec. 1165). (c) Licenses. Members of the Metlakatla Indian Community, and such other...

  12. Changes in Landscape Greenness: Anthropogenic or Natural: Proof of Concept, Selected Study Areas

    EPA Science Inventory

    We selected four National Forest areas that span east to west of USA to conduct the study over the 25-year period from 1989 through 2013: GWJ (Virginia), Chatt-O (Georgia), Kisatchie (Louisiana), Hemlock Restoration (California). The Normalized Difference Vegetation Index (NDV...

  13. Stereoselective potencies and relative toxicities of y-Coniceine and N-Methylconiine enantiomers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    '-Coniceine, coniine, and N-methylconiine are toxic alkaloids present in poison hemlock (Conium maculatum). We previously reported the comparison of the relative potencies of (+)- and (-)-coniine enantiomers. In this study, we synthesized '-coniceine and the enantiomers of N-methylconiine and dete...

  14. PHOTOGRAPHIC COPY REDUCTION OF CAD DRAWING (FROM COLLECTION OF GIFFORD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PHOTOGRAPHIC COPY REDUCTION OF CAD DRAWING (FROM COLLECTION OF GIFFORD PINCHOT NATIONAL FOREST). HEMLOCK DAM (TROUT CREEK) SITE PLAN. 1995 FISH LADDER “ATTRACTION FLOW” MODIFICATIONS - Trout Creek Dam, River Mile 1.8 on Trout Creek, Carson, Skamania County, WA

  15. Comparative analysis of carbon, water, and energy exchanges in co-located mid-latitude forests at various stages of development

    NASA Astrophysics Data System (ADS)

    Williams, C. A.; Munger, J. W.; Hadley, J.; Fitzjarrald, D. R.

    2010-12-01

    Biosphere-atmosphere exchanges of mass and energy vary with forest type, stand age, and following disturbance, but the degree, character, and persistence of these variations remain poorly understood. This work explores such gradients by synthesizing across a local network of flux tower sites within Harvard Forest (central Massachusetts). We examine how CO2, H2O, and energy exchanges compare among mature and intermediate aged deciduous forests, a mature hemlock forest, and a newly instrumented site in the early stages of secondary succession following a recent clearcut. We find markedly lower growing season evapotranspiration in the hemlock stand compared to adjacent deciduous forests, lower still in the revegetating clearcut. Daytime net ecosystem carbon exchange follows a similar pattern, with highest uptake in the deciduous forests, intermediate in the hemlock site, and lowest in the clearcut. This is true despite sizeable midday uptake in the clearcut during the second growing season post-harvest. Large nighttime CO2 emissions from the clearcut indicate high respiration rates of the early succession vegetation as well as vigorous decomposition of the abundant woody debris and litter left onsite after harvest. Surface albedo and corresponding net radiation are both surprisingly consistent across these adjacent cover types. Implications for water resources and carbon balance of New England landscapes will be discussed, particularly within the contexts of human and natural disturbances, such as harvesting and Hemlock Wooly Adelgid infestations.

  16. Crooked Calf Syndrome: Managing Lupines on Rangelands of the Channel Scablands of East-Central Washington State

    Technology Transfer Automated Retrieval System (TEKTRAN)

    “Crooked calf syndrome”, the contracture-type skeletal defects and cleft palate caused by velvet lupine (Lupinus leucophyllus) on the channel Scablands of east-central Washington State are the same as those defects induced by Conium maculatum (poison-hemlock) and Nicotiana spp. (wild tobacco) in rum...

  17. Voluntary Euthanasia and the Right to Die: A Dialogue with Derek Humphry.

    ERIC Educational Resources Information Center

    Sinnett, E. Robert; And Others

    1989-01-01

    Presents interview with Derek Humphry, founder of the Hemlock Society (an international right-to-die organization), who shares his personal experiences, as well as his efforts to educate the public and stimulate legal reform. Notes Humphry has dedicated more than a decade to this highly charged universal problem. (Author/ABL)

  18. Haida Food Gathering and Preparation.

    ERIC Educational Resources Information Center

    Cogo, Robert

    Students are introduced to the Haida language as well as to traditional Haida foods in this booklet, one in a series of curriculum materials on Southeast Alaska Natives. Ten selections written in simple language describe a Haida barbecue, Indian bread, sea cucumbers, black sea weed, the edible pulp sap of Hemlock, Indian ice cream made from soap

  19. 50 CFR 32.68 - West Virginia.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... of any tree or other refuge feature with flagging, paint, or other substance. 6. We prohibit the cutting and trimming of coniferous trees (balsam fir, red spruce, and hemlock). We prohibit construction of blinds from these materials. 7. We prohibit permanent tree stands, but we allow use of...

  20. 50 CFR 32.68 - West Virginia.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... buckshot. 5. We prohibit the marking of any tree or other refuge feature with flagging, paint, or other substance. 6. We prohibit the cutting and trimming of coniferous trees (balsam fir, red spruce, and hemlock). We prohibit construction of blinds from these materials. 7. We prohibit permanent tree stands, but...

  1. 50 CFR 32.68 - West Virginia.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... of any tree or other refuge feature with flagging, paint, or other substance. 6. We prohibit the cutting and trimming of coniferous trees (balsam fir, red spruce, and hemlock). We prohibit construction of blinds from these materials. 7. We prohibit permanent tree stands, but we allow use of...

  2. 50 CFR 32.68 - West Virginia.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... of any tree or other refuge feature with flagging, paint, or other substance. 6. We prohibit the cutting and trimming of coniferous trees (balsam fir, red spruce, and hemlock). We prohibit construction of blinds from these materials. 7. We prohibit permanent tree stands, but we allow use of...

  3. Haida Food Gathering and Preparation.

    ERIC Educational Resources Information Center

    Cogo, Robert

    Students are introduced to the Haida language as well as to traditional Haida foods in this booklet, one in a series of curriculum materials on Southeast Alaska Natives. Ten selections written in simple language describe a Haida barbecue, Indian bread, sea cucumbers, black sea weed, the edible pulp sap of Hemlock, Indian ice cream made from soap…

  4. Fetal-muscle type nicotinic acetylcholine receptor activation in TE-671 cells, and inhibition of fetal movement in a day 40 pregnant goat model by optical isomers of the piperidine alkaloid coniine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Coniine is an optically active toxic piperidine alkaloid and nicotinic acetylcholine receptor (nAChR) agonist found in poison hemlock (Conium maculatum L.). Coniine teratogenicity is hypothesized to be due to the binding, activation, and prolonged desensitization of fetal muscle-type nAChR which re...

  5. Gods behaving badly.

    PubMed

    Retsas, Spyros

    2015-02-01

    This paper addresses the myths surrounding the birth and death of Asclepios, the popular healing God of the Greeks and his place among other deities of the Greek Pantheon. The enigmatic invocation of Asclepios by Socrates, the Athenian philosopher condemned to take the hemlock, in his final moments is also discussed. PMID:24585610

  6. Otherness through Elves: Into Elfland and Beyond

    ERIC Educational Resources Information Center

    Yamazaki, Akiko

    2008-01-01

    This article examines three novels which use stories of elves--especially the ballad "Tam Lin"--as pre-texts, and contemplates how they explore the issue of Otherness. The three novels are "The Sterkarm Handshake" by Susan Price, "Cold Tom" by Sally Prue, and "Fire and Hemlock" by Diana Wynne Jones. Although the novels seem to be about elves as…

  7. Map of vegetation during the last glacial maximum in Japan

    NASA Astrophysics Data System (ADS)

    Tsukada, Matsuo

    1985-05-01

    A vegetation map reconstructed for the Japanese Archipelago (based upon pollen data from 28 sites and plant macrofossil data from 33 sites) at the time of last glacial maximum shows that coniferous forests covered extensive areas of the land. Boreal conifer forests (dominated by the Picea jezoensis complex, P. glehnii, Abies sachalinensis, A. mariesii, Tsuga diversifolia, and Pinus with Larix gmelinii, though the latter species was confined only to the northern part of northeastern Honshu and Hokkaido) occupied the modern cool-temperature deciduous broadleaf and mid-temperate conifer forest zones, and temperate coniferous forests (mainly Picea maximowiczii, P. polita, P. bicolor, P. koyamai, Abies firma, A. homolepis, Tsuga sieboldii, and Pinus), the present warm-temperate evergreen (laurilignosa) forest zone. Small populations of various broadleaf forest species were scattered in the full-glacial temperate conifer forest mainly along the coastal belt, and the true laurilignosa forest was limited in distribution, occurring only in the paleo-Yaku Peninsula.

  8. Climate changes inferred from integrated multi-site pollen data in northern Taiwan

    NASA Astrophysics Data System (ADS)

    Wang, Liang-Chi; Wu, Jiunn-Tzong; Lee, Teh-Quei; Lee, Pei-Fen; Chen, Su-Hwa

    2011-04-01

    In this study, we synthesized the fossil pollen data from 10 lake sediments and 2 land cores to integrate the alteration of forest covered areas in northern Taiwan with changes in humidity and temperature over the last 2000 years. The abundance of arboreal pollen, fern spores and Tsuga pollen in the pollen and spore assemblages were used as indicators. Our results suggested that the climate in northern Taiwan was stably cool and dry during 2000-1000 cal. yr BP, but changed to wet and warm during 1000-500 cal. yr BP, which corresponded to the Medieval Warm Period (MWP). In addition, an increased density and dispersal of Tsuga pollen corresponding to 500-200 cal. yr BP was observed, which corresponded to the Little Ice Age (LIA). In recent years, a decline in Tsuga pollen density and increased fern spore density has been observed, which indicates an increase in temperature associated with elevated rainfall. Based on the synthesized data set, we conducted GIS mapping of such changes in the north of Taiwan over time. The results revealed that the temporal and spatial climate changes could be inferred from the palynological GIS mapping method, and that the fluctuations in temperature over time matched well with the global climate events, including MWP, LIA and recent warming.

  9. Diagenesis of conifer needles in a coastal marine environment

    NASA Astrophysics Data System (ADS)

    Hedges, John I.; Weliky, K.

    1989-10-01

    Physically intact fir, hemlock and cedar needles were isolated from different horizons of a sediment core from a coastal marine bay (Dabob Bay, Washington State, U.S.A.) and from nearby trees and forest litter. Green fir, hemlock and cedar needles were all characterized by glucose-rich aldose mixtures (~30% of tissue carbon), the production of vanillyl and cinnamyl CuO-derived phenols (~8% of tissue carbon) and the presence of both pinitol and myo-inositol (1-2% of tissue carbon). Needles from forest litter were enriched in lignin phenols and non-glucose aldoses and depleted in glucose and cyclitols. The sediment core contained an average of 10 mg/1 of physically intact fir, hemlock and cedar needles, which occurred in similar relative abundances and accounted for less than 1% of the total nonwoody gymnosperm tissue. Compared to the green and litter counterparts, all sedimentary needles were greatly depleted in cyclitols, glucose and p-coumaric acid and enriched in vanillyl phenol precursors. The degree of elevation of vanillyl phenol yield from the degraded needles was used to estimate minimal carbon losses from the samples, which ranged from near 40% for needle litter to almost 70% for the deepest (~100 years old) sedimentary fir/hemlock samples. Although downcore increases in carbon loss and refractory organic components indicated in situ diagenesis, the bulk of overall degradation occurred either on land or during the first 10-20 years after deposition. Atomic C/N ratios of degraded needles were lower than for green counterparts, but nitrogen was lost overall. These relative changes indicate the following stability series: vanillyl phenols > N > ferulic acid, p-hydroxy phenols, most aldoses and bulk tissue > glucose and p-coumaric acid > cyclitols (near 100% loss). Vanillic acid to vanillin ratios, (Ad/Al)v, of the green fir and hemlock needles were unusually high (0.36-0.38) and decreased downcore. Diagenesis also decreased the cinnamyl/vanillyl phenol ratio (C/V) of the deepest sedimentary fir/hemlock needles to 20% of the original value and almost tripled the carbon-normalized yield of total vanillyl plus cinnamyl phenols (Λ). The net result of these compositional variations was to make the lignin component of the buried conifer needles resemble lignin in gymnosperm wood, thereby leading to underestimates of needle input and mass.

  10. A Long Term View of Forest Response to Environmental Change: 25 Years of Studying Harvard Forest

    NASA Astrophysics Data System (ADS)

    Munger, J. W.; Wofsy, S. C.; Lindaas, J.; David, F.; David, O.

    2014-12-01

    Forests influence the budgets of greenhouse gases, and understanding how they will respond to environmental change is critical to accurately predicting future GHG trends. The time scale for climate change is long and forest growth is slow, thus very long measurement periods are required to observe meaningful forest response. We established an eddy flux tower within a mixed forest stand dominated by red oak and red maple at the Harvard Forest LTER site in 1989 where CO2, H2O and energy fluxes together with meteorological observations have been measured continuously. An array of plots for biometric measurements was established in 1993. Flux measurement at an adjacent hemlock stand began in 2000. Records of land use and disturbance and vegetation plot data extend back to 1907. The combined suite of measurements merges observations of instantaneous ecosystem responses to environmental forcing with details of vegetation dynamics and forest growth that represent the emergent properties relevant to long-term ecosystem change. Both the deciduous stand and hemlock stand are accumulating biomass. Each has added over 20 Mg-C ha-1 as woody biomass in trees >10cm dbh since 1990, even though the hemlock stand is older. Net carbon exchange shows enhanced uptake in early spring and late fall months in response to warmer temperatures and likely an increase in evergreen foliage at the deciduous site. Net carbon uptake efficiency at the deciduous stand has increased over time as well as indicated by peak NEE under optimum light conditions. The trend is only partly explained by variation in mean leaf area index and cannot be directly attributed to climate response. The combination of longer growing season and increased uptake efficiency yields a general trend of increasing annual NEE (Fig. 1). However, significant excursions in the trend highlight the sensitivity of forest carbon stocks. The pulse of high annual carbon uptake (peak 6 Mg-C ha-1y-1 in 2008) from 2000-2008 is only partially matched by carbon stored in woody biomass, leaving a large fraction of carbon to have accumulated in litter and fine roots in the forest floor, which has as much carbon as the above-ground woody biomass, but shorter turnover time. Invasion by Hemlock wooly adelgid, an insect that kills hemlock trees portends a major shift in NEE for the hemlock stand in the next decade.

  11. Two Finger Lakes (New York) Through the Twentieth Century: Response of the Diatom Assemblages to Anthropogenic Influences

    NASA Astrophysics Data System (ADS)

    Arnold, M. R.; Chaisson, W. P.

    2002-05-01

    Diatoms in sediment cores from two New York Finger Lakes, Conesus Lake and Hemlock Lake, were enumerated. These lakes are only 8 km apart, but Conesus Lake has a shallower, broader basin and a different diatom complement than Hemlock Lake. Cottages almost completely surrounded Conesus Lake by the 1920s, when the oldest core sediment was deposited. All sampled levels of the core yielded a eutrophic Lake Trophic Status Index (LTSI: 8.3 to 11.6). Eutrophic indicators Aulacosiera granulata, and Stephanodiscus niagarae, and mesoeutrophic A. italica are the dominant diatoms in most samples, consistent with reported nutrient enrichment. Sediment from the 1940s has the lowest LTSI (8.3) during a known wet period. The LTSI is also lower in recent sediments (8.5), likely from sewer system installation in the early 1970s, measures to control agricultural runoff, and increased precipitation. Conesus Lake had low turbidity through most of the 1900s, even with high enrichment. The resident macrophytes, walleye and large zooplankton controlled excess algae growth. During the 1970s, walleye declined, and alewife were introduced, resulting in the loss of large zooplankton and increased turbidity. Even with increased turbidity, the most recent sediment has a lower LTSI; eutrophic A. granulata decrease and mesoeutrophic A. italica increase. Diatoms in the Hemlock Lake core sediments reveal a less anthropogenically impacted lake than Conesus Lake. The bottom portion of the Hemlock Lake core ( ~1870) has 58% of oligomesotrophic A. subarctica, associated with a low LTSI (-0.6). By the latter part of the 1800s, the land around the lake was largely owned by the City of Rochester. Existing cottages were demolished, the land was reforested and the lake used as a reservoir. Alternating increases in mesoeutrophic tychoplanktonic A. italica and mesoeutrophic euplanktonic Tabellaria fenestrata, are consistent with increased nutrient concentration and changing water levels, mostly during historical drought periods. Cyclotella comensis (65%), linked to low total phosphorus enrichment and higher water conditions, increase during the most recent twenty years. The lake is now surrounded by forests and considered pristine. The predominant Conesus Lake core diatoms require higher nutrient enrichment than those in the Hemlock Lake core and indicate a continually disturbed watershed. The Hemlock Lake diatoms are very different and indicate less enrichment. While the LTSIs of both lakes change in response to climatic changes, Conesus Lake consistently shows a higher LTSI. Further studies of longer cores from these lakes are planned.

  12. Radar modeling of a boreal forest

    NASA Technical Reports Server (NTRS)

    Chauhan, Narinder S.; Lang, Roger H.; Ranson, K. J.

    1991-01-01

    Microwave modeling, ground truth, and SAR data are used to investigate the characteristics of forest stands. A mixed coniferous forest stand has been modeled at P, L, and C bands. Extensive measurements of ground truth and canopy geometry parameters were performed in a 200-m-square hemlock-dominated forest plot. About 10 percent of the trees were sampled to determine a distribution of diameter at breast height (DBH). Hemlock trees in the forest are modeled by characterizing tree trunks, branches, and needles as randomly oriented lossy dielectric cylinders whose area and orientation distributions are prescribed. The distorted Born approximation is used to compute the backscatter at P, L, and C bands. The theoretical results are found to be lower than the calibrated ground-truth data. The experiment and model results agree quite closely, however, when the ratios of VV to HH and HV to HH are compared.

  13. Biogenic and thermogenic origins of natural gas in Cook Inlet basin, Alaska

    SciTech Connect

    Claypool, G.E.; Threlkeld, C.N.; Magoon, L.B.

    1980-08-01

    Two types of natural gas occurrences are present in the Cook Inlet basin. The major reserves (1.8 x 10/sup 11/m/sup 3/) occur in shallow (less than 2300 m), nonassociated dry gas fields that contain methane with ..delta.. /sup 13/C in the range of -63 t -56 per mil. These gas fields are in sandstones interbedded with coals of the Sterling and Beluga Formations; the gas fields are interpreted as biogenic in origin. Lesser reserves (1.1 x 10/sup 10/ m/sup 3/) of natural gas are associated with oil in the deeper Hemlock Conglomerate at the base of the Tertiary section; associated gas contains methane with ..delta.. /sup 13/C of about -46 per mil. The gases associated with oil in the Hemlock Conglomerate are thermogenic in origin.

  14. Woody fuel dimensions within Great Smoky Mountains National Park. Research/resources management report

    SciTech Connect

    Harmon, M.E.; Hennessy, T.; Silsbee, D.G.

    1980-01-01

    Diameters and bulk density were examined for downed wood in major forest types found in Great Smoky Mountains National Park. One-hour fuel (0 - 7 mm) diameters were smallest in spruce-fir and hemlock forests, intermediate in yellow pine forests, and largest in hardwood forests. Diameters for 10 hour (7 - 25 mm) and 100 hour (25 - 76 mm) fuels were not significantly different between forest types. Bulk density decreased with a decrease in bark coverage.

  15. Associations between regional moisture gradient, tree species dominance, and downed wood abundance

    NASA Astrophysics Data System (ADS)

    Johnson, A. C.; Mills, J.

    2007-12-01

    Downed wood functions as a source of nurse logs, physical structure in streams, food, and carbon. Because downed wood is important in upland and aquatic habitats, an understanding of wood recruitment along a continuum from wet to dry landscapes is critical for both preservation of biodiversity and restoration of natural ecosystem structure and function. We assessed downed wood in public and private forests of Washington and Oregon by using a subset of the Forest Inventory and Analysis (FIA) database including 15,842 sampled conditions. Multivariate regression trees, ANOVA, and t-tests were used to discern environmental conditions most closely associated with abundance of woody debris. Of the 16 parameters included in the analysis, rainfall, forest ownership, number of damaged standing trees, and forest elevation were most indicative of woody debris abundance. The Hemlock/spruce Group, including hemlock, spruce, cedar, and white pine, most associated with wetter soils, had significantly more downed wood than 12 other forest groups. The Ponderosa Pine Group, indicative of drier sites with higher fire frequencies, included ponderosa pine, sugar pine, and incense cedar, and had significantly less downed wood volume. Overall, the amount of woody debris in either the Spruce/hemlock Group or the Ponderosa Pine Group did not change significantly as tree age increased from 5 to 350 years. Plots within the Hemlock/spruce with greater standing tree volume also had significantly greater downed wood volume. In contrast, greater downed wood volume was not associated with greater standing tree volume in the Ponderosa Pine Group. Knowledge of linkages among environmental variables and stand characteristics are useful in development of regional forest models aimed at understanding the effects of climate change and disturbance on forest succession.

  16. Growth, condition factor, and bioenergetics modeling link warmer stream temperatures below a small dam to reduced performance of juvenile steelhead

    USGS Publications Warehouse

    Sauter, S.T.; Connolly, P.J.

    2010-01-01

    We investigated the growth and feeding performance of juvenile steelhead Oncorhynchus mykiss using field measures and bioenergetics modeling. Juvenile steelhead populations were sampled from mid-June through August 2004 at study sites upstream and downstream of Hemlock Dam. The growth and diet of juvenile steelhead were determined for a warm (summer) and subsequent (late summer) transitional period at each study site. Empirical data on the growth and diet of juvenile steelhead and mean daily temperatures were used in a bioenergetics model to estimate the proportion of maximum consumption achieved by juvenile steelhead by site and period. Modeled estimates of feeding performance were better for juvenile steelhead at the upstream compared to the downstream site during both periods. The median condition factor of juvenile steelhead did not change over the summer at the upstream site, but showed a significant decline over time at the downstream site. A negative trend in median condition factor at the downstream site supported bioenergetics modeling results that suggested the warmer stream temperatures had a negative impact on juvenile steelhead. Bioenergetics modeling predicted a lower feeding performance for juvenile steelhead rearing downstream compared to upstream of Hemlock Dam although food availability appeared to be limited at both study sites during the warm period. Warmer water temperatures, greater diel variation, and change in diel pattern likely led to the reduced feeding performance and reduced growth, which could have affected the overall survival of juvenile steelhead downstream of Hemlock Dam. ?? 2010 by the Northwest Scientific Association.

  17. Diurnal variation in soil respiration under different land uses on Taihang Mountain, North China

    NASA Astrophysics Data System (ADS)

    Liu, Xiuping; Zhang, Wanjun; Zhang, Bin; Yang, Qihong; Chang, Jianguo; Hou, Ke

    2016-01-01

    The aim of this paper is to evaluate the diurnal variation in soil respiration under different land use types on Taihang Mountain, North China, and to understand its response to environmental factors (e.g., soil temperature and moisture) and forest management. Diurnal variations in soil respiration from plantations (Robinia pseudoacacia, Punica granatum, and Ziziphus jujuba), naturally regenerated forests (Vitex negundo var. heterophylla), grasslands (Bothriochloa ischaemum), and farmlands (winter wheat/summer maize) were measured using an LI-8100 automated soil CO2 flux system from May 2012 to April 2013. The results indicated that land use type had a significant effect on the diurnal variation of soil respiration. The diurnal soil respiration from farmlands was highest, followed by Ziziphus jujube, R. pseudoacacia, P. granatum, the lower soil CO2 efflux was found from B. ischaemum and V. negundo var. heterophylla. The diurnal soil respiration across different land use types was significantly affected by soil temperature and moisture, and their interaction. Precipitation-stimulated soil respiration increased more in soil with low water content and less in soil with high water content. The lower diurnal soil respiration from naturally regenerated forests suggests that naturally regenerated vegetation is the optimal vegetation type for reducing global warming.

  18. The influence of microhabitat on the population dynamics of four herbaceous species in a semiarid area of northeastern Brazil.

    PubMed

    Silva, K A; Santos, J M F F; Andrade, J R; Lima, E N; Albuquerque, U P; Ferraz, E M N; Araújo, E L

    2016-02-01

    Variation in annual rainfall is considered the most important factor influencing population dynamics in dry environments. However, different factors may control population dynamics in different microhabitats. This study recognizes that microhabitat variation may attenuate the influence of climatic seasonality on the population dynamics of herbaceous species in dry forest (Caatinga) areas of Brazil. We evaluated the influence of three microhabitats (flat, rocky and riparian) on the population dynamics of four herbaceous species (Delilia biflora, Commelina obliqua, Phaseolus peduncularis and Euphorbia heterophylla) in a Caatinga (dry forest) fragment at the Experimental Station of the Agronomic Research Institute of Pernambuco in Brazil, over a period of three years. D. biflora, C. obliqua and P. peduncularis were found in all microhabitats, but they were present at low densities in the riparian microhabitat. There was no record of E. heterophylla in the riparian microhabitat. Population size, mortality rates and natality rates varied over time in each microhabitat. This study indicates that different establishment conditions influenced the population size and occurrence of the four species, and it confirms that microhabitat can attenuate the effect of drought stress on mortality during the dry season, but the strength of this attenuator role may vary with time and species. PMID:26909622

  19. Community Structure and Survival of Tertiary Relict Thuja sutchuenensis (Cupressaceae) in the Subtropical Daba Mountains, Southwestern China

    PubMed Central

    Tang, Cindy Q.; Yang, Yongchuan; Ohsawa, Masahiko; Momohara, Arata; Yi, Si-Rong; Robertson, Kevin; Song, Kun; Zhang, Shi-Qiang; He, Long-Yuan

    2015-01-01

    A rare coniferous Tertiary relict tree species, Thuja sutchuenensis Franch, has survived in the Daba Mountains of southwestern China. It was almost eliminated by logging during the past century. We measured size and age structures and interpreted regeneration dynamics of stands of the species in a variety of topographic contexts and community associations. Forest communities containing T. sutchuenensis were of three types: (1) the Thuja community dominated by T. sutchuenensis, growing on cliffs; (2) the Thuja-Quercus-Cyclobalanopsis community dominated by T. sutchuenensis, Quercus engleriana and Cyclobalanopsis oxyodon, along with Fagus engleriana and Carpinus fargesiana, on steep slopes; (3) the Thuja-Tsuga-Quercus community dominated by T. sutchuenensis, Tsuga chinensis, and Quercus spinosa, on crest ridges. The established seedlings/saplings were found in limestone crevices, on scarred cliff-faces, cliff-edges, fallen logs, canopy gaps and forest margins. The radial growth rate was 0.5-1.1 mm per year. Its growth forms were distorted. It had strong sprouting ability after disturbances. The T. sutchuenensis population thrives on cliffs where there is little competition from other species because of harsh conditions and rockslide disturbances. It is shade-intolerant but stress-tolerant. Its regeneration has depended on natural disturbances. PMID:25928845

  20. Pliocene terrace gravels of the ancestral Yukon River near Circle, Alaska: Palynology, paleobotany, paleoenvironmental reconstruction and regional correlation

    USGS Publications Warehouse

    Ager, T.A.; Matthews, J.V., Jr.; Yeend, W.

    1994-01-01

    Gravels deposited by the ancestral Yukon River are preserved in terrace remnants on the margins of the Yukon River valley near the village of Circle in east-central Alaska. Plant fossils recovered from sandy silt lenses within these gravels include cones and needles of Picea and Larix and a variety of seeds. Seed types include several taxa which no longer grow in Alaska, such as Epipremnum, Prunus and Weigela. Pollen types recovered from these deposits represent tree and shrub taxa that grow in interior Alaska today, such as Picea, Larix, Betula and Alnus, as well as several taxa that no longer grow in interior Alaska today, such as Pinus, Tsuga, Abies and Corylus. Pollen of herb taxa identified include Gramineae, Cyperaceae, Caryophyllaceae, Compositae, Polemonium and Epilobium. The fossil flora from the gravels near Circle are similar and probably age-equivalent to the flora recovered from the Nenana Gravel in the Alaska Range 250 km to the south. Palynological and tectonic evidence summarized in this paper now suggests that the Nenana Gravel was deposited during the early and middle Pliocene. The presence of plant fossils of Tsuga, Abies, Pinus, Weigela and Prunus suggests that the mean annual temperature (MAT) of eastern interior Alaska during the early and middle Pliocene was perhaps 7-9??C warmer and less continental than today's MAT of -6.4??C. ?? 1994.

  1. Late-glacial and Holocene Vegetation and Climate Variability, Including Major Droughts, in the Sky Lakes Region of Southeastern New York State

    NASA Technical Reports Server (NTRS)

    Menking, Kirsten M.; Peteet, Dorothy M.; Anderson, Roger Y.

    2012-01-01

    Sediment cores from Lakes Minnewaska and Mohonk in the Shawangunk Mountains of southeastern New York were analyzed for pollen, plantmacrofossils, macroscopic charcoal, organic carbon content, carbon isotopic composition, carbon/nitrogen ratio, and lithologic changes to determine the vegetation and landscape history of the greater Catskill Mountain region since deglaciation. Pollen stratigraphy generally matches the New England pollen zones identified by Deevey (1939) and Davis (1969), with boreal genera (Picea, Abies) present during the late Pleistocene yielding to a mixed Pinus, Quercus and Tsuga forest in the early Holocene. Lake Minnewaska sediments record the Younger Dryas and possibly the 8.2 cal kyr BP climatic events in pollen and sediment chemistry along with an 1400 cal yr interval of wet conditions (increasing Tsuga and declining Quercus) centered about 6400 cal yr BP. BothMinnewaska andMohonk reveal a protracted drought interval in themiddle Holocene, 5700-4100 cal yr BP, during which Pinus rigida colonized the watershed, lake levels fell, and frequent fires led to enhanced hillslope erosion. Together, the records show at least three wet-dry cycles throughout the Holocene and both similarities and differences to climate records in New England and central New York. Drought intervals raise concerns for water resources in the New York City metropolitan area and may reflect a combination of enhanced La Niña, negative phase NAO, and positive phase PNA climatic patterns and/or northward shifts of storm tracks.

  2. Fiber 3.0: An ecological growth model for northeastern forest types. Forest Service general technical report (Final)

    SciTech Connect

    Solomon, D.S.; Herman, D.A.; Leak, W.B.

    1995-05-22

    Fiber, a stand projection growth model, simulates the growth and structural development of stands in the Northeast. The internal structure of the model is specified and constructed by the ecological type classifications of sugar maple--ash, beech--red maple, oad--white pine, spruce--fir, hemlock--spruce, and cedar--black spruce. Guidelines are provided on operational procedures for the major commercial species growing on these different ecologic land classifications for a range of even-aged and uneven-aged silvicultural treatments and harvesting schedules.

  3. Society needs MD-assisted death, Canadian-trained medical director of US right-to-die society says.

    PubMed Central

    Williams, L S

    1995-01-01

    The growth of an American organization that supports the right to die is proof that the public wants and needs physician-assisted death, says a University of Alberta alumnus who is medical director of the Hemlock Society. Dr. Richard MacDonald says he believes individual patients have the right to decide whether they want to live with a certain quality of life. Both the American Medical Association and the CMA have spoken out against physician-assisted death, but MacDonald says this opposition is out of touch with the opinions of individual physicians and patients. PMID:7804922

  4. Euthanasia and physician assisted suicide; a social work update.

    PubMed

    Smokowski, P R; Wodarski, J S

    1996-01-01

    Considering the recent actions of Dr. Jack Kevorkian, Dr. Timothy Quill and the Hemlock Society's initiatives for legalizing physician assisted suicide for special cases in the state of Washington, Oregon, and California, arguments for and against euthanasia and physician assisted suicide have grown into a substantial and impassioned debate. This paper outlines and analyzes salient issues within the controversy of legalizing physician assisted suicide for terminally ill patients. It highlights significant issues for state and federal policy formation and further suggests unique roles which medical social workers might play in developing and implementing a compassionate and reliable system for caring for the terminally ill. PMID:8839460

  5. Toxicity of pyrolysis gases from wood

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Huttlinger, N. V.; Oneill, B. A.; Kourtides, D. A.; Parker, J. A.

    1977-01-01

    The toxicity of the pyrolysis gases from nine wood samples was investigated. The samples of hardwoods were aspen poplar, beech, yellow birch, and red oak. The samples of softwoods were western red cedar, Douglas fir, western hemlock, eastern white pine, and southern yellow pine. There was no significant difference between the wood samples under rising temperature conditions, which are intended to simulate a developing fire, or under fixed temperature conditions, which are intended to simulate a fully developed fire. This test method is used to determine whether a material is significantly more toxic than wood under the preflashover conditions of a developing fire.

  6. AmeriFlux US-UMB Univ. of Mich. Biological Station

    SciTech Connect

    Curtis, Peter; Gough, Christopher

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-UMB Univ. of Mich. Biological Station. Site Description - The UMBS site is located within a protected forest owned by the University of Michigan. Arboreal composition of the forest consists of mid-aged northern hardwoods, conifer understory, aspen, and old growth hemlock. Logging of local white pines began in 1879. In successive years, several other species were harvested. Logging was discontinued in 1980 when the land became protected under the private ownership of the University of Michigan. Patchy low- to high-intensity wildfires occurred yearly from 1880 - 1920, essentially burning the entire region.

  7. AmeriFlux US-Ha1 Harvard Forest EMS Tower (HFR1)

    SciTech Connect

    Munger, J. William

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Ha1 Harvard Forest EMS Tower (HFR1). Site Description - The Harvard Forest tower is on land owned by Harvard University. The site is designated as an LTER site. Most of the surrounding area was cleared for agrigulture during European settlement in 1600-1700. The site has been regrowing since before 1900 (based on tree ring chronologies) and is now predominantly red oak and red maple, with patches of mature hemlock stand and individual white pine. Overstory trees were uprooted by hurricane in 1938. Climate measurements have been made at Harvard Forest since 1964.

  8. Characterization of baculoviruses from the Martignoni collection.

    PubMed

    Rohrmann, George F

    2013-09-01

    47 samples from the Martignoni baculovirus collection were characterized by PCR amplification of the lef-8 gene. This led to the identification of sequences from viruses that either were not present in the database, or had been identified, but not further characterized. These included an NPV and a GV from Pseudoletia (Mythimna) unipuncta, and NPVs from Coloradia pandora, the oak and hemlock looper (probably Lambdina sp.), Peridroma sp., the pine butterfly (probably Neophasia sp.), Hemileuca sp., Orgyia vetusta, and several Choristoneura sp. A phylogenetic tree was constructed relating these viruses to their closest relatives in the database. PMID:23628143

  9. Biogenic and thermogenic origins of natural gas in Cook Inlet basin, Alaska.

    USGS Publications Warehouse

    Claypool, G.E.; Threlkeld, C.N.; Magoon, L.B.

    1980-01-01

    Two types of natural gas occurences are present. The major reserves (1.8 x 1011m3) occur in shallow (less than 2.300 m), nonassociated dry gas fields that contain methane with del13C in the range of -63 to -56 per mil. These gas fields are in sandstones interbedded with coals, the gas fields are interpreted as biogenic in origin. Lesser reserves of natural gas are associated with oil in the deeper Hemlock Conglomerate at the base of the Tertiary section; associated gas contains methane with del13C of about -46 per mil. These gases are thermogenic in origin.- from Authors

  10. Poisonous plants: effects on embryo and fetal development.

    PubMed

    Panter, Kip E; Welch, Kevin D; Gardner, Dale R; Green, Benedict T

    2013-12-01

    Poisonous plant research in the United States began over 100 years ago as a result of livestock losses from toxic plants as settlers migrated westward with their flocks, herds, and families. Major losses were soon associated with poisonous plants, such as locoweeds, selenium accumulating plants, poison-hemlock, larkspurs, Veratrum, lupines, death camas, water hemlock, and others. Identification of plants associated with poisoning, chemistry of the plants, physiological effects, pathology, diagnosis, and prognosis, why animals eat the plants, and grazing management to mitigate losses became the overarching mission of the current Poisonous Plant Research Laboratory. Additionally, spin-off benefits resulting from the animal research have provided novel compounds, new techniques, and animal models to study human health conditions (biomedical research). The Poisonous Plant Research Laboratory has become an international leader of poisonous plant research as evidenced by the recent completion of the ninth International Symposium on Poisonous Plant Research held July 2013 in Hohhot, Inner Mongolia, China. In this article, we review plants that negatively impact embryo/fetal and neonatal growth and development, with emphasis on those plants that cause birth defects. Although this article focuses on the general aspects of selected groups of plants and their effects on the developing offspring, a companion paper in this volume reviews current understanding of the physiological, biochemical, and molecular mechanisms of toxicoses and teratogenesis. PMID:24339034

  11. The northern and southern sections of the western ca. 1880 Ma Circum-Superior Large Igneous Province, North America: The Pickle Crow dyke connection?

    NASA Astrophysics Data System (ADS)

    Minifie, Matthew J.; Kerr, Andrew C.; Ernst, Richard E.; Hastie, Alan R.; Ciborowski, T. Jake R.; Desharnais, Guy; Millar, Ian L.

    2013-08-01

    The ca. 1880 Ma Circum-Superior Large Igneous Province (LIP) consists of a number of discontinuous segments known to cover a significant portion of the margin of the Superior Province craton in North America. New geochemical and isotopic data from western segments of this LIP support a common origin for the these segments and suggest that magmatism in the Lake Superior region may have been fed through the ~ 600 km long Pickle Crow dyke from a source north of the Fox River Belt in northeastern Manitoba. The Fox River Belt, Pickle Crow dyke and sections of the Hemlock Formation in the Lake Superior region possess trace element signatures which are similar to those of more recent oceanic plateaux. The Hemlock Formation displays a heterogeneous geochemical signature. This chemical heterogeneity can in part be explained by lithospheric contamination and possibly by source heterogeneity. The tectonomagmatic setting in which these igneous rocks were formed could have involved a mantle plume. Evidence supporting a plume origin includes high MgO volcanic rocks, high calculated degrees of partial melting and geochemical signatures similar to those of oceanic plateaux.

  12. Entomopathogenic Fungi Associated with Exotic Invasive Insect Pests in Northeastern Forests of the USA

    PubMed Central

    Gouli, Vladimir; Gouli, Svetlana; Marcelino, José A. P.; Skinner, Margaret; Parker, Bruce L.

