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1

Effect of root competition and shading on growth of suppressed western hemlock ( Tsuga heterophylla )  

Microsoft Academic Search

Factors suppressing the growth of Tsuga heterophylla, western hemlock, (40–200 cm tall) were separated into aboveground and belowground components. Canopy manipulation by creating gaps produced approximately a 30–34% increase in the overall amount of light available. Growth of the previously suppressed T. heterophylla was increased by minimizing root competition by trenching around individuals and to a much lesser degree by

E. Jennifer Christy

1986-01-01

2

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

Microsoft Academic Search

Anatomy and morphology of needles from six different 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. Trees were sampled from three stands, all of which originated following catastrophic fires, representing a chronosequence (15, 55 and 145 years old) of stand

A. D. Richardson; P. M. S. Ashton; G. P. Berlyn; M. E. McGroddy; I. R. Cameron

2001-01-01

3

Photodiscoloration of western hemlock ( Tsuga heterophylla ) sapwood III Early stage of photodiscoloration reaction with lignans  

Microsoft Academic Search

The reaction during the early stage of photodiscoloration of constituents in western hemlock [Tsuga heterophylla (Raf. Sarg., Pinaceae] sapwood was investigated with chemical methods. The main photodiscoloring constituents, hydroxymatairesinol,\\u000a allohydroxymatairesinol, ?-conidendrin, and oxomatairesinol, were used as substrates for light-irradiation experiments in\\u000a vitro. The structures of photodiscoloration reaction products were elucidated by isolation and instrumental analyses and\\/or\\u000a co-high-performance liquid chromatography analyses

Fumio Kawamura; Megumi Miyachi; Shingo Kawai; Hideo Ohashi

1998-01-01

4

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

5

Changes in Stomatal Frequency and Size During Elongation of Tsuga heterophylla Needles  

E-print Network

Changes in Stomatal Frequency and Size During Elongation of Tsuga heterophylla Needles LENNY L. R and epidermal cells of Tsuga heterophylla needles during different stages of budburst were measured using Annals of Botany Company Key words: Tsuga heterophylla, western hemlock, conifers, leaf maturation

Cochran-Stafira, D. Liane

6

Site index of western hemlock ( Tsuga heterophylla) in relation to soil nutrient and foliar chemical measures  

Microsoft Academic Search

To investigate the productivity of western hemlock, relationships between site index and forest floor, mineral soil, and foliar nutrient measures were examined in 101 immature western hemlock stands located in southern coastal British Columbia. Measures of both soil and foliar nitrogen were consistently identified as explanatory variables. In addition, measures of forest-floor-extractable K, mineral soil pH, C:N ratio, extractable K

Gordon J. Kayahara; Reid E. Carter; Karel Klinka

1995-01-01

7

EFFECT OF EXTRACTION ON WOOD DENSITY OF WESTERN HEMLOCK (TSUGA HETEROPHYLLA (RAF.) SARG.)  

Microsoft Academic Search

Extractives can account for between 1 to 20% of the oven-dry weight of wood of various tree species and can influence wood density values appreciably. Removing these chemical deposits (extraction) in wood samples can help establish a consistent baseline for comparing wood densities where extractives are expected to differ between sample parameters. Although western hemlock is a very important timber

Ryan Singleton; Dean S. DeBell; Barbara L. Gartner

2003-01-01

8

Micropropagation of western hemlock (Tsuga heterophylla [Raf.] Sarg.) from embryonic explants  

Microsoft Academic Search

An in vitro propagation protocol is described for western hemlock, an important forestry species in Canada. For shoot bud induction, embryonic explants were placed initially on one-third strength Schenk and Hildebrandt medium containing 5 µM N6-benzyladenine (BA) or 5 µM BA in combination with either 5 µM kinetin or 5 µM 2-isopentenyl adenine for 14 days. The explants were transferred

Indra S. Harry; Chin-Yi Lu; Kiran K. Sharma; Trevor A. Thorpe

1994-01-01

9

Sesquilignans and lignans from Tsuga heterophylla  

Microsoft Academic Search

Two epimeric sesquilignans and two lignans were isolated from the sapwood of Tsuga heterophylla (western hemlock, Pinaceae). By spectroscopic analyses their structures were deduced to be (8R,8?R,7?R,8?S,7?R)-7?-hydroxylappaol E and (8R,8?R,7?R,8?S,7?S)-epi-7?-hydroxylappaol E, and (8?R,7?S)-8-hydroxy-?-conidendrin and (8?R,7?S)-8-hydroxy-?-conidendric acid methyl ester. Their presence in several samples of western hemlock sapwood was confirmed by quantitative analyses.

Fumio Kawamura; Shingo Kawai; Hideo Ohashi

1997-01-01

10

Spatial distribution and succession of epiphytes on Tsuga heterophylla (western hemlock) in an old-growth Douglas-fir forest  

Microsoft Academic Search

We examined the distribution and abundance of nonvascular epiphytes on western hemlock trees in an old- growth coniferous forest focusing on patterns of epiphyte distribution at different spatial scales, epiphyte abundance amongst trees differing in size, and crown structures associated with epiphyte abundance. Total epiphyte cover was greatest in four canopy microhabitats: the upper canopy strata, crowns of large trees,

Betsy Lyons; Nalini M. Nadkarni; Malcolm P. North

2000-01-01

11

Conventional kiln drying and equalization of Western hemlock ( Tsuga heterophylla (Raf.)[Sarg]) to Japanese equilibrium moisture content  

Microsoft Academic Search

Density sorted, matched-samples of Western hemlock were dried in order to quantify the physical changes of conventionally kiln dried wood when exposed to the equilibrium moisture contents of a typical Japanese winter. Physical changes were monitored for 14 weeks by sampling board weight, dimensions, shell and core moisture contents (oven-dry basis) and warp. The difference of 7% in equilibrium moisture

J. W. Wallace; I. D. Hartley; S. Avramidis; L. C. Oliveira

2003-01-01

12

Lignans causing photodiscoloration of Tsuga heterophylla: 8-hydroxy-oxomatairesinol from sapwood  

Microsoft Academic Search

A lignan, (8S,8?S,)-(+)-8-hydroxy-oxomatairesinol, has been isolated from the sapwood of Tsuga heterophylla (western hemlock, Pinaceae). The known lignans matairesinol, lariciresinol and secoisolariciresinol were also obtained. The structure of the compound was established by 1D and 2D NMR spectroscopy. Results of the light-irradiation test of the lignans from T. heterophylla are also reported.

