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1

Within-crown Foliar Plasticity of Western Hemlock, Tsuga heterophylla, in Relation to Stand Age  

E-print Network

Within-crown Foliar Plasticity of Western Hemlock, Tsuga heterophylla, in Relation to Stand Age A from six dierent positions within the crowns of western hemlock, Tsuga heterophylla (Raf.) Sarg., were studied to investigate the plastic response of leaf structure to crown position, in relation to stand age

Richardson, Andrew D.

2

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

NASA Astrophysics Data System (ADS)

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.

Grenon, Frank; Bradley, Robert; Titus, Brian

2014-05-01

3

Effects of fertilization of four hemlock species on Adelges tsugae (Hemiptera: Adelgidae) growth and feeding preference of predators.  

PubMed

Understanding how fertilization affects host resistance to hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is important because fertilizers are often used to grow resistant selections to a suitable size for testing. We evaluated four hemlock species (Tsuga) under three different fertilizer regimes to assess whether fertility affected resistance to the adelgid and to determine whether it affected feeding preferences of the adelgid predators Laricobius nigrinus Fender and Sasajiscymnus tsugae (Sasaji & McClure). Treatments were long-term fertilization (from June 2008 to June 2009), short-term fertilization (from March to June 2009), and no fertilizer. Fertilizer was applied biweekly with 240 ppm N by using water-soluble fertilizer (N-P-K, 20:20:20). Plants (>1 yr old) were artificially infested with adelgids on 31 March 2009. Among unfertilized hemlocks (n=10 per species), foliar N was highest in Tsuga mertensiana (Bong.) CarriBre and lowest in T. chinensis (Franch.) E. Pritz. Significantly more progredien ovisacs or sisten eggs were present on T. mertensiana than on the other hemlock species with none on unfertilized T. chinensis. A. tsugae adults on T. heterophylla (Raf.) Sarg. were unaffected by fertility, but densities of developing A. tsugae nymphs were higher on unfertilized T. heterophylla plants than on fertilized T. heterophylla plants regardless of fertilizer treatment. Both L. nigrinus and S. tsugae consumed more adelgid eggs that developed on fertilized T. canadensis than from unfertilized plants. The predators did not exhibit this preference for adelgid eggs from females that developed on T. heterophylla or T. mertensiana. PMID:21404870

Joseph, S V; Braman, S K; Hanula, J L

2011-02-01

4

Spatial models of competition and gap dynamics in old-growth Tsuga heterophylla\\/Thuja plicata forests  

Microsoft Academic Search

Stem-mapped plots in old-growth forests of western hemlock (Tsuga heterophylla) and western redcedar (Thuja plicata) in northern Idaho, USA were analyzed using Ripley's K(d) function, nearest-neighbor function, and influence zone analyses. A conceptual model of old-growth forest development was formulated from the spatial pattern analyses, to guide the development of a mathematical model. In the conceptual model, cohorts of seedlings

Melinda Moeur

1997-01-01

5

Potential feeding deterrents found in hemlock woolly adelgid, Adelges tsugae  

NASA Astrophysics Data System (ADS)

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.

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

2012-07-01

6

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...

7

Growth and Infestation by Hemlock Woolly Adelgid of Two Exotic Hemlock Species in a New England Forest  

Microsoft Academic Search

The hemlock woolly adelgid (HWA, Adelges tsugae Annand) an invasive exotic insect, may extirpate eastern hemlock (Tsuga canadensis (L.) Carrière) trees from native forests, but other hemlock species could be planted to occupy their ecological niche. This study tests two of the most likely replacement species candidates: western hemlock (T. heterophylla (Raf.) Sargent) and Chinese hemlock (T. chinensis (Franchet) Pritzel).

Alexander M. Evans

2008-01-01

8

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 ...

9

Characterization of terpenoid volatiles from cultivars of eastern hemlock (Tsuga canadensis).  

PubMed

The volatile terpenoid fraction from needles in 13 cultivars of Tsuga canadensis L. (Carriere) was analyzed by gas chromatography with mass spectrometry (GC-MS). The results of this study are considered along with previously reported results for foliar terpenoid levels of the Asian (T. sieboldii, T. chinensis, T. diversifolia), western North American (T. mertensiana, T. heterophylla), and eastern North American species (T. canadensis, T. caroliniana) of hemlock to draw conclusions about the potential of cultivar host resistance to the hemlock woolly adelgid (Adelges tsugae Annand). It is suggested that hemlocks in eastern North America have adapted their terpenoid chemistry for protection against endemic defoliators and that this has made them vulnerable to non-native, sucking pests such as adelgids and scales. Some cultivars of T. canadensis have a terpenoid profile that resembles that of the resistant noneastern North American species and are candidates for biological screening for resistance. Among the cultivars, the variation in terpenoid chemistry did not absolutely correspond with the considerable differences in morphological characters observed, indicating that the terpenoid chemistry is not definitively coupled with hemlock morphology. PMID:18052093

Lagalante, Anthony F; Montgomery, Michael E; Calvosa, Frank C; Mirzabeigi, Michael N

2007-12-26

10

Hemlock woolly adelgid (Adelges tsugae) infestation affects water and carbon relations of eastern hemlock (Tsuga canadensis) and Carolina hemlock (Tsuga caroliniana).  

PubMed

Hemlock woolly adelgid (HWA) is an exotic insect pest causing severe decimation of native hemlock trees. Extensive research has been conducted on the ecological impacts of HWA, but the exact physiological mechanisms that cause mortality are not known. Water relations, anatomy and gas exchange measurements were assessed on healthy and infested eastern (Tsuga canadensis) and Carolina (Tsuga caroliniana) hemlock trees. These data were then used in a mechanistic model to test whether the physiological responses to HWA infestation were sufficiently significant to induce changes in whole-plant water use and carbon uptake. The results indicated coordinated responses of functional traits governing water relations in infested relative to healthy trees. In response to HWA, leaf water potential, carbon isotope ratios, plant hydraulic properties and stomatal conductance were affected, inducing a reduction in tree water use by > 40% and gross primary productivity by 25%. Anatomical changes also appeared, including the activation of traumatic cells. HWA infestation had a direct effect on plant water relations. Despite some leaf compensatory mechanisms, such as an increase in leaf hydraulic conductance and nitrogen content, tree water use and carbon assimilation were diminished significantly in infested trees, which could contribute to tree mortality. PMID:23560452

Domec, Jean-Christophe; Rivera, Laura N; King, John S; Peszlen, Ilona; Hain, Fred; Smith, Benjamin; Frampton, John

2013-07-01

11

Germination ecology in mountain hemlock ( Tsuga mertensiana (Bong.) Carr.)  

Microsoft Academic Search

The effect of variable heat sums (440, 400, 320 and 280°h days), expressed as alternating temperatures (25\\/15, 20\\/15, 20\\/10 and 15\\/10°C over 8\\/16h (day\\/night) regimes), and various stratification treatments (0, 4, 8 and 12 weeks) and their interactions on germination, were investigated using eight natural-stand seedlots of mountain hemlock (Tsuga mertensiana [Bong.] Carr.). The alternating temperature regimes were obtained using

Y. A. El-Kassaby; D. G. W. Edwards

2001-01-01

12

Response of macroarthropod assemblages to the loss of hemlock (Tsuga canadensis), a foundation species  

E-print Network

Response of macroarthropod assemblages to the loss of hemlock (Tsuga canadensis), a foundation species TARA E. SACKETT,1,4, SYDNE RECORD,2 SHARON BEWICK,3 BENJAMIN BAISER,2 NATHAN J. SANDERS,1, Tennessee 37996 USA Abstract. In eastern North American forests, eastern hemlock (Tsuga canadensis

Sanders, Nathan J.

13

Dendroclimatic response of mountain hemlock (Tsuga mertensiana) in Pacific North America  

E-print Network

Dendroclimatic response of mountain hemlock (Tsuga mertensiana) in Pacific North America Ze (Tsuga mertensiana (Bong.) Carrière) in the context of a dendroclimatological analysis. To better'écologie et la physiologie de la pruche subalpine (Tsuga merten- siana (Bong.) Carrière) dans le cadre d

Gedalof, Ze'ev

14

Allozyme variation and recent evolutionary history of eastern hemlock ( Tsuga canadensis ) in the southeastern United States  

Microsoft Academic Search

Eastern hemlock (Tsuga canadensis [L.] Carr.) is a widespread and ecologically important conifer species of eastern North America that is threatened by the\\u000a hemlock woolly adelgid (Adelges tsugae Annand), a pest introduced into the United States from Asia in the 1920s. Information about the genetic composition of eastern\\u000a hemlock is necessary to guide ex situ conservation efforts in the southeastern

K. M. Potter; W. S. Dvorak; B. S. Crane; V. D. Hipkins; R. M. Jetton; W. A. Whittier; R. Rhea

2008-01-01

15

Nitrogen fixation in coarse woody debris of Thuja plicata and Tsuga heterophylla forests on northern Vancouver Island  

Microsoft Academic Search

Asymbiotic nitrogenase activity in coarse woody debris was measured using the acetylene reduction assay un- der ambient conditions in three different stand ages (5, 53, and 88 years old) of an unmanaged second-growth Tsuga heterophylla (Raf.) Sarg. - Abies amabilis (Dougl. ex Loud.) Dougl. ex J. Forbes forest type and a Thuja plicata Donn. ex D. Don - Tsuga heterophylla

Andreas Brunner; J. P. Kimmins

2003-01-01

16

Electrophoretic evidence for genetic differentiation in two host races of hemlock dwarf mistletoe (Arceuthobium tsugense)  

Microsoft Academic Search

Key Word Index--Arceuthobium tsugense; Viscaceae; dwarf mistletoe; electrophoresis; allozymes; host race. Abstract--Three host races of hemlock dwarf mistletoe have been described: the western hemlock race (mainly parasitic on Tsuga heterophylla), the shore pine race (mainly on Pinus contorta ssp. contorta) and the mountain hemlock race (mainly on Tsuga mertensiana and R monticola). Mistletoe shoots from 21 populations representing the three

Daniel L. Nickrent; Adam L. Stell

1990-01-01

17

Dendroclimatic response of mountain hemlock ( Tsuga mertensiana ) in Pacific North America  

Microsoft Academic Search

Abstract: In this paper we review the ecology and physiology of mountain hemlock (Tsuga mertensiana (Bong. ) Carrière) in the context of a dendroclimatological analysis. To better understand the relationship between mountain hemlock growth and climate variability throughout its range we have analyzed chronologies from 10 coastal sites, lo-cated along a transect extending from northern California to southern Alaska. The

Ze'ev Gedalof; Dan J. Smith

2001-01-01

18

Reshaping the Ecology of Invading Populations of Hemlock Woolly Adelgid, Adelges tsugae (Homoptera: Adelgidae), in Eastern North America  

Microsoft Academic Search

Hemlock woolly adelgid, Adelges tsugae Annand (Homoptera: Adelgidae), is native to Japan where it is an innocuous inhabitant of Tsuga diversifolia Masters and T. sieboldii Carriere throughout their natural growing areas. Native adelgid populations are regulated by host resistance and natural enemies, in particular the oribatid mite, Diapterobates humeralis (Hermann) and the coccinellid beetle, Pseudoscymnus tsugae Sasaji and McClure. Invading

Mark S. McClure; Carole A. S.-J. Cheah

1999-01-01

19

Genetic variation in mountain hemlock ( Tsuga mertensiana Bong.): quantitative and adaptive attributes  

Microsoft Academic Search

Patterns of genetic variation for adaptive and quantitative attributes in mountain hemlock (Tsuga mertensiana (Bong.)) seedlings from British Columbia were examined at the population (provenance) and family levels. The population and family levels were represented by 12 provenances and 10 families from a single location, respectively. The adaptive attributes were related to gas exchange (net photosynthesis, transpiration rate, intercellular-to-ambient CO2

Andy Benowicz; Yousry A. El-Kassaby

1999-01-01

20

SHORT-TERM EFFECTS OF PRESCRIBED FIRE IN GRAND FIR-WHITE PINE-WESTERN HEMLOCK  

E-print Network

. Habitat type is western hemlock/ Queencup beadlily (Tsuga heterophylla/Clintonia uniflora-Clin- tonia uniflora phase) (Cooper et al. 1987). Forty-four experimental units were established in a series of small

Fried, Jeremy S.

21

Role of winter temperature and climate change on the survival and future range expansion of the hemlock woolly adelgid ( Adelges tsugae ) in eastern North America  

Microsoft Academic Search

Global climate change has already affected the abundances, range limits, and interactions of many species. The hemlock woolly\\u000a adelgid (Adelges tsugae), an invasive insect introduced to eastern North America from Japan, has decimated stands of eastern hemlock (Tsuga canadensis) and Carolina hemlock (T. caroliniana) from Georgia to Connecticut. However, its spread across central and northern New England has been slowed

Annie Paradis; Joe Elkinton; Katharine Hayhoe; John Buonaccorsi

2008-01-01

22

Efficacy and Duration of Trunk-Injected Imidacloprid in the Management of Hemlock Woolly Adelgid (Adelges tsugae)  

Microsoft Academic Search

Hemlock woolly adelgid (Adelges tsugae) (HWA) is an introduced piercing, sucking insect that affects hemlocks (Tsuga spp.) by extracting carbohydrates from the xylem ray parenchyma cells. Left untreated, HWA will result in reduced shoot growth, branch dieback, and ultimately tree death. In this study, the insecticide IMA-jet (5% imidacloprid w\\/w) was applied by trunk microinjection with the Arborjet Tree I.V.

Joseph J. Doccola; Eric J. Bristol; Samantha D. Sifleet; Joseph Lojko; Peter M. Wild

2007-01-01

23

Variation in Plant Defense against Invasive Herbivores: Evidence for a Hypersensitive Response in Eastern Hemlocks ( Tsuga canadensis )  

Microsoft Academic Search

Herbivores can trigger a wide array of morphological and chemical changes in their host plants. Feeding by some insects induces\\u000a a defensive hypersensitive response, a defense mechanism consisting of elevated H2O2 levels and tissue death at the site of herbivore feeding. The invasive hemlock woolly adelgid Adelges tsugae (‘HWA’) and elongate hemlock scale Fiorinia externa (‘EHS’) feed on eastern hemlocks;

Laura Radville; Arielle Chaves; Evan L. Preisser

2011-01-01

24

The competitive role of Gaultheria shallon on planted western hemlock and western red cedar saplings on northern Vancouver Island  

Microsoft Academic Search

The presence of competing vegetation, particularly salal (Gaultheria shallon Pursh), was studied in relation to growth (measured as height and root collar diameter) of western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western red cedar (Thuja plicata Donn) saplings planted in cedar-hemlock (CH) and hemlock-amabilis fir (HA) phases of an ecosystem type on northern Vancouver Island in British Columbia, Canada. The

L. H. Fraser; C. P. Chanway; Roy Turkington

1995-01-01

25

Ecosystem Response to Hemlock Woolly Adelgid (Adelges tsugae) Induced Tsuga canadensis Mortality  

E-print Network

Shades streams and stabilizes temperatures #12;11/6/2008 8 Justification Terrestrial vegetative changes vireo Blue-throated green warbler (Tingley et al. 2002) Eastern hemlock Aquatic Insects Fish Stream could lead to devastating effects on streams Impacts of Rhododendron on replacement species composition

Gray, Matthew

26

Effects of N addition rates on the productivity of Picea Sitchensis , Thuja plicata , and Tsuga heterophylla seedlings  

Microsoft Academic Search

The effects of differing, exponentially increasing rates of N addition (0.025, 0.05, 0.07 and 0.09 gN gN-1day-1) on photosynthesis, discrimination against13C and partitioning of foliar N to chlorophyll and major photosynthetic proteins were compared in seedlings of the evergreen\\u000a conifersPicea sitchensis, Thuja plicata andTsuga heterophylla. T. heterophylla had the lowest range of foliar N concentrations (Nlm). Across species, photosynthetic rates

K. R. Brown; W. A. Thompson; E. L. Camm; R. D. Guy; B. J. Hawkins

1996-01-01

27

Analysis of terpenoids from hemlock (Tsuga) species by solid-phase microextraction/gas chromatography/ion-trap mass spectrometry.  

PubMed

A sampling method for determining the volatile terpenoid composition from single needles of seven Tsuga species was developed using headspace solid-phase microextraction (SPME). A reproducible sampling method for the volatile components was generated by examination of sample storage, method of needle cutting, and headspace sampling duration. Following SPME collection of the volatile compounds from the seven Tsuga species, gas chromatography/ion-trap mass spectrometry was used to identify 51 terpenoids present in the needle headspace. A semiquantitative method was devised to express individual terpenoid amounts as a percentage of all of the identified peaks in the chromatogram. The semiquantitative results permitted facile interspecies comparison using principal component analysis. Two components were able to account for 90% of the variance and were interpreted as a "species" component and a "resistance/susceptibility" component. Three interspecies groupings were evident from the principal component analysis: (1) Tsuga canadensis and Tsuga caroliniana; (2) Tsuga chinesnsis, Tsuga diversifolia, Tsuga heterophylla, and Tsuga sieboldii; and (3) Tsuga mertensiana. The finding that T. mertensiana was grouped alone and far removed from the other species adds to the morphological evidence that this species should be segregated from other Tsuga. PMID:12670144

Lagalante, Anthony F; Montgomery, Michael E

2003-04-01

28

Effects of N addition rates on the productivity of Picea sitchensis , Thuja plicata , and Tsuga heterophylla seedlings  

Microsoft Academic Search

Seedlings ofPicea sitchensis, Thuja plicata andTsuga heterophylla were supplied N hydroponically at one of four exponentially increasing rates of addition (0.09, 0.07, 0.05, or 0.025 gN-1 day-1) for up to 3 months in a naturally illuminated glasshouse. Relative growth rates (RGR) were analyzed as a function of N uptake,\\u000a the allocation of assimilated N to foliage (LNFR), foliar N concentrations

K. R. Brown; W. A. Thompson; G. F. Weetman

1996-01-01

29

Organic and inorganic nitrogen nutrition of western red cedar, western hemlock and salal in mineral N-limited cedar–hemlock forests  

Microsoft Academic Search

Western red cedar ( Thuja plicata Donn.), western hemlock ( Tsuga heterophylla Raf. Sarge) and salal ( Gaultheria shallon Pursh) are the main species growing in cedar–hemlock forests on Vancouver Island, Canada. Based on the dominance of organic N in these systems, we tested the hypotheses that: (1) organic N can be utilized by the three plant species; and (2)

Jennifer N. Bennett; Cindy E. Prescott

2004-01-01

30

Patterns of genetic variation in mountain hemlock ( Tsuga mertensiana (Bong.) Carr.) with respect to height growth and frost hardiness  

Microsoft Academic Search

Genetic structure (variance among and within populations) and geographic pattern of variations in growth and frost hardiness of mountain hemlock (Tsuga mertensiana (Bong.) Carr.) populations from coastal British Columbia (BC) were examined. Populations fell into two main groups — south coast (16 sources) and north coast (two sources). Height growth of greenhouse grown seedlings was measured during the first growing

Andy Benowicz; Sylvia L’Hirondelle; Yousry A El-Kassaby

2001-01-01

31

Tree mortality caused by the western hemlock looper in landscapes of central British Columbia  

Microsoft Academic Search

An outbreak of the western hemlock looper, Lambdina fiscellaria lugubrosa (Hulst) (Coleoptera: Geometridae), caused tree mortality in central British Columbia, Canada, to stands composed of alpine fir, Abies lasiocarpa (Hook.) Nutt., western hemlock, Tsuga heterophylla (Raf.) Sarg., white spruce, Picea glauca (Moench) Voss, and western red cedar, Thuja plicata Donn. After 4 years, high levels of tree mortality (51–96% of

Rene I Alfaro; S Taylor; G Brown; E Wegwitz

1999-01-01

32

Influence of eastern hemlock (Tsuga canadensis L.) on fish community structure and function in headwater streams of the Delaware River basin  

USGS Publications Warehouse

Hemlock (Tsuga canadensis) forest of the eastern U.S. are in decline due to invasion by the exotic insect hemlock woolly adelgid (Adelges tsugae). Aquatic biodiversity in hemlock ecosystems has not been documented; thus the true impact of the infestation cannot be assessed. We compared ichthyofaunal assemblages and trophic structure of streams draining hemlock and hardwood forests by sampling first- and second-order streams draining 14 paired hemlock and hardwood stands during base flows in July 1997 at the Delaware Water Gap National Recreation Area of Pennsylvania and New Jersey. Over 1400 fish of 15 species and 7 families were collected, but hemlock and hardwood streams individually harbored only one to four species. Brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta) were two to three times as prevalent in hemlock than hardwood streams. Insectivorous fishes occurred in significantly higher proportion in streams of hardwood (0.90) than hemlock (0.46) stands, while piscivores occurred more often in hemlock (0.85) than hardwood (0.54) stands. Functional (trophic) diversity of fishes in hemlock and second-order streams was numerically greater than that of hardwood and first-order streams. Species composition also differed by stream order and terrain type. Biodiversity is threatened at several levels within hemlock ecosystems at risk to the hemlock woolly adelgid in eastern U.S. forests.

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

2003-01-01

33

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

USGS Publications Warehouse

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.

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

1999-01-01

34

Factors affecting establishment and recovery of Sasajiscymnus tsugae (Coleoptera: Coccinellidae), an introduced predator of hemlock woolly adelgid (Hemiptera: Adelgidae) on eastern hemlock (Pinales: Pinaceae).  

PubMed

To reduce populations of hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), >500,000 Sasajiscymnus tsugae (Sasaji and McClure) (Coleoptera: Coccinellidae) have been released in the Great Smoky Mountains National Park since 2002. To determine factors affecting establishment and recovery of these predatory beetles, 65 single release sites were sampled using beat sheets from 2008 to 2012. Several abiotic and biotic factors were evaluated for their association with establishment and recovery of S. tsugae. Information on predatory beetle releases (location, year of release, number released, and season of release), topographic features (elevation, slope, Beers transformed aspect, and topographic relative moisture index), and temperature data (minimum and maximum temperatures 1 d after release and average minimum and maximum temperatures 7 d after release) were obtained from Great Smoky Mountains National Park personnel. These factors were evaluated using stepwise logistic regression and Pearson correlation. S. tsugae was recovered from 13 sites 2 to 10 yr after release, and the greatest number was recovered from 2002 release sites. Regression indicated establishment and recovery was negatively associated with year of release and positively associated with the average maximum temperature 7 d after release and elevation (generally, recovery increased as temperatures increased). Several significant correlations were found between presence and number of S. tsugae and year of release, season of release, and temperature variables. These results indicate that releases of S. tsugae should be made in warmer (?10-25°C) temperatures and monitored for at least 5 yr after releases to enhance establishment and recovery efforts. PMID:24468557

Hakeem, A; Grant, J F; Wiggins, G J; Lambdin, P L; Hale, F A; Buckley, D S; Rhea, J R; Parkman, J P; Taylor, G

2013-12-01

35

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

PubMed

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

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

2013-07-01

36

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

Microsoft Academic Search

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,

1995-01-01

37

"NH Big Tree of the Month March 2007" Eastern Hemlock Tsuga Canadensis  

E-print Network

of moss and lichens on the bark. Tannin makes hemlock logs and stumps slow to rot. Tom Wessels in his book closely related to aphids. They feed on the tips of young branches, cleverly avoiding the tree tannins

New Hampshire, University of

38

A Case Study: Looking at the Effects of Fragmentation on Genetic Structure in Different Life History Stages of Old-Growth Mountain Hemlock (Tsuga mertensiana)  

Microsoft Academic Search

We examined fine-scale genetic structure of mountain hemlock (Tsuga mertensiana) in an old-growth stand and an adjacent seedling population, with the goal of detecting the effects of fragmentation. Three hundred and six old-growth trees and 195 naturally regenerating seedlings were genotyped at 5 microsatellite loci. Genetic diversity was similar across old-growth life stages and within the clear-cut seedlings. Significant inbreeding

DILARA ALLY; KERMIT RITLAND

2006-01-01

39

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

PubMed

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

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

2011-08-01

40

Resistance of Hemlock species and hybrids to 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 ...

41

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

SciTech Connect

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.

Taylor, A.H. [Pennsylvania State Univ., University Park, PA (United States)

1995-08-01

42

Shoot water relations and gas exchange of western hemlock and western red cedar seedlings during establishment on a reforestation site  

Microsoft Academic Search

Shoot water relations, summer gas exchange response and morphological development of western hemlock [Tsuga heterophylla (Raf.) Sarg.] and western red cedar (Thuja plicata Donn) seedlings were monitored over the first growing season on a coastal reforestation site in British Columbia. In March, osmotic potential (?s) at saturation [?s(sat)] was -1.98 MPa and turgor loss point [?s(tlp)] -2.38 MPa for western

Steven C. Grossnickle

1993-01-01

43

Climatic significance of the stable carbon isotope composition of tree-ring cellulose: Comparison of Chinese hemlock ( Tsuga chinensis Pritz) and alpine pine ( Pinus densata Mast) in a temperate-moist region of China  

Microsoft Academic Search

In the reconstruction of past climate using stable carbon isotope composition (?\\u000a 13C) in tree ring, the responses of the stable carbon composition (?\\u000a 13C) of multiple tree species to environmental factors must be known detailedly. This study presented two ?\\u000a 13C series in annual tree rings for Chinese hemlock (Tsuga chinensis Pritz) and alpine pine (Pinus densata Mast), and

XiaoHong Liu; XueMei Shao; LiLi Wang; LiangJu Zhao; Pu Wu; Tuo Chen; DaHe Qin; JiaWen Ren

2007-01-01

44

A case study: looking at the effects of fragmentation on genetic structure in different life history stages of old-growth mountain hemlock (Tsuga mertensiana).  

PubMed

We examined fine-scale genetic structure of mountain hemlock (Tsuga mertensiana) in an old-growth stand and an adjacent seedling population, with the goal of detecting the effects of fragmentation. Three hundred and six old-growth trees and 195 naturally regenerating seedlings were genotyped at 5 microsatellite loci. Genetic diversity was similar across old-growth life stages and within the clear-cut seedlings. Significant inbreeding was found in the adult class (30+ cm diameter at breast height) of old-growth seedlings and in the adjacent natural regeneration. Relatedness was significantly associated with physical distance for both the oldest age class and for regenerating seedlings in the adjacent clear-cut, whereas intermediate classes showed no such association. As intermediate classes show no isolation by distance, the associations that arise probably occur from single cohort regeneration that clearly has taken place in the clear-cut, and possibly when the oldest old-growth trees were established. Parentage analysis suggested that large-scale fragmentation, such as this clear-cut, allowed for increased long-distance seed dispersal. We conclude that long-lived tree populations can consist of a cohort mosaic, reflecting the effects of fragmentation, and resulting in a complex, age-dependent, local population structure with high levels of genetic diversity. PMID:17150981

Ally, Dilara; Ritland, Kermit

2007-01-01

45

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

Microsoft Academic Search

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\\u000a physical, chemical, and biological alterations to stream environments. To assess the influence of riparian

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

2009-01-01

46

Influences of Eastern Hemlock Mortality on Nutrient Cycling  

Microsoft Academic Search

Mortality of eastern hemlock (Tsuga canadensis (L.) Carriere) may be caused by a variety of agents, but hemlock trees of all sizes over a large geographic area are currently threatened by an outbreak of the hemlock woolly adelgid (HWA: Adelges tsugae Annand) in the eastern United States. In this paper, we review what is currently known about changes in nutrient

Thad E; Jennifer C. Jenkins; Donald J. Leopold; Dudley J. Raynall

47

Breeding Hemlocks for Resistance to Hemlock Woolly Adelgid  

Microsoft Academic Search

The eastern North American native hemlock species, Tsuga canadensis and T. caroliniana, are highly susceptible to injury from the hemlock woolly adelgid (HWA); while the Asian species, T. chinensis (Franch.) E. Pritz; T. diversifolia (Maxim.) Mast.; and T. sieboldii Carriere are reported to show more tolerance (McClure 1992, 1995). In western North America, the adelgid is not considered a pest

S. E. Bentz; Louise G. H. Riedel; Margaret R. Pooler; A. M. Townsend

48

A geographically variable model of hemlock woolly adelgid spread  

Microsoft Academic Search

The hemlock woolly adelgid (HWA) (Adelges tsugae) has spread through the range of eastern hemlock (Tsuga canadensis) leaving dead hemlock trees in its wake. We combined county and previously unavailable township level infestation records\\u000a with geographic variables including plant hardiness zone, elevation, forest cover type, urbanization, precipitation, temperature,\\u000a and hemlock range in a geographic information system to build models linking

Alexander M. Evans; Timothy G. Gregoire

2007-01-01

49

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

PubMed

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 (?(13)Ccell, ?(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 ?(13)Ccell and ?(18)Ocell than uninfected trees. Differences in ?(18)Ocell between infected and uninfected trees were unexpected given that stomatal conductance and environmental variables that were expected to influence the ?(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 ?(18)Ocell. This study reconstructs the long-term physiological responses of western hemlock to dwarf mistletoe infection. The long-term diameter growth and ?(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 ?(13)Ccell and indicates that changes in leaf internal properties such as gm and L that affect ?(18)Ocell must be considered. PMID:24973917

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

50

Arboreal spiders in eastern hemlock.  

PubMed

Eastern hemlock [Tsuga canadensis (L.) Carrière] is a foundation species in forests of eastern North America that plays a key role in ecosystem function. It is highly susceptible to the exotic invasive hemlock woolly adelgid (Adelges tsugae Annand), which is causing widespread hemlock mortality. We surveyed the spider communities of eastern hemlock and deciduous canopies over 2 yr, collecting over 4,000 spiders from 21 families. We found that eastern hemlock canopies harbored a more abundant, rich, and diverse spider community than did deciduous canopies. Five spider families were present in our hemlock collections that were absent from the deciduous collections, including Mysmenidae, Theridiosomatidae, Mimetidae, Lycosidae, and Agelenidae. In hemlock canopies there were 4× the number of web builders, consisting primarily of the Tetragnathidae and Araneidae, than active hunters, consisting primarily of the Anyphaenidae and the Salticidae. Ours is the first in depth study of the spider community in eastern hemlock. Spider abundance in hemlock canopies suggest that they may play a role regulating herbivore populations, and could possibly affect the invasive hemlock woolly adelgid, either through direct consumption of the adelgids themselves or through interactions with classical biological control agents. PMID:22217752

Mallis, Rachael E; Rieske, Lynne K

2011-12-01

51

Organic and inorganic nitrogen nutrition of western red cedar, western hemlock and salal in mineral N-limited cedar-hemlock forests.  

PubMed

Western red cedar (Thuja plicata Donn.), western hemlock (Tsuga heterophylla Raf. Sarge) and salal (Gaultheria shallon Pursh) are the main species growing in cedar-hemlock forests on Vancouver Island, Canada. Based on the dominance of organic N in these systems, we tested the hypotheses that: (1) organic N can be utilized by the three plant species; and (2) salal, which is ericoid mycorrhizal and has high tannin concentration in its tissues, would absorb more N from the complex organic N compounds than the other two species. The abilities of cedar, hemlock and salal to take up 15N,13C-labelled glutamic acid were measured and the capacities of the three species to use nitrate (NO3-), ammonium (NH4+), glutamic acid, protein and protein-tannin N were compared over a 20-day period. Based on 13C enrichment, all three species absorbed at least a portion of glutamic acid intact. Cedar, hemlock and salal also showed similar patterns of N uptake from the NO3-, NH4+, glutamic acid, protein and protein-tannin treatments. The largest proportions of applied N were taken up from the NO3- and NH4+ treatments while smaller amounts of N were absorbed from the organic N compounds. Thus organic N was accessed to a modest degree by all three species, and salal did not have a greater capacity to utilize protein and protein-tannin-N. PMID:15322895

Bennett, Jennifer N; Prescott, Cindy E

2004-11-01

52

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

Federal Register 2010, 2011, 2012, 2013, 2014

...hemlock woolly adelgid is a destructive pest of the eastern hemlock (Tsuga canadensis), where it causes needle loss, abortion of buds, and the eventual death of infested trees. Four predatory beetles have been introduced to the eastern United...

2012-08-03

53

Landscape patterns of hemlock decline in New England due to the introduced hemlock woolly adelgid  

Microsoft Academic Search

Aim The hemlock woolly adelgid (HWA; Adelges tsugae Annand), a small, aphid-like insect native to Japan, is currently migrating northward through eastern North America and threatens to eliminate eastern hemlock (Tsuga canadensis (L.) Carriere), one of the most abundant, long-lived shade tolerant species, across its range. The major objectives of this study were: (1) to characterize the pre-HWA distribution, composition,

David A. Orwig; David R. Foster; David L. Mausel

2002-01-01

54

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

PubMed Central

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

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

2014-01-01

55

Avian response to removal of a forest dominant: consequences of hemlock woolly adelgid infestations  

Microsoft Academic Search

Aim This study examines changes in avian community composition associated with the decline and loss of eastern hemlock (Tsuga canadensis (L.) Carr.) resulting from chronic hemlock woolly adelgid (HWA; Adelges tsugae Annand) infestations. Location The study was conducted in a 4900-km2 study region extending from Long Island Sound northward to the southern border of Massachusetts and including the Connecticut River

Morgan W. Tingley; David A. Orwig; Rebecca Field; Glenn Motzkin

2002-01-01

56

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

SciTech Connect

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.

Pong, W.Y.; Waddell, Dale R.; Biomass and Energy Project (Portland, Or.)