    2013-01-01

    Mycopathogens of economically important exotic invasive insects in forests of northeastern USA have been the subject of research at the Entomology Research Laboratory, University of Vermont, for the last 20 years. Elongate hemlock scale, European fruit lecanium, hemlock woolly adelgid and pear thrips were analyzed for the presence of mycopathogens, in order to consider the potential for managing these pests with biological control. Fungal cultures isolated from insects with signs of fungal infection were identified based on morphological characters and DNA profiling. Mycopathogens recovered from infected insects were subdivided into three groups, i.e., specialized entomopathogenic; facultative entomopathogens; ubiquitous opportunistic contaminants. Epizootics were caused by fungi in the specialized group with the exception of M. microspora, P. marquandii and I. farinosa. Inoculation of insects in laboratory and field conditions with B. bassiana, L. muscarium and Myriangium sp. caused insect mortality of 45 to 95%. Although pest populations in the field seemed severely compromised after treatment, the remnant populations re-established themselves after the winter. Although capable of inducing high mortality, a single localized aerial application of a soil-dwelling fungus does not maintain long-time suppression of pests. However, it can halt their range expansion and maintain populations below the economic threshold level without the use of expensive insecticides which have a negative impact on the environment. PMID:26462527

  13. The diagenetic behavior of cutin acids in buried conifer needles and sediments from a coastal marine environment

    SciTech Connect

    Goni, M.A.; Hedges, J.I. )

    1990-11-01

    Whole green, litter, and sedimentary fir, hemlock, and cedar needles and bulk sediments collected from the Dabob Bay region in Washington state were analyzed for their cutin-derived CuO reaction products. Cutin acids accounted for {approximately}3% of tissue C in green needles, {approximately}4% in needle litter, 0.5-1.5% in sedimentary needles, and about 0.1% of the organic carbon (OC) in bulk sediments. Approximately 80% of the original cutin acids in fresh green needles were lost from the deepest ({approximately}100 years old) sedimentary tissues. Cutin was more reactive than lignin and polysaccharides, but more stable than the cyclitol components of the same needles. Comparative diagenetic losses of the individual cutin acids were not uniform and suggest that additional hydroxy groups and the presence of C double bonds both increase overall reactivity. Diagenetically induced changes in the various cutin parameters used to characterize nonwoody vascular plant tissues were not large enough to confuse degraded conifer tissues with other cutin sources. Based on these trends, the finely disseminated cutin-bearing tissues in Dabob Bay sediments appear to be comprised approximately of equal amounts of highly degraded fir/hemlock and cedar needle fragments. According to this estimate, nonwoody vascular plant debris accounted for roughly 15% of the total organic matter present in these sediments.

  14. Pushed to the limit: consequences of climate change for the Araucariaceae: a relictual rain forest family

    PubMed Central

    Offord, Catherine A.

    2011-01-01

    Background and Aims Under predicted climate change scenarios, increased temperatures are likely to predispose trees to leaf and other tissue damage, resulting in plant death and contraction of already narrow distribution ranges in many relictual species. The effects of predicted upward temperatures may be further exacerbated by changes in rainfall patterns and damage caused by frosts on trees that have been insufficiently cold-hardened. The Araucariaceae is a relictual family and the seven species found in Australia have limited natural distributions characterized by low frost intensity and frequency, and warm summer temperatures. The temperature limits for these species were determined in order to help understand how such species will fare in a changing climate. Methods Experiments were conducted using samples from representative trees of the Araucariaceae species occurring in Australia, Agathis (A. atropurpurea, A. microstachya and A. robusta), Arauacaria (A. bidwilli, A. cunninghamii and A. heterophylla) and Wollemia nobilis. Samples were collected from plants grown in a common garden environment. Lower and higher temperature limits were determined by subjecting detached winter-hardened leaves to temperatures from 0 to –17 °C and summer-exposed leaves to 25 to 63 °C, then measuring the efficiency of photosystem II (Fv/Fm) and visually rating leaf damage. The exotherm, a sharp rise in temperature indicating the point of ice nucleation within the cells of the leaf, was measured on detached leaves of winter-hardened and summer temperature-exposed leaves. Key Results Lower temperature limits (indicated by FT50, the temperature at which PSII efficiency is 50 %, and LT50 the temperature at which 50 % visual leaf damage occurred) were approx. –5·5 to –7·5 °C for A. atropurpurea, A. microstachya and A. heterophylla, approx. –7 to –9 °C for A. robusta, A. bidwillii and A. cunninghamii, and –10·5 to –11 °C for W. nobilis. High temperature damage began at 47·5 °C for W. nobilis, and occurred in the range 48·5–52 °C for A. bidwillii and A. cunninghamii, and in the range 50·5–53·5 °C for A. robusta, A. microstachya and A. heterophylla. Winter-hardened leaves had ice nucleation temperatures of –5·5 °C or lower, with W. nobilis the lowest at –6·8 °C. All species had significantly higher ice nucleation temperatures in summer, with A. atropurpurea and A. heterophylla forming ice in the leaf at temperatures >3 °C higher in summer than in winter. Wollemia nobilis had lower FT50 and LT50 values than its ice nucleation temperature, indicating that the species has a degree of ice tolerance. Conclusions While lower temperature limits in the Australian Araucariaceae are generally unlikely to affect their survival in wild populations during normal winters, unseasonal frosts may have devastating effects on tree survival. Extreme high temperatures are not common in the areas of natural occurrence, but upward temperature shifts, in combination with localized radiant heating, may increase the heat experienced within a canopy by at least 10 °C and impact on tree survival, and may contribute to range contraction. Heat stress may explain why many landscape plantings of W. nobilis have failed in hotter areas of Australia. PMID:21727080

  15. Identification of Begomoviruses Infecting Crops and Weeds in Belize

    PubMed Central

    McLaughlin, Pamela D.; McLaughlin, Wayne A.; Maxwell, Douglas P.; Roye, Marcia E.

    2010-01-01

    Plants including pepper, red kidney bean, squash, string bean and tomato, as well as weeds with viral symptoms were collected from five districts in Belize over a three year period with the aim of determining the diversity of the begomoviruses present. Sixty five percent of the samples screened via DNA hybridization produced signals indicative of begomovirus infection. Subsequent PCR amplifications and nucleotide sequence analyses revealed the presence of four begomoviruses in Belize. Pepper golden mosaic virus and Tomato mottle virus-[Flo] were found associated with tomato and sweet pepper and the former was also isolated from hot pepper. Merremia mosaic virus was found infecting hot pepper, sweet pepper and the weed species Euphorbia heterophylla. Euphorbia mosaic virus-[Yucatan Peninsula] was found in hot pepper and Euphorbia. This is the first report of the identification of begomoviruses in Belize. PMID:20596296

  16. Sixteen polymorphic microsatellite markers for a federally threatened species, Hexastylis naniflora (Aristolochiaceae), and co-occurring congeners1

    PubMed Central

    Hamstead, Jacqueline W.; Snider, Brandon L.; Oaks, Robyn; Fitzgerald, Evan; Woodward, Jason; Teat, Alyssa; Hay, Nikolai M.; Estep, Matt C.; Murrell, Zack E.

    2015-01-01

    Premise of the study: Twenty microsatellite loci were developed for the federally threatened species Hexastylis naniflora (Aristolochiaceae) to examine genetic diversity and to distinguish this species from co-occurring congeners, H. heterophylla and H. minor. Methods and Results: Next-generation sequencing approaches were used to identify microsatellite loci and design primers. One hundred fifty-two primer pairs were screened for repeatability, and 20 of these were further characterized for polymorphism. In H. naniflora, the number of alleles identified for polymorphic loci ranged from two to 23 (mean ∼8.8), with a mean heterozygosity of 0.39. Conclusions: These 16 polymorphic primers for H. naniflora will be useful tools in species identification and quantifying genetic diversity within the genus. PMID:26191466

  17. Corroborating molecular species discovery: Four new pine-feeding species of Chionaspis (Hemiptera, Diaspididae)

    PubMed Central

    Vea, Isabelle M.; Gwiazdowski, Rodger A.; Normark, Benjamin B.

    2013-01-01

    Abstract The genus Chionaspis (Hemiptera, Diaspididae) includes two North American species of armored scale insects feeding on Pinaceae: Chionaspis heterophyllae Cooley, and Chionaspis pinifoliae (Fitch). Despite the economic impact of conifer-feeding Chionaspis on horticulture, the species diversity in this group has only recently been systematically investigated using samples from across the group’s geographic and host range. This paper provides morphological recognition characters for four new species that were recently hypothesized to exist on the basis of molecular evidence. The new species, here described, are Chionaspis brachycephalon Vea sp. n., Chionaspis caudata Vea sp. n., Chionaspis sonorae Vea sp. n. and Chionaspis torreyanae Vea sp. n.  One of the new species, Chionaspis caudata Vea, has a gland spine at the apex of the pygidium, between the median lobes, unlike any other species of Chionaspis. An identification key to the species of Chionaspis feeding on pine in North America is provided. PMID:23717184

  18. Chemical constituents of Brazilian propolis and their cytotoxic activities.

    PubMed

    Banskota, A H; Tezuka, Y; Prasain, J K; Matsushige, K; Saiki, I; Kadota, S

    1998-07-01

    The EtOAc-soluble fraction of the MeOH extract of propolis afforded a new prenylated chromane derivative, 3-hydroxy-2, 2-dimethyl-8-prenylchromane-6-propenoic acid (1), along with 22 known compounds, 2-23. Of the known compounds, 4, 7, 12-19, and 22 were isolated for the first time from propolis, and the absolute configuration of 23 was established as (2S,3R). Investigation suggested that Baccharis spp. are a significant source of tropical Brazilian propolis, in addition to Clusia minor, Clusia major, and Araucaria heterophylla. All the compounds were tested for their cytotoxicity toward human HT-1080 fibrosarcoma and murine colon 26-L5 carcinoma cells. Among these compounds, 9 and 19-21 showed potent cytotoxicity, having ED50 values equal to or less than 10 microg/mL. PMID:9677271

  19. Lectins but not antifungal proteins exhibit anti-nematode activity.

    PubMed

    Zhao, S; Guo, Y X; Liu, Q H; Wang, H X; Ng, T B

    2009-09-01

    A variety of lectins and antifungal proteins were tested for toxicity against the plant parasitic nematodes Ditylenchus dipsaci and Heterodera glycines. It was found that lectins from the mushrooms Xylaria hypoxylon, Agrocybe cylindracea and Tricholoma mongolicum (TML-1) were the most potent against D. dipsaci, with EC(50) being 4.7, 9, and 20mg/ml, respectively. Lectins from Pseudostellaria heterophylla, samta tomato, and the mushrooms T. mongolicum (TML-2), Ganoderma lucidum, and Boletus edulis, and antifungal proteins from Ginkgo biloba toward D. dipsaci and pumpkin Cucurbita moschata had much lower anti-nematode potencies and could be considered as inactive for practical purposes. All lectins except that from P.heterophylle were potent against H.glycines. PMID:21784014

  20. Transcriptome Analysis and Gene Expression Profiling of Abortive and Developing Ovules during Fruit Development in Hazelnut

    PubMed Central

    Cheng, Yunqing; Liu, Jianfeng; Zhang, Huidi; Wang, Ju; Zhao, Yixin; Geng, Wanting

    2015-01-01

    Background A high ratio of blank fruit in hazelnut (Corylus heterophylla Fisch) is a very common phenomenon that causes serious yield losses in northeast China. The development of blank fruit in the Corylus genus is known to be associated with embryo abortion. However, little is known about the molecular mechanisms responsible for embryo abortion during the nut development stage. Genomic information for C. heterophylla Fisch is not available; therefore, data related to transcriptome and gene expression profiling of developing and abortive ovules are needed. Methodology/Principal Findings In this study, de novo transcriptome sequencing and RNA-seq analysis were conducted using short-read sequencing technology (Illumina HiSeq 2000). The results of the transcriptome assembly analysis revealed genetic information that was associated with the fruit development stage. Two digital gene expression libraries were constructed, one for a full (normally developing) ovule and one for an empty (abortive) ovule. Transcriptome sequencing and assembly results revealed 55,353 unigenes, including 18,751 clusters and 36,602 singletons. These results were annotated using the public databases NR, NT, Swiss-Prot, KEGG, COG, and GO. Using digital gene expression profiling, gene expression differences in developing and abortive ovules were identified. A total of 1,637 and 715 unigenes were significantly upregulated and downregulated, respectively, in abortive ovules, compared with developing ovules. Quantitative real-time polymerase chain reaction analysis was used in order to verify the differential expression of some genes. Conclusions/Significance The transcriptome and digital gene expression profiling data of normally developing and abortive ovules in hazelnut provide exhaustive information that will improve our understanding of the molecular mechanisms of abortive ovule formation in hazelnut. PMID:25836368

  1. Naturally occurring insect growth regulators. II. Screening of insect and plant extracts as insect juvenile hormone mimics.

    PubMed

    Jacobson, M; Redfern, R E; Mills, G D

    1975-01-01

    Ethereal extracts prepared from the larvae, pupae, or eggs of 10 species of insects and from various parts of 343 species of higher plants were screened for juvenilizing effects against Tenebrio molitor and Oncopeltus fasciatus. Activity in both species was shown by an extract of the larvae of the stable fly, Stomoxys calcitrans, whereas an extract of the pupae was active in O. fasiatus only. Extracts of two plant species (Echinacea angustifolia roots and Chamaecyparis lawsoniana seeds) showed high juvenilizing activity in T. MOLITOR, AND EXtracts of five plant species (Clethra alnifolia stems, leaves, and fruits, Sassafras albidum roots and root bark, Eucalyptus camaldulensis stems and bark, Pinus rigida twigs and leaves, and Iris douglasiana roots, stems, and fruits) were highly active in O. fasciatus an extract of Tsuga canadensis leaves showed lower activity in this insect. Extracts of 16 species of plants showed high insecticidal activity (mortality) in O. fasciatus but lacked juvenilizing properties in both species of test insects. PMID:1221244

  2. AMS radiocarbon dating of wood trunks in the pumiceous deposits of the Kikai-Akahoya eruption in Yakushima Island, SW Japan

    NASA Astrophysics Data System (ADS)

    Okuno, Mitsuru; Nakamura, Toshio; Geshi, Nobuo; Kimura, Katsuhiko; Saito-Kokubu, Yoko; Kobayashi, Tetsuo

    2013-01-01

    Radiocarbon dating using accelerator mass spectrometry (AMS) was performed on numerous wood trunks from pumiceous deposits along the Nagata, Isso and Miyanoura rivers on the northern side of Yakushima Island, 60 km south of Kyushu Island. The obtained 14C dates were around 6.5 ka BP, which, in combination with the geological characteristics of the pumiceous deposits indicates that these specimens were buried during the Kikai-Akahoya (K-Ah) eruption from the Kikai caldera. However, the fact that they are not charred suggests that the origin of these deposits are not pyroclastic flows. Fourteen taxa (Pinus subgen. Diploxylon, Tsuga, Cryptomeria, Chamaecyparis, Myrica, Castanea, Castanopsis, Quercus subgen. Cyclobalanopsis, Trochodendron, Phellodendron, Lagerstroemia, Rhododendron, Myrsine and Symplocos) were identified through anatomical characteristics. This is the first discovery of forest species on the Yakushima Island before the devastating eruption.

  3. Inhibition of methane consumption in forest soils by monoterpenes

    SciTech Connect

    Amaral, J.A.; Knowles, R.

    1998-04-01

    Selected monoterpenes were tested for their ability to inhibit atmospheric methane consumption by three forest soils from different vegetation types and by the cultured methanotrophic strain, Methylosinus trichosporium OB3b. Subsurface soil from coniferous (Pinus banksiana), deciduous (Populus tremuloides), and mixed hardwood (Tsuga canadensis and Prunus pensylvanica) stands was used under field-moist and slurry conditions. Most of the hydrocarbon monoterpenes tested significantly inhibited methane consumption by soils at environmentally relevant levels, with ({minus})-{alpha}-pinene being the most effective. With the exception of {beta}-myrcene, monoterpenes also strongly inhibited methane oxidation by Methylosinus trichosporium OB3b. Carbon dioxide production was stimulated in all of the soils by the monoterpenes tested. In one case, methane production was stimulated by ({minus})-{alpha}-pinene in an intact, aerobic core. Oxide and alcohol monoterpenoids stimulated methane production. Thus, monoterpenes appear to be potentially important regulators of methane consumption and carbon metabolism in forest soils.

  4. Modern pollen deposition in Long Island Sound

    USGS Publications Warehouse

    Beuning, Kristina R.M.; Fransen, Lindsey; Nakityo, Berna; Mecray, Ellen L.; Bucholtz ten Brink, Marilyn R.

    2000-01-01

    Palynological analyses of 20 surface sediment samples collected from Long Island Sound show a pollen assemblage dominated by Carya, Betula, Pinus, Quercus, Tsuga, and Ambrosia, as is consistent with the regional vegetation. No trends in relative abundance of these pollen types occur either from west to east or associated with modern riverine inputs throughout the basin. Despite the large-scale, long-term removal of fine-grained sediment from winnowed portions of the eastern Sound, the composition of the pollen and spore component of the sedimentary matrix conforms to a basin-wide homogeneous signal. These results strongly support the use of select regional palynological boundaries as chronostratigraphic tools to provide a framework for interpretation of the late glacial and Holocene history of the Long Island Sound basin sediments.

  5. The Pine Bark Adelgid, Pineus strobi, Contains Two Novel Bacteriocyte-Associated Gammaproteobacterial Symbionts

    PubMed Central

    Toenshoff, Elena R.; Szabó, Gitta; Gruber, Daniela

    2014-01-01

    Bacterial endosymbionts of the pine bark adelgid, Pineus strobi (Insecta: Hemiptera: Adelgidae), were investigated using transmission electron microscopy, 16S and 23S rRNA-based phylogeny, and fluorescence in situ hybridization. Two morphologically different symbionts affiliated with the Gammaproteobacteria were present in distinct bacteriocytes. One of them (“Candidatus Annandia pinicola”) is most closely related to an endosymbiont of Adelges tsugae, suggesting that they originate from a lineage already present in ancient adelgids before the hosts diversified into the two major clades, Adelges and Pineus. The other P. strobi symbiont (“Candidatus Hartigia pinicola”) represents a novel symbiont lineage in members of the Adelgidae. Our findings lend further support for a complex evolutionary history of the association of adelgids with a phylogenetically diverse set of bacterial symbionts. PMID:24271164

  6. Mapped plant macrofossil and pollen records of late Quaternary vegetation change in eastern North America

    SciTech Connect

    Jackson, S.T.; Overpeck, J.T.; Webb, T. III ||

    1995-06-01

    We compiled a plant macrofossil database for 12 eastern North American tree and shrub taxa (Picea sp., P. glauca, P. mariana, Larix laricina, Abies balsamea, Tsuga canadensis, Pinus strobus, P. banksiana, P. resinosa, Betula papyrifera, B. alleghaniensis, B. Series Humiles) at 264 late Quaternary sites. Presence/absence maps for these taxa at 18,000, 15,000, 12,000, 9000, 6000, 3000, and 0 {sup 14}C yr B.P. show changes in geographic ranges of these species in response to climatic change. Comparison of the macrofossil maps with isopoll maps for corresponding taxa corroborates inferences from the pollen data, and reveals species-level patterns not apparent in the pollen maps.

  7. Human-ecosystem interactions in relation to Holocene environmental change in Port Joli Harbour, southwestern Nova Scotia, Canada

    NASA Astrophysics Data System (ADS)

    Neil, Karen; Gajewski, Konrad; Betts, Matthew

    2014-03-01

    A high-resolution pollen record from Path Lake in Port Joli Harbour, Nova Scotia, Canada, provides a paleo-ecological perspective on Holocene climate and vegetation variability within the context of local archaeological research. Pollen assemblages in the early Holocene reflect a post-glacial forest dominated by Pinus, Tsuga, Betula and Quercus. During this time, a lower frequency of radiocarbon dated cultural material suggests lower human settlement intensity. Shallow water aquatic (Isoetes) and wetland (Alnus, Sphagnum) taxa increased after 3400 cal yr BP in response to a transition towards wetter climatic conditions. Culturally significant periods, where settlement intensity increased in the Maritimes and Maine, coincide with maximum values of reconstructed total annual precipitation, suggesting that environmental conditions may have influenced prehistoric human activity. European settlement, after 350 cal yr BP, was marked by a rise in Ambrosia. The impact of anthropogenic fire disturbances on the landscape was evidenced by peak charcoal accumulations after European settlement.

  8. Mapped plant-macrofossil and pollen records of late quaternary vegetation change in Eastern North America

    NASA Astrophysics Data System (ADS)

    Jackson, Stephen T.; Overpeck, Jonathan T.; Webb-, Thompson; Keattch, Sharen E.; Anderson, Katherine H.

    Macrofossil presence/absence maps and isopoll maps in 3000-year intervals show how ranges and abundance maxima for 12 eastern North American tree and shrub taxa ( Picea, P. glauca, P. mariana, Larix laricina, Abies balsamea, Tsuga canadensis, Pinus strobus, P. resinosa, P. banksiana, Betula papyrifera, B. alleghaniensis, B. Series Humiles) have changed from the last glacial maximum to the present. The macrofossil maps corroborate patterns shown by the isopoll maps and provide spatial detail and taxonomic resolution. The macrofossils confirm the inference from pollen data that unglaciated southeastern North America was cooler during the last glacial maximum (18 and 15 ka) than simulated by the COHMAP experiments with the NCAR CCM0 general circulation model. The geographic distribution of macrofossil occurrences during the Late glacial (12 and 9 ka) indicate that migration lag of boreal species did not occur at regional to subcontinental scales, and that pollen assemblages lacking modern analogs resulted from climate gradients lacking modern analogs. Early Holocene (9 and 6 ka) macrofossil maps show rapid northward expansion of tree species ranges into deglaciated regions. The data also show modest contractions of northern range limits of temperate species and expansions of southern range limits of boreal species in response to cooling trends during the late Holocene (3 and 0 ka). Comparison of modern macrofossil maps of nine of these taxa with corresponding range maps confirm that the macrofossils record the geographic ranges accurately. Comparison of the modern macrofossil maps with maps of tree growing-stock volume shows that for some taxa ( Abies, Tsuga) macrofossil occurrences were most frequent in regions of maximum tree abundance. Comparison of modern isopoll maps with the modern range and growing-stock volume maps indicate that, in contrast to the macrofossil data, the pollen data provide poorer resolution of range limits for most taxa, but better indications of abundance maxima and minima within the ranges.

  9. Holocene Asian monsoon evolution revealed by a pollen record from an alpine lake on the southeastern margin of the Qinghai-Tibetan Plateau, China

    NASA Astrophysics Data System (ADS)

    Zhang, E.; Wang, Y.; Sun, W.; Shen, J.

    2015-10-01

    We present the results of pollen analyses from a 1105-cm-long sediment core from Wuxu Lake in southwestern China, which depict the variations of the East Asian winter monsoon (EAWM) and the Indian summer monsoon (ISM) during the last 12.3 ka. During the period of 12.3 to 11.3 cal ka BP, the dominance of Betula forest and open alpine shrub and meadow around Wuxu Lake indicates a climate with relatively cold winters and dry summers, corresponding to the Younger Dryas event. Between 11.3 and 10.4 cal ka BP, further expansion of Betula forest and the retreat of alpine shrubs and meadows reflect a greater seasonality with cold winters and gradually increasing summer precipitation. From 10.4 to 4.9 cal ka BP, the dense forest understory, together with the gradual decrease in Betula forest and increase in Tsuga forest, suggest that the winters became warmer and summer precipitation was at a maximum, corresponding to the Holocene climatic optimum. Between 4.9 and 2.6 cal ka BP, Tsuga forest and alpine shrubs and meadows expanded significantly, reflecting relatively warm winters and decreased summer precipitation. Since 2.6 cal ka BP, reforestation around Wuxu Lake indicates a renewed strengthening of the ISM in the late Holocene; however, the vegetation in the catchment may also have been affected by grazing activity during this period. The results of our study are generally consistent with previous findings; however, the timing and duration of the Holocene climatic optimum from different records are inconsistent, reflecting real contrast in local rainfall response to the ISM. Overall, the EAWM is broadly in-phase with the ISM on the orbital timescale, and both monsoons exhibit a trend of decreasing strength from the early to late Holocene, reflecting the interplay of solar insolation receipt between the winter and summer seasons and El Niño Southern Oscillation strength in the tropical Pacific.

  10. High-level expression, purification and production of the fungal immunomodulatory protein-gts in baculovirus-infected insect larva.

    PubMed

    Wu, Tzong-Yuan; Chen, Hsin-An; Li, Feng-Yin; Lin, Ching-Ting; Wu, Chi-Ming; Hsieh, Feng-Chia; Tzen, Jason Tze-Cheng; Hsieh, Sheng-Kuo; Ko, Jiunn-Liang; Jinn, Tzyy-Rong

    2013-02-01

    Fip-gts, a fungal immunomodulatory protein (Fip) isolated from Ganoderma tsugae (gts), has been reported to possess therapeutic effects in the treatment of cancer and autoimmune disease. To cost-effectively produce Fip-gts and bypass the bottleneck involved in its time-consuming purification from G. tsugae, in this study, we incorporated the SP(bbx) secretion signal into recombinant baculovirus for expressing glycosylated and bioactive rFip-gts in baculovirus-infected insect cells and Trichoplusia ni larva. This is the first study to employ the aerosol infecting T. ni larva with recombinant baculovirus for economical and high-level production of foreign proteins. In this study, one purification could yield 10 mg of rFip-gts protein merely from ∼100 infected T. ni larvae by aerosol inoculation, corresponding to 5 L (5 × 10⁹ cells) of the infected Sf21 culture. In addition, the rFip-gts purified from T. ni larvae could induce the expression of interleukin-2 in murine splenocytes with an immunoresponsive level similar to that induced by LZ-8 (a known potent immunomodulatory protein purified from Ling zhi, Ganoderma lucidum). Thus, our results demonstrated that the larva-based baculovirus expression system can successfully express rFip-gts with the assembling capability required for maintaining immunomodulatory and anticancer activity. Our approach will open a new avenue for the production of rFip-gts and facilitate the immunoregulatory activity of rFip-gts available in the future. PMID:23296801

  11. Holocene Asian monsoon evolution revealed by a pollen record from an alpine lake on the southeastern margin of the Qinghai-Tibetan Plateau, China

    NASA Astrophysics Data System (ADS)

    Zhang, Enlou; Wang, Yongbo; Sun, Weiwei; Shen, Ji

    2016-02-01

    We present the results of pollen analyses from a 1105 cm long sediment core from Wuxu Lake in southwestern China, which depict the variations of the East Asian winter monsoon (EAWM) and the Indian summer monsoon (ISM) during the last 12.3 ka. During the period of 12.3 to 11.3 cal ka BP, the dominance of Betula forest and open alpine shrub and meadow around Wuxu Lake indicates a climate with relatively cold winters and dry summers, corresponding to the Younger Dryas event. Between 11.3 and 10.4 cal ka BP, further expansion of Betula forest and the retreat of alpine shrubs and meadows reflect a greater seasonality with cold winters and gradually increasing summer precipitation. From 10.4 to 4.9 cal ka BP, the dense forest understory, together with the gradual decrease in Betula forest and increase in Tsuga forest, suggest that the winters became warmer and summer precipitation was at a maximum, corresponding to the Holocene climatic optimum. Between 4.9 and 2.6 cal ka BP, Tsuga forest and alpine shrubs and meadows expanded significantly, reflecting relatively warm winters and decreased summer precipitation. Since 2.6 cal ka BP, reforestation around Wuxu Lake indicates a renewed humid period in the late Holocene; however, the vegetation in the catchment may also have been affected by grazing activity during this period. The results of our study are generally consistent with previous findings; however, the timing and duration of the Holocene climatic optimum from different records are inconsistent, reflecting real contrast in local rainfall response to the ISM. Overall, the EAWM is broadly in-phase with the ISM on the orbital timescale, and both monsoons exhibit a trend of decreasing strength from the early to late Holocene, reflecting the interplay of solar insolation receipt between the winter and summer seasons and El Niño-Southern Oscillation strength in the tropical Pacific.

  12. Vegetation and climate during the last glacial maximum in Japan

    NASA Astrophysics Data System (ADS)

    Tsukada, Matsuo

    1983-03-01

    The Japanese Archipelago was almost entirely covered by coniferous forests during the last glacial maximum. Northern Hokkaido was distinguished by coniferous parkland and tundra vegetation, while southern Hokkaido and northernmost Honshu were covered by northern boreal coniferous forests consisting mainly of Picea jezoensis, Picea glehnii, Abies sachalinensis, and Larix gmelinii; Tsuga was missing from the forest. More diverse boreal forests including species from Sakhalin and northern Japan grew together in northeastern Honshu. Central Honshu and the mountains of southwestern Japan supported subalpine coniferous forests which are now mainly restricted in distribution to the central mountains. Temperate coniferous forests ( Picea polita, Abies firma, and Tsuga sieboldii) existed principally in the modern mid-temperate and evergreen laurel-oak forest regions. Haploxylon pine and tree birch were also abundant in the boreal and cool-temperate zones, as was Diploxylon in the southern temperate zone. Significant populations of Fagus were found along the Pacific coasts of Kyushu and Shikoku, but they were too small to be defined as a beech forest zone. Quercetum mixtum ( Quercus, Ulmus, and Tilia) was more common in the coastal lowlands of southwestern Japan than those of northeastern Honshu; it was completely eliminated from Hokkaido. The reduced mean August temperature inferred from the floral assemblages showed a latitudinal gradient 20,000 yr ago; it was 8-9°C in northern Hokkaido, 7.7-8.7°C in northernmost Honshu, 7.2-8.4°C in the central mountains, 6.5°C in the Chugoku District, and 5-6°C in Kyushu. The probable annual precipitation ranged from 1050 to 1300 mm along coasts in southwestern Japan during the culmination of the last glaciation.

  13. Monitoring Forest Change and Ice Storm Disturbance to Forest Structure Using Echidna° Ground-Based Lidar

    NASA Astrophysics Data System (ADS)

    Yao, T.; Strahler, A. H.; Schaaf, C.; Yang, X.; zhao, F.; Woodcock, C. E.; Jupp, D. L.; Culvenor, D.; Lovell, J.; Newnham, G.; Li, X.; Wang, J.

    2011-12-01

    The ground-based, upward-scanning, near-infrared (1064 nm), full-waveform lidar, the Echidna° Validation Instrument (EVI), built by CSIRO Australia, is used to monitor forest change over a 2- or 3-year time period through changes in retrievals of mean stem diameter, stem density, basal area, above-ground standing biomass, leaf area index, foliage profile, and canopy height. The changes were validated by comparison with direct field measurements, or in the case of canopy height, with data from the Laser Vegetation Imaging Sensor (LVIS). Site-level EVI-retrieved values of mean DBH, stem count density, basal area and above-ground biomass matched the field measurements well, with R2 values of 0.84, 0.97, 0.96 and 0.98 respectively. Furthermore, the changes in EVI retrievals had the same trend as the change in field measurements over these 2-3 year periods. Based on five scans within each 1-ha plot, we focused on detecting forest change over a 2- or 3-year period at three New England forest stands: a second-growth conifer stand thinned as a shelterwood, an aging hemlock plantation, and a young second-growth hardwood stand. The first stand provided the opportunity to look for change in a stand containing many co-dominant and intermediate trees recently released by removal of selected over-story trees, while the other two stands suffered significant damage in an ice storm during the change period. At the shelterwood conifer site at Howland Experimental Forest, mean DBH, aboveground biomass, and leaf area index (LAI) all increased between 2007 and 2009. An ice storm struck the Harvard Forest in December, 2008, providing the opportunity to detect damage between 2007 and 2009 or 2010 with EVI scans at two sites : hemlock and hardwood. Retrieved leaf area index (LAI) was 13 percent lower in the hemlock site in 2009 and 10 percent lower in the hardwood site in 2010 as compared to 2007. The decrease of LAI quantifies a loss of biomass from the canopy, and broken tops were both recorded by the field teams and visible in the Echidna scans in the 2010 data. Stem density decreased and mean DBH increased at both sites, as smaller and weaker trees were felled by the ice. Canopy heights derived from the EVI-retrieved foliage profile closely matched those derived from the airborne Laser Vegetation Imaging Sensor (LVIS).

  14. Responses of Tree Seedlings to a Changing Atmosphere: Effects of Carbon Dioxide, Nitrogen Dioxide, and Ozone

    NASA Astrophysics Data System (ADS)

    Eller, A. S.; Sparks, J. P.

    2008-12-01

    Human activities have caused changes in the chemical composition of the atmosphere: the concentrations of carbon dioxide (CO2), nitrogen dioxide (NO2), and ozone (O3) have increased and are expected to continue increasing in the future. These gases have the potential to alter plant physiological processes, change growth rates, C:N, and carbon storage potential. The responses of tree seedlings to these changes will have a profound impact on the species composition and carbon storage potential of forests in the future. Others have found CO2 tends to increase plant growth and O3 to decrease it. NO2, if assimilated by plants, can be a source of nutrient nitrogen, but is also an oxidant with the potential to damage cell membranes and decrease growth. The objectives of this study were to determine the single and combined effects of CO2, NO2, and O3 on sugar maple, eastern hemlock, and two clones of trembling aspen. The trees were fumigated for two growing seasons with elevated (40ppb) or ambient NO2, elevated (560ppm) or ambient CO2, elevated (100 ppb 5 days/week) or ambient O3, and with or without additional soil nitrate (30 kg ha-1 yr-1) to simulate ecosystems with and without nitrogen limitation. We found that elevated CO2 increased total biomass of both maples and hemlocks. Further, the CO2 growth effect was most striking when combined with elevated O2; elevated CO2 eliminated the growth decrease induced by O3 especially when nitrogen was limited. Elevated NO2 had no effect on maple seedlings, but, similar to CO2, eliminated the decrease in growth under O3 on hemlock seedlings. The two aspen clones differed in their resistance to ozone. The non-resistant clone exhibited growth responses similar to maple. However, the resistant clone did not exhibit a growth response under any gas treatment regardless of soil nitrogen status. The variation in responses among species, within clones of the same species, and between fumigations was large in this study and suggests species level responses and exposure trials to combined gases will be necessary to parameterize future forest production models.

  15. The diagenetic behavior of cutin acids in buried conifer needles and sediments from a coastal marine environment

    NASA Astrophysics Data System (ADS)

    Goñi, Miguel A.; Hedges, John I.

    1990-11-01

    Whole green, litter, and sedimentary fir, hemlock, and cedar needles and bulk sediments collected from the Dabob Bay region in Washington state were analyzed for their cutin-derived CuO reaction products. All samples yielded dihydroxyhexadecanoic acid isomers (x,ω-C 16), 16-hydroxyhexa-decanoic acid (ω-C 16), 14-hydroxytetradecanoic acid (ω-C 14), and 18-hydroxyoctadec-9-enoic acid (ω-C 18: 1) as the major cutin acids. Fir/hemlock needle mixtures were characterized by a high abundance of the 9,16-dihydroxyhexadecanoic acid positional isomer, while cedar needles produced primarily the 10,16-dihydroxy counterpart. Cutin acids accounted for ~3% of tissue C in green needles, ~4% in needle litter, 0.5-1.5% in sedimentary needles, and about 0.1% of the organic carbon (OC) in bulk sediments. Approximately 80% of the original cutin acids in fresh green needles were lost from the deepest (~100 years old) sedimentary tissues. Cutin was more reactive than lignin and polysaccharides, but more stable than the cyclitol components of the same needles. Comparative diagenetic losses of the individual cutin acids were not uniform and suggest that additional hydroxy groups and the presence of C double bonds both increase overall reactivity. The relative stability series derived for all the molecular constituents measured is: total vanillyl phenols > total P- hydroxy phenols, ferulic acid, most aldoses, bulk organic matter > mannose, ω-C 14, ω-C 16 ⩾ ω-C 18:1 > glucose, p- coumaric acid, x, ω-C 16 > all cyclitols. Diagenetically induced changes in the various cutin parameters used to characterize nonwoody vascular plant tissues were not large enough to confuse degraded conifer tissues with other cutin sources. Based on these trends, the finely disseminated cutin-bearing tissues in Dabob Bay sediments appear to be comprised approximately of equal amounts of highly degraded fir/hemlock and cedar needle fragments. According to this estimate, nonwoody vascular plant debris accounted for roughly 15% of the total organic matter present in these sediments.

  16. Greenhouse Gas Exchange and Biogeochemistry of Fertilized Canadian Plantation Forests

    NASA Astrophysics Data System (ADS)

    Basiliko, N.; Grayston, S. J.; Roy, R.; Mohn, W. W.; Yolova, V.; Prescott, C.

    2005-12-01

    Canada's ratification of the Kyoto Protocol in 2002 has raised questions of the role of ecosystem management as a tool to temporarily reduce the net greenhouse gas burden of the forestry industry and potentially generate emission offset credits. We examined growing season methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) fluxes, soil nutrient chemistry, and microbial biomass and CH4-oxidizing bacterial communities in 20-year-old sub-boreal lodgepole pine and maritime hemlock plantations under control conditions and simulated operational fertilization with N (200kg urea-N per ha, applied twice) and N, P, K, and micronutrients. CH4 uptake was significantly greater in the lodgepole pine site than in the hemlock site (152-221 and 57-81 micrograms CH4 consumed per square meter per hour), and there were no significant differences among treatments at either site. Among sites, treatments, and sampling times, CH4 uptake correlated positively with NH4 concentrations and negatively with extractable organic N:P quotients, indicating that this process may potentially be limited by nutrient availability to the CH4-oxidizing bacteria. N2O efflux was measured sporadically at a few flux collars, but was not significantly different from zero at any site, treatment, or time. Soil respiration (CO2 efflux) rates were faster in the hemlock than lodgepole pine site (243-409 and 100-266 milligrams CO2 per square meter per hour), and significant treatment differences were observed at individual times, though with fertilized plots exhibiting both faster and slower rates than controls. Soil respiration correlated significantly with microbial biomass C and N and NO3. Within each site, soil respiration, but not CH4 uptake, was positively correlated with soil temperature. New experiments examining the short-term effects of fertilization on greenhouse gas exchanges are underway, and both short and long-term effects will be evaluated in relation to changes in C storage in plant biomass, litter, and soil organic matter under the same fertilized and control conditions.

  17. Palynology of latest Neogene (Middle Miocene to late Pliocene) strata in the Delmarva Peninsula of Maryland and Virginia

    USGS Publications Warehouse

    Sirkin, L.; Owens, J.P.

    1998-01-01

    Palynology of Miocene and Pliocene formations in the Delmarva Peninsula of Maryland and Virginia reveals a significant representation of exotic pollen interspersed in pollen assemblages that are otherwise comparable to those from the modern vegetation of the Mid-Alantic coastal plain region. The late Tertiary arboreal pollen (AP) assemblages are dominated by oak, hickory, pine, birch and alder with minor amounts of mid- and southern coastal tree taxa, as well as minor spruce and hemlock and a trace of fir. Nonarboreal pollen (NAP) include grass, sedge, composite and aquatic taxa. Exotic pollen in these assemblages represent plants now foreign to this region. They may be placed in three categories. First, there are extinct forms, such as Labrapollis, Plicatopollis, and Multiporopollenites, that can be traced from the Cretaceous or Early Tertiary into the Late Tertiary. The second group includes forms, such as Podocarpus, Engelhardtia, Pterocarya, Ephedra, Eucommia, Ulmus-Zelkova, Glyptostrobus, Palmae, and Cyathea, that are not found in this region today and not found in early Pleistocene sediments in the eastern United States. Many of these taxa are subtropical or greatly restricted in geographic range. A third group of exotics, mainly Cyrilla, Planera, Gordonia, Jussiaea, and Sapotacaea, including Minusops, are generally found south of the study area or have their northern limit here at this time. The lack of the extinct or distant exotics in early to mid-Pleistocene sediments in the mid-Atlantic coastal plain and the last appearance of Pterocarya, as the last exotic taxon in the early Pleistocene of western Europe, support the stratigraphic assignment of the Pliocene units. The number of exotic taxa diminish markedly between the Miocene pollen assemblages and those of the Late Pliocene. Climatic fluctuations characterize the Late Tertiary environments. The Miocene, for example, incorporates a warming trend between the upper, middle Miocene and the Manokin beds and the late Miocene of the Pokomoke beds. The late Miocene was probably somewhat warner than the present climate in the Delmarva region. This trend is based on the presence of colder climate indicators, mainly spruce and hemlock, in the Manokin pollen record. The two distinct pollen assemblages constitute two pollen zones. Similarly, the Pliocene pollen record also shows a warming trend. The pollen zone of the Yorktown Formation of the early Pliocene age contains the colder climate indicators spruce and hemlock. The Beaverdam and Walston formation of late Pliocene age contain pollen assemblages that reflect climatic conditions warmer than the present time.