Fumio Kawamura; Shingo Kawai; Hideo Ohashi

2000-01-01

13

Four new species of yeast isolated from insect frass in bark of Tsuga heterophylla (Raf.) Sargent  

Microsoft Academic Search

Summary  In a study of the yeasts associated with insect frass underneath the bark ofTsuga heterophylla (the Pacific Coast hemlock) four new species of yeast were found. These were described asSporobolomyces singularis, Bullera tsugae, Cryptococcus skinneri andCandida oregonensis. Sporobolomyces singularis is a non-pigmented species, which required an amendment of the genus definition. Ballistospore formation of the new species\\u000a ofSporobolomyces and ofBullera

H. J. Phaff; Lidia do Carmo-Sousa

1962-01-01

14

Lignans causing photodiscoloration of Tsuga heterophylla: 8-hydroxy-oxomatairesinol from sapwood.  

PubMed

A lignan, (8S,8'S,)-(+)-8-hydroxy-oxomatairesinol, has been isolated from the sapwood of Tsuga heterophylla (western hemlock, Pinaceae). The known lignans matairesinol, lariciresinol and secoisolariciresinol were also obtained. The structure of the compound was established by 1D and 2D NMR spectroscopy. Results of the light-irradiation test of the lignans from T. heterophylla are also reported. PMID:10897486

Kawamura, F; Kawai, S; Ohashi, H

2000-06-01

15

Heterobasidion (Fomes) Annosum Incidence in Pre-Commercially Thinned Coastal Washington Western Hemlock Stands1  

E-print Network

hemlock (Tsuga heterophylla) and causes a root and butt-rot disease. A disease survey was initiated hemlock (Tsuga heterophylla (Rfn.) Sarg.) and causes a root and butt-rot disease (Russell and others

Standiford, Richard B.

16

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

E-print Network

-white pine-western hemlock (Abies grandis-Pinus monticola-Tsuga heterophylla) slash fuels. This paper reports. Habitat type is western hemlock/ Queencup beadlily (Tsuga heterophylla/Clintonia uniflora-Clin- tonia

Fried, Jeremy S.

17

Response of young Tsuga heterophylla to deer browsing: developing tools to assess deer impact on forest dynamics  

Microsoft Academic Search

We used dendroecology to describe and understand the consequences of deer browsing on regenerating western hemlock ( Tsuga heterophylla). We compared tree shape, growth rate, height and age at four different sites in Haida Gwaii (British Columbia, Canada) that had trees representative of the range of deer impact on trees: (1) trees showing no sign of browsing, (2) escaped trees

Bruno Vila; Franck Torre; Jean-Louis Martin; Frédéric Guibal

2003-01-01

18

The effect of fertilization on the below-ground diversity and community composition of ectomycorrhizal fungi associated with western hemlock ( Tsuga heterophylla )  

Microsoft Academic Search

Fertilization typically reduces ectomycorrhizal diversity shortly after its application but less is known about its longer-term\\u000a influence on fungal species. Long-term effects are important in forests where fertilizer is rarely applied. We compared fungal\\u000a species composition in western hemlock control plots with plots last fertilized 7 years ago with nitrogen (N) or nitrogen\\u000a plus phosphorus (N + P). The N +

Shannon H. A. Wright; Shannon M. Berch; Mary L. Berbee

2009-01-01

19

The effect of fertilization on the below-ground diversity and community composition of ectomycorrhizal fungi associated with western hemlock (Tsuga heterophylla).  

PubMed

Fertilization typically reduces ectomycorrhizal diversity shortly after its application but less is known about its longer-term influence on fungal species. Long-term effects are important in forests where fertilizer is rarely applied. We compared fungal species composition in western hemlock control plots with plots last fertilized 7 years ago with nitrogen (N) or nitrogen plus phosphorus (N + P). The N + P fertilization had a significant lingering effect, increasing the tree size and foliar P content of the western hemlocks. From ectomycorrhizal roots of 24-year-old trees from northern Vancouver Island, Canada, we identified fungi from 12 samples per treatment, by amplifying, cloning, and sequencing fungal ribosomal DNA fragments, placing sequences with 97% or more identity in the same operational taxonomic unit (OTU). Diversity was high across treatments; we detected 77 fungal OTUs, 52 from ectomycorrhizal genera, among 922 clone sequences. The five most frequent OTUs were similar in abundance across treatments. Only 19 OTUs matched any of the 197 previously reported ectomycorrhizal species of western hemlock. Species composition but not diversity in nitrogen plus phosphorus plots differed significantly from control or nitrogen plots. Two Cortinarius OTUs were indicator species for nitrogen plus phosphorus plots and presence of Cortinarius cinnamomeus was correlated with control or nitrogen plots. After 7 years, fertilization history had made no detectable difference in ectomycorrhizal fungal diversity, but long-lasting changes in environment resulting from fertilization had a lingering effect on fungal ectomycorrhizal species composition. PMID:19139932

Wright, Shannon H A; Berch, Shannon M; Berbee, Mary L

2009-04-01

20

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

21

Conidia of Heterobasidion annosum from Tsuga heterophylla forests in western Washington  

E-print Network

Conidia of Heterobasidion annosum from Tsuga heterophylla forests in western Washington TOMHSIANG of Heterobasidion annosurn from Tsuga heterophylla forests in western Washington. Can. J. Bot. 67: 1262 of Heterobasidion annosurn from Tsuga heterophylla forests in western Washington. Can. J. Bot. 67 : 1262- 1266. L

Hsiang, Tom

22

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

23

Wood density of young-growth western hemlock: relation to ring age, radial growth, stand density,  

E-print Network

-high stem sections were sampled from 56 western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees growing prélevées à hauteur de poitrine sur 56 pruches de l'Ouest (Tsuga heterophylla (Raf.) Sarg.) qui croissaient intensif. [Traduit par la Rédaction] DeBell et al. 2442 Introduction Western hemlock (Tsuga heterophylla

Lachenbruch, Barbara

24

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...