1985-03-15

57

Tsuga canadensis in Ohio: Synecological and phytogeographical relationships  

Microsoft Academic Search

Summary Tsuga canadensis is the dominant in four topo-edaphic associations and one edaphic association in Ohio. WhileTsuga may occur withPinus strobus and a variety of deciduous trees (e.g.,Fagus grandifolia, Acer saccharum) in these communities, only hemlock is persistently reproducing. As compared with the contiguous mesophytic deciduous forest, these associations have a depauperate understory, a possible consequence of the shallow and

R. Alan Black; Richard N. Mack

1976-01-01

58

Hemlock Tsuga canadensis Yellow Birch Betula alleghaniensis  

E-print Network

saccharum Beech Fagus grandifolia Cedar Thuja occidentalis Tamarack Larix laricina Jack Pine Pinus banksiana Red Pine Pinus resinosa White Pine Pinus strobus Red Oak Quercus rubra Black Oak Quercus velutina No Data WISCONSIN'S 1832-1866 PUB-CE-4017 2009 Tree labels below indicate the dominant and most abundant

Mladenoff, David

59

Understory vegetation in old-growth and second-growth Tsuga canadensis forests in western Massachusetts  

Microsoft Academic Search

We compared the understory communities (herbs, shrubs, and tree seedlings and saplings) of old-growth and second-growth eastern hemlock forests (Tsuga canadensis) in western Massachusetts, USA. Second-growth hemlock forests originated following clear-cut logging in the late 1800s and were 108–136 years old at the time of sampling. Old-growth hemlock forests contained total ground cover of herbaceous and shrub species that was

Anthony W. D’Amato; David A. Orwig; David R. Foster

2009-01-01

60

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

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

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

2011-01-01

61

Avian response to removal of a forest dominant: consequences of hemlock woolly  

E-print Network

associated with the decline and loss of eastern hemlock [Tsuga canadensis (L.) Carr.] resulting from chronic (Sitta carolinensis), red-eyed vireo (Vireo olivaceus), hooded warbler (Wilsonia citrina), and several

Tingley, Morgan W.

62

Short Paper Analysis of hemlock pollen size in Holocene lake sediments from New England  

E-print Network

-vegetation calibration studies show background levels of 0­10% Tsuga pollen for sites where the tree is not presentShort Paper Analysis of hemlock pollen size in Holocene lake sediments from New England Lindsay T-Holocene decline of Tsuga canadensis by measuring the diameters of pollen grains in two lake-sediment cores from

Oswald, Wyatt

63

Losses Caused by Annosus Root Disease in Pacific Northwest Forests1 Ellen Michaels Goheen Donald J. Goheen  

E-print Network

, the pines, and the true firs. HEMLOCKS Western hemlock (Tsuga heterophylla (Raf.) Sarg.) in westside stands and mountain hemlock (T. mertensiana (Bong.) Carr.) in the high Cascades are commonly infected

Standiford, Richard B.

64

Mid-Holocene Hemlock Decline in Eastern North America Linked with Phytophagous Insect Activity  

NASA Astrophysics Data System (ADS)

Macrofossil evidence indicates that the mid-Holocene hemlock [ Tsuga canadensisL. (Carr.)] decline that occurred over a wide area in eastern North America was associated with phytophagous insect activity. In situhemlock macrofossils and insect remains found in a paludified dunefield at the northern limit of hemlock testify that two defoliation events occurred at 4910 ± 90 and 4200 ± 100 yr B.P., respectively. The sharp coincidence of remains from hemlock needles with chewing damage typical of hemlock looper feeding, head capsules from the hemlock looper ( Lambdina fiscellaria) and the spruce budworm ( Choristoneura fumiferana), absence of hemlock fruiting remains, and tree-ring anomalies in fossil hemlocks that died prematurely (<165 yr) suggest that defoliation affected hemlock reproductive capacity and pollen productivity, or more likely caused mass mortality. Our findings indicate that defoliation can affect ecosystems for centuries, especially when long-lived tree species are involved.

Bhiry, Najat; Filion, Louise

1996-05-01

65

Biomass Distribution in Western Hemlock, Douglas-Fir and Western Redcedar.  

SciTech Connect

This report presents results from a study characterizing the weight and volume of trees from overstocked (doghair) 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. There are approximately 20,000 acres classed as doghair on the Quilcene District. In order to evaluate their harvesting and utilization potential accurate estimates of volume and weight of entire trees and stands are needed. The objective of this study was to characterize the biomass of the three major tree species located in overstocked stands by providing estimators to predict the green and dry weight of the total tree, as well as separate predictions for the components of stem and crown. Additional objectives included estimates for the weight of the 'standing dead', the weight of the dead material on the forest floor, and estimators to predict the cubic volume of the wood and bark in the stems. 11 refs., 9 figs., 15 tabs.

Pong, W.Y.; Waddell, Dale R.; Biomass and Energy Project (Portland, Or.)

1986-05-30

66

Diagnosis of Annosus Root Disease in Mixed Conifer Forests in the Northwestern United States1  

E-print Network

(Tsuga heterophylla), mountain hemlock (T. mertensiana), grand fir (Abies grandis), white fir (A), subalpine fir (A. lasiocarpa), and California red fir (A. magnifica) (Hadfield and others, 1986). Other

Standiford, Richard B.

67

Effects of the Hemlock Woolly Adelgid on Nitrogen Losses from  

E-print Network

parasitica), Dutch elm disease (Ophiostoma spp.), the emerald ash borer (Agrilus spp.), the gypsy moth Ecosystems Pamela H. Templer* and Tiffany M. McCann Department of Biology, Boston University, Boston- agement regimes used to control the hemlock woolly adelgid (Adelges tsugae), such as salvage cutting, may

Templer, Pamela

68

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

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

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

2008-04-01

69

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

NASA Astrophysics Data System (ADS)

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.

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

2009-08-01

70

The competitive role of Gaultheria shallon on planted western hemlock and western red cedar saplings on northern Vancouver Island  

Microsoft Academic Search

The presence of competing vegetation, particularly salal (Gaultheria shallon F'ursh), was studied in relation to growth (measured as height and root collar diameter) of western hemlock (Tsugu heterophylla (Raf.) Sarg.) and western red cedar (Thuju plicutu Dorm) saplings planted in cedar-hemlock (CH) and hemlock-amabilis fir (HA) phases of an ecosystem type on northern Vancouver Island in British Columbia, Canada. The

L. H. Fraser af; C. P. Chanway; Roy Turkington

1995-01-01

71

Dispersal versus climate: Expansion of Fagus and Tsuga into the Upper Great Lakes region  

Microsoft Academic Search

Pollen records for American beech (Fagus grandifolia) and eastern hemlock (Tsuga canadensis) compiled from 50 sites in Michigan and Wisconsin, USA, show that both species entered the Upper Great Lakes region about 7000 yr B.P., reaching their western and southwestern boundaries between 2000 and 1000 yr B.P. Fagus advanced northward into lower Michigan as a continuous front, except where Lake

M. B. Davis; K. D. Woods; S. L. Webb; R. P. Futyma

1986-01-01

72

Daniel G. Gavin1 , Department of Geography, University of Oregon, Eugene, Oregon 97403-1251  

E-print Network

by the range ofTsuga heterophylla(western hemlock) and Thuja plicata (western redcedar). Especially towards. 2006). Pollen records from the central and southern end of interior Thuja-Tsuga forests show

Gavin, Daniel G.

73

Mid-Holocene Hemlock Decline in Eastern North America Linked with Phytophagous Insect Activity  

Microsoft Academic Search

Macrofossil evidence indicates that the mid-Holocene hemlock [Tsuga canadensisL. (Carr.)] decline that occurred over a wide area in eastern North America was associated with phytophagous insect activity.In situhemlock macrofossils and insect remains found in a paludified dunefield at the northern limit of hemlock testify that two defoliation events occurred at 4910 ± 90 and 4200 ± 100 yr B.P., respectively.

Najat Bhiry; Louise Filion

1996-01-01

74

Web orientation and prey resources for web-building spiders in eastern hemlock.  

PubMed

We examined the arthropod community on eastern hemlock, Tsuga canadensis (L.) Carr, in the context of its role in providing potential prey items for hemlock-associated web-weaving spiders. Using sticky traps simulating spider webs, we evaluated what prey items are available to web-weaving spiders in eastern hemlock based on web orientation (horizontal versus vertical) and cardinal direction. We found that the overwhelming majority (>70%) of prey items available to spiders in hemlock canopies were Diptera. Psocoptera, Hymenoptera, and Hemiptera comprised most of the remaining potential prey. A significant direction × orientation interaction, and greater trap capture in some direction-orientation combinations, suggests that spiders might locate their webs in eastern hemlock canopies for thermoregulatory purposes, ultimately optimizing prey capture. We also evaluated these findings in the context of hemlock infestation by the invasive hemlock woolly adelgid, Adelges tsugae Annand. The adelgid is a sedentary insect with a mobile crawler stage that provides a readily available, easily obtained food source for predators in hemlock canopies. However, an abundance of alternative prey will affect within canopy spider distribution and the potential intensity with which spiders consume these prey. Understanding the response of spiders to potential prey availability is essential to understanding the trophic interactions involving these predators and their potential for influencing herbivore populations. PMID:22546441

Mallis, Rachael E; Rieske, Lynne K

2010-10-01

75

Mountain Hemlock Growth Responds to Climatic Variability at Annual and Decadal Time Scales  

Microsoft Academic Search

Improved understanding of tree growth responses to climate is needed to model and predict forest ecosystem responses to current and future climatic variability. We used dendroecological methods to study the effects of climatic variability on radial growth of a subalpine conifer, mountain hemlock (Tsuga mertensiana). Tree-ring chronologies were developed for 31 sites, spanning the latitudinal and elevational ranges of mountain

David W. Peterson; David L. Peterson

2001-01-01

76

Spatial tools for managing hemlock woolly adelgid in the southern Appalachians  

NASA Astrophysics Data System (ADS)

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.

Koch, Frank Henry, Jr.

77

Mesohabitat use of threatened hemlock forests by breeding birds of the Delaware River basin in northeastern United States  

USGS Publications Warehouse

Avian biodiversity may be at risk in eastern parks and forests due to continued expansion of the hemlock woolly adelgid (Adelges tsugae), an exotic homopteran insect native to East Asia. To assess avian biodiversity, mesohabitat relations, and the risk of species loss with declining hemlock forests in Appalachian park lands, 80 randomly distributed fixed-radius plots were established in which territories of breeding birds were estimated on four forest-terrain types (hemlock and hardwood benches and ravines) in the Delaware Water Gap National Recreation Area. Both species richness and number of territories were higher in hardwood than hemlock forest types and in bench than ravine terrain types. Four insectivorous species, Acadian flycatcher (Empidonax virescens), blue-headed vireo (Vireo solitarius), black-throated green warbler (Dendroica virens), and Blackburnian warbler (Dendroica fusca), showed high affinity for hemlock forest type and exhibited significantly greater numbers of territories in hemlock than hardwood sites. These species are hemlock-associated species at risk from continued hemlock decline in the Delaware River valley and similar forests of the mid-Atlantic east slope. Two of these species, the blue-headed vireo and Blackburnian warbler, appeared to specialize on ravine mesohabitats of hemlock stands, the vireo a low-to-mid canopy species, the warbler a mid-to-upper canopy forager. Unchecked expansion of the exotic adelgid and subsequent hemlock decline could negatively impact 3,600 pairs from the park and several million pairs from northeastern United States hemlock forests due to elimination of preferred habitat.

Ross, R.M.; Redell, L.A.; Bennett, R.M.; Young, J.A.

2004-01-01

78

Composition and Structure of Hemlock-Dominated Riparian Forests of the Northern Allegheny Plateau: A Baseline Assessment  

Microsoft Academic Search

We assessed the species composition and structure of three riparian forest stands of differing ages (old-growth, late- successional, mid-successional), dominated by eastern hemlock (Tsuga canadensis Carr.), in the Allegheny National Forest of northwestern Pennsylvania. Our objectives were to: 1) quantify structural and compositional attributes of hemlock-dominated riparian forests along a successional chronosequence; 2) describe in-stream coarse woody debris (CWD; logs

Charles E. Williams; William J. Moriarity

79

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

PubMed

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

Stadler, Bernhard; Müller, Thomas; Orwig, David

2006-07-01

80

Genetic control of germination and the effects of accelerated aging in mountain hemlock seeds and its relevance to gene conservation  

Microsoft Academic Search

Genetic control of germination parameters and the effects of accelerated aging in mountain hemlock (Tsuga mertensiana [Bong.] Carr.) seeds were investigated using standard germination tests and simulated aging, respectively. Germination parameters were studied on seeds collected from individual trees from two natural populations (Sooke and San Juan) located on southern Vancouver Island, BC. Strong genetic control was confirmed by the

Y. A. El-Kassaby; D. G. W. Edwards

1998-01-01

81

Activity and Residues of Imidacloprid Applied to Soil and Tree Trunks to Control Hemlock Woolly Adelgid (Hemiptera: Adelgidae) in Forests  

Microsoft Academic Search

We studied imidacloprid application methods and timing to control the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), in forests. The methods compared were 1) soil injection near the trunk; 2) soil injection dispersed throughout the area under the canopy; 3) soil drench near the base of the trunk; and trunk injection with the 4) Arborjet, 5) Wedgle, and 6)

R. S. Cowles; M. E. Montgomery; C. A. S.-J. CHEAH

2006-01-01

82

Growth of planted tree seedlings in response to ambient light levels in northwestern interior cedar-hemlock forests of British Columbia  

Microsoft Academic Search

Insights into field-planted conifer seedling growth were gained by fitting height and diameter growth to relative irradiance over the growing season using Michaelis-Menten functions. There was little difference among tree species (Abies lasiocarpa (Hook.) Nutt., Picea glauca (Moench) Voss ? Picea sitchensis (Bong.) Carr., Pinus contorta Dougl. ex Loud., Thuja plicata Donn ex D. Don, Tsuga heterophylla (Raf.) Sarg.) in

K. Dave Coates; Philip J. Burton

1999-01-01

83

The effect of disturbance by Phellinus weirii on decomposition and nutrient mineralization in a Tsuga mertensiana forest  

Microsoft Academic Search

Microbial biomass in the upper 7 cm of soil and needle decomposition on the forest floor were measured seasonally for 10 months in a mountain hemlock (Tsuga mertensiana) old-growth forest and in a regrowth forest after Phellinus weirii, a root-rot pathogen infection, had caused disturbance. The microbial biomass was higher in the old-growth forest soil than in the regrowth forest

K. Cromack; J. A. Entry; T. Savage

1991-01-01

84

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

PubMed

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

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

2013-06-01

85

Silvicultural Tools Applicable in Forests Burned by a Mixed Severity Fire Regime Russell T. Graham  

E-print Network

of the moist, (e.g., western hemlock, Tsuga heterophylla; grand fir, Abies grandis; western redcedar, Thuja plicata ), cold (e.g., subalpine fir, Abies lasiocarpa; Engelmann spruce, Picea engelmannii), a

Fried, Jeremy S.

86

Draft Umatilla/Willow Subbasin Plan May 28, 2004 Appendix D: Focal Habitat Descriptions D-1  

E-print Network

species growing in the undergrowth. On moist sites, grand fir (Abies grandis), western redcedar (Thuja plicata) and/or western hemlock (Tsuga heterophylla) are dominant or co-dominant with Douglas-fir. Other

87

Clearwater Subbasin Assessment 116 November 2003 5 Vegetative Resources  

E-print Network

and parts of the Selway River. Under these unique climatic conditions grand fir gives way to western red cedar and hemlock (Tsuga heterophylla) stands. Cedar forests often contain unique plant species

88

Density-dependent eects on tree survival in an old-growth Douglas r forest  

E-print Network

of the invading late-successional species western hemlock (Tsuga heterophylla) and western red cedar (Thuja mortality tended to be higher in denser patches of western red cedar. 5 Our results emphasize the importance

He, Fangliang

89

Fisher (Martes pennanti) Use of a Managed Forest in Coastal Northwest California1  

E-print Network

. The cavities were in two tanoaks, two Douglas fir snags and one western red cedar (Thuja plicata) snag western hemlock (Tsuga heterophylla), western red cedar and Douglas-fir. The most common structures used

Standiford, Richard B.

90

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

PubMed Central

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

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

2012-01-01

91

Spatial and temporal distribution of residues of imidacloprid and its insecticidal 5-hydroxy and olefin and metabolites in eastern hemlock (Pinales: Pinaceae) in the southern Appalachians.  

PubMed

Widespread mortality of eastern hemlock, Tsuga canadensis (L.) Carrière, resulting from infestation by hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), has occurred throughout the native range of eastern hemlock within the eastern United States. Imidacloprid, a systemic insecticide, is one of the primary chemical compounds used to control hemlock woolly adelgid in both urban and, in a limited manner, in natural forest environments. The metabolism of imidacloprid in eastern hemlock produces 12 metabolites; two of these, imidacloprid 5-hydroxy and imidacloprid olefin, are considered toxicologically important metabolites. However, little is known about the persistence of these metabolites in eastern hemlock in the southern Appalachians. Concentrations ofimidacloprid, olefin, and 5-hydroxy were quantified by using HPLC/MS/MS techniques. Over the 3-yr study, concentrations of imidacloprid and consequent 5-hydroxy and olefin were highest in trees treated with a soil injection in the spring. Imidacloprid and 5-hydroxy concentrations in sap were highest at 12 mo posttreatment and in tissue at 15 mo posttreatment. Imidacloprid was detected through 36 mo posttreatment and 5-hydroxy was detected through 15 mo posttreatment. Olefin concentrations in both sap and tissue were highest at 36 mo posttreatment and were detected in high concentrations through 36 mo posttreatment. Concentrations of imidacloprid were highest in the bottom stratum of the canopy and lowest in the top stratum. Concentrations of olefin and 5-hydroxy were highest in the top stratum and lowest in the bottom stratum. PMID:24498740

Coots, Carla; Lambdin, Paris; Grant, Jerome; Rhea, Rusty

2013-12-01

92

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

PubMed

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-mediatedeffects on seedling dynamics. In hemlock-dominatedstands, 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-occurringbirch 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-nutrientconcentrations 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

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

2015-02-01

93

Variation of the Nuclear, Subnuclear and Chromosomal Flavanol Deposition in Hemlock and Rye  

PubMed Central

Nuclei of hemlock (Tsuga canadensis and Tsuga canadensis var. nana) were investigated for the presence of flavanols. Histochemical staining with p-dimethylaminocinnamaldehyde proved to be a highly valuable method yielding a bright blue flavanol coloration for nuclei. There was a significant variation in flavanol deposition (1) among nuclei, (2) at the subnuclear level and also (3) along the chromosomes during mitosis. The presence of flavanols in nucleoli could not be established probably because they were too small, measuring less than 1 ?m in diameter. In contrast to Tsuga, the cells and nuclei of rootlets from rye (Secale cereale) were totally devoid of natural flavanols. However, externally added flavanols, catechin and epicatechin, were bound to the rye nuclei, while the rather large nucleoli failed to associate with the flavanols. The strong sink activity of nucleoplasm and chromosomes for flavanols in Tsuga and Secale indicates a process which is apparently widespread even in distantly related plant species. Variations in chromatin-associated flavanols could to some extent be induced by acetylation/deacetylation of histones, as confirmed in the present study by means of UVVIS spectroscopic titrations of histone sulphate and chemically acetylated histone sulphate.

Feucht, Walter; Dithmar, Heike; Polster, Jürgen

2007-01-01

94

Hemlock: murder before the Lord.  

PubMed

Two healthy young men were killed by a plume of hemlock (Conium maculatum) emitted when contaminated incense was vaporized during religious rites about the middle of the thirteenth century BC. PMID:7830518

Davies, M L; Davies, T A

1994-10-01

95

Characterization of the Soil Hydromorphic Conditions in a Paludified Dunefield during the Mid-Holocene Hemlock Decline near Québec City, Québec  

Microsoft Academic Search

The mid-Holocene eastern hemlock [Tsuga canadensisL. (Carr.)] decline has been recently attributed to the activity of insect defoliators. N. Bihiry and L. Filion,Quaternary Research45,312–320 (1996). In this study, soil hydromorphic conditions were investigated for the period 6800–3200 yr B.P. using micromorphological data from a peat section from a swale in a paludified dunefield in southern Québec. After a short period

Najat Bhiry; Louise Filion

1996-01-01

96

COMMUNITY ECOLOGY Adrian Weber Justine Karst Benjamin Gilbert  

E-print Network

boundaries between mixed red cedar (Thuja plicata)-hemlock (Tsuga heterophylla) (CH) stands, and stands of hemlock and amabilis fir (Abies amabilis) (HA). We tested differences in AM coloniza- tion of red cedar between ectomycorrhiza-dominated (HA) stands and stands containing red cedar (CH), across a range of light

Gilbert, Benjamin

97

Thuja plicata exclusion in ectomycorrhiza-dominated forests: testing the role of inoculum potential of arbuscular mycorrhizal fungi  

Microsoft Academic Search

The ability of trees dependent on arbuscular mycorrhizal (AM) fungi to establish in ectomycorrhizal forests is unknown. On northern Vancouver Island, Canada, there are sharp boundaries between mixed red cedar ( Thuja plicata)-hemlock ( Tsuga heterophylla) (CH) stands, and stands of hemlock and amabilis fir ( Abies amabilis) (HA). We tested differences in AM colonization of red cedar between ectomycorrhiza-dominated

Adrian Weber; Justine Karst; Benjamin Gilbert; J. P. Kimmins

2005-01-01

98

Influence of sulfometuron methyl on conifer seedling root development  

E-print Network

), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western red-cedar (Thuja plicata Donn ex D. Don growth, western red-cedar seedlings showed the greatest negative impact to site prepara- tion compared Western hemlock Á Western red-cedar O. T. Burney Á D. F. Jacobs (&) Hardwood Tree Improvement

99

Understory competition effect on tree growth and biomass allocation on a coastal old-growth forest cutover site in British Columbia  

Microsoft Academic Search

We studied the effect of salal (Gaultheria shallon Pursh.) competition on height, diameter and biomass growth and biomass partitioning in coniferous trees planted to a recent clearcut site of old growth western red cedar-western hemlock (CH) forest on northern Vancouver Island, British Columbia. Tree species used were western red cedar (Thuja plicata Donn ex D. Don), western hemlock (Tsuga heterophylla

S. X. Chang; G. F. Weetman; C. M. Preston

1996-01-01

100

Dendroclimatic response of mountain hemlock (Tsuga mertensiana ) in Pacific North America Ze'ev Gedalof  

Microsoft Academic Search

In this paper we review the ecology and physiology of mountain is believed to be a reflection of the energy re - quired to mature cones initiated in the preceding year. The association with winter precipitation may reflect the role of deep, persistent snowpacks in regulating the duration of the growing season. Résumé : Dans cet article, les auteurs réexaminent

Dan J. Smith

101

Antioxidant properties of polysaccharides from Ganoderma tsugae  

Microsoft Academic Search

Ganoderma tsugae Murrill (Ganodermataceae) were available in the form of mature and baby Ling chih, mycelia and fermentation filtrate. From these four forms, hot water extracted and hot alkali extracted polysaccharides were prepared and their antioxidant properties were studied. Polysaccharides showed good antioxidant activity as evidenced by their particularly low EC50 values (<0.1mg\\/ml). At 20mg\\/ml, both extracted polysaccharides from mycelia

Yu-Hsiu Tseng; Joan-Hwa Yang; Jeng-Leun Mau

2008-01-01

102

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

USGS Publications Warehouse

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.

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

2002-01-01

103

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Polysilicon), Hemlock, Michigan Pursuant to its authority under...interest; Whereas, the City of Flint, grantee of Foreign-Trade...Corporation, located in Hemlock, Michigan (FTZ Docket 61-2011, filed...Corporation, located in Hemlock, Michigan (Subzone 140C), as...

2013-04-10

104

Poison hemlock ( Conium maculatum L.)  

Microsoft Academic Search

One of the most poisonous species amongst higher plants is Conium maculatum. It is a very common nitrophile weed species, belonging to the Apiaceae (formerly Umbelliferae) family. It contains some piperidine alkaloids (coniine, N-methyl-coniine, conhydrine, pseudoconhydrine, ?-coniceine), which are formed by the cyclisation of an eight-carbon chain derived from four acetate units. ?-Coniceine is the precursor of the other hemlock

J. Vetter

2004-01-01

105

Poison hemlock (Conium maculatum L.).  

PubMed

One of the most poisonous species amongst higher plants is Conium maculatum. It is a very common nitrophile weed species, belonging to the Apiaceae (formerly Umbelliferae) family. It contains some piperidine alkaloids (coniine, N-methyl-coniine, conhydrine, pseudoconhydrine, gamma-coniceine), which are formed by the cyclisation of an eight-carbon chain derived from four acetate units. gamma-Coniceine is the precursor of the other hemlock alkaloids. All vegetative organs, flowers and fruits contain alkaloids. The concentrations (both absolute and relative) of the different alkaloids depend on plant varieties, on ecological conditions and on the age of the plant. The characteristic biological effects of the plants are summarised on cattle, sheep, goat, swine, rabbit, elk, birds and insects and the symptoms of the human toxicosis (some cases of poisonings) are discussed according to the literature data. The general symptoms of hemlock poisoning are effects on nervous system (stimulation followed by paralysis of motor nerve endings and CNS stimulation and later depression), vomiting, trembling, problems in movement, slow and weak later rapid pulse, rapid respiration, salivation, urination, nausea, convulsions, coma and death. PMID:15234067

Vetter, J

2004-09-01

106

Characterization of the Soil Hydromorphic Conditions in a Paludified Dunefield during the Mid-Holocene Hemlock Decline near Québec City, Québec  

NASA Astrophysics Data System (ADS)

The mid-Holocene eastern hemlock [ Tsuga canadensisL. (Carr.)] decline has been recently attributed to the activity of insect defoliators. N. Bihiry and L. Filion, Quaternary Research45,312-320 (1996). In this study, soil hydromorphic conditions were investigated for the period 6800-3200 yr B.P. using micromorphological data from a peat section from a swale in a paludified dunefield in southern Québec. After a short period of plant colonization in shallow pools between 6800 and 6400 yr B.P., mesic conditions predominated in the interdune before the decline (6400-4900 yr B.P.), as evidenced by strong bioturbation and abundance of excrements from the soil fauna. During the decline, a shift from mesic to wet conditions occurred (4900-4100 yr B.P.), although xeric to mesic conditions persisted on dune ridges until at least 4200 yr B.P. Wetness culminated when beaver occupied the site (4100-3750 yr B.P.). Hemlock needles with chewing damage typical of hemlock looper ( Lambdina fiscellaria) feeding were identified at levels dated 4900, 4600, and 4200 yr B.P., respectively, implying that the hemlock decline was associated with at least three defoliation events. The ca. 400-yr interval between these events likely represents the time required for this late-sucessional tree species to recover.

Bhiry, Najat; Filion, Louise

1996-11-01

107

Monoterpene emissions from a Pacific Northwest Old-Growth Forest and impact on regionalbiogenic VOC emission estimates  

Microsoft Academic Search

Measurements of naturalhydrocarbon emission rates are reported for an ol d-growth Pacific Northwest coniferous forest. The emission data were collected for the two dominant species Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) during the growing season in 1997 and 1998 using branch enclosure techniques. Samples were collected at different heights from 13 to 51 m within the canopy using

Shelley Pressley; Brian Lamb; Alex Guenther; Jack Chen; Eugene Allwine

108

Growth reduction in harvest-age, coniferous forests with residual trees in the western central Cascade Range of Oregon  

Microsoft Academic Search

To evaluate the relationship of overstory residual trees to the growth of unmanaged young-to-mature understory Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.), the basal area and volume of 14 paired plots with and without residual trees were examined in the Willamette National Forest, Oregon. Residual trees were large survivors of the fires that initiated

Eric K. Zenner; Steven A. Acker; William H. Emmingham

1998-01-01

109

Factors limiting the early survivorship of Thuja plicata on northern Vancouver Island, British Columbia  

Microsoft Academic Search

Adrian Weber, Benjamin Gilbert, J.P. (Hamish) Kimmins, and C.E. Prescott Abstract: Western redcedar (Thuja plicata Donn ex D. Don), a late successional species on northern Vancouver Island, has a low seedling survival in mature hemlock (Tsuga heterophylla (Raf.) Sarg.) - amabilis fir (Abies amabilis (Dougl. ex Loud.) Dougl. ex J. Forbes) (HA) stands. Shade, moss competition, and substrate were tested

Adrian Weber; Benjamin Gilbert; C. E. Prescott

2003-01-01

110

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...

111

Impacts of the black bear supplemental feeding program on ecology in western  

E-print Network

hemlock (Tsuga heterophylla), and western red cedar (Thuja plicata) after bear damage had spread across the spring appear red as their vigor declines and their needles become discolored. Partially girdled trees carcasses (Cotton 2008, Thiemann et al. 2008). During the spring, they also girdle trees to feed

112

ORIGINAL PAPER What factors influence the stem taper of Eucalyptus  

E-print Network

-011-0012-3 #12;suga menziesii Mirb.), Western hemlock (Tsuga heterophylla (Raf.) Sarg.), and Western red cedar species or to other eucalyptus clones. A sample of 1,623 trees, representing 16 genetically different realized through tree growth. The root mean square error for the over-bark diameter was 7 mm, allowing its

Paris-Sud XI, Université de

113

Historical fires in Douglas-fir dominated riparian forests of the southern Cascades, Oregon  

Microsoft Academic Search

Despite the ecological importance of fire in Pa cific Northwest forests, its role in riparian forests is just beginning to be documented. This study reconstructed the historical occurrence of fire within riparian forests along different stream sizes in coast Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirbel) Franco) dominated forests within the drier western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest series of

Diana L. Olson; James K. Agee

2005-01-01

114

Spatial Relationships between Western Blackheaded Budworm (Acleris gloverana) (Lepidoptera: Tortricidae) Defoliation Patterns and Habitat Zones on Vancouver Island, British Columbia  

Microsoft Academic Search

The western blackheaded budworm (Acleris gloverana (Walshingham)) is a cyclic defoliator of western hemlock (Tsuga heterophylla (Raf.) Sarg.). At least seven blackheaded budworm outbreaks have occurred in British Columbia and severe defoliation has been recorded during five of these outbreaks on Vancouver Island. Spatial patterns of past blackheaded budworm outbreaks on the Island were examined by overlaying them with biogeoclimatic

IMRE S. OTVOS; NEIL BORECKY; ROY F. SHEPHERD; ADAM DEWEY

115

Factors influencing fungal degradation of lignin in a representative lignocellulosic, thermomechanical pulp  

Microsoft Academic Search

This research examined culture parameters influencing the rate of degradation of lignin in lignocellulosic substrates by the Basidiomycete Phanerochaete chryosoprorium. Thermomechanical pulps prepared from western hemlock (Tsuga heterophylla) and red alder (Alnus rubra) were chosen as model substrates. Degradation of lignin in shallow, liquid-phase, stationary cultures was 10 times as rapid as in agitated cultures. Lignin degradation was at least

H. H. Yang; M. J. Effland; T. K. Kirk

1980-01-01

116

DEMOGRAPHY OF THE PRINCE OF WALES FLYING SQUIRREL, AN ENDEMIC OF SOUTHEASTERN ALASKA TEMPERATE RAIN FOREST  

Microsoft Academic Search

We studied the Prince of Wales flying squirrel ( Glaucomys sabrinus griseifrons ) in tem- perate rain forest of southeastern Alaska to provide the 1st quantitative estimates of de- mography from southeastern Alaska and test predictions of the hypothesis that Sitka spruce (Picea sitchensis)-western hemlock (Tsuga heterophylla) forest is primary habitat for G. sabrinus in southeastern Alaska. We expected that

WINSTON P. S MITH; JEFFREY V. N ICHOLS

2003-01-01

117

Windthrow Disturbance, Forest Composition, and Structure in the Bull Run Basin, Oregon  

Microsoft Academic Search

This study examined relationships among forest landscape dynamics, envi- ronmental factors (climate and landforms), and disturbance history in forests dominated by Douglas-fir (Pseudotsuga menziesii), western hemlock (Tsuga heterophylla), and Pacific silver fir (Abies amabilis) in the Bull Run basin in northwestern Oregon and evaluated the findings in a broader geographic context. Three sets of analyses were conducted: mapping of historical

Diana S. Sinton; Julia A. Jones; Janet L. Ohmann; Frederick J. Swanson

2000-01-01

118

A Novel Extractant for Removal of Hazardous Metals from Preservative-Treated Wood Waste  

Microsoft Academic Search

The purpose of this study was to develop a one-step metal ex- traction process that would effectively remove hazardous elements from wood powder or chips of western hemlock (Tsuga heterophylla (Raf.) Sarg.) treated with chromated copper arsenate (CCA) preser- vative. In addition, we tested this method for wood treated with other copper-based preservatives such as ammoniacal copper quaternary (ACQ) and

Tomo Kakitani; Toshimitsu Hata; Takeshi Kajimoto; Yuji Imamura

2006-01-01

119

The phytotoxic effect of exogenous ethanol on Euphorbia heterophylla L.  

PubMed

This study investigated the effects of exogenously applied ethanol on Euphorbia heterophylla L., a troublesome weed in field and plantation crops. Ethanol at concentrations ranging from 0.25 to 1.5% caused a dose-dependent inhibition of germination and growth of E. heterophylla. Measurements of respiratory activity and alcohol dehydrogenase (E.C. 1.1.1.1) activity during seed imbibition and initial seedling growth revealed that ethanol induces a prolongation of hypoxic conditions in the growing tissues. In isolated mitochondria, ethanol inhibited the respiration coupled to ADP phosphorylation, an action that probably contributed to modifications observed in the respiratory activity of embryos. A comparison of the effects of methanol, ethanol, propanol and acetaldehyde on germination and growth of E. heterophylla indicates that alcohol dehydrogenase activity is required for the observed effects, with the conversion of ethanol to acetaldehyde playing a role in the ethanol-induced injuries. PMID:19640725

Kern, Kátia Aparecida; Pergo, Erica Marusa; Kagami, Fernanda Lima; Arraes, Luis Saraiva; Sert, Maria Aparecida; Ishii-Iwamoto, Emy Luiza

2009-01-01

120

Antioxidant and radical scavenging properties of extracts from Ganoderma tsugae  

Microsoft Academic Search

The antioxidant activities and scavenging effects on free radicals of extracts from Ganoderma were investigated. The methanolic extracts of Ganoderma tsugae (MEGT) showed the strongest antioxidant activity of five species of Ganoderma tested. MEGT exhibited substantial antioxidant activity in the linoleic acid and rat liver microsome peroxidation systems. The antioxidant activity of MEGT was stronger than ?-tocopherol. MEGT had a

Gow-Chin Yen; Jun-Yi Wu

1999-01-01

121

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)

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.