  18. Silicon production process evaluations

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Chemical engineering analysis of the HSC process (Hemlock Semiconductor Corporation) for producing silicon from dichlorosilane in a 1,000 MT/yr plant was continued. Progress and status for the chemical engineering analysis of the HSC process are reported for the primary process design engineering activities: base case conditions (85%), reaction chemistry (85%), process flow diagram (60%), material balance (60%), energy balance (30%), property data (30%), equipment design (20%) and major equipment list (10%). Engineering design of the initial distillation column (D-01, stripper column) in the process was initiated. The function of the distillation column is to remove volatile gases (such as hydrogen and nitrogen) which are dissolved in liquid chlorosilanes. Initial specifications and results for the distillation column design are reported including the variation of tray requirements (equilibrium stages) with reflux ratio for the distillation.

  19. Alkaloid-Containing Plants Poisonous to Cattle and Horses in Europe.

    PubMed

    Cortinovis, Cristina; Caloni, Francesca

    2015-12-01

    Alkaloids, nitrogen-containing secondary plant metabolites, are of major interest to veterinary toxicology because of their occurrence in plant species commonly involved in animal poisoning. Based on epidemiological data, the poisoning of cattle and horses by alkaloid-containing plants is a relatively common occurrence in Europe. Poisoning may occur when the plants contaminate hay or silage or when forage alternatives are unavailable. Cattle and horses are particularly at risk of poisoning by Colchicum autumnale (meadow saffron), Conium maculatum (poison hemlock), Datura stramonium (jimson weed), Equisetum palustre (marsh horsetail), Senecio spp. (ragwort and groundsel) and Taxus baccata (European yew). This review of poisonous alkaloid-containing plants describes the distribution of these plants, conditions under which poisoning occurs, active toxic principles involved and subsequent clinical signs observed. PMID:26670251

  20. A review of the silicon material task

    NASA Astrophysics Data System (ADS)

    Lutwack, R.

    1984-02-01

    The Silicon Material Task of the Flat-Plate Solar Array Project was assigned the objective of developing the technology for low-cost processes for producing polysilicon suitable for terrestrial solar-cell applications. The Task program comprised sections for process developments for semiconductor-grade and solar-cell-grade products. To provide information for deciding upon process designs, extensive investigations of the effects of impurities on material properties and the performance of cells were conducted. The silane process of the Union Carbide Corporation was carried through several stages of technical and engineering development; a pilot plant was the culmination of this effort. The work to establish silane fluidized-bed technology for a low-cost process is continuing. The advantages of the use of dichlorosilane is a siemens-type were shown by Hemlock Semiconductor Corporation. The development of other processes is described.

  1. Antifeedant compounds from three species of Apiaceae active against the field slug, Deroceras reticulatum (Muller).

    PubMed

    Birkett, Michael A; Dodds, Catherine J; Henderson, Ian F; Leake, Lucy D; Pickett, John A; Selby, Martin J; Watson, Peter

    2004-03-01

    Extracts of volatiles from foliage of three plants in the Apiaceae, Conium maculatum L. (hemlock), Coriandrum sativum L. (coriander), and Petroselinum crispum Mill. (Nym.) (parsley), previously shown to exhibit antifeedant activity in assays with the field slug, Deroceras reticulatum (Muller) (Limacidae: Pulmonata), were studied further to identify the active components. Coupled gas chromatography-mass spectrometry (GC-MS) and neurophysiological assays using tentacle nerve preparations resulted in the identification of 11 active compounds from the three extracts. Wheat flour feeding bioassays were used to determine which of these compounds had the highest antifeedant activity. One of the most active compounds was the alkaloid gamma-coniceine, from C. maculatum. The role of potentially toxic alkaloids as semiochemicals and the potential for using such compounds as crop protection agents to prevent slug feeding damage is discussed. PMID:15139308

  2. Alkaloid-Containing Plants Poisonous to Cattle and Horses in Europe

    PubMed Central

    Cortinovis, Cristina; Caloni, Francesca

    2015-01-01

    Alkaloids, nitrogen-containing secondary plant metabolites, are of major interest to veterinary toxicology because of their occurrence in plant species commonly involved in animal poisoning. Based on epidemiological data, the poisoning of cattle and horses by alkaloid-containing plants is a relatively common occurrence in Europe. Poisoning may occur when the plants contaminate hay or silage or when forage alternatives are unavailable. Cattle and horses are particularly at risk of poisoning by Colchicum autumnale (meadow saffron), Conium maculatum (poison hemlock), Datura stramonium (jimson weed), Equisetum palustre (marsh horsetail), Senecio spp. (ragwort and groundsel) and Taxus baccata (European yew). This review of poisonous alkaloid-containing plants describes the distribution of these plants, conditions under which poisoning occurs, active toxic principles involved and subsequent clinical signs observed. PMID:26670251

  3. Downed dead woody fuel and biomass in the Northern Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Brown, J. K.; See, T. E.

    1981-07-01

    Weights and volumes of downed woody material in diameter classes of one-fourth to 1, 1 to 3, and greater than 3 inches and forest floor duff depths were summarized from extensive inventories in nothern Idaho and Montana. Biomass loadings are shown by cover types and habitat types within National Forests. Total downed woody biomass ranged from 5 tons per acre in ponderosa pine to 33 tons per acre in cedar-hemlock. Loadings generally increased with increased productivity, but varied greatly with stand age. Fuels tended to become predictably high in overmature stands but unpredictable in young, immature, and mature stands. Forest fuel succession is discussed in relation to tree mortality, fuel buildup, and depletion.

  4. Evaluating the Contribution of Climate Forcing and Forest Dynamics to Accelerating Carbon Sequestration by Forest Ecosystems in the Northeastern U.S.: Final Report

    SciTech Connect

    Munger, J. William; Foster, David R.; Richardson, Andrew D.

    2014-10-01

    This report summarizes work to improve quantitative understanding of the terrestrial ecosystem processes that control carbon sequestration in unmanaged forests It builds upon the comprehensive long-term observations of CO2 fluxes, climate and forest structure and function at the Harvard Forest in Petersham, MA. This record includes the longest CO2 flux time series in the world. The site is a keystone for the AmeriFlux network. Project Description The project synthesizes observations made at the Harvard Forest HFEMS and Hemlock towers, which represent the dominant mixed deciduous and coniferous forest types in the northeastern United States. The 20+ year record of carbon uptake at Harvard Forest and the associated comprehensive meteorological and biometric data, comprise one of the best data sets to challenge ecosystem models on time scales spanning hourly, daily, monthly, interannual and multi-decadal intervals, as needed to understand ecosystem change and climate feedbacks.

  5. High pressure liquid jet for disintegration of wood: Technical progress report for the period May 1988--September 30, 1988

    SciTech Connect

    Not Available

    1988-01-01

    Most newsprint is made of a mixture of seventy to eighty percent ground wood, and twenty to thirty percent unbleached sulphite or semi-bleached sulphate pulp. Presently, spruce is the most desirable species for wood pulp production, with the true firs, western hemlock, and southern pine following in order. It is anticipated that the use of hardwoods in newsprint will increase with time. In the manufacture of wood pulp for paper production, conventional practice is to grind debarked logs using a revolving grindstone. The abrasive stone causes individual wood fibers and fiber bundles to be separated from the log. Water is added to the ground pulp, during grinding, through a shower pipe which sprays water on the periphery of the stone. This water adsorbs the frictional heat generated at the interface between the stone and the wood, washes the fibers from the surface of the stone, and controls the consistency of the resulting pulp. 6 refs., 2 figs., 2 tabs.

  6. Economics of polysilicon processes

    NASA Astrophysics Data System (ADS)

    Yaws, C. L.; Li, K. Y.; Chou, S. M.

    1986-02-01

    Techniques are being developed to provide lower cost polysilicon material for solar cells. Existing technology which normally provides semiconductor industry polysilicon material is undergoing changes and also being used to provide polysilicon material for solar cells. Economics of new and existing technologies are presented for producing polysilicon. The economics are primarily based on the preliminary process design of a plant producing 1,000 metric tons/year of silicon. The polysilicon processes include: Siemen's process (hydrogen reduction of trichlorosilane); Union Carbide process (silane decomposition); and Hemlock Semiconductor process (hydrogen reduction of dichlorosilane). The economics include cost estimates of capital investment and product cost to produce polysilicon via the technology. Sensitivity analysis results are also presented to disclose the effect of major paramentes such as utilities, labor, raw materials and capital investment.

  7. Sensitivity analysis for solar plates

    NASA Astrophysics Data System (ADS)

    Aster, R. W.

    1986-02-01

    Economic evaluation methods and analyses of emerging photovoltaic (PV) technology since 1976 was prepared. This type of analysis was applied to the silicon research portion of the PV Program in order to determine the importance of this research effort in relationship to the successful development of commercial PV systems. All four generic types of PV that use silicon were addressed: crystal ingots grown either by the Czochralski method or an ingot casting method; ribbons pulled directly from molten silicon; an amorphous silicon thin film; and use of high concentration lenses. Three technologies were analyzed: the Union Carbide fluidized bed reactor process, the Hemlock process, and the Union Carbide Komatsu process. The major components of each process were assessed in terms of the costs of capital equipment, labor, materials, and utilities. These assessments were encoded as the probabilities assigned by experts for achieving various cost values or production rates.

  8. Primary deforestation and regrowth on limestone slopes on Vancouver Island, British Columbia

    SciTech Connect

    Harding, K.A.; Ford, D.C. . Dept. of Geography)

    1992-01-01

    Limestones, well bedded and steeply dipping, are common in northern Vancouver Island. They have been glaciated and host a high density of postglacial karren (dissolution pits, grooves and troughs linked to underlying caves). There is rich, mature forest cover of western hemlock, silver fir and red cedar that is rooted in the karren or in overlying glacial deposits. Logging commenced around 1900 AD, intensifying after 1960 with clear cutting and (often) burning of slash. Impacts were investigated quantitatively by comparing sixteen limestone sites with eight on adjoining volcanic rocks. Some sites on each retained original forest, other were cleared. It was found that soil losses following logging are significantly greater on the limestones because of wash into karren (the epikarst zone). Regrowth is retarded on the limestones also; one site cleared in 1911 had regained approximately 17% of its original volume of timber 75 years later.

  9. Direct marine-continental correlation: 150,000-year oxygen isotope--pollen record from the north pacific.

    PubMed

    Heusser, L E; Shackleton, N J

    1979-05-25

    Core Y72 II I (43 degrees 15'N, 126 degrees 22'W) contains sediment of oxygen isotope stages I through 6 (substages 5a through 5e are well developed) and abundant pollen from the nearby continent, enabling us for the first time to obtain a direct marine-continental correlation of events in the last interglacial sensu lato. From stage 6 to substage 5e the vegetational record resembles that during the waning of the last glacial. During substage 5e, after a rapid increase of alder, western hemlock was abundant and significant amounts of redwood, oak, and Douglas fir appeared. These results suggest that vegetation on the adjacent continent during substage 5e was similar to that of the temperate conifer forests which developed in the Pacific Northwest during the Holocene. The vegetation record since that brief episode (which like the Eemian in northwest Europe lasted only afew thousand years) has been complex. PMID:17730526

  10. AmeriFlux US-Syv Sylvania Wilderness Area

    SciTech Connect

    Desai, Ankur

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Syv Sylvania Wilderness Area. Site Description - Old growth forest consisting primarily of sugar maple and eastern hemlock. Note that a small lake to the north and data analyses suggest that wind direction screening is appropriate (see Desai, A.R., Bolstad, P.V., Cook, B.D., Davis, K.J., and Carey, E.V., 2005. Comparing net ecosystem exchange of carbon dioxide between an old-growth and mature forest in the upper midwest, USA. Ag. For. Met. 128(1-2): 33-55 (doi: 10.1016/j.agrformet.2004). Site was chosen to represent an end member representative of the upland forests in the WLEF tall tower flux footprint. (Note, however, that old growth forests are not found within the WLEF tall tower flux footprint.)

  11. AmeriFlux US-Wrc Wind River Crane Site

    SciTech Connect

    Bible, Ken; Wharton, Sonia

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Wrc Wind River Crane Site. Site Description - Wind River Field Station flux tower site is located in the T.T. Munger Research Area of the Wind River Ranger District in the Gifford Pinchot National Forest. Protected since 1926, the T.T. Munger Research Natural Area (RNA) is administered by the USDA Forest Service Pacific Northwest Research Station and Gifford Pinchot National Forest. The Douglas-fir/western hemlock dominant stand is approximately 500 years old and represents end points of several ecological gradients including age, biomass, structural complexity, and density of the dominant overstory species. A complete stand replacement fire, approximately 450-500 years ago, resulted in the initial establishment. No significant disturbances have occurred since the fire aside from those confined to small groups of single trees, such as overturn from high wind activity and mechanical damage from winter precipitation.

  12. Production rates and costs of cable yarding wood residue from clearcut units

    SciTech Connect

    LeDoux, C.B.

    1984-01-01

    Calculations were made of the incremental production rates and costs for yarding and loading logging residue in clearcut old-growth Douglas fir/western hemlock forests in western Oregon. Three different cable yarding machines were used in various configurations: highlead, shotgun skyline (Flyer), running skyline, and skyline with haulback. Regression equations were developed for productive yarding time as a function of slope yarding distance, number of merchantable logs per turn and residue volume per turn. Average yarding production rate for turns containing both merchantable logs and residue was 1832 cubic feet per hectare at a cost of $0.18/cubic foot. Results show that residue was most efficiently yarded (and is close to costs of merchantable logs) when a turn contains 1-3 pieces of residue, totalling at least 15-20 cubic feet.

  13. Pioneer exotic tree search for the douglas-fir region. Forest Service general technical report

    SciTech Connect

    Silen, R.R.; Olson, D.L.

    1992-03-01

    After three-quarters of a century of introduction of 152 conifer and broadleaf species, no promising candidate exotic was found for the Douglas-fir region. Growth curves spanning 50 years or longer are figured for many species. Firs, pines, larches, spruces, hemlocks, and cedars orginating in northwestern North America had superior growth rates to those from other forest regions. The probable basis for these differences is discussed. The record highlights a general failure of introduced hardwoods, the slow decline of most introduced conifers, the long time needed to express failures, dramatic effects of climatic extremes or introduced pests, failure of native species of continental origin at Wind River, striking similarities of growth rate for the species originating in each country, and many important contrasts between results from early reports and long-term conclusions.

  14. A review of the silicon material task

    NASA Technical Reports Server (NTRS)

    Lutwack, R.

    1984-01-01

    The Silicon Material Task of the Flat-Plate Solar Array Project was assigned the objective of developing the technology for low-cost processes for producing polysilicon suitable for terrestrial solar-cell applications. The Task program comprised sections for process developments for semiconductor-grade and solar-cell-grade products. To provide information for deciding upon process designs, extensive investigations of the effects of impurities on material properties and the performance of cells were conducted. The silane process of the Union Carbide Corporation was carried through several stages of technical and engineering development; a pilot plant was the culmination of this effort. The work to establish silane fluidized-bed technology for a low-cost process is continuing. The advantages of the use of dichlorosilane is a siemens-type were shown by Hemlock Semiconductor Corporation. The development of other processes is described.

  15. Evaluating Paleoecological Patterns Using Paleoenvironmental Proxies: The Promise and the Peril

    NASA Astrophysics Data System (ADS)

    Jackson, S. T.; Booth, R. K.

    2007-12-01

    For the past seven years we have been studying the vegetational history of the western Great Lakes region in the context of mid- to late Holocene climate change and variability. Our work has included diverse archives and proxies for both paleoecological and paleoclimatic inference. The former consist of pollen, plant-macrofossil, and charcoal records from sediments of small lakes and peatlands. Paleoclimate inferences have been based on lake-level records, peatland-inception dates, dune and lakeshore dynamics, and paleohydrological reconstructions from ombrotrophic and kettle peatlands. Our greatest success has been in pairing lake-based paleoecological records with peatland-based paleohydrological records. Peatland hydrology is sensitive to annual and seasonal moisture variation, and peatland-sediment archives contain diverse proxies including testate-amoeba assemblages, humification, organic biomarkers, stable isotopes, and plant macrofossils. Our work has resolved old controversies while unveiling unforeseen patterns. Examples include: (1) A mid-Holocene decline in hemlock populations, long attributed to a pest/pathogen outbreak, coincided with a rapid, unprecedented drop in peatland water levels. However, the decline shows complex structure in time, both ecologically and climatically. Hemlock's final demise 5000 yr BP was preceded by several centuries of multidecadal hydrological fluctuation accompanied by time- lagged hemlock fluctuations. (2) A late Holocene decline in beech populations, variously attributed to human-set fires and the Little Ice Age, occurred during a series of severe multidecadal droughts. This event is also structured in time and space: in some areas the droughts were dampened and beech increased, and at sites where beech decline and droughts occurred, beech pollen, charcoal concentrations, and water-levels fluctuated dramatically between 1000 and 700 yr BP. (3) Yellow birch populations expanded rapidly across a broad swath of Upper Michigan and Wisconsin during an extended pluvial period (4000-3000 yr BP) that followed on a drought of extraordinary duration and severity (4200-4000 yr BP). Continued expansion of yellow birch, as well as hemlock and beech, after 3000 yr BP was mediated by edaphic mosaics and centennial-scale pluvial events. Our experience indicates that integrated paleoecological and paleoclimatological studies have payoffs for ecology, paleoecology, and paleoclimatology. Perils, though real, are no different from those encountered in other interdisciplinary enterprises in the historical sciences. We identify six key challenges for continued progress in this area: (1)identifying, refining, and applying paleoclimate proxies that are sensitive to the same climate variables and at the same timescales as the ecological systems of interest. (2) correlating events in time among records, particularly when paleoecological and paleoclimate data derive from different archives. (3) identifying and modeling lags in ecological response to climate forcings. (4) determining proximal mechanisms of past ecological responses to climate changes. (5) assessing indirect responses to climate forcing, and interactions between climate and other factors (e.g., pests, wildfires). (6) determining "when to quit" - when to conclude that climate forcing of an observed ecological event is insupportable (versus assuming that the proxies examined to date simply aren't sensitive to whatever the ecological system is responding to). Meeting these challenges will require engagement and collaboration among paleoecologists, paleoclimatologists, geochronologists, and ecologists.

  16. Ecosystem, location, and climate effects on foliar secondary metabolites of lodgepole pine populations from central British Columbia.

    PubMed

    Wallis, Christopher M; Huber, Dezene P W; Lewis, Kathy J

    2011-06-01

    Lodgepole pines, Pinus contorta Douglas ex Louden var. latifolia Engelm. ex S. Watson, are encountering increased abiotic stress and pest activity due to recent increases in temperature and changes in precipitation throughout their range. This tree species counters these threats by producing secondary metabolites, including phenolics and terpenoids. We examined foliar levels of lignin, soluble phenolics, monoterpenoids, sesquiterpenoids, and diterpenoids in 12 stands in British Columbia, Canada. We used these data to assess associations among foliar secondary metabolite levels and ecosystem, geographic, and climatic variables. Regressions were also performed to observe which combinations of variables best explained secondary metabolite variance. Stands of P. c. latifolia in the Coastal Western Hemlock and Interior Cedar/Hemlock biogeoclimatic zones had consistently greater foliar levels of almost all measured secondary metabolites than did other stands. Lignin was present in greater amounts in Boreal White/Black Spruce ecosystem (i.e., northern) stands than in southern stands, suggesting a role for this metabolite in pine survival in the boreal forest. Attempts to develop regression models with geographic and climatic variables to explain foliar secondary metabolite levels resulted in multiple models with similar predictive capability. Since foliar secondary metabolite levels appeared to vary most between stand ecosystem types and not as much due to geographic and climatic variables, metabolic profiles appeared best matched to the stress levels within local environments. It is unknown if differences in secondary metabolite levels are the result of genetic adaptation or phenotypic plasticity, but results from this and other studies suggest that both are important. These results are interpreted in light of ongoing efforts to assist in the migration of certain populations of P. c. latifolia northward in an effort to counter predicted effects of climate change. PMID:21537900

  17. Analysis of nrDNA sequences and microsatellite allele frequencies reveals a cryptic chanterelle species Cantharellus cascadensis sp. nov. from the American Pacific Northwest.

    PubMed

    Dunham, Susie M; O'Dell, Thomas E; Molina, Randy

    2003-10-01

    In the Pacific Northwest, yellow chanterelles have long been referred to as Cantharellus cibarius, synonymous with the European yellow chanterelle. Broad scale genetic surveys of North American chanterelles with C. cibarius-like morphology have demonstrated that the nrDNA internal transcribed spacer exhibits length variability, suggesting that this common morphology masks a species complex. Recently researchers have used morphological and genetic data to identify the yellow chanterelle most frequently harvested from American Pacific Northwest forests as C. formosus, a species once thought to be rare in the region. We present three genetic data sets and one morphological data set that characterize a previously undescribed, species of yellow chanterelle from the central Cascade Mountains of Oregon. Phylogenetic analyses of the nrDNA large subunit and ITS regions show that C. cascadensis sp. nov., along with two other yellow chanterelle taxa (C. cibarius var. roseocanus and European C. cibarius), are more closely related to white chanterelles (C. subalbidus) than they are to C. formosus. Data from five microsatellite loci provide evidence that C. formosus, C. subalbidus, and C. cascadensis sp. nov. do not interbreed when they co-occur spatially and temporally in Douglas fir-western hemlock forests. This demonstrates that these three sympatric chanterelles are biological species with boundaries congruent with those delineated by nrDNA phylogenetic clades. Morphological data indicate that the colour of the pileus and shape of the stipe can be used to separate fresh collections of the two yellow species now known to co-occur in Douglas fir-western hemlock forests in Oregon. PMID:14635765

  18. The problem of conifer species migration lag in the Pacific Northwest region since the last glaciation

    NASA Astrophysics Data System (ADS)

    Elias, Scott A.

    2013-10-01

    Multiproxy evidence indicates that warmer-than-present summers became established in Eastern Beringia as early as 14,000-13,000 years ago, but the dispersal of spruces, pines, cedars and hemlocks across the Pacific Northwest (PNW) region of southern Alaska did not begin until at least 1500 years afterwards, and took many thousands of years to be completed. There are many potential reasons for this slow spread of PNW conifers towards their modern range limits. The absence of mycorrhizae in the soils of southern Alaska may have slowed conifer establishment. The availability of soil moisture was another limiting factor. With the exception of Pinus contorta, the other PNW conifers become established most readily from seeds that fall on moist, shaded substrates, thus they are not good pioneering species. Competition with alder and birch played an important role, especially along Prince William Sound and the Kenai Peninsula. Alder or alder and birch dominated these regions until the mid- to late Holocene. The other key element for most PNW conifer species is the precipitation regime. The hemlocks, cedars and Sitka spruce are not drought-hardy. So although the PNW temperature regime may have been warm enough in early postglacial times to support the growth of PNW conifers, it was probably too dry for them to successfully become established in new regions. The conflation of these environmental factors limits our present understanding of the problem, but the recent trend of multi-proxy analysis in Quaternary paleoecology will certainly sharpen our reconstructions. Such proxies as conifer needle stomata and insect fossil remains hold significant promise.

  19. Free-living ciliates from epiphytic tank bromeliads in Mexico.

    PubMed

    Durán-Ramírez, Carlos Alberto; García-Franco, José Guadalupe; Foissner, Wilhelm; Mayén-Estrada, Rosaura

    2015-02-01

    The ciliate diversity of Mexican bromeliads is poorly known. We studied the ciliate community of two species of epiphytic tank bromeliads from 48 individuals of Tillandsia heterophylla and four of T. prodigiosa. The bromeliads occurred on over 22 tree host species. Samples were collected during 2009 and 2010 in a mountain cloud forest and in two coffee plantations and in a pine-oak forest. The ciliates were identified in live and protargol preparations. We recorded 61 ciliate species distributed in 39 genera grouped in eight classes. Ten species were frequent in the 52 samples (20 ± 3.2) and Leptopharynx bromeliophilus was the most frequent recorded in 25 samples. Thirty-three species are new for the fauna of Mexico, 24 species have been recorded for the first time in tank bromeliads. The classes Spirotrichea, Oligohymenophorea and Colpodea presented the highest number of species, 16, 14, and 12, respectively. Colpoda was the most species-rich genus being present with six species. A low similarity between areas and seasons was obtained with Jaccard's index. We conclude that the two bromeliads species host a rich ciliate diversity whose knowledge contributes to the question of ciliate distribution and specifically, in tank bromeliads. PMID:25497463

  20. In Vitro Screening of Medicinal Plants Used in Mexico as Antidiabetics with Glucosidase and Lipase Inhibitory Activities

    PubMed Central

    Ramírez, Guillermo; Zavala, Miguel; Pérez, Julia; Zamilpa, Alejandro

    2012-01-01

    This work shows the inhibitory effect on glucosidase and lipase enzymes of 23 medicinal plants described as traditional treatments for diabetes in several Mexican sources. Hydroalcoholic extracts of selected plants were evaluated at 1 mg/mL for glucosidase and 0.25 mg/mL for lipase inhibitory activities, respectively. Camellia sinensis, acarbose, and orlistat were used as positive controls. Dose-response curves were done with the most active species. Sixty percent of all tested extracts inhibited more than 25% of α-glucosidase activity. C. sinensis displayed an inhibition of 85% (IC50 = 299 μg/mL), while Ludwigia octovalvis and Iostephane heterophylla showed the highest inhibition (82.7 %, IC50 = 202 μg/mL and 60.6%, CI50 = 509 μg/mL, resp.). With respect to lipase activity, L. octovalvis and Tecoma stans were the most inhibiting treatments (31.4%, IC50 = 288 μg/mL; 27.2%, IC50 = 320 μg/mL), while C. sinensis displayed 45% inhibition (IC50 = 310 μg/mL). These results indicate that a high proportion of plants used in Mexico as treatment for diabetes displays significant inhibition of these digestive enzymes. PMID:23082084

  1. Comparisons between conventional, ultrasound-assisted and microwave-assisted methods for extraction of anthraquinones from Heterophyllaea pustulata Hook f. (Rubiaceae).

    PubMed

    Barrera Vázquez, M F; Comini, L R; Martini, R E; Núñez Montoya, S C; Bottini, S; Cabrera, J L

    2014-03-01

    This work reports a comparative study about extraction methods used to obtain anthraquinones (AQs) from stems and leaves of Heterophyllae pustulata Hook (Rubiáceae). One of the conventional procedures used to extract these metabolites from a vegetable matrix is by successive Soxhlet extractions with solvents of increasing polarity: starting with hexane to eliminate chlorophylls and fatty components, following by benzene and finally ethyl acetate. However, this technique shows a low extraction yield of total AQs, and consumes large quantities of solvent and time. Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) have been investigated as alternative methods to extract these compounds, using the same sequence of solvents. It was found that UAE increases the extraction yield of total AQs and reduces the time and amount of solvent used. Nevertheless, the combination UAE with benzene, plus MAE with ethyl acetate at a constant power of 900 W showed the best results. A higher yield of total AQs was obtained in less time and using the same amount of solvent that UAE. The optimal conditions for this latter procedure were UAE with benzene at 50 °C during 60 min, followed by MAE at 900 W during 15 min using ethyl acetate as extraction solvent. PMID:24071561

  2. Eriophyes species (Acari: Eriophyoidea) inhabiting lime trees (Tilia spp.: Tiliaceae)--supplementary description and morphological variability related to host plants and female forms.

    PubMed

    Soika, Grazyna; Kozak, Marcin

    2013-01-01

    Three poorly known species of the subfamily Eriophyinae living on Tilia spp. (Tiliaceae) are illustrated and supplementary descriptions are provided. Two of them, Eriophyes exilis (Nalepa 1892) and Eriophyes nervalis (Nalepa 1918), were recorded both in vein angle galls on leaves of Tilia platyphyllos Scop. and in erinea on leaves of Tilia tomentosa Moench, Tilia americana L. 'Moltkei', Tilia americana var. heterophylla (Vent.) Loudon, Tilia cordata Mill., Tiliajaponica (Miq.) Simonk., Tilia petiolaris DC. and Tilia zamoyskiana Wr6bl. The third species, Eriophyes tiliae Nalepa 1890, was found in nail galls on leaves of T platyphyllos, T americana and T. cordata. All of these Eriophyes species showed noticeable morphological differences between protogyne and deutogyne females in terms of the number of dorsal annuli, location of setae d, length of setae e and 3a, distance between tubercles 3a and the length and pattern of the prodorsal shield. Based on a comparative morphological analysis of this original data with that published by A. Nalepa, new synonyms for the following species are proposed: Erophyes exilis (Nalepa) = Eriophyes leiosoma Nalepa syn. nov.; Eriophyes nervalis (Nalepa) = Eriophyes tiliaceus Nalepa syn. nov., Eriophyes tiliae Nalepa = Eriophyes rudis Nalepa syn. nov. = Eriophyes tomentosae Nalepa syn. nov. A key to all studied Eriophyes species living on lime trees is included. PMID:26213770

  3. Review of potential environmental impacts of transgenic glyphosate-resistant soybean in Brazil.

    PubMed

    Cerdeira, Antonio L; Gazziero, Dionsio L P; Duke, Stephen O; Matallo, Marcus B; Spadotto, Claudio A

    2007-01-01

    Transgenic glyphosate-resistant soybeans (GRS) have been commercialized and grown extensively in the Western Hemisphere, including Brazil. Worldwide, several studies have shown that previous and potential effects of glyphosate on contamination of soil, water, and air are minimal, compared to those caused by the herbicides that they replace when GRS are adopted. In the USA and Argentina, the advent of glyphosate-resistant soybeans resulted in a significant shift to reduced- and no-tillage practices, thereby significantly reducing environmental degradation by agriculture. Similar shifts in tillage practiced with GRS might be expected in Brazil. Transgenes encoding glyphosate resistance in soybeans are highly unlikely to be a risk to wild plant species in Brazil. Soybean is almost completely self-pollinated and is a non-native species in Brazil, without wild relatives, making introgression of transgenes from GRS virtually impossible. Probably the highest agricultural risk in adopting GRS in Brazil is related to weed resistance. Weed species in GRS fields have shifted in Brazil to those that can more successfully withstand glyphosate or to those that avoid the time of its application. These include Chamaesyce hirta (erva-de-Santa-Luzia), Commelina benghalensis (trapoeraba), Spermacoce latifolia (erva-quente), Richardia brasiliensis (poaia-branca), and Ipomoea spp. (corda-de-viola). Four weed species, Conyza bonariensis, Conyza Canadensis (buva), Lolium multiflorum (azevem), and Euphorbia heterophylla (amendoim bravo), have evolved resistance to glyphosate in GRS in Brazil and have great potential to become problems. PMID:17562462

  4. Glyphosate-resistant weeds of South American cropping systems: an overview.

    PubMed

    Vila-Aiub, Martin M; Vidal, Ribas A; Balbi, Maria C; Gundel, Pedro E; Trucco, Frederico; Ghersa, Claudio M

    2008-04-01

    Herbicide resistance is an evolutionary event resulting from intense herbicide selection over genetically diverse weed populations. In South America, orchard, cereal and legume cropping systems show a strong dependence on glyphosate to control weeds. The goal of this report is to review the current knowledge on cases of evolved glyphosate-resistant weeds in South American agriculture. The first reports of glyphosate resistance include populations of highly diverse taxa (Lolium multiflorum Lam., Conyza bonariensis L., C. canadensis L.). In all instances, resistance evolution followed intense glyphosate use in fruit fields of Chile and Brazil. In fruit orchards from Colombia, Parthenium hysterophorus L. has shown the ability to withstand high glyphosate rates. The recent appearance of glyphosate-resistant Sorghum halepense L. and Euphorbia heterophylla L. in glyphosate-resistant soybean fields of Argentina and Brazil, respectively, is of major concern. The evolution of glyphosate resistance has clearly taken place in those agroecosystems where glyphosate exerts a strong and continuous selection pressure on weeds. The massive adoption of no-till practices together with the utilization of glyphosate-resistant soybean crops are factors encouraging increase in glyphosate use. This phenomenon has been more evident in Argentina and Brazil. The exclusive reliance on glyphosate as the main tool for weed management results in agroecosystems biologically more prone to glyphosate resistance evolution. PMID:18161884

  5. Taxonomic significance of trichomes micromorphology in cucurbits

    PubMed Central

    Ali, Mohammad Ajmal; Al-Hemaid, Fahad M.A.

    2010-01-01

    Studies on trichomes micromorphology using Scanning Electron Microscope (SEM) were undertaken in 23 species with one variety under 13 genera of the family Cucurbitaceae (viz., Benincasa hispida (Thunb.) Cogn., Citrullus lanatus (Thunb.) Matsum. & Nakai, Cucumis melo var. agrestis Naudin, Cucumis sativus L., Diplocyclos palmatus (L.) C. Jeffrey, Edgaria dargeelingensis C.B. Clarke, Gynostemma burmanicum King ex Chakr., Gynostemma pentaphyllum (Thunb.) Makino, Gynostemma pubescens (Gagnep.) C.Y. Wu, Hemsleya dipterygia Kuang & A.M. Lu, Lagenaria siceraria (Molina) Standl., Luffa acutangula (L.) Roxb., Luffa cylindrica M. Roem., Luffa echinata Roxb., Melothria heterophylla (Lour.) Cogn., Melothria leucocarpa (Blume) Cogn., Melothria maderspatana (L.) Cogn., Sechium edule (Jacq.) Sw., Thladiantha cordifolia (Blume) Cogn., Trichosanthes cucumerina L., T. cucumerina var. anguina (L.) Haines, Trichosanthes dioica Roxb., Trichosanthes lepiniana (Naudin) Cogn. and T. tricuspidata Lour.). The trichomes in the family Cucurbitaceae vary from unicellular to multicellular, conical to elongated, smooth to ridges, with or without flattened disk at base and cyctolithic appendages, thin to thick walled, curved at apices to blunt. Trichomes micromorphology in the family Cucurbitaceae was found significant taxonomically. PMID:23961108

  6. Delayed tree mortality in the Atchafalaya Basin of Southern Louisiana following Hurricane Andrew

    USGS Publications Warehouse

    Keeland, B.D.; Gorham, L.E.

    2009-01-01

    Hurricanes can damage trees in forested wetlands, and the potential for mortality related to these storms exists due to the effects of tree damage over time. In August 1992, Hurricane Andrew passed through the forested wetlands of southern Louisiana with winds in excess of 225 kph. Although more than 78 of the basal area was destroyed in some areas, most trees greater than 2.5 cm dbh were alive and resprouting prolifically the following year (98.8). Survival of most tree species was similarly high two years after the hurricane, but mortality rates of some species increased dramatically. For example, Populus heterophylla (swamp cottonwood) mortality increased from 7.8 to 59.2 (n 76) and Salix interior (sandbar willow) mortality increased from 4.5 to 57.1 (n 21). Stem sprouts on many up-rooted hardwood trees of other species were still alive in 1998, 6 years after the hurricane. Due to the understory tree species composition, regeneration, and high levels of resprouting, there was little change in species composition or perhaps a slight shift toward more shade and flood tolerant species six years following the hurricane event. Triadica sebifera (Chinese tallow) was found on some of the sites heavily disturbed by Hurricane Andrew, and may proliferate at the expense of native tree species. ?? 2009 The Society of Wetland Scientists.

  7. Using Peatland Archives to Assess Climate Forcing of Holocene Vegetational Changes: Case Studies From the Great Lakes Region

    NASA Astrophysics Data System (ADS)

    Jackson, S. T.; Booth, R. K.; Andersen, J.; Hotchkiss, S.; Huang, Y.; Lesser, M.; Minckley, T.; Nichols, J.; Pendall, E.; Reeves, K.; Taylor, M.

    2006-12-01

    A dilemma has long confronted paleoecologists: pollen data are required to assess past vegetational changes, and at the same time pollen data serve as a primary source of paleoclimate inference. Paleoecologists have had to use the same data sets to infer past climate changes and the ecological responses to those changes. The emergence of independent paleoclimate proxies and archives is providing relief from this dilemma. Peatland archives are especially effective at providing independent paleoclimatic records, owing to their sensitivity to climate variation, their subcentennial to subdecadal temporal precision, and the multiplicity of available proxies. Pollen records can be obtained from the same stratigraphic levels as paleoclimate proxies, and peatland records can also be compared with lake-based pollen and macrofossil records at regional scales. Peatland records of mid- to late Holocene climate change and variability, together with pollen and macrofossil records from peatlands and lakes in the Great Lakes region of North America, resolve some long-standing questions and controversies concerning the causation of vegetational changes in the region. We present three case studies where peatlands have played a pivotal role. 1. Hemlock populations plummeted across eastern North America 5400 yr BP. The extent, rapidity, and synchrony of the event suggested that it resulted from a widespread pathogen outbreak, similar to the early 20th Century chestnut blight in the same region. However, some have argued for climate as a primary mechanism. Paleohydrological records from a kettle bog in northeastern Lower Michigan indicate an abrupt decline in water-table depth 5400 yr BP that persisted for the next 2500 years, coincident with the hemlock decline. Pathogens may have played a proximal role, but an abrupt climate shift was the ultimate driver of the hemlock decline. 2. Holocene expansions of yellow birch and beech in their northwestern ranges were episodic, alternating between rapid expansion and extended quiescence. The extent to which these patterns were governed by climate variations versus migration lag or geographic barriers has remained unclear. Peatland records from the Lake Superior region indicate that the migrations were paced by climate variation. For example, rapid westward expansion of yellow birch occurred during a 1200-yr period of sustained wet conditions, following on the heels of a severe multidecadal drought 4200-4000 yr BP. Widespread forest disturbance during the drought may have facilitated subsequent expansion of yellow birch. Beech expansion also occurred during wet intervals. 3. Beech populations declined and pine increased across the central Great Lakes region 1100 700 yr BP. This has been variously attributed to late Holocene cooling and to widespread fires set by Native Americans. Records from an ombrotrophic peatland in southeastern Lower Michigan reveal that the beech decline was coincident with onset of a series of severe, multidecadal drought events.

  8. Late Holocene environmental change at three glacier-fed lakes, southern Alaska

    NASA Astrophysics Data System (ADS)

    Kaufman, D. S.; Anderson, R. S.; Daigle, T. A.; Kathan, K. M.; McKay, N. P.; Michelutti, N. N.; Werner, A.