25

Spatial variation of climatic and non-climatic controls on species distribution: the range limit of Tsuga heterophylla  

Microsoft Academic Search

Aim To assess which climatic variables control the distribution of western hemlock (Tsuga heterophylla), how climatic controls vary over latitude and between disjunct coastal and interior sub-distributions, and whether non-climatic factors, such as dispersal limitation and interspecific competition, affect range limits in areas of low climatic control. Location North-western North America. Methods We compared four bioclimatic variables (actual evapotranspiration (AET),

Daniel G. Gavin; Feng Sheng Hu

2006-01-01

26

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

27

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

28

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

29

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

30

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

31

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

32

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

33

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

34

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

35

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

PubMed Central

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

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

2014-01-01

36

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

37

Discriminating Tsuga canadensis Hemlock Forest Defoliation Using Remotely Sensed Change Detection  

PubMed Central

The eastern hemlock (Tsuga Canadensis) is declining in health and vigor in eastern North America due to infestation by an introduced insect, the hemlock woolly adelgid (Adelges isugue). Adelgid feeding activity results in the defoliation of hemlock forest canopy over several years. We investigated the application of Landsat satellite imagery and change-detection techniques to monitor the health of hemlock forest stands in northern New Jersey. We described methods used to correct effects due to atmospheric conditions and monitor the health status of hemlock stands over time. As hemlocks defoliate, changes occur in the spectral reflectance of the canopy in near infrared and red wavelengths—changes captured in the Normalized Difference Vegetation Index. By relating the differences in this index over time to hemlock defoliation on the ground, four classes of hemlock forest health were predicted across spatially heterogeneous landscapes with 82% accuracy. Using a time series of images, we are investigating temporal and spatial patterns in hemlock defoliation across the study area over the past decade. Based on the success of this methodology, we are no expanding out study to monitor hemlock health across the entire Mid-Atlantic region. PMID:19265936

Royle, D. D.; Lathrop, R. G.

2002-01-01

38

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

39

The cellular distribution of lignans in Tsuga heterophylla wood  

Microsoft Academic Search

Western hemlock heartwood contains patches of tracheids with large amounts of cellular inclusions. Microscopic and chemical examination of the wood showed several types of deposits containing the lignans matairesinol, hydroxymatairesinol and conidendrin. The deposits, which were often relatively pure individual lignans, frequently assumed different physical forms and chemical composition. A check in the wood contained three distinct forms of deposits

R. L. Krahmer; R. W. Hemingway; W. E. Hillis

1970-01-01

40

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

Microsoft Academic Search

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

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

1999-01-01

41

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

42

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

43

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

44

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

45

Atmospheric CO2 fluctuations during the last millennium reconstructed by stomatal frequency analysis of Tsuga heterophylla needles  

Microsoft Academic Search

A stomatal frequency record based on buried Tsuga heterophylla needles reveals significant centennial-scale atmospheric CO2 fluctuations during the last millennium. The record includes four CO2 minima of 260 275 ppmv (ca. A.D. 860 and A.D. 1150, and less prominently, ca. A.D. 1600 and 1800). Alternating CO2 maxima of 300 320 ppmv are present at A.D. 1000, A.D. 1300, and ca.

Lenny Kouwenberg; Rike Wagner; Wolfram Kürschner; Henk Visscher

2005-01-01

46

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

47

Heterobasidion (Fomes) Annosum Incidence in Pre-Commercially Thinned Coastal Washington Western Hemlock Stands1  

Microsoft Academic Search

Heterobasidion annosum infects western € hemlock (Tsuga heterophylla) and causes a root and € butt-rot disease. A disease survey was initiated € in thinned Southwestern Washington hemlock stands € to determine current disease incidence caused by € H. annosum. € Eleven stands were selected which had been € pre-commercially thinned in the interval 5-11 € years ago. Ten replicate 1\\/50th

Willis R. Littke; John E. Browning

48

Genotype × shade effects for western hemlock  

Microsoft Academic Search

Western hemlock (Tsuga heterophylla (Raf.) Sarg.) families were grown under different levels of shade for 2 or 3 years at two nursery sites to determine whether families performed differently relative to one another in the differ- ent shade environments. Differences were found both for levels of shade and families, but no family x shade interac- tion was found. Results suggest

G. R. Johnson; C. Cartwright

2005-01-01

49

Predators associated with the hemlock woolly adelgid (Hemiptera: Adelgidae) in the Pacific Northwest.  

PubMed

The hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is causing widespread mortality of eastern hemlock, Tsuga canadensis L. Carrière, in the eastern United States. In western North America, feeding by A. tsugae results in negligible damage to western hemlock, Tsuga heterophylla (Raf.) Sargent. Host tolerance and presence of endemic predators may be contributing to the relatively low levels of injury to T. heterophylla caused by A. tsugae. Field surveys of the predator community associated with A. tsugae infestations on 116 T. heterophylla at 16 sites in Oregon and Washington were conducted every 4-6 wk from March 2005 through November 2006. Fourteen uninfested T. heterophylla were also surveyed across 5 of the 16 sites. Each sample tree was assigned an A. tsugae population score ranging from 0 to 3. Predators collected from A. tsugae-infested T. heterophylla represent 55 species in 14 families, listed in order of abundance: Derodontidae, Chamaemyiidae, Hemerobiidae, Coccinellidae, Cantharidae, Reduviidae, Miridae, Syrphidae, Chrysopidae, Coniopterygidae, Staphylinidae, Anthocoridae, Nabidae, and Raphidiidae. Laricobius nigrinus Fender (Coleoptera: Derodontidae), Leucopis argenticollis Zetterstedt (Diptera: Chamaemyiidae), and Leucopis atrifacies (Aldrich) (Chamaemyiidae) were the most abundant predators; together comprising 59% of predator specimens recovered. Relationships among predators and A. tsugae were determined through community structure analysis. The abundances of Laricobius spp. larvae, L. nigrinus adults, Leucopis spp. larvae, and L. argenticollis adults were found to be positively correlated to A. tsugae population score. Predators were most abundant when the two generations of A. tsugae eggs were present. L. argenticollis and L. atrifacies were reared on A. tsugae in the laboratory, and host records show them to feed exclusively on Adelgidae. PMID:18419922

Kohler, G R; Stiefel, V L; Wallin, K F; Ross, D W

2008-04-01

50

Ambrosia Beetle Host Selection Among Logs of Douglas Fir, Western Hemlock, and Western Red Cedar with Different Ethanol and ?-Pinene Concentrations  

Microsoft Academic Search

Logs from Douglas fir, Pseudotsuga menziesii; western hemlock, Tsuga heterophylla; and western red cedar, Thuja plicata, were left in the forest through winter. In April, segments from these logs were removed and randomly positioned adjacent to one another allowing ambrosia beetles to select their preferred host. In early June the tissues of Douglas fir and western hemlock logs contained significantly

Rick G. Kelsey; Gladwin Joseph

1997-01-01

51

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

52

Atmospheric CO2 fluctuations during the last millennium reconstructed by stomatal frequency analysis of Tsuga heterophylla needles  

NASA Astrophysics Data System (ADS)

A stomatal frequency record based on buried Tsuga heterophylla needles reveals significant centennial-scale atmospheric CO2 fluctuations during the last millennium. The record includes four CO2 minima of 260 275 ppmv (ca. A.D. 860 and A.D. 1150, and less prominently, ca. A.D. 1600 and 1800). Alternating CO2 maxima of 300 320 ppmv are present at A.D. 1000, A.D. 1300, and ca. A.D. 1700. These CO2 fluctuations parallel global terrestrial air temperature changes, as well as oceanic surface temperature fluctuations in the North Atlantic. The results obtained in this study corroborate the notion of a continuous coupling of the preindustrial atmospheric CO2 regime and climate.