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

2012-12-01

122

Hemlock alkaloids from Socrates to poison aloes  

Microsoft Academic Search

Hemlock (Conium maculatum L. Umbelliferae) has long been known as a poisonous plant. Toxicity is due to a group of piperidine alkaloids of which the representative members are coniine and ?-coniceine. The latter is the more toxic and is the first formed biosynthetically. Its levels in relation to coniine vary widely according to environmental conditions and to provenance of the

Tom Reynolds

2005-01-01

123

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

PubMed

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

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

2015-01-01

124

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

PubMed Central

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

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

2015-01-01

125

Antioxidant properties of hot water extracts from Ganoderma tsugae Murrill  

Microsoft Academic Search

Ganoderma tsugae Murrill (Ganodermataceae) were available in the form of mature and baby Ling chih, mycelia and fermentation filtrate. From these four forms, hot water extracts were prepared and their antioxidant properties were studied. Hot water extracts from mature and baby Ling chih showed high antioxidant activities (78.5% and 78.2%) at 20mg\\/ml, and had EC50 values of 7.25 and 5.89mgextract\\/ml,

Jeng-Leun Mau; Shu-Yao Tsai; Yu-Hsiu Tseng; Shih-Jeng Huang

2005-01-01

126

Efficacy of Foliar Applications, Trunk Injections, and Soil Drenches in Reducing Populations of Elongate Hemlock Scale on Eastern Hemlock  

Microsoft Academic Search

We examined the efficacy of two approaches for controlling elongate hemlock scale on eastern hemlocks in an arboretum. One approach relied on foliar applications of an insect growth regulator, pyriproxyfen, and horticultural spray oil when crawlers were abundant. The second approach evaluated soil drenches and trunk injections of the systemic insecticides imida- cloprid, dinotefuron, and acephate. Foliar applications of pyriproxyfen

Michael Raupp; Robert Ahern; Brad Onken; Richard Reardon; Stacey Bealmear; Joseph Doccola; Paul Wolfe II; Peter Becker

2008-01-01

127

Convective Drying of Ganoderma tsugae Murrill and Effect of Temperature on Basidiospores  

Microsoft Academic Search

In this study, drying of Ganoderma tsugae Murrill slices was carried out at different temperatures in a hot air circulating oven. The objectives were to investigate the drying characteristic and drying kinetics of the Ganoderma slices under constant air velocity and slice thickness. In addition, the effect of drying temperatures on the size and surface structure of Ganoderma tsugae basidiospores

Siew Kian Chin; Chung Lim Law; Christina Vimala Supramaniam; Poh Guat Cheng; Arun S. Mujumdar

2008-01-01

128

FIRST REPORT OF THE RUST MELAMPSORA EUPHORBIAE ON EUPHORBIA HETEROPHYLLA IN OMAN  

Technology Transfer Automated Retrieval System (TEKTRAN)

Euphorbia heterophylla L. or painted spurge or is a serious weed in many parts of the world and considerable efforts have been made to limit its invasiveness and impact on crop productivity. This has included evaluation of fungi as biocontrol agents. In Oman, E. heterophylla is a rare, introduced ...

129

Chemical and biological investigation of Araucaria heterophylla Salisb. resin.  

PubMed

Three labdane diterpenes, namely lambda-8(17),14-diene, 13-epicupressic acid, and 13-Oacetyl-13-epicupressic acid, were isolated from the resin collected from stem exudates of Araucaria heterophylla Salisb. (Araucariaceae). The isolated compounds were identified using different spectroscopic methods (1H NMR, 13C NMR, HMQC, HMBC and COSY). The resin extract showed antiulcerogenic activity against ethanol-induced stomach ulcers in Sprauge Dawely rats using ranitidine as standard. In addition, the resin and the isolated compounds showed variable cytotoxic activities against breast (MCF7) and colon (HCT116) cancer cell lines. PMID:20158152

Abdel-Sattar, Essam; Monem, Azza R Abdel; Ezzat, Shahira M; El-Halawany, Ali M; Mouneir, Samar M

2009-01-01

130

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 ...

131

Monoterpene emissions from a Pacific Northwest Old-Growth Forest and impact on regional biogenic VOC emission estimates  

Microsoft Academic Search

Measurements of natural hydrocarbon emission rates are reported for an old-growth Pacific Northwest coniferous forest. The emission data were collected for the two dominant species Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) during the growing season in 1997 and 1998 using branch enclosure techniques. Samples were collected at different heights from 13 to 51m within the canopy using the

Shelley Pressley; Brian Lamb; Hal Westberg; Alex Guenther; Jack Chen; Eugene Allwine

2004-01-01

132

Is soil respiration a major contributor to the carbon budget within a Pacific Northwest old-growth forest?  

Microsoft Academic Search

Carbon dioxide (CO2) exchange was measured above the forest floor of a temperate Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) and Western Hemlock (Tsuga heterophylla (Raf.) Sarg.) old-growth forest in southern Washington State. Continuous flux measurements were conducted from July 1998 to December 2003 using the eddy-covariance technique. Maximum observed fluxes were +6?molm?2s?1 on a monthly average in summer decreasing to +1

Matthias Falk; Kyaw Tha Paw U; Sonia Wharton; Matt Schroeder

2005-01-01

133

Estimated persistence of northern flying squirrel populations in temperate rain forest fragments of Southeast Alaska  

Microsoft Academic Search

Habitat reserves are a common strategy used to ensure viability of wildlife populations and communities. The efficacy of reserves, however, is rarely empirically evaluated. We examined the likelihood that small (650 ha), isolated habitat reserves composed of old-growth Sitka spruce (Picea sitchensis)–western hemlock (Tsuga heterophylla) rain forest (upland-OG) and mixed-conifer peatlands (peatland-MC) would sustain populations of northern flying squirrels (Glaucomys

Winston P. Smith; David K. Person

2007-01-01

134

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

PubMed Central

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

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

2009-01-01

135

Decomposing the mid-Holocene Tsuga decline in eastern North America.  

PubMed

The mid-Holocene decline of Tsuga canadensis (hereafter Tsuga) populations across eastern North America is widely perceived as a synchronous event, driven by pests/pathogens, rapid climate change, or both. Pattern identification and causal attribution are hampered by low stratigraphic density of pollen-sampling and radiometric dates at most sites, and by absence of highly resolved, paired pollen and paleoclimate records from single sediment cores, where chronological order of climatic and vegetational changes can be assessed. We present an intensely sampled (contiguous 1-cm intervals) record of pollen and water table depth (inferred from testate amoebae) from a single core spanning the Tsuga decline at Irwin Smith Bog in Lower Michigan, with high-precision chronology. We also present an intensively sampled pollen record from Tower Lake in Upper Michigan. Both sites show high-magnitude fluctuations in Tsuga pollen percentages during the pre-decline maximum. The terminal decline is dated at both sites ca. 5000 cal yr BP, some 400 years later than estimates from other sites and data compilations. The terminal Tsuga decline was evidently heterochronous across its range. A transient decline ca. 5350 cal yr BP at both sites may correspond to the terminal decline at other sites in eastern North America. At Irwin Smith Bog, the terminal Tsuga decline preceded an abrupt and persistent decline in water table depths by approximately 200 years, suggesting the decline was not directly driven by abrupt climate change. The Tsuga decline may best be viewed as comprising at least three phases: a long-duration pre-decline maximum with high-magnitude and high-frequency fluctuations, followed by a terminal decline at individual sites, followed in turn by two millennia of persistently low Tsuga populations. These phases may not be causally linked, and may represent dynamics taking place at multiple temporal and spatial scales. Further progress toward understanding the phenomenon requires an expanded network of high-resolution pollen and paleoclimate chronologies. PMID:22928413

Booth, Robert K; Brewer, Simon; Blaauw, Maarten; Minckley, Thomas A; Jackson, Stephen T

2012-08-01

136

Hemlock woolly adelgid impacts on community structure and N cycling rates in eastern  

E-print Network

canadensis (L.) Carr.) forests in southern New England. Data were collected at six hemlock-dominated sites (Murr.) Barr.), beech bark disease (Cryptococcus fagisuga Lind. and Nectria spp.), and the hemlock

137

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

Federal Register 2010, 2011, 2012, 2013, 2014

...61-2011] Foreign-Trade Zone 140--Flint, Michigan; Application for Subzone; Hemlock...Board (the Board) by the City of Flint, grantee of FTZ 140, requesting...Corporation (HSC), located in Hemlock, Michigan. The application was...

2011-10-12

138

Poison hemlock, Conium maculatum, (Figure 1) is a member of the plant  

E-print Network

plant com- munities in riparian woodlands, flood- plains of natural aquatic systems, and grazing areas Pest Management for Land Managers Poison Hemlock Figure 2. Distribution of poison hemlock in California Publication 74162 Figure 1. Mature poison hemlock. Figure 3. Seed leaves and first true leaves of poison

Ishida, Yuko

139

Toxicoses in livestock from the hemlocks (Conium and Cicuta spp.).  

PubMed

The hemlocks, Conium maculatum (poison-hemlock) and Cicuta spp. (waterhemlock), are poisonous plants that cause sizeable losss to the livestock industry. Clinical signs of poisonhemlock toxicosis are similar in all species of livestock and include muscular weakness, incordination, trembling, initial central nervous system stimulation, depression and death from respiratory paralysis. Poison-hemlock also causes skeletal defects in the offspring of cattle, pigs and sheep and cleft palate in pigs when ingested during specific periods of gestation. The primary toxicants in poison-hemlock are coniine and gamma-coniceine. Coniine predominates in mature plants and seed, whereas gamma-coniceine predominates in early growth of the plant. Waterhemlock is the most violently toxic poisonous plant known. The toxicant is cicutoxin, which acts on the central nervous system, causing violent convulsions and death. Clinical signs of poisoning appear within 15 min after ingestion of a lethal dose and include excessive salivation, nervousness, tremors, muscular weakness and convulsive seizures interspersed by intermittent periods of relaxation and a final paralytic seizure resulting in anoxia and death. Elevated activities of lactic dehydrogenase, aspartate aminotransferase and creatine kinase in blood are observed, indicative of muscular damage. Toxicoses from poisonhemlock and waterhemlock generally occur in early spring when both plants emerge before other, more palatable plants begin to grow. All parts of the poison-hemlock plant are toxic. The root or tubers of waterhemlock are toxic; however, experimental evidence concerning the toxicity of other plant parts is inconclusive. PMID:3049497

Panter, K E; Keeler, R F; Baker, D C

1988-09-01

140

Hemlock alkaloids from Socrates to poison aloes.  

PubMed

Hemlock (Conium maculatum L. Umbelliferae) has long been known as a poisonous plant. Toxicity is due to a group of piperidine alkaloids of which the representative members are coniine and gamma-coniceine. The latter is the more toxic and is the first formed biosynthetically. Its levels in relation to coniine vary widely according to environmental conditions and to provenance of the plants. Surprisingly, these piperidine alkaloids have turned up in quite unrelated species in the monocotyledons as well as the dicotyledons. Aloes, for instance, important medicinal plants, are not regarded as poisonous although some species are very bitter. Nevertheless a small number of mostly local species contain the alkaloids, especially gamma-coniceine and there have been records of human poisoning. The compounds are recognized by their characteristic mousy smell. Both acute and chronic symptoms have been described. The compounds are neurotoxins and death results from respiratory failure, recalling the effects of curare. Chronic non-lethal ingestion by pregnant livestock leads to foetal malformation. Both acute and chronic toxicity are seen with stock in damp meadows and have been recorded as problems especially in North America. The alkaloids derive biosynthetically from acetate units via the polyketide pathway in contrast to other piperidine alkaloids which derive from lysine. PMID:15955542

Reynolds, Tom

2005-06-01

141

Western Hemlock Looper and Disturbance in ICH Forests  

E-print Network

Hemlock zone (Meidinger et al. 1991) of the Robson Valley since 1950 (Parfett, Otvos and Van Sickle 1995 39 000 ha, mostly between 1991-92 (Taylor unpublished). Existing studies have mainly focussed. A study was initiated in 1998 to investigate the impacts of WHL on forests in wetter sub- zones of the ICH

Northern British Columbia, University of

142

Spatial Relationship of Biomass and Species Distribution in an Old-Growth  

E-print Network

analysis for Tsuga heterophylla, Abies amabilis, A. grandis, Pseudotsuga menziesii, Thuja plicata characterized by high proportions of T. heterophylla and T. plicata depending on spatial locations across

Song, Bo

143

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

PubMed

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 ?m with a number-mean diameter of 0.11 ?m. There were about 62% particles smaller than 0.1 ?m in terms of number of particles. Scanning electron microscopy (SEM) confirmed the presence of particles at nano/submicrometer scale. The content of 1?3-?-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

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

2014-12-17

144

Drought resistance of two Douglas fir species (Pseudo-tsuga menziesii (Mirb.) Franco and Pseudotsuga macro-  

E-print Network

Drought resistance of two Douglas fir species (Pseudo- tsuga menziesii (Mirb.) Franco shortage, it is important to determine which physiological compo- nents may be involved in their drought drought, a dra- matic decline of mesophyll photosynthesis was noted starting from -1.5 MPa in P

Paris-Sud XI, Université de

145

American Journal of Botany 90(4): 610619. 2003. STOMATAL FREQUENCY ADJUSTMENT OF FOUR  

E-print Network

American conifer species (Tsuga heterophylla, Picea glauca, Picea mariana, and Larix laricina) to a range with a high preservation capacity, fossil needles of Tsuga heterophylla, Picea glauca, P. mariana, and Larix

Cochran-Stafira, D. Liane

146

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

PubMed

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 Réunion 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. 18 000 km 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

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

2014-10-01

147

Effect of temperature and host tree on cold hardiness of hemlock looper eggs along a latitudinal gradient  

Microsoft Academic Search

The hemlock looper, Lambdina fiscellaria, is an economically important insect pest of Canadian forests which overwinters as eggs. Although the hemlock looper causes extensive damages, no information on the mechanisms related to its cold tolerance is known. The objective of this study was to determine the effect of temperature and exposure duration on hemlock looper winter survival but also to

Sophie Rochefort; Richard Berthiaume; Christian Hébert; Martin Charest; Éric Bauce

2011-01-01

148

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

Technology Transfer Automated Retrieval System (TEKTRAN)

Immature water hemlock seed heads caused the death of 9 cows in a herd of 81 in central Utah. This is the first documented case of poisoning and death in cattle from ingesting immature water hemlock seed. Field investigation of the poisoning and follow up diagnostic, chemical and toxicological eva...

149

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

Microsoft Academic Search

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.

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

2011-01-01

150

www.btny.purdue.edu/weedscience/ Poison Hemlock The Toxic Parsnip  

E-print Network

as soon as possible. Large doses of mineral oil and purgatives are also prescribed to empty the digestivewww.btny.purdue.edu/weedscience/ Poison Hemlock ­ The Toxic Parsnip We often get questions about (Conium maculatum L.). Although these two plants may look similar, poison hemlock is toxic to cattle

Ginzel, Matthew

151

Structure and antitumor activities of the water-soluble polysaccharides from Ganoderma tsugae mycelium  

Microsoft Academic Search

Six water-soluble polysaccharides coded as GTM1 to GTM6 were extracted sequentially from the mycelium of Ganoderma tsugae with 0.2M sodium phosphate buffer solution at 25, 40, and 80°C, water at 120°C, 0.5M sodium hydroxide at 25 and 65°C. The chemical structures were determined by using IR, EA, GC and 13C NMR. The weight-average molecular mass (Mw) was characterized by size

Yanfei Peng; Lina Zhang; Fanbo Zeng; John F. Kennedy

2005-01-01

152

A fatal case of apparent water hemlock poisoning.  

PubMed

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

Heath, K B

2001-02-01

153

Poison hemlock-induced respiratory failure in a toddler.  

PubMed

The ingestion of poison hemlock, or Conium maculatum, is described in a 2-year-old boy. He had the onset of abdominal pain and weakness after being fed C. maculatum picked by his sister from the roadside 2 hours earlier. He had a rapidly progressive muscular weakness and was intubated for respiratory failure. His symptoms completely resolved within 24 hours of the ingestion. Conium maculatum is a common weed that causes toxicity by its primary toxin, coniine, which stimulates nicotinic receptors and causes a syndrome of rapidly progressive muscle weakness and paralysis. We describe the course of a benign-appearing plant ingestion resulting in respiratory failure. PMID:19915429

West, Patrick L; Horowitz, B Zane; Montanaro, Marc T; Lindsay, James N

2009-11-01

154

[Study on seed quality test and quality standard of Pesudostellaria heterophylla].  

PubMed

Referring to the rules for agricultural seed testing (GB /T 3543-1995) issued by China, the test of sampling, seed purity, weight per 1 000 seeds, seed moisture, seed viability and germination rate had been studied for screening seed quality test methods of Pesudostellaria heterophylla. The seed quality from different collection areas was measured. The results showed that at least 6.5 g seeds should be sampled and passed through 10-mesh sieve for purity analysis. The weight of 1 000 seeds was determined by using the 500-seed method. The phenotypic observation and size measurement were used for authenticity testing. The seed moisture was determined under the higher temperature (130 ± 2) degrees C for 5 hours. The seeds were dipped into 0.2% TTC sustaining 1 hour at 40 degrees C, then the viability could be determined. The break dormancy seeds were cultured on sand at 10 degrees C. K cluster analysis was applied for the data analysis, the seed quality from different collection areas grading of P. Heterophylla was described as three grades. The seed quality of each grade should reach following requirements: for first grade seeds, germination rate ? 86%, 1 000-grain weight ? 2.59 g, purity ? 87%, moisture ? 13.1%; for second grade seeds, germination rate ? 70%, 1 000-grain weight ? 2.40 g, purity ? 77%, moisture ? 14.3%; for third grade seeds, germination rate ? 41%, 1 000-grain weight ? 2.29 g, purity ? 76%, moisture ? 15.8%. The seed testing methods for quality items of P. heterophylla had been initially established, as well as the primary P. heterophylla seed quality classification standard. PMID:25509284

Xiao, Cheng-Hong; Zhou, Tao; Jiang, Wei-Ke; Chen, Min; Xiong, Hou-Xi; Liao, Ming-Wu

2014-08-01

155

Potential use of leaf biomass, Araucaria heterophylla for removal of Pb+2.  

PubMed

The present investigation attempt to analyze the biosorption behavior of novel biosorbent, Araucaria heterophylla (green plant) biomass, for removal of Pb(+2) from solution as the function of initial metal ion concentration, pH, temperature, sorbent dosage and biomass particle size. The maximum biosorption was found to be 95.12% at pH 5 and biosorption capacity (q(e)) of Cd(+2) is 9.643 mg/g. The Langmuir and Freundlich equilibrium adsorption isotherms were studied and observed that Freundlich model is best fit than the Langmuir model with correlation coefficient of 0.9927. Kinetic studies indicated that the biosorption process of Cd(+2) followed well pseudo second order model with R2 0.999. The process is exothermic and, spontaneous. The chemical functional groups -OH, CH2 stretching vibrations, C=O of alcohol, C=O of amide, P=O stretching vibrations, -CH, were involved in the process. The XRD pattern of the A. heterophylla was found to be mostly amorphous in nature. The SEM studies showed Pb(+2) biosorption on selective grains of the biosorbent. It was concluded that A. heterophylla leaf powder can be used as an effective, low cost, and environmentally friendly biosorbent for the removal of Pb(+2) from aqueous solution. PMID:23819273

Sarada, B; Prasad, M Krishna; Kumar, K Kishore; Murthy, Ch V R

2013-01-01

156

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

PubMed Central

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

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

2014-01-01

157

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

PubMed Central

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

2014-01-01

158

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

PubMed

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 m(3)/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

Woods, Kerry D

2014-01-01

159

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

NASA Astrophysics Data System (ADS)

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.

Williams, Justin P.

160

Proceedings of the Sudden Oak Death Fifth Science Symposium Susceptibility of Larch, Hemlock, Sitka Spruce, and  

E-print Network

on Japanese larch (Larix kaempferi (Lam.) Carrière) in the United Kingdom (Forestry Commission 2012, Webber et. laricina (Du Roi) K. Koch), and western larch (L. occidentalis Nutt.); western and eastern hemlock (T

Standiford, Richard B.

161

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Environmental Assessment for a Biological Control Agent for Hemlock Woolly Adelgid...United States for use as a biological control agent to reduce the severity...United States for use as a biological control agent to reduce the...

2010-05-20

162

Detection of wet-pockets in hemlock using, near infrared spectroscopy  

Microsoft Academic Search

The objective of this preliminary study was to assess and develop a method of detecting the presence of wet-pockets in hemlock lamina based on near infrared (NIR) spectroscopy. Three principal component regression models with different pre-processing methods capable of predicting moisture content of hemlock within the accuracy limits of the calibration models were developed. The pre-processing of data to the

F. Hart; S. Avramidis; S. Mansfield

163

Conium maculatum (poison hemlock) toxicosis in a flock of range turkeys.  

PubMed

Five 20-week-old tom turkeys from a flock of range turkeys were presented for examination; the flock had a history of salivation, tremors, paralysis, and increased mortality. Necropsy revealed numerous seeds identified as seeds from Conium maculatum (poison hemlock) within the crop, proventriculus, and gizzard. Histopathologic alterations were limited to catarrhal enteritis. Clinical signs of Conium maculatum toxicosis abated after the turkeys were removed from their range, which was infested with poison hemlock. PMID:3619833

Frank, A A; Reed, W M

1987-01-01

164

Inclination distributions and size measurements of hemlock and red spruce needles  

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

165

Highly stocked coniferous stands on the Olympic Peninsula: chemical composition and implications for harvest strategy. Forest Service research paper  

SciTech Connect

This report presents an assessment of macronutrients and their distribution within highly stocked, stagnant stands of mixed conifers on the Quilcene Ranger District, Olympic National Forest, northwest Washington. These stands consisted of predominantly three species: western hemlock (Tsuga heterophylla), coast Douglas-fir (Pseudotsuga menzeisii), and western redcedar (Thuja plicata). Preliminary investigation suggests that the living crown contains a small portion of the nutrient capital on the site. Extracting this material from the site during harvest or site preparation should not pose a threat to future production of biomass. Bioassays suggested that no macronutrients were deficient for growth of Douglas-fir seedlings.

Little, S.N.; Waddell, D.R.

1987-10-01

166

The impact of hemlock looper ( Lambdina fiscellaria fiscellaria (Guen.)) on balsam fir and spruce in New Brunswick, Canada  

Microsoft Academic Search

In 1989, the first recorded outbreak of hemlock looper (Lambdina fiscellaria fiscellaria (Guen.)) occurred in New Brunswick, Canada. Data were collected from ten plots established in an area infested from 1992–1994, to assess impacts of hemlock looper. Ocular and branch sample assessments of current defoliation and ocular assessments of total defoliation (all age classes of foliage) were conducted for balsam

David A MacLean; Paul Ebert

1999-01-01

167

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...

168

Effect of temperature and host tree on cold hardiness of hemlock looper eggs along a latitudinal gradient.  

PubMed

The hemlock looper, Lambdina fiscellaria, is an economically important insect pest of Canadian forests which overwinters as eggs. Although the hemlock looper causes extensive damages, no information on the mechanisms related to its cold tolerance is known. The objective of this study was to determine the effect of temperature and exposure duration on hemlock looper winter survival but also to identify seasonal supercooling capacity and cryoprotectant levels of three populations along a latitudinal gradient. As host plant may contribute to offspring overwintering success, cold tolerance of hemlock looper eggs from parents whose larvae were fed on three different tree species was also measured. Mean supercooling point (SCP) of hemlock looper eggs was lower than -30 °C from October through the following spring with values being as low as -47 °C in February. Trehalose was the most abundant sugar found in hemlock looper eggs with a peak concentration of 0.3 ?g mg?¹ DW?¹. Glycerol, a polyol, was more often absent in eggs of the different populations and tree species tested in the study. When exposed to different temperature regimes for various periods of time, significant mortality of hemlock looper eggs occurred at higher temperatures than the mean SCP. Thus, hemlock looper could be considered as a chill tolerant species. No clear pattern of population and host plant effects on SCP and cryoprotectants was detected in this study. However, when exposed to different winter temperatures and exposure duration, hemlock looper from higher latitudes survived better (survival rates ranging between 0 and 89% at -20 °C) than those from lower latitudes (survival rates ranging between 0 and 56% at -20 °C). Our results may contribute to a better understanding of hemlock looper winter biology and thus facilitate predictions of outbreaks and range expansion. PMID:21356214

Rochefort, Sophie; Berthiaume, Richard; Hébert, Christian; Charest, Martin; Bauce, Eric

2011-06-01

169

Aluminum, Fe, Ca, Mg, K, Mn, Cu, Zn and P in above- and belowground biomass. I. Abies amabilis and Tsuga mertensiana  

Microsoft Academic Search

In a mature mixed subalpine stand ofTsuga mertensiana andAbies amabilis, significantly higher Al levels were found in foliage, branch and root tissues ofT. mertensiana.Tsuga mertensiana had significant increases in Al, Ca and Mn levels with increasing foliage age. In current foliage,T. mertensiana had lower levels of Ca, similar levels of Mg and P, and higher levels of Mn thanA. amabilis.

K. A. Vogt; R. Dahlgren; F. Ugolini; D. Zabowski; E. E. Moore; R. Zasoski

1987-01-01

170

Hypoglycemic effect of polysaccharides with different molecular weight of Pseudostellaria heterophylla  

PubMed Central

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-1?, IL-2, IL-10, Leptin, TNF-?, 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-? 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

2013-01-01

171

Phenology, natural enemies, and efficacy of horticultural oil for control of Chionaspis heterophyllae (Homoptera: Diaspididae) on Christmas tree plantations.  

PubMed

Pine needle scale, Chionaspis pinifoliae (Fitch), and Chionaspis heterophyllae Cooley are important pests of Scots pine, Pinus sylvestris L., and other conifers in much of North America. On Christmas tree plantations, these insects are typically controlled by spraying broad-spectrum insecticides when the vulnerable immature stages are present. However, effective control of bivoltine populations can be difficult to achieve due to asynchronous hatch and development of the second generation. Our objectives were to 1) determine the phenology of the second generation of C. heterophyllae in Michigan; 2) characterize the natural enemy complex; and 3) assess the effectiveness of horticultural oil for control of C. heterophyllae on P. sylvestris Christmas tree plantations. We monitored scale populations in three counties in lower Michigan for 3 yr. Scale phenology was consistently associated with cumulative degree-days base 10 degrees C (DD(10 degrees C)). Second-generation egg hatch began at approximately 1230-1300 DD(10 degrees C), and continued for approximately 3 wk. The peak of the second instar coincided with 1500-1600 DD(10 degrees C). Common predators included the coccinellids Chilocorus stigma (Say) and Microweisia misella (LeConte). On average, 70% of the C. heterophyllae population in unsprayed fields was killed by predators in 1999. Two endoparasitic wasps, Encarsia bella Gahan and Marietta mexicana Howard (Hymenoptera: Aphelinidae), also were recovered. In 2000 and 2001, we applied a highly refined horticultural spray oil with a backpack mist blower at 1500-1600 DD(10 degrees). Scale mortality on trees treated with oil ranged from 66 to 80% and was similar to control achieved using conventional insecticides in both years. PMID:16334330

Fondren, Kirsten M; McCullough, Deborah G

2005-10-01

172

Fungal pathogens of Euphorbia heterophylla and E. hirta in Brazil and their potential as weed biocontrol agents  

Microsoft Academic Search

A two-year survey of the fungi associated with two important congeneric pantropical weeds, Euphorbia heterophylla and E. hirta, was conducted in part of their native range in southern Brazil. Sampling was concentrated mainly in Rio de Janeiro State\\u000a and ten species were identified as pathogens of these weeds. Two taxa, Botrytis ricini and Uromyces euphorbiae, were common to both weed

Robert W. Barreto; Harry C. Evans

1998-01-01

173

THE ECONOMIC IMPACTS OF HEMLOCK WOOLLY ADELGID ON RESIDENTIAL LANDSCAPE VALUES: SPARTA, NEW JERSEY CASE STUDY  

Microsoft Academic Search

In this paper, we provide preliminary estimates of the impacts of the hemlock woolly adelgid on residential property values in Sparta, New Jersey, using the hedonic property value method. The literature on the aesthetic perceptions of forest landscapes is briefly reviewed to provide guidance in formulating economic hypotheses based on the assumption of an informative relationship between forest aesthetics and

Thomas P. Holmes; Elizabeth A. Murphy; Denise D. Royle

174

Original Contribution INTOXICATION WITH POISON HEMLOCK (CONIUM MACULATUM L.) IN CALVES  

Microsoft Academic Search

The case of spontaneous poisoning of 38 calves with Poison Hemlock (Conium maculatum) was described. The following indices were measured, among others: haemoglobin content (HGB), red blood cell counts (RBC), white blood cell counts (WBC), haematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), differential white cell counts (DWC), erythrocyte sedimentation rate (ESR), etc.

R. Binev; J. Mitev; T. Miteva

2007-01-01

175

Mid-Holocene hemlock decline and diatom communities in van Nostrand Lake, Ontario, Canada  

Microsoft Academic Search

Terrestrial ecosystem disturbances inferred from the fossil hemlock pollen decline (ca. 4,800 BP) and recovery (ca. 3,800 BP) affected van Nostrand Lake including the diatom communities. Ecological models suggest the lake responded by eutrophying, reflecting higher nutrient influx resulting from increased erosion. A decline in lake productivity followed as the forest vegetation recovered and erosion slowed. Lastly, as the forest

Marianne S. V. Douglas; J. H. McAndrews

2000-01-01

176

Modeling insecticide protection versus forest management approaches to reducing balsam fir sawfly and hemlock looper damage  

Microsoft Academic Search

A decision support system (DSS) for improved management decision making and to reduce impacts of forest insect outbreaks was developed and implemented for two defoliators, hemlock looper (Lambdina fiscellaria fiscellaria Guen.) and balsam fir sawfly (Neodiprion abietis Harris), in District 15, a 336,805ha forest managed by Corner Brook Pulp and Paper Ltd. in western Newfoundland, Canada. Over the past 15years,

Javed Iqbal; Chris R. Hennigar; David A. MacLean

177

Forest roadside sampling of larvae and adults of the western hemlock looper, Lambdina fiscellaria lugubrosa  

Microsoft Academic Search

The roadside sampling method, in which sampling is conducted along a road has the advantage that large areas can be quickly surveyed. The method is particularly useful for forest areas where accessibility to trees within a stand can be a problem. In this study, larvae and adults of the western hemlock looper were sampled along forest roads and the data

Qiwei Liang; Imre S. Otvos; Gary E. Bradfield

1997-01-01

178

Coarse-Scale Hazard Rating of Western Hemlock Looper in British Columbia  

Microsoft Academic Search

The western hemlock looper (Lambdina fiscellaria lugubrosa (Hulst.)) is a serious defoliating pest in western North America. During the 1990-1995 outbreak, this pest was responsible for approximately 63 000 ha of stand mortality in British Columbia. There have been 14 distinct outbreaks, increasing in duration and severity over the past 87 years. Outbreaks tend to occur in Coastal and Interior

NEIL BORECKY; IMRE S. OTVOS

179

Mid-Holocene hemlock decline and diatom communities in van Nostrand Lake, Ontario, Canada  

Microsoft Academic Search

Terrestrial ecosystem disturbances inferred from the fossil hemlock pollen decline (ca. 4,800 BP) and recovery (ca. 3,800 BP) affected van Nostrand Lake, including the diatom communities. Ecological models suggest the lake responded by eutrophying, reflecting higher nutrient influx resulting from increased erosion. A decline in lake productivity followed as the forest vegetation recovered and erosion slowed. Lastly, as the forest

Jeannine-Marie St. Jacques; Marianne S. V. Douglas; J. H. McAndrews

2000-01-01

180

Assessment of Neonectria neomacrospora (anamorph Cylindrocarpon cylindroides) as an inundative biocontrol agent against hemlock dwarf mistletoe  

Microsoft Academic Search

A field trial was conducted on Vancouver Island to evaluate the efficacy of the native fungus Neonectria neomacrospora as a biocontrol agent of hemlock dwarf mistletoe (Arceuthobium tsugense), a conifer parasite. Treatments consisted in formulated inoculum of N. neomacrospora applied to unwounded and wounded A. tsugense swellings. After 10 months, the amount of bark necrosis for the wounded, inoculated treatment

Lea M. Rietman; Bart J. van der Kamp; Simon F. Shamoun

2005-01-01

181

A neighborhood analysis of canopy tree competition: effects of shading versus crowding  

E-print Network

heterophylla (Raf.) Sarg.) and western redcedar (Thuja plicata Donn ex D. Don). For both species, the most-Britannique dominées par la pruche de l'Ouest (Tsuga heterophylla (Raf.) Sarg.) et le thuya géant (Thuja pli- cata Donn

182

Chirality of 5,11-dimethylheptadecane, the major sex pheromone component of the hemlock looper, Lambdina fiscellaria (Lepidoptera: Geometridae)  

Microsoft Academic Search

Of the four possible stereoisomers of 5,11-dimethylheptadecane, the major sex pheromone component of the eastern hemlock looper (EHL),Lambdina fiscellaria fiscellaria Guen., and the western hemlock looper (WHL),Lambdina fiscellaria lugubrosa Hulst, (5R,11S)-5,11-dimethylheptadecane was the only stereoisomer eliciting electrophysiological responses by male EHL and WHL antennae. In field bioassays with EHL and WHL populations, traps baited with (5R,11S)-5, 11-dimethylheptadecane caught as many

Li Jianxiong; R. Gries; G. Gries; K. N. Slessor; G. G. S. King; W. W. Bowers; R. J. West

1993-01-01

183

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

NASA Astrophysics Data System (ADS)

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.