    2007-12-01

    Lake-sediment cores and glacial geomorphology were used to infer late Holocene paleoenvironmental changes at three glacier-fed lakes across southern Alaska. The lakes form a 730-km-long transect around 60N lat, and they span the transition zone between two centers of opposite surface air-temperature responses attributed to fluctuations in the strength of the Aleutian Low, the primary indicator of winter climate in the North Pacific. Sediment cores from Hallet Lake in the NE Chugach Range display varying concentrations of biogenic silica (BSi), a measure of overall lake production. A transfer function was developed to infer summer temperature from downcore BSi content. The reconstruction shows clear evidence of first millennium AD cooling, warmth from 1300-1500 AD, Little Ice Age (LIA) cooling between 1750 and 1900 AD, and recent warming beginning ca. 1900 AD. During the last 30 yr, summer temperatures were nearly 2C warmer than the reconstructed mean of the past 2 millennia. Goat Lake is near treeline in the Kenai Mountains, and about 1 km from an outlet glacier of the Harding Icefield. Pollen assemblages show increasing abundances of mountain hemlock from 700-1200 AD, which we interpret as an expansion of treeline. The expansion was terminated around 1230 AD when 10 cm of tephra was deposited in the lake. Treeline above the modern and prior to the LIA is further indicated by a 14C age of 1470 85 AD on logs exposed below till at the present glacier terminus. By 1660 AD the outlet glacier thickened by 150 m where it overtopped its drainage divide and spilled meltwater into Goat Lake, which continued until around 1890 AD. Since then, hemlock pollen has increased to levels comparable to the 1200 AD peak, and the outlet glacier has retreated 1.4 km to the location of the 1470 AD logs. At Cascade Lake, sediment traps installed for 2 yr collected 77% less BSi when spring and summer temperatures were lower, suggesting that BSi flux in the lake is related to growing-season conditions. BSi was at its minimum early during the first millennium AD. It peaked around 700 AD, then decreased during the next 400 yr. BSi flux was relatively constant until the 19th century when it decreased to near-minima values, then attained its highest values of the last 2000 yr late during the 20th century. BSi and hemlock pollen are probably related more strongly to summer conditions than to winter, whereas glaciers respond to a combination of winter and summer climate variability. Late Holocene moraines in the forefields of cirque glaciers around all study lakes were mapped and dated roughly with lichenometry. The moraines delimit maximum glacier positions attained late in the 19th century, when glacier snouts generally descended less than 100 m in elevation relative to their 1950-1970 positions. This limited LIA expansion, together with tree-ring and other independent evidence for decades-long LIA summer cooling of at least 0.8C in south-central Alaska, indicates a reduction in accumulation-season precipitation during the LIA. A simultaneous reduction in winter precipitation across southern Alaska is difficult to ascribe to a shift in the Aleutian Low pressure system because instrumental data show dipolar responses across this region. This implies a longer- term, more general climate forcing that supersedes inter-decadal variability in the Aleutian Low.

  9. Petroleum geology of Cook Inlet basin - an exploration model

    USGS Publications Warehouse

    Magoon, L.B.; Claypool, G.E.

    1981-01-01

    Oil exploration commenced onshore adjacent to lower Cook Inlet on the Iniskin Peninsula in 1900, shifted with considerable success to upper Cook Inlet from 1957 through 1965, then returned to lower Cook Inlet in 1977 with the COST well and Federal OCS sale. Lower Cook Inlet COST No. 1 well, drilled to a total depth of 3,775.6 m, penetrated basinwide unconformities at the tops of Upper Cretaceous, Lower Cretaceous, and Upper Jurassic strata at 797.1, 1,540.8, and 2,112.3 m, respectively. Sandstone of potential reservoir quality is present in the Cretaceous and lower Tertiary rocks. All siltstones and shales analyzed are low (0 to 0.5 wt. %) in oil-prone organic matter, and only coals are high in humic organic matter. At total depth, vitrinite readings reached a maximum ave age reflectance of 0.65. Several indications of hydrocarbons were present. Oil analyses suggest that oils from the major fields of the Cook Inlet region, most of which produce from the Tertiary Hemlock Conglomerate, have a common source. More detailed work on stable carbon isotope ratios and the distribution of gasoline-range and heavy (C12+) hydrocarbons confirms this genetic relation among the major fields. In addition, oils from Jurassic rocks under the Iniskin Peninsula and from the Hemlock Conglomerate at the southwestern tip of the Kenai lowland are members of the same or a very similar oil family. The Middle Jurassic strata of the Iniskin Peninsula are moderately rich in organic carbon (0.5 to 1.5 wt. %) and yield shows of oil and of gas in wells and in surface seeps. Extractable hydrocarbons from this strata are similar in chemi al and isotopic composition to the Cook Inlet oils. Organic matter in Cretaceous and Tertiary rocks is thermally immature in all wells analyzed. Oil reservoirs in the major producing fields are of Tertiary age and unconformably overlie Jurassic rocks; the pre-Tertiary unconformity may be significant in exploration for new oil reserves. The unconformable relation between reservoir rocks and likely Middle Jurassic source rocks also implies a delay in the generation and expulsion of oil from Jurassic until late Tertiary when localized basin subsidence and thick sedimentary fill brought older, deeper rocks to the temperature required for petroleum generation. Reservoir porosities, crude oil properties, the type of oil field traps, and the tectonic framework of the oil fields on the west flank of the basin provide evidence used to reconstruct an oil migration route. The route is inferred to commence deep in the truncated Middle Jur ssic rocks and pass through the porous West Foreland Formation in the McArthur River field area to a stratigraphic trap in the Oligocene Hemlock Conglomerate and the Oligocene part of the Tyonek Formation at the end of Miocene time. Pliocene deformation shut off this route and created localized structural traps, into which the oil moved by secondary migration to form the Middle Ground Shoal, McArthur River, and Trading Bay oil fields. Oil generation continued into the Pliocene, but this higher API gravity oil migrated along a different route to the Granite Point field.

  10. Paleofire reconstruction for high-elevation forests in the Sierra Nevada, California, with implications for wildfire synchrony and climate variability in the late Holocene

    NASA Astrophysics Data System (ADS)

    Hallett, Douglas J.; Anderson, R. Scott

    2010-03-01

    Here, we present two high-resolution records of macroscopic charcoal from high-elevation lake sites in the Sierra Nevada, California, and evaluate the synchroneity of fire response for east- and west-side subalpine forests during the past 9200 yr. Charcoal influx was low between 11,200 and 8000 cal yr BP when vegetation consisted of sparse Pinus-dominated forest and montane chaparral shrubs. High charcoal influx after ˜ 8000 cal yr BP marks the arrival of Tsuga mertensiana and Abies magnifica, and a higher-than-present treeline that persisted into the mid-Holocene. Coeval decreases in fire episode frequency coincide with neoglacial advances and lower treeline in the Sierra Nevada after 3800 cal yr BP. Independent fire response occurs between 9200 and 5000 cal yr BP, and significant synchrony at 100- to 1000-yr timescales emerges between 5000 cal yr BP and the present, especially during the last 2500 yr. Indistinguishable fire-return interval distributions and synchronous fires show that climatic control of fire became increasingly important during the late Holocene. Fires after 1200 cal yr BP are often synchronous and corroborate with inferred droughts. Holocene fire activity in the high Sierra Nevada is driven by changes in climate linked to insolation and appears to be sensitive to the dynamics of the El Niño-Southern Oscillation.

  11. Macrofossil and Leaf Wax Biomarkers Reveal Vegetational and Climate History of Tamarack Pond, Black Rock Forest, Southeastern New York

    NASA Astrophysics Data System (ADS)

    Alt, M.; Peteet, D. M.; Nichols, J. E.

    2014-12-01

    Tamarack Pond (41.39500°N 74.02505°W) is located at an elevation of 1305 ft, within the variable topography (Fig. 3) of Black Rock Forest, a 3830-acre oak (Quercus) dominated forest located in the Hudson Highlands Physiographic Province in southeastern New York State. A 7.2 m core retrieved in 4 m of water with a modified Livingstone piston corer was subsampled at 2 and 4-cm intervals from the base of the core through the early Holocene. The basal date of 16, 200 cal. yr BP on Dryas integrifolia leaves in inorganic clays demonstrates the pond formation in a landscape of sparse tundra with Salix, Daphnia, and craneflies. Subsequent inorganic layers record Dryas, Salix, Alnus, Polytrichum juniperum, Sphagnum, and bryozoan statoblasts. A dramatic shift to 25% organic matter in the pond records Picea needles and the first record of charcoal. Continued increases in LOI in the pond are correlative with the presence of Abies balsamea and Betula papyrifera appears as the boreal forest develops and tundra disappears. A return to colder conditions is suggested with a slight decline in LOI as Betula glandulosa and Larix laricina are present along with the boreal mixture, and a large increase in Daphnia ephippia. A return to warmer conditions ensues with the decline of the boreal conifers and the presence of Tsuga canadensis. Leaf wax data will be presented along with the macrofossil results.

  12. Homogeneous genetic structure and variation in tree architecture of Larix kaempferi along altitudinal gradients on Mt. Fuji.

    PubMed

    Nishimura, Masao; Setoguchi, Hiroaki

    2011-03-01

    Variations in tree architecture and in the genetic structure of Larix kaempferi on Mt. Fuji were surveyed along altitudinal gradients using 11 nSSR loci. In total, 249 individuals from six populations along three trails at altitudes ranging from approximately 1,300 to 2,700 m were investigated. Gradual changes in tree architecture with increasing elevation, from erect trees to flag trees and krummholz mats, were observed in the high-altitude populations (> 2,000 m) on all trails. These findings suggest that tree architecture is correlated with the severe environmental conditions associated with increasing elevation, such as strong winds. In contrast to obvious variations in tree architecture, the genetic diversity of populations along the trails was almost uniform (H (E) = 0.717-0.762) across the altitudinal range. The results of the AMOVA and STRUCTURE analyses, and the analysis for isolation by distance pattern, suggest homogeneous genetic structuring across all populations on Mt. Fuji, while the pairwise F (ST) showed barriers to gene flow between altitudinal populations that were demarcated as high- or low-altitude populations by Abies-Tsuga forest. Although the evergreen coniferous forests on the mountainside may hinder gene flow, this may be explained by the long-distance seed dispersal of the Japanese larch and/or a short population history resulting from eruptions or slush avalanches, although evergreen coniferous forests on the mountainside may hinder gene flow. PMID:20711625

  13. Does canopy position affect wood specific gravity in temperate forest trees?

    PubMed

    Woodcock, D W; Shier, A D

    2003-04-01

    The radial increases in wood specific gravity known in many tree species have been interpreted as providing mechanical support in response to the stresses associated with wind loading. This interpretation leads to the hypothesis that individuals reaching the canopy should (1) be more likely to have radial increases in specific gravity and (2) exhibit greater increases than individuals in the subcanopy. Wood specific gravity was determined for three species of forest trees (Acer rubrum, Fagus grandifolia and Tsuga canadensis) growing in central Massachusetts, USA. Acer rubrum shows radial increases in specific gravity, but these increases are not more pronounced in canopy trees; the other two species show a pattern of radial decreases. The degree of radial increase or decrease is influenced by tree height and diameter. Of the dominant tree species for which we have data, A. rubrum, Betula papyrifera and Pinus strobus show radial increases in specific gravity, whereas F. grandifolia, T. canadensis and Quercus rubra show decreases. The occurrence of radial increases in B. papyrifera and P. strobus, which are often canopy emergents, suggests that it is overall adaptive strategy that is important rather than position (canopy vs. subcanopy) of any individual tree. It is suggested that radial increases in specific gravity are associated with early-successional status or characteristics and decreases with late-successional status or persistence in mature forest. PMID:12646497

  14. A 12,000-year history of vegetation and climate for Cape Cod, Massachusetts

    NASA Astrophysics Data System (ADS)

    Winkler, Marjorie Green

    1985-05-01

    Pollen and charcoal analysis of radiocarbon-dated sediment cores from Duck Pond in the Cape Cod National Seashore provide a continuous 12,000-yr vegetation and climate history of outer Cape Cod. A Picea-Hudsonia parkland and then a Picea-Pinus banksiana-Alnus crispa boreal forest association grew near the site between 12,000 and 10,000 yr B.P. This vegetation was replaced by a northern conifer forest of Pinus strobus-P. banksiana, and, subsequently, by a more mesophytic forest ( Pinus strobus, Tsuga, Quercus, Fagus, Acer, Ulmus, Fraxinus, Ostrya) as the climate became warmer and wetter by 9500 yr B.P. By 9000 yr B.P. a Pinus rigida-Quercus association dominated the landscape. High charcoal frequencies from this and subsequent levels suggest that the pine barrens association developed during a warmer and drier climate that lasted from 9000 to about 5000 yr B.P. Increased percentages of Pinus strobus pollen indicate a return to moister and cooler conditions by about 3500 yr B.P. A doubled sedimentation rate, increased charcoal, and increased herb pollen suggest land disturbance near the pond before European settlement. These results suggest a rapid warming in the northeast in the early Holocene and support a hypothesis of a rapid sea level rise at that time. Comparison of the pollen results from Duck Pond with those from Rogers Lake, Connecticut, illustrates the importance of edaphic factors in determining the disturbance frequency and vegetation history of an area.

  15. Parenchyma cell respiration and survival in secondary xylem: does metabolic activity decline with cell age?

    PubMed

    Spicer, R; Holbrook, N M

    2007-08-01

    Sapwood respiration often declines towards the sapwood/heartwood boundary, but it is not known if parenchyma metabolic activity declines with cell age. We measured sapwood respiration in five temperate species (sapwood age range of 5-64 years) and expressed respiration on a live cell basis by quantifying living parenchyma. We found no effect of parenchyma age on respiration in two conifers (Pinus strobus, Tsuga canadensis), both of which had significant amounts of dead parenchyma in the sapwood. In angiosperms (Acer rubrum, Fraxinus americana, Quercus rubra), both bulk tissue and live cell respiration were reduced by about one-half in the oldest relative to the youngest sapwood, and all sapwood parenchyma remained alive. Conifers and angiosperms had similar bulk tissue respiration despite a smaller proportion of parenchyma in conifers (5% versus 15-25% in angiosperms), such that conifer parenchyma respired at rates about three times those of angiosperms. The fact that 5-year-old parenchyma cells respired at the same rate as 25-year-old cells in conifers suggests that there is no inherent or intrinsic decline in respiration as a result of cellular ageing. In contrast, it is not known whether differences observed in cellular respiration rates of angiosperms are a function of age per se, or whether active regulation of metabolic rate or positional effects (e.g. proximity to resources and/or hormones) could be the cause of reduced respiration in older sapwood. PMID:17617821

  16. Paleoecology of late-glacial terrestrial deposits with in situ conifers from the submerged continental shelf of western canada

    NASA Astrophysics Data System (ADS)

    Lacourse, Terri; Mathewes, Rolf W.; Fedje, Daryl W.

    2003-09-01

    Extensive portions of the continental shelf off the coast of British Columbia were subaerially exposed during Late Wisconsinan deglaciation due to lowering of relative sea level by as much as 150 m. Paleoecological analyses were conducted at two sites on the emergent continental shelf where terrestrial surfaces with in situ conifers are preserved. The woody plant remains confirm that, during the latest period of subaerial exposure, terrestrial vegetation was established on the continental shelf. Microscopic identification of fossil wood, and analyses of pollen and plant macrofossils from the associated paleosols and overlying shallow pond sediments indicate that productive Pinus contorta-dominated communities with abundant Alnus crispa and ferns grew on the shelf adjacent to and on the Queen Charlotte Islands around 12,200 14C yr B.P. Dwarf shrubs including Salix and Empetrum, and herbaceous plants such as Heracleum lanatum and Hippuris vulgaris, were also important components of the shelf vegetation. Near northern Vancouver Island, mixed coniferous forests dominated by Pinus contorta with Picea, Tsuga spp., Alnus spp., and ferns occupied the shelf at 10,500 14C yr B.P.

  17. Ice storm damage and early recovery in an old-growth forest.

    PubMed

    Duguay, S M; Arii, K; Hooper, M; Lechowicz, M J

    2001-01-01

    We quantified the damage caused by a major ice storm to individual trees in two 1-ha permanent plots located at Mont St. Hilaire in southwestern Québec, Canada. The storm, which occurred in January 1998, is the worst on record in eastern North America; glaze ice on the order of 80-100 mm accumulated at our study site. All but 3% of the trees (DBH > or = 10 cm) lost at least some crown branches, and 35% lost more than half their crown. Damage to trees increased in the order: Tsuga canadensis, Betula alleghaniensis, Ostrya virginiana, Acer saccharum, Fagus grandifolia, Quercus rubra, Betula papyrifera, Acer rubrum, Tilia americana, and Fraxinus americana. Only 22% of the saplings and small trees (4 cm < DBH < 10 cm) escaped being broken or pinned to the ground by falling material. Levels of damage generally were greater in an exposed ridge top forest than in a cove protected from wind. By August 1999 only 53% of the trees had new shoots developing from the trunk or broken branches; among the more dominant canopy trees, Fagus grandifolia had the least sprouting and Acer saccharum and Quercus rubra the most. We anticipate and will monitor both significant turnover in the tree community and some shift in composition of the canopy dominants. PMID:11339708

  18. Quantifying the Eocene to Pleistocene topographic evolution of the southwestern Alps, France and Italy

    NASA Astrophysics Data System (ADS)

    Fauquette, Séverine; Bernet, Matthias; Suc, Jean-Pierre; Grosjean, Anne-Sabine; Guillot, Stéphane; van der Beek, Peter; Jourdan, Sébastien; Popescu, Speranta-Maria; Jiménez-Moreno, Gonzalo; Bertini, Adele; Pittet, Bernard; Tricart, Pierre; Dumont, Thierry; Schwartz, Stéphane; Zheng, Zhuo; Roche, Emile; Pavia, Giulio; Gardien, Véronique

    2015-02-01

    We evaluate the topographic evolution of the southwestern Alps using Eocene to Pleistocene pollen data combined with existing sedimentological, petrographic and detrital geo- and thermochronological data. We report 32 new pollen analyses from 10 sites completed by an existing dataset of 83 samples from 14 localities situated across the southwestern Alps, including both the pro- and the retro-foreland basins. The presence of microthermic tree pollen (mainly Abies, Picea) indicates that this part of the mountain belt attained elevations over 1900 m as early as the Oligocene. Inferred rapid surface uplift during the mid-Oligocene coincided with a previously documented brief phase of rapid erosional exhumation, when maximum erosion rates may have reached values of up to 1.5-2 km/Myr. Slower long-term average exhumation rates of ∼0.3 km/Myr since the Late Oligocene helped maintaining the high Alpine topography of the southwestern Alps until today. The relative abundances of meso-microthermic tree pollen (Cathaya, Cedrus and Tsuga) and microthermic tree pollen (Abies, Picea) in the pro- and retro-foreland basin deposits, indicate that the present-day asymmetric topography, with a relatively gentle western flank and steeper eastern flank, was established early in the southwestern Alps, at least since the Early Miocene, and possibly since the Oligocene or Late Eocene. Therefore, the high topography and asymmetric morphology of this part of the Alps has been maintained throughout the past ∼30 Ma.

  19. Late Holocene Environment in the Lower Hudson Valley, New York: Medieval Warming, Little Ice Age, and European Impact

    NASA Astrophysics Data System (ADS)

    Pederson, D. C.; Peteet, D. M.; Kurdyla, D.; Guilderson, T.

    2004-05-01

    Two sediment cores from Piermont Marsh, located in the southern Hudson River Valley, provide a well-dated bi-decadal record of vegetation, climate, land use, and fire frequency. The classic Medieval Warm Period is evident through striking increases in charcoal and Pinus dominance from A.D.800-1350, paralleling records southward along the Atlantic seaboard. Higher inputs of inorganic sediment during this interval suggest increased watershed erosion during drought conditions. Increases in Picea and Tsuga with corresponding decreases in Liquidambar, coupled with increasing organic percentages due to cooler, moister conditions indicate the presence of the Little Ice Age. European impact is manifested by increased weedy plant cover (i.e., Ambrosia, Plantago, and Rumex), decline in arboreal pollen due to land clearance, and increase in inorganic particles to the watershed. Radionuclide dating using Cs-137 and Pb-210 from the southern end of the marsh shows that little disturbance of sediments has occurred, adding validity to the high resolution results and supporting the sedimentation rates obtained using radiocarbon dating. Comparison with other marsh records in the Hudson River estuary shows general agreement in chronology with interesting differences in species changes and sedimentation rates.

  20. Global diversity of the Ganoderma lucidum complex (Ganodermataceae, Polyporales) inferred from morphology and multilocus phylogeny.

    PubMed

    Zhou, Li-Wei; Cao, Yun; Wu, Sheng-Hua; Vlasák, Josef; Li, De-Wei; Li, Meng-Jie; Dai, Yu-Cheng

    2015-06-01

    Species of the Ganoderma lucidum complex are used in many types of health products. However, the taxonomy of this complex has long been chaotic, thus limiting its uses. In the present study, 32 collections of the complex from Asia, Europe and North America were analyzed from both morphological and molecular phylogenetic perspectives. The combined dataset, including an outgroup, comprised 33 ITS, 24 tef1α, 24 rpb1 and 21 rpb2 sequences, of which 19 ITS, 20 tef1α, 20 rpb1 and 17 rpb2 sequences were newly generated. A total of 13 species of the complex were recovered in the multilocus phylogeny. These 13 species were not strongly supported as a single monophyletic lineage, and were further grouped into three lineages that cannot be defined by their geographic distributions. Clade A comprised Ganoderma curtisii, Ganoderma flexipes, Ganoderma lingzhi, Ganoderma multipileum, Ganoderma resinaceum, Ganoderma sessile, Ganoderma sichuanense and Ganoderma tropicum, Clade B comprised G. lucidum, Ganoderma oregonense and Ganoderma tsugae, and Clade C comprised Ganoderma boninense and Ganoderma zonatum. A dichotomous key to the 13 species is provided, and their key morphological characters from context, pores, cuticle cells and basidiospores are presented in a table. The taxonomic positions of these species are briefly discussed. Noteworthy, the epitypification of G. sichuanense is rejected. PMID:25453909

  1. Secondary metabolites from Ganoderma.

    PubMed

    Baby, Sabulal; Johnson, Anil John; Govindan, Balaji

    2015-06-01

    Ganoderma is a genus of medicinal mushrooms. This review deals with secondary metabolites isolated from Ganoderma and their biological significance. Phytochemical studies over the last 40years led to the isolation of 431 secondary metabolites from various Ganoderma species. The major secondary compounds isolated are (a) C30 lanostanes (ganoderic acids), (b) C30 lanostanes (aldehydes, alcohols, esters, glycosides, lactones, ketones), (c) C27 lanostanes (lucidenic acids), (d) C27 lanostanes (alcohols, lactones, esters), (e) C24, C25 lanostanes (f) C30 pentacyclic triterpenes, (g) meroterpenoids, (h) farnesyl hydroquinones (meroterpenoids), (i) C15 sesquiterpenoids, (j) steroids, (k) alkaloids, (l) prenyl hydroquinone (m) benzofurans, (n) benzopyran-4-one derivatives and (o) benzenoid derivatives. Ganoderma lucidum is the species extensively studied for its secondary metabolites and biological activities. Ganoderma applanatum, Ganoderma colossum, Ganoderma sinense, Ganoderma cochlear, Ganoderma tsugae, Ganoderma amboinense, Ganoderma orbiforme, Ganoderma resinaceum, Ganoderma hainanense, Ganoderma concinna, Ganoderma pfeifferi, Ganoderma neo-japonicum, Ganoderma tropicum, Ganoderma australe, Ganoderma carnosum, Ganoderma fornicatum, Ganoderma lipsiense (synonym G. applanatum), Ganoderma mastoporum, Ganoderma theaecolum, Ganoderma boninense, Ganoderma capense and Ganoderma annulare are the other Ganoderma species subjected to phytochemical studies. Further phytochemical studies on Ganoderma could lead to the discovery of hitherto unknown biologically active secondary metabolites. PMID:25975187

  2. Pollen analysis of some mid-Pleistocene interglacial lagoonal sediments from southern Delaware*1

    NASA Astrophysics Data System (ADS)

    Nickmann, Rudy J.; Demarest, James M.

    1982-01-01

    Results of pollen analysis on lagoonal sediments from southern Delaware, dated at 500,000-1,000,000 yr B.P. by amino acid racemization, are presented. Three pollen zones are identified in sediments that were deposited during the final stage of an interglacial cycle. A closed forest of mixed conifer-deciduous trees dominated by Tsuga, Pinus, Fagus, Liquidambar, and Quercus is recorded in the basal zone (Zone I). The inferred climate at this time was temperate and moist. A probable lowering of sea level during the deposition of Zone II exposed large areas in the surrounding estuaries and tidal flats which were colonized by marsh and bog plant taxa. Zone III is characterized by Pinus, Quercus, and Picea pollen. A scrub oak-pine association may have been favored on the coarse sandy soils of the Delmarva Peninsula at this time because of a drop in the local water table. The inferred climate during this interval was colder and probably drier than in Zone I.

  3. Holocene vegetation history and Lake Michigan lake-level fluctuations on the southern shore of the Upper Peninsula of Michigan

    SciTech Connect

    Petty, W.H. )

    1994-06-01

    A 250-cm sediment core with a base radiocarbon date of 7960 yrs BP was collected in June of 1993 from Elbow Lake, Mackinac Co., Michigan. Radiocarbon dates and fossil pollen preserved in lake sediments indicate that changes in vegetation are related to changes in climate and proximity to the Lake Michigan shoreline. Basal radiocarbon dates on sediment cores from a transect of ponds combined with tree-ring cores and GLO surveyor notes of a shipwreck reveal an average late-Holocene rate of regression of 3 feet per year. The pollen record, sediment stratigraphy, and sediment accumulation rates show that this general retreat of the shoreline was punctuated by periodic high stands. Radiocarbon dates of [approximately]6900 yrs BP indicate a high stand of Lake Michigan during the late-Chippewa state of Lake Michigan, prior to the classically recognized Nipissing-I high stand at [approximately]4500 yrs PB. Pollen percentages for Tsuga canadensis and Fagus grandifolia both reach > 1% by 5500 yrs BP, indicating that the northern shore of Lake Michigan provided suitable habitat for colonization by these species. Establishment of F. grandifolia at this time is associated with a rise in water table and is [approximately]2000 years prior to its expansion into the interior of the Upper Peninsula after 3500 yrs BP. A further increase in mesic hardwoods along with T. canadensis to their modern level by 2200 yrs BP is associated with an increase in sediment accumulation rate, indicative of a rising lake level and moister climate.

  4. Does Canopy Position Affect Wood Specific Gravity in Temperate Forest Trees?

    PubMed Central

    WOODCOCK, D. W.; SHIER, A. D.

    2003-01-01

    The radial increases in wood specific gravity known in many tree species have been interpreted as providing mechanical support in response to the stresses associated with wind loading. This interpretation leads to the hypothesis that individuals reaching the canopy should (1) be more likely to have radial increases in specific gravity and (2) exhibit greater increases than individuals in the subcanopy. Wood specific gravity was determined for three species of forest trees (Acer rubrum, Fagus grandifolia and Tsuga canadensis) growing in central Massachusetts, USA. Acer rubrum shows radial increases in specific gravity, but these increases are not more pronounced in canopy trees; the other two species show a pattern of radial decreases. The degree of radial increase or decrease is influenced by tree height and diameter. Of the dominant tree species for which we have data, A. rubrum, Betula papyrifera and Pinus strobus show radial increases in specific gravity, whereas F. grandifolia, T. canadensis and Quercus rubra show decreases. The occurrence of radial increases in B. papyrifera and P. strobus, which are often canopy emergents, suggests that it is overall adaptive strategy that is important rather than position (canopy vs. subcanopy) of any individual tree. It is suggested that radial increases in specific gravity are associated with early‐successional status or characteristics and decreases with late‐successional status or persistence in mature forest. PMID:12646497

  5. Early and Middle Pleistocene vegetation history of the Médoc region, southwest France

    NASA Astrophysics Data System (ADS)

    O'Brien, C. E.; Jones, R. L.

    2003-09-01

    Pleistocene deposits, together with their pollen, plant macrofossil, foraminiferal, dinoflagellate and coleopteran remains, from five sites along the Atlantic coast of the Médoc Peninsula are described and discussed. Sediments making up the Négade Formation are shown to have been laid down under either estuarine or lagoonal conditions when closed Quercus-Pinus-Tsuga canadensis regional woodland existed. Comparison with plant records from The Netherlands indicates that these deposits are most likely attributable to either the Early Pleistocene Bavel Interglacial (marine oxygen isotope stage (MIS) 31), or an interglacial of the Waalian (MIS 37-49) or Tiglian (MIS 63-79). In addition, clays assigned to the Argiles du Gurp sensu stricto, were similarly deposited in either an estuary or lagoon, which subsequently was cut off from the sea. A freshwater lake with vegetation dominated by Azolla filiculoides then developed. This was succeeded by reedswamp and an organic mud (termed Lignite in the corresponding French stratigraphical records) formed. Regional Quercus-Abies woodland was replaced by one with Pinus dominant and Pterocarya a minor component. Comparison with plant records from France and other parts of Europe suggest that the clays and organic mud might be correlated with the Holsteinian (Praclaux) Interglacial (MIS 11c). Copyright

  6. Climate Variability and Human Impacts at Tivoli North Bay, Hudson River, New York

    NASA Astrophysics Data System (ADS)

    Sritrairat, S.; Peteet, D. M.; Griffin, K.; Kurdyla, D.; Guilderson, T.

    2006-12-01

    The investigation of pollen, spores, charcoal, organic carbon content, C/N ratios, and radiometric dating provides a paleoecological study of Tivoli North Bay (42oN, 74oW), lower Hudson River. This freshwater tidal marsh record reveals vegetational changes which reflect local and regional vegetational and climatic shifts. Significant charcoal maxima at the base of the core appear to be parallel to the well-dated 500-yr charcoal maxima in Piermont Marsh downriver, implying a regional climatic impact of the Medieval Warming Interval in the lower Hudson Valley. European settlement is marked by very abrupt shift in vegetation and sediment composition as a result of deforestation, invasive species introduction, and infrastructure construction. Betula became a successful replacement of forest dominants such as Quercus, Pinus, and Tsuga. Weedy species including Ambrosia, Impatiens, Chenopodiaceae and Gramineae expand as human impact increases. Higher sedimentation rate due to higher inorganic input appears to contribute to marsh composition changes as woody taxa such as Salix, Cephalanthus, Fraxinus, and Vitis appear in the wetland in the most recent centuries. Additional radiometric control linking stratigraphy from Tivoli North Bay to other Hudson River wetlands as well as pollen and spore analysis of river and air traps will lead to a better understanding of the Hudson watershed history. Significant extended droughts in the Hudson watershed due to natural variability have major implications for future water availability in this landscape.

  7. Kootenai River White Sturgeon Investigations; White Sturgeon Spawning and Recruitment Evaluation, 2003-2004 Annual Report.

    SciTech Connect

    Rust, Pete; Wakkinen, Virginia

    2005-06-01

    The objective of this research was to determine the environmental requirements for successful spawning and recruitment of the Kootenai River white sturgeon Acipenser transmontanus population. Annual tasks include monitoring and evaluating the various life stages of Kootenai River white sturgeon. Sampling for adult Kootenai River white sturgeon in 2003 began in March and continued through April. Eighty-one adult white sturgeon were captured with 3,576 hours of angling and set-lining effort in the Kootenai River. Discharge from Libby Dam and river stage at Bonners Ferry in 2003 peaked in May and early June. Flows remained above 500 m{sup 3}/s throughout June, decreased rapidly through mid July, and increased back to near 500 m{sup 3}/s after mid July and through mid August. By late August, flows had decreased to below 400 m{sup 3}/s. We monitored the movements of 24 adult sturgeon in Kootenay Lake, British Columbia (BC) and the Kootenai River from March 15, 2003 to August 31, 2003. Some of the fish were radio or sonic tagged in previous years. Twelve adult white sturgeon were moved upstream to the Hemlock Bar reach (rkm 260.0) and released as part of the Set and Jet Program. Transmitters were attached to seven of these fish, and their movements were monitored from the time of release until they moved downstream of Bonners Ferry. Eight additional radio-tagged white sturgeon adults were located in the traditional spawning reach (rkm 228-240) during May and June. Sampling with artificial substrate mats began May 21, 2003 and ended June 30, 2003. We sampled 717 mat d (a mat d is one 24 h set) during white sturgeon spawning. Three white sturgeon eggs were collected near Shortys Island on June 3, 2003, and five eggs were collected from the Hemlock Bar reach on June 5, 2003. Prejuvenile sampling began June 17, 2003 and continued until July 31, 2003. Sampling occurred primarily at Ambush Rock (rkm 244.0) in an attempt to document any recruitment that might have occurred from the Set and Jet Program. Sixteen larval fish were collected, but no prejuvenile white sturgeon were collected. Juvenile white sturgeon sampling started July 14, 2003 and continued through September 18, 2003. A total of 330 h of gillnetting effort captured 238 hatchery white sturgeon and three wild white sturgeon.

  8. Detection of long-term trends in carbon accumulation by forests in Northeastern U. S. and determination of causal factors: Final report

    SciTech Connect

    J. William Munger; Steven C. Wofsy; David R. Foster

    2012-01-31

    The overall project goal was to quantify the trends and variability for Net ecosystem exchange of CO{sub 2}, H{sub 2}O, and energy by northeastern forests, with particular attention to the role of succession, differences in species composition, legacies of past land use, and disturbances. Measurements included flux measurements and observations of biomass accumulation using ecosystem modeling as a framework for data interpretation. Continuation of the long-term record at the Environmental Measurement Site (EMS) Tower was a priority. The final quality-assured CO{sub 2}-flux data now extend through 2010. Data through 2011 are collected but not yet finalized. Biomass observations on the plot array centered on the tower are extended to 2011. Two additional towers in a hemlock stand (HEM) and a younger deciduous stand (LPH) complement the EMS tower by focusing on stands with different species composition or age distribution and disturbance history, but comparable climate and soil type. Over the period since 1993 the forest has added 24.4 Mg-C ha{sup -1} in the living trees. Annual net carbon uptake had been increasing from about 2 Mg-C ha{sup -1}y{sup -1} in the early 1990s to nearly 6 Mg-C ha{sup -1}y{sup -1} by 2008, but declined in 2009-2010. We attribute the increasing carbon uptake to a combination of warmer temperatures, increased photosynthetic efficiency, and increased influence by subcanopy hemlocks that are active in the early spring and late autumn when temperatures are above freezing but the deciduous canopy is bare. Not all of the increased carbon accumulation was found in woody biomass. Results from a study using data to optimize parameters in an ecosystem process model indicate that significant changes in model parameters for photosynthetic capacity and shifts in allocation to slow cycling soil organic matter are necessary for the model to match the observed trends. The emerging working hypothesis is that the pattern of increasing carbon uptake over the early 2000's represents a transient pulse that will eventually end as decomposition of the accumulated carbon catches up.

  9. The Effect of Lidar Point Density on LAI Estimation

    NASA Astrophysics Data System (ADS)

    Cawse-Nicholson, K.; van Aardt, J. A.; Romanczyk, P.; Kelbe, D.; Bandyopadhyay, M.; Yao, W.; Krause, K.; Kampe, T. U.

    2013-12-01

    Leaf Area Index (LAI) is an important measure of forest health, biomass and carbon exchange, and is most commonly defined as the ratio of the leaf area to ground area. LAI is understood over large spatial scales and describes leaf properties over an entire forest, thus airborne imagery is ideal for capturing such data. Spectral metrics such as the normalized difference vegetation index (NDVI) have been used in the past for LAI estimation, but these metrics may saturate for high LAI values. Light detection and ranging (lidar) is an active remote sensing technology that emits light (most often at the wavelength 1064nm) and uses the return time to calculate the distance to intercepted objects. This yields information on three-dimensional structure and shape, which has been shown in recent studies to yield more accurate LAI estimates than NDVI. However, although lidar is a promising alternative for LAI estimation, minimum acquisition parameters (e.g. point density) required for accurate LAI retrieval are not yet well known. The objective of this study was to determine the minimum number of points per square meter that are required to describe the LAI measurements taken in-field. As part of a larger data collect, discrete lidar data were acquired by Kucera International Inc. over the Hemlock-Canadice State Forest, NY, USA in September 2012. The Leica ALS60 obtained point density of 12 points per square meter and effective ground sampling distance (GSD) of 0.15m. Up to three returns with intensities were recorded per pulse. As part of the same experiment, an AccuPAR LP-80 was used to collect LAI estimates at 25 sites on the ground. Sites were spaced approximately 80m apart and nine measurements were made in a grid pattern within a 20 x 20m site. Dominant species include Hemlock, Beech, Sugar Maple and Oak. This study has the benefit of very high-density data, which will enable a detailed map of intra-forest LAI. Understanding LAI at fine scales may be particularly useful in forest inventory applications and tree health evaluations. However, such high-density data is often not available over large areas. In this study we progressively downsampled the high-density discrete lidar data and evaluated the effect on LAI estimation. The AccuPAR data was used as validation and results were compared to existing LAI metrics. This will enable us to determine the minimum point density required for airborne lidar LAI retrieval. Preliminary results show that the data may be substantially thinned to estimate site-level LAI. More detailed results will be presented at the conference.

  10. Vegetation and Water Level Changes for the Northeast U.S. During the "8.2 ka Event"

    NASA Astrophysics Data System (ADS)

    Newby, P. E.; Donnelly, J. P.; Shuman, B.; MacDonald, D.

    2006-12-01

    Cool conditions, known as the "8.2 ka event", occurred between 8400 and 7900 cal yr B.P. in Greenland, Europe and elsewhere in the North Atlantic. The impact of this brief cool interval on local forests is recorded in radiocarbon-dated, high-resolution pollen stratigraphies for New Long Pond (41^{0}50'N, 70^{0}42'W) and Davis Pond (42^{0}30'N, 73^{0}19'W), Massachusetts. The vegetation response to the event is recorded differently for regions with contrasting soil types. At New Long Pond, the sandy outwash derived soils are associated with changes in jack/red, white and pitch pine populations, whereas the dominant changes in vegetation for the clay-rich, proglacial lake derived soils around Davis Pond are among oak, hemlock, and beech. At both sites, pollen evidence for the "8.2 ka event" may be easily overlooked within the more dominant regional pattern for the Northeast, which shows a shift from dry to moist conditions in conjunction with changes from predominantly white pine to oak with more mesic plant taxa between 9000 and 8000 cal yr B.P. At New Long Pond, the "8.2 ka event" is brief, preceded by a low-stand in water-level during the early Holocene and dominated by white pine pollen. After 9000 cal yr B.P., pitch pine with beech, maple, hop/hornbeam, elm and ash pollen indicate a mixed mesophytic forest. A radiocarbon-dated decrease in loss-on-ignition values at 8400 cal yr B.P., likely related to a drawdown in lake level, distinguishes the "8.2 event" and helps highlight subtle shifts in vegetation that favor colder and drier conditions than before the event. Following this brief episode, the pollen data indicate a return to warm and moist conditions until about 5600 years ago. At Davis Pond, increased oak and decreased hemlock pollen abundances, followed by an increase in beech pollen abundance is evident and show what may be the dominant regional pollen signature for the "8.2 ka event" in the Northest. This pattern is also recorded at nearby Berry and North Ponds in western Massachusetts. The appearance of ragweed pollen at both Davis and New Long Pond may indicate perturbations to the vegetation that also relate to the "8.2 ka event".