Kouwenberg, Lenny; Wagner, Rike; Kürschner, Wolfram; Visscher, Henk

2005-01-01

53

Parasitoids reared from predators of hemlock woolly adelgid (Hemiptera: Adelgidae), and the hymenopterous parasitoid community on western hemlock in the Pacific Northwest.  

PubMed

In western North America, infestations of the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), are common on orchard, ornamental, and roadside western hemlock, Tsuga heterophylla (Raf.) Sargent. However, these infestations rarely cause T. heterophylla mortality. Host tolerance and presence of endemic predators may be contributing to the relatively low levels of injury to T. heterophylla caused by A. tsugae. Field surveys of the arthropod community associated with A. tsugae infestations on 116 T. heterophylla at 16 sites in Oregon and Washington were conducted every 4-6 wk from January 2005 through November 2006. Fourteen uninfested T. heterophylla were also surveyed across 5 of the 16 sites. Immature A. tsugae predators collected in the field were brought to the laboratory for rearing. Eight species of hymenopterous parasitoids were reared from pupae of predators of A. tsugae in the laboratory. Two Pachyneuron spp. (Pteromalidae) and a Melanips sp. (Figitidae) were reared from Leucopis spp. (Diptera: Chamaemyiidae) puparia. Syrphoctonus pallipes (Gravenhorst) (Ichneumonidae), Woldstedtius flavolineatus (Gravenhorst) (Ichneumonidae), Syrphophagus sp. (Encyrtidae), and Pachyneuron albutius Walker were reared from Syrphidae (Diptera) puparia. A Helorus sp. (Heloridae) was reared from a Chrysoperla sp. (Neuroptera: Chrysopidae) cocoon. Laboratory rearing did not show any direct association between parasitoids and A. tsugae. In the field survey, a total of 509 adult parasitic Hymenoptera representing 19 families and at least 57 genera were collected from T. heterophylla. Nonparametric analysis of community structure showed Pachyneuron spp. were strongly correlated to abundance of their Leucopis spp. hosts and to A. tsugae population score in the field. The possible impact of parasitism on Leucopis spp., potential A. tsugae biological control candidates for the eastern United States, is discussed. PMID:19161691

Kohler, G R; Stiefel, V L; Wallin, K F; Ross, D W

2008-12-01

54

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

PubMed Central

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

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

2007-01-01

55

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

56

Oribatid mite communities in the canopy of montane Abies amabilis and Tsuga heterophylla trees on Vancouver Island, British Columbia.  

PubMed

To study the oribatid mite community inhabiting microhabitats in the canopy of montane Abies amabilis [(Douglas ex D. Don) Lindl.] and Tsuga heterophylla [(Raf.) Sarg] tree species across five elevational sites, we collected 180 branch tips and 180 foliose/crustose lichen samples over three time periods. Thirty-three species of oribatid mites were identified from the study area. Mite species richness and abundance was significantly affected by microhabitat, and this association was independent of sampling time. At the microhabitat scale, distinct species assemblages were associated with lichen and branch tip habitats, and to a lesser degree, tree species. Conifer specificity was most apparent in the closely related species of Jugatala, where Jugatala tuberosa Ewing was only found on branch tips from A. amabilis and Jugatala sp. was primarily found on branch tips from T. heterophylla. Microhabitat specificity was most pronounced in Dendrozetes sp. where most individuals were found on branch tips and Anachiperia geminus Lindo et al. that occurred primarily on lichens. Principal components analysis of oribatid mite community composition further showed a high degree of association with microhabitat and tree species. Habitat profiles are difficult to discern for many species because tree, microhabitat, and elevation preferences confound distribution patterns. Given the significant tree-microhabitat associations in species composition in this montane canopy study, we suggest that sampling multiple microhabitats across elevations to look for patterns in community structure offers opportunities to explicitly test organizing principles in community ecology. PMID:18419918

Winchester, N N; Lindo, Z; Behan-Pelletier, V M

2008-04-01

57

Convergence of leaf display and photosynthetic characteristics of understory Abies amabilis and Tsuga heterophylla in an old-growth forest in southwestern Washington State, USA.  

PubMed

We compared the morphological and physiological characteristics of understory trees of Abies amabilis (Dougl. ex Loud.) Dougl. ex J. Forbes and Tsuga heterophylla (Raf.) Sarg. growing adjacent to each other in an old-growth forest in southwestern Washington State, USA. We hypothesized that, despite contrasting branching patterns and crown architectures, the two species should exhibit convergence in leaf display and photosynthetic gain per light intercepting area, because these are important properties determining their survival in the light-limited understory. The branching pattern of A. amabilis was regular (normal shoot-length distribution, less variable branching angle and bifurcation ratio), whereas that of T. heterophylla was more plastic (positively skewed shoot-length distribution, more variable branching angle and bifurcation ratio). The two species had similar shoot morphologies: number of leaves per unit shoot length and leaf to axis dry mass ratio. Leaf morphology, in contrast, was significantly different. Leaves of A. amabilis were larger and heavier than those of T. heterophylla, which resulted in lower mass-based photosynthetic rate for A. amabilis. Despite these differences, the two species had similar levels of leaf overlap and area-based photosynthetic characteristics. Needle longevity of A. amabilis was nearly twice that of T. heterophylla. The leaf N contents of current and 1-year-old leaves were lower for A. amabilis than for T. heterophylla. However, the leaf N content of A. amabilis did not change from current leaves to 6-year-old leaves, whereas that of T. heterophylla decreased with increasing leaf age. Abies amabilis had deeper crowns than T. heterophylla and retained branches with low relative growth rates. Longer branch retention may compensate for the lower branch-level assimilation rate of A. amabilis. We inferred that the convergence of leaf display and photosynthetic characteristics between A. amabilis and T. heterophylla may contribute to the persistence of both species in the understory of this forest. PMID:19525494