Filion, Louise; Quinty, François

1993-07-01

184

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

PubMed

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

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

2011-01-01

185

Why mechanisms should be in the eye of the beholder  

E-print Network

ponderosa Pinus contorta #12;Foliage Stem Roots Ecosystem models (production ecology context) Trees = bins) Depthintocrown(m) Tsuga heterophylla Larix decidua x leptolepis Pseudotsuga menziesii Abies grandis Pinus

186

Congenital skeletal malformations induced by maternal ingestion of Conium maculatum (poison hemlock) in newborn pigs.  

PubMed

Skeletal malformations were induced in newborn pigs from gilts fed Conium maculatum seed or plant during gestation days 43 through 53 and 51 through 61. The teratogenic effects in groups dosed during gestation days 43 through 53 were more severe than those in groups dosed during the later period, with many newborn pigs showing arthrogryposis and twisted and malaligned bones in the limbs and with 1 pig showing scoliosis and deformity of the thoracic cage. The pigs born to gilts given C maculatum during gestation days 51 through 61 had excessive flexure primarily in the carpal joints, without scoliosis or bone malalignment in the limbs. The teratogenicity of poison hemlock depends on the alkaloid concentration and content. Based on the data presented, we speculate that gamma-coniceine is the teratogenic alkaloid in the poison hemlock fed to the gilts. PMID:4062008

Panter, K E; Keeler, R F; Buck, W B

1985-10-01

187

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

NASA Astrophysics Data System (ADS)

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.

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

2010-03-01

188

Lupines, poison-hemlock and Nicotiana spp: toxicity and teratogenicity in livestock.  

PubMed

Many species of lupines contain quinolizidine or piperidine alkaloids known to be toxic or teratogenic to livestock. Poison-hemlock (Conium maculatum) and Nicotiana spp. including N. tabacum and N. glauca contain toxic and teratogenic piperidine alkaloids. The toxic and teratogenic effects from these plant species have distinct similarities including maternal muscular weakness and ataxia and fetal contracture-type skeletal defects and cleft palate. It is believed that the mechanism of action of the piperidine and quinolizidine alkaloid-induced teratogenesis is the same; however, there are some differences in incidence, susceptible gestational periods, and severity between livestock species. Wildlife species have also been poisoned after eating poison-hemlock but no terata have been reported. The most widespread problem for livestock producers in recent times has been lupine-induced "crooked calf disease." Crooked calf disease is characterized as skeletal contracture-type malformations and occasional cleft palate in calves after maternal ingestion of lupines containing the quinolizidine alkaloid anagyrine during gestation days 40-100. Similar malformations have been induced in cattle and goats with lupines containing the piperidine alkaloids ammodendrine, N-methyl ammodendrine, and N-acetyl hystrine and in cattle, sheep, goats, and pigs with poison-hemlock containing predominantly coniine or gamma-coniceine and N. glauca containing anabasine. Toxic and teratogenic effects have been linked to structural aspects of these alkaloids, and the mechanism of action is believed to be associated with an alkaloid-induced inhibition of fetal movement during specific gestational periods. This review presents a historical perspective, description and distribution of lupines, poison-hemlock and Nicotiana spp., toxic and teratogenic effects and management information to reduce losses. PMID:10091132

Panter, K E; James, L F; Gardner, D R

1999-02-01

189

Sex pheromone of the western hemlock looper, Lambdina fiscellaria lugubrosa (Hulst) (Lepidoptera: Geometridae)  

Microsoft Academic Search

The sex pheromone of the western hemlock looper (WHL),Lambdina fiscellaria lugubrosa (Hulst), comprises three methylated hydrocarbons: 5,11-dimethylheptadecane (5,11), 2,5-dimethylheptadecane (2,5), and 7-methylheptadecane (7). Compounds extracted from female pheromone glands were identified by coupled gas chromatographic-electroantennographic (GC-EAD) analysis and coupled GC-mass spectroscopy in selected ion monitoring mode. In trapping experiments, (5,11) alone attracted male moths, but addition of either (7) or

Gerhard Gries; Regine Gries; Shân H. Krannitz; Jianxiong Li; G. G. Skip King; Keith N. Slessor; John H. Borden; Wade W. Bowers; Rick J. West; Edward W. Underhill

1993-01-01

190

Sex pheromone components of the spring hemlock looper, Lambdina athasaria (Walker) (Lepidoptera: Geometridae)  

Microsoft Academic Search

Two methylated hydrocarbons, 7-methylheptadecane (7) and 7,11-dimethylheptadecane (7,11), are female sex pheromone components of the spring hemlock looper (SHL),Lambdina athasaria (Walker). Compounds extracted from female pheromone glands were identified by coupled gas chromatographic-electroantennographic detection (GC-EAD) and coupled GC-mass spectrometry (GC-MS) in selected ion monitoring mode. In field trapping experiments, (7) and (7,11) by themselves were behaviorally inactive, but in combination

Regine Gries; Gerhard Gries; Jianxiong Li; Chris T. Maier; Carol R. Lemmon; Keith N. Slessor

1994-01-01

191

Microbial communities and bacterial diversity of spruce, hemlock and grassland soils of Tatachia Forest, Taiwan  

Microsoft Academic Search

To evaluate the bacterial diversity of Tatachia Forest soils, 16S rDNA clone libraries of the spruce, hemlock and grassland soils were constructed. Further, the influence of physicochemical and biological properties of soil on microbial ecology, pH, moisture content, microbial population and biomass were also analyzed. The soil pH increased with the increasing of soil depth; whereas the microbial population, biomass,

Ammaiyappan Selvam; Shu-Hsien Tsai; Ching-Piao Liu; I-Chu Chen; Cheng-Hsiung Chang; Shang-Shyng Yang

2010-01-01

192

Sex pheromone components of the spring hemlock looper,Lambdina athasaria (Walker) (Lepidoptera: Geometridae).  

PubMed

Two methylated hydrocarbons, 7-methylheptadecane (7) and 7,11-dimethylheptadecane (7,11), are female sex pheromone components of the spring hemlock looper (SHL),Lambdina athasaria (Walker). Compounds extracted from female pheromone glands were identified by coupled gas chromatographic-electroantennographic detection (GC-EAD) and coupled GC-mass spectrometry (GC-MS) in selected ion monitoring mode. In field trapping experiments, (7) and (7,11) by themselves were behaviorally inactive, but in combination attracted numerous male moths. (5,11)-Dimethylheptadecane (5,11) was detected in female SHL pheromone gland extracts, but did not enhance attraction to the binary blend of (7) and (7,11). The sex pheromone of SHL is related to that of congeneric eastern hemlock looper (EHL),Lambdina fiscellaria fiscellaria (Guen.) [(5,11) and 2,5-dimethylheptadecane (2,5)] and western hemlock looper (WHL),L.f. lugubrosa (Hulst) [(5,11), (2,5) and (7)]. Specificity of the pheromonal blend, spatial separation of coseasonal EHL and WHL, and temporal separation of sympatric EHL and SHL contribute to reproductive isolation. PMID:24241827

Gries, R; Gries, G; Li, J; Maier, C T; Lemmon, C R; Slessor, K N

1994-10-01

193

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

PubMed Central

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

Jorgensen, Rachael; Arathi, H. S.

2013-01-01

194

Fungal pathogens of Euphorbia heterophylla and E. hirta in Brazil and their potential as weed biocontrol agents.  

PubMed

A two-year survey of the fungi associated with two important congeneric pantropical weeds, Euphorbia heterophylla and E. hirta, was conducted in part of their native range in southern Brazil. Sampling was concentrated mainly in Rio de Janeiro State and ten species were identified as pathogens of these weeds. Two taxa, Botrytis ricini and Uromyces euphorbiae, were common to both weed hosts. Alternaria euphorbiicola, Bipolaris euphorbiae, Melampsora sp., Oidium sp. and Sphaceloma poinsettiae were recorded only from E. heterophylla, whereas Colletotrichum gloeosporioides, Sphaceloma sp. and Sphaerotheca fuliginea were restricted to E. hirta. Botrytis ricini and Colletotrichum gloeosporioides are new records for E. hirta, and Alternaria euphorbiicola and Sphaerotheca fuliginea are new host records for Brazil. Bipolaris euphorbiae, previously identified as Helminthosporium sp., is considered to be the correct name for the causal agent of a major disease of E. heterophyllum in Brazil. The potential of these pathogens as biocontrol agents is discussed and the mycobiota associated with both these weeds worldwide is reviewed. PMID:16284862

Barreto, R W; Evans, H C

1998-01-01

195

Radio ultrasound observations of the fetotoxic effects in sheep from ingestion of Conium maculatum (poison-hemlock).  

PubMed

Fetal movement in pregnant ewes gavaged with Conium maculatum (poison-hemlock) was reduced significantly, but temporarily. Fetal movement was observed by radio ultrasound at 45, 54 and 60 days of gestation in control ewes and on days 45, 54, and 60 of gestation immediately before and 1 hour following poison-hemlock feeding in treated ewes. Fetal movement was significantly reduced (P less than 0.01) 1 hour after poison-hemlock administration, but returned to normal within 18 hours post treatment. At parturition seven of eleven lambs born to seven treated ewes had varying degrees of front limb abnormalities. Modest to moderate flexure of the carpal joints, some lateral deviation in the front limbs at the pastern joint and kinked tails were observed. These malformations were transient and resolved spontaneously by 8 weeks after lambing. PMID:3047418

Panter, K E; Bunch, T D; Keeler, R F; Sisson, D V

1988-01-01

196

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

PubMed

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

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

2015-02-01

197

Hemlock Alkaloids in Aloes. Occurrence and Distribution of gamma-Coniceine.  

PubMed

The hemlock alkaloid gamma-coniceine was identified in a number of ALOE species, namely A. GILLILANDII, Reynolds A. BALLYI Reynolds, A. RUSPOLIANA Baker, A. IBITIENSIS Perrier and A. DELTOIDEODONTA Baker. Coniine was identified in A. VIGUIERI Perrier. The levels of gamma-coniceine are higher than those found in CONIUM MACULATUM L. Some species also contained trace amounts of conhydrinone and pseudoconhydrin. Three of the species are Madagascan endemics, one is restricted to Arabia, while the rest are remote from each other in East Africa. Some of the species are loosely related but there is no overall taxonomic affinity between them. PMID:17340347

Dring, J V; Nash, R J; Roberts, M F; Reynolds, T

1984-10-01

198

Maternal and fetal toxicity of poison hemlock (Conium maculatum) in sheep.  

PubMed

Poison hemlock (Conium maculatum) was toxic to pregnant ewes and their fetuses when fed during gestation days 30 through 60. Maternal effects included trembling, muscular weakness in the neck initially, then progressing to the limbs, ataxia, frequent urination and defecation, and death. Convulsive seizures were not observed. Fetotoxic effects included excessive flexure of the carpal joints with lateral deviation in the front limbs and kinked tails. At term, 7 of 11 lambs had varying degrees of the limb abnormalities, but all lambs appeared clinically normal at 8 weeks after parturition. PMID:3348538

Panter, K E; Bunch, T D; Keeler, R F

1988-02-01

199

Forested Communities of the Upper Montane in the Central and Southern  

E-print Network

), lodgepole pine (Pinus contorta), mountain hemlock (Tsuga mertensiana), western white pine (Pinus monticola magnifica), white fir (Abies concolor), sugar pine (Pinus lambertiana), Jeffrey pine (Pinus Jeffreyii

Standiford, Richard B.

200

122 2010 USDA Research Forum on Invasive Species GTR-NRS-P-75 COMPARISON OF FECUNDITY AND SURVIVAL  

E-print Network

OF HEMLOCK WOOLLY ADELGID (HEMIPTERA: ADELGIDAE) IN NORTHERN AND SOUTHERN POPULATIONS Artemis Roehrig), Adelges tsugae Annand (Hemiptera: Adelgidae), is an introduced species first reported in the eastern

201

78 FR 14509 - Availability of an Environmental Assessment and Finding of No Significant Impact for a Biological...  

Federal Register 2010, 2011, 2012, 2013, 2014

...hemlock woolly adelgid is a destructive pest of the eastern hemlock (Tsuga canadensis), where it causes needle loss, abortion of buds, and the eventual death of infested trees. On August 3, 2012, we published in the Federal Register (77 FR...

2013-03-06

202

Ecosystem function in Appalachian headwater streams during an active invasion by the hemlock woolly adelgid.  

PubMed

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

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

2013-01-01

203

Sex pheromone of the western hemlock looper,Lambdina fiscellaria lugubrosa (Hulst) (Lepidoptera: Geometridae).  

PubMed

The sex pheromone of the western hemlock looper (WHL),Lambdina fiscellaria lugubrosa (Hulst), comprises three methylated hydrocarbons: 5,11-dimethylheptadecane (5,11), 2,5-dimethylheptadecane (2,5), and 7-methylheptadecane (7). Compounds extracted from female pheromone glands were identified by coupled gas chromatographic-electroantennographic (GC-EAD) analysis and coupled GC-mass spectroscopy in selected ion monitoring mode. In trapping experiments, (5,11) alone attracted male moths, but addition of either (7) or (2,5) significantly enhanced attraction. (5,11) combined with both (7) and (2,5) was significantly most attractive. (5,11) and (2,5) are also sex pheromone components of the eastern hemlock looper (EHL),Lambdina fiscellaria fiscellaria (Guen.). Although (7) is produced by the EHL, it is a pheromone component only in the WHL. It constitutes the first behaviorally active monomethyl-branched hydrocarbon to be found in a geometrid and is a novel lepidopteran sex pheromone component. The different 2- versus 3-component sex pheromone supports taxonomic division of EHL and WHL. PMID:24249080

Gries, G; Gries, R; Krannitz, S H; Li, J; King, G G; Slessor, K N; Borden, J H; Bowers, W W; West, R J; Underhill, E W

1993-05-01

204

Developmental polymorphism in a Newfoundland population of the hemlock looper, Lambdina fiscellaria (Lepidoptera: Geometridae).  

PubMed

The hemlock looper [Lambdina fiscellaria (Guenée)], a widespread and highly polyphagous Geometridae, is considered one of the most economically important defoliators of North American coniferous forests. Variations in the number of larval instars between geographic populations of this species have been previously reported in the literature. However, whether such developmental polymorphism occurs within a given population is unknown. In this study, we report the presence of both four and five larval instar individuals within a population of hemlock looper in Newfoundland when reared on balsam fir. For both sexes, the majority of individuals reared on balsam fir shoots went through four larval instars, but more than one third of the females (35.3%) went through five larval instars. Females with four larval instars developed faster and had smaller pupal weight than females with five larval instars. However, a growth-related index (weight gain per unit of time) was similar for the two ecotypes (four or five larval instars). No significant difference was observed between the two ecotypes in terms of reproductive capacity (fecundity and egg size). We also found significant differences in life history traits between males and females. Results indicate that developmental polymorphism, in this case, the variation in the number of larval instars, might provide some adaptive attributes that allowed exploitation of a broader ecological niche. PMID:17716462

Berthiaume, Richard; Bauce, Eric; Hébert, Christian; Brodeur, Jacques

2007-08-01

205

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...

206

Impacts of hemlock looper defoliation on growth and survival of balsam fir, black spruce and white birch in Newfoundland, Canada  

Microsoft Academic Search

Hemlock looper (Lambdina fiscellaria fiscellaria (Guen.)) is an economically damaging defoliator that undergoes periodic outbreaks in Newfoundland, Canada. It defoliates and causes extensive tree mortality to its primary host, balsam fir (Abies balsamea [L.] Mill.). We quantified tree survival using data from permanent sample plots (PSPs) and growth reduction or release using dendrochronology, and related these impacts to defoliation severity

Javed Iqbal; David A. MacLean; John A. Kershaw

2011-01-01

207

Density-dependent and density-independent responses of three species of Telenomus parasitoids of hemlock looper eggs  

Microsoft Academic Search

We examined patterns of host exploitation by natural populations of three Telenomus species (Hymenoptera: Scelionidae) parasitizing hemlock looper, Lambdina fiscellaria Guenee (Lepidoptera: Geometridae), eggs in sentinel traps in eastern Quebec and western Newfoundland (Canada). The percentage of eggs parasitized by Telenomus flavotibiae Pelletier and Telenomus coloradensis Crawford in autumn, and by Telenomus droozi Muesebeck in spring either were not or

Drew Carleton; Dan Quiring; Steve Heard; Christian Hebert; Johanne Delisle; Richard Berthiaume; Eric Bauce; Lucie Royer

2010-01-01

208

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

PubMed

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

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

2012-12-01

209

Abietoid seed fatty acid composition—A review of the genera Abies, Cedrus, Hesperopeuce, Keteleeria, Pseudolarix , and Tsuga and preliminary inferences on the taxonomy of Pinaceae  

Microsoft Academic Search

The seed fatty acid (FA) compositions of Abietoids (Abies, Cedrus, Hesperopeuce, Keteleeria, Pseudolarix, and Tsuga) are reviewed in the present study in conclusion to our survey of Pinaceae seed FA compositions. Many unpublished data are\\u000a given. Abietoids and Pinoids (Pinus, Larix, Ficea, and Pseudotsuga)—constituting the family Pinaceae—are united by the presence of several ?5-olefinic acids, taxoleic (5,9–18?2), pinolenic\\u000a (5,9,12–18?3) coniferonic

Robert L. Wolff; Olivier Lavialle; Frédérique Pédrono; Elodie Pasquier; Frédéric Destaillats; Anne M. Marpeau; Paul Angers; Kurt Aitzetmüller

2002-01-01

210

Evaluation of volatiles from Ampelopsis brevipedunculata var. heterophylla using GC-olfactometry, GC-MS and GC-pulsed flame photometric detector.  

PubMed

Ampelopsis brevipedunculata var. heterophylla is extensively cultivated in Asia, and the dried leaves and branches have a characteristic odor and have been used as a tea. To investigate the odorants contributing to the characteristic odor of A. brevipedunculata var. heterophylla, the aroma extraction dilution analysis method was performed through gas chromatography olfactometry. In addition, volatile sulfur compounds were evaluated using pulsed flame photometric detector. As a result, 86 compounds were identified in the oils of leaves and 78 in branches, accounting for 80.0% and 68.3%, respectively, of the compounds identified. The main compounds in the essential oil of leaves were palmitic acid (12.5%), phenylacetaldehyde (4.1%) and hexahydrofarnesyl acetone (3.9%). On the other hand, the essential oil of branches contained palmitic acid (12.7%), terpinen-4-ol (4.4%) and ?-cadinol (3.7%). The total number of odor-active compounds identified in the leaf and branch oils was 39. The most odorous compounds of leaves and branches of A. brevipedunculata var. heterophylla were (E, Z)-2,6-nonadienal (melon, green odor), (E)-2-nonenal (grassy odor), phenylacetaldehyde (honey-like) and (E)-linalool oxide (woody odor). PMID:24005009

Nakamura, Atsuhiko; Miyazawa, Mitsuo

2013-01-01

211

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

NASA Technical Reports Server (NTRS)

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.

Cohen, Warren B.; Spies, Thomas A.

1992-01-01

212

Comparative toxicity of coniine, an alkaloid of Conium maculatum (poison hemlock), in chickens, quails, and turkeys.  

PubMed

Coniine, an alkaloid of Conium maculatum (poison hemlock), was administered by gavage to immature chickens, quails, and turkeys at 0, 25, 50, and 100 mg/kg body weight. At 25 mg coniine/kg body weight, clinical signs were observed only in quails (2/10) and consisted of excitement, depression, hypermetria, seizures, opisthotonos, and flaccid paralysis. Chickens (9/10) and quails (8/10) dosed at 50 mg/kg body weight were affected, and several birds of each species died (2/10 and 5/10, respectively). Turkeys (7/10) were affected only when dosed at 100 mg/kg body weight, and quails (6/10), turkeys (4/10), and chickens (10/10) died at this dose. There were no gross or microscopic lesions. Coniine was detected in skeletal muscle and liver of birds dying after ingestion and was present in some survivors 7 days post-treatment. PMID:2369382

Frank, A A; Reed, W M

1990-01-01

213

Who is fighting for the right to die? Older women's participation in the Hemlock Society.  

PubMed

Who is fighting for the right to die? Past literature has been mixed as to the membership of this social movement. In the current study, 6,398 Hemlock Society members were surveyed in an effort to answer questions concerning who is participating in the right to die movement, whether these participants are rapidly approaching their own death or reacting to the death of a loved one, and whether the movement is invigorated by singular activists. The findings indicate that older, white, wealthy, highly educated, economically and politically active women are in the forefront of the right to die movement. These women report currently being mentally and physically healthy, yet already having taken the steps that will allow them to have an element of control over their death. Finally, right to die support seems to be part of a larger collective network concerning health care and political policy issues. PMID:9849186

Wilson, J K; Fox, E; Kamakahi, J J

1998-01-01

214

OCCURRENCE AND REPRODUCTIVE ROLE OF REMNANT OLD-GROWTH TREES IN MATURE DOUGLAS-FIR FORESTS,  

E-print Network

the re-establishment of shade-tolerant conifers (Tsuga heterophylla and Thuja plicata) by increasing, including sites with and without remnant Thuja and Tsuga. Overstory structure and composition, microsite. Live remnant Tsuga and Thuja trees were strongly associated with convergent landforms that had greater

Keeton, William S.

215

Chirality of 5,11-dimethylheptadecane, the major sex pheromone component of the hemlock looper,Lambdina fiscellaria (Lepidoptera: Geometridae).  

PubMed

Of the four possible stereoisomers of 5,11-dimethylheptadecane, the major sex pheromone component of the eastern hemlock looper (EHL),Lambdina fiscellaria fiscellaria Guen., and the western hemlock looper (WHL),Lambdina fiscellaria lugubrosa Hulst, (5R,11S)-5,11-dimethylheptadecane was the only stereoisomer eliciting electrophysiological responses by male EHL and WHL antennae. In field bioassays with EHL and WHL populations, traps baited with (5R,11S)-5, 11-dimethylheptadecane caught as many males as did traps baited with all four stereoisomers combined or a synthetic mixture of 5,11-dimethylheptadecanes. Catches in traps baited with the other three stereoisomers did not significantly differ from those in the unbaited control traps. We conclude that male antennae lack chemoreceptors for the other three stereoisomers of 5,11-dimethylheptadecane and hypothesize that only (5R,115)-5,11-dimethylheptadecane is produced by female EHLs and WHLs. PMID:24249125

Jianxiong, L; Gries, R; Gries, G; Slessor, K N; King, G G; Bowers, W W; West, R J

1993-06-01

216

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

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

217

Transcriptionally mediated inhibition of telomerase of fungal immunomodulatory protein from Ganoderma tsugae in A549 human lung adenocarcinoma cell line.  

PubMed

Telomerase expression is the hallmark of tumor cells, and activation of this ribonucleoprotein complex may be a rate-limiting or critical step in cellular immortalization and oncogenesis. Fungal immunomodulatory protein, FIP-gts, has been isolated from Ganoderma tsugae. In the present study, we expressed and purified the recombinant fungal immunomodulatory protein reFIP-gts in E. coli. We found that reFIP-gts significantly and selectively inhibits the growth of A549 cancer cells while not affecting the growth of normal MRC-5 fibroblasts. The reFIP-gts suppression of telomerase activity is concentration-dependent, due to the downregulation of the telomerase catalytic subunit (hTERT). It also happens at the mRNA level. These results were confirmed by transient transfections of A549 cells with pGL3-Basic plasmid constructs containing the functional hTERT promoter and its E-box-deleted sequences cloned upstream of a luciferase reporter gene. With electrophoretic mobility shift assays and Western blotting, we demonstrated that in response to reFIP-gts, binding of c-myc transcriptional factor to the E-box sequence on the hTERT promoter is inhibited. These results show that reFIP-gts suppresses telomerase activity and inhibits transcriptional regulation of hTERT via a c-myc-responsive element-dependent mechanism. Our findings provide new insight into both the anticancer function of reFIP-gts and the regulation of hTERT/telomerase expression, which may be valuable in the development of a promising chemopreventive agent. PMID:16402390

Liao, Chien-Huang; Hsiao, Yi-Min; Hsu, Chung-Ping; Lin, Meei-Yn; Wang, James Chun-Huan; Huang, Yu-Lu; Ko, Jiunn-Liang

2006-04-01

218

Abietoid seed fatty acid compositions--a review of the genera Abies, Cedrus, Hesperopeuce, Keteleeria, Pseudolarix, and Tsuga and preliminary inferences on the taxonomy of Pinaceae.  

PubMed

The seed fatty acid (FA) compositions of Abietoids (Abies, Cedrus, Hesperopeuce, Keteleeria, Pseudolarix, and Tsuga) are reviewed in the present study in conclusion to our survey of Pinaceae seed FA compositions. Many unpublished data are given. Abietoids and Pinoids (Pinus, Larix, Picea, and Pseudotsuga)-constituting the family Pinaceae-are united by the presence of several delta5-olefinic acids, taxoleic (5,9-18:2), pinolenic (5,9,12-18:3), coniferonic (5,9,12,15-1 8:4), keteleeronic (5,11-20:2), and sciadonic (5,11,14-20:3) acids, and of 14-methyl hexadecanoic (anteiso-17:0) acid. These acids seldom occur in angiosperm seeds. The proportions of individual delta5-olefinic acids, however, differ between Pinoids and Abietoids. In the first group, pinolenic acid is much greater than taxoleic acid, whereas in the second group, pinolenic acid is greater than or equal to taxoleic acid. Moreover, taxoleic acid in Abietoids is much greater than taxoleic acid in Pinoids, an apparent limit between the two subfamilies being about 4.5% of that acid relative to total FA. Tsuga spp. appear to be a major exception, as their seed FA compositions are much like those of species from the Pinoid group. In this respect, Hesperopeuce mertensiana, also known as Tsuga mertensiana, has little in common with Abietoids and fits the general FA pattern of Pinoids well. Tsuga spp. and H. mertensiana, from their seed FA compositions, should perhaps be separated from the Abietoid group and their taxonomic position revised. It is suggested that a "Tsugoid" subfamily be created, with seed FA in compliance with the Pinoid pattern and other botanical and immunological criteria of the Abietoid type. All Pinaceae genera, with the exception of Pinus, are quite homogeneous when considering their overall seed FA compositions, including delta5-olefinic acids. In all cases but one (Pinus), variations from one species to another inside a given genus are of small amplitude. Pinus spp., on the other hand, have highly variable levels of delta5-olefinic acids in their FA compositions, particularly when sections (e.g., Cembroides vs. Pinus sections) or subsections (e.g., Flexiles and Cembrae subsections from the section Strobus) are compared, although they show qualitatively the same FA patterns characteristic of Pinoids. Multicomponent analysis of Abietoid seed FA allowed grouping of individual species into genera that coincide with the same genera otherwise characterized by more classical botanical criteria. Our studies exemplify how seed FA compositions, particularly owing to the presence of delta5-olefinic acids, may be useful in sustaining and adding some precision to existing taxonomy of the major family of gymnosperms, Pinaceae. PMID:11876259

Wolff, Robert L; Lavialle, Olivier; Pédrono, Frédérique; Pasquier, Elodie; Destaillats, Frederic; Marpeau, Anne M; Angers, Paul; Aitzetmüller, Kurt

2002-01-01

219

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

USGS Publications Warehouse

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.

Cross, Alison; Perakis, Steven S.

2011-01-01

220

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

PubMed Central

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

2013-01-01

221

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)

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.

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

2002-05-01

222

Chirality of synergistic sex pheromone components of the western hemlock looper Lambdina fiscellaria lugubrosa (HULST) (Lepidoptera: Geometridae)  

Microsoft Academic Search

Bakers' yeast reduction of (2E)-3-(2'-furanyl)-2-methyl-2-propenal yielded the synthetic intermediate, (2S)-3-(2'-furanyl)-2-methylpropanol, of high chiral purity (>97% ee) for the synthesis of the enantiomers of 2,5-dimethylheptadecane and 7-methylheptadecane, two synergistic sex pheromone components of the western hemlock looper (WHL),Lambdina fiscellaria lugubrosa Hulst. In electrophysiological bioassays, (7S)- but not (7R)-7-methylheptadecane elicited strong antennal responses by male WHL antennae. In field trapping experiments, addition

Jianxiong Li; Gerhard Gries; Regine Gries; Jovo Bikic; Keith N. Slessor

1993-01-01

223

Pesticide residues in Hemlock and Canadice Lakes and their tributaries in western New York, 1997-98  

USGS Publications Warehouse

In 1997, the U.S.Geological Survey (USGS) and the City of Rochester began a cooperative program to study the presence of pesticides (herbicides and insecticides) that occur at trace levels in Hemlock and Canadice Lakes and their tributaries. The most frequently detected pesticides in streamflow and lake-water samples were herbicides commonly used in agriculture ? atrazine, metolachlor, and simazine. None of the concentrations of these compounds in the samples exceeded Federal or State water-quality standards. Differences in the concentrations among stream samples can be attributed to land use and streamflow, and the timing of rainfall in relation to herbicide application. The north (lower) end of Hemlock Lake can receive pesticides in agricultural runoff from northern parts of its watershed and Canadice Creek. These pesticide inputs bypass most of the lake and could periodically affect the water quality periodically affect the water quality at the City of Rochester intake. Pesticide concentrations in samples from the intake during this study, however, were about 100 times less than current Federal and State standards for drinking water. Residues of DDT, dieldrin, and mirex are present in low concentrations in the bottom sediments of both lakes, but none were detected in water samples. The use of these insecticides was banned in 1972,and their persistence in the lakebed sediments is probably due to erosion of contaminated soils from agricultural lands.

Eckhardt, David A.; Burke, Sarah

2000-01-01

224

Estimating cumulative defoliation of balsam fir from hemlock looper and balsam fir sawfly using aerial defoliation survey in western Newfoundland, Canada  

Microsoft Academic Search

Both hemlock looper (Lambdina fiscellaria fiscellaria (Guen.)) and balsam fir sawfly (Neodiprion abietis (Harris)) undergo periodic outbreaks in eastern Canada and cause significant growth and mortality losses to forests. Tree growth and mortality are closely related to cumulative defoliation estimates, which integrate annual defoliation over multiple years. Our objective was to determine a method to estimate cumulative defoliation of balsam

Javed Iqbal; David A. MacLean

2010-01-01

225

Upper petal lip colour polymorphism in Collinsia heterophylla (Plantaginaceae): genetic basis within a population and its use as a genetic marker.  

PubMed

Understanding the genetics of a polymorphic trait is important to predict its likely evolution. In Collinsia heterophylla, the upper petal lip colour can be either be white or white with a purple band, while the lower petal lip colour is invariably purple. Because the corolla is only partly polymorphic, the polymorphism can not have evolved due to a mutation where a pigment was lost in the entire plant, which is common in other polymorphic species. In a previous study, high frequency of the purple band was found in populations with darker flowers, indicating possible selection for this trait. In this study, I determined inheritance of the colour polymorphism using two populations (one with only white morph and other with both morphs). I conducted experimental crosses within and between floral morphs to determine whether patterns of segregation in offspring conform to single-gene predictions. Data from F1, F2, F3 and backcross progeny are consistent with a genetic model of one major locus with presence of the band being completely dominant, as indicated in earlier studies using distantly related populations. A novel finding in this study was that the two morphs did not show a difference in seed germination frequency or seedling survival. This trait can thus be valuable as a genetic marker. Even though more thorough ecological data are needed to understand the potential selection pressures on upper petal lip colour in C. heterophylla, its simple inheritance may indicate the possibility of fast evolutionary response to selective forces acting on this trait. PMID:19700859

Lankinen, Asa

2009-08-01

226

Armored scale insect endosymbiont diversity at the species level: genealogical patterns of Uzinura diasipipdicola in the Chionaspis pinifoliae-Chionaspis heterophyllae species complex (Hemiptera: Coccoidea: Diaspididae).  

PubMed

Armored scale insects and their primary bacterial endosymbionts show nearly identical patterns of co-diversification when viewed at the family level, though the persistence of these patterns at the species level has not been explored in this group. Therefore we investigated genealogical patterns of co-diversification near the species level between the primary endosymbiont Uzinura diaspidicola and its hosts in the Chionaspis pinifoliae-Chionaspis heterophyllae species complex. To do this we generated DNA sequence data from three endosymbiont loci (rspB, GroEL, and 16S) and analyzed each locus independently using statistical parsimony network analyses and as a concatenated dataset using Bayesian phylogenetic reconstructions. We found that for two endosymbiont loci, 16S and GroEL, sequences from U. diaspidicola were broadly associated with host species designations, while for rspB this pattern was less clear as C. heterophyllae (species S1) shared haplotypes with several other Chionaspis species. We then compared the topological congruence of the phylogenetic reconstructions generated from a concatenated dataset of endosymbiont loci (including all three loci, above) to that from a concatenated dataset of armored scale hosts, using published data from two nuclear loci (28S and EF1?) and one mitochondrial locus (COI-COII) from the armored scale hosts. We calculated whether the two topologies were congruent using the Shimodaira-Hasegawa test. We found no significant differences (P = 0.4892) between the topologies suggesting that, at least at this level of resolution, co-diversification of U. diaspidicola with its armored scale hosts also occurs near the species level. This is the first such study of co-speciation at the species level between U. diaspidicola and a group of armored scale insects. PMID:25424737

Andersen, J C; Gwiazdowski, R A; Gdanetz, K; Gruwell, M E

2015-02-01

227

50 CFR 17.95 - Critical habitat-fish and wildlife.  

Code of Federal Regulations, 2013 CFR

...Tsuga heterophylla )/western red cedar (Thuja plicata ) climax forest... ER15DE10.005 (9) Unit 4: Cedar Creek, Larimer County, Colorado...5 mi (12.1 km) of streams. Cedar Creek from the boundary of...