  11. Millennial scale climate variability of the northeast Pacific Ocean and northwest North America based on radiolaria and pollen

    NASA Astrophysics Data System (ADS)

    Pisias, N. G.; Mix, A. C.; Heusser, L.

    2001-08-01

    Radiolaria and pollen abundances in marine sediment cores from the northeast Pacific are used to reconstruct oceanographic and continental climate change during the past glacial cycle (0-150 kyr). These data allow direct comparison of the climate response of continental and oceanic systems. Detailed δ 18O and AMS- 14C measurements provide a link into global stratigraphic frameworks. Canonical correlation analysis extracts two modes of variation common to both the Radiolaria and pollen records. The first mode of variation correlates an assemblage of Radiolaria associated with coastal upwelling with increased redwood, western hemlock, and alder pollen. This association is consistent with the modern relationship between coastal upwelling, coastal fog and redwood forests. A second canonical mode relates an oceanic fauna now found in highest abundance in the far North Pacific with reduced pine and western hemlock pollen abundance. Comparison of these records to an ice core δ 18O record suggests that at wavelengths >3000 years, warm events in Greenland are correlated to intervals of increased coastal upwelling off Oregon, decreases in importance of very cold North Pacific fauna (suggesting warming), and increases in pollen associated with wetter coastal environments. Radiolarian based sea-surface temperature estimates suggest that the variability of the northeast Pacific on this time scale is about 2°C. Warming in the coastal regions reflects reduced advection of the California Current, but is moderated by increases in cool coastal upwelling. We infer that the response of the northeast Pacific to millennial scale climate changes is related to changes in atmospheric circulation at mid- to high latitudes. Preliminary analysis suggests that oceanic variability off Oregon at wavelengths <3000 years is similar to the Dansgaard-Oeschger cycles of the ice core δ 18O records. This variability is associated with changes in subtropical faunal elements without similar changes in other faunal elements. This finding suggests that, unlike longer-period millennial scale events, the propagation of the shorter wavelength events to the Northeast Pacific is through subtropical or tropical teleconnections.

  12. Spruce Budworm (Lepidoptera: Tortricidae) Oral Secretions I: Biology and Function.

    PubMed

    Eveleigh, Eldon; Silk, Peter; Leclair, Gaëtan; Mayo, Peter; Francis, Brittany; Williams, Martin

    2015-12-01

    The potential roles of the oral secretions (OS) of spruce budworm (SBW; Choristoneura fumiferana Clemens) larvae and factors that may affect the volume of OS disgorged were investigated in the laboratory. Experiments revealed that diet-fed SBW larvae readily disgorge OS when induced ("milked"), with minimal overall cost to their development and eventual pupal weight. Exposure of conspecific larvae to OS throughout larval development negatively affected survival and male pupal weight; however, male development time was faster when exposed to OS. Female pupal weight and development time were not affected. Preliminary experiments suggested that OS had a repellent effect on a co-occurring herbivore, the false hemlock looper, Nepytia canosaria (Walker). OS produced by larvae that fed on three host tree species and on artificial diet significantly increased the grooming time of ants (Camponotus sp.), indicating that SBW OS have an anti-predator function. The volume of OS is significantly greater in L6 than in L4 or L5, with the volume produced by L6 depending on weight and age as well as feeding history at time of milking. These findings indicate that SBW OS function as both an intra- and interspecific epideictic pheromone and as an anti-predator defensive mechanism, while incurring minimal metabolic costs. PMID:26454475

  13. Habitat requirements of the endangered California freshwater shrimp (Syncaris pacifica) in lagunitas and olema creeks, Marin County, California, USA

    USGS Publications Warehouse

    Martin, B.A.; Saiki, M.K.; Fong, D.

    2009-01-01

    This study was conducted to better understand the habitat requirements and environmental limiting factors of Syncaris pacifica, the California freshwater shrimp. This federally listed endangered species is native to perennial lowland streams in a few watersheds in northern California. Field sampling occurred in Lagunitas and Olema creeks at seasonal intervals from February 2003 to November 2004. Ten glides, five pools, and five riffles served as fixed sampling reaches, with eight glides, four pools, and four riffles located in Lagunitas Creek and the remainder in Olema Creek. A total of 1773 S. pacifica was counted during this study, all of which were captured along vegetated banks in Lagunitas Creek. Syncaris pacifica was most numerous in glides (64), then in pools (31), and lastly in riffles (5). According to logistic regression analysis, S. pacifica was mostly associated with submerged portions of streambank vegetation (especially overhanging vegetation such as ferns and blackberries, emergent vegetation such as sedge and brooklime, and fine roots associated with water hemlock, willow, sedge, and blackberries) along with low water current velocity and a sandy substrate. These seemingly favorable habitat conditions for S. pacifica were present in glides and pools in Lagunitas Creek, but not in Olema Creek. ?? 2009 The Crustacean Society.

  14. Silicon production process evaluations

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Chemical engineering analysis was continued for the HSC process (Hemlock Semiconductor Corporation) in which solar cell silicon is produced in a 1,000 MT/yr plant. Progress and status are reported for the primary engineering activities involved in the preliminary process engineering design of the plant base case conditions (96%), reaction chemistry (96%), process flow diagram (85%), material balance (85%), energy balance (60%), property data (60%), equipment design (40%), major equipment list (30%) and labor requirements (10%). Engineering design of the second distillation column (D-02, TCS column) in the process was completed. The design is based on a 97% recovery of the light key (TCS, trichlorosilane) in the distillate and a 97% recovery of the heavy key (TET, silicon tetrachloride) in the bottoms. At a reflux ratio of 2, the specified recovery of TCS and TET is achieved with 20 trays (equilibrium stages, N=20). Respective feed tray locations are 9, 12 and 15 (NF sub 1 = 9, NF sub 2 = 12,, and NF sub 3 = 15). A total condenser is used for the distillation which is conducted at a pressure of 90 psia.

  15. Aerospace Toxicology and Microbiology

    NASA Technical Reports Server (NTRS)

    James, John T.; Parmet, A. J.; Pierson, Duane L.

    2007-01-01

    Toxicology dates to the very earliest history of humanity with various poisons and venom being recognized as a method of hunting or waging war with the earliest documentation in the Evers papyrus (circa 1500 BCE). The Greeks identified specific poisons such as hemlock, a method of state execution, and the Greek word toxos (arrow) became the root of our modern science. The first scientific approach to the understanding of poisons and toxicology was the work during the late middle ages of Paracelsus. He formulated what were then revolutionary views that a specific toxic agent or "toxicon" caused specific dose-related effects. His principles have established the basis of modern pharmacology and toxicology. In 1700, Bernardo Ramazzini published the book De Morbis Artificum Diatriba (The Diseases of Workers) describing specific illnesses associated with certain labor, particularly metal workers exposed to mercury, lead, arsenic, and rock dust. Modern toxicology dates from development of the modern industrial chemical processes, the earliest involving an analytical method for arsenic by Marsh in 1836. Industrial organic chemicals were synthesized in the late 1800 s along with anesthetics and disinfectants. In 1908, Hamilton began the long study of occupational toxicology issues, and by WW I the scientific use of toxicants saw Haber creating war gases and defining time-dosage relationships that are used even today.

  16. Effects of introduced insects and diseases on forest ecosystems in the Catskill Mountains of New York.

    PubMed

    Lovett, Gary M; Arthur, Mary A; Weathers, Kathleen C; Griffin, Jacob M

    2013-09-01

    Repeated invasions of non-native insects and pathogens have altered the structure and function of forest ecosystems in the Catskill Mountains of New York State, and will continue to do so in the future. Gypsy moth, beech bark disease, and hemlock woolly adelgid are among the insects and diseases currently established in the Catskills that are having significant effects on forests. Many others, including emerald ash borer, Asian long-horned beetle, Phytophthora ramorum, and Sirex wood wasp, are either very recently established in the Catskills or have been found elsewhere in North America and threaten to spread to this region. Short-term disturbances associated with these pests include reduction of productivity, tree decline and mortality, disruption of nutrient cycles, and reduction of seed production. Longer-term impacts are associated with shifts in tree species composition that alter productivity, nutrient cycling, and biodiversity. Catskill forests at mid to high elevations, such as the New York State Forest Preserve lands, are dominated by sugar maple and are particularly vulnerable to pests that use maple as a host, including the Asian long-horned beetle. The simultaneous effects of multiple invading insects and pathogens, and their interactions with changing climate and air pollution regimes, make it very difficult to predict the future composition of Catskill forests. PMID:23844706

  17. Holocene precipitation in the coastal temperate rainforest complex of southern British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Brown, K. J.; Fitton, R. J.; Schoups, G.; Allen, G. B.; Wahl, K. A.; Hebda, R. J.

    2006-11-01

    Pollen data from 69 surface samples from Vancouver Island, Canada, were used to develop a ratio index of precipitation, Douglas fir-western hemlock index (DWHI). DWHI ratios were combined with interpolated estimates of mean annual precipitation to develop pollen-based precipitation transfer functions. The optimal regression model, with a predictive range of 960-2600 mm, was applied to 10 Holocene lake sediment records distributed across a ˜150 km long coastal-inland precipitation gradient. Predicted precipitation was spatially modelled in a geographic information system to examine the spatio-temporal history of precipitation from this representative portion of the coastal temperate rainforest (CTR) complex of western North America. The reconstructions show widespread early Holocene dry conditions coupled with a steep east-west precipitation gradient. Thereafter, the modern precipitation gradient established 7000 years ago, illustrating that the CTR complex has experienced marked short-distance east-west changes in precipitation in the past. Changes in the abundance of arboreal and non-arboreal vegetation, as well as fire disturbance, are often concomitant with changes in Holocene precipitation. Given the precipitation and vegetation history of the region, conservation initiatives should focus on the moist outer coastal zone since it appears to have the greatest amount of resilience to perturbations in precipitation, whereas monitoring programs for signs of climate change should be initiated in central and eastern areas as they appear sensitive to changes in the moisture regime.

  18. Holocene Precipitation in the Coastal Temperate Rainforest Complex of Western North America

    NASA Astrophysics Data System (ADS)

    Brown, K. J.; Fitton, R. J.; Schoups, G.; Allen, G. B.; Wahl, K. A.; Hebda, R. J.

    2006-12-01

    Pollen data from 69 surface samples from Vancouver Island, Canada, were used to develop a ratio index of precipitation, DWHI (Douglas fir-western hemlock index). DWHI ratios were combined with interpolated estimates of mean annual precipitation to develop pollen-based precipitation transfer functions. The optimal regression model, with a predictive range of 960-2600 mm, was applied to 10 Holocene lake sediment records distributed across a ~150 km long coastal-inland precipitation gradient. Predicted precipitation was spatially modelled in a geographic information system to examine the spatio-temporal history of precipitation from this representative portion of the coastal temperate rainforest (CTR) complex of western North America. The reconstructions show widespread early Holocene dry conditions coupled with a steep east-west precipitation gradient. Thereafter, the modern precipitation gradient established 7000 years ago, illustrating that the CTR complex has experienced marked short-distance east-west changes in precipitation in the past. Changes in the abundance of arboreal and non-arboreal vegetation, as well as fire disturbance, are often concomitant with changes in Holocene precipitation. Given the precipitation and vegetation history of the region, conservation initiatives should focus on the moist outer coastal zone since it appears to have the greatest amount of resilience to perturbations in precipitation, whereas monitoring programs for signs of climate change should be initiated in central areas as they appear sensitive to changes in the moisture regime.

  19. Practical toxicologic diagnosis.

    PubMed

    Mount, M E; Feldman, B F

    1984-08-01

    Strychnine toxicosis is characterized by inducible tetanic seizures and metaldehyde poisoning by fine fasciculations progressing to generalized tremors and seizures. Intoxication with 1080 causes seizures, random running movements, vomiting, defecation, urination, acidosis and hyperglycemia. Intoxication with rodenticides causing coagulopathy is characterized by hemorrhage into body cavities but not necessarily external hemorrhage. Anticholinesterase insecticides cause salivation, urination and defecation, while chlorinated hydrocarbon insecticides cause CNS disturbances. Ethylene glycol intoxication results in ataxia, depression, coma, vomiting and tachypnea, followed by acute renal failure. Urea poisoning causes bloat and CNS signs in cattle. Monensin intoxication in horses lasts several days and causes stiffness, colic, uneasiness and recumbency. Salt poisoning results in depression, seizures and hypernatremia. Lead poisoning is associated with central and peripheral nervous system signs, as well as increased numbers of nucleated RBC and basophilic stippling of RBC. Arsenic poisoning results in GI pain, diarrhea, weakness and death. Copper toxicosis in sheep is manifested by hemolytic anemia, hemoglobinemia and hemoglobinuria. Plants that may intoxicate domestic animals include sorghum, greasewood, halogeton, water hemlock, Japanese yew, larkspur, lupine, milk-weed, philodendron, oleander, castor bean and precatory bean. PMID:6493203

  20. Glacial geology, glacial recession, proglacial lakes, and postglacial environments, Fishers Island, New York

    SciTech Connect

    Sirkin, L. ); Funk, R.E. . Anthropological Survey)

    1993-03-01

    The Fishers Island Moraine, a complex of three parallel ice margin depositional trends, forms the west-central segment of a major recessional moraine of the Connecticut-Rhode Island Lobe of the late Wisconsinan glacier. As such, the moraine links the Orient Point Moraine of eastern Long Island and the Charlestown Moraine of western Rhode Island and marks a prominent recessional ice margin. The moraine is correlative with the Roanoke Point Moraine of the Connecticut Lobe of northeastern Long Island. Pollen stratigraphy of >13,180 ka bog sediments begins early in the spruce (A) pollen zone with evidence of a cold, late-glacial climate. The pine (B) pollen zone, beginning prior to 11,145 ka, and the oak (C) pollen zone, dating from about 9,000 ka with hickory and hemlock subzones, are well represented. However, after about 2,000 ka, the stratigraphic record in the bog sections is missing in most cases due to peat harvesting. Pollen spectra from several archeological sites fall within the late oak pollen zone, well within the land clearing interval with evidence of hardwood forests and locally holly and cedar. Evidence of cultigens in the pollen record is sparse. Marine deposits over fresh water bog and proglacial lake sediments show that some coastal bogs were drowned by sea level rise.

  1. Insect succession on buried carrion in two biogeoclimatic zones of British Columbia.

    PubMed

    VanLaerhoven, S L; Anderson, G S

    1999-01-01

    We established a database of insect succession on buried carrion in two biogeoclimatic zones of British Columbia over a 16-month period beginning June 1995. Pig (Sus scrofa L.) carcasses were buried shortly after death in the Coastal Western Hemlock and Sub-boreal Spruce biogeoclimatic zones of British Columbia. Buried pigs exhibited a distinct pattern of succession from that which occurred on above-ground carrion. The species composition and time of colonization for particular species differed between the two zones. Therefore ideally, a database of insect succession on buried carrion should be established for each major biogeoclimatic zone. We did not observe maggot masses on any of the buried carcasses; therefore, the presence of maggot masses may indicate a delayed burial. Soil temperature was a better indicator of internal buried carcass temperature (r2 = 0.92, p < 0.0001) than was ambient air temperature (r2 = 0.60, p < 0.0001); thus soil temperature should be used to determine developmental rates of insects for determination of the postmortem interval by a forensic entomologist. PMID:9987868

  2. Measurement of biogenic hydrocarbon emissions from vegetation in the Lower Fraser Valley, British Columbia

    NASA Astrophysics Data System (ADS)

    Drewitt, G. B.; Curren, K.; Steyn, D. G.; Gillespie, T. J.; Niki, H.

    Biogenic volatile organic compounds (VOCs) participate in many chemical reactions in the atmosphere and in some cases, adversely affect air quality through increased production of photochemical ozone near urban sources of nitrogen oxides. In order to implement an effective control strategy, the relative role of these biogenic hydrocarbon emissions in producing ground-level ozone must be known. During the summers of 1995 and 1996, a field study was undertaken to determine fluxes of biogenic VOCs from both natural and agricultural surfaces in the Lower Fraser Valley located in southwestern British Columbia. Emissions from agricultural surfaces were measured using a flux gradient approach while emissions from the dominant tree species in the region were measured with a branch enclosure system. Results show very little biogenic VOC production from many agricultural crops such as pasture, Potatoes or Blueberries. Cranberries showed very high emissions during the summer of 1994 but failed to show similar results during the summer of 1995. Emissions of isoprene and monoterpenes from native tree species such as Western Red Cedar, Douglas Fir and Coastal Hemlock were quite low. Cottonwood trees on the other hand had fairly low emissions of monoterpenes but extremely high emissions of isoprene. Measurements provided here will be useful for improving our database of hydrocarbon emissions rates from vegetation for future emission inventories and model testing.

  3. An appraisal of the classic forest succession paradigm with the shade tolerance index.

    PubMed

    Lienard, Jean; Florescu, Ionut; Strigul, Nikolay

    2015-01-01

    In this paper we revisit the classic theory of forest succession that relates shade tolerance and species replacement and assess its validity to understand patch-mosaic patterns of forested ecosystems of the USA. We introduce a macroscopic parameter called the "shade tolerance index" and compare it to the classic continuum index in southern Wisconsin forests. We exemplify shade tolerance driven succession in White Pine-Eastern Hemlock forests using computer simulations and analyzing approximated chronosequence data from the USDA FIA forest inventory. We describe this parameter across the last 50 years in the ecoregions of mainland USA, and demonstrate that it does not correlate with the usual macroscopic characteristics of stand age, biomass, basal area, and biodiversity measures. We characterize the dynamics of shade tolerance index using transition matrices and delimit geographical areas based on the relevance of shade tolerance to explain forest succession. We conclude that shade tolerance driven succession is linked to climatic variables and can be considered as a primary driving factor of forest dynamics mostly in central-north and northeastern areas in the USA. Overall, the shade tolerance index constitutes a new quantitative approach that can be used to understand and predict succession of forested ecosystems and biogeographic patterns. PMID:25658092

  4. Biomass, net primary production and successional dynamics of a virgin white pine (Pinus strobus) stand in northern Michigan

    SciTech Connect

    Rose, W.M.

    1985-01-01

    Eastern white pine (Pinus strobus L.), averaging 177 years in age, dominates the forests at Hartwick Pines State Park, Michigan, with a basal area of 48.4 m/sup 2//ha, 66.7% of the total. Its mean diameter and height were 58 cm and 36 m, respectively. Hartwick's total biomass, 681 mt/ha, and basal area, 72.6 m/sup 2//ha, are among the highest worldwide. However, total net primary production of trees was a relatively low 7.5 mt/ha/yr. Diameter and height distributions suggest that red maple, sugar maple and beech are succeeding white pipe. Seeding survivorship was greater in the gaps than under the canopy and greater during winter than summer. Sugar maple had the highest overall annual survival rate and red maple had the lowest. Deer browsing may retard succession. There was a significant increase in height and crown cover of unbrowsed maple seedlings because shoot length had not been reduced by browsing. Fewer white pine survived in unbrowsed areas. It was concluded that a possible successional series for this area, if uninterrupted by fire or other disturbance, would be: jack pine for the first 80 years, white pine for 170 years, white pine-northern hardwood for 200 years, hemlock-northern hardwoods for 200 years with maple dominated hardwoods following as a long term stable community. It is hypothesized that biomass would increase to a maximum when white pine dominated and then decrease when hardwoods assumed dominance.

  5. Prevalence of meningeal worm (Parelaphostrongylus tenuis) in white-tailed deer from New Hampshire.

    PubMed

    Thurston, D R; Strout, R G

    1978-01-01

    Parelaphostrongylus tenuis was found in 79 (62.2%) of 127 white-tailed deer heads (Odocoileus virginianus) collected in New Hampshire. Prevalence of infection was higher in fawns and male deer, but older female deer (5.0 + years) had a higher intensity of infection (3.1) than any other age or sex class. Male deer in forest cover type 2 (northern hardwoods-hemlock-white pine) had a significantly greater prevalence of infection than the females in the same habitat (P less than .05). Adult females had a higher prevalence of infection (67.0%) than female fawns (20%) in forest cover type 1 (spruce-fir-northern hardwoods). In the craniums examined, P. tenuis was found most frequently in the tentorium cerebelli (23.6%) while the falx cerebri, the most prevalent site of infection in fawns, was a significantly less frequent site of infection in older deer (P less than .02). Male deer of age class 3.5 years had a significantly higher rate of infection in the dura mater-olfactory lobe than any other age or sex group (P less than .02). The cavernous sinus was the most frequent site of parasitism in male fawns (25.0%) and was the second most common location in all deer (13.4%). PMID:633521

  6. Holocene Lake-Effect Precipitation in Northern Michigan

    NASA Astrophysics Data System (ADS)

    Delcourt, Paul A.; Nester, Peter L.; Delcourt, Hazel R.; Mora, Claudia I.; Orvis, Kenneth H.

    2002-03-01

    Holocene sediments from Nelson Lake, on Michigan's eastern Upper Peninsula, provide isotopic, pollen, and charcoal evidence for a two-step sequence of changes in moisture source and increased lake-effect precipitation during the late Holocene. Between 8000 and 5300 cal yr B.P., a warm, dry climate and zonal atmospheric circulation produced enriched stable oxygen and carbon isotopic values in combination with high percentages of pine pollen and sustained influx of charcoal particles. After 5300 cal yr B.P., decreasing isotopic values in marl and increasing pollen percentages of mesic hardwoods and northern white cedar indicate increased meridional air flow and precipitation from cold winter storms generated in Alberta, Canada. After 3000 cal yr B.P., abrupt declines in values of δ13C and δ18O and increased pollen representation of hemlock, American beech, spruce, and aquatic plants indicate paludification from increased lake-effect snowfall. The moisture was derived from the Great Lakes and transported by Alberta cyclonic storms that were steered across Lakes Superior and Michigan by a southward shift in the modal winter position of the polar jet stream.

  7. Chemical characterization of fine particle emissions from fireplace combustion of woods grown in the northeastern United States.

    PubMed

    Fine, P M; Cass, G R; Simoneit, B R

    2001-07-01

    A series of source tests was conducted to determine the chemical composition of fine particle emissions from the fireplace combustion of six species of woods grown in the northeastern United States: red maple, northern red oak, paper birch, eastern white pine, eastern hemlock, and balsam fir. Results include fine particle emission rates for total mass, organic and elemental carbon, ionic species, elemental species including potassium, and over 250 specific organic compounds. The data are intended for use in source-apportionment studies that utilize particulate organic compounds as source-specific tracers. The cellulose pyrolysis product levoglucosan was quantified in each of the wood smokes studied and is thus a good candidate as a molecular tracer for wood combustion in general. Differences in emission rates of specific substituted phenols and resin acids can be used to distinguish between the smoke produced when burning hardwoods versus softwoods. Certain organic compounds, such as betulin from paper birch combustion and juvabione and dehydrojuvabione from balsam fir combustion, are unique to those species and can potentially be utilized to trace particulate emissions back to a specific geographical region where those individual tree species are used for firewood. PMID:11452590

  8. Understanding oxygen isotope environmental signals in tree ring sequences from New York State

    NASA Astrophysics Data System (ADS)

    Anderson, W. W.; Kirby, M. E.; Griggs, C.; Patterson, W. P.; Brasseur, J. M.; Mullins, H. T.; Burnett, A. W.

    2008-12-01

    The development of proxy climate records and analyses that allow for investigation and comparison of widespread regions will enhance the global understanding of past climate change through better correlations of significant events among different locations. Trees with a global distribution ranging from the tropics to the subarctic are an ideal medium from which to develop high-resolution isotopic records equivalent to those from varved lake sequences. However, in order to interpret the isotope record in the tree rings, proper calibration sites must be selected and studied. Here we present the results of a constructed calibration data set of oxygen isotopes in tree rings (1942 to 2003 A.D.) from four different locations, ranging from western, south central, central and southeastern New York State. Species studied for this project include eastern hemlock, eastern white pine, white spruce and tuliptree. The data set indicates that there is a clear regional signal in the oxygen isotope data, which indicates different precipitation sources areas for the four sites; these data have a total range of 25 to 33 V-SMOW. It is anticipated that this calibration data set will be used to calibrate older time-series spanning the Holocene from NE USA.

  9. Groundwater-discharge wetlands in the Tanana Flats, interior Alaska. Study report

    SciTech Connect

    Racine, C.H.; Walters, J.C.

    1991-07-01

    In the northwest corner of the Tanana Flats, a lowland basin just south of Fairbanks in interior Alaska, there is a vast network of floating-mat wetlands or fens that appears to be unique in terms of their origin, large areal extent, and absence of sphagnum moss and associated peat. During the summers of 1989 and 1990 a study of the impacts of airboats on these wetlands included aerial and ground reconnaissance of 20 sites to characterize the vegetation, hydrology and subsurface conditions. These wetlands consist of a floating vegetation mat up to 1 m thick, forming an almost complete cover over deeper water bodies. The mats consist of a tall, dense and productive network of emergent vascular plants, including buckbean (menyanthes trifoliata), swamp horsetail(Equisetum fluviatile), sedges (Carexaquatilis), marshfivefinger(potentilla palustris),water hemlock (Cicuta mackenzieana) and bladderwort (Utricularia sp.). Evidence that these wetlands are formed by groundwater discharge includes (a) the apparent absence of permafrost under these wetlands but its presence on the adjacent forested uplands, (b) nearby winter icings resulting from artesian springs, (c) the relatively high pH, conductivity, calcium and magnesium concentrations of the water, (d) the vascular plant species composition and in particular the absence of Sphagnum moss, and (e) the flow of water and the geological history of the area. Expansion of these fens in several places is suggested by dead and dying white birch along the upland-fen margin, were permafrost thaw and subsidence (thermokarst) is taking place.

  10. Changes in winter conditions impact forest management in north temperate forests.

    PubMed

    Rittenhouse, Chadwick D; Rissman, Adena R

    2015-02-01

    Climate change may impact forest management activities with important implications for forest ecosystems. However, most climate change research on forests has focused on climate-driven shifts in species ranges, forest carbon, and hydrology. To examine how climate change may alter timber harvesting and forest operations in north temperate forests, we asked: 1) How have winter conditions changed over the past 60 years? 2) Have changes in winter weather altered timber harvest patterns on public forestlands? 3) What are the implications of changes in winter weather conditions for timber harvest operations in the context of the economic, ecological, and social goals of forest management? Using meteorological information from Climate Data Online and Autoregressive Integrated Moving Average (ARIMA) models we document substantial changes in winter conditions in Wisconsin, including a two- to three-week shortening of frozen ground conditions from 1948 to 2012. Increases in minimum and mean soil temperatures were spatially heterogeneous. Analysis of timber harvest records identified a shift toward greater harvest of jack pine and red pine and less harvest of aspen, black spruce, hemlock, red maple, and white spruce in years with less frozen ground or snow duration. Interviews suggested that frozen ground is a mediating condition that enables low-impact timber harvesting. Climate change may alter frozen ground conditions with complex implications for forest management. PMID:25463581

  11. Simultaneous prediction of density and moisture content of wood by terahertz time domain spectroscopy

    NASA Astrophysics Data System (ADS)

    Inagaki, Tetsuya; Ahmed, Belal; Hartley, Ian D.; Tsuchikawa, Satoru; Reid, Matthew

    2014-11-01

    In this study, demonstration of simultaneous prediction of solid wood density and moisture content, both of which are critical in manufacturing operations, of 4 species (Aspen, Birch, Hemlock and Maple) was accomplished using terahertz time-domain spectroscopy (THz-TDS). THz measurements of wood at various moisture contents were taken for two orientations of the THz field (parallel and perpendicular) with respect to the visible grain. The real and imaginary parts of the dielectric function averaged over the frequency range of 0.1 to 0.2 THz had strong correlation with density and moisture content of the wood. We extend a model that has been applied previously to oven-dry wood to include the effects of moisture below the fiber saturation point by combining two effective medium models, which allows the dielectric function of water, air and oven-dry cell wall material to be modeled to give an effective dielectric function for the wood. A strong correlation between measured and predicted values for density and moisture content were observed.

  12. A novel circumpolar map for upscaling of carbon fluxes and pools

    NASA Astrophysics Data System (ADS)

    Widhalm, Barbara; Bartsch, Annett; Heim, Birgit; Sabel, Daniel

    2015-04-01

    A circumpolar representative and consistent wetland map is required for a range of applications spanning from upscaling of carbon fluxes and pools to climate modeling and wildlife habitat assessments. Currently available datasets lack sufficient accuracy in many regions of the Arctic. Synthetic Aperture Radar data from satellites have already been shown to be suitable for wetland mapping. ENVISAT Advanced SAR (ASAR) provides global medium resolution data, which in this study is examined with particular focus on wetness patterns. A novel wetness level classification has been developed using ASAR backscatter statistics within the framework of PAGE21 (www.page21.eu). The wetness level product distinguishes between three wetness classes 'wet', 'medium' and 'dry' and a class 'other' which mostly covers flat sandy soils. The comparison with conventional vegetation maps, such as the Circumpolar Arctic Vegetation Map, Northern Land Cover of Canada-Circa 2000, the (USGS) vegetation map of Alaska, GBFM Siberia and the thematic map of wetlands throughout Alaska showed promising results. For instance the comparison with the (USGS) vegetation map of Alaska showed that the class of 'wet sedge tundra' consisted of over 60% wet class pixels and only less than 10% dry pixels, while the non-wet class of 'closed spruce & hemlock forest' showed over 80% dry class pixels and less than 10% wet pixels. This novel map may be utilized for wetland related circumpolar land-atmosphere exchange studies.

  13. Pollen analysis of a late pliocene and early pleistocene section from the Gubik Formation of Arctic Alaska

    USGS Publications Warehouse

    Nelson, R.E.; Carter, L.D.

    1985-01-01

    A 14-m-thick section of marine and nonmarine sediments of the Gubik Formation of northern Alaska, exposed in bluffs near Ocean Point on the Colville River, has been studied by means of pollen analysis. Pollen from the marine sediments, of probable late Pliocene age, records a boreal forest of spruce and birch with minor amounts of alder in the adjacent terrestrial vegetation. Pine and perhaps true fir were probably at or near their northern limit here, but hemlocks and hardwoods were absent. The suggested environment for the Arctic Slope during the time represented by the marine sediments is similar to that of present-day Anchorage. Pollen floras from the overlying fluvial strata, of early or middle Pleistocene age, record predominantly herbaceous taxa indicating tundra conditions probably more severe than those of the present day. These deposits were most likely contemporaneous with glacial conditions in the Brooks Range to the south. Pollen of woody taxa (spruce, alder, birch, heaths) is rare through most of the section, although birch and alder percentages similar to those found in modern river sediments indicate an interstadial or interglacial warming in midsection. Inland climates during glacial episodes may have been similar to those of the present Arctic coast. ?? 1985.

  14. Vegetation and disturbance history of two forest stands in northern New York using paleoecological data from small forest hollows

    SciTech Connect

    Kearsley, J.B.; Jackson, S.T.

    1995-06-01

    Pollen, macrofossils and charcoal from two small hollows (<0.05 ha) were analyzed to reconstruct the vegetational history of an outwash plain in the central Adirondack upland of New York. The basins are located 700 meters apart in contrasting modern vegetation at 461 in elevation. Dave`s Lost Hollow (DLH) is in a hemlock-dominated old-growth forest with yellow birch, red spruce and red maple, and Valhalla Hollow (VH) is surrounded by second-growth forest of white pine, balsam fir, paper birch and red maple. The record from DLH spans the entire Holocene, while VH provides data for the late Holocene. Modem pollen-vegetation data from 26 closed-canopy sites in the area provide evidence for the fine-scale sensing properties of closed- canopy pollen assemblages. We found abundant jack pine needles during the early Holocene at DLH. In contrast, data from the High Peaks, 30 km to the east, show white pine as the dominant pine species during that time period. DLH provides an early Holocene record for yellow birch in the region, whereas yellow birch was not present in the High Peaks until 6,000 yrs. B.P.

  15. Cytochemical localization of cellulases in decayed and nondecayed wood

    SciTech Connect

    Murmanis, L.; Highley, T.L.; Palmer, J.G.

    1987-01-01

    Sawdust from undecayed western hemlock wood and from wood previously decayed by the brown-rot fungus Poria placenta or by the white-rot fungus Ganoderma applanatum was incubated with commercial cellulase from Trichoderma viride. Samples were treated cytochemically to locate cellulase activity and examined by TEM. Results showed that cellulase degraded undecayed wood extensively, with the attack starting on the outer border of a cell wall and progressing inside. Wood decayed by P. placenta, with or without cellulase incubation, and treated by the cytochemical test showed uniform distribution of electron dense particles throughout the cell walls. In wood decayed by G. applanatum, cellulase degradation was similar to that in undecayed wood. From measurements of particle diameter it is suggested that electron dense particles are cellulase. It is concluded that brown-rot and white-rot fungi have different effects on the microstructure of wood. The brown-rot fungus appears to open the wood microstructure so that cellulase can diffuse throughout the degraded tracheid wall.

  16. Natural forests of Maryland: an explanaton of the vegetation map of Maryland

    SciTech Connect

    Brush, G.S.; Lenk, C.; Smith, J.

    1980-03-01

    The forests of Maryland have been mapped at a scale of 1:250,000 on the basis of 15 regional associations: (1) tamarack, (2) bald cypress, (3) hemlock-yellow birch-black birch, (4) river birch-sycamore, (5) sycamore-green ash-box elder-silver maple, (6) shingle oak, (7) chestnut oak-post oak-blackjack oak, (8) chestnut oak-bear oak, (9) chestnut oak, (10) loblolly pine, (11) basket oak-lobolly pine, (12) willow oak-loblolly pine, (13) basket oak, (14) sugar maple-basswood, and (15) tulip poplar. The associations differ from each other in species composition and in abundances of species common to many associations. Each was identified in the field by the presence of relatively few common discontinuous tree species referred to as characteristic species. Correlations between forest associations and geologic, topographic, and soils units mapped at a similar scale suggest that patterns of available water are important in controlling distribution of woody species throughout Maryland.

  17. [Neurological syndromes linked with the intake of plants and fungi containing a toxic component (I). Neurotoxic syndromes caused by the ingestion of plants, seeds and fruits].

    TOXLINE Toxicology Bibliographic Information

    Carod-Artal FJ

    2003-05-01

    INTRODUCTION: A wide range of plants, seeds and fruits used for nutritional and medicinal purposes can give rise to neurotoxic symptoms.DEVELOPMENT: We review the neurological pathology associated with the acute or chronic consumption of plants, seeds and fruits in human beings and in animals. Of the plants that can trigger acute neurotoxic syndromes in humans, some of the most notable include Mandragora officinalis, Datura stramonium, Conium maculatum (hemlock), Coriaria myrtifolia (redoul), Ricinus communis, Gloriosa superba, Catharanthus roseus, Karwinskia humboldtiana and Podophyllum pelatum. We also survey different neurological syndromes linked with the ingestion of vegetable foodstuffs that are rich in cyanogenic glycosides, Jamaican vomiting sickness caused by Blighia sapida, Parkinson dementia ALS of Guam island and exposition to Cycas circinalis, Guadeloupean parkinsonism and exposition to Annonaceae, konzo caused by ingestion of wild manioc and neurolathyrism from ingestion of Lathyrus sativus, the last two being models of motor neurone disease. Locoism is a chronic disease that develops in livestock feeding on plants belonging to Astragalus and Oxytropis sp., Sida carpinifolia and Ipomea carnea, which are rich in swainsonine, a toxin that inhibits the enzyme alpha mannosidase and induces a cerebellar syndrome.CONCLUSIONS: The ingestion of neurotoxic seeds, fruits and plants included in the diet and acute poisoning by certain plants can give rise to different neurological syndromes, some of which are irreversible.

  18. A novel microphysiometer based on MLAPS for drugs screening.

    PubMed

    Yicong, W; Ping, W; Xuesong, Y; Qingtao, Z; Rong, L; Weimin, Y; Xiaoxiang, Z

    2001-06-01

    This paper presents a novel microphysiometer for simultaneous measurements of several extracellular ions concentrations in living cells based on MLAPS (multi-light addressable potentiometric sensor). In the microphysiometer, different sensitive membranes are illuminated in parallel with n light sources at different frequencies, the response amplitudes of each frequency component can be measured on-line by parallel processing algorithm. By the experiments, we can analyze the relations of the extracellular environmental H(+), Na(+), K(+), Ca(2+) under the effects of western medicines (dilantin, phenobarbital sodium, penicillin sodium) and Chinese drugs (scutellaria, medlar, hemlock parsley), and estimate the effects of several drugs. As the novel microphysiometer works under regular cell culture conditions, cells can be repeatedly simulated with drugs to complete dose-response curve within a few hours. With the detection of a general parameter (extruded protons and ions), the system can be used to monitor the real-time process of the cells' metabolism, observe the functional responses of different kinds of membrane-bound receptors, evaluate the drugs. PMID:11390215

  19. An Appraisal of the Classic Forest Succession Paradigm with the Shade Tolerance Index

    PubMed Central

    Lienard, Jean; Florescu, Ionut; Strigul, Nikolay

    2015-01-01

    In this paper we revisit the classic theory of forest succession that relates shade tolerance and species replacement and assess its validity to understand patch-mosaic patterns of forested ecosystems of the USA. We introduce a macroscopic parameter called the “shade tolerance index” and compare it to the classic continuum index in southern Wisconsin forests. We exemplify shade tolerance driven succession in White Pine-Eastern Hemlock forests using computer simulations and analyzing approximated chronosequence data from the USDA FIA forest inventory. We describe this parameter across the last 50 years in the ecoregions of mainland USA, and demonstrate that it does not correlate with the usual macroscopic characteristics of stand age, biomass, basal area, and biodiversity measures. We characterize the dynamics of shade tolerance index using transition matrices and delimit geographical areas based on the relevance of shade tolerance to explain forest succession. We conclude that shade tolerance driven succession is linked to climatic variables and can be considered as a primary driving factor of forest dynamics mostly in central-north and northeastern areas in the USA. Overall, the shade tolerance index constitutes a new quantitative approach that can be used to understand and predict succession of forested ecosystems and biogeographic patterns. PMID:25658092

  20. Geological and Geothermal Investigation of the Lower Wind River Valley, Southwestern Washington Cascade Range

    SciTech Connect

    Berri, Dulcy A.; Korosec, Michael A.