Ishii, Hiroaki; Yoshimura, Ken-Ichi; Mori, Akira

2009-08-01

58

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

59

Abundance and attributes of wildlife trees and coarse woody debris at three silvicultural systems study areas in the Interior Cedar-Hemlock Zone, British Columbia  

Microsoft Academic Search

Unmanaged cedar (Thuja plicata)-hemlock (Tsuga heterophylla) forests of the northern Interior Wetbelt of British Columbia support standing and dead trees with a variety of structural features that provide habitat for wildlife. We describe the pre-harvest abundance and characteristics of wildlife trees (standing trees with special characteristics that provide habitat for wildlife) and coarse woody debris (CWD) at three silvicultural systems

Susan K. Stevenson; Michael J. Jull; Bruce J. Rogers

2006-01-01

60

western hemlock, and western redcedar seedlings to manipulated levels of overstory and understory competition1  

Microsoft Academic Search

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western redcedar (Thuja plicata Donn ex D. Don) seedlings were planted in March 2001 within three clearcut- harvested, shelterwood, or thinned stands of mature Douglas-fir near Olympia, Washington. From 2002 to 2005, areas of vegetation control of 0, 4.5, or 9 m2 were maintained with herbicides around a

Timothy B. Harrington

61

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

62

Comparing productivity of pure and mixed Douglas-fir and western hemlock plantations in the Pacific Northwest  

Microsoft Academic Search

We studied pure and 50\\/50 mixtures of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) plantations to compare attained total yields between mixed-species stands as opposed to monocultures of equal densities. Whether overall stand density influences this outcome has not been adequately investigated, and to address this we included three density levels (494, 1111, and 1729

M. M. Amoroso; E. C. Turnblom

2006-01-01

63

Journal of the Torrey Botanical Society 132(4), 2005, pp. 602612 Disjunct eastern hemlock (Tsuga canadensis) stands at its  

E-print Network

Kenneth Wills, Jr., Robert Aldridge, Ro- land Roby, the Eisenbarth family, and Sara Hart for assistance (Tsuga canadensis) stands at its southern range boundary1 Justin L. Hart2,3 and David Shankman Department of Geography, University of Alabama, Box 870322, Tuscaloosa, AL 35487 HART, J. L. AND D. SHANKMAN (Department

Hart, Justin

64

Five-year growth responses of Douglas-f ir, western hemlock, and western redcedar seedlings to manipulated levels of overstory and understory competition1  

Microsoft Academic Search

Douglas-fir (Pseudotsuga mnziesii (Mirh) Franw), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western redcedar (Thuja plicata Donn ex D. Don) seedlings were planted in March 2001 within three clearcut- harvested, shelterwood, or thinned stands of mature Douglas-fir near Olympia, Washington. From 2002 to 2005, areas of vegetation control of 0, 4.5, or 9 mZ were maintained with herbicides around a

Timothy B. Harrington

2006-01-01

65

Growth and yield of all-aged Douglas-fir – western hemlock forest stands: a matrix model with stand diversity effects  

Microsoft Academic Search

A density-dependent matrix model was developed for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) - western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest stands in the Pacific Northwest of the United States. The model predicted the number and volume of trees for 4 species groups and 19 diameter classes. The parameters were based on species-dependent equations linking individual tree growth, mortality, and stand

Jingjing Liang; Joseph Buongiorno; Robert A. Monserud

2005-01-01

66

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

67

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

68

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

69

Composition, Structure, and Sustaina bility of Hemlock Ecosystems in Eastern North America  

Microsoft Academic Search

Across its natural range in North America, eastern hemlock (Tsuga canadensis (L.) Carriere) is an important resource for people and wildlife, but it is seriously threatened by the hemlock woolly adelgid (HWA) (Adelges tsugae Annand). From 10 to 20 percent of the hemlock resource is found in the Canadian provinces of New Brunswick, Nova Scotia, Ontario, Prince Edward Island, and

William H. Mc Williams; Thomas L. Schmidt

70

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

71

Vertical gradients in photosynthetic light response within an old-growth Douglas-fir and western hemlock canopy.  

PubMed

We examined needle-level light response of photosynthesis across a vertical light gradient within 45-55-m-tall western hemlock (Tsuga heterophylla (Raf.) Sarg.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees growing in a 400-500-year-old mixed species stand. We determined: (1) whether light-saturated photosynthetic rates, light compensation points, and respiration rates varied from the upper to the lower canopy, and (2) if light-saturated photosynthetic rates, light compensation points, and respiration rates varied between Douglas-fir and western hemlock. Over a 25-m gradient from the canopy top to the lower canopy, mean light-saturated photosynthetic rates, light compensation points, and respiration rates declined in overstory Douglas-fir and western hemlock needles, paralleling a 65% decline in the mean daily photosynthetic photon flux density (PPFD). At the canopy top, increasing light-saturated photosynthetic rates relative to lower canopy needles increased carbon uptake at high PPFD. In the lower canopy, reduced respiration rates relative to upper canopy needles increased carbon uptake at low PPFD by reducing the light compensation point. At all canopy positions, western hemlock had lower mean light-saturated photosynthetic rates, light compensation points and respiration rates than Douglas-fir. As a result, western hemlock had higher net photosynthetic rates at low PPFD, but lower net photosynthetic rates at high PPFD compared with Douglas-fir. PMID:12651440

Lewis, J. D.; McKane, R. B.; Tingey, D. T.; Beedlow, P. A.

2000-04-01

72

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

73

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

74

USDA Forest Service Gen. Tech. Rep. PSW-GTR-181. 2002. 435 Comparing Deterioration and Ecosystem  

E-print Network

hemlock (Tsuga heterophylla). The heartwood of yellow-cedar contains compounds that inhibit decay. Most of research has focused on the mortality of trees in the western hemlock (Tsuga heterophylla) dominated old

Standiford, Richard B.

75

USDA Forest Service Gen. Tech. Rep. PSW-GTR-181. 2002. 503 A Coarse Wood Dynamics Model for the  

E-print Network

hemlock (Tsuga heterophylla) snags and down logs in forested ecosystems of the western Cascades of Oregon-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) snags and logs. The model predicts snag fall

Standiford, Richard B.