2013-10-01

228

Thuja plicata exclusion in ectomycorrhiza-dominated forests: testing the role of inoculum potential of arbuscular mycorrhizal fungi.  

PubMed

The ability of trees dependent on arbuscular mycorrhizal (AM) fungi to establish in ectomycorrhizal forests is unknown. On northern Vancouver Island, Canada, there are sharp boundaries between mixed red cedar (Thuja plicata)-hemlock (Tsuga heterophylla) (CH) stands, and stands of hemlock and amabilis fir (Abies amabilis) (HA). We tested differences in AM colonization of red cedar between ectomycorrhiza-dominated (HA) stands and stands containing red cedar (CH), across a range of light levels. We used a soil bioassay approach to determine whether there was sufficient AM fungal inoculum in the HA tree stands to colonize red cedar seedlings. Seeds of hemlock and red cedar were sown in forest floor samples collected from the two types of forests, and shade treatments ranging from < 1 to 53% of full sunlight were imposed. After 6 months, seedling survival and root and shoot biomass were quantified, and red cedar seedlings were sampled for AM fungal colonization. Hemlock survival and growth did not differ between soil types, suggesting there was no substrate-associated limitation to its establishment in either forest type. Red cedar colonization by AM fungi was significantly correlated with light levels in CH soils but arbuscular mycorrhizas were absent in roots of red cedar seedlings grown in HA soil. Red cedar survival and relative growth rate were significantly greater in the CH than in HA soil; higher growth was due primarily to greater shoot growth in CH soils at high light levels. The low soil inoculum potential for red cedar in ectomycorrhiza-dominated stands may account for the virtual exclusion of red cedar seedlings from these forests. PMID:15583941

Weber, Adrian; Karst, Justine; Gilbert, Benjamin; Kimmins, J P

2005-03-01

229

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

PubMed

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 (?(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 ?(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 ?(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

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

2014-07-01

230

Factors influencing fungal degradation of lignin in a representative lignocellulosic, thermomechanical pulp  

SciTech Connect

This research examined culture parameters influencing the rate of degradation of lignin in lignocellulosic substrates by the Basidiomycete Phanerochaete chryosoprorium. Thermomechanical pulps prepared from western hemlock (Tsuga heterophylla) and red alder (Alnus rubra) were chosen as model substrates. Degradation of lignin in shallow, liquid-phase, stationary cultures was 10 times as rapid as in agitated cultures. Lignin degradation was at least 50% more rapid in cultures under 100% O/sub 2/ than in those under air. Addition of 0.12% nutrient N (dry pulp basis ) increased the rate of lignin degradation two- to fivefold; 1.2% added N at first suppressed, then stimulated, lignin degradation. Lignin in the alder pulp was degraded over five times as rapidly as in the hemlock pulp. Addition of glucose (35% of dry pulp) to the pulps containing 0.12% added N completely suppressed polysaccharide depletion during two weeks, but did not infleunce lignin degradation. The maximum rate of lignin degradation was 3%/day over a two-week incubation, or approximately 2.9 mg/mg fungal cell protein/day. The influence of the examined parameters was in complete accord with those found earlier for synthetic /sup 14/C-lignin metabolism by P. chrysosporium.

Yang, H.H.; Effland, M.J.; Kirk, T.K.

1980-01-01

231

Retention of canopy lichens after partial-cut harvesting in wet-belt interior cedar–hemlock forests, British Columbia, Canada  

Microsoft Academic Search

Old-growth cedar–hemlock forests of the interior wet-belt of British Columbia are rich in abundance and diversity of canopy lichens, but are subject to forest harvesting. If these distinctive canopy lichen communities are to be conserved, it is important to learn how they are affected by forestry practices, including partial-cutting techniques designed to retain old-growth attributes. The retention of canopy lichens

Darwyn S. Coxson; Susan K. Stevenson

2005-01-01

232

Effects of Relative Humidity and Temperature on Entomophaga aulicae Conidium Discharge from Infected Eastern Hemlock Looper Larvae and Subsequent Conidium Development  

Microsoft Academic Search

The effects of relative humidity (RH) and temperature on conidium discharge from Entomophaga aulicae-infected eastern hemlock looper (Lambdina fiscellaria fiscellaria) larvae and subsequent conidium development were examined. Fourth-instar larvae were injected with 460 fungal protoplasts (=LC50 dosage). At 20°C, RH (66, 86, and 93%) had no effect on the level of larval mortality. At 93% RH, more primary, secondary, tertiary,

Dawn M. McDonald; Richard A. Nolan

1995-01-01

233

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

PubMed Central

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

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

234

Vesicular endophytes in roots of the Pinaceae  

Microsoft Academic Search

Vesicles and hyphae typical of vesicular-arbuscular mycorrhizae (VAM) were common in seedlings of Pseudotsuga menziesii, Abies lasiocarpa and Tsuga mertensiana growing in openings where herbaceous hosts of these fungi were common. Seedlings of A. lasiocarpa, Tsuga heterophylla, and T. mertensiana growing under closed forest canopies also had vesicles but at a much lower incidence than seedlings in the openings. The

E. Cázares; J. M. Trappe

1993-01-01

235

Riparian forest composition affects stream litter decomposition despite similar microbial and invertebrate communities.  

PubMed

Cross-boundary flows of energy and nutrients link biodiversity and functioning in adjacent ecosystems. The composition of forest tree species can affect the structure and functioning of stream ecosystems due to physical and chemical attributes, as well as changes in terrestrial resource subsidies. We examined how variation in riparian canopy composition (coniferous, deciduous, mixed) affects adjacent trophic levels (invertebrate and microbial consumers) and decomposition of organic matter in small, coastal rainforest streams in southwestern British Columbia. Breakdown rates of higher-quality red alder (Alnus rubra) litter were faster in streams with a greater percentage of deciduous than coniferous riparian canopy, whereas breakdown rates of lower-quality western hemlock (Tsuga heterophylla) litter were independent of riparian forest composition. When invertebrates were excluded using fine mesh, breakdown rates of both litter species were an order of magnitude less and were not significantly affected by riparian forest composition. Stream invertebrate and microbial communities were similar among riparian forest composition, with most variation attributed to leaf litter species. Invertebrate taxa richness and shredder biomass were higher in A. rubra litter; however, taxa evenness was greatest for T. heterophylla litter and both litter species in coniferous streams. Microbial community diversity (determined from terminal restriction fragment length polymorphisms) was unaffected by riparian forest or litter species. Fungal allele richness was higher than bacterial allele richness, and microbial communities associated with lower-quality T. heterophylla litter had higher diversity (allele uniqueness and richness) than those associated with higher-quality A. rubra litter. Percent variation in breakdown rates was mostly attributed to riparian forest composition in the presence of invertebrates and microbes; however, stream consumer biodiversity at adjacent trophic levels did not explain these patterns. Riparian and stream ecosystems and their biotic communities are linked through exchange and decomposition of detrital resources, and we provide evidence that riparian forest composition affects stream ecosystem catabolism despite similarities in microbial and invertebrate communities. PMID:21560685

Kominoski, John S; Marczak, Laurie B; Richardson, John S

2011-01-01

236

Chirality of synergistic sex pheromone components of the western hemlock looperLambdina fiscellaria lugubrosa (HULST) (Lepidoptera: Geometridae).  

PubMed

Bakers' yeast reduction of (2E)-3-(2'-furanyl)-2-methyl-2-propenal yielded the synthetic intermediate, (2S)-3-(2'-furanyl)-2-methylpropanol, of high chiral purity (>97% ee) for the synthesis of the enantiomers of 2,5-dimethylheptadecane and 7-methylheptadecane, two synergistic sex pheromone components of the western hemlock looper (WHL),Lambdina fiscellaria lugubrosa Hulst. In electrophysiological bioassays, (7S)- but not (7R)-7-methylheptadecane elicited strong antennal responses by male WHL antennae. In field trapping experiments, addition of (7S)- but not (7R)-7-methylheptadecane to (5R,11S)-5,11-dimethylheptadecane, the major sex pheromone component of WHL, increased attraction. Attraction to (5R,11S)-5,11-dimethylheptadecane in combination with (7S)-7-methyiheptadecane was further enhanced by the addition of (5S)- but not (5R)-2,5-dimethylheptadecane. Similarly, attraction to (5R,11S)-5,11-dimethylheptadecane combined with (5S)-2,5-dimethylheptadecane increased when 7S- but not (7R)-7-methylheptadecane was added as a third component. We conclude that (7S)-7-methylheptadecane and (5S)-2,5-dimethylheptadecane are the synergistic sex pheromone components of WHL. The synthetic methodology described is applicable to the synthesis of chiral methyl-branched pheromones in other orders of the Insecta, particularly Coleoptera, Diptera and Orthoptera. PMID:24248710

Li, J; Gries, G; Gries, R; Bikic, J; Slessor, K N

1993-11-01

237

Distribution of 15N Tracers Applied to the Canopy of a Mature Spruce-Hemlock Stand: Implications for Carbon Sequestration  

NASA Astrophysics Data System (ADS)

Fertilization, through increases in N deposition, can enhance plant growth and thus impact other elemental cycles including that of carbon. However, in many N fertilization experiments chemical amendments are added to soils, making soils and not plants the short term recipient of additional N (years to decades). In 2001, a dissolved fertilizer addition of 18 kg N/ha to a 21 ha plot in a Maine spruce-hemlock forest was initiated to investigate the importance of canopy N processes and impacts on C sequestration. In smaller subplots (0.3 ha), additional N inputs were made with tracer levels of enriched N, as either 15NH4+ or 15NO3-. Ecosystem pools, canopy gaseous N losses, and dissolved N fluxes in the 15N subplots were analyzed to determine ecosystem N retention and estimate the impact on C sequestration. Ecosystem retention of 15NH4+ and 15NO3- was 38% and 70% respectively, much of this (~75%) was recovered in the canopy, yet little N (<5%) was recovered in woody matter with a high C:N ratio. Despite a large canopy N retention potential in this forest, C sequestration into new wood growth was ~4-5 g C m-2 y-1 or about 2% above the current net annual C sequestration for this site after 3 years of fertilization.

Davidson, E.; Dail, D. B.; Hollinger, D. Y.; Davidson, E.; Sievering, H.; Scott, N.; Fernandez, I.; Aber, J.; Gaige, E.

2007-12-01

238

Quaternary Science Reviews 21 (2002) 17931805 Parallel climate and vegetation responses to the early Holocene  

E-print Network

-levels and expanded populations of moist-tolerant southern pines (Pinus) document that summer monsoons intensified, such as beech (Fagus) and hemlock (Tsuga), replaced those of dry-tolerant northern pines (Pinus). Available

2002-01-01

239

Trophic cascades, invasive species and body-size hierarchies interactively  

E-print Network

) and hemlock (Tsuga canadensis), while boreal forests are dominated by white spruce (Picea glauca), black spruce (Picea mariana), red spruce (Picea rubens), balsam fir (Abies balsamea), paper birch (Betula

240

Is Conservation Conservative? How Ideology Influences Natural Resource  

E-print Network

?.......................................................8 Representations of Natural Gas Development Via Hydraulic Fracturing ...................................................11 Management Strategies for the Hemlock Woolly Adelgid, Adelges tsugae Annand, in New York........11 Hydrologic Impact of Roadside Ditches in an Agricultural Watershed in Central New York: Implications for Non

Walter, M.Todd

241

Establishment Report (1st Approximation) Northern Wetbelt Silvicultural Systems Project  

E-print Network

of this site series. (Mean cover 37%) A1- western redcedar Thuja plicata (25%) (western hemlock Tsuga ­ devil's club Oplopanax horridus (5%) (Douglas maple Acer glabrum) (western redcedar Thuja plicata

Northern British Columbia, University of

242

All herbaceaous species found at Trillium Trail  

E-print Network

Rosaceae Prunus virginiana chokecherry Rosaceae Quercus alba white oak Fagaceae Quercus rubra northern red oak Fagaceae Frangula alnus alder buckthorn Rhamnaceae Rhododendron rhododendron Ericaeae Rubus spp radicans poison ivy Anacardiaceae #12;Tsuga canadensis eastern hemlock Pinaceae Ulmus rubra slippery elm

Kalisz, Susan

243

Estimation of heritability, evolvability and genetic correlations of two pollen and pistil traits involved in a sexual conflict over timing of stigma receptivity in Collinsia heterophylla (Plantaginaceae)  

PubMed Central

Background and Aims Heritable genetic variation is crucial for selection to operate, yet there is a paucity of studies quantifying such variation in interactive male/female sexual traits, especially those of plants. Previous work on the annual plant Collinsia heterophylla, a mixed-mating species, suggests that delayed stigma receptivity is involved in a sexual conflict: pollen from certain donors fertilize ovules earlier than others at the expense of reduced maternal seed set and lower levels of pollen competition. Methods Parent–offspring regressions and sib analyses were performed to test for heritable genetic variation and co-variation in male and female interactive traits related to the sexual conflict. Key Results Some heritable variation and evolvability were found for the female trait (delayed stigma receptivity in presence of pollen), but no evidence was found for genetic variation in the male trait (ability to fertilize ovules early). The results further indicated a marginally significant correlation between a male's ability to fertilize early and early stigma receptivity in offspring. However, despite potential indirect selection of these traits, antagonistic co-evolution may not occur given the lack of heritability of the male trait. Conclusions To our knowledge, this is the first study of a plant or any hermaphrodite that examines patterns of genetic correlation between two interactive sexual traits, and also the first to assess heritabilities of plant traits putatively involved in a sexual conflict. It is concluded that the ability to delay fertilization in presence of pollen can respond to selection, while the pollen trait has lower evolutionary potential. PMID:22645118

Madjidian, Josefin A.; Andersson, Stefan; Lankinen, Åsa

2012-01-01

244

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

PubMed Central

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

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

2009-01-01

245

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

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.

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

1986-01-01

246

Toxicosis in dairy cattle exposed to poison hemlock (Conium maculatum) in hay: isolation of Conium alkaloids in plants, hay, and urine.  

PubMed

Cattle in two herds developed signs of bloating, increased salivation and lacrimation, depression, respiratory distress, ataxia, and death after ingestion of hay that contained large amounts of poison hemlock (Conium maculatum). Twenty of 30 Angus cows and calves were affected in the first herd (2 died). In the second herd, 5 of 30 Holstein heifers were affected (1 died). The Conium alkaloids, coniine and gamma-coniceine, were quantified in the hay, the plants from the responsible hayfield, and the urine of affected animals. PMID:1554771

Galey, F D; Holstege, D M; Fisher, E G

1992-01-01

247

Biochemical Systematlcsand Ecology,Vol. 18,No. 4, pp. 267-280, 1990. 0305-1978/90 $3.00+ 0.00 Printed in GreatBritain. 1990PergamonPressplc.  

E-print Network

heterophylla), the shore pine race (mainly on Pinus contorta ssp. contorta) and the mountain hemlock race Ill. Shorepine Pinus contorta Tsugaheterophylla ssp. contorta Pinus monttcola of the three purported TsugamertensJana Abies amabifis Pinus monticola Abies procera Piceasitchensis II. Mountain hemlock

Nickrent, Daniel L.

248

76 FR 74018 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Southern...  

Federal Register 2010, 2011, 2012, 2013, 2014

...primarily occupy old-growth western red cedar (Thuja plicata)/hemlock (Tsuga...increase in the distribution of western red cedar (Thuja plicata) in the mid-term...old-growth western hemlock/ western red cedar forests and subalpine fir and...

2011-11-30

249

A Comparative Toxicity Assessment of Materials Used in Aquatic Construction  

Microsoft Academic Search

Comparative toxicity testing was performed on selected materials that may be used in aquatic construction projects. The tests\\u000a 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

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

250

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

USGS Publications Warehouse

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.

Ager, Thomas A.; Rosenbaum, Joseph G.

2009-01-01

251

Range expansion and population dynamics of co-occurring invasive herbivores  

Microsoft Academic Search

Although a range of studies have suggested that competition plays a critical role in determining herbivore assemblages, there\\u000a has been little work addressing the nature of interactions between competing invasive herbivores. We report the results of\\u000a research on the hemlock woolly adelgid Adelges tsugae (‘HWA’) and elongate hemlock scale Fiorinia externa (‘EHS’), invasive herbivores that both feed on eastern hemlock

Evan L. Preisser; Alexandra G. Lodge; David A. Orwig; Joseph S. Elkinton

2008-01-01

252

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

USGS Publications Warehouse

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.

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

2005-01-01

253

Ectomycorrhizal fungal community structure across a bog-forest ecotone in southeastern Alaska.  

PubMed

We examined the ectomycorrhizal (ECM) fungal community across a bog-forest ecotone in southeastern Alaska. The bog and edge were both characterized by poorly drained Histosols and a continuous layer of Sphagnum species, ericaceous shrubs, Carex species, and shore pine [Pinus contorta Dougl. ex Loud. var. contorta]. The forest had better-drained Inceptisols and Spodosols, a tree community comprised of western hemlock [Tsuga heterophylla (Raf.) Sarg.], yellow cedar (Thuja plicata Donn ex D. Don.), Sitka spruce [Picea sitchensis (Bong.) Carr.] and shore pine, and an understorey of ericaceous shrubs and herbs. ECM root tip density (tips cm(-3) soil) was significantly greater in the forest than the edge or bog and ECM colonization was significantly different in all three plant communities. The below ground ECM fungal taxa were analyzed using molecular techniques (PCR-RFLP and DNA sequencing). Three ECM fungal taxa, Suillus tomentosus (Kauffman) Singer, Cenococcum geophilum Fr.:Fr, and a Russula species, differed in relative frequency, yet were among the four most frequent in all three plant communities. Although differences in ECM fungal richness were observed across plant communities, unequal sampling of ECM roots due to root density and colonization differences confounded richness comparisons. Using resampling procedures for creating taxon-accumulation curves as a function of sampled ECM roots revealed similarities in cumulative ECM fungal taxa richness across the ecotone. PMID:14999551

Wurzburger, Nina; Hartshorn, Anthony S; Hendrick, Ronald L

2004-12-01

254

Emission of biogenic VOCs from trees in the Lower Fraser Valley, B.C.  

SciTech Connect

Biogenic volatile organic compounds (VOC`s) are known to participate in the formation of ground level ozone. It is possible that in the areas with high emission rates from local vegetation, biogenic hydrocarbons can be of comparable importance to anthropogenic hydrocarbons in the production of this secondary air pollutant. In order to implement an effective abatement strategy, the relative importance of these biogenic emissions to the atmospheric chemistry of an area must be known. The Lower Fraser Valley located in the southwestern corner of British Columbia experiences episodes of elevated ground level ozone concentrations during the summer under the influence of a stationary high pressure system and characterized by lush coastal rain forest vegetation and extensive agriculture surfaces. During the summer of 1995 a field campaign to determine the emission rate from natural sources in the region was conducted. The emission rate from natural sources in the region was conducted. The mission rate of biogenic hydrocarbons from four tree species, Western Red Cedar (Thuja Plicata), Cottonwood (Populus Balsemifera), Douglass Fir (Pseudotsuga Menziesii) and Hemlock (Tsuga Heterophylla) was measured in the field. It was found that Cottonwood trees emit isoprene at a rate approaching 100 times greater than any of the other three species.

Drewitt, G.; Styen, D.G. [Univ. of British Columbia, Vancouver (Canada); Gillespie, T.; Curren, K. [Univ. of Guelph, Ontario (Canada)

1996-12-31

255

Stomatal behavior of four woody species in relation to leaf-specific hydraulic conductance and threshold water potential.  

PubMed

Midday stomatal closure is mediated by the availability of water in the soil, leaf and atmosphere, but the response to these environmental and internal variables is highly species specific. We tested the hypothesis that species differences in stomatal response to humidity and soil water availability can be explained by two parameters: leaf-specific hydraulic conductance (K(L)) and a threshold leaf water potential (Psi(threshold)). We used a combination of original and published data to estimate characteristic values of K(L) and Psi(threshold) for four common tree species that have distinctly different stomatal behaviors: black cottonwood (Populus trichocarpa Torr. & Gray.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), red alder (Alnus rubra Bong.) and western hemlock (Tsuga heterophylla (Raf.) Sarg.). We used the values to parameterize a simple, nonelastic model that predicts stomatal conductance by linking hydraulic flux to transpirational flux and maintaining Psi(leaf) above Psi(threshold). The model successfully predicted fundamental features of stomatal behavior that have been reported in the literature for these species. We conclude that much of the variation among the species in stomatal response to soil and atmospheric water deficits can be explained by K(L) and Psi(threshold). The relationship between Psi(threshold) and xylem vulnerability to cavitation differed among these species. PMID:12651540

Bond, Barbara J.; Kavanagh, Kathleen L.

1999-07-01

256

SPILOGALE GRACILIS IN UPLAND FORESTS OF WESTERN WASHINGTON AND OREGON  

Microsoft Academic Search

During surveys of upland forests in the Tsuga heterophylla Zone in Washington and Oregon, 1986 to 1996, we caught 192 S. gracilis. In the Oregon Coast Range, more (85%) S. gracilis were caught in oldeilar to Coast Range old growth (P = 0.60) with no differences between seral stages (P = 0.74). No S. gracilis were caught in upland forests

ANDREW B. CAREY; JANET E. KERSHNER

1996-01-01

257

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...

258

Ordination of epiphytic bryophyte communities in a wet-temperate coniferous forest, South-Coastal British Columbia  

Microsoft Academic Search

Three coniferous tree species (Pseudotsuga menziesii, Tsuga heterophylla, and Thuja plicata) at Capilano Canyon, British Columbia, were studied for their epiphytic communities. Quantitative data were obtained for fourteen bryophyte species by sampling at heights of 0.5 m, 1 m and 2 m above ground level. Scapania bolanderi is an abundant and widely distributed species; Dicranum fuscescens, Bazzania denudata, Lepidozia reptans

N. C. Kenkel; G. E. Bradfield

1981-01-01

259

Occurrence and dominance of six Pacific Northwest conifer species Todd A. Schroeder, Andreas Hamann, Tongli Wang & Nicholas C. Coops  

E-print Network

conifer species (Pseudotsuga menziesii, Tsuga heterophylla, Pinus contorta, Thuja plicata, Larix.001) and Thuja plicata lowest (r 5 0.038, P 5 0.799). At the 50-km scale, correlations between dominance the high- est correlation (r 5 0.68, Po0.001) and Thuja plicata the lowest (r 5 0.07, P40.709). Conclusions

Hamann, Andreas

260

Canopy vegetation influences ant (Hymenoptera: Formicidae) communities in headwater stream riparian zones of central Appalachia.  

PubMed

In the eastern United States, eastern hemlock Tusga canadensis (L.) Carriere forests are threatened by the invasive hemlock woolly adelgid, Adelges tsugae, a pest that is causing widespread hemlock mortality. Eastern hemlock is an essential component of forested communities. Adelgid-induced hemlock mortality is causing a shift in forest composition and structure, altering ecosystem function and thereby influencing the arthropod community. Using pitfall traps at three sites, we monitored ground-dwelling arthropods at 30-d intervals in hemlock-dominated and deciduous-dominated forests in central Appalachia over 2 yr. Here, we focus on the ant community (Hymenoptera: Formicidae) collected in the summer months. Ants form a ubiquitous and integral component of the invertebrate community, functioning at various trophic levels as predators, herbivores, and omnivores, and fulfilling important roles in forest ecosystems. We found no difference in overall ant abundance between hemlock-dominated and deciduous-dominated forests but did detect significant differences in the genera Prenolepis between forest types (P < 0.01) and Aphaenogaster across study locations (P?=?0.02). Three genera were unique to deciduous forests; one was unique to hemlock forests. Not surprisingly, total formicids and several genera demonstrated temporal differences in abundance, with greater numbers captured in July than in August. As hemlock woolly adelgid-induced mortality of eastern hemlock becomes more pervasive, changes in forest composition and structure are imminent, accompanied by shifts in hemlock associates. PMID:25528753

Johnson, Jonathan T; Adkins, Joshua K; Rieske, Lynne K

2014-01-01

261

The Importance of Large-Diameter Trees to Forest Structural Heterogeneity  

PubMed Central

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

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

2013-01-01

262

The importance of large-diameter trees to forest structural heterogeneity.  

PubMed

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 m(2). Basal area of the 26 woody species was 62.18 m(2)/ha, of which 61.60 m(2)/ha was trees and 0.58 m(2)/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

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

2013-01-01

263

Economic impact of log grade on the production of plywood and lumber  

E-print Network

trees. The study is similar to the two previously cited studies. Studies by Woodfin and Snellgrove (16), reporting on lumber and residue recovery from western hemlock (T~ heterophylla) in southeast Alaska, and by Plank (17) reporting yields f P d Pi...

Ledford, Donald Wayne

1986-01-01

264

Holocene vegetational history of the Kootenai River Valley, Montana  

NASA Astrophysics Data System (ADS)

Pollen records in the Kootenai and Fisher River drainages in western Montana reveal a fivezone sequence of Holocene vegetation change. Deposition of Glacier Peak Ash-Layer G (ca. 10,540 ± 660 yr B.P.) in the lowermost sediments (clay intermixed with pebbles) at Tepee Lake gives a minimum date for the initiation of sedimentation. Initial vegetation on the newly deglaciated terrain was dominated by Pinus (probably white bark pine) with small amounts of Gramineae, Picea and Abies, reflecting a relatively cool, moist macroclimate. Two vegetation units appear to contribute to Pollen Zone II (ca. 11,000-7100 yr B.P.): arboreal communities with pines, along with Pseudotsuga or Larix, or both, and treeless vegetation dominated by Artemisia. Pollen Zone II represents an overall warmer macroclimate than occurred upon ice withdrawal. After ca. 7100 yr B.P. (Pollen Zone III) diploxylon pines became a major pollen contributor near both Tepee Lake and McKillop Creek Pond, indicating an expansion of xerophytic forest ( P. contorta and P. ponderosa) along with an increase in the prominence of Pseudotsuga menziesii or Larix occidentalis, or both. Artemisia briefly expanded coverage near Tepee Lake concomitant with the Mazama ashfall ca. 6700 yr B.P. A short-term climatic trend with more available water began after ca. 4000 yr B.P. as Abies (probably A. grandis) along with Picea engelmannii became a more regular component of the forest surrounding both sites. Emergence of the modern macroclimate is indicated primarily with the first regular appearance of Tsuga heterophylla in the pollen record by ca. 2700 yr B.P., synchronous with the development of western hemlock forest within the same latitudes in northern Idaho and northeastern Washington.

Mack, Richard N.; Rutter, N. W.; Valastro, S.

1983-09-01

265

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

USGS Publications Warehouse

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).

Sohl, Terry L.

2012-01-01

266

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

Microsoft Academic Search

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

L. J. Puckett

1982-01-01

267

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

268

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

269

Deer impacts on forest ecosystems: a North American perspective  

Microsoft Academic Search

Summary White-tailed deer have increased in abundance and expanded their geographic range in North America over the past century, and now exist at higher densities than they have in the past several hundred years. This is having numerous impacts on the forest ecosystems they inhabit. Regional recruitment failure of eastern hemlock (Tsuga canadensis) and northern white cedar (Thuja occidentalis) trees

T. P. Rooney

2001-01-01

270

Ecology, 82(12), 2001, pp. 33303345 2001 by the Ecological Society of America  

E-print Network

of a subalpine conifer, mountain hemlock (Tsuga mertensiana). Tree-ring chronologies were developed for 31 sites atmospheric CO2 concentrations could produce warmer temperatures and reduced snowpack depths in the next the next century in response to a doubling of atmospheric CO2 concentrations (Watson et al. 1996). Changes

Wallin, David O.

271

Microbial utilization of dissolved organic carbon leached from riparian litterfall  

Microsoft Academic Search

Dissolved organic carbon (DOC) in aquatic systems is abundant and used within stream food webs, but DOC quality is rarely studied. DOC in the leachates from the litter of five tree species (red alder, Alnus rubra; vine maple, Acer circinatum; western red cedar, Thuja plicata; western hemlock, Tsuga hetrophylla; and Douglas-fir, Pseudotsuga menziesii) were assessed for their chemistry and relative

Michael D. McArthur; John S. Richardson

2002-01-01

272

Appendix C. Habitat Summaries for Ecologies Common to the Pacific Northwest Montane Mixed Conifer Forest  

E-print Network

woodland, dominated by evergreen conifers. Canopy structure varies from single- to multi-storied. Tree size amabilis), mountain hemlock (Tsuga mertensiana), subalpine fir (A. lasiocarpa), Shasta red fir (A. magnific var. shastensi), Engelmann spruce (Picea engelmannii), noble fir (A. procera), or Alaska yellow-cedar

273

Common name Scientific name  

E-print Network

T Other Softwoods Eastern red cedar Juniperus virginiana NT 1 S S­I I Eastern hemlock Tsuga canadensis T 1 to western Virginia. CharacteristicsofCommonWesternVirginiaTrees Publication 420-351 www.ext.vt.edu Produced in which healthy communities of trees and other vegetation are es- tablished and maintained for the benefit

Liskiewicz, Maciej

274

Dendrochronological Mass Balance Reconstruction, Strathcona Provincial Park, Vancouver Island, Briti  

Microsoft Academic Search

A long-term proxy record of glacier mass balance was developed for Colonel Foster and Septimus glaciers on Vancouver Island, British Columbia, Canada. This was accomplished by analyzing the radial growth characteristics of climatically-sensitive mountain hemlock trees (Tsuga mertensiana), and by comparing this response with mass balance records from four glaciers in the Pacific Northwest. A strong (negative) relationship between the

Dave Lewis

275

Dendrochronological Mass Balance Reconstruction, Strathcona Provincial Park, Vancouver Island, British Columbia, Canada  

Microsoft Academic Search

A long-term proxy record of glacier mass balance was developed for Colonel Foster and Septimus glaciers on Vancouver Island, British Columbia, Canada. This was accomplished by analyzing the radial growth characteristics of climatically-sensitive mountain hemlock trees (Tsuga mertensiana), and by comparing this response with mass balance records from four glaciers in the Pacific Northwest. A strong (negative) relationship between the

Dave Lewis; Dan Smith

2004-01-01

276

Nitrogen cycling in a northern hardwood forest: Do species matter?  

Microsoft Academic Search

To investigate the influence of individual tree species on nitrogen (N) cycling in forests, we measured key characteristics of the N cycle in small single-species plots of five dominant tree species in the Catskill Mountains of New York State. The species studied were sugar maple (Acer saccharum), American beech (Fagus grandifolia), yellow birch (Betula alleghaniensis), eastern hemlock (Tsuga canadensis), and

Gary M. Lovett; Kathleen C. Weathers; Mary A. Arthur; Jack C. Schultz

2004-01-01

277

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

278

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

279

Vesicular mycorrhizal colonization of seedlings of Pinaceae and Betulaceae after spore inoculation with Glomus intraradices  

Microsoft Academic Search

Although Pinaceae and Betulaceae have been reported to contain Glomus–type root endophytes, its ecological importance and the conditions influencing this symbiosis are poorly understood. Seedlings\\u000a of Abies lasiocarpa, Alnus rubra, Pinus contorta, Pinus ponderosa, Pseudotsuga menziesii, and Tsuga heterophylla were inoculated with Glomus intraradices to determine the vesicular-arbuscular mycorrhizae (VAM) development and responsiveness of these hosts. The role of companion

J. E. Smith; K. A. Johnson; E. Cázares

1998-01-01

280

Structure and dynamics of an ancient montane forest in coastal British Columbia  

Microsoft Academic Search

Old-growth forests are common in the snowy, montane environments of coastal western North America. To examine dynamics of a stand containing four canopy tree species ( Abies amabilis, Chamaecyparis nootkatensis, Tsuga mertensiana and T. heterophylla), we used four stem-mapped, 50 m ×50 m plots. From measurements of annual rings, we obtained ages from basal discs of 1,336 live trees, developed master chronologies

Roberta Parish; Joseph A. Antos

2004-01-01

281

Successional trends and biomass of mosses on windthrow mounds in the temperate rainforests of Southeast Alaska  

Microsoft Academic Search

We investigated successional trends on windthrow mounds in two old-growth Tsuga heterophylla-Picea sitchensis forests in northern southeast Alaska to determine the influence of windthrow disturbance on the maintenance of plant diversity. We were particularly interested in assessing the value of mosses in detecting long-term effects of disturbance in temperate rainforests. Mosses established a dense carpet on windthrow mounds within the

Jan den Ouden; Paul B. Alaback

1996-01-01

282

Predicted short-term radial-growth changes of trees based on past climate on Vancouver Island, Briti  

Microsoft Academic Search

Tree-ring radial expansion estimator (TREE) is an integrated radial growth model that allows users to define short-term climate change scenarios to anticipate the impact upon mature trees found growing at high elevation on Vancouver Island, British Columbia. Five individualistic models were built to represent the radial growth behaviour of mountain hemlock (Tsuga mertensiana (Bong. ) Carr), yellow-cedar (Chamaecyparis nootkatensis (D.