    1983-01-01

    The Wind River Valley, on the west slope of the Cascade Range, is a northwest-trending drainage that joins the Columbia River near Carson, Washington. The region has been heavily dissected by fluvial and glacial erosion. Ridges have sharp crests and deep subsidiary valleys typical of a mature topography, with a total relief of as much as 900 m. The region is vegetated by fir and hemlock, as well as dense, brushy ground-cover and undergrowth. The lower 8 km of the valley is privately owned and moderately populated. The upper reaches lies within the Gifford Pinchot National Forest, and include several campgrounds and day parks, the Carson National Fish Hatchery, and the Wind River Ranger Station and Wind River Nursery of the US Forest Service. Logging activity is light due to the rugged terrain, and consequently, most valley slopes are not accessible by vehicle. The realization that a potential for significant geothermal resources exists in the Wind River area was brought about by earlier exploration activities. Geologic mapping and interpretation was needed to facilitate further exploration of the resource by providing a knowledge of possible geologic controls on the geothermal system. This report presents the detailed geology of the lower Wind River valley with emphasis on those factors that bear significantly on development of a geothermal resource.

  1. Intraspecific variation in sapling mortality and growth predicts geographic variation in forest composition

    SciTech Connect

    Kobe, R.K.

    1996-05-01

    With a view toward understanding variation in species composition among different forest communities, I examined species-specific growth and mortality of juvenile tree (2.3-78 mm diameter at 10cm above the ground) at three contrasting sites. Two sites differing in soil mineralogy and elevation (schists/gneiss uplands vs. calcareous bedrock valley) were situated in northwestern Connecticut, USA. To examine variation over a more extensive geographic scale, I located the third site in central-western Michigan, USA. Among the three sites, the deciduous species (American beech, white ash, and sugar maple) showed little intraspecific variation in models of relative radial growth at the Michigan site could be explained by sapling growth models originally calibrated for the Connecticut sites. in contrast to the deciduous species, the evergreen species (white pine and eastern hemlock) exhibited between the two Connecticut sites. Intraspecific species, mortality processes exhibited more variation among the sites than did growth. I found significant site differences in mortality as a function of recent growth for both sugar maple and white ash on the calcareous soils in comparison to the schist/gneiss soils in Connecticut site were similar, and both differed from the Connecticut calcareous site. 65 refs., 13 figs., 6 tabs.

  2. Rapid Vegetational Change in Coastal North America: The Response to Climate Since the LGM

    NASA Technical Reports Server (NTRS)

    Peteet, Dorothy; Kneller, Margaret

    1999-01-01

    The late-glacial interval provided rapid shifts in climate which are mirrored by dramatic vegetational changes in North America. Through a transect of lake and mire sites from Connecticut to Virginia on the east coast and Kodiak Island on the western coast, we trace the warming following the LGM with the response of forests and tundra. A brief cold reversal in Virginia is seen from 12,260 to 12,200. The subsequent longer and extreme Younger Dryas event is marked in the southern New England - New Jersey region by dramatic boreal and deciduous forest changes. In the southeastern US, forests also change rapidly, with hemlock forest expansion suggesting increased moisture. In Kodiak Island, the warm, moist tundra of the Bolling/Allerod is replaced by colder, windswept Empetrum-dominated tundra during the Younger Dryas. The Pleistocene/Holocene shift in vegetation is remarkably pronounced in eastern North America as well as the Alaskan coastline. Response time of vegetation to climate change appears to be on the order of decades throughout these coastal locations, probably because of the proximity of sites to important ecotonal boundaries, and the magnitude of the events. Even in Virginia's Holocene record, a cold reversal inferred from increases in spruce and fir is noted at 7500 C14 yr BP. This response of the forests to a short-lived cooling shows the sensitivity of the biosphere to a rapid climate shifts.

  3. Mercury sensing and toxicity studies of novel latex fabricated silver nanoparticles.

    PubMed

    Borase, Hemant P; Patil, Chandrashekhar D; Salunkhe, Rahul B; Suryawanshi, Rahul K; Salunke, Bipinchandra K; Patil, Satish V

    2014-11-01

    Safe and eco-friendly alternatives to currently used hazardous chemico-physical methods of silver nanoparticles (AgNPs) synthesis are need of time. Rapid, low cost, selective detection of toxic metals in environmental sample is important to take safety action. Toxicity assessment of engineered AgNPs is essential to avoid its side effects on human and non-target organisms. In the present study, biologically active latex from Euphorbia heterophylla (Poinsettia) was utilized for synthesis of AgNPs. AgNPs was of spherical shape and narrow size range (20-50 nm). Occurrence of elemental silver and crystalline nature of AgNPs was analyzed. Role of latex metabolites in reduction and stabilization of AgNPs was analyzed by FT-IR, protein coagulation test and phytochemical analysis. Latex-synthesized AgNPs showed potential in selective and sensitive detection of toxic mercury ions (Hg(2+)) with limit of detection around 100 ppb. Addition of Hg(2+) showed marked deviation in color and surface plasmon resonance spectra of AgNPs. Toxicity studies on aquatic non-target species Daphnia magna showed that latex-synthesized AgNPs (20.66 ± 1.52% immobilization) were comparatively very less toxic than chemically synthesized AgNPs (51.66 ± 1.52% immobilization). Similarly, comparative toxicity study on human red blood cells showed lower hemolysis (4.46 ± 0.01%) by latex-synthesized AgNPs as compared to chemically synthesized AgNPs causing 6.14 ± 0.01% hemolysis. PMID:24803140

  4. The stomatal CO2 proxy does not saturate at high atmospheric CO2 concentrations: evidence from stomatal index responses of Araucariaceae conifers.

    PubMed

    Haworth, Matthew; Elliott-Kingston, Caroline; McElwain, Jennifer C

    2011-09-01

    The inverse relationship between the number of stomata on a leaf surface and the atmospheric carbon dioxide concentration ([CO(2)]) in which the leaf developed allows plants to optimise water-use efficiency (WUE), but it also permits the use of fossil plants as proxies of palaeoatmospheric [CO(2)]. The ancient conifer family Araucariaceae is often represented in fossil floras and may act as a suitable proxy of palaeo-[CO(2)], yet little is known regarding the stomatal index (SI) responses of extant Araucariaceae to [CO(2)]. Four Araucaria species (Araucaria columnaris, A. heterophylla, A. angustifolia and A. bidwillii) and Agathis australis displayed no significant relationship in SI to [CO(2)] below current ambient levels (~380 ppm). However, representatives of the three extant genera within the Araucariaceae (A. bidwillii, A. australis and Wollemia nobilis) all exhibited significant reductions in SI when grown in atmospheres of elevated [CO(2)] (1,500 ppm). Stomatal conductance was reduced and WUE increased when grown under elevated [CO(2)]. Stomatal pore length did not increase alongside reduced stomatal density (SD) and SI in the three araucariacean conifers when grown at elevated [CO(2)]. These pronounced SD and SI reductions occur at higher [CO(2)] levels than in other species with more recent evolutionary origins, and may reflect an evolutionary legacy of the Araucariaceae in the high [CO(2)] world of the Mesozoic Era. Araucariacean conifers may therefore be suitable stomatal proxies of palaeo-[CO(2)] during periods of "greenhouse" climates and high [CO(2)] in the Earth's history. PMID:21461935

  5. Agricultural impacts of glyphosate-resistant soybean cultivation in South America.

    PubMed

    Cerdeira, Antonio L; Gazziero, Dionsio L P; Duke, Stephen O; Matallo, Marcus B

    2011-06-01

    In the 2009/2010 growing season, Brazil was the second largest world soybean producer, followed by Argentina. Glyphosate-resistant soybeans (GRS) are being cultivated in most of the soybean area in South America. Overall, the GRS system is beneficial to the environment when compared to conventional soybean. GRS resulted in a significant shift toward no-tillage practices in Brazil and Argentina, but weed resistance may reduce this trend. Probably the highest agricultural risk in adopting GRS in Brazil and South America is related to weed resistance due to use of glyphosate. Weed species in GRS fields have shifted in Brazil to those that can more successfully withstand glyphosate or to those that avoid the time of its application. Five weed species, in order of importance, Conyza bonariensis (L.) Cronquist, Conyza canadensis (L.) Cronquist, Lolium multiflorum Lam., Digitaria insularis (L.) Mez ex Ekman, and Euphorbia heterophylla L., have evolved resistance to glyphosate in GRS in Brazil. Conyza spp. are the most difficult to control. A glyphosate-resistant biotype of Sorghum halepense L. has evolved in GRS in Argentina and one of D. insularis in Paraguay. The following actions are proposed to minimize weed resistance problem: (a) rotation of GRS with conventional soybeans in order to rotate herbicide modes of action; (b) avoidance of lower than recommended glyphosate rates; (c) keeping soil covered with a crop or legume at intercrop intervals; (d) keeping machinery free of weed seeds; and (d) use of a preplant nonselective herbicide plus residuals to eliminate early weed interference with the crop and to minimize escapes from later applications of glyphosate due to natural resistance of older weeds and/or incomplete glyphosate coverage. PMID:20839871

  6. Traditional medicine practitioners knowledge and views on treatment of pregnant women in three regions of Mali

    PubMed Central

    2013-01-01

    Background Despite the widespread use of medicinal plants in Mali, knowledge about how traditional practitioners (TPs) treat pregnant and lactating women is lacking. Aim of the study The aim of this study was to investigate how traditional practitioners in Mali treat common diseases and ailments during pregnancy. Methods Data was collected through structured interviews of traditional practitioners in one urban (Bamako) and two rural areas (Siby and Dioila) in Mali. The TPs were interviewed about how they treat common diseases and ailments during pregnancy. They were also asked to name harmful plants in pregnancy and plants that could affect breast milk production. In addition, we asked about nine specific medicinal plants commonly used in Mali; Opilia amentacea (syn. Opilia celtidifolia), Ximenia americana, Cola cordifolia, Combretum glutinosum, Parkia biglobosa, Trichilia emetica, Combretum micranthum, Lippia chevalieri and Vepris heterophylla. Results A total of 72 traditional practitioners (64% women, age: 34 to 90 years) were interviewed during an eight week period October 2011 to December 2011. They treated between 1 and 30 pregnant women with medicinal plants per months. We found a relatively high consensus for treatment of pregnant women with common diseases and ailments like nausea and dermatitis. The highest informer consensus was found for the treatment of malaria during pregnancy. TPs generally recommended pregnant women to avoid medicinal plants with bitter tastes like stem and root bark of Khaya senegalensis and Opilia amentacea (syn. Opilia celtidifolia). TPs distinguished between oral (potentially unsafe) and dermal use (safe) of Opilia amentacea (syn. Opilia celtidifolia). Cola cordifolia was used to facilitate labor. Conclusion Experience and knowledge about treatment of pregnant women with medicinal plants was broad among the traditional practitioners in the three investigated regions in Mali. Collaborating with traditional practitioners on the safe use of medicinal plants in pregnancy may promote safer pregnancies and better health for mothers and their unborn infants in Mali. PMID:24041441

  7. Drought avoidance and vulnerability in the Australian Araucariaceae.

    PubMed

    Zimmer, Heidi C; Brodribb, Tim J; Delzon, Sylvain; Baker, Patrick J

    2016-02-01

    The Araucariaceae is an iconic tree family. Once globally important, the Araucariaceae declined dramatically over the Cenozoic period. Increasing aridity is thought to be responsible for extinction and range contraction of Araucariaceae in Australia, yet little is known about how these trees respond to water stress. We examined the response to water stress of the recently discovered tree Wollemia nobilis Jones, W.G., Hill, K.D. & Allen, J.M. (Araucariaceae) and two closely related and widespread tree species, Araucaria bidwillii Hook. and Araucaria cunninghamii Mudie, and the island-endemic species, Araucaria heterophylla (Salisb.) Franco. Leaf water potential in all Araucaria spp. remained remarkably unchanged during both dehydration and rehydration, indicating strong isohydry. The xylem tensions at which shoot and stem hydraulic conductances were reduced to 50% (P50shoot and P50stem) were closely correlated in all species. Among the four species, W. nobilis exhibited greater resistance to xylem hydraulic dysfunction during water stress (as indicated by P50shoot and P50stem). Unexpectedly, W. nobilis also experienced the highest levels of crown mortality in response to dehydration, suggesting that this was the most drought-sensitive species in this study. Our results highlight that single traits (e.g., P50) should not be used in isolation to predict drought survival. Further, we found no clear correlation between species' P50 and rainfall across their distributional range. Diversity in drought response among these closely related Araucariaceae species was surprisingly high, considering their reputation as a functionally conservative family. PMID:26612850

  8. Cyclization of several linear penta- and heptapeptides with different metal ions studied by CD spectroscopy.

    PubMed

    Liu, M; Tang, Y-C; Fan, K-Q; Jiang, X; Lai, L-H; Ye, Y-H

    2005-01-01

    A cyclic pentapeptide c(Tyr-Leu-Ala-Gly-Pro) (I), which was isolated and identified from Pseudostellaria heterophylla medicinal herbs, and two cyclic heptapeptides, c(Gly-Tyr-Gly-Gly-Pro-Phe-Pro) (II) and c(Gly-Ile-Pro-Tyr-Ile-Ala-Ala) (III), which were isolated and identified from Stellaria yunnanensis Franch (M), were synthesized by using 3-(diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3 H)-one (DEPBT) as a coupling reagent in solution, and mediated by different metal ions, from their linear peptide precursors H-Tyr-Leu-Ala-Gly-Pro-OH (I-1) and H-Ala-Gly-Pro-Tyr-Leu-OH (I-2), H-Gly-Tyr-Gly-Gly-Pro-Phe-Pro-OH (II-1) and H-Gly-Ile-Pro-Tyr-Ile-Ala-Ala-OH (III-1), respectively. The results show that alkali metal ions can improve the cyclization yields and/or the cyclization rates of linear peptide precursors, such as Na(+) ion is favorable for the cyclization of linear pentapeptides and Cs(+) ion is favorable for the cyclization of linear heptapeptides, while some bivalent and trivalent metal ions, such as Mg(2+), Ca(2+), Zn(2+), Fe(2+), Ni(2+) and Cr(3+) reduced/inhibited both the cyclization yields and the cyclization rates of the linear peptide precursors. The circular dichroism spectra of I-1, II-1 and III-1 with different metal ions were studied to elucidate the changes in their secondary structures. It is shown that Cs(+) can induce and stabilize the type I beta-turn conformation in the linear heptapeptide II-1 and the type II beta-turn conformation in the linear heptapeptide III-1. PMID:15686535

  9. [Difference in responses of major tree species growth to climate in the Miyaluo Mountains, western Sichuan, China].

    PubMed

    Guo, Ming-ming; Zhang, Yuan-dong; Wang, Xiao-chun; Liu, Shi-rong

    2015-08-01

    To explore the responses of different tree species growth to climate change in the semi-humid region of the eastern Tibetan Plateau, we investigated climate-growth relationships of Tsuga chinensis, Abies faxoniana, Picea purpurea at an altitude of 3000 m (low altitude) and A. faxoniana and Larix mastersiana at an altitude of 4000 m (high altitude) using tree ring-width chronologies (total of 182 cores) developed from Miyaluo, western Sichuan, China. Five residual chronologies were developed from the cross-dated ring width series using the program ARSTAN, and the relationships between monthly climate variables and tree-ring index were analyzed. Results showed that the chronologies of trees at low altitudes were negatively correlated with air temperature but positively with precipitation in April and May. This indicated that drought stress limited tree growth at low altitude, but different tree species showed significant variations. T. chinensis was most severely affected by drought stress, followed by A. faxoniana and P. purpurea. Trees at high altitude were mainly affected by growing season temperature. Tree-ring index of A. faxoniana was positively correlated with monthly minimum temperature in February and July of the current year and monthly maximum temperature in October of the previous year. Radial growth of L. mastersiana was positively correlated with monthly maximum temperature in May, and negatively with monthly mean temperature in February and monthly minimum temperature in March. In recent decadal years, the climate in northeast Tibetan Plateau had a warming and drying trend. If this trend continues, we could deduce that P. purpurea should grow faster than T. chinensis and A. faxoniana at low altitudes, while A. faxoniana would benefit more from global warming at high altitudes. PMID:26685584

  10. Postglacial Vegetation and Climate of the Cascade Range, Central Oregon

    NASA Astrophysics Data System (ADS)

    Sea, Debra S.; Whitlock, Cathy

    1995-05-01

    Pollen data from two sites provide information on the postglacial vegetation and climate history of the Cascade Range. Indian Prairie in the western Cascade Range was colonized by subalpine forests of Pinus, Picea, and Tsuga and open meadows prior to ca. 12,400 14C yr B.P. The treeline lay 500 to 1000 m below its modern elevation and conditions were cooler than at present. From ca. 12,400 to ca. 9950 14C yr B.P. Abies became important and the forest resembled that presently found at middle elevations in the western Cascade Range. The pollen record implies a rise in treeline and warmer conditions than before. From ca. 10,000 to 4000-4500 14C yr B.P., conditions that were warmer and effectively drier than today led to the establishment of a closed forest composed of Pseudotsuga , Abies, and, at lower elevations, Quercus and Corylus . During this period, Gold Lake Bog in the High Cascades was surrounded by closed forest of Pinus and Abies. The early-Holocene pollen assemblages at both Indian Prairie and Gold Lake Bog lack modern analogues, and it is likely that greater-than-present summer radiation fostered unique climatic conditions and vegetation associations at middle and high elevations. In the late Holocene, beginning ca. 4000-4500 14C yr B.P., cooler and more humid conditions prevailed and the modern vegetation was established. A comparison of these sites with others in the Pacific Northwest suggests that major patterns of vegetational change at individual sites were a response to large-scale changes in the climate system that affected the entire region.

  11. Distribution and hosts of Callidiellum rufipenne (Coleoptera: Cerambycidae), an asian cedar borer established in the eastern United States.

    PubMed

    Maier, Chris T

    2007-08-01

    The distribution and hosts of the exotic cedar-boring beetle, Callidiellum rufipenne (Motschulsky) (Coleoptera: Cerambycidae), were determined in five northeastern U.S. states by capturing adults on cedar trap logs and by rearing adults from various conifers. This beetle was detected in the coastal states of Massachusetts, Rhode Island, Connecticut, New York, and New Jersey. In these states, adults emerged from the live or dead wood of four genera and eight species of Cupressaceae; species of Pinaceae were not hosts. Through its entire range, C. rufipenne is reported to infest at least 14 species of Cupressaceae, four species of Pinaceae, and one species of Taxaceae; but, records of Pinaceae and possibly Taxaceae are suspect. Based on the number of adults that emerged from coniferous poles in a five-way choice test in the field, the infestation level was significantly greater in Chamaecyparis thyoides (L.) Britton, Sterns, and Poggenburg and Juniperus virginiana L. than in Pinus rigida Miller, Pinus strobus L., and Tsuga canadensis (L.) Carribre (last three species uninfested). In a second test of host preference in the wild, beetles infested four cupressaceous species, but not Abies balsamea (L.) Miller, Picea rubens Sargent, Pinus rigida, P. strobus, and Ts. canadensis in the Pinaceae. Infestation level was highest in Ch. thyoides, followed in decreasing order by Juniperus communis L., Thuja occidentalis L., and J. virginiana. In a comparison of live and dead J. virginiana, beetles developed to adults only in dead trees (36 beetles per tree). When trunk sections of Th. occidentalis with and without bark were offered to females in cages, beetles of the next generation emerged exclusively from wood with bark. In the Northeast, only species of Cupressaceae apparently are suitable hosts for C. rufipenne. Infestation of these species may be prevented or reduced by proper care of live plants and by debarking trees after harvesting. PMID:17849882

  12. Estimation of light interception properties of conifer shoots by an improved photographic method and a 3D model of shoot structure.

    PubMed

    Thérézien, Mathieu; Palmroth, Sari; Brady, Rachael; Oren, Ram

    2007-10-01

    The spherical mean of the shoot silhouette-to-total leaf area ratio (STAR) and the shoot transmission coefficient (c) are two key structural parameters in radiative transfer models for calculating canopy photosynthesis and leaf area index. The standard optical method for estimating these parameters might introduce errors in the estimates for species with flexible shoots and needles by changing shoot inclination relative to its inclination in situ. We devised and tested two methods to address this problem. First, we modified the standard optical method by designing an apparatus that allows shoots to be photographed in their original orientation. Second, we developed a faster, model-based approach to replace photography and tested the results against the established approach. We used shoots of three pine species, Pinus echinata Mill. (needle length ~50 mm), P. taeda L. (~150 mm) and P. palustris Mill. (~300 mm). Values of the parameters simulated by the model were similar to those measured from the photographs. In our data, STAR varied about twofold among the pine species and was ~40% higher in shade shoots than in sun shoots of P. taeda. The transmission coefficient for P. taeda shade shoots was also ~40% higher than that of sun shoots of all three species. We tested the versatility of the model by employing it on shoots of two other pine species (P. strobus L. and P. thumbergiana Parl.) as well as on shoots of Tsuga canadensis L. Carr. and Picea pungens Engelm. Regardless of shoot characteristics, the model generated values of shoot structural parameters similar to those estimated with the optical method. Although species-specific and vertical gradients in parameter values are best for modeling radiative transfer in conifer canopies, our results suggest that, in the absence of adequate data, STAR can be approximated as 0.16 for a wide range of shoot structures. For applications requiring angle-dependent parameterization, our new model facilitates rapid generation of these radiative transfer parameters. PMID:17669728

  13. Survival and development of Lymantria monacha (Lepidoptera: Lymantriidae) on North American and introduced Eurasian tree species.

    PubMed

    Keena, M A

    2003-02-01

    Lymantria monacha (L.) (Lepidoptera: Lymantriidae), the nun moth, is a Eurasian pest of conifers that has potential for accidental introduction into North America. To project the potential host range of this insect if introduced into North America, survival and development of L. monacha on 26 North American and eight introduced Eurasian tree species were examined. Seven conifer species (Abies concolor, Picea abies, P. glauca, P. pungens, Pinus sylvestris with male cones, P. menziesii variety glance, and Tsuga canadensis) and six broadleaf species (Betula populifolia, Malus x domestica, Prunus serotiaa, Quercus lobata, Q. rubra, and Q. velutina) were suitable for L. monacha survival and development. Eleven of the host species tested were rated as intermediate in suitability, four conifer species (Larix occidentalis, P. nigra, P. ponderosa, P. strobus, and Pseudotsuga menziesii variety menziesii) and six broadleaf species (Carpinus caroliniana, Carya ovata, Fagus grandifolia, Populus grandidentata, Q. alba, and Tilia cordata) and the remaining 10 species tested were rated as poor (Acer rubrum, A. platanoidies, A. saccharum, F. americana, Juniperus virginiana, Larix kaempferi, Liriodendron tulipfera, Morus alba, P. taeda, and P. deltoides). The phenological state of the trees had a major impact on establishment, survival, and development of L. monacha on many of the tree species tested. Several of the deciduous tree species that are suitable for L. monacha also are suitable for L. dispar (L.) and L. mathura Moore. Establishment of L. monacha in North America would be catastrophic because of the large number of economically important tree species on which it can survive and develop, and the ability of mated females to fly and colonize new areas. PMID:12650343

  14. Is worst-case scenario streamflow drought underestimated in British Columbia? A multi-century perspective for the south coast, derived from tree-rings

    NASA Astrophysics Data System (ADS)

    Coulthard, Bethany; Smith, Dan J.; Meko, David M.

    2016-03-01

    Recent streamflow droughts in south coastal British Columbia have had major socioeconomic and ecological impacts. Increasing drought severity under projected climate change poses serious water management challenges, particularly in the small coastal watersheds that serve as primary water sources for most communities in the region. A 332-year dendrohydrological record of regionalized mean summer streamflow for four watersheds is analyzed to place recent drought magnitudes in a long-term perspective. We present a novel approach for optimizing tree-ring based reconstructions in small watersheds in temperate environments, combining winter snow depth and summer drought sensitive proxies as model predictors. The reconstruction model, estimated by regression of observed flows on Tsuga mertensiana ring-width variables and a tree-ring derived paleorecord of the Palmer Drought Severity Index, explains 64% of the regionalized streamflow variance. The model is particularly accurate at estimating lowest flow events, and provides the strongest annually resolved paleohydrological record in British Columbia. The extended record suggests that since 1658 sixteen natural droughts have occurred that were more extreme than any within the instrumental period. Flow-duration curves show more severe worst-case scenario droughts and a higher probability of those droughts in the long-term reconstruction than in the hydrometric data. Such curves also highlight the value of dendrohydrology for probabilistic drought assessment. Our results suggest current water management strategies based on worst-case scenarios from historical gauge data likely underestimate the potential magnitudes of natural droughts. If the low-flow magnitudes anticipated under climate change co-occur with lowest possible natural flows, streamflow drought severities in small watersheds in south coastal British Columbia could exceed any of those experienced in the past ∼350 years.

  15. The Abrupt Climatic Changes During the Last Deglaciation: Direct Land-sea Correlation From a Marine Pollen Record off Southeastern United States

    NASA Astrophysics Data System (ADS)

    Desprat, S.; McManus, J. F.; Peteet, D.

    2007-12-01

    We present a new direct land-sea correlation covering the last deglaciation in order a) to provide a better documentation of the regional vegetation changes in southeastern North America and b) more particularly to assess the connection of the continental climatic changes to North Atlantic circulation rapid variability. It was achieved using coupled analyses of pollen and marine climatic proxies from core KNR140-GGC39 (Blake Outer Ridge) at very high time-resolution. Mg/Ca ratio, planktonic ?18O, mean "sortable silt" grain size (mean SS) were analyzed in order to get records of SST, salinity and bottom current strength at the core site (Evans et al., submitted to Paleoceanography). The abrupt climatic changes which characterize the last deglaciation, in particular the major cold oscillations Heinrich event 1 (H1) and Younger Dryas (YD), have been widely documented in the North Atlantic and adjacent continents. However, in the tropical and subtropical North Atlantic and southeastern United States, the climatic signature of these events appears quite different and somehow unclear. Our direct land-sea correlation shows three configurations: 1- H1 period: cold climatic conditions in southeastern US (high percentages of boreal and herbaceous taxa) but only extremely cold at around 17 ka, accumulation of salty water in the subtropics (high ?18OSW- IVC) and weak bottom current intensity at the site (low mean SS) 2- Bolling Allerd interval: abrupt warming in southeastern US (decrease of boreal taxa in favour of Quercus) at the beginning, synchronous to northern export of the salty water previously accumulated and to an increase of the bottom current strength at the site 3- YD period: mild and wet conditions in southeastern US (expansion of Tsuga and Quercus), decrease of the bottom current strength at the site and accumulation of salty water in the subtropical regions but less than during H1.

  16. [Quantitative analysis of different restoration stages during natural succession processes of subalpine dark brown coniferous forests in western Sichuan, China].

    PubMed

    Ma, Jiang-Ming; Liu, Shi-Rong; Shi, Zuo-Min; Zhang, Yuan-Dong; Chen, Bao-Yu

    2007-08-01

    By adopting space as a substitute for time, and based on the approaches of inter-specific association, PCA and optimal division, the restoration stages of various secondary forest communities originated from the natural succession processes of bamboo-dark brown coniferous and moss-dark brown coniferous old-growth forests after clear-cut were quantified at different temporal series (20, 30, 30, 40, 50 and 160-200 years). The results showed that Betula albo-sinensis, Salix rehderiana, Acer mono, A. laxiflorum, Prunus tatsienensis, Hydrangea xanthoneura, Tilia chinensis and Salix dolia were the declining species groups with progressive restoration processes from secondary forest to mature moss and bamboo-dark brown coniferous forests, Sorbus hupehensis, S. koehneana and P. pilosiuscula were the transient species groups, and Abies faxoniana, Picea purpurea, Tsuga chinensis and P. wilsonii were the progressive species groups. During the period of 20-40 years restoration, the secondary forests were dominated by broad-leaved tree species, such as B. albo-sinensis, and the main forest types were moss--B. albo-sinensis forest and bamboo--B. albo-sinensis forest. Through 50 years natural succession, the secondary forests turned into conifer/broad-leaved mixed forest dominated by B. albo-sinensis and A. faxoniana, and the main forest types were moss--B. albo-sinensis--A. faxoniana forest and bamboo--B. albo-sinensis--A. faxoniana forest. The remained 160-200 years old coniferous forests without cutting were dominated by old-growth stage A. faxoniana, and the main forest types were moss--A. faxoniana forest and bamboo--A. faxoniana forest. PMID:17974231

  17. Macroscale intraspecific variation and environmental heterogeneity: analysis of cold and warm zone abundance, mortality, and regeneration distributions of four eastern US tree species.

    PubMed

    Prasad, Anantha M

    2015-11-01

    I test for macroscale intraspecific variation of abundance, mortality, and regeneration of four eastern US tree species (Tsuga canadensis,Betula lenta,Liriodendron tulipifera, and Quercus prinus) by splitting them into three climatic zones based on plant hardiness zones (PHZs). The primary goals of the analysis are to assess the differences in environmental heterogeneity and demographic responses among climatic zones, map regional species groups based on decision tree rules, and evaluate univariate and multivariate patterns of species demography with respect to environmental variables. I use the Forest Inventory Analysis (FIA) data to derive abundance, mortality, and regeneration indices and split the range into three climatic zones based on USDA PHZs: (1) cold adapted, leading region; (2) middle, well-adapted region; and (3) warm adapted, trailing region. I employ decision tree ensemble methods to assess the importance of environmental predictors on the abundance of the species between the cold and warm zones and map zonal variations in species groups. Multivariate regression trees are used to simultaneously explore abundance, mortality, and regeneration in tandem to assess species vulnerability. Analyses point to the relative importance of climate in the warm adapted, trailing zone (especially moisture) compared to the cold adapted, leading zone. Higher mortality and lower regeneration patterns in the warm trailing zone point to its vulnerability to growing season temperature and precipitation changes that could figure more prominently in the future. This study highlights the need to account for intraspecific variation of demography in order to understand environmental heterogeneity and differential adaptation. It provides a methodology for assessing the vulnerability of tree species by delineating climatic zones based on easily available PHZ data, and FIA derived abundance, mortality, and regeneration indices as a proxy for overall growth and fitness. Based on decision tree rules, ecologically meaningful variations in species abundance among the climatic zones can be related to environmental variability and mapped. PMID:26640680

  18. Redox potential: An indicator of site productivity in forest management

    NASA Astrophysics Data System (ADS)

    Sajedi, Toktam; Prescott, Cindy; Lavkulich, Les

    2010-05-01

    Redox potential (Eh) is an integrated soil measurement that reflects several environmental conditions in the soil associated with aeration, moisture and carbon (organic matter) dynamics. Its measurement can be related to water table fluctuations, precipitation and landscape gradients, organic matter decomposition rates, nutrient dynamics, biological diversity and plant species distribution. Redox is an excellent indicator of soil biological processes, as it is largely a reflection of microbial activities which to a large extent govern carbon dynamics and nutrient cycling. Redox thus serves as an ecological indicator of site productivity at the ecosystem scale and may be used for management purposes as its magnitude can be altered by activities such as harvesting and drainage. A threshold value of 300 mv has been documented as the critical value below which anaerobic conditions in the soil develop. However, redox measurements and its impacts on ecosystem processes such as nutrient cycling and productivity, especially in forest ecosystems, have not received the attention that this "master" variable deserves, On northern Vancouver Island, Canada, regenerating stands of western redcedar-western hemlock (CH) sites exhibit symptoms of nutrient deficiencies and slow growth, but this phenomenon does not occur on adjacent western hemlock- amabalis fir (HA) sites. We tested the hypothesis that differences in nutrient supply and distribution of plant species was caused by differences in moisture regime and redox potential. Redox potential, pH, soil aeration depth (steel rods), organic matter thickness, bulk density, soil carbon store, plant species distribution and richness were measured at five old-growth and five 10-year-old cutover blocks. Results of investigations confirmed that CH forests were wetter, had redox values lower than the critical 300mv and a shallower aerated zone, compared with adjacent regenerating HA sites. Fifty percent of the CH plots had redox values less than +300 mv in the forest floor; whereas only 15 percent of the HA plots had such low values. Composition of the forest understory species was related to soil moisture/aeration. Soil aeration was the most important soil variable influencing plant species composition, explaining 25% of the plant community variability. Eh was always greater than +300 mv in the mineral soil of old growth HA forests but below +300 mv in HA clearcuts, suggesting paludification; however it was below or at this threshold in both CH forests and clearcuts. The reduction in measured redox without a noticeable change in the watertable in HA sites suggests that harvesting HA forests shifts the ecosystem towards more anaerobic conditions more similar to CH sites. In a complimentary study, the significance of redox was assessed in a cedar swamp cutover by exploring the relationships between soil redox potential and tree growth, and mineralization of C and soil C store along a gradient of moisture caused by drainage. Drainage improved aeration in the rooting zone, expressed as redox, and above- and below ground C storage; however C mineralization measured as CO2 evolution was not affected. Tree growth was positively correlated with redox potential. Our results indicate that drainage could be a useful silvicultural practice for improving the productivity of these ecosystems and that it may be possible to improve tree growth without stimulating loss of soil C. This requires that drainage improve aeration in the rooting zone while maintaining redox levels of less than +300 mV in the bulk soil, indicating that redox measurements should be incorporated into silviculture interventions to improve productivity of these forests.

  19. Kootenai River White Sturgeon Investigations; White Sturgeon Spawning and Recruitment Evaluation, 2004-2005 Annual Report.

    SciTech Connect

    Rust, Pete; Wakkinen, Virginia

    2006-05-01

    The objective of this research was to determine the environmental requirements for successful spawning and recruitment of the Kootenai River white sturgeon Acipenser transmontanus population. Annual tasks include monitoring and evaluating the response of various life stages of Kootenai River white sturgeon to mitigation flows supplied by the United States Army Corps of Engineers (USACE). Sampling for adult Kootenai River white sturgeon in 2004 began in March and continued into May. One hundred forty-two adult white sturgeon were captured with 4,146 hours of angling and set-lining effort in the Kootenai River. Kootenai River discharge and stage at Bonners Ferry in 2004 peaked in mid December. Discharge remained below 400 cubic meters per second (cms) until June 1; then, because of a systems operations request (SOR), increased and remained between 480 and 540 cms through the end of June. From July through September, discharge ranged from 360 to 420 cms, decreasing to 168 cms by the end of October. Discharge increased again to above 625 cms by November 4 to increase winter storage in Lake Koocanusa and ranged from 310 to 925 cms through the end of December. We monitored the movements of 31 adult sturgeon in Kootenay Lake, British Columbia (BC) and the Kootenai River from mid-March until late August 2004. All telemetered fish were dual tagged with external sonic and radio transmitters, and some of the fish were tagged in previous years. Eighteen of the 31 telemetered adult white sturgeon were released at Hemlock Bar reach (rkm 260.0) as part of a research project to test the feasibility of moving sexually mature adult white sturgeon to areas with habitat types thought to be more suitable for successful egg hatching and early life stage recruitment. Marked fish were monitored from the time of release until they moved downstream of Bonners Ferry. Sampling for white sturgeon eggs with artificial substrate mats began May 3 and ended June 10, 2004. We sampled 650 mat days (a mat day is one 24 h set) during white sturgeon spawning. Most of the sampling occurred in the post-Libby dam spawning reach (rkm 229.0 to 246.0) but some sampling occurred near Crossport (rkm 253.5) and in the Canyon reach above Hemlock Bar (rkm 261.0). We collected eight white sturgeon eggs near Shortys Island in 2004. Sampling for larval white sturgeon began June 8 and continued until July 22, 2004. Sampling occurred primarily at Ambush Rock (rkm 244.0) in an attempt to document any recruitment that might have occurred from the Set and Jet Program. We collected 103 larval fish, but none were white sturgeon larvae or embryos. Juvenile white sturgeon sampling started July 26 and continued through September 27, 2004. A total of 271 hours of gillnetting effort captured 256 juvenile hatchery white sturgeon and two juvenile wild white sturgeon.

  20. Fine-scale, multidimensional spatial patterns of forest canopy structure derived from remotely sensed and simulated datasets

    NASA Astrophysics Data System (ADS)

    Frazer, Gordon Wilson

    Forests are not simply storehouses of timber or wood fibre for human consumption and economic development. They represent structurally and ecologically rich habitat for an estimated 40 percent of the earth's extant species, and form the functional interface between the biosphere and atmosphere for some 27 percent of the earth's terrestrial surface. Forests, therefore, play a vital role in the maintenance of biodiversity and the regulation of local to global scale ecosystem processes and functions. Present strategies for conserving biodiversity in managed forests are based on the notion that maintaining the full range of structural conditions historically present in natural forests is the best approach for assuring the long-term persistence of a broad range of native species. The overarching goal of this dissertation is to contribute to the development of novel forest measurements that are relevant to organisms and ecosystems, and much needed by forest scientists and managers to recognize and retain the key elements and patterns of forest structure that are crucial for the conservation of forest biodiversity. This study focuses explicitly on fine-spatial-scale, multidimensional patterns of forest canopy structure based on the assumption that the 'canopy' is the primary focal site of complex interactions between vegetation and the physical environment. Two disparate remote sensing technologies---ground-based hemispherical (fisheye) canopy photography and airborne discrete-return LiDAR---are employed to characterize angular, vertical, and horizontal patterns of forest canopy structure. A quantitative technique is developed for precise measurements of gap fraction (P), element clumping (O), mean projection coefficient (G), and leaf area index (L) from sequences (sets) of black and white pixels extracted at specific view angles in digital fisheye photos. Results are compared with three other leading techniques and validated using well-documented simulated and real fisheye photosets. Variables P, O, G, and L control light capture and penetration in forest canopies, and are key input parameters for process-based models of stand productivity, stand dynamics, and material (CO2 and H2O) and energy fluxes between the canopy and atmosphere. Findings show that this new technique consistently produced the best estimates of stand LAI in each of the three experimental forest sites. However, further validation work is required to determine the adequacy of these methods in other closed and discontinuous canopies. Finally, a methodological framework is devised for quantifying, classifying, and comparing fine-spatial-scale vertical and horizontal patterns of canopy structure derived from airborne LiDAR data. This methodology is tested with simulated forest canopies and ultimately demonstrated using an airborne LiDAR dataset collected over very young to old, coastal Douglas-fir/western hemlock forests on Vancouver Island, British Columbia. A pseudo 'space-for-time substitution' sampling approach is used to investigate age-related developmental changes in canopy structure at decadal and century time scales. Discrete classes of vertical and horizontal canopy structure are identified by k-means partitioning. The structural differences found among age-classes were consistent with the characteristics, patterns, and dynamics predicted by generalized models of stand development for similar coastal Douglas-fir/western hemlock forests of northwestern North America.