76

Current and predicted long-term effects of deer browsing in hemlock forests in Michigan, USA  

Microsoft Academic Search

Remnants of virgin hemlock Tsuga canadensis (L.) Carr. forest in the Porcupine Mountains, Michigan, USA, have experienced inadequate hemlock regeneration lasting several decades. White-tailed deer Odocoileus virginianus Zimmermann browsing seems to be the major cause of the observed decline of hemlock regeneration, rather than poor seedbed conditions or changing climate. In some areas, -significant changes in the size-structure of the

Lee E. Frelich; Craig G. Lorimer

1985-01-01

77

Forest Dynamics Of Two Multi-Aged Hemlock-Mixed Mesophytic Forests In The Northern Cumberland Plateau, Kentucky  

Microsoft Academic Search

Tsuga canadensis (eastern hemlock) is a foundation species that performs a unique ecological role within the Appalachian mixed mesophytic forest of the eastern United States. However, the non-native hemlock woolly adelgid (HWA; Adelges tsugae Annand), a novel invasive colonizer, is significantly altering the natural processes within T. canadensis ecosystems. Few studies have documented T. canadensis forests before, during, and after

Kacie Lee Tackett

2012-01-01

78

Hemlock woolly adelgid (Hemiptera: Adelgidae) induces twig volatiles of eastern hemlock in a forest setting.  

PubMed

The hemlock woolly adelgid (Adelges tsugae Annand) is an invasive species causing high mortality of eastern hemlock (Tsuga canadensis (L) Carriere) in the forests of eastern North America. Recent findings revealed that sapling eastern hemlocks artificially infested with hemlock woolly adelgid in a plantation setting responded to the insect with an array of induced resin volatile changes. Here we determine if eastern hemlocks growing beneath a forest canopy respond to hemlock woolly adelgid infestation with the same patterns of constitutive and inducible volatile resin production as those plantation specimens. We inoculated previously uninfested branches of mature and immature hemlocks in a central New England forest with hemlock woolly adelgid. We then sampled twig tissue of infested and uninfested trees in late spring, early summer, and mid-autumn, after known intervals of adelgid activity when an induced response might be expected. We identified and quantified resin volatiles by gas chromatography-mass spectrometry. Constitutive levels of total monoterpenoids, sesquiterpenoids, and combined resin volatiles were all several-fold more abundant in forest trees than those previously measured in a plantation setting, pointing to further study of the influence of site factors on hemlock volatile production. Hemlock woolly adelgid infestation induced an array of changes in eastern hemlock's volatile profile, including many-fold increases in benzyl alcohol and methyl salicylate accumulation. Despite differences in constitutive concentrations of volatiles between the two sites, our findings verify that hemlock woolly adelgid elicits patterns of resin volatile induction in forest-grown eastern hemlocks quite similar to those previously observed in plantation grown trees. PMID:25259691

Pezet, Joshua; Elkinton, Joseph S

2014-10-01

79

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

PubMed

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

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

2003-08-01

80

Structural characteristics and canopy dynamics of Tsuga canadensis in forests of the southern Appalachian Mountains, USA  

Microsoft Academic Search

Tsuga canadensis (L.) Carr. forests of the southern Appalachian Mountains are currently facing imminent decline induced by a nonnative insect\\u000a pest, the hemlock woolly adelgid (Adelges tsugae Annand). To effectively manage these forest systems now and in the future, land managers need baseline data on forest structure\\u000a and dynamics prior to large-scale Tsuga canadensis mortality. Most of our knowledge concerning

Joshua A. Kincaid; Albert J. Parker

2008-01-01

81

Genetic considerations in cloning western hemlock  

SciTech Connect

Using clones to regenerate a species new to clonal reforestation presents the forest manager with many problems. A number of interrelated and interdependent research and development activities are needed to answer these technical questions. Network diagramming was used for scheduling research activities and for indicating interdependencies among activities. The resultant diagram, although developed specifically for western hemlock (Tsuga heterophylla (Raf.) Sarg.), represents a program which may be used for other species in which clonal reforestation is considered to be potentially appropriate. Once the network diagram was completed, several activities were examined in detail by experiments. The first group of activities dealt specifically with clonal variation (and its components) for five rooting traits and demonstrated that clonal variation was due to both genetic and C effects (persistent environmental effects). The potential bias to genotypic values of clones due to C effects is significant, but heritability and gain estimates are only slightly biased. The five rooting traits were highly heritable (H = 0.87 to 0.92), and predicted genetic gain from clonal selection was substantial. Genetic correlations between pairs of traits were generally high (0.66 to 0.99); therefore, when selecting for any one trait, correlated responses can be expected in other traits. The second group of activities examined components of clonal variation for juvenile height (HT) as well as associations between rooting traits and subsequent height growth of rooted cuttings. As with the rooting traits, C effects in HT were a significant proportion of the total genetic variation. HT was found to be under strong genetic control (H = 0.81), and genetic correlations between HT and rooting traits ranged from 0.37 to 0.59.

Foster, G.S. Jr.

1983-01-01

82

Xylem cavitation and loss of hydraulic conductance in western hemlock following planting.  

PubMed

Following planting, western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings experience water stress and declining xylem pressure potential (Psi(x)). Low Psi(x) can result in xylem cavitation and embolism formation, causing a decline in hydraulic conductance. This study focused on the relationship between Psi(x), xylem cavitation and transpiration (E) of newly planted seedlings. Leaf specific hydraulic conductance (k(AB)) declined from 0.56 to 0.09 mmol m(-2) s(-1) MPa(-1) over a 9-day period. Stomatal conductance (g(s)) declined from 143.5 to 39.15 mmol m(-2) s(-1) over the same period without an associated change in environmental conditions. A vulnerability profile indicated a 30% loss in hydraulic conductivity when seedlings experienced a Psi(x) between -2.5 and -3.0 MPa. A Psi(x) of -4.0 MPa led to a complete loss of conductivity. We conclude that following planting, western hemlock seedlings often experience Psi(x) values that are low enough to cause xylem cavitation and a decline in k(AB). PMID:14759915

Kavanagh, K L; Zaerr, J B

1997-01-01

83

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

84

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.

85

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

PubMed

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

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

2013-08-01

86

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

E-print Network

a low seedling survival in mature hemlock (Tsuga heterophylla (Raf.) Sarg.) ­ amabilis fir (Abies, ont un faible taux de survie dans les peuplements murs de pruche (Tsuga heterophylla (Raf.) Sarg.) et

Gilbert, Benjamin

87

Dendrochronologia 22 (2005) 163168 ORIGINAL ARTICLE  

E-print Network

-fir (Pseudotsuga menziesii (Mirb.) Franco), and western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees. The models built to represent the radial growth behaviour of mountain hemlock (Tsuga mertensiana (Bong.) Carr

Walters, Bradley B.