Colin P. Laroque; Dan J. Smith

283

Predicted short-term radial-growth changes of trees based on past climate on Vancouver Island, British Columbia  

Microsoft Academic Search

Tree-ring radial expansion estimator (TREE) is an integrated radial growth model that allows users to define short-term climate change scenarios to anticipate the impact upon mature trees found growing at high elevation on Vancouver Island, British Columbia. Five individualistic models were built to represent the radial growth behaviour of mountain hemlock (Tsuga mertensiana (Bong.) Carr), yellow-cedar (Chamaecyparis nootkatensis (D. Don)

Colin P. Laroque; Dan J. Smith

2005-01-01

284

HIERARCHICAL COMPARISONS OF BREEDING BIRDS IN OLD GROWTH CONIFER-HARDWOOD FOREST ON THE APPALACHIAN PLATEAU  

Microsoft Academic Search

I compared relative abundances of breeding birds in old-growth forest (2300 years old) to surrounding landscapes using data from the Breeding Bird Census (BBC) and Breeding Bird Atlas (BBA). Eleven study plots (148 ha total) were established in relict, presettlement hemlock-white pine-northern hardwood (Tsuga canadensis-Pinus strobus) forest on the northern Appalachian Plateau, Pennsylvania. Of 56 breeding species recorded in old-growth

J. CHRISTOPHER HANEY

1999-01-01

285

14. View of the long terrace, illustrating the relationship between ...  

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

14. View of the long terrace, illustrating the relationship between the formal and the natural landscape. Two recent re-planted hemlock hedges (Tsuga canadensis) in the distance obscure the putting green. The view includes the rose garden, the swimming pool retaining wall, the bronze sculpture "Bather at the Seine" by Maillol (Ca. 1921), and the steps ascending to the rock garden. - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

286

54. View of the long terrace, illustrating the relationship between ...  

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

54. View of the long terrace, illustrating the relationship between the formal and the natural landscape. Two recently re-planted hemlock (Tsuga canadensis) in the distant obscure the putting green. The view includes the rose garden, the swimming pool retaining wall, the bronze sculpture "Bather at the Seine" by Maillol (Ca. 1921), and the steps ascending to the rock garden. - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

287

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

288

Using Imidacloprid to Control Hemlock Woolly Adelgid  

Microsoft Academic Search

The chloronicotinyl insecticide imidacloprid has become one of the most widely used insecticides in the world based on its unique mode of action, its excellent activity towards a wide range of pests, and its favorable toxicological and environmental profiles. In the United States, imidacloprid has established an excellent reputation for insect control on turf and ornamentals and this active ingredient

Charles A. Silcox

289

Plants determine diversity and function of soil microbial and mesofaunal communities - results from a girdling experiments in a temperate coniferous forest  

NASA Astrophysics Data System (ADS)

The potential for carbon (C) sequestration in soils depends on the rate of humification of C inputs to soils in relation to the decomposition of old soil organic matter. Recent results indicate a close connection between the input of fresh organic matter and the decomposition of old organic matter through soil priming. We conducted a tree girdling experiment in order to better understand the interdependence of soil microbial communities and plant belowground C allocation. A girdling experiment in a mature Western Hemlock (Tsuga heterophylla) stand near York (NE England) confirms the pattern observed in other girdling studies, with a reduction in total soil CO2 efflux (RS) to about 60% of control plots following a delay of about 2 weeks. High frequency measurements of RS immediately after girdling show a short-lived significant increase in RS in girdled plots between 3 and 8 hours after tree girdling, which have not been observed previously. The autotrophic flux contribution (calculated as the difference in RS between the control and girdled plots) declined throughout autumn, but in contrast to most girdling studies, remained significantly greater than zero throughout during December and January. This result indicates that tree belowground allocation continues throughout winter, despite regular night-time frosts in the period measurement were taken. Dominant mesofauna invertebrates (Enchytraeid worms) showed a positive response to girdling and higher abundances were recorded in the girdled plots when compared to the control ones, although differences were only significant on one sampling occasion. These results suggest that, in contrast to other components of the soil food-web, these organisms appear to be underpinned by detrital decomposition rather than by recent photosynthate-C deposition. Litterbag incubations showed no significant short-term treatment effect over the 4 months period following girdling, indicating no measurable interaction of decomposition and plant activity by this method. The results emphasise the strong influence of plants on the composition and activity of microbial soil communities. This has clear implications for our ability to predict ecosystem response to environmental change, including shifts in land use managements, and we discuss the need of incorporating these effects into current ecosystem models.

Subke, J.; Voke, N.; Leronni, V.; Briones, M. J. I.; Ineson, P.

2009-04-01

290

Dynamic variation in sapwood specific conductivity in six woody species.  

PubMed

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

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

2007-10-01

291

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)

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.

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

2008-12-01

292

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

PubMed

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

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

2004-05-01

293

GENETICS AND CONSERVATION OF HEMLOCK SPECIES THREATENED BY THE HEMLOCK WOOLLY ADELGID  

Microsoft Academic Search

Camcore is a forestry research cooperative program housed in the Department of Forestry and Environmental Resources at North Carolina State University, specializing in the applied conservation and domestication of forest genetic resources utilizing an ex situ approach. We make genetically representative seed collections from populations of threatened and endangered tree species that cannot be reliably conserved in their natural environment

Robert Jetton; William Dvorak; Andrew Whittier; Kevin Potter; Rusty Rhea

2009-01-01

294

Modern pollen rain and vegetational history of the Malaspina Glacier district, Alaska  

NASA Astrophysics Data System (ADS)

Seventy surface pollen samples from coastal forest, coastal meadow, muskeg, tree line, and alpine tundra communities form a basis for interpreting fossil pollen assemblages in the Malaspina Glacier district, Alaska. Poflen and macrofossil analyses of three radiocarbon-dated fossil sections from Icy Cape indicate that vegetational changes resulting from plant succession can be distinguished from those of migrational and climatic origin. Vegetation of the early Holocene xerothermic interval (10,000-7600 yr B.P.) was dominated by Alnus communities. Wetter conditions ensued, enabling generative muskeg surfaces to develop and first Picea sitchensis, then Tsuga heterophylla to expand from areas southeastward. Climatic cooling in more recent millennia (3500 yr B.P. to the present) is indicated by the appearance and persistent growth of Tsuga mertensiana and Selaginella selaginoides along this portion of the Gulf of Alaska coastline.

Peteet, Dorothy M.

1986-01-01

295

Deer herbivory alters forest response to canopy decline caused by an exotic insect pest.  

PubMed

Hemlock woolly adelgid (HWA; Adelges tsugae) infestations have resulted in the continuing decline of eastern hemlock (Tsuga canadensis) throughout much of the eastern United States. While the initial impacts of HWA infestations have been documented, our understanding of forest response to this disturbance remains incomplete. HWA infestation is not occurring in isolation but within a complex ecological context. The role of potentially important interacting factors, such as elevated levels of white-tailed deer herbivory, is poorly understood. Despite the potential for herbivory to alter forest successional trajectories following a canopy disturbance, little is known about herbivory-disturbance interactions, and herbivory is rarely considered in assessing forest response to a co-occurring disturbance. We used repeated censuses of deer exclosures and paired controls (400 paired plots) to quantify the impact of deer herbivory on tree seedling species abundance in 10 eastern hemlock ravines that span a gradient in HWA-induced canopy decline severity. Use of a maximum likelihood estimation framework and information theoretics allowed us to quantify the strength of evidence for alternative models developed to estimate the impacts of herbivory on tree seedling abundance as a function of varying herbivore density and canopy decline severity. The exclusion of deer herbivory had marked impacts on the abundance of the studied seedling species: Acer rubrum, Acer saccharum, Betula lenta, Nyssa sylvatica, Quercus montana, and Tsuga canadensis. For all six species, the relationship between seedling abundance and deer density was either exponential or saturating. Although the functional form of the response varied among seedling species, the inclusion of both deer density and canopy decline severity measures consistently resulted in models with substantially greater support. Canopy decline resulted in higher proportional herbivory impacts and altered the ranking of herbivory impacts by seedling species. Our results suggest that, by changing species' competitive abilities, white-tailed deer herbivory alters the trajectory of forest response to this exotic insect pest and has the potential to shift future overstory composition. PMID:18488602

Eschtruth, Anne K; Battles, John J

2008-03-01

296

Late Quaternary dynamics of forest vegetation on northern Vancouver Island, British Columbia, Canada  

NASA Astrophysics Data System (ADS)

Pollen analysis of radiocarbon-dated lake sediment from northern Vancouver Island, southwest British Columbia reveals regional changes in forest vegetation over the last 12,200 14C yr (14,900 cal yr). Between at least 12,200 and 11,700 14C yr BP (14,900-13,930 cal yr BP), open woodlands were dominated by Pinus contorta, Alnus crispa, and various ferns. As P. contorta decreased in abundance, Alnus rubra and more shade-tolerant conifers (i.e., Picea and Tsuga mertensiana) increased. Increases in T. mertensiana, P. contorta, and A. crispa pollen accumulation rates (PARs) between 10,600 and 10,400 14C yr BP (11,660-11,480 cal yr BP) reflect a cool and moist climate during the Younger Dryas chronozone. Orbitally induced warming around 10,000 14C yr BP (11,090 cal yr BP) allowed the northward extension of Pseudotsuga menziesii, although Picea, Tsuga heterophylla, and A. rubra dominated early Holocene forests. By 7500 14C yr BP (8215 cal yr BP), shade-tolerant T. heterophylla was the dominant forest tree. Cupressaceae ( Thuja plicata and Chamaecyparis nootkatensis) was present by 7500 14C yr BP but reached its maximum after 3500 14C yr BP (3600 cal yr BP), when a cooler and wetter regional climate facilitated the development of temperate rainforest. The highest rates of vegetation change are associated with Lateglacial climate change and species with rapid growth rates and short life spans.

Lacourse, Terri

2005-01-01

297

Fire Regimes of the Southern Appalachian Mountains: Temporal and Spatial Variability and Implications for Vegetation Dynamics  

E-print Network

1997). One notion is that fires ignited by humans and possibly lightning were common across eastern North America prior to Euro-American settlement (e.g. Abrams 1992, Frost 1998 , Brose et al. 2001) and that aboriginal burning practices were adopted... America (Lorimer 1984, Nowacki and Abrams 1992, Harrod et al. 2000, McEwan and Muller 2006, Fei et al. 2011). Species composition has shifted toward mesophytic trees like maple (Acer L.), birch (Betula L.) and hemlock (Tsuga Carri?re). Nowacki...

Flatley, William 1977-

2012-08-31

298

Aversive responses of white-tailed deer,Odocoileus virginianus, to predator urines.  

PubMed

We tested whether predator odors could reduce winter browsing of woody plants by white-tailed deer (Odocoileus virginianus). Urine from bobcats (Lyra rufus) and coyotes (Canis latrans) significantly reduced browsing of Japanese yews (Taxus cuspidata), and repellency was enhanced when urine was reapplied weekly as a topical spray. Urine of cottontail rabbits (Sylvilagus floridanus) and humans did not reduce damage, suggesting that deer do not respond aversively to odors of nonpredatory mammals or occasional predators with which they lack a long evolutionary association. Bobcat and coyote urine were more effective in tests conducted with eastern hemlock (Tsuga canadensis), which is less palatable to white-tailed deer than Japanese yew. A dichloromethane extract of bobcat urine was as effective as unextracted urine in reducing damage to hemlocks. Testing of the organic components of bobcat urine, particularly the volatile components, may enable identification of the compounds responsible for the repellency we observed. PMID:24258921

Swihart, R K; Pignatello, J J; Mattina, M J

1991-04-01

299

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

PubMed

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

Orwig, David A; Barker Plotkin, Audrey A; Davidson, Eric A; Lux, Heidi; Savage, Kathleen E; Ellison, Aaron M

2013-01-01

300

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

PubMed Central

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

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

2013-01-01

301

ORIGINAL PAPER Changes in the regional abundance of hemlock associated  

E-print Network

, PA 19073, USA e-mail: rsmorin@fs.fed.us S. N. Oswalt Southern Research Station Forest Inventory some invasive species such as beech bark disease have predominantly altered stand structure (Garnas et

Liebhold, Andrew

302

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

PubMed

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

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

2015-02-01

303

THE INFLUENCE OF SUCCESSIONAL PROCESSES AND DISTURBANCE ON THE STRUCTURE OF TSUGA CANADENSIS FORESTS  

Microsoft Academic Search

Old-growth forests are valuable sources of ecological, conservation, and management information, yet these ecosystems have received little study in New England, due in large part to their regional scarcity. To increase our understanding of the structures and processes common in these rare forests, we studied the abundance of downed coarse woody debris (CWD) and snags and live-tree size-class distributions in

Anthony W. D'Amato; David A. Orwig; David R. Foster

2008-01-01

304

A comparative toxicity assessment of materials used in aquatic construction.  

PubMed

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

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

2011-10-01

305

Reconstruction of annual temperature (1590?1979) for Longmire, Washington, derived from tree rings  

NASA Astrophysics Data System (ADS)

Annual growth records from trees at timberline in the Cascade Range of Washington are correlated with variations in temperature and snow depth and used to reconstruct climatic variation in the past. Response surfaces indicate that growth of mountain hemlock ( Tsuga mertensiana) and subalpine larch ( Larix lyallii) is positively correlated with summer (July to September) temperature and negatively correlated with spring (March) snow depth when snow depth is at or below average. During years of above average snow depth, temperature has little effect on mountain hemlock but has a negative effect on growth in subalpine larch. These interactions make it difficult to reconstruct these climatic variables separately using standard methods. Mean annual temperature values, which combine information on both summer temperature and spring snow depth, were estimated from a regression model that reconstructs past temperature at Longmire, Washington, as a function of larch and hemlock tree-ring chronologies. The reconstruction of mean annual temperature shows temperatures between 1590 and 1900 to be approximately 1°C lower than those of the 20th century. Only during a short period from 1650 to 1690 did temperatures approach 20th-century values.

Graumlich, Lisa J.; Brubaker, Linda B.

1986-03-01

306

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

DOEpatents

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.

Lewis, Norman G. (Pullman, WA); Davin, Laurence B. (Pullman, WA); Dinkova-Kostova, Albena T. (Baltimore, MD); Fujita, Masayuki (Kita-gun, JP), Gang; David R. (Ann Arbor, MI), Sarkanen; Simo (Minneapolis, MN), Ford; Joshua D. (Pullman, WA)

2003-10-21

307

Effects of temperature and photoperiod on the aestivo-hibernal egg diapause of Scymnus camptodromus (Coleoptera: Coccinellidae).  

PubMed

Three sequential studies were conducted on the interacting effects of exposure to low (5°C) temperature for 0, 7, 28, 56, or 84 d followed by incubation at 10, 15, or 20°C on the egg diapause of Scymnus (Neopullus) camptodromus Yu and Liu (Coleoptera: Coccinellidae). This beetle was imported from China as a potential biological control agent for hemlock woolly adelgid, Adelges tsugae (Annand) (Hemiptera: Adelgidae). Very few eggs laid and held at a constant 15 or 20°C showed any indication of development. Only eggs exposed to temperature combinations of 5 and 10°C had >50% hatch. Highest percent hatch and fastest development occurred when eggs were held at 5°C for 56 or 84 d followed by holding at 10°C. A model estimated the lower threshold for postdiapause development to be 2°C. The effect of temperature on egg hatch was similar at photoperiods of 12:12 and 16:8 (L:D) h, suggesting egg development is not governed by photoperiod or light exposure. Collectively these data indicate that S. camptodromus eggs laid in the spring and summer go through an aestivo-hibernal diapause that is maintained by warm temperatures and that development resumes when temperatures drop, in parallel with the development of hemlock woolly adelgid. This concurrent development allows S. camptodromus eggs to hatch while hemlock woolly adelgid is laying eggs. This synchrony between the development of S. camptodromus eggs and the overwintering adelgid suggest this beetle may be a good candidate for the biological control of the hemlock woolly adelgid. PMID:23321116

Keena, Melody A; Trotter, R Talbot; Cheah, Carole; Montgomery, Michael E

2012-12-01

308

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

PubMed

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

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

2011-06-01

309

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)

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.

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

2012-11-01

310

Spatial variation of modern pollen in Oregon and southern Washington, USA.  

PubMed

Surface sediments from 95 lakes provide information on the spatial variation of modern pollen spectra in Oregon and southern Washington. Percentages for 13 pollen types were compared within and between vegetation zones to characterize regional patterns of pollen spectra. The percentage data were also compared with climate variables to determine relationships between pollen percentages and regional climate gradients. The composition of modern pollen spectra corresponds well with the distribution of the pollen producers. Most pollen assemblages were generally dominated by Pinus, but those west of the Cascade Range were dominated by Alnus. Low percentages of Pseudotsuga/Larix, Tsuga mertensiana, Abies, and Picea pollen coincided with local occurrence of the trees. The distributions of the pollen data were arranged along gradients of temperature and effective moisture. West of the Cascade Range, Alnus, Tsuga heterophylla, Pseudotsuga/Larix, and Cupressaceae pollen were abundant and correlate well with moderate temperature and high effective moisture. In the shrub-steppe and woodlands east of the Cascade Range, where effective moisture is low, Artemisia, Cupressaceae, and Pinus pollen were dominant. At high elevations, Pinus, T. mertensiana, Abies, and Picea were common pollen types in areas with short growing seasons and high effective moisture. Pollen percentages collected from lake surface sediments, moss polsters, and soils were compared within a number of vegetation types to assess their similarity. The three types of sample yielded similar results for forested areas, but lake sediment samples from upper- and lower-treeline sites captured a more regional picture of the vegetation. PMID:11042328

Minckley; Whitlock

2000-10-01

311

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

USGS Publications Warehouse

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.

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

1995-01-01

312

Responses of plants to simulated saline drift as affected by species and conditions of exposure.  

PubMed

In exposures to simulated saline drift generated from a 0.6% (w/w) chloride (Cl)-solution, under controlled environmental conditions, the median effective doses for the occurrence of any salt-induced foliar injury (expressed as microgCl cm(-2) deposited in six hours) were: 2.9 for Canada hemlock (Tsuga canadensis [L.] Carr.); 10.3 for white flowering dogwood (Cornus florida L.); 43.5 for potato (Solanum tubersum L. cv Superior); 44.2 for northern red oak (Quercus rubra L.); 65.1 for sweet corn (Zea mays L. cv Golden Cross Bantam); and, 123 for bush bean (Phaseolus vulgaris L. cv Pinto). Response of bean was a function of total deposition and independent of its rate with multiple (one per day) 6-h exposures but not with exposures less than 6 h where toxicity (per mass of Cl) increased with an increase in the rate of deposition. Toxicity of particles increased with an increase in the concentration of Cl in the solution (1.6 or 5.0% w/w) from which they were generated with bush bean but not with hemlock. Post-exposure periods that cycled between 50 and 855% relative humidity (RH) produced a greater incidence of salt-induced foliar injury than did a regime of constant 85% RH. PMID:15092146

McCune, D C; Silberman, D H

1991-01-01

313

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

SciTech Connect

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.

Woodward, A.; Silsbee, D.G. [Univ. of Washington, Seattle, WA (United States); Schreiner, E.G. [National Biological Service, Port Angeles, WA (United States)

1995-08-01

314

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....

315

76 FR 76934 - Foreign-Trade Zones 140 and 78; Applications for Subzone Authority; Dow Corning Corporation...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Authority; Dow Corning Corporation, Hemlock Semiconductor Corporation and Hemlock Semiconductor, L.L.C.; Extension of Comment Periods...October 12, 2011), at the Hemlock Semiconductor Corporation facility in Hemlock,...

2011-12-09

316

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Authority, Dow Corning Corporation, Hemlock Semiconductor Corporation, and Hemlock Semiconductor, L.L.C.; Reopening of Comment Periods...63283, 10/12/2011), at the Hemlock Semiconductor Corporation facility in Hemlock,...

2012-05-23

317

77 FR 21082 - Foreign-Trade Zones 140 and 78, Applications for Subzone Authority Dow Corning Corporation...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Authority Dow Corning Corporation, Hemlock Semiconductor Corporation, and Hemlock Semiconductor, L.L.C.; Reopening of Rebuttal Periods...63283, 10/12/2011), at the Hemlock Semiconductor Corporation facility in Hemlock,...

2012-04-09

318

76 FR 81475 - Foreign-Trade Zones 140 and 78 Applications for Subzone Authority Dow Corning Corporation...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Authority Dow Corning Corporation, Hemlock Semiconductor Corporation and Hemlock Semiconductor, L.L.C.; Notice of Public Hearing...63282-63283, 10/12/2011), the Hemlock Semiconductor Corporation facility in Hemlock,...

2011-12-28

319

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

PubMed

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

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

2014-09-01

320

SYSTEMATICS Molecular Validation of a Morphological Character for Distinguishing  

E-print Network

the Armored Scale Insects Chionaspis pinifoliae and Chionaspis heterophyllae (Hemiptera: Diaspididae) DOMINIC heterophyllae Cooley (Hemiptera: Diaspididae) overlap broadly in host range and geographic distribution pinifoliae (Fitch) and Chionaspis heterophyllae Cooley (Hemiptera: Di- aspididae) are important pests

Hanks, Lawrence M.

321

Eastern Hemlock Decline and Persistence of Disjunct Populations Near Its Southern Boundary  

E-print Network

that population size influences extinction, which is not always true. A number of plant and animal species (e distribution theory and assumes when extinction forces arise, a species'range should implode and the last of the particular extinction force rather than population density. Extinction factors often move across

Shawkey, Matthew

322

A novel toxic alkaloid from poison hemlock ( Conium maculatum L., Apiaceae): Identification, synthesis and antinociceptive activity  

Microsoft Academic Search

2-Pentylpiperidine, named conmaculatin, a novel volatile alkaloid related to coniine was identified from the renowned toxic weed Conium maculatum L. (Apiaceae). The structure of conmaculatin was corroborated by synthesis (8 steps starting from cyclohexanol, overall yield 12%). Conmaculatin’s strong peripheral and central antinociceptive activity in mice was observed in a narrow dose range (10–20mg\\/kg). It was found to be lethal

Niko Radulovi?; Nevenka ?or?evi?; Marija Deni?; Mariana Martins Gomes Pinheiro; Patricia Dias Fernandes; Fabio Boylan

323

A novel toxic alkaloid from poison hemlock (Conium maculatum L., Apiaceae): identification, synthesis and antinociceptive activity.  

PubMed

2-Pentylpiperidine, named conmaculatin, a novel volatile alkaloid related to coniine was identified from the renowned toxic weed Conium maculatum L. (Apiaceae). The structure of conmaculatin was corroborated by synthesis (8 steps starting from cyclohexanol, overall yield 12%). Conmaculatin's strong peripheral and central antinociceptive activity in mice was observed in a narrow dose range (10-20mg/kg). It was found to be lethal in doses higher than 20mg/kg. PMID:22063758

Radulovi?, Niko; Dor?evi?, Nevenka; Deni?, Marija; Pinheiro, Mariana Martins Gomes; Fernandes, Patricia Dias; Boylan, Fabio

2012-02-01

324

Induction of cleft palate in newborn pigs by maternal ingestion of poison hemlock (Conium maculatum).  

PubMed

Cleft palates were induced in newborn pigs of gilts fed Conium maculatum seed or plant during gestation days 30 through 45. Twelve of 23 newborn pigs born to 3 gilts given Utah-grown C maculatum seed and 9 of 12 newborn pigs born to a single gilt given the fresh Utah spring-growth C maculatum plant had cleft palates. The cleft palates ranged from a unilateral cleft, involving only 1 side of the palate, to a full bilateral cleft. Brachygnathia was also observed in some of these newborn pigs with cleft palate. Other malformations were not observed. Chemical analysis of seed and plant samples indicated that gamma-coniceine was the responsible teratogenic alkaloid. A daily dose of plant or seed that provided greater than or equal to 1.07 mg of gamma-coniceine/kg of body weight fed to gilts during the 30th through the 45th day of pregnancy resulted in teratogenic effects. PMID:4026015

Panter, K E; Keeler, R F; Buck, W B

1985-06-01

325

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

Microsoft Academic Search

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

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

2003-01-01

326

Response of arthropod biodiversity to foundation species declines: The case of the eastern hemlock  

Microsoft Academic Search

Widespread declines of foundation species, such as many corals, kelps, and overstory trees, are of grave concern because, by definition, these species create and maintain habitat that supports other species. Nevertheless, past responses to their declines, many of which were caused by invasive species, have been late and ineffective, underscoring the need to predict changes in biodiversity and ecosystem function

Jason R. Rohr; Carolyn G. Mahan; Ke Chung Kim

2009-01-01

327

A Bayesian Bioeconometric Model of Invasive Species Control: The Case of the Hemlock Woolly Adelgid  

Microsoft Academic Search

In this article we evaluate a US Forest Service plan to mitigate damages from an invasive insect on public, forested land.\\u000a We develop a dynamic model of infestation and control to explicitly account for biological interactions, baseline conditions,\\u000a and uncertainty, thus creating a more complete picture of policy impacts than a static cost benefit analysis could provide.\\u000a We combine the

Christopher C. Moore; Daniel J. Phaneuf; Walter N. Thurman

2011-01-01

328

Structure and dynamics of an ancient montane forest in coastal British Columbia.  

PubMed

Old-growth forests are common in the snowy, montane environments of coastal western North America. To examine dynamics of a stand containing four canopy tree species (Abies amabilis, Chamaecyparis nootkatensis, Tsuga mertensiana and T. heterophylla), we used four stem-mapped, 50 m x 50 m plots. From measurements of annual rings, we obtained ages from basal discs of 1,336 live trees, developed master chronologies for each species, reconstructed early growth rates, and delineated periods of release. The stand was ancient; individuals of all four species exceeded 900 years in age, and the oldest tree exceeded 1,400 years. The four plots differed in the timing of events, and we found no evidence of major, stand-level disturbance. Instead the stand was structured by small-scale patch dynamics, resulting from events that affected one to several trees and initiated episodes of release and relatively rapid early growth. The species differed in age structure and dynamics. A. amabilis and T. heterophylla had a classical reverse-J age structure indicative of stable populations, whereas C. nootkatensis and T. mertensiana appeared to rely on local episodes of increased recruitment, which were often separated by centuries, and were probably related to multiple-tree gaps that occurred infrequently. However, such gaps could be considered normal in the long-term history of the stand, and thus these species with their long life spans can persist. Most individuals of all four species grew extremely slowly, with trees typically spending centuries in the understory before reaching the canopy, where they were able to persist for additional centuries. Thus, the key features of this forest are the very slow dynamics dominated by small-scale events, and the slow growth of stress-tolerant trees. PMID:15322898

Parish, Roberta; Antos, Joseph A

2004-12-01

329

Dendrochronologia 22 (2005) 93106 ORIGINAL ARTICLE  

E-print Network

Pinus albicaulis Engelmann (whitebark pine), Abies lasiocarpa [Hooker] Nuttall (subalpine fir), Tsuga reserved. Keywords: Temperature and snowpack reconstruction; Pinus albicaulis; Abies lasiocarpa; Tsuga

Smith, Dan

330

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

331

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

SciTech Connect

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.

Rhodes, T.E.; Davis, R.B. [Univ. of Maine, Orono, ME (United States)

1995-04-01

332

Stem respiratory potential in six softwood and four hardwood tree species in the central cascades of Oregon.  

PubMed

Mature and old growth trees of varying sapwood thickness were compared with regard to stem respiration. An increment core-based, laboratory method under controlled temperature was used to measure tissue-level respiration (termed respiratory potential) of ten different tree species. Bark (dead outer and live inner combined), sapwood, and heartwood thickness measurements were used to predict sapwood volume from stem diameter (including bark) for four of the ten species. These predictions of sapwood volume were used to scale respiratory potential to the main-bole level (excluding all branches). On the core level, species that maintained narrow sapwood (8-16% of bole radius) such as Pseudotusga menziesii, Taxus brevifolia, and Thuja plicata, had sapwood respiratory potentials in the lower bole that were 50% higher (P<0.05) than species with wide sapwood (>16% of bole radius), such as Abies amabilis, Pinus monticola, and Tsuga heterophylla. This pattern was not observed for inner bark respiratory potential, or for sapwood respiratory potential within the crown. On the main-bole level, respiratory potential per unit volume was inversely correlated to the live bole volumetric fraction (inner bark plus sapwood divided by whole bole volume) (Adj. R(2)=0.6). Specifically, tree species with 18-20% of the main bole alive potentially respired 1.3-3 times more per unit live bole volume than species with over 40%, suggesting that the live bole was less metabolically active in tree species that maintained large volumes of sapwood. PMID:12844251

Pruyn, Michele L; Harmon, Mark E; Gartner, B L

2003-09-01

333

Fire and Vegetation History from the Coastal Rain Forest of the Western Oregon Coast Range  

NASA Astrophysics Data System (ADS)

High-resolution charcoal and pollen analyses were used to reconstruct a 4600-yr-long history of fire and vegetation near Taylor Lake in the wettest forests of coastal Oregon. Today, fires in these forests are rare because the season of ignition does not coincide with months of dry fuels. From ca. 4600 to 2700 cal yr B.P. fire episodes occurred at intervals of 140±30 yr while forest vegetation was dominated by disturbance-adapted taxa such as Alnus rubra. From ca. 2700 cal yr B.P. to the present, fire episodes have become less common, occurring at intervals of 240±30 yr, and fire-sensitive forest taxa, such as Tsuga heterophylla and Picea sitchensis, have become more prominent. Fire occurrence during the mid-Holocene was similar to that of the more xeric forests in the eastern Coast Range and suggests that summer drought was widespread. After ca. 2700 cal yr B.P., a decrease in fire episode frequency suggests that cooler conditions and possibly increased summer fog allowed the establishment of present-day Picea sitchensis forests within the watershed. These results provide evidence that fire has been an important disturbance agent in the Coast Range of Oregon, and variations in fire frequency and climate have led to the establishment of present-day forests.

Long, Colin J.; Whitlock, Cathy

334

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

USGS Publications Warehouse

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.

Rambo, T.; Muir, Patricia S.

1998-01-01

335

Abrupt climate change as an important agent of ecological change in the Northeast U.S. throughout the past 15,000 years  

NASA Astrophysics Data System (ADS)

We use a series of tests to evaluate two competing hypotheses about the association of climate and vegetation trends in the northeastern United States over the past 15 kyrs. First, that abrupt climate changes on the scale of centuries had little influence on long-term vegetation trends, and second, that abrupt climate changes interacted with slower climate trends to determine the regional sequence of vegetation phases. Our results support the second. Large dissimilarity between temporally close fossil pollen samples indicates large vegetation changes within 500 years across >4° of latitude at ca 13.25-12.75, 12.0-11.5, 10.5, 8.25, and 5.25 ka. The evidence of vegetation change coincides with independent isotopic and sedimentary indicators of rapid shifts in temperature and moisture balance. In several cases, abrupt changes reversed long-term vegetation trends, such as when spruce ( Picea) and pine ( Pinus) pollen percentages rapidly declined to the north and increased to the south at ca 13.25-12.75 and 8.25 ka respectively. Abrupt events accelerated other long-term trends, such as a regional increase in beech ( Fagus) pollen percentages at 8.5-8.0 ka. The regional hemlock ( Tsuga) decline at ca 5.25 ka is unique among the abrupt events, and may have been induced by high climatic variability (i.e., repeated severe droughts from 5.7 to 2.0 ka); autoregressive ecological and evolutionary processes could have maintained low hemlock abundance until ca 2.0 ka. Delayed increases in chestnut ( Castanea) pollen abundance after 5.8 and 2.5 ka also illustrate the potential for multi-century climate variability to influence species' recruitment as well as mortality. Future climate changes will probably also rapidly initiate persistent vegetation change, particularly by acting as broad, regional-scale disturbances.

Shuman, Bryan N.; Newby, Paige; Donnelly, Jeffrey P.

2009-08-01

336

Dendroclimatic estimates of a drought index for northern Virginia  

USGS Publications Warehouse

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.

Puckett, Larry J.

1981-01-01

337

Recognizing Non-Stationary Climate Response in Tree Growth for Southern Coastal Alaska, USA  

NASA Astrophysics Data System (ADS)

Stationarity in growth response of trees to climate over time is assumed in dendroclimatic studies. Recent studies of Alaskan yellow-cedar (Chamaecyparis nootkatensis (D. Don) Spach) have identified warming-induced early loss of insulating snowpack and frost damage as a mechanism that can lead to decline in tree growth, which for this species is documented over the last century. A similar stress may be put on temperature-sensitive mountain hemlock (Tsuga mertensiana (Bong.) Carrière) trees at low elevations, which in some cases show a decline in tree growth with warming temperatures. One of the challenges of using tree-ring based SAT, SST, PDO and PNA-related reconstructions for southern coastal Alaska has been understanding the response of tree-ring chronologies to the warming temperatures over the past 50 years. Comparisons of tree growth with long meteorological records from Sitka Alaska that extend back to 1830 suggest many mountain hemlock sites at low elevations are showing decreasing ring-widths, at mid elevations most sites show a steady increasing growth tracking warming, and at treeline a release is documented. The recognition of this recent divergence or decoupling of tree-ring and temperature trends allows for divergence-free temperature reconstructions using trees from moderate elevations. These reconstructions now provide a better perspective for comparing recent warming to Medieval warming and a better understanding of forest dynamics as biomes shift in response to the transition from the Little Ice Age to contemporary warming. Reconstructed temperatures are consistent with well-established, entirely independent tree-ring dated ice advances of land-terminating glaciers along the Gulf of Alaska providing an additional check for stationarity in the reconstructed interval.

Wiles, G. C.; Jarvis, S. K.; D'Arrigo, R.; Vargo, L. J.; Appleton, S. N.