  1. Accurate and cost-effective natural resource data from super large scale aerial photography

    NASA Astrophysics Data System (ADS)

    Grotefendt, Richard Alan

    Increasing amounts and types of timely and accurate data are required for monitoring to ensure compliance with natural resource regulatory requirements. This study developed a cost-effective method to partially fulfill these data requirements using super large scale aerial photography (Scale: greater than 1:2,000). Two synchronized, metric, Rolleiflex 70mm (2.76in) cameras mounted 12m (40ft) apart on a rigid platform and carried at 5.6 km/hr (3 knots) by a helicopter collected this high resolution, 3D imagery from Alaska and Washington. The overlapping photo pairs provided 3D views of natural resource objects as fine as twigs. The 12m (40ft) inter-camera distance improved ground visibility between tree crowns of dense old growth forests. Analytical stereoplotters and the application of photogrammetric principles enabled measurement and interpretation of photo objects such as trees and their height in a cost-effective way. Horizontal and vertical measurement accuracy was within 2% and 3% of field measurement, respectively. Forest inventory and riparian buffer monitoring applications were used to test this method. Although field work is still required to develop photo-field relationships unique to each ecosystem and for quality assurance, the photo estimates of individual tree height, volume, diameter, type, and location, as well as down tree decay class and landing spot, plot timber volume, and area were comparable to and may replace approximately 95% of field effort. For example, the average of the absolute differences between field and photo estimates for tree height was 2.4m (7.8ft) (s.d. = 2.1m (6.8ft), n = 376), diameter at breast height (1.4m (4.5ft) above ground on uphill tree side) was 5.8cm (2.3in) (s.d. = 5.6cm (2.2in), n = 109), and plot volume in gross board feet was within 10.9% to 13.4% (n = 10) depending on the estimator used. Forest type was correctly classified 99.4% (n = 180) of the time. Timber inventory, species identification, sample distribution, down wood detection, and mapping of habitat features such as streams and trees provided improvement over field methods alone. For example, tree species was correctly identified 90% (n = 176) of the time for alder, Alaska cedar, lodgepole pine, mountain hemlock, Sitka spruce, western hemlock, and western redcedar. The spatial position of tree bases using digital elevation models was within 2.6m (8.4ft) of the actual position (s.d. = 1.4m (4.5ft), n = 20). Tree height, riparian buffer, and forest inventory plot volume data photo collection costs were one-fourth to one-half those of field methods. The new variables of tree crown closure and tree branch density were developed but did not contribute significantly to tree volume estimation. Physiographic limitations and sampling bias were eliminated by helicopter use.

  2. Western Arctic Vulnerability to Warming over the past 3.6 Myr: Lessons from sediments drilled at Lake El'gygytgyn, Western Beringia

    NASA Astrophysics Data System (ADS)

    Brigham-Grette, J.; Melles, M.; Minyuk, P.; Lake El'gygytgyn Science Team

    2011-12-01

    International Continental Deep drilling (ICDP) at Lake El'gygytgyn (67_30' N, 172_05' E; "Lake E"), recovered lacustrine sediments dating back to 3.6 Ma that provides the first time-continuous Pliocene-Pleistocene paleoclimate record of different interglacials from the terrestrial Arctic. While discontinuous, spatially diverse Pliocene and Pleistocene marine interglacial records are known from the arctic borderlands at the outcrop scale, the Lake El'gygytgyn record is critically important understanding the western Arctic landscape response to different forcing factors operating across the Arctic since the mid-Pliocene warm period. The record is important for evaluating the sensitivity of the Arctic region and to provide a template of Arctic climate variability that can be compared to other regions. Lake E modeling is framed around suites of sensitivity tests of Beringian climate response to the full range of forcing experienced over the last ~3.5 million years using a nested Global-Regional Climate Model (GCM-RCM). The Pliocene portion of the lake record (~3.6-3.0 Ma; a time when atmospheric CO2 levels may have been like today) has nearly twice the sedimentation rate as later Quaternary intervals, partly as a consequence of basin infilling but also presumably due to more rainfall and more active rivers at that time. Studies of spores and pollen from this portion of the core (samples every ~10k) show that the area was once dominated by trees, providing us with the pace of variability in Pliocene Arctic forests, which included species of pine, larch, spruce, fir, alder, and hemlock. Hemlock and tree pine pollen is exceptional for this latitude but the assemblage implies July temperatures nearly 8 degrees warmer than today with ~3 times the annual precipitation. Modeling suggests sustained forests at Lake E in both cold and warm orbits during this interval. The record includes a strong M2 cooling event to conditions like today at ~3.3 Ma, but not glacial climates as some have inferred from marine isotopic data. Warm interglacial portions of the core investigated so far are those correlative with MIS 5e, 9, 11 and 31 that differ in character, due to orbital forcing and feedbacks. The lithofacies can be linked directly to other proxies of climate change and allow us to interpret climatic influences on the watershed as well as changing conditions related to lake productivity, lake ice cover persistence, runoff and clastic input and vegetation in the basin. Multi-proxy evidence shows that interglacials MIS 9, 11 and 31 were remarkably warmer than MIS 5e. A warm MIS 31 at Lake E may have occurred half a precession cycle before the last time ANDRILL shows direct evidence of the collapse of WAIS. MIS 11 shows surprising structural similarities to Lake Baikal and Dome C ice core paleorecords but is remarkably warm. The climate record from Lake E, especially the history of past interglacials, provides a fresh means of testing what controls polar amplification over time.

  3. Biomass accumulation and soil nitrogen availability in an 87-year-old Populus grandidentata chronosequence

    USGS Publications Warehouse

    White, L.L.; Zak, D.R.; Barnes, B.V.

    2004-01-01

    The Upper Lake States region is marked by major disturbances of fire and logging over 100 years ago that created a landscape mosaic of early successional forests. Given the intimate link between soil N availability and forest growth in this region, it is important to understand how temporal changes in soil N constrain the rate at which forest biomass accumulates following a stand-destroying disturbance. Bigtooth aspen (Populus grandidentata Michx.) currently dominates sites where primarily old-growth pine-hemlock-oak forests once thrived, which provides an opportunity to observe nearly 100 years of succession following severe disturbance. In this study, we examine the relationship between soil N availability and biomass accrual in a series of plots undergoing secondary succession following logging and burning. Our results demonstrate that total aboveground biomass and nitrogen accrual patterns are strongly and positively related on a highly disturbed, bigtooth aspen-dominated ecosystem in northern Lower Michigan. Nitrogen mineralization and nitrification were highest immediately following disturbance, and then decreased over the next approximately 20 years of succession. Following this short-term decrease, these processes increased and attained a maximum value after 70 years of forest succession. Understory biomass accumulation showed the opposite trend of nutrient availability, with highest values during the first 20 years of succession, followed by a dramatic decrease for the next 70 years. Understory biomass began to decrease as plants grew into the overstory or died. Total aboveground biomass was correlated with N mineralization (r=0.894; P=0.041) and nitrification (r=0.782; P=0.118) and appears to be increasing steadily to some maximum that has not yet been reached. ?? 2003 Elsevier B.V. All rights reserved.

  4. Nutrient-cycling microbes in coastal Douglas-fir forests: regional-scale correlation between communities, in situ climate, and other factors

    PubMed Central

    Shay, Philip-Edouard; Winder, Richard S.; Trofymow, J. A.

    2015-01-01

    Microbes such as fungi and bacteria play fundamental roles in litter-decay and nutrient-cycling; however, their communities may respond differently than plants to climate change. The structure (diversity, richness, and evenness) and composition of microbial communities in climate transects of mature Douglas-fir stands of coastal British Columbia rainshadow forests was analyzed, in order to assess in situ variability due to different temperature and moisture regimes. We compared denaturing gradient gel electrophoresis profiles of fungi (18S-FF390/FR1), nitrogen-fixing bacteria (NifH-universal) and ammonia-oxidizing bacteria (AmoA) polymerase chain reaction amplicons in forest floor and mineral soil samples from three transects located at different latitudes, each transect spanning the Coastal Western Hemlock and Douglas-fir biogeoclimatic zones. Composition of microbial communities in both soil layers was related to degree days above 0°C (2725–3489), while pH (3.8–5.5) best explained shifts in community structure. At this spatial scale, climatic conditions were likely to directly or indirectly select for different microbial species while local site heterogeneity influenced community structure. Significant changes in microbial community composition and structure were related to differences as small as 2.47% and 2.55°C in mean annual moisture and temperature variables, respectively. The climatic variables best describing microbial composition changed from one functional group to the next; in general they did not alter community structure. Spatial distance, especially associated with latitude, was also important in accounting for community variability (4–23%); but to a lesser extent than the combined influence of climate and soil characteristics (14–25%). Results suggest that in situ climate can independently account for some patterns of microbial biogeography in coastal Douglas-fir forests. The distribution of up to 43% of nutrient-cycling microorganisms detected in forest soils responded to smaller abiotic gradients than host trees. PMID:26500636

  5. Vegetation/oceanographic changes in the mid-latitudes of southwestern North Atlantic during the Holocene

    NASA Astrophysics Data System (ADS)

    Naughton, Filipa; Keigwin, Lloyd; Oliveira, Dulce; Desprat, Stephanie; Abrantes, Fatima

    2013-04-01

    The direct correlation between terrestrial (pollen) and marine (planktonic δ18O) proxies from a slope core (KNR 178-2 JPC 32), retrieved in the Cape Hatteras (35°58.58'N, 74°42.77'W, 1006 m), provide substantial information on the Eastern North American vegetation response to the Holocene climate and oceanographic changes of the western North Atlantic. The end of the last glacial-interglacial transition is marked by the gradual replacement of the Boreal forest and herbs by temperate trees reflecting a general warming. Within this overall gradual warming, several abrupt vegetation shifts reveal episodes of relative cool and warm events. The most notorious continental warming of this transition, occurred at around 9650 cal yr BP and is synchronous with the increase of sea surface temperature as revealed by the planktonic foraminifera δ18O. The first maxima of temperate trees expansion, reflecting one of the most warmest events within the Holocene, occurred between 8700 and 7200 cal yr BP. Within this period 4 abrupt vegetation and hydrological changes suggest centennial scale returning cool conditions, being the most extreme detected at around 8400 cal yr BP. Between 7200 and 5300 cal yr BP temperate trees were partially replaced by hemlock suggesting a relative cool episode. The re-expansion of temperate trees marking a climatic warming is detected between 5300 and 2500 cal yr BP. Within this interval it is detected an important change in both vegetation and hydrology, marking a relative long lasting cooling between 4100 and 3550 cal yr BP. Finally the last 2500 cal yr BP is marked by important vegetation and hydrological shifts reflecting important climatic changes.

  6. Holocene Climatic Variability in the Cariboo Mountains, British Columbia, Based on Biogenic-silica Isotopes, Diatom Assemblages, Fire Frequency, and Vegetation Composition.

    NASA Astrophysics Data System (ADS)

    Gavin, D. G.; Henderson, A. C.; Hu, F.; Leng, M. J.; Westover, K.

    2005-12-01

    The mountains of east-central British Columbia have a climate with both maritime and continental influences, with precipitation distributed equally over the year. The vegetation history of this region indicates the establishment of forests with species with a mainly coastal distribution (i.e., cedar-hemlock `rainforests') at c. 4000 years BP, suggesting the increased importance of maritime climatic elements. We investigated the climatic changes associated with the development of this forest type using multiple climate proxies from the Blue River region, using a 7 m, 11,000-yr sediment record from Eleanor Lake (567'N; 19918'W; 860 m a.s.l.; max. depth 17 m). Chronological control is provided by 10 AMS radiocarbon dates, three tephra identifications, and 210Pb. The lake remained deep throughout the Holocene, as evidenced by diatom assemblages (planktonic and tychoplanktonic low salinity species) and mineralogy (pyrite). A high-resolution biogenic silica record shows high lake productivity before c. 6000 years BP, coincident with frequent fire and pine-dominated forests, indicating warm/dry summers. These proxies also show several instances of abrupt climatic change during this period. The record of oxygen isotopes from biogenic-silica (?18Odiat) (c. 75-year resolution) shows a millennial-scale trend with maximum values at 5000 years BP (c. 34 VSMOW), but there are also marked large-magnitude (c. 4) high frequency changes throughout the Holocene, including minimum values during a period coincident with the Little Ice Age. The trends in the ?18Odiat record suggest that oxygen-isotopes in this lake reflect changes in seasonality of both precipitation and temperature, as modern ?18O of lake water occur within the range of the local meteoric water line suggesting minimal evaporation. Our results show that sediment records from moist climatic regions, which lack carbonates, still may yield sensitive climatic reconstructions.

  7. Favorable fragmentation: river reservoirs can impede downstream expansion of riparian weeds.

    PubMed

    Rood, Stewart B; Braatne, Jeffrey H; Goater, Lori A

    2010-09-01

    River valleys represent biologically rich corridors characterized by natural disturbances that create moist and barren sites suitable for colonization by native riparian plants, and also by weeds. Dams and reservoirs interrupt the longitudinal corridors and we hypothesized that this could restrict downstream weed expansion. To consider this "reservoir impediment" hypothesis we assessed the occurrences and abundances of weeds along a 315-km river valley corridor that commenced with an unimpounded reach of the Snake River and extended through Brownlee, Oxbow, and Hells Canyon reservoirs and dams, and downstream along the Snake River. Sampling along 206 belt transects with 3610 quadrats revealed 16 noxious and four invasive weed species. Ten weeds were upland plants, with Canada thistle (Cirsium arvense) restricted to the upstream reaches, where field morning glory (Convolvulus arvensis) was also more common. In contrast, St. John's wort (Hypericum perforatum) was more abundant below the dams, and medusahead wildrye (Taeniatherum caput-medusae) occurred primarily along the reservoirs. All seven riparian species were abundant in the upstream zones but sparse or absent below the dams. This pattern was observed for the facultative riparian species, poison hemlock (Conium maculatum) and perennial pepperweed (Lepidium latifolium), the obligate riparian, yellow nut sedge (Cyperus esculentus), the invasive perennial, reed canary grass (Phalaris arundinacea), and three invasive riparian trees, Russian olive (Elaeagnus angustifolia), false indigo (Amorpha fruticosa), and tamarisk (Tamarix spp.). The hydrophyte purple loosestrife (Lythrum salicaria) was also restricted to the upstream zone. These longitudinal patterns indicate that the reservoirs have impeded the downstream expansion of riparian weeds, and this may especially result from the repetitive draw-down and refilling of Brownlee Reservoir that imposes a lethal combination of drought and flood stress. The dams and reservoirs may also interrupt hydrochory, the downstream flow of seeds and clonal fragments. We thus conclude that with some operational patterns, dams and reservoirs can impede the downstream expansion of riparian weeds. PMID:20945766

  8. Warm summer nights and the growth decline of shore pine in Southeast Alaska

    NASA Astrophysics Data System (ADS)

    Sullivan, Patrick F.; Mulvey, Robin L.; Brownlee, Annalis H.; Barrett, Tara M.; Pattison, Robert R.

    2015-12-01

    Shore pine, which is a subspecies of lodgepole pine, was a widespread and dominant tree species in Southeast Alaska during the early Holocene. At present, the distribution of shore pine in Alaska is restricted to coastal bogs and fens, likely by competition with Sitka spruce and Western hemlock. Monitoring of permanent plots as part of the United States Forest Service Forest Inventory and Analysis program identified a recent loss of shore pine biomass in Southeast Alaska. The apparent loss of shore pine is concerning, because its presence adds a vertical dimension to coastal wetlands, which are the richest plant communities of the coastal temperate rainforest in Alaska. In this study, we examined the shore pine tree-ring record from a newly established plot network throughout Southeast Alaska and explored climate-growth relationships. We found a steep decline in shore pine growth from the early 1960s to the present. Random Forest regression revealed a strong correlation between the decline in shore pine growth and the rise in growing season diurnal minimum air temperature. Warm summer nights, cool daytime temperatures and a reduced diurnal temperature range are associated with greater cloud cover in Southeast Alaska. This suite of conditions could lead to unfavorable tree carbon budgets (reduced daytime photosynthesis and greater nighttime respiration) and/or favor infection by foliar pathogens, such as Dothistroma needle blight, which has recently caused widespread tree mortality on lodgepole pine plantations in British Columbia. Further field study that includes experimental manipulation (e.g., fungicide application) will be necessary to identify the proximal cause(s) of the growth decline. In the meantime, we anticipate continuation of the shore pine growth decline in Southeast Alaska.

  9. Four Centuries of Change in Northeastern United States Forests

    PubMed Central

    Thompson, Jonathan R.; Carpenter, Dunbar N.; Cogbill, Charles V.; Foster, David R.

    2013-01-01

    The northeastern United States is a predominately-forested region that, like most of the eastern U.S., has undergone a 400-year history of intense logging, land clearance for agriculture, and natural reforestation. This setting affords the opportunity to address a major ecological question: How similar are today's forests to those existing prior to European colonization? Working throughout a nine-state region spanning Maine to Pennsylvania, we assembled a comprehensive database of archival land-survey records describing the forests at the time of European colonization. We compared these records to modern forest inventory data and described: (1) the magnitude and attributes of forest compositional change, (2) the geography of change, and (3) the relationships between change and environmental factors and historical land use. We found that with few exceptions, notably the American chestnut, the same taxa that made up the pre-colonial forest still comprise the forest today, despite ample opportunities for species invasion and loss. Nonetheless, there have been dramatic shifts in the relative abundance of forest taxa. The magnitude of change is spatially clustered at local scales (<125 km) but exhibits little evidence of regional-scale gradients. Compositional change is most strongly associated with the historical extent of agricultural clearing. Throughout the region, there has been a broad ecological shift away from late successional taxa, such as beech and hemlock, in favor of early- and mid-successional taxa, such as red maple and poplar. Additionally, the modern forest composition is more homogeneous and less coupled to local climatic controls. PMID:24023749

  10. Crown Features Extraction from Low Altitude AVIRIS Data

    NASA Astrophysics Data System (ADS)

    Ogunjemiyo, S. O.; Roberts, D.; Ustin, S.

    2005-12-01

    Automated tree recognition and crown delineations are computer-assisted procedures for identifying individual trees and segmenting their crown boundaries on digital imagery. The success of the procedures is dependent on the quality of the image data and the physiognomy of the stand as evidence by previous studies, which have all used data with spatial resolution less than 1 m and average crown diameter to pixel size ratio greater than 4. In this study we explored the prospect of identifying individual tree species and extracting crown features from low altitude AVIRIS (Airborne Visible/Infrared Imaging Spectrometer) data with spatial resolution of 4 m. The test site is a Douglas-fir and Western hemlock dominated old-growth conifer forest in the Pacific Northwest with average crown diameter of 12 m, which translates to a crown diameter pixel ratio less than 4 m; the lowest value ever used in similar studies. The analysis was carried out using AVIRIS reflectance imagery in the NIR band centered at 885 nm wavelength. The analysis required spatial filtering of the reflectance imagery followed by application of a tree identification algorithm based on maximum filter technique. For every identified tree location a crown polygon was delineated by applying crown segmentation algorithm. Each polygon boundary was characterized by a loop connecting pixels that were geometrically determined to define the crown boundary. Crown features were extracted based on the area covered by the polygons, and they include crown diameters, average distance between crowns, species spectral, pixel brightness at the identified tree locations, average brightness of pixels enclosed by the crown boundary and within crown variation in pixel brightness. Comparison of the results with ground reference data showed a high correlation between the two datasets and highlights the potential of low altitude AVIRIS data to provide the means to improve forest management and practices and estimates of critical plant-variables that are required by major components of ecosystem and climate models.

  11. Xiphinema bernardi n. sp. (Nematoda: Longidoridae) from the Great Smoky Mountain National Park

    PubMed Central

    Bae, Chang-Hwan; Ye, Weimin; Pedram, Majid

    2009-01-01

    In October 1985 during a survey of fauna of the Great Smoky Mountains National Park, Ernest Bernard recovered a limited number of specimens of a non-described species of Xiphinema (Nematoda: Longidoridae) and sent them to the senior author. The species is distinct from other species by its large size and having Z-organs in the genital tract. During July 2006, Dr. Bernard's survey crew took samples in the area where the species was first found and was successful in finding it again. Without Dr. Bernard's efforts, this species could not have been described and thus the new species is named X. bernardi n. sp. in his honor. Several female and juvenile specimens of the new species were recovered in a sample from a mixed forest of maple, hemlock, and silverbell. It is distinct from all others in Xiphinema group 4 species (with Z-organs) by having a longer total stylet length, 259.8 to 284.2 μm vs < 253 μm for all other species in this group. Xiphinema bernardi n. sp. is distinctive because of its long body length (4.45 to 6.00 mm), tail shape, and c' ratio. Of the group 4 species, it most closely resembles X. phoenicis. Second, third and fourth stage juvenile descriptions and morphometrics are included. The polytomous key code for X. bernardi n. sp. is A4-B1-C6-D56-E56-F(4)5-G4-H2-I34-J5-K?-L1. Molecular approaches using the internal transcribed spacer 1 sequences of nuclear ribosomal DNA suggested that X. bakeri and X. diversicaudatum are the most closely related species from the species examined. PMID:22661783

  12. Wood decomposition: Nitrogen and phosphorus dynamics in relation to extracellular enzyme activity

    SciTech Connect

    Sinsabaugh, R.L.; Antibus, R.K.; Linkins, A.E.; McClaugherty, C.A.; Rayburn, L.; Repert, D.; Weiland, T. )

    1993-07-01

    Because plant litter decomposition is directly mediated by extracellular enzymes (ectoenzymes), analyses of the dynamics of their activity may clarify the mechanisms that link decomposition rates to substrate quality and nutrient availability. For 3 yr, sites on a forested watershed samples were analyzed for mass loss, protein, total Kjeldahl nitrogen (TKN), and total phosphorus (TP) accumulation, and the activity of extracellular enzymes involved in C, N, and P cycling. The relationship between lignocellulase activity and mass loss did not differ among sites. TKN and TP immobilization exhibited some spatial variation. The relationship between the activities of acid phosphatase (AcPase) and N-acetylglucosaminidase (NAGase), and mass loss displayed even greater variation among sites, suggesting that edaphic rather than substrate quality factors were regulating activity. The extent of N limitation at each site was inferred by plotting TKN accumulation vs. mass loss, in relation to NAGase activity accumulation. P limitation at each site was similarly assessed from an analogous plot of TP accumulation in relation AcPase activity accumulation. Low N or P accumulation in conjunction with high acquisition activity was taken as an indication of nutrient limitation while the converse indicated surfeit. The diagrams suggested that decomposition at the upland hemlock and lotic sites was primarily N limited, while the riparian sites, which had the lowest rates of OM loss , appeared to be P limited. OM loss at the upland deciduous sites ( k = 0.38 g/mo) was not limited by either N or P. Field observations suggest that enzyme activity assays in conjunction with nutrient concentration measurements may be a useful indicator of nutrient limitation. An economic model is proposed that directly links N and P availability to litter decomposition rates on the basis of microbial allocation of resources to extracellular enzyme production. 25 refs., 4 figs., 4 tabs.

  13. Rapid in situ detection of alkaloids in plant tissue under ambient conditions using desorption electrospray ionization.

    PubMed

    Talaty, Nari; Takáts, Zoltán; Cooks, R Graham

    2005-12-01

    Desorption electrospray ionization (DESI) mass spectrometry is applied to the in situ detection of alkaloids in the tissue of poison hemlock (Conium maculatum), jimsonweed (Datura stramonium) and deadly nightshade (Atropa belladonna). The experiment is carried out by electrospraying micro-droplets of solvent onto native or freshly-cut plant tissue surfaces. No sample preparation is required and the mass spectra are recorded under ambient conditions, in times of a few seconds. The impact of the sprayed droplets on the surface produces gaseous ions from organic compounds originally present in the plant tissue. The effects of operating parameters, including the electrospray high voltage, heated capillary temperature, the solvent infusion rate and the carrier gas pressure on analytical performance are evaluated and optimized. Different types of plant material are analyzed including seeds, stems, leaves, roots and flowers. All the previously reported alkaloids have been detected in C. maculatum, while fifteen out of nineteen known alkaloids for D. stramonium and the principal alkaloids of A. belladonna were also identified. All identifications were confirmed by tandem mass spectrometry. Results obtained show similar mass spectra, number of alkaloids, and signal intensities to those obtained when extraction and separation processes are performed prior to mass spectrometric analysis. Evidence is provided that DESI ionization occurs by both a gas-phase ionization process and by a droplet pick-up mechanism. Quantitative precision of DESI is compared with conventional electrospray ionization mass spectrometry (after sample workup) and the RSD values for the same set of 25 dicotyledonous C. maculatum seeds (one half of each seed analyzed by ESI and the other by DESI) are 9.8% and 5.2%, respectively. PMID:16284661

  14. 14,000 Years of Sediment, Vegetation, and Water-Level Changes at the Makepeace Cedar Swamp, Southeastern Massachusetts

    NASA Astrophysics Data System (ADS)

    Newby, Paige E.; Killoran, Peter; Waldorf, Mahlon R.; Shuman, Bryan N.; Webb, Robert S.; Webb, Thompson

    2000-05-01

    Data from a transect of four cores collected in the Makepeace Cedar Swamp, near Carver, Massachusetts, record past changes in deposition, vegetation, and water level. Time series of palynological data provide a 14,000-yr record of regional and local vegetation development, a means for biostratigraphic correlation and dating, and information about changes in water level. Differences in records among cores in the basin show that water level decreased at least 1.5 m between ˜10,800 and 9700 cal yr B.P., after which sediment accumulation was slow and intermittent across the basin for about 1700 yr. Between 8000 and 5600 cal yr B.P., water level rose ˜2.0 m, after which slow peat accumulation indicates a low stand about the time of the hemlock decline at 5300 ± 200 cal yr B.P. Dry conditions may have continued after this time, but by 3200 cal yr B.P., the onset of peat accumulation in shallow cores indicates that water level had risen to close to its highest postglacial level, where it is today. Peat has accumulated across the whole basin since 3200 cal yr B.P. Data from Makepeace and the Pequot Cedar Swamp, near Ledyard, Connecticut, indicate an early Holocene dry interval in southern New England that began 11,500 yr ago near the end of the Younger Dryas interval. The dry conditions prevailed between 10,800 and 8000 cal yr B.P. and coincide with the arrival and later rise to dominance of white pine trees ( Pinus strobus) both regionally and near the basins. Our results indicate a climatic cause for the "pine period" in New England.

  15. Tradeoffs between chilling and forcing in satisfying dormancy requirements for Pacific Northwest tree species

    PubMed Central

    Harrington, Constance A.; Gould, Peter J.

    2015-01-01

    Many temperate and boreal tree species have a chilling requirement, that is, they need to experience cold temperatures during fall and winter to burst bud normally in the spring. Results from trials with 11 Pacific Northwest tree species are consistent with the concept that plants can accumulate both chilling and forcing units simultaneously during the dormant season and they exhibit a tradeoff between amount of forcing and chilling. That is, the parallel model of chilling and forcing was effective in predicting budburst and well chilled plants require less forcing for bud burst than plants which have received less chilling. Genotypes differed in the shape of the possibility line which describes the quantitative tradeoff between chilling and forcing units. Plants which have an obligate chilling requirement (Douglas-fir, western hemlock, western larch, pines, and true firs) and received no or very low levels of chilling did not burst bud normally even with long photoperiods. Pacific madrone and western redcedar benefited from chilling in terms of requiring less forcing to promote bud burst but many plants burst bud normally without chilling. Equations predicting budburst were developed for each species in our trials for a portion of western North America under current climatic conditions and for 2080. Mean winter temperature was predicted to increase 3.2–5.5°C and this change resulted in earlier predicted budburst for Douglas-fir throughout much of our study area (up to 74 days earlier) but later budburst in some southern portions of its current range (up to 48 days later) as insufficient chilling is predicted to occur. Other species all had earlier predicted dates of budburst by 2080 than currently. Recent warming trends have resulted in earlier budburst for some woody plant species; however, the substantial winter warming predicted by some climate models will reduce future chilling in some locations such that budburst will not consistently occur earlier. PMID:25784922

  16. Education and distance learning: changing the trends.

    PubMed

    Merrell, Ronald C

    2004-01-01

    Training and instruction are activities deeply ingrained in human relations and derive from the critical need for the young to learn survival skills. The responsibility in primitive society for such training almost certainly fell to parents who continued their pedagogical role after childhood issues to include hunting, gathering, fine motor activities and other life skills needed for personal or family survival. Such instruction only ended when the young were ready for independent life and- contribution to tribal well-being. Delegation of teaching to others was inevitable. Teaching has become a specialty and has at least one interesting story in ancient literature. Ulysses was certain to be away at the Trojan War and subsequent adventures for many years. He would not be able to provide his son, Telemachus, with the guidance and training to prepare him for adulthood. Therefore, he asked Mentor to act In Loco Parentis and instruct the young man toward competence and adult success. Teaching as a profession and discipline has been through many stages and many controversies. Socrates was a great teacher with a distinct technique for learning by questioning. His influence on his students was profound. Plato was such a good student he recorded all the master's works. Socrates has never been credited with even the briefest lecture note. As great as he was Socrates was forced to drink the bitter hemlock because his teaching was considered a corruption of youth rather than a proper preparation for effective adulthood. Dissonance between the expectations of learners, parents and teachers has a rich history. Certainly even now education is not something the professoriate may invent for the naïve learner and then expect grateful acquiesce with faithful learning. Learning has -dimensions in human psychology and communication. The learners' autonomy, privacy and motivation cannot be denied. Learning is collaboration with teacher and the endpoint is the acquisition of new knowledge or skill. PMID:15747972

  17. Wind River Watershed Restoration Project; Underwood Conservation District, Annual Report 2002-2003.

    SciTech Connect

    White, Jim

    2004-02-01

    The goal of the Wind River project is to preserve, protect and restore Wind River steelhead. In March, 1998, the National Marine Fisheries Service listed the steelhead of the lower Columbia as 'threatened' under the Endangered Species Act. In 1997, the Washington Department of Fish and Wildlife rated the status of the Wind River summer run steelhead as critical. Due to the status of this stock, the Wind River summer steelhead have the highest priority for recovery and restoration in the state of Washington's Lower Columbia Steelhead Conservation Initiative. The Wind River Project includes four cooperating agencies. Those are the Underwood Conservation District (UCD), United States Geological Service (USGS), US Forest Service (USFS), and Washington State Department of Fish & Wildlife (WDFW). Tasks include monitoring steelhead populations (USGS and WDFW), Coordinating a Watershed Committee and Technical Advisory Group (UCD), evaluating physical habitat conditions (USFS and UCD), assessing watershed health (all), reducing road sediments sources (USFS), rehabilitating riparian corridors, floodplains, and channel geometry (UCD, USFS), evaluate removal of Hemlock Dam (USFS), and promote local watershed stewardship (UCD, USFS). UCD's major efforts have included coordination of the Wind River Watershed Committee and Technical Advisory Committee (TAC), water temperature and water chemistry monitoring, riparian habitat improvement projects, and educational activities. Our coordination work enables the local Watershed Committee and TAC to function and provide essential input to Agencies, and our habitat improvement work focuses on riparian revegetation. Water chemistry and temperature data collection provide information for monitoring watershed conditions and fish habitat, and are comparable with data gathered in previous years. Water chemistry information collected on Trout Creek should, with 2 years data, determine whether pH levels make conditions favorable for a fish parasite, Heteropolaria lwoffi. Educational activities further the likelihood that future generations will continue to understand and enjoy the presence of native fish stocks in the Wind River basin.

  18. Comparison of nicotinic receptor binding and biotransformation of coniine in the rat and chick.

    PubMed

    Forsyth, C S; Speth, R C; Wecker, L; Galey, F D; Frank, A A

    1996-12-31

    Coniine, an alkaloid from Conium maculatum (poison hemlock), is a known teratogen in many domestic species with maternal ingestion resulting in arthrogryposis of the offspring. We have previously shown that rats are not susceptible and rabbits only weakly susceptible to coniine-induced arthrogryposis. However, the chick embryo does provide a reproducible laboratory animal model of coniine-induced teratogenesis. The reason for this cross-species variation is unknown. The purpose of this study was to evaluate coniine binding to nicotinic receptors and to measure coniine metabolism in vitro between susceptible and non-susceptible species. Using the chick model, neither the peripheral nicotinic receptor antagonist d-tubocurarine chloride nor the central nicotinic receptor antagonist trimethaphan camsylate blocked the teratogenesis or lethality of 1.5% coniine (50 microliters/egg). Trimethaphan camsylate enhanced coniine-induced lethality in a dose-dependent manner. Neither nicotinic receptor blocker prevented nicotine sulfate-induced malformations but d-tubocurarine chloride did block lethality in a dose-dependent manner. Competition by coniine for [125I]-alpha-bungarotoxin to nicotinic receptors isolated from adult rat diaphragm and chick thigh muscle and competition by coniine for [3H]-cytisine to receptors from rat and chick brain were used to assess coniine binding to nicotinic receptors. The IC50 for coniine in rat diaphragm was 314 microM while that for chick leg muscle was 70 microM. For neuronal nicotinic receptors, the IC50s of coniine for maternal rat brain, fetal rat brain, and chick brain were 1100 microM, 820 microM, and 270 microM, respectively. There were no differences in coniine biotransformation in vitro by microsomes from rat or chick livers. Differences in apparent affinity of coniine for nicotinic receptors or differences in the quantity of the nicotinic receptor between the rat and chick may explain, in part, the differences in susceptibility of coniine-induced teratogenesis between these two species. PMID:9001585

  19. Nutrient-cycling microbes in coastal Douglas-fir forests: regional-scale correlation between communities, in situ climate, and other factors.

    PubMed

    Shay, Philip-Edouard; Winder, Richard S; Trofymow, J A

    2015-01-01

    Microbes such as fungi and bacteria play fundamental roles in litter-decay and nutrient-cycling; however, their communities may respond differently than plants to climate change. The structure (diversity, richness, and evenness) and composition of microbial communities in climate transects of mature Douglas-fir stands of coastal British Columbia rainshadow forests was analyzed, in order to assess in situ variability due to different temperature and moisture regimes. We compared denaturing gradient gel electrophoresis profiles of fungi (18S-FF390/FR1), nitrogen-fixing bacteria (NifH-universal) and ammonia-oxidizing bacteria (AmoA) polymerase chain reaction amplicons in forest floor and mineral soil samples from three transects located at different latitudes, each transect spanning the Coastal Western Hemlock and Douglas-fir biogeoclimatic zones. Composition of microbial communities in both soil layers was related to degree days above 0°C (2725-3489), while pH (3.8-5.5) best explained shifts in community structure. At this spatial scale, climatic conditions were likely to directly or indirectly select for different microbial species while local site heterogeneity influenced community structure. Significant changes in microbial community composition and structure were related to differences as small as 2.47% and 2.55°C in mean annual moisture and temperature variables, respectively. The climatic variables best describing microbial composition changed from one functional group to the next; in general they did not alter community structure. Spatial distance, especially associated with latitude, was also important in accounting for community variability (4-23%); but to a lesser extent than the combined influence of climate and soil characteristics (14-25%). Results suggest that in situ climate can independently account for some patterns of microbial biogeography in coastal Douglas-fir forests. The distribution of up to 43% of nutrient-cycling microorganisms detected in forest soils responded to smaller abiotic gradients than host trees. PMID:26500636

  20. GIS interpolations of witness tree records (1839-1866) for northern Wisconsin at multiple scales

    USGS Publications Warehouse

    He, H.S.; Mladenoff, D.J.; Sickley, T.A.; Guntenspergen, G.R.

    2000-01-01

    To construct forest landscape of pre-European settlement periods, we developed a GIS interpolation approach to convert witness tree records of the U.S. General Land Office (GLO) survey from point to polygon data, which better described continuously distributed vegetation. The witness tree records (1839-1866) were processed for a 3-million ha landscape in northern Wisconsin, U.S.A. at different scales. We provided implications of processing results at each scale. Compared with traditional GLO mapping that has fixed mapping scales and generalized classifications, our approach allows presettlement forest landscapes to be analysed at the individual species level and reconstructed under various classifications. We calculated vegetation indices including relative density, dominance, and importance value for each species, and quantitatively described the possible outcomes when GLO records are analysed at three different scales (resolution). The 1 x 1-section resolution preserved spatial information but derived the most conservative estimates of species distributions measured in percentage area, which increased at coarser resolutions. Such increases under the 2 x 2-section resolution were in the order of three to four times for the least common species, two to three times for the medium to most common species, and one to two times for the most common or highly contagious species. We marred the distributions of hemlock and sugar maple from the pre-European settlement period based on their witness tree locations and reconstructed presettlement forest landscapes based on species importance values derived for all species. The results provide a unique basis to further study land cover changes occurring after European settlement.

  1. Kootenai River Fisheries Investigations; Rainbow and Bull Trout Recruitment, 1999 Annual Report.

    SciTech Connect

    Walters, Jody P.; Downs, Christopher C.

    2001-08-01

    Our 1999 objectives were to determine sources of rainbow trout Oncorhynchus mykiss and bull trout Salvelinus confluentus spawning and recruitment in the Idaho reach of the Kootenai River. We used a rotary-screw trap to capture juvenile trout to determine age at out-migration and to estimate total out-migration from the Boundary Creek drainage to the Kootenai River. The out-migrant estimate for March through August 1999 was 1,574 (95% C. I. = 825-3,283) juvenile rainbow trout. Most juveniles out-migrated at age-2 and age-3. No out-migrating bull trout were caught. Five of 17 rainbow trout radio-tagged in Idaho migrated upstream into Montana waters during the spawning season. Five bull trout originally radio-tagged in O'Brien Creek, Montana in early October moved downstream into Idaho and British Columbia by mid-October. Annual angler exploitation for the rainbow trout population upstream of Bonners Ferry, Idaho was estimated to be 58%. Multi-pass depletion estimates for index reaches of Caboose, Curley, and Debt creeks showed 0.20, 0.01, and 0.13 rainbow trout juveniles/m{sup 2}, respectively. We estimated rainbow trout (180-415 mm TL) standing stock of 1.6 kg/ha for the Hemlock Bar reach (29.4 ha) of the Kootenai River, similar to the 1998 estimate. Recruitment of juvenile rainbow and bull trout from Idaho tributaries is not sufficient to be the sole source of subsequent older fish in the mainstem Kootenai River. These populations are at least partly dependent on recruitment from Montana waters. The low recruitment and high exploitation rate may be indicators of a rainbow trout population in danger of further decline.