88

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

PubMed

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

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

2014-02-01

89

Patchy Invasion and the Origin of a Hemlock-Hardwoods Forest Mosaic  

Microsoft Academic Search

The record of forest invasion by eastern hemlock (Tsuga canadensis) during the course of Holocene migration provides useful information about invasion processes in temperate forest, a system that has been invaded by few exotic species. We used fossil pollen preserved in small forest hollows, which record forest composition on the scale of 1-3 ha, to study hemlock invasion of forests

Margaret B. Davis; Randy R. Calcote; Shinya Sugita; Hikaru Takahara

1998-01-01

90

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

PubMed

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

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

2007-01-01

91

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.

92

Assessing the potential impacts to riparian ecosystems resulting from hemlock mortality in Great Smoky Mountains National Park.  

PubMed

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. PMID:19495859

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

2009-08-01

93

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

94

Canopy light transmittance in Douglas-fir--western hemlock stands.  

PubMed

We measured vertical and horizontal variation in canopy transmittance of photosynthetically active radiation in five Pseudotsuga menziesii (Mirb.) Franco-Tsuga heterophylla (Raf.) Sarg. (Douglas-fir-western hemlock) stands in the central Cascades of southern Washington to determine how stand structure and age affect the forest light environment. The shape of the mean transmittance profile was related to stand height, but height of mean maximum transmittance was progressively lower than maximum tree height in older stands. The vertical rate of attenuation declined with stand age in both the overstory and understory. A classification of vertical light zones based on the mean and variance of transmittance showed a progressive widening of the bright (low variance and high mean) and transition (high variance and rapid vertical change) zones in older stands, whereas the dim zone (low variance and mean) narrowed. The zone of maximum canopy surface area in height profiles, estimated by inversion of transmittance profiles, changed from relatively high in the canopy in most young stands ("top-heavy") to lower in the canopy in older stands ("bottom-heavy"). In the understory, all stands had similar mean transmittances, but the spatial scale of variation increased with stand age and increasing crown size. The angular distribution of openness was similar in all stands, though the older stands were less open at all angles than the younger stands. Understory openness was generally unrelated to transmittance in the canopy above. Whole-canopy leaf area indices, estimated using three methods of inverting light measurements, showed little correspondence across methods. The observed patterns in light environment are consistent with structural changes occurring during stand development, particularly the diversification of crowns, the creation of openings of various sizes and the elaboration of the outer canopy surface. The ensemble of measurements has potential use in distinguishing forests of differing ages that have similar stature. PMID:11830411

Parker, Geoffrey G; Davis, Melinda M; Chapotin, Saharah Moon

2002-02-01

95

2005 Blackwell Publishing Ltd www.blackwellpublishing.com/geb DOI: 10.1111/j.1466-822x.2005.00171.x 491 Global Ecology and Biogeography, (Global Ecol. Biogeogr.) (2005) 14, 491501  

E-print Network

hemlock (Tsuga heterophylla). We calculated and projected nine climatic and water-balance variables to a 2 selec- tion,regression tree analysis,response surfaces,Tsuga heterophylla,western hemlock-km grid up to 140 km from the T. heterophylla range. Models were trained using the five variables

Gavin, Daniel G.

96

Direct inhibition of maintenance respiration in western hemlock roots exposed to ambient soil carbon dioxide concentrations.  

PubMed

Root respiration often exhibits a direct and immediate decline with increasing concentrations of ambient soil carbon dioxide concentration ([CO(2)]), and recent evidence suggests this decline may be attributable to a decline in maintenance respiration within the root. If true, this concept could provide a clue to the biochemical process underlying respiratory inhibition as well as improve our knowledge of the timing and degree to which this inhibition occurs in nature. To test the hypothesis that maintenance respiration exhibits a direct, negative response to increasing [CO(2)], we measured total respiration in intact root systems of western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings grown at different relative growth rates and exposed to soil [CO(2)]s ranging from 91 to 7008 &mgr;mol mol(-1). Analysis of covariance was used to separate maintenance from total respiration. Total respiration declined exponentially with increasing [CO(2)]. Maintenance respiration, which comprised 85% of total respiration over all treatments, also declined exponentially with increasing [CO(2)]. Growth respiration was not inhibited at any [CO(2)]. These findings may explain why roots of some fast-growing species do not show [CO(2)] inhibition. PMID:12651534

McDowell, Nate G.; Marshall, John D.; Qi, Jingen; Mattson, Kim

1999-07-01

97

Carbon isotope discrimination in western hemlock and its relationship to mineral nutrition and growth.  

PubMed

Western hemlock (Tsuga heterophylla [Raf.] Sarg.) is a major component of temperate rainforests in coastal British Columbia. Forest fertilization can enhance the growth of forest trees, but results are inconsistent for western hemlock. We investigated the relationship between delta13C (foliage and stemwood), growth response and tree nutritional status in this species. To establish a sampling protocol for stemwood, we first assessed spot-to-spot variation around and along the bole, which exceeded 1 per thousand. We utilized the reaction wood (high lignin content) and adjacent normal wood in two curved western hemlock stems to evaluate whether this variation was related to wood composition. There was a consistent 3.43 per thousand difference between lignin and holocellulose, but the isotopic mass balance of whole wood was conserved and, therefore, did not vary with lignin content. Therefore, extraction of cellulose or holocellulose prior to analysis can introduce (not remove) bias. In a detailed study of a third stem, circumferential and longitudinal variation in delta13C was associated with spiral grain indicating limited physiological mixing of isotopic signatures originating from the crown. Wood was subsequently pooled from four cardinal positions around each stem. Eight even-aged western hemlock stands were selected and fertilized with different combinations of nitrogen (N), phosphorous (P) and a blend of S, K, Mg, Zn and Cu. Fertilization was effective in increasing foliar N, P, K and S depending on treatment. At the end of the first growing season after fertilization, the effect of treatments on foliar delta13C was nearly significant (P = 0.054), but did not persist into a second year. Effects on tree-ring delta13C were more obvious and persisted for about 3 years, averaging approximately 0.2-0.4 per thousand over this period, depending on treatment. Combinations of N, P and blend had the greatest effect, consistent with relative increases in basal area increment. Effects of fertilizer additions on delta13C, though clear, were superimposed on larger site and annual weather-related patterns in delta13C. Large tree-to-tree variation in delta13C was positively correlated with basal area increment, both before and after treatment imposition, suggesting that high water-use efficiencies are associated with greater growth. PMID:20395303