2012-12-01

338

Sap flux-upscaled canopy transpiration, stomatal conductance, and water use efficiency in an old growth forest in the Great Lakes region of the United States  

NASA Astrophysics Data System (ADS)

Combining sap flux and eddy covariance measurements provides a means to study plant stomatal conductance and the relationship between transpiration and photosynthesis. We measured sap flux using Granier-type sensors in a northern hardwood-dominated old growth forest in Michigan, upscaled to canopy transpiration, and calculated canopy conductance. We also measured carbon and water fluxes with the eddy covariance method and derived daytime gross primary production (GPP). The diurnal patterns of sap flux and canopy transpiration were mainly controlled by vapor pressure deficit (D) and photosynthetically active radiation (PAR). Daily sums of sap flux and canopy transpiration had exponential relationships to D that saturated at higher D and had linear relationships to PAR. Sugar maple (Acer saccharum) and yellow birch (Betula alleghaniesis) had higher sap flux per unit of sapwood area than eastern hemlock (Tsuga canadensis), while sugar maple and hemlock had higher canopy transpiration per unit of leaf area than yellow birch. Sugar maple dominated canopy transpiration per ground area. Canopy transpiration averaged 1.57 mm d-1, accounting for 65% of total evapotranspiration in the growing season. Canopy conductance was controlled by both D and PAR, but the day-to-day variation in canopy conductance mainly followed a negatively logarithmic relationship with D. By removing the influences of PAR, half-hourly canopy conductance was also negatively logarithmically correlated with D. Water use efficiency (WUE) had a strong exponential relationship with D on a daily basis and approached a minimum of 4.4 mg g-1. WUE provides an alternative to estimate GPP from measurements of sap flux.

Tang, Jianwu; Bolstad, Paul V.; Ewers, Brent E.; Desai, Ankur R.; Davis, Kenneth J.; Carey, Eileen V.

2006-06-01

339

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...

340

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

Microsoft Academic Search

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

Susan N. Little; Janet L. Ohmann

1985-01-01

341

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Board's regulations, including Section 400.13, and further subject to a restriction prohibiting admission of foreign status silicon metal subject to an antidumping or countervailing duty order and to a condition that the company shall submit...

2013-04-09

342

Biochemistry of hemlock (Conium maculatum L.) alkaloids and their acute and chronic toxicity in livestock. A review.  

PubMed

The literature on Conium maculatum biochemistry and toxicology, dispersed in a large number of scientific publications, has been put together in this review. C. maculatum is a weed known almost worldwide by its toxicity to many domestic animals and to human beings. It is an Umbelliferae, characterized by long, hollow stems, reaching up to 2 m height at maturity, producing a large amount of lush foliage during its vegetative growth. Its flowers are white, grouped in umbels formed by numerous umbellules. It produces a large number of seeds that allow the plant to form thick stands in modified soils, sometimes encroaching on cultivated fields, to the extent of impeding the growth of any other vegetation inside the C. maculatum area of growth. Eight piperidinic alkaloids have been identified in this species. Two of them, gamma-coniceine and coniine are generally the most abundant and they account for most of the plant acute and chronic toxicity. These alkaloids are synthesized by the plant from eight acetate units from the metabolic pool, forming a polyketoacid which cyclises through an aminotransferase and forms gamma-coniceine as the parent alkaloid via reduction by a NADPH-dependent reductase. The acute toxicity is observed when animals ingest C. maculatum vegetative and flowering plants and seeds. In a short time the alkaloids produce a neuromuscular blockage conducive to death when the respiratory muscles are affected. The chronic toxicity affects only pregnant animals. When they are poisoned by C. maculatum during the fetuses organ formation period, the offspring is born with malformations, mainly palatoschisis and multiple congenital contractures (MCC; frequently described as arthrogryposis). Acute toxicity, if not lethal, may resolve in the spontaneous recovery of the affected animals provided further exposure to C. maculatum is avoided. It has been observed that poisoned animals tend to return to feed on this plant. Chronic toxicity is irreversible and although MCC can be surgically corrected in some cases, most of the malformed animals are lost. Since no specific antidote is available, prevention is the only way to deal with the production loses caused by this weed. Control with herbicides and grazing with less susceptible animals (such as sheep) have been suggested. C. maculatum alkaloids can be transferred to milk and to fowl muscle tissue through which the former can reach the human food chain. The losses produced by C. maculatum chronic toxicity may be largely underestimated, at least in some regions, because of the difficulty in associate malformations in offspring with the much earlier maternal poisoning. PMID:10340826

López, T A; Cid, M S; Bianchini, M L

1999-06-01

343

Biochemistry of hemlock ( Conium maculatum L.) alkaloids and their acute and chronic toxicity in livestock. A review  

Microsoft Academic Search

The literature on Conium maculatum biochemistry and toxicology, dispersed in a large number of scientific publications, has been put together in this review. C. maculatum is a weed known almost worldwide by its toxicity to many domestic animals and to human beings. It is an Umbelliferae, characterized by long, hollow stems, reaching up to 2 m height at maturity, producing

T. A López; M. S Cid; M. L Bianchini

1999-01-01

344

Five-year growth response of western red cedar, western hemlock, and amabilis fir to chemical and organic fertilizers  

Microsoft Academic Search

The hypothesis that growth responses of conifers to application of organic fertilizers are of longer duration than responses to chemical fertilizers was tested in two trials on northern Vancouver Island. Both trials were in 10-year-old plantations of conifers on a salal-dominated cutover known to have poor N supply. In Trial 1, western red cedar (Thuja plicata Donn ex D. Don),

C. E. Prescott; S. M. Brown

1998-01-01

345

The effects of gap disturbance on nitrogen cycling and retention in late-successional northern hardwood–hemlock forests  

Microsoft Academic Search

Late-successional forests in the upper Great Lakes region are susceptible to nitrogen (N) saturation and subsequent nitrate\\u000a (NO3?) leaching loss. Endemic wind disturbances (i.e., treefall gaps) alter tree uptake and soil N dynamics; and, gaps are particular\\u000a susceptible to NO3? leaching loss. Inorganic N was measured throughout two snow-free periods in throughfall, forest floor leachates, and mineral\\u000a soil leachates in

B. C. Scharenbroch; J. G. Bockheim

2008-01-01

346

Lidar Remote Sensing of the Canopy Structure and Biophysical Properties of Douglas-Fir Western Hemlock Forests  

Microsoft Academic Search

Scanning lidar remote sensing systems have recently become available for use in ecological applications. Unlike conventional microwave and optical sensors, lidar sensors directly measure the distribution of vegetation material along the vertical axis and can be used to provide three-dimensional, or volumetric, characterizations of vegetation structure. Ecological applications of scanning lidar have hitherto used one-dimensional indices to characterize canopy height.

M. A. Lefsky; W. B. Cohen; S. A. Acker; G. G. Parker; T. A. Spies; D. Harding

1999-01-01

347

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

Federal Register 2010, 2011, 2012, 2013, 2014

...has been submitted to the Foreign-Trade Zones Board (the Board) by the Metropolitan...to the provisions of the Foreign-Trade Zones Act, as amended (19 U.S.C...dichlorosilanes (duty rate ranges from duty-free to 5.5%). HSLLC has...

2011-10-12

348

Evidence for continental crustal assimilation in the Hemlock Formation flood basalts of the early Proterozoic Penokean Orogen, Lake Superior region  

SciTech Connect

This paper reports on two a major suites of mafic volcanic and intrusive rocks that are juxtaposed across the Niagara fault zone within the central part of the Penokean Orogen. Neodymium isotopic systematic, geochemical characteristics, and tectonic settings suggest that north of the fault zone rocks possibly were erupted during a major rifting event in the early Proterozoic, but rocks south of the fault zone reflect mixing of an early Proterozoic juvenile basaltic component with a continental-crustal light rare earth element-enriched component.

Beck, J.W.; Murphy (Minnesota Univ., Minneapolis, MN (United States))

1991-01-01

349

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

SciTech Connect

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.

Puckett, L.J.

1982-07-01

350

Role of Nurse Logs in Forest Expansion at Timberline  

NASA Astrophysics Data System (ADS)

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.

Johnson, A. C.; Yeakley, A.

2008-12-01

351

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

SciTech Connect

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.

McCorquodale, S.M. (Pacific Northwest Lab., Richland, WA (United States))

1991-04-01

352

Detecting long-term hydrological patterns at Crater Lake, Oregon  

USGS Publications Warehouse

Tree-ring chronologies for mountain hemlock (Tsuga mertensiana) were used to reconstruct the water level of Crater Lake, a high-elevation lake in the southern Cascade Range of Oregon. Reconstructions indicate that lake level since the late 1980s has been lower than at any point in the last 300 years except the early 1930s to mid 1940s. Lake level was consistently higher during the Little Ice Age than during the late 20th century; during the late 17th century, lake level was up to 9 m higher than recent (1980s and 1990s) low levels, which is consistent with paleoclimalic reconstructions of regional precipitation and atmospheric pressure. Furthermore, instrumental data available for the 20th century suggest that there are strong teleconnections among atmospheric circulation (e.g., Pacific Decadal Oscillation), tree growth, and hydrology in southern Oregon. Crater Lake is sensitive to interannual, interdecadal and intercentenary variation in precipitation and atmospheric circulation, and can be expected to track both short-term and longterm variation in regional climatic patterns that may occur in the future.

Peterson, D.L.; Silsbee, D.G.; Redmond, Kelly T.

1999-01-01

353

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

SciTech Connect

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.

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

354

Parallel climate and vegetation responses to the early Holocene collapse of the Laurentide Ice Sheet  

NASA Astrophysics Data System (ADS)

Parallel changes in lake-level and pollen data show that the rapid decline of the Laurentide Ice Sheet (LIS) between 10,000 and 8000 cal yr BP triggered a step-like change in North American climates: from an ice-sheet-and-insolation-dominated climate to a climate primarily controlled by insolation. Maps of the lake-level data from across eastern North America show a reorganization of climate patterns that the pollen data independently match. Raised lake-levels and expanded populations of moist-tolerant southern pines ( Pinus) document that summer monsoons intensified in the southeastern United States between 9000 and 8000 cal yr BP. Simultaneously, low lake-levels and an eastward expansion of the prairie illustrate an increase in mid-continental aridity. After the Hudson Bay ice dome collapsed around 8200 cal yr BP, lake-levels rose in New England, as populations of mesic plant taxa, such as beech ( Fagus) and hemlock ( Tsuga), replaced those of dry-tolerant northern pines ( Pinus). Available moisture increased there after a related century-scale period of colder-than-previous conditions around 8200 cal yr BP, which is also recorded in the pollen data. The comparison between pollen and lake-level data confirms that vegetations dynamics reflect climatic patterns on the millennial-scale.

Shuman, Bryan; Bartlein, Patrick; Logar, Nathaniel; Newby, Paige; Webb, Thompson

2002-09-01

355

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

USGS Publications Warehouse

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.

Woodward, Andrea

1998-01-01

356

Micronesica 41(2):263274, 2011 Survey of invasive plants on Guam and identification of the 20 most  

E-print Network

hirta, Synedrella nodiflora, Mimosa pudica, Leucaena leucocephala, Pennisetum polystachion, Euphorbia paniculatum, Miscanthus floridulus, Euphorbia heterophylla, Chromolaena odorata, Mikania micrantha, Chamaesyce

Reddy, Gadi VP

357

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

PubMed Central

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 ?15N, 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 ?15N and %N in foliage, and %cover of soil nitrogen indicators differed across the waterfall barrier to salmon at each watershed. ?15N 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 ?15N, %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

Mathewson, DD; Hocking, MD; Reimchen, TE

2003-01-01

358

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

NASA Astrophysics Data System (ADS)

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.

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

2010-05-01

359

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)

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.

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

2007-12-01

360

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

SciTech Connect

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.

Delcourt, H.R. (Univ. of Tennessee, Knoxville); Delcourt, P.A.; Spiker, E.C.

1983-01-01

361

Broadening the ecological context of ungulate-ecosystem interactions: the importance of space, seasonality, and nitrogen.  

PubMed

Spatial heterogeneity of soil resources, particularly nitrogen availability, affects herbaceous-layer cover and diversity in temperate forest ecosystems. Current hypotheses predict that ungulate herbivores influence nitrogen availability at the stand scale, but how ungulates affect nitrogen availability at finer spatial scales that are relevant to the herb layer is less understood. We tested the hypothesis that ungulate exclusion reduces the spatial complexity of nitrogen availability at neighborhood scales (1-26 m) apart from mean stand scale effects. This outcome was expected due to a lack of ungulate nitrogenous waste deposition within exclosures and seasonally variable ungulate habitat use. To test this hypothesis we examined spatial patterning of ammonium and nitrate availability, herb-layer cover and diversity, and under-canopy solar radiation using geostatistical models. Our study sites included six stands of eastern hemlock (Tsuga canadensis) forest: three where white-tailed deer (Odocoileus virginianus) were excluded and three that were accessible to deer. Where deer were present, patch sizes of ammonium availability, cover, and diversity were smaller compared to deer exclosures, whereas mean site-level effects were not significant. Within deer exclosures cover and solar radiation were more similar in patch size than were cover and nitrogen availability. Our results suggest that browsing ungulates affect spatial patterns of herb-layer cover and diversity through the excretion of nitrogenous wastes in small, discrete patches. Ungulate-excreted nitrogen deposition and herbivory were concentrated in the dormant season, allowing herb-layer plants a greater opportunity to benefit from nitrogen additions. Therefore, the impact of ungulates on nitrogen cycling in forest ecosystems varies with spatial scale and the seasonal timing of ungulate impacts. In this way, ungulates may function as a seasonally dependent link between fine-scale and landscape-level ecological processes. PMID:23923495

Murray, Bryan D; Webster, Christopher R; Bump, Joseph K

2013-06-01

362

Evidence for Younger Dryas-age cooling on the North Pacific coast of America  

NASA Astrophysics Data System (ADS)

A review of the palynological evidence from the Olympic Peninsula of Washington State north to the Alaska Panhandle strongly supports the existence of a climatic oscillation similar in timing and effect to the Younger Dryas cooling (11-10 ka BP) of Europe and eastern North America. The evidence includes many late-glacial pollen peaks of mountain hemlock ( Tsuga mertensiana), an indicator of cool and moist climate, reversals from forest to non-arboreal vegetation, and paleoclimate analysis using pollen-climate transfer functions on the Queen Charlotte Islands. Evidence of cooler ocean waters, based on fossil foraminifera in cores from the continental shelf, also supports an interpretation of a Younger Dryas-age climatic reversal. On the other hand, geological evidence of glacier readvances during the Younger Dryas chronozone is weak and poorly dated. Although more and better-constrained (AMS) dates are needed to confirm the timing of the Pacific Northwest cold oscillation, results so far point to maximum cooling and increased moisture between ca. 10.7-10 ka BP, followed by rapid warming in the early Holocene. Additional late-glacial sites need to be investigated in detail to confirm the geographical pattern of vegetation and climate change during this interval, which is best expressed in hypermaritime and maritime climate regions, similar to the Younger Dryas event around the North Atlantic. These results suggest that the search for causal mechanisms to drive the Younger Dryas cooling cannot be limited to events in the North Atlantic region, but should focus on possible hemispheric or global processes.

Mathewes, Rolf W.

363

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

USGS Publications Warehouse

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.

Tamulonis, Kathryn L.; Kappel, William M.

2009-01-01

364

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

PubMed

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

St Clair, Samuel B; Lynch, Jonathan P

2005-01-01

365

Object-oriented modeling and GIS integration in a decision support system for the management of eastern hemlock looper in Newfoundland  

Microsoft Academic Search

Recently available system design tools were used to explore the re-engineering of pest management models and the computer system frameworks used to deliver these models in order to improve model expansion and to apply them to new problems. These models and frameworks were integrated with software tools to form decision support systems (DSS) for operational use by managers in the

J. M. Power; H. Saarenmaa

1995-01-01

366

Windthrow damage 2 years after partial cutting at the Date Creek silvicultural systems study in the Interior Cedar?Hemlock forests of northwestern British Columbia  

Microsoft Academic Search

Partial cutting that removed either 30 or 60% of the volume as single trees or small groups up to 0.5 ha had little effect on wind damage to merchantable trees (?17.5 cm diameter). On average, 6.7 stems per hectare of windthrow occurred across unlogged and logged units, representing approximately 1.9% of the standing trees. Over 2 years, 0.63 m2·hañ1 of

K. Dave Coates

1997-01-01

367

Coastal rainforest connections disclosed through a Late Quaternary vegetation, climate, and fire history investigation from the Mountain Hemlock Zone on southern Vancouver Island, British Colombia, Canada  

Microsoft Academic Search

The post-glacial vegetation and fire history of high-elevation regions on southern Vancouver Island is described using palynological and charcoal records from Porphyry and Walker lakes. A zone consisting mainly of Artemisia, Poaceae, and ferns occurs in the basal clay at Porphyry Lake and may represent a non-arboreal ecosystem in a late-Wisconsin glacial refugium. At both sites, a fire-free Pinus contorta

K. J. Brown; R. J. Hebda

2003-01-01

368

Journal of the Torrey Botanical Society 132(3), 2005, pp. 458470 Changes in a hemlock-dominated forest following woolly  

E-print Network

, and in revised form April 26, 2005. urban shade tree and a major component of de- ciduous wetland forests (Quercus velutina, Q. coccinea, Q. rubra) increased from 28% of canopy basal area in 1982 to 41% in 2002, with greater impor- tance of black oaks on more xeric ledge sites and mixed canopy dominance in mesic ravine

Doyle, Martin

369

A woodchuck mows down an entire row of new cabbage transplants... A porcupine is destroying a hedge of hemlocks...Flyingsquirrelsarekeepingfamilymembersawake,chatteringandracingthroughthewallsallnight.  

E-print Network

with an abundance native wild animals. But sooner or later, most Granite State households practical solutions to everyday questions Toll free Info Line 1-877-398-4769 M-F · 9 AM - 2 PM #12;Bats entrances between May and August to avoid sealing in nursing pups. The US Centers for Disease Control

New Hampshire, University of

370

dynamic processes in cells (a systems approach to biology)  

E-print Network

the mechanical affections of the particles of rhubarb, hemlock, opium and a man ... we should be able to tell beforehand that rhubarb will purge, hemlock kill and opium make a man sleepy" * * John Locke, An Essay

Gunawardena, Jeremy

371

114 2010 USDA Research Forum on Invasive Species GTR-NRS-P-75 INITIAL SURVEY OF PREDACIOUS DIPTERA  

E-print Network

). This family was scarce in our aerial collections. Syrphidae, or hover flies, have many well-known predators of hover flies in nature, we collected surprisingly few from hemlock. Figure 1.--Map showing hemlock

372

Research Disciplines: Ecology ~ Geology ~ Geomorphology ~ Hydrology ~ Pedology ~ Silviculture Systems ~ Wildlife Biology, Ecology, and Management  

E-print Network

Research Disciplines: Ecology ~ Geology ~ Geomorphology ~ Hydrology ~ Pedology ~ Silviculture Systems ~ Wildlife Biology, Ecology, and Management of Western Hemlock Dwarf Mistletoe in Coastal British.W. Negrave. 2007. Biology, Ecology, and Management of Western Hemlock Dwarf Mistletoe in Coastal British

373

18. (MICROFILM ORIGINAL): WISCONSIN STATE HIGHWAY COMMISSION DIAGRAM N673. 'TUBULAR ...  

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

18. (MICROFILM ORIGINAL): WISCONSIN STATE HIGHWAY COMMISSION DIAGRAM N673. 'TUBULAR STEEL PIERS FOR THE HEMLOCK BRIDGE. 8-26-14.' - Hemlock Bridge, Spanning Black River on Warner Drive, Greenwood, Clark County, WI

374

19. (MICROFILM ORIGINAL): WISCONSIN STATE HIGHWAY COMMISSION DIAGRAM N674. "APPROACH ...  

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

19. (MICROFILM ORIGINAL): WISCONSIN STATE HIGHWAY COMMISSION DIAGRAM N674. "APPROACH PLANS FOR THE HEMLOCK BRIDGE. 8-29-14" - Hemlock Bridge, Spanning Black River on Warner Drive, Greenwood, Clark County, WI

375

Some improvements will be almost immediate...  

E-print Network

Some improvements will be almost immediate... Hemlock Dam before removal After removal #12;Some-makers so that realistic timeframes can be established Trout Creek above former site of Hemlock Dam #12;PIT

376

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

NASA Astrophysics Data System (ADS)

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.

Vose, J.; Ford, C. R.

2011-12-01

377

Molecular Structure of pseudo-Conhydrine  

NSDL National Science Digital Library

Hemlock is an herb with a purple-spotted stem and leaves resembling parsley. The leaves are nauseating to eat, and ingestion may be fatal. The chemical poisons in hemlock are alkaloids like coniine and they affect the nervous system. Hemlock is the poison that Socrates was offered to cause his death.

2002-08-27

378

Ford Forestry Center and Research Forest Historical Stand Cover (c. 1956)  

E-print Network

Paper Birch/Aspen Aspen/Paper Birch Paper Birch/Aspen/Oak Jack Pine Jack Pine/Aspen Plantation Red Pine Red Pine/Paper Birch Red Pine/Upland Spruce-Fir White Pine Pine/Oak Northern Hardwoods Northern Hardwoods/Hemlock Hemlock Hemlock/Cedar Cedar and Mixed Conifers Swamp or Lowland Hardwoods Lowland

379

Environmental change controls postglacial forest dynamics through interspecific differences in life-history traits.  

PubMed

A key goal of functional ecology is identifying relationships between species traits and environmental conditions. Here, the nature and significance of these relationships to community composition on long ecological timescales is investigated using paleoecological and paleoenvironmental data from coastal British Columbia, Canada. RLQ and fourth-corner analyses, two three-table statistical techniques, are used to link traits of the region's dominant woody plants to environmental conditions over the last 15 000 calendar years (cal yr) through a fossil pollen record derived from lake sediments. Both RLQ and fourth-corner analyses revealed highly significant correlations between plant traits and temporal changes in environmental conditions. Axis 1 of the RLQ explained 92% of the total covariance between plant species traits and paleoenvironmental variables and was correlated most strongly with temperature and relative growth rate. In general, climate change during the cold period following deglaciation favored species such as Alnus sinuata and Pinus contorta that exhibit a "fast" life-history strategy (e.g., high relative growth rate, short life span, low shade tolerance), whereas the relative climatic stability of the last 8000 cal yr favored species such as Tsuga heterophylla that exhibit a "slow" life-history strategy (e.g., low relative growth rate, long life span, high shade tolerance). Fourth-corner analyses revealed significant correlations between all paleoenvironmental variables (i.e., temperature, precipitation, summer insolation, vegetation density) and most plant traits (relative growth rate, minimum seed-bearing age, seed mass, height, life span, and shade, drought, and waterlogging tolerances). The strongest correlation was between paleotemperature and height, reflecting the positive effect of temperature on plant growth and development and the overarching competitive advantage that height confers. This research demonstrates that environmental conditions interact significantly with life-history and stress tolerance traits over long ecological timescales to determine forest composition. Climate is the ultimate control on postglacial forest composition and species abundances, but long-term community assembly is also constrained through interspecific differences in plant traits. PMID:19739377

Lacourse, Terri

2009-08-01

380

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

NASA Astrophysics Data System (ADS)

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.

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

2003-04-01

381

ORIGINAL PAPER Influence of climate and disturbance on the growth  

E-print Network

. Keywords Tsuga canadensis Á Dendrochronology Á Ecological amplitude Á Climate Á Biogeography Introduction #12;1989). This principle in dendrochronology is based on the assumption that an environmental

Hart, Justin

382

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

383

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)

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 ?13C in dominant trees and GPP and/or NEE measured by the Harvard Forest flux tower (1992-2010). We have analyzed the ?13C 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. ?13C values, corrected for the declining trend of atmospheric ?13C, show a decreasing trend from 1992 to 2010 and therefore a significant increase in discrimination (?). The intra-cellular CO2 (Ci) calculated from ? 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 ? 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 ?13C 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.

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

2012-12-01

384

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

NASA Astrophysics Data System (ADS)

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.

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

2005-12-01

385

USDA Forest Service Gen. Tech. Rep. PSW-GTR-193. 2004. 69 Fire and Landscapes: Patterns and Processes1  

E-print Network

and temperature, increasing during warm periods dominated by oaks (Quercus spp.) and sagebrush (Artemisia tridentata) and decreasing during cool periods dominated by subalpine species, such as mountain hemlock

Standiford, Richard B.

386

JOURNAL OF ABSTRACTS 2008 Journal of Abstracts  

E-print Network

Invasiveinsectssuchasthegypsymoth(Lymantriadispar), hemlock woollyadelgid(HWA)(Adelgestsugae Annand), and emerald ash borer for the Agricultural Sciences 3 Biological Control Methods for Pennsylvania Invasive Insects elizabeth Argall Tamaqua

Kaye, Jason P.

387

Wet to Wet-Mesic Prairies III.C. Wet to Wet-Mesic Prairies  

E-print Network

),big bluestem (Andropogon gerardii), hummock sedge (Carex stricta), flattened spike-rush (Eleocharis compressa),water hemlock (Cicuta maculata), mountain mint (Pycnanthemum virginianum), Dudley's rush (Juncus dudleyi

US Army Corps of Engineers

388

Inocybe hirsuta var. maxima  

NSDL National Science Digital Library

Inocybe hirsuta var. maxima A. H. Smith (SAT 01-279-08) photographed in the Hoh River Valley in Olympic National Park, Washington, USA. This variety is common in Washington under western hemlock and is also known from eastern North America under eastern hemlock.

Steve Trudell

2004-03-09

389

The Relative Abundance of the Juvenile Phase of the Eastern Red-Spotted Newt at Harvard Forest Prior to the  

E-print Network

) in Eastern Hemlock-dominated stands (n = 5) and mixed deciduous stands (n = 5) at Harvard Forest in Petersham et al. 2012). At Harvard Forest, Eastern Hemlock will likely be replaced by mixed deciduous species117 The Relative Abundance of the Juvenile Phase of the Eastern Red-Spotted Newt at Harvard Forest

Wolfe, Patrick J.

390

(htxwidth,infeet) OherKeyPests  

E-print Network

include the Asian longhorned beetle (ALB), emerald ash borer (EAB), hemlock woolly adelgid (HWA and rates their susceptibility to attack by the Asian Longhorned Beetle, Emerald Ash Borer, Hemlock Woolly of ash (Fraxinus spp.) trees. Since its initial detection in Michigan in 2002, it has spread across

New Hampshire, University of

391

The ALB isn't currently known to be in New Hampshire, but it has been detected as close by as Worcester, MA, and in the  

E-print Network

), emerald ash borer (EAB), hemlock woolly adelgid (HWA), and elongate hemlock scale (EHS). All four insects, like the ALB and EAB, and manage those that are, including the HWA and EHS. EMERALD ASH BORERHEMLOCK of ash (Fraxinus spp.) trees. Since its initial detection in Michigan in 2002, it has spread across

New Hampshire, University of

392

Molecular Ecology (2006) 15, 24092419 doi: 10.1111/j.1365-294X.2006.02957.x 2006 The Authors  

E-print Network

arboreal components of the mesic temperate forest, western red cedar (Thuja plicata) and western hemlock behaviour, linear distribution, and dependence on cedar­hemlock forests. Keywords: disjunct population), and as the ice retreated trees rapidly colonized deglaciated areas (Warner et al. 1982; Barnosky et al. 1987

Winker, Kevin

393

Welcome everyone, thank you for coming. My name is ___. I'm a volunteer with Speaking for Wildlife. Speaking for Wildlife is a program by the University of New Hampshire Cooperative Extension that brings  

E-print Network

and forests, two of which are present in the state: emerald ash borer (pictured at the top) and hemlock yourselves. Emerald ash borer and hemlock woolly adelgid are already here in New Hampshire, and Asian being impacted. For example, the emerald ash borer is native to northern China, North Korea, South

New Hampshire, University of

394

Mapping Forest Change Walk  

NSDL National Science Digital Library

The representation depicts a virtual walk through a Virginia forest to examine the impact of a non-native, invasive insect, the hemlock woolly adelgid, on a population of eastern hemlocks. Field research is conducted using the same scientific methodologies and tools that Smithsonian scientists use to monitor forest biodiversity, including scatter graph comparisons and field observations.

395

Cytology of Leidyana canadensis (Apicomplexa: Eugregarinida) in Lambdina fiscellaria fiscellaria Larvae (Lepidoptera: Geometridae)  

Microsoft Academic Search

The eugregarine Leidyana canadensis infects the larval gut of the eastern hemlock looper, Lambdina fiscellaria fiscellaria. Guts of infected larvae were chemically fixed, embedded in epoxy resin, and sectioned for light and electron microscopy to describe the cytology of L. canadensis and its pathology in the larval host. Oocysts of L. canadensis are ingested by larval hemlock looper. Trophozoites emerge

C. J Lucarotti

2000-01-01

396

Ecology, 81(1), 2000, pp. 110126 2000 by the Ecological Society of America  

E-print Network

110 Ecology, 81(1), 2000, pp. 110­126 2000 by the Ecological Society of America DYNAMICS IN LATE-SUCCESSIONAL, Bennington, Vermont 05201 USA Abstract. Permanent plots in old-growth hemlock­northern hardwood forests). From 1962 to 1994 hemlock increased in basal area and dominance in most plots. Sugar maple showed

Woods, Kerry

397

Long-term change and spatial pattern in a late-successional hemlocknorthern hardwood forest  

E-print Network

Long-term change and spatial pattern in a late- successional hemlock±northern hardwood forest KERRY for six decades on a grid of 140 permanent plots in old-growth mesic (hemlock-northern hardwood) forests changed overall. Dynamics appear to be successional in nature, even though there has been no major

Woods, Kerry

398

2011 ISRP Retrospective Presented by  

E-print Network

improvements will be almost immediate... Hemlock Dam before removal After removal #12;Some will take decades projects. #12;Lamprey Few results to date. Critical questions to address: ·Is dam passage (mainstem and that realistic timeframes can be established Trout Creek above former site of Hemlock Dam #12;PIT

399

Virtual Field Trip: Temperate Rain Forest Douglas Fir and Western  

E-print Network

Virtual Field Trip: Temperate Rain Forest Douglas Fir and Western Hemlock forest, Roslyn, Wa. #12;Virtual Field Trip: Temperate Rain Forest Douglas Fir and Western Hemlock forest, Roslyn, Wa. Topics Knysna Forest Biome near Nature's Valley, in the Tsitsikamma, South Africa #12;Climate Precipitation (avg

Hansen, Andrew J.

400

The taxonomic status of physalis lanceolata (Solanaceae) in the Carolina Sandhills  

Microsoft Academic Search

In the most recent monograph of the genus in North America,Physalis lanceolata was considered to be a hybrid betweenP. heterophylla andP. virginiana. Comparative morphological and Chromatographic studies indicate, however, thatP. lanceolata is not intermediate between its supposed parents. This evidence plus its high pollen viability and seed set indicate that\\u000a the species is not a hybrid. Natural hybrids betweenP. heterophylla

W. Frederick Hinton

1970-01-01

401

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

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

402

Paleofire reconstruction for high-elevation forests in the Sierra Nevada, California, with implications for wildfire synchrony and climate variability in the late Holocene  

E-print Network

-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

Anderson, R. Scott

403

Differential Tree Colonization of Old Fields in a Temperate Rain Forest  

E-print Network

fields have been invaded by Picea sitchensis, one of three dominant forest species (with Alnus rubra vegetation. In experiments with transplanted seedlings, cervid herbivory suppressed growth of Tsuga and Alnus

del Moral, Roger

404

ISSUE SEVENTEEN MICHAELMASTERM 2000 The newsletter of the  

E-print Network

, Corylus 2, Fraxinus 4, Pinus 8, Quercus 3, Tsuga 1 Shrubs: Salix 8 Herbs: Chenopodiaceae 1, Plantago lanceolata 1, Poaceae 13, Rosaceae 2, unidentified 4 J.Donner #12;Diary Quaternary Discussion Group

de Gispert, Adrià

405

Root phenology at Harvard Forest and beyond  

NASA Astrophysics Data System (ADS)

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.

Abramoff, R. Z.; Finzi, A.

2013-12-01

406

Current Land UseCurrent Land Use Park Boundary  

E-print Network

in America. This 550-acre forest on the slopes of Mount Tom in southern Vermont is one of the oldest planned Aspen Hardwoods Black Locust Ironwood Beech Hemlock White Pine Evergreens Red Pine N. Spruce S. Pine

Morrissey, Leslie A.

407

Physical Geography, 2003, 24, 6, pp. 488501. Copyright 2003 by V. H. Winston & Son, Inc. All rights reserved.  

E-print Network

a topographic relative moisture index integrating the effects of slope gradient, aspect, hillslope shape index and landform index that quan- tify landform shape and protection, to develop a field: ecosystem classification, terrain shape index, landform index, eastern hemlock.] INTRODUCTION Southern

Abella, Scott R.

408

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

409

The Lichenologist 36(3&4): 235247 (2004) 2004 The British Lichen Society DOI: 10.1017/S0024282904014227 Printed in the United Kingdom  

E-print Network

of organisms that has received considerable attention in recent years, especially in the US Pacific Northwest, forest management, Fraser River valley, inland rainforest, interior cedar-hemlock forest, lichen

Coxson, Darwyn

2004-01-01

410

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

Federal Register 2010, 2011, 2012, 2013, 2014

...No Significant Impact for a Biological Control Agent for Hemlock Woolly Adelgid...United States for use as a biological control agent to reduce the severity...the proposed release of this biological control agent into the...

2011-07-19

411

ADDITIONS, ERRATA, EMENDATA, EXCUSES 16 Mar. 2008  

E-print Network

and under the species (right column, first paragraph), the C. virosa should be Conium maculatum. Page 215 was altered. Page 210 ­ Under Cicuta, Old World hemlock was Conium virosa. Both in the genus etymology

Sanderson, Mike

412

3 CFR 8947 - Proclamation 8947 of March 25, 2013. Establishment of the San Juan Islands National Monument  

Code of Federal Regulations, 2014 CFR

...woodlands, some of which are several hundred years old, include a majestic assemblage of trees, such as Douglas fir, red cedar, western hemlock, Oregon maple, Garry oak, and Pacific madrone. The fire-dependent grasslands, which are...