  2. Potential role of natural enemies during tree range expansions following climate change.

    PubMed

    Moorcroft, P R; Pacala, S W; Lewis, M A

    2006-08-01

    Recent investigations have shown how chance, long-range dispersal events can allow tree populations to migrate rapidly in response to changes in climate. However, this apparent solution to Reid's paradox applies solely within the context of single species models, while the rapid migration rates seen in pollen records occurred within multispecies communities. Ecologists are therefore presented with a new challenge: reconciling the macroscopic dynamics of spread seen in the pollen record with the rules and interactions governing plant community assembly. A case that highlights this issue is the rapid spread of Beech during the Holocene into a landscape already dominated by a close competitor, Hemlock. In this study, we analyse a simple model of plant community assembly incorporating competition for space and dispersal dynamics, showing how, even when a species is capable of rapid migration into an empty landscape, the presence of an ecologically similar competitor causes Reid's paradox to re-emerge because of the dramatic slowing effect of competitive interactions on a species' rate of spread. We then show how the answer to the question of how tree species dispersed rapidly into occupied landscapes may lie in secondary interactions with host-specific pathogens and parasites. Inclusion of host-specific pathogens into the simple community assembly model illustrates how tree species undergoing range expansions can temporarily outstrip specialist predators, giving rise to a transient Jansen-Connell effect, in which the invader acts as temporary 'super-species' that spreads rapidly into communities already occupied by competitors at rates consistent with those observed in the paleo-record. PMID:16499931

  3. Tradeoffs between chilling and forcing in satisfying dormancy requirements for Pacific Northwest tree species.

    PubMed

    Harrington, Constance A; Gould, Peter J

    2015-01-01

    Many temperate and boreal tree species have a chilling requirement, that is, they need to experience cold temperatures during fall and winter to burst bud normally in the spring. Results from trials with 11 Pacific Northwest tree species are consistent with the concept that plants can accumulate both chilling and forcing units simultaneously during the dormant season and they exhibit a tradeoff between amount of forcing and chilling. That is, the parallel model of chilling and forcing was effective in predicting budburst and well chilled plants require less forcing for bud burst than plants which have received less chilling. Genotypes differed in the shape of the possibility line which describes the quantitative tradeoff between chilling and forcing units. Plants which have an obligate chilling requirement (Douglas-fir, western hemlock, western larch, pines, and true firs) and received no or very low levels of chilling did not burst bud normally even with long photoperiods. Pacific madrone and western redcedar benefited from chilling in terms of requiring less forcing to promote bud burst but many plants burst bud normally without chilling. Equations predicting budburst were developed for each species in our trials for a portion of western North America under current climatic conditions and for 2080. Mean winter temperature was predicted to increase 3.2-5.5°C and this change resulted in earlier predicted budburst for Douglas-fir throughout much of our study area (up to 74 days earlier) but later budburst in some southern portions of its current range (up to 48 days later) as insufficient chilling is predicted to occur. Other species all had earlier predicted dates of budburst by 2080 than currently. Recent warming trends have resulted in earlier budburst for some woody plant species; however, the substantial winter warming predicted by some climate models will reduce future chilling in some locations such that budburst will not consistently occur earlier. PMID:25784922

  4. Soil greenhouse gas fluxes from different tree species on Taihang Mountain, North China

    NASA Astrophysics Data System (ADS)

    Liu, X. P.; Zhang, W. J.; Hu, C. S.; Tang, X. G.

    2014-03-01

    The objectives of this study were to investigate seasonal variation of greenhouse gas fluxes from soils on sites dominated by plantation (Robinia pseudoacacia, Punica granatum, and Ziziphus jujube) and natural regenerated forests (Vitex negundo var. heterophylla, Leptodermis oblonga, and Bothriochloa ischcemum), and to identify how tree species, litter exclusion, and soil properties (soil temperature, soil moisture, soil organic carbon, total N, soil bulk density, and soil pH) explained the temporal and spatial variation in soil greenhouse gas fluxes. Fluxes of greenhouse gases were measured using static chamber and gas chromatography techniques. Six static chambers were randomly installed in each tree species. Three chambers were randomly designated to measure the impacts of surface litter exclusion, and the remaining three were used as a control. Field measurements were conducted biweekly from May 2010 to April 2012. Soil CO2 emissions from all tree species were significantly affected by soil temperature, soil moisture, and their interaction. Driven by the seasonality of temperature and precipitation, soil CO2 emissions demonstrated a clear seasonal pattern, with fluxes significantly higher during the rainy season than during the dry season. Soil CH4 and N2O fluxes were not significantly correlated with soil temperature, soil moisture, or their interaction, and no significant seasonal differences were detected. Soil organic carbon and total N were significantly positively correlated with CO2 and N2O fluxes. Soil bulk density was significantly negatively correlated with CO2 and N2O fluxes. Soil pH was not correlated with CO2 and N2O emissions. Soil CH4 fluxes did not display pronounced dependency on soil organic carbon, total N, soil bulk density, and soil pH. Removal of surface litter significantly decreased in CO2 emissions and CH4 uptakes. Soils in six tree species acted as sinks for atmospheric CH4. With the exception of Ziziphus jujube, soils in all tree species acted as sinks for atmospheric N2O. Tree species had a significant effect on CO2 and N2O releases but not on CH4 uptake. The lower net global warming potential in natural regenerated vegetation suggested that natural regenerated vegetation were more desirable plant species in reducing global warming.

  5. Winter Soil CO2 Flux from Different Mid-Latitude Sites from Middle Taihang Mountain in North China

    PubMed Central

    Zhang, Wanjun; Zeng, Xinhua; Wang, Huaru

    2014-01-01

    Winter soil respiration is a very important component of the annual soil carbon flux in some ecosystems. We hypothesized that, with all other factors being equal, shorter winter SR result in reduced contribution to annual soil C flux. In this study, the contribution of winter soil respiration to annual soil respiration was measured for three sites (grassland: dominated by Artemisia sacrorum, Bothriochloa ischaemum and Themeda japonica; shrubland: dominated by Vitex negundo var. heterophylla; plantation: dominated by Populus tomatosa) in a mountainous area of north China. Diurnal and intra-annual soil CO2 flux patterns were consistent among different sites, with the maximum soil respiration rates at 12∶00 or 14∶00, and in July or August. The lowest respiration rates were seen in February. Mean soil respiration rates ranged from 0.26 to 0.45 µmol m−2 s−1 in the winter (December to February), and between 2.38 to 3.16 µmol m−2 s−1 during the growing season (May-September). The winter soil carbon flux was 24.6 to 42.8 g C m−2, which contributed 4.8 to 7.1% of the annual soil carbon flux. Based on exponential functions, soil temperature explained 73.8 to 91.8% of the within year variability in soil respiration rates. The Q10 values of SR against ST at 10 cm ranged from 3.60 to 4.90 among different sites. In addition, the equation between soil respiration and soil temperature for the growing season was used to calculate the “modeled” annual soil carbon flux based on the actual measured soil temperature. The “measured” annual value was significantly higher than the “modeled” annual value. Our results suggest that winter soil respiration plays a significant role in annual soil carbon balance, and should not be neglected when soil ecosystems are assessed as either sinks or sources of atmospheric CO2. PMID:24614868

  6. Impacts of an exotic disease and vegetation change on foliar calcium cycling in Appalachian forests.

    PubMed

    Jenkins, Michael A; Jose, Shibu; White, Peter S

    2007-04-01

    Because of the high calcium content of its foliage, Cornus florida (flowering dogwood) has been described as a calcium "pump" that draws calcium from deeper mineral soil and enriches surface soil horizons. However, over the last two decades an exotic fungal disease (dogwood anthracnose, Discula destructiva) has decimated populations of this once-common understory species. Its loss, combined with forest stand development, could alter intra-stand calcium cycling. We used data from long-term vegetation monitoring plots to examine the ecological role of C. florida in calcium cycling and to identify changes in annual foliar calcium cycling over a 20-year period between two sampling intervals, 1977-1979 (preanthracnose) and 1995-2000 (post-anthracnose). Published equations were used to estimate foliar biomass per species for five forest types: alluvial, typic cove, acid cove, oak-hickory, and oak-pine. Calcium concentrations derived from foliage samples were used to estimate annual foliar calcium production per species for understory woody stems (<20 cm dbh) and total foliar calcium production for overstory stems (> or =20 cm dbh). At a given level of soil calcium availability, C. florida foliage contained greater concentrations of calcium than three other dominant understory species (Tsuga canadensis, Acer rubrum, and Rhododendron maximum). Between 1977-1979 and 1995-2000, the annual calcium contributions of understory woody vegetation declined across all forest types, ranging from 26% in oak-pine stands to 49% in acid coves. Loss of C. florida was responsible for only 13% of this decline in oak-pine stands, but accounted for 96% of the decline in typic coves. In oak-hickory and oak-pine stands, we observed large increases in the foliar biomass of T. canadensis, a species whose calcium-poor foliage increases soil acidity. Increases in overstory foliar biomass and calcium offset understory losses in three forest types (alluvial, typic coves, and oak-pine) but not in oak-hickory and acid cove stands. Overall, calcium cycling in oak-hickory stands was more negatively affected by the loss of C. florida than the other forest types. Oak-hickory forests comprise over a third of the total forest cover in the eastern United States, and decreases in annual calcium cycling could have cascading effects on forest biota. PMID:17494403

  7. Twentieth-century decline of large-diameter trees in Yosemite National Park, California, USA

    USGS Publications Warehouse

    Lutz, J.A.; van Wagtendonk, J.W.; Franklin, J.F.

    2009-01-01

    Studies of forest change in western North America often focus on increased densities of small-diameter trees rather than on changes in the large tree component. Large trees generally have lower rates of mortality than small trees and are more resilient to climate change, but these assumptions have rarely been examined in long-term studies. We combined data from 655 historical (1932-1936) and 210 modern (1988-1999) vegetation plots to examine changes in density of large-diameter trees in Yosemite National Park (3027 km2). We tested the assumption of stability for large-diameter trees, as both individual species and communities of large-diameter trees. Between the 1930s and 1990s, large-diameter tree density in Yosemite declined 24%. Although the decrease was apparent in all forest types, declines were greatest in subalpine and upper montane forests (57.0% of park area), and least in lower montane forests (15.3% of park area). Large-diameter tree densities of 11 species declined while only 3 species increased. Four general patterns emerged: (1) Pinus albicaulis, Quercus chrysolepis, and Quercus kelloggii had increases in density of large-diameter trees occur throughout their ranges; (2) Pinus jeffreyi, Pinus lambertiana, and Pinus ponderosa, had disproportionately larger decreases in large-diameter tree densities in lower-elevation portions of their ranges; (3) Abies concolor and Pinus contorta, had approximately uniform decreases in large-diameter trees throughout their elevational ranges; and (4) Abies magnifica, Calocedrus decurrens, Juniperus occidentalis, Pinus monticola, Pseudotsuga menziesii, and Tsuga mertensiana displayed little or no change in large-diameter tree densities. In Pinus ponderosa-Calocedrus decurrens forests, modern large-diameter tree densities were equivalent whether or not plots had burned since 1936. However, in unburned plots, the large-diameter trees were predominantly A. concolor, C. decurrens, and Q. chrysolepis, whereas P. ponderosa dominated the large-diameter component of burned plots. Densities of large-diameter P. ponderosa were 8.1 trees ha-1 in plots that had experienced fire, but only 0.5 trees ha-1 in plots that remained unburned. ?? 2009 Elsevier B.V. All rights reserved.

  8. Impacts of traditional land use practices on soil organic carbon and nitrogen pools of mountain ecosystems in Nepal

    NASA Astrophysics Data System (ADS)

    Giri, Anjana; Katzensteiner, Klaus

    2010-05-01

    Crop production, animal husbandry and forestry are three closely interlinked components of land use systems in the mountains of Nepal. Forests are the major source of fuel wood, construction materials, fodder and litter. The latter is used as a bedding material for livestock and forms an important component of farmyard manure. In addition forest grazing by cattle is a common practice. Excessive extraction of biomass from the forest leads to a decline of soil organic matter and nutrient contents. On the landscape scale these negative effects will partly be compensated by positive effects on soil organic matter and nutrient stocks of arable soils. The experimental data base for a quantification of such effects at the scale of communities is however poor, in particular for Nepal. Understanding the impact of subsistence farming on ecosystems is imperative in order to recommend successful and sustainable land management practices. The aim of our study is to quantify effects of land use on carbon and nitrogen pools and fluxes for mountain communities in Nepal. Results of a case study in the buffer zone area of the Sagarmatha National Park are presented. The potential vegetation comprises mixed forests of Quercus semicarpifolia, Rhododendron arboreum and Tsuga dumosa. Carbon and nitrogen stocks in soil and vegetation were quantified for three different land use types, namely: forest with low human impact, forests with high human impact and agricultural land. The scale of disturbance of the forests has been classified by visual estimation considering the percentage of litter raked, number of lopped trees, and grazing intensity assessed by signs of trampling and the number of trails. After stratification of the community area, 20 plots of 10 m radius were established (17 forest plots, 3 plots for arable land) where biometric data of the vegetation were determined and sub-samples were taken for chemical analyses. Organic layers (litter remaining after litter raking) and soil samples were collected (volumetric sampling of geometric horizons down to 1 m depth). Fluxes of carbon and nitrogen from the forests were accounted by combining results of sub samples of biomass extracted by local people during the field survey and information on amounts and source areas provided by the farmers. Also the amount of carbon and nutrients applied with farmyard manure and the extraction by harvest was determined for the arable land. First estimates of carbon and nitrogen cycling at the community level and on impacts on soil status will be presented.

  9. Neogene vegetation and past climate change in the Thakkhola-Mustang Graben (central Nepal).

    NASA Astrophysics Data System (ADS)

    Adhikari, Basanta Raj; Wagreich, Michael; Draxler, Ilse; Paudayal, Khum N.

    2010-05-01

    The Thakkhola-Mustang Graben, which reflects Neogene extensional tectonics in the Tibetan Plateau and Himalaya, lies north of the Dhaulagiri-Annapurna ranges and south of the Yarlung-Tsangpo Suture Zone. The basement of Thakkhola-Mustang Graben is made up of Tibetan-Tethyan sedimentary rocks of Paleozoic and Mesozoic ages, which are unconformably overlain by continental debris (more than 850 m) of Neogene to Quaternary age. Stratigraphically, the Thakkhola-Mustang Graben sediments have been divided into five formations namely the Tetang Formation, the Thakkhola Formation, the Sammargaon Formation, the Marpha Formation and the Kaligandaki Formation. Different approaches have been made to study the Neogene sediments in this graben. In this study, we mainly focused on sedimentological and palynological studies of the Thakkhola-Mustang Graben, which provides a basis for discussing the paleo-environmental evolution of the southern continental margin of the Tibetan Plateau towards the end of the Miocene. Field mapping, profile logging, stable carbon and oxygen isotope analysis, and palynological studies were carried out to understand the depositional environment and the paleoclimate. The methodology developed by Zetter (1989) was followed for the pollen extraction. Pollen samples were processed in the laboratory and were studied under the light microscope (LM), which were later transferred to the scanning electron microscope (SEM). A variety of sedimentary environments are recognized including alluvial fan, lacustrine, braided river and glacio-fluvial. Neogene sediments are composed of braided fluvial deposits with lacustrine deposits in different level of the succession. Most of the pollens were found in the lacustrine layers of the Tetang and Thakkhola formations. Pollen analysis shows that the sediments contain dominant alpine trees like Abies, Pinus, Keteleeria, Picea Tsuga and Quercus with some steppe elements like Artemisia, Compositae, Chenopodiaceae, Plantago and Poaceae. The results show that during this period, the southern part of Tibet was covered mainly by steppe vegetation, indicating dry climate. Organic plant material from the Thakkhola and Tetang formations yielded stable carbon isotope (d13C) values between -21.87 to -26.64 permil, indicating the presence of C3 vegetation. However, the d13C values from the carbonates range between -0.62 to 11.08 permil, which shows the mix vegetation of C3 and C4 plants. It is presumed that the paleoclimate during the sediment deposition time of the Thakkhola-Mustang Graben was significantly warmer than the present-day climate. Further study of pollen with LM and SEM is necessary. Reference: Zetter, R., 1989, Methodik und Bedeutung einer routinemäßig kombinierten lichtmikroskopischen und rasterelektronenmikroskopischen Untersuchung fossiler Mikrofloren. Cour. Forsch.-Inst. Senckenberg, Frankfurt am Main, 109, 41-50.

  10. Last glacial pollen record from Lanzhou (Northwestern China) and possible forcing mechanisms for the MIS 3 climate change in Middle to East Asia

    NASA Astrophysics Data System (ADS)

    Jiang, Hanchao; Mao, Xue; Xu, Hongyan; Thompson, Jessica; Wang, Ping; Ma, Xiaolin

    2011-03-01

    The vegetation on the northeastern margin of the Tibetan Plateau is highly sensitive to climatic changes and thus represents a potentially interesting environmental archive. Pollen samples from the Fanjiaping Loess section in Lanzhou on the western Chinese Loess Plateau (CLP) were analyzed in conjunction with OSL dating. The results indicate that pollen zone B (60.6-46.0 ka, correlative to the early MIS 3) had the greatest abundances of Cupressaceae, Tsuga, Gramineae and Cyperaceae of the entire section, suggesting a warm phase during the last glacial period. These pollen taxa decreased significantly in abundance in the zones C (46.0-39.0 ka) and D (39.0-27.0 ka), reflecting a substantial climate cooling from the middle MIS 3 to MIS 2. These results correlate with climate records from the South China Sea, the CLP, Baikal Lake, North America, North Atlantic Ocean and other regions, and probably correspond with the decline of northern high-latitude insolation and the increase of global ice volume from 50 to 20 ka. In particular, arboreal pollen, fern spore and algae abundances declined sharply since ˜40 ka, while shrub and herb pollen reached the highest abundances. Conifer pollen Picea and Abies abundance also rose markedly and increased up the section. This implies significant climate deterioration and likely corresponded with substantial growth of the polar ice sheets since ˜40 ka. The decreasing temperature caused by an insolation decline during the last glacial period probably reinforced the cooling effect in a 'snow/ice/albedo' feedback, which would result in less climate sensitivity to radiative forcing. Meanwhile, vegetation decline in the Northern Hemisphere during the last glacial period and tundra development at high latitudes possibly caused additional cooling, enhancing the growth of polar ice sheets since 40 ka. The development of polar ice sheets increased the polar-to-equator temperature and pressure gradients, strengthening the westerlies and supplying plenty of moisture to Northwest China during 40-30 ka. Lake sediments developed widely on the Tibetan Plateau during 40-30 ka, probably related to an increase in the seasonality of middle-to-low latitude insolation which caused an enhancement of glacier melting on the Plateau.

  11. Late Miocene (Pannonian) Vegetation from the Northern Part of Central Paratethys

    NASA Astrophysics Data System (ADS)

    Kováčová, M.; Doláková, N.

    2009-04-01

    During Late Miocene, the Western Carpathian paleogeography started to change. The Lake Pannon retreated southwards, and the northern coast of the back arc basin was slightly elevated due to progradation of deltaic and alluvial facies, especially in the lowlands. The studied „Pannonian lake" sediments come from the Czech and Slovak parts of Central Paratethys. Changes of the sedimentary environment from deep to shallow lake and deltaic environment, followed by development of alluvial plains were noticed. Salinity crisis due to Paratethys isolation led to development of total freshwater environment to the end of this period. Samples from 3 surficial localities and 15 boreholes were palynologically studied. Occasional occurences of Dinoflagellates indicate a slightly higher salinity, whereas green algae Pediastrum, aquatic ferns Azolla, and aquatic and coastal plants (Nelumbo, Nymphaea, Myriophyllum, Sparganium, Potamogeton, Cyperaceae etc.) represent a freshwater environment. Due to paleogeographic changes and climatic oscillations the number of thermophilous taxa decreased and some of them disappeared completely from this area (f. e. Sapotaceae, Palmae). Mostly broad-leaved deciduous elements of mixed mesophytic forests (Quercus, Celtis, Carya, Tilia, Carpinus, Betula, Juglans) with some thermophilous elements admixture of Engelhardia, Castanea, Trigonobalanopsis, Symplocos, Cornaceaepollis satzveyensis generally dominate. Variously high relief of the uplifted mountainy chains created ideal conditions for higher presence of extrazonal vegetation (Cedrus, Tsuga, Picea, Cathaya) in the investigated area. Zonal type of vegetation including marshes, riparian forests with Alnus, Salix, Pterocarya, Liquidambar, Betula, Fraxinus, shrubs and lianas on dryer substrates associated riparian forest (Buxus, Ericaceae, Vitaceae, Lonicera, Rosaceae type Rubus), and coastal swamps with Taxodiaceae, Nyssa, Myrica, Sciadopitys were growing in the floodplain lowlands of Vienna Basin. Accumulations of the Chenopodiaceae in the interfluve areas probably indicate local saline swampy environments during sea level fall. The increasing amounts of herbs indicate the existence of wet prairie areas (Thalictrum, Rumex, Valeriana, Dipsacaceae, Lamiaceae, Galium) or steppes (Artemisia - up to 17%, Asteraceae, Campanula, Fabaceae, Daucaceae, Caryophyllaceae, Plantago). This is the contribution to the projects ESF -EC-009-07, APVT 51-011305, APVV-0280-07 (Slovakia) and MSM0021622427 (Czech republic).

  12. Stand age- and climate variability-effects on ecosystem exchange at the Wind River Experimental Forest, Washington, USA

    NASA Astrophysics Data System (ADS)

    Wharton, Sonia

    The conifer forests of the Pacific Northwest, USA have the highest levels of carbon sequestration in North America and the greatest potential for future carbon uptake of any terrestrial ecosystem. Any major changes to carbon uptake in these ecosystems will influence the North American CO2 budget despite the relatively small size (105 km2) of the Pacific Northwest forest biome. This dissertation is organized into three scientific papers which examine how year-to-year climate variability and clear-cut logging affect the carbon budgets of these forests. The forests include the Wind River AmeriFlux site, an old-growth Douglas-fir/western hemlock forest and two nearby young Douglas-fir forest stands. Carbon exchange is measured with the eddy covariance technique. In Paper 1, year-to-year variability in three Pacific Ocean teleconnection patterns (Pacific Decadal Oscillation, Pacific/North American Oscillation and El Nino-Southern Oscillation) are examined to determine if CO 2 and H2O fluxes at the old-growth forest are affected by climatic changes associated with these events. The largest ecosystem anomalies in net ecosystem production, gross primary production, respiration, light use efficiency and water use efficiency occurred when all three teleconnections were either in a negative or positive climate phase. Results from this paper suggest that any increases in the frequency of negative-phase Pacific teleconnection patterns will increase annual carbon sequestration in some Pacific Northwest forests. However, stronger and more frequent positive phases will likely decrease net carbon uptake. The influences of clear-cut logging on atmospheric-forest CO2 exchange are examined in Papers 2 and 3. Age-specific and seasonal-specific feedbacks between carbon and water exchange, radiation, canopy conductance, vapor pressure deficit and soil moisture were measured in the old-growth forest and two very recent clear-cuts (early seral forest stands). Early seral stands had lower net carbon uptake rates than mature stands and highest uptake occurred during different seasons. Peak net carbon uptake was measured in March-May at the old-growth forest but not until July-August at the younger stands. The results from these papers suggest that young Douglas-fir stands will be more susceptible than older forests to any increases in water stress if the Pacific Northwest summer drought becomes longer or more intense.

  13. [Can we speak of the management of pain under the Empire?].

    PubMed

    Le Dantec, Pierre

    2014-01-01

    It is essential first to disregard all our knowledge and current certainties to plunge two centuries behind. Pain is recognized: physical, moral, chronic, acute. The story of analgesia finds the use of poppy, but with equal components, in variable quantity, the analgesic potion could be transformed into a poison. In the 17th century Sydenham vulgarizes the use of the laudanum known since the 16th, and the first general anesthesia will take place in 1846, we can say that, under the Empire, we are in the prehistory of the anesthesia. The positioning of the doctors and the surgeons in front of the pain is ambiguous. The pain is lived as inevitable, the first quality of the surgeon is its operating speed which allows to limit the duration of the sufferings. The practitioners in the contact of the suffering are going to try hard to develop clevernesses and subtleties to decrease this daily pain. The physical ways as baths or showers, bloodletting in the inflammatory pains, plants with antispasmodic property (valerian, peony, hemlock) and other more or less trivial pharmacological ways. On the battlefield, the ways are even more rationalized and limited, first the pharmacological ways with the laudanum and the liqueur of Hoffmann, surgery which, by a violent but brief pain, solves the problem of the traumatic pains. Dominique Larrey notices the analgesic effects of the cold, but he does not seem to have voluntarily used it. Acute drunkenness is recognized as dangerous. We are struck by the number of description of violent suicides, in particular at the Hôtel National des Invalides. Just like physical pain, moral suffering is recognized as a disease, described as melancholy but without any practical or therapeutic consequence. Under the Empire, pain is taken care of, according to the criteria of the time, an inescapable fate of which it is necessary to adapt. The field doctors try hard to decrease the pain intensity, but the university medical elites exclude the idea to overcome it totally. Nevertheless, thirty years later, general anesthesia will become possible. PMID:25966535

  14. Meltwater discharge and the triggering of Younger Dryas : new data on the chronology of Champlain Sea transgression in the St-Lawrence River Valley

    NASA Astrophysics Data System (ADS)

    Richard, P.; Occhietti, S.

    2004-05-01

    Accurate chronology of ice retreat is crucial to understand the Ocean-Atmosphere couple at the end of the Pleistocene. The St-Lawrence River Valley is key in this regard, and two sedimentary sequences from Mount Saint-Hilaire, in the middle of the valley, contain a record that sheds new lignt on ice retreat and the penecontemporaneous proglacial marine invasion. Basal AMS-dates on terrestrial plant macrofossils coupled with an extrapolation from the pollen content of underlying postglacial lake sediments at Hemlock Carr (243 m), show that local ice retreat occurred around 11 350 14C yr BP. Cross-dating of such macrofossils (10 510 ± 60 14C yr BP) with shells from marine sediments (~12 200 14C yr BP) catched in the neighbouring Lake Hertel's basin (169 m) show a ca. 1700 14C years difference mainly ascribed to the effect of old, glacially-derived carbon in the upper shallow waters of the Champlain Sea. The pollen-based chronological extrapolation at Lake Hertel indicates that the marine invasion occurred around 11 100 ± 100 14C yr BP. This result supports the chronology based on deep-water invertebrate marine fauna (Rodrigues, 1988). The 14C assessment of the New-England varve chronology (Ridge et al., 1999) is thus confirmed. Deglaciation of the entire Saint-Lawrence River Valley took place within 1000 14C years. The chronology of ice retreat in southern Québec is shortened and made younger. This prompts major revision of all the associated paleohydrological events. Routing of the glacial meltwaters to the North Atlantic was impossible before 11 100 14C yr BP. The abrupt transition from Glacial Lake Candona (ca. 220 m) to the proglacial phase of the Champlain Sea (ca. 190 m) at 11 100 14C yr BP implies an input of glacial meltwater to the ocean estimated at 1500 km3. This may well have affected the thermohaline circulation in the North Atlantic and triggered the Younger Dryas oscillation.

  15. Leaf economics of evergreen and deciduous tree species along an elevational gradient in a subtropical mountain

    PubMed Central

    Bai, Kundong; He, Chengxin; Wan, Xianchong; Jiang, Debing

    2015-01-01

    The ecophysiological mechanisms underlying the pattern of bimodal elevational distribution of evergreen tree species remain incompletely understood. Here we used leaf economics spectrum (LES) theory to explain such patterns. We measured leaf economic traits and constructed an LES for the co-existing 19 evergreen and 15 deciduous species growing in evergreen broad-leaved forest at low elevation, beech-mixed forest at middle elevation and hemlock-mixed forest at high elevation in Mao'er Mountain, Guangxi, Southern China (25°50′N, 110°49′E). Leaf economic traits presented low but significant phylogenetic signal, suggesting trait similarity between closely related species. After considering the effects of phylogenetic history, deciduous species in general showed a more acquisitive leaf strategy with a higher ratio of leaf water to dry mass, higher leaf nitrogen and phosphorous contents, higher photosynthetic and respiratory rates and greater photosynthetic nitrogen-use efficiency. In contrast, evergreen species exhibited a more conservative leaf strategy with higher leaf mass per area, greater construction costs and longer leaf life span. With the elevation-induced decreases of temperature and soil fertility, both evergreen and deciduous species showed greater resource conservation, suggesting the increasing importance of environmental filtering to community assembly with increasing elevation. We found close inter-specific correlations between leaf economic traits, suggesting that there are strong genetic constraints limiting the independent evolution of LES traits. Phylogenetic signal increased with decreasing evolutionary rate across leaf economic traits, suggesting that genetic constraints are important for the process of trait evolution. We found a significantly positive relationship between primary axis species score (PASS) distance and phylogenetic distance across species pairs and an increasing average PASS distance between evergreen and deciduous species with increasing elevation, implying that the frequency of distantly related evergreen and deciduous pairs with wide spreading of leaf economic values increases with increasing elevation. Our findings thus suggest that elevation acts as an environmental filter to both select the locally adapted evergreen and deciduous species with sufficient phylogenetic variation and regulate their distribution along the elevational gradient based on their coordinated spreading of phylogenetic divergence and leaf economic variation. PMID:26056133

  16. Day-roosts of female long-eared myotis in Western Oregon

    USGS Publications Warehouse

    Waldien, David L.; Hayes, J.P.; Arnett, Edward B.

    2000-01-01

    Roosts are a critical habitat component for bats and may influence their survival and fitness. We used radiotelemetry to investigate characteristics of day-roosts of female long-eared myotis (Myotis evotis) in watersheds characterized by different forest conditions and the spatial relationships between day-roosts and available water. We tracked 21 bats to 73 roosts (n = 102 occasions) from June to August 1996 and 1997 on the western slope of the Cascade Mountains, Oregon. Bats primarily used conifer stumps as day-roosts in watersheds dominated by younger forests and used conifer snags, and to a lesser extent conifer stumps, in watersheds with greater proportions of older forests. Individual long-eared myotis used different types of structures as day-roosts, and type of structure used did not differ with reproductive condition. Day-roosts were primarily located in upslope habitat and averaged 0.59 A? 0.03 km from available water and 0.66 A? 0.02 km from capture sites. Roosts were not located closer to available water than random points, but were closer than random points to captures sites. Conifer snags used as day-roosts averaged 34 A? 5 m in height and 93 A? 12 cm diameter at breast height (dbh); snags in intermediate stages of decay had highest use. Use of conifer snags was positively associated with the number of snags within 20 m and negatively associated with distance from stand edge. Conifer stumps used as day-roosts averaged 133 A? 9 cm in height and 59 A? 4 cm dbh. Western hemlock and Douglas-fir stumps were used more often than western redcedar stumps as day-roosts. Odds of a stump being used as a day-roost increased with increasing height of the stump (downhill side) and whether it was situated in a gap in vegetation. We contend that management of day-roosts for forest-dwelling bats should focus on maintaining large conifer snags across landscapes through space and time. In landscapes where there are relatively few large conifer snags, stumps appear to provide important, but ephemeral, roosts for long-eared myotis.

  17. Stemflow amount, intensity and timing in a mature forest in coastal British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    van Meerveld, Ilja; Spencer, Sheena

    2013-04-01

    Stemflow is the portion of precipitation that falls on the forest canopy and flows along tree branches and stems to the soil at the base of the tree. Previous studies have shown the importance of stemflow for nutrient cycling, groundwater recharge, plant water uptake and soil moisture dynamics; however little is known about stemflow in mature coastal British Columbia forests. Furthermore, most studies focus on the amount of stemflow; few studies have looked at the timing or intensity of stemflow relative to precipitation intensity. We therefore measured stemflow from 18 trees of four different species within a ~1 ha mature western hemlock-western redcedar stand within the Malcolm Knapp Research Forest in British Columbia, Canada, using water collecting containers and tipping bucket rain gauges. Measurements between February and November 2010 showed that stemflow amount was highly variable between the different trees. It did not vary much between species but instead varied mainly with tree size. Trees smaller than 35 cm in diameter contributed relatively more stemflow than larger trees; they represented 24% of the total basal area but contributed ~72% of total stemflow at this site. Funneling ratios were larger than one for the trees smaller than 35 cm in diameter and increased with event size up to 50 mm. Funneling ratios for larger trees were less than one and did not vary much with event size. Stemflow started on average after 3 mm of precipitation. Peak stemflow intensities were much larger than peak precipitation intensity for some events and did not always occur at the same time as peak precipitation intensity; peak stemflow intensities tended to increase for consecutive precipitation bursts and occurred approximately 15 minutes after the corresponding peak precipitation intensity. Peak stemflow intensities were not related to tree species or tree size. Even though stemflow accounted for only ~1% of precipitation, high peak stemflow intensities could contribute to fast groundwater recharge and influence soil moisture dynamics around the trees. Dye tracer experiments showed that stemflow infiltrated primarily along roots and was more frequently found at depth than at the soil surface.

  18. Environmental history and tephrostratigraphy at Carp Lake, southwestern Columbia Basin, Washington, USA

    USGS Publications Warehouse

    Whitlock, C.; Sarna-Wojcicki, A. M.; Bartlein, P.J.; Nickmann, R.J.

    2000-01-01

    Sediment cores from Carp Lake provide a pollen record of the last ca. 125,000 years that helps disclose vegetational and climatic conditions from the present day to the previous interglaciation (120-133 ka). The core also contained 15 tephra layers, which were characterised by electron-microprobe analysis of volcanic glass shards. Identified tephra include Mount St. Helens Ye, 3.69 ka; Mazama ash bed, 7.54 ka; Mount St. Helens layer C, 35-50 ka; an unnamed Mount St. Helens tephra, 75-150 ka; the tephra equivalent of layer E at Pringle Falls, Oregon, <218 ka; and an andesitic tephra layer similar to that at Tulelake, California, 174 ka. Ten calibrated radiocarbon ages and the ages of Mount St. Helens Ye, Mazama ash, and the unnamed Mount St. Helens tephra were used to develop an age-depth model. This model was refined by also incorporating the age of marine oxygen isotope stage (IS) boundary 4/5 (73.9 ka) and the age of IS-5e (125 ka). The justification for this age-model is based on an analysis of the pollen record and lithologic data. The pollen record is divided into 11 assemblage zones that describe alternations between periods of montane conifer forest, pine forest, and steppe. The previous interglacial period (IS-5e) supported temperate xerothermic forests of pine and oak and a northward and westward expansion of steppe and juniper woodland, compared to their present occurrence. The period from 83 to 117 ka contains intervals of pine forest and parkland alternating with pine-spruce forest, suggesting shifts from cold humid to cool temperate conditions. Between 73 and 83 ka, a forest of oak, hemlock, Douglas-fir, and fir was present that has no modem analogue. It suggests warm wet summers and cool wet winters. Cool humid conditions during the mid-Wisconsin interval supported mixed conifer forest with Douglas-fir and spruce. The glacial interval featured cold dry steppe, with an expansion of spruce in the late-glacial. Xerothermic communities prevailed in the early Holocene, when temperate steppe was widespread and the lake dried intermittently. The middle Holocene was characterised by ponderosa pine forest, and the modem vegetation was established in the last 3900 yr, when ponderosa pine, Douglas-fir, fir, and oak were part of the local vegetation.

  19. Legacies of historical land use on regional forest composition and structure in Wisconsin, USA (mid-1800s-1930s-2000s).

    PubMed

    Rhemtulla, Jeanine M; Mladenoff, David J; Clayton, Murray K

    2009-06-01

    Historical land use can influence forest species composition and structure for centuries after direct use has ceased. In Wisconsin, USA, Euro-American settlement in the mid- to late 1800s was accompanied by widespread logging, agricultural conversion, and fire suppression. To determine the maximum magnitude of change in forest ecosystems at the height of the agricultural period and the degree of recovery since that time, we assessed changes in forest species composition and structure among the (1) mid-1800s, at the onset of Euro-American settlement; (2) 1930s, at the height of the agricultural period; and (3) 2000s, following forest regrowth. Data sources included the original U.S. Public Land Survey records (mid-1800s), the Wisconsin Land Economic Inventory (1930s), and U.S. Forest Service Forest Inventory and Analysis data (2000s). We derived maps of relative species dominance and tree diameters for the three dates and assessed change using spatial error models, nonmetric multidimensional scaling ordination, and Sørenson distance measures. Our results suggest that since the mid-1800s, hemlock and white pine have declined in absolute area from 22% to 1%, and the proportion of medium (25-<50 cm) and large-diameter (> or = 50 cm) trees of all species has decreased from 71% to 27% across the entire state. Early-successional aspen-birch is three times more common than in the mid-1800s (9% vs. 3%), and maple and other shade-tolerant species are increasing in southern areas formerly dominated by oak forests and savannas. Since the peak agricultural extent in the 1930s, species composition and tree size in northern forests have shown some recovery, while southern forests appear to be on a novel trajectory of change. There is evidence of regional homogenization, but the broad north-south environmental gradient in Wisconsin constrains overall species composition. Although the nature of the future forests will be determined in part by climate change and other exogenous variables, land use is likely to remain the driving factor. PMID:19544743

  20. Late Pliocene and early Pleistocene environments of the north-eastern Russian Arctic inferred from the Lake El'gygytgyn pollen record

    NASA Astrophysics Data System (ADS)

    Andreev, A. A.; Tarasov, P. E.; Wennrich, V.; Raschke, E.; Herzschuh, U.; Nowaczyk, N. R.; Brigham-Grette, J.; Melles, M.

    2013-08-01

    The 318 m thick lacustrine sediment record in Lake El'gygytgyn, northeastern Russian Arctic cored by the international El'gygytgyn Drilling Project provides unique opportunities allowing the time-continuous reconstruction of the regional paleoenvironmental history for the past 3.6 Myr. Pollen studies of the lower 216 m of the lacustrine sediments show their value as an excellent archive of vegetation and climate changes during the Late Pliocene and Early Pleistocene. About 3.50-3.35 Myr BP the vegetation at Lake El'gygytgyn, in nowadays tundra area, was dominated by spruce-larch-fir-hemlock forests. After ca. 3.4 Myr BP dark coniferous taxa gradually disappeared. A very pronounced environmental changes took place at ca. 3.305-3.275 Myr BP, corresponding with the Marine Isotope Stage (MIS) M2, when treeless tundra- and steppe-like habitats became dominant in the regional vegetation. Climate conditions were similar to those of Late Pleistocene cold intervals. Numerous coprophilous fungi spores identified in the pollen samples suggest the presence of grazing animals around the lake. Following the MIS M2 event, larch-pine forests with some spruce mostly dominated in the area until ca. 2.6 Myr BP, interrupted by colder and drier intervals ca. 3.04-3.02, 2.93-2.91, and 2.725-2.695 Myr BP. At the beginning of the Pleistocene, ca. 2.6 Myr BP, noticeable climatic deterioration occurred. Forested habitats changed to predominantly treeless and shrubby environments, which reflect a relatively cold and dry climate. Revealed peaks in green algae colonies (Botryococcus) around 2.53, 2.45, 2.320-2.305 and 2.175-2.150 Myr BP suggest a spread of shallow water environments. Few intervals (i.e. 2.55-2.53, ca. 2.37, and 2.35-2.32 Myr BP) with a higher presence of coniferous taxa (mostly pine and larch) document some relatively short-term climate ameliorations.

  1. Late Pliocene and Early Pleistocene vegetation history of northeastern Russian Arctic inferred from the Lake El'gygytgyn pollen record

    NASA Astrophysics Data System (ADS)

    Andreev, A. A.; Tarasov, P. E.; Wennrich, V.; Raschke, E.; Herzschuh, U.; Nowaczyk, N. R.; Brigham-Grette, J.; Melles, M.

    2014-05-01

    The 318 m thick lacustrine sediment record from Lake El'gygytgyn, northeastern Russian Arctic cored by the international El'gygytgyn Drilling Project provides unique opportunities for the time-continuous reconstruction of the regional paleoenvironmental history for the past 3.6 Myr. Pollen studies of the lower 216 m of the lacustrine sediments demonstrate their value as an excellent archive of vegetation and climate changes during the Late Pliocene and Early Pleistocene. About 3.5-3.35 Myr BP, the vegetation at Lake El'gygytgyn, now an area of tundra was dominated by spruce-larch-fir-hemlock forests. After ca. 3.35 Myr BP dark coniferous taxa gradually disappeared. A very pronounced environmental change took place ca. 3.31-3.28 Myr BP, corresponding to the Marine Isotope Stage (MIS) M2, when treeless tundra- and steppe-like habitats became domi