2014-01-01

413

of Virginia their Uses  

E-print Network

) ___ Blue spruce (specimen) ___ Norway spruce (specimen) ___ Red spruce (lumber, pulpwood) ___ Eastern hemlock (lumber, pulp, specimen) Cypress or Cedar Family ___ Baldcypress (decay-resistant wood products, storage chests) ___ Deodar cedar (specimen) Magnolia Family ___ Cucumbertree (cabinets, shade) ___ Saucer

Liskiewicz, Maciej

414

78 FR 18789 - Establishment of the San Juan Islands National Monument  

Federal Register 2010, 2011, 2012, 2013, 2014

...woodlands, some of which are several hundred years old, include a majestic assemblage of trees, such as Douglas fir, red cedar, western hemlock, Oregon maple, Garry oak, and Pacific madrone. The fire- [[Page 18790

2013-03-28

415

Ecological Setting of the Wind River Old-growth Forest  

E-print Network

(224 trees ha)1 ), Pa- cific yew (86 trees ha)1 ), western red cedar7 (30 trees ha)1 ), and Pacific-intolerant species, to western hemlock, western red cedar, Pacific yew, and Pacific silver fir, all shade

Franklin, Jerry

416

Long-Term Trends in Ecological Systems: Appendix 1: Site Descriptions  

E-print Network

) and western red cedar (THPL). The heartwood of the two latter species is decay resistant (Mark Harmon silver fir (ABAM) and western hemlock (TSHE) compared with Douglas-fir (PSME) and western red cedar (THPL

417

Secular climatic patterns of the North Central Great Plains and the continental U.S.  

E-print Network

Napoleon, ND Bethlehem, NH Belvidere, NJ Charlottesburg, NJ Flemington, NJ Fort Bayard, NM Angelica, NY Hemlock, NY Lowville, NY Mohonk Lake, NY Philo, OH Millport, OH Kingfisher, OK Hood River, OR Blackville, SC Kingstree, SC Summerville...

Praner, Karen Jean

1985-01-01

418

Some statistical associations between Northern Hemisphere sea level pressure patterns and temperatures at selected U.S. climate stations  

E-print Network

Hartington, NE Hay Springs, NE Imperial, NE Kimball, NE Loup City, NE Madison, NE Minden, NE North Loup, NE St. Paul, NE Wakefiteld, NE Bethlehem, NH Belvidere, NJ Charlottesburg, JN Flemington, JN Angelica, NY Hemlock, NY Lowville, NY Mohonk...

Bryan, Janine Marie

1988-01-01

419

Determining the nutritional requirements for optimizing flowering of the nobile dendrobium as a potted orchid  

E-print Network

, the production requirements for Dendrobium nobile remain largely undocumented in the recent scientific literature. Dendrobium nobile plants grown in sphagnum moss (Sphagnum magellanicum Brid.) or hemlock (Conium maculatum L.) bark were given 10 different...

Bichsel, Rebecca Gayle

2009-05-15

420

17. (MICROFILM ORIGINAL): WISCONSIN STATE HIGHWAY COMMISSION DIAGRAM M374. 'STEEL ...  

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

17. (MICROFILM ORIGINAL): WISCONSIN STATE HIGHWAY COMMISSION DIAGRAM M374. 'STEEL HIGHWAY BRIDGE WITH WOOD BLOCK FLOOR. 8-26-14.' - Hemlock Bridge, Spanning Black River on Warner Drive, Greenwood, Clark County, WI

421

Clear and Present Danger: Invasive Species Threats toInvasive Species Threats to  

E-print Network

disease Chesnut Blight Invasive/ Exotic Species Dutch elm disease, Chesnut Blight ­ Hemlock woolly adelgidEcosystem Function altering: · Nutrient cycling · Fire regimes · Hydrology #12;11/10/2010 4 Invasive Species Impacts

Gray, Matthew

422

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

Code of Federal Regulations, 2012 CFR

...Proclamation of April 28, 1916 (39 Stat. 1777), as the waters within three thousand feet from the shore lines at mean low tide of Annette Island, Ham Island, Walker Island, Lewis Island, Spire Island, Hemlock Island, and adjacent rocks and...

2012-04-01

423

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

Code of Federal Regulations, 2010 CFR

...Proclamation of April 28, 1916 (39 Stat. 1777), as the waters within three thousand feet from the shore lines at mean low tide of Annette Island, Ham Island, Walker Island, Lewis Island, Spire Island, Hemlock Island, and adjacent rocks and...

2010-04-01

424

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

Code of Federal Regulations, 2013 CFR

...Proclamation of April 28, 1916 (39 Stat. 1777), as the waters within three thousand feet from the shore lines at mean low tide of Annette Island, Ham Island, Walker Island, Lewis Island, Spire Island, Hemlock Island, and adjacent rocks and...

2013-04-01

425

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

Code of Federal Regulations, 2011 CFR

...Proclamation of April 28, 1916 (39 Stat. 1777), as the waters within three thousand feet from the shore lines at mean low tide of Annette Island, Ham Island, Walker Island, Lewis Island, Spire Island, Hemlock Island, and adjacent rocks and...

2011-04-01

426

Direct and indirect effects of alien insect herbivores on ecological processes and interactions in forests of eastern North America  

Microsoft Academic Search

Alien invasive insects such as gypsy moth, hemlock woolly adelgid, and emerald ash borer continue to disturb the mixed deciduous\\u000a and hemlock forests of eastern North America by causing wide-scale defoliation, decline and\\/or mortality of their hosts. Some\\u000a of the most devastating species are spreading in “defense free space”, causing extensive mortality of hosts that are inherently\\u000a susceptible, perhaps due

Kamal J. K. Gandhi; Daniel A. Herms

2010-01-01

427

Characterization of Nuclear Polyhedrosis Viruses from Three Subspecies of Lambdina fiscellaria  

Microsoft Academic Search

The eastern hemlock looper (EHL),Lambdina fiscellaria fiscellaria,the western hemlock looper (WHL),L. fiscellaria lugubrosa,and the western oak looper (WOL),L. fiscellaria somniaria,are closely related insects that are pests in Canadian forests. We have used restriction endonuclease (REN) and Southern blot analyses to characterize DNA of nuclear polyhedrosis viruses (NPVs) isolated from each of the three subspecies ofL. fiscellaria.REN analysis of EHL-NPV, WHL-NPV,

David B. Levin; Ann Marie Laitinen; Tom Clarke; Christopher J. Lucarotti; Benoit Morin; Imre S. Otvos

1997-01-01

428

Climate Changes Inferred from Pollen Record of Recent 3000 years in Sonluo Lake, Northeastern Taiwan  

NASA Astrophysics Data System (ADS)

Palynological studies can detect the impact of rapid climate changes on terrestrial ecosystems, since vegetation variation in response to climate fluctuation can occur on the order of decades. In this study, we provide a new pollen record from Sonluo Lake and intend to discover the relationship between winter monsoon and climate conditions of northeastern Taiwan during the recent 3000 years. Sonluo Lake, at an elevation of 1300 m AMSL, is an isolated basin located in Shueshan Range, northeastern Taiwan. Annual precipitation is approximately 4,400 mm, and almost occurs evenly through one year. Vegetation surrounding the basin is of the Machilus-Castanopsis vegetation type and lower Quercus vegetation type. Four climatic phases are determined with the aid of palynological studies. During the interval 3000 to 2200 yr BP (Zone IV), abundant pollens of Tsuga and fern spores indicate that the climate conditions were cool and wet than present. Subsequently, the warm climate conditions prevailed between 2200 and 1500 yr BP (Zone III) as suggested by the decline of Tsuga. From 1500 to 700 yr BP (Zone II), the lowest percentage of Tsuga and fern spores indicates a warmest and driest period. Following that, the basin experienced again cool and wet climate conditions since 700 yr BP, evidenced by the return of Tsuga and fern spore. The last climatic phases can be corresponded to the Little Ice Age. The high correlation(R=0.73)between pollen of Tsuga and fern spores indicates that winter monsoon dominant condition in this region.

Wu, Meng-Huan; Liew, Ping-Mei; Lee, Sep; Hsieh, Meng-Long; Huang, Sue-Yue

2010-05-01

429

Phytochemical constituents of some Nigerian medicinal plants  

Microsoft Academic Search

Alkaloids, tannins, saponins, steroid, terpenoid, flavonoids, phlobatannin and cardic glycoside distribution in ten medicinal plants belonging to different families were assessed and compared. The medicinal plants investigated were Cleome nutidosperma, Emilia coccinea, Euphorbia heterophylla, Physalis angulata, Richardia bransitensis, Scopania dulcis, Sida acuta, Spigelia anthelmia, Stachytarpheta cayennensis and Tridax procumbens. All the plants were found to contain alkaloids, tannins and flavonoids

H. O. Edeoga; D. E. Okwu; B. O Mbaebie

430

Structure and dynamics of a tropical dry forest in Ghana  

Microsoft Academic Search

Forest under low rainfall (averaging 745 mm yr-1) on the Shai Hills in S.E. Ghana has redeveloped following cessation of farming in the 1890s. Forest stature is low, with a canopy at about 11 m, principally of three species, Diospyros abyssinica, D. mespiliformis and Millettia thonningii. Drypetes parvifolia and Vepris heterophylla are common understorey trees. Twelve species of woody liane

M. D. Swaine; Diana Lieberman; J. B. Hall

1990-01-01

431

Relations of the western Balkan endemic Campanula L. (Campanulaceae) lineages based on comparative floral morphometry  

Microsoft Academic Search

In the north-eastern quadrant of the Mediterranean Region many endemic Campanula (Campanulaceae) taxa and lineages arose, of which the Isophylla group and the Rotundifolia complex (sect. Heterophylla), essentially separated on the basis of their leaf shapes, and some of the endemic western Balkan, Dinaric lineages (i.e. ‘isophylloid’ aggregates Waldsteiniana and Pyramidalis) are members. The aim of this study is to

S. Kova?i?; T. Nikoli?

2006-01-01

432

Toxic effects of some plants in the genus Euphorbia on haematological and biochemical parameters of rats  

Microsoft Academic Search

ADEDAPO, A. A., M. O. ABATAN, O. O. OLORUNSOGO: Toxic effects of some plants in the genus Euphorbia on haematological and biochemical parameters of rats. Vet. arhiv 74, 53-62, 2004. ABSTRACT The toxic effects of 5 suspected poisonous plants of the genus Euphorbia (Euphorbia balsamifera Aiton, E. heterophylla L., E. hirta L., E. hyssopifolia L., and E. lateriflora Schum and

Adeolu A. Adedapo; Matthew O. Abatan; Olufunso O. Olorunsogo

2004-01-01

433

Preliminary Phytochemical Analysis and Antimicrobial Activity of Some Weeds collected from Marathwada Region  

Microsoft Academic Search

The aqueous and ethanolic extracts of selected weeds such as Portulaca oleracea L. (Portulaceae), Cardiospermum helicacabum L. (Sapindaceae), Euphorbia hirta L. (Euphorbiaceae), Crotalaria retusa L. (Fabaceae) and Euphorbia heterophylla L. (Euphorbiaceae) were screened for phytochemical analysis and antimicrobial activity. The antimicrobial activities were tested against two gram-positive bacteria (Bacillus subtilis, Staphylococus aureus), one gram-negative bacterium (Pseudomonas aeruginosa) and a mould

Dhole JA; Dhole NA; Lone KD; Bodke SS; Rajarshi Shahu

2011-01-01

434

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

PubMed

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

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

2014-01-01

435

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

PubMed Central

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

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

2014-01-01

436

Ecology, 95(8), 2014, pp. 20472054 2014 by the Ecological Society of America  

E-print Network

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 or temporal interval. With demographic rates of annual ingrowth and mortality averaging ,1% to 3% in old

Chen, Jiquan

437

Climatic change causes abrupt changes in forest composition, inferred from a high-resolution pollen record, southwestern Quebec, Canada  

NASA Astrophysics Data System (ADS)

A pollen profile from a lake with varved sediments sampled at continuous 10-year intervals and spanning the past 1000 years was analyzed to understand the effects of climate change and anthropogenic activity on forests in southwestern Quebec. Pollen assemblages were dominated by arboreal taxa, primarily Pinus, Tsuga, Betula and Fagus. Between 990 and 1560 AD, pollen accumulation rates and percentages of hardwoods (Betula, Fagus, Acer, Ulmus, Tilia) and Tsuga were relatively high. At 1560 AD, PARs of many hardwood taxa (Fagus, Acer, Betula, Fraxinus, Ulmus) and Tsuga abruptly decreased, some remaining low for the remainder of the record (Tsuga, Fagus, Acer), but others increasing after 50 years (Betula, Fraxinus). An increase in non-arboreal pollen between 1810 and 2010 AD was caused by European settlement of the area. The transition in the pollen assemblages beginning at 1560 AD and a climate reconstruction based on these data shows an abrupt climate cooling had a significant impact on the pollen accumulation rates of the region within a couple of decades. A synthesis of this record with other high-resolution and well-dated pollen data from the conifer-hardwood forest of eastern North America shows consistent results across the whole area, indicating that very-high resolution pollen data can provide insight into multi-decadal climate variability and its impact on forest vegetation.

Paquette, Nathalie; Gajewski, Konrad

2013-09-01

438

Inhibition of Methane Consumption in Forest Soils by Monoterpenes  

Microsoft Academic Search

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 (bulk and intact cores) and slurry conditions. Most of

J. A. Amaral; R. Knowles

1998-01-01

439

Scale-dependent drivers of ungulate patch use along a temporal and spatial gradient of snow  

E-print Network

-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) selection of eastern hem- lock (Tsuga canadensis (L model, habitat selection, white-tailed deer (Odocoileus virginianus), Upper Peninsula of Michigan par le cerf de Virginie (Odocoileus virginianus (Zimmer- mann, 1780)) de parcelles de pruches du

440

Rocky Great Mountains Southwest Plains  

E-print Network

aspen. Keywords: Snags, cavities, wildlife, Pinus ponderosa, Pseudo- tsuga menziesii, Populus) and ponderosa pine (Pinus ponderosa), and on higher ridges limber pine (Pinus ffexilis)and ponderosa pine forest of mature ponderosa pine-Douglas- fir contained 6.5 snags and spike-top trees per hectare

441

Resistance of fast-and slow-growing subalpine fir to pheromone-induced attack by western balsam bark beetle (Coleoptera  

E-print Network

and vigour of its subalpine fir host. Keywords Abies lasiocarpa, bark beetles Dryocoetes confusus, growth, including trees in the genera Larix, Pseudotsuga, Picea and Pinus; however, trees in the genera Abies, Tsuga). Conifers, such as subalpine fir Abies lasioicarpa (Hook.) Nutt., that lack extensive vertical resin canals

Lindgren, Staffan

442

The Holocene 11,2 (2001) pp. 177188 Postglacial history of subalpine forests,  

E-print Network

and Moose Lake (1508 m) in the drier Abies lasiocarpa zone. The interpret- ation of fossil pollen). In contrast to Martins Lake, Abies lasiocarpa forest quickly established at Moose Lake in the early Holocene of Chamaecyparis nootkatensis, Tsuga mertensiana and Pinus, though Abies lasiocarpa remained dominant. For- est

Gavin, Daniel G.

2001-01-01

443

A record of Lateglacial and Holocene vegetation and climate change from Woods Lake, Seymour Inlet, coastal British Columbia, Canada  

Microsoft Academic Search

The Lateglacial and Holocene vegetation and environmental history recorded in a small coastal lake in the Seymour Inlet area, British Columbia, is described. Pinus-dominated vegetation and a cool and moist climate prevailed in the early phase of the Lateglacial. Later stages of the Lateglacial were characterised by a mixed coniferous forest with Tsuga species, Picea and Abies and slightly warmer

Susann Stolze; Helen M. Roe; R. Timothy Patterson; Thomas Monecke

2007-01-01

444

Dendroglaciological evidence for Holocene glacial advances in the Todd Icefield area, northern British Columbia Coast Mountains  

Microsoft Academic Search

Accelerated glacial recession and downwasting in Pacific North America is exposing land surfaces and fea- tures buried by glacial advances that, in many locations, predate the recent Little Ice Age (LIA). Dendrochronologic analyses of increment core samples from living trees (Abies lasiocarpa, Tsuga mertensiana) and samples of subfossil wood collected in the Todd Icefield area, Boundary Ranges, British Columbia Coast

Scott I. Jackson; Sarah C. Laxton; Dan J. Smith

2008-01-01

445

Craterellus fallax, a Black Trumpet mushroom from eastern North America with a broad host range  

E-print Network

SHORT NOTE Craterellus fallax, a Black Trumpet mushroom from eastern North America with a broad of Tsuga, Quercus, and possibly Castanea supports a broad host range in North America for the ECM symbiont complex are recorded from Europe, North America, Central America, South America, and Asia (Pilz et al

Matheny, P. Brandon

446

Molecular Phylogeny of Pinaceae and Pinus  

Microsoft Academic Search

Molecular phylogenetic reconstructions of Pinaceae based on immunological approaches plus nuclear and organellar DNA sequences consistently resolve the generic pairs Larix - Pseudotsuga and Abies - Keteleeria. In most analyses Pseudolarix and Tsuga (including Nothotsuga) form a clade that is sister to the Abies - Keteleeria clade, and Cathaya, Picea, and Pinus make up an unresolved trichotomy. The position of

Aaron Liston; David S. Gernandt; Thomas F. Vining; Christopher S. Campbell; Daniel Piñero

447

USDA Forest Service Proceedings RMRS-P-63. 2011. 235 ExtendedAbstract  

E-print Network

's (Pinus albicaulis) notable ecological values, combined with its precarious state, underscore the need activity from mature western white pine (Pinus mon- ticola), or whitebark pine of any age, appear absent (Tsuga mertensiana) and lodgepole pine (Pinus contorta var. murrayana) are common co-dominants. Shasta

448

[Child poisoning after ingestion of a wild apiaceae: a case report].  

PubMed

Apiaceae family (formerly Umbelliferae) contains several highly toxic species, including Poison Hemlock (Conium maculatum), Water Hemlock (Cicuta virosa) and Hemlock Water Dropwort (Oenanthe crocata) which are the three main poisonous Apiaceae species growing in France. Thinking he was identifying wild carrots, an 11-year-old boy without previous history ingested the root from a wild Apiaceae. One hour later, he was confused, had drowsiness, headache as well as abdominal pain, vomiting and diarrhoea. Upon hospital admission, myosis, ophtalmoplegia and a moderate rhabdomyolysis were noted. The patient recovered after 24 h of symptomatic treatments. In this case, the description of the ingested plant allowed to identify the Apiaceae family but not the species involved. The geographical location (Southern France in a humid area), the clinical features and the aspect of the ingested root, with an orange secretion led to implicate Oenanthe crocata as the origin of this unusual poisoning. PMID:18206356

Durand, M-F; Pommier, P; Chazalette, A; de Haro, L

2008-02-01

449

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

SciTech Connect

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 +

Frisbie, M.P.; Wyman, R.L. (Eastern Kentucky Univ., Richmond, KY (United States))

1994-06-01

450

Seed abundance versus substrate limitation of seedling recruitment in northern temperate forests of British Columbia  

Microsoft Academic Search

We examine the influence of (i) the spatial distribution and abundance of parent trees (as seed sources) and (ii) the abundance and favourability of seedbed substrates, on seedling recruitment for the major tree species in north - western interior cedar-hemlock forests of British Columbia, under four levels of canopy openness (full canopy, partial canopy, large gap, and clearcut). Substrate distribution

Philip T. LePage; Charles D. Canham; K. Dave Coates; Paula Bartemucci

2000-01-01

451

Soil drainage and vegetation controls of nitrogen transformation rates in forest soils, southern Quebec  

E-print Network

Soil drainage and vegetation controls of nitrogen transformation rates in forest soils, southern and tree species on nitrogen (N) mineralization and nitrification rates in two forest catenas in southern. Potential N transformation rates in soils under American beech, sugar maple, and eastern hemlock trees were

Moore, Tim

452

76 FR 61599 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Marbled Murrelet  

Federal Register 2010, 2011, 2012, 2013, 2014

...areas not in the western hemlock/ tanoak vegetation on the Grants Pass and Glendale Resource...tanoak and mixed-conifer/ evergreen vegetation zones. These areas were not considered...efforts were minimal in many areas, coverage of areas surveyed was...

2011-10-05

453

Black Birch (Betula lenta L.) Better known as sweet birch in southern Appalachia, its inner and outer bark contains an essential oil that has the flavor and scent of wintergreen. In the past, the sap was used to make a beer and a tea made from the bark wa  

E-print Network

The medicinal uses of these plants, as used by the early settlers in the region, have been identified by Dr micranthidifolia) Also known as "bear lettuce" in southern Appalachia, the leaves of this plant have traditionally birch, hemlock Branch Lettuce (Saxifrage) Buttercup The plants in this picture were identified by Dr

Karsai, Istvan

454

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

ERIC Educational Resources Information Center

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)

Sinnett, E. Robert; And Others

1989-01-01

455

Otherness through Elves: Into Elfland and Beyond  

ERIC Educational Resources Information Center

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…

Yamazaki, Akiko

2008-01-01

456

Characterization of old \\  

Microsoft Academic Search

Wet boreal forests occur primarily in Atlantic Canada especially in Newfoundland, but examples are also found in Quebec and the northeastern U.S.A. These forests are dominated by balsam fir (Abies balsamea), which is susceptible to fire but flourishes in wetter environments where fire is absent. The major stand disturbances are caused by insects, primarily spruce budworm (Choristoneura fumiferana) and hemlock

Ian D. Thompson; David J. Larson; William A. Montevecchi

2003-01-01

457

VACUUM-PRESS DRYING OF THICK SOFTWOOD LUMBERS  

Microsoft Academic Search

In vacuum-press drying of softwood species, wood lemperaiure exhibited a low temperature gradient, and plateau temperature of core lasied during all stages of drying. The drying curves were close to “linear”. The drying rates of the short lumbers were higher for red pine and western hemlock, lower for white pine and similar for larch lumber compared to the long ones.

H. S. Jung; J. H. Lee; N. H. Lee

2000-01-01

458

Paper birch competitive effects vary with conifer tree species and stand age in interior British Columbia forests: implications for reforestation policy and practice  

Microsoft Academic Search

Paper birch (Betula papyrifera Marsh) is considered the most important competitive threat to commercially valuable conifers in the highly productive interior cedar–hemlock forests of British Columbia. It is routinely removed from conifer plantations at high cost to increase conifer growth rates and meet reforestation policy regulations. Competitive effects of paper birch and other neighbours on conifer growth were measured in

Suzanne W Simard; Donald L Sachs; Alan Vyse; Leandra L Blevins

2004-01-01

459

Fire-related landform associations of remnant old-growth trees in the southern Washington  

E-print Network

Fire-related landform associations of remnant old-growth trees in the southern Washington Cascade and divergent landform classes. Frequency analysis was used to test for landform associations. Live remnant western hemlock and western redcedar were strongly associated with convergent landforms and aspects

Vermont, University of

460

Gods behaving badly.  

PubMed

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

Retsas, Spyros

2015-02-01

461

Haida Food Gathering and Preparation.  

ERIC Educational Resources Information Center

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…

Cogo, Robert

462

South Florida Sun-Sentinel.com Nonprofits adding business skills  

E-print Network

South Florida Sun-Sentinel.com Nonprofits adding business skills By Doreen Hemlock, SunSentinel 4 easily rise to the top at nonprofit organizations. Today, as funders seek greater accountability and demand for social services spikes, nonprofit managers are finding they must boost their business skills

Fernandez, Eduardo

463

Comparison of nicotinic receptor binding and biotransformation of coniine in the rat and chick  

Microsoft Academic Search

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

Carol S. Forsythn; Robert C. Speth; Lynn Wecker; Francis D. Galey; Anthony A. Frank

1996-01-01

464

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...

465

Steroselective Potencies and Relative Toxicities of Coniine Enantiomers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Coniine, one of the major toxic alkaloids present in poison hemlock (Conium maculatum), occurs in two optically active forms. A comparison of the relative potencies of (+)- and (-)-coniine enantiomers has not been previously reported. In this study, we separated the enantiomers of coniine and dete...

466

Popular Botany  

Microsoft Academic Search

WE do not expect accurate scientific information from journalists; but so much confusion and error are seldom compressed into a small space as are to be found in a paragraph of which I send you extracts, cut from a London daily:-``A sad case of accidental poisoning by wild hemlock is reported from Tyne Dock. A little band of school children

Alfred W. Bennett

1893-01-01

467

50 CFR 32.68 - West Virginia.  

Code of Federal Regulations, 2011 CFR

... 5. We prohibit the marking of any tree or other refuge feature with flagging...the cutting and trimming of coniferous trees (balsam fir, red spruce, and hemlock...materials. 7. We prohibit permanent tree stands, but we allow use of...

2011-10-01

468

Dendrochronological dates of the Winkelman House, Gloucester, MA Carol B. Griggs  

E-print Network

, Massachusetts, and sent them to us at the Cornell Tree- Ring Laboratory along with information about the history; species of spruce cannot be discerned from wood alone). One sample with bark is a spruce sample. The tree-ring missing. Figure 2. The tree-ring patterns of the spruce (top) and hemlock (bottom) samples

Manning, Sturt

469

Canopy Carbon Gain and Water Use: Analysis of Old-growth Conifers in the Pacific Northwest  

Microsoft Academic Search

This report summarizes our current knowledge of leaf-level physiological processes that regulate carbon gain and water loss of the dominant tree species in an old-growth forest at the Wind River Canopy Crane Research Facility. Analysis includes measurements of photosynthesis, respiration, stomatal conductance, water potential, stable carbon isotope values, and biogenic hydrocarbon emissions from Douglas-fir ( Pseudotsuga menziesii), western hemlock (

William E. Winner; Sean C. Thomas; Joseph A. Berry; Barbara J. Bond; Clifton E. Cooper; Thomas M. Hinckley; James R. Ehleringer; Julianna E. Fessenden; Brian Lamb; Sarah McCarthy; Nate G. McDowell; Nathan Phillips; Mathew Williams

2004-01-01

470

Original article Dry matter and nitrogen allocation in western redcedar,  

E-print Network

October 1998; accepted 7 June 1999) Abstract - Seedlings of western red cedar (Thuja plicata Donn ex. D/branch components of western red cedar and Douglas fir, but not western hemlock, was an important source of N the high-N soils thanthe other species. The RDMI of western red cedar was intermediate between

Paris-Sud XI, Université de

471

Dr. Scott McG. Wilson MICFor Consultant Forester and Forest Ecologist  

E-print Network

group ­ Western Red Cedar and Coast Redwood, Japanese Cedar White group ­ Western Hemlock, Noble Fir and European/ Hybrid Larch Red group ­ Western Red Cedar and Coast Redwood, Japanese Cedar White group favours durable building timber Landscape diversity, red squirrels Resource small, older than average

472

Patterns of conifer tree regeneration following an autumn wildfire event in the western Oregon Cascade Range, USA  

E-print Network

.) Sarg. (western hemlock) and Thuja plicata Donn ex D. Don (western red cedar) (Munger, 1940). MorePatterns of conifer tree regeneration following an autumn wildfire event in the western Oregon and environmental conditions on conifer tree regeneration 11 years after an autumn wildfire in the western Oregon

Franklin, Jerry

473

GLOSSARY OF TERMS USED IN THIS TREE ID KEY Needle-shaped: More or less, sharp and pointy.  

E-print Network

GLOSSARY OF TERMS USED IN THIS TREE ID KEY Needle-shaped: More or less, sharp and pointy. Needles in Bundles Needles in Clusters Needles Single Tamarack Larch Pines Cedar Flat Needles Square or Round Needles Balsam Fir Hemlock Douglas-fir Spruces Douglas-fir Leaf Margin Toothed Leaf Margin Smooth Sugar Maple Red

474

Released on receipt but intended f o r use  

E-print Network

s t s were of the follow- ing species: Douglas f i r , western red cedar ,western hemlock, noble f i rAL OF TREE SESDS Some experiments have been made in the Pacific northwest by off iciale of the United of different velocities when released at the height of the average forest tree. The seeds used in&e t e

475

Litter breakdown and invertebrate association with three types of leaves in a temperate rainforest stream  

Microsoft Academic Search

Coniferous forests predominate in the boreal and western North American regions, yet most studies of litter breakdown in streams have focussed on litter from deciduous trees. We studied breakdown rates and invertebrate colonization of leaf litter from two common conifer species (western red cedar and western hemlock), along with red alder (a common riparian, deciduous species) in a small, coastal

John S. Richardson; Christel R. Shaughnessy; Paul G. Harrison

2004-01-01

476

Factors Affecting Infection of Precommercial Thinning Stumps by Heterobasidion annosum in Coastal British Columbia1  

E-print Network

(Bong.) Carr.] and western red cedar [Thuja plicate. Donn]. Second-growth stands are established 1966). Except for western red cedar, fresh stumps of the commercial species are susceptible hemlock zone (CWH). The commercial coniferous tree species in those zones are Douglas-fir [Pseudotsuga

Standiford, Richard B.

477

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...

478

Guidance and Technical Background Information for Biodiversity Management in  

E-print Network

Guidance and Technical Background Information for Biodiversity Management in the Interior Cedar is to share information with other forest professionals on biodiversity management in Interior Cedar Hemlock of the Integrated Land Management Bureau (ILMB) that this paper will provide useful information; however, ILMB would

Coxson, Darwyn

479

Oviposition traps to survey eggs of Lambdina fiscellaria (Lepidoptera: Geometridae).  

PubMed

Outbreaks of the hemlock looper, Lambdina fiscellaria (Gueneé), are characterized by rapid increase and patchy distribution over widespread areas, which make it difficult to detect impending outbreaks. This is a major problem with this insect. Population forecasting is based on tedious and expensive egg surveys in which eggs are extracted from 1-m branches; careful observation is needed to avoid counting old unhatched eggs of previous year populations. The efficacy of artificial substrates as oviposition traps to sample hemlock looper eggs was tested as a means of improving outbreak detection and population forecasting. A white polyurethane foam substrate (1,095 lb/ft3) used with the Luminoc insect trap, a portable light trap, was highly efficient in sampling eggs of the hemlock looper. Foam strips placed on tree trunks at breast height were less efficient but easier and less expensive to use for the establishment of extensive survey networks. Estimates based on oviposition traps were highly correlated with those obtained from the 1-m branch extraction method. The oviposition trap is a standard, inexpensive, easy, and robust method that can be used by nonspecialists. This technique makes it possible to sample higher numbers of plots in widespread monitoring networks, which is crucial for improving the management of hemlock looper populations. PMID:12852615

Hébert, Christian; Jobin, Luc; Auger, Michel; Dupont, Alain

2003-06-01

480

dopamine reuptake inhibitor, glucosidase inhibitor, sodium channel blocker and 5HT1D agonist9. In fact, alkaloid-containing plants have  

E-print Network

. In fact, alkaloid-containing plants have been recognized and exploited since ancient human civilization, from the utilization of Conium maculatum (hemlock) extract containing neurotoxin alkaloids to poison Socrates, to the use of coffee and tea as mild stimulants11. Today, numerous alkaloids are pharmacologi

Cai, Long

481

Ecology 2004 92, 464476  

E-print Network

. Intermediate disturbance in a late-successional hemlock-northern hardwood forest KERRY D. WOODS Natural Michigan, USA, experienced an unusually intense storm in July 2002. Permanent inventory plots and a 2.9-ha inventory plots). 3 Storm mortality differed from baseline mortality in patterns related to species and size

Woods, Kerry

482

I 1DWARF MISTLETOE CONTROLS I N BRITISH COLUMBIA-21G.A. Van Sickle and R.B. Smith-  

E-print Network

I 1DWARF MISTLETOE CONTROLS I N BRITISH COLUMBIA- 21G.A. Van Sickle and R.B. Smith- Abstract: The d mistletoe i n B r i t i s h Columbia, which mainly a f f e c t western hemlock, lodgepole pine, Douglas i a l and ground surveys, stand thinning, residual removals, treatment of advance regeneration

Standiford, Richard B.

483

Retention of canopy lichens after partial-cut harvesting in wet-belt interior cedarhemlock forests,  

E-print Network

Retention of canopy lichens after partial-cut harvesting in wet-belt interior cedar­hemlock forests of canopy lichens, but are subject to forest harvesting. If these distinctive canopy lichen communities-cutting techniques designed to retain old-growth attributes. The retention of canopy lichens after 30 and 70% partial

Northern British Columbia, University of

484

ORIGINAL PAPER Range expansion and population dynamics of co-occurring  

E-print Network

ORIGINAL PAPER Range expansion and population dynamics of co-occurring invasive herbivores Evan L and impact of both species by resurveying 142 hemlock stands across a 7,500 km2 latitudinal transect, running, with early-arriving species inducing changes in plant chemistry that negatively impact later-arriving species

Elkinton, Joseph

485

Ecology, 89(10), 2008, pp. 26712677 2008 by the Ecological Society of America  

E-print Network

-infested hemlocks, the benefit of co-occurring EHS infestations (reduced HWA density) may outweigh the cost and impact (i.e., the ``invasional meltdown'' hypothesis); however, exotic species might also act indirectly to slow the spread or blunt the impact of other invasives. On the east coast of the United States

Elkinton, Joseph

486

26 CFR 1.631-2 - Gain or loss upon the disposal of timber under cutting contract.  

Code of Federal Regulations, 2014 CFR

...within the meaning of section 631(b). The term evergreen trees is used in its commonly accepted sense and includes pine, spruce, fir, hemlock, cedar, and other coniferous trees. [T.D. 6500, 25 FR 11737, Nov. 26, 1960; 25 FR 14021,...

2014-04-01

487

26 CFR 1.631-2 - Gain or loss upon the disposal of timber under cutting contract.  

Code of Federal Regulations, 2011 CFR

...within the meaning of section 631(b). The term evergreen trees is used in its commonly accepted sense and includes pine, spruce, fir, hemlock, cedar, and other coniferous trees. [T.D. 6500, 25 FR 11737, Nov. 26, 1960; 25 FR 14021,...

2011-04-01

488