Walia, Ankit; Guy, Robert D; White, Barry

2010-06-01

98

M. Ivkovich and M. KoshyOptimization of multiple trait selection Original article  

E-print Network

of multiple trait selection in western hemlock (Tsuga heterophylla (Raf.) Sarg.) including pulp and paper different selection indices in multiple breeding populations. Tsuga heterophylla / wood quality / index propriétés de la pâte et du papier chez (Tsuga heterophylla (Raf.) Sarg.). Nous avons étudié plusieurs

Paris-Sud XI, Université de

99

Original article Dry matter and nitrogen allocation in western redcedar,  

E-print Network

. Don), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and Douglas fir (Pseudotsuga menziesii (Mirb allocation de l'azote dans des semis de Thuja plicata, Tsuga heterophylla et Douglas poussant en condition de sols pauvres et riches en azote. Des semis de Thuja plicata Don ex. D. Don, de Tsuga heterophylla (Raf

Paris-Sud XI, Université de

100

Spatial variation of climatic and non-climatic controls on species  

E-print Network

: the range limit of Tsuga heterophylla Daniel G. Gavin* and Feng Sheng Hu Department of Plant Biology variables control the distribution of western hemlock (Tsuga heterophylla), how climatic controls vary over has not completely expanded into its potential habitat. Tsuga heterophylla became common

Gavin, Daniel G.

101

FOREST ENTOMOLOGY Comparison of Numerical Response and Predation Effects of Two  

E-print Network

, Tsuga heterophylla Sargent, stands in northern Cali- fornia and Oregon in the 1920s (Annand 1924 J. Econ. Entomol. 96(3): 763Ð767 (2003) ABSTRACT The hemlock woolly adelgid, Adelges tsugae Annand (Tsuga canadensis Carriere) and Carolina hemlock (Tsuga caroliniana Englemann) in the eastern United

Elkinton, Joseph

102

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

103

The co-occurrence of ectomycorrhizal, arbuscular mycorrhizal, and dark septate fungi in seedlings  

E-print Network

pine), Pinus ponderosa Dougl. ex C. Lawson (ponderosa pine), Tsuga heterophylla (Raf.) Sarg. (western- fir) and Tsuga mertensiana (Bong.) Carr. (mountain hemlock) when used as bait plants grown in soil

Massicotte, Hugues

104

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.

105

USDA Forest Service Gen. Tech. Rep. PSW-GTR-181. 2002. 479 Dead Wood and Fire Relationships in  

E-print Network

, and Umpqua National Forests in areas that are characterized as Western Hemlock Plant Series (Tsuga heterophylla is the climax tree species). The Western Hemlock Series is partitioned into 14 plant associations

Standiford, Richard B.

106

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

107

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

108

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.

109

Local and regional variation in hemlock seedling establishment in forests of the upper Great Lakes region, USA  

Microsoft Academic Search

Successful tree regeneration requires both successful seedling establishment and subsequent survival and growth sufficient to ensure recruitment. We examined patterns of initial seedling establishment in randomly selected stands of eastern hemlock (Tsuga canadensis) distributed across northern Wisconsin and eastern Upper Michigan. In 1990, we counted all hemlock seedlings (defined as 4–29cm tall) and sampled substrate conditions in two 7×7m quadrats

Thomas P. Rooney; Donald M. Waller

1998-01-01

110

108 2010 USDA Research Forum on Invasive Species GTR-NRS-P-75 NOTES ON THE BIOLOGY OF SCYMNUS (PULLUS)  

E-print Network

heterophylla, infested with the hemlock woolly adelgid, Adelges tsugae Annand. Sampling was done during. coniferarum adults from several locations in the Seattle, WA, metropolitan area from western hemlock, Tsuga these species. We have reared S. coniferarum through two complete generations in the laboratory on A. tsugae

111

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

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

Nickrent, Daniel L.

112

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

113

Ion Cycling in Hemlock-Northern Hardwood Forests of the Southern Lake Superior Region: A Preliminary Study  

Microsoft Academic Search

Southern Lake Superior Uplands makes it difficult to study biogeochemical processes as they relate to forest Upland forests of the southern Lake Superior region are diverse productivity and human disturbance effects. and contain a shifting mosaic of eastern hemlock (Tsuga canadensis (L.) Carr.) and northern hardwood forests dominated by sugar maple This study examines the influence of (i) forest cover

J. G. Bockheim; S. E. Crowley

114

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Authority for Subzone Status, Hemlock Semiconductor Corporation, (Polysilicon), Hemlock...polysilicon manufacturing facility of Hemlock Semiconductor Corporation, located in Hemlock...polysilicon at the facility of Hemlock Semiconductor Corporation, located in...

2013-04-10

115

Density-dependent survival and fecundity of hemlock woolly adelgid (Hemiptera: Adelgidae).  

PubMed

The hemlock woolly adelgid (Adelges tsugae Annand) has decimated eastern hemlocks (Tsuga canadensis Carrière) in forests throughout the eastern United Sates, but its densities in central New England appear to have stabilized. To find out why, we infested 64 eastern hemlocks with varying densities of adelgid ovisacs in a typical eastern hemlock forest in western Massachusetts. We subsequently documented adelgid density, fecundity, and the amount of new growth on experimental trees over two consecutive years. We used a 2 by 2 randomized block design using previously and newly infested hemlocks that were either 1-m tall saplings or branches of mature trees. There was a density-dependent decline in the survival and fecundity of adelgid in both the spring and winter generations. This response was a function of both previous infestation by adelgid and current year's crawler density in the spring generation. Additionally, the production of sexuparae in the spring generation played a key role in the overall density-dependent survival of adelgid, suggesting that sexuparae production is strongly linked to developing crawler density. PMID:25203223

Sussky, Elizabeth M; Elkinton, Joseph S

2014-10-01

116

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

117

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

118

Visual Ability and Searching Behavior of Adult Laricobius nigrinus, a Hemlock Woolly Adelgid Predator  

PubMed Central

Very little is known about the searching behavior and sensory cues that Laricobius spp. (Coleoptera: Derodontidae) predators use to locate suitable habitats and prey, which limits our ability to collect and monitor them for classical biological control of adelgids (Hemiptera: Adelgidae). The aim of this study was to examine the visual ability and the searching behavior of newly emerged L. nigrinus Fender, a host-specific predator of the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Phylloxeroidea: Adelgidae). In a laboratory bioassay, individual adults attempting to locate an uninfested eastern hemlock seedling under either light or dark conditions were observed in an arena. In another bioassay, individual adults searching for prey on hemlock seedlings (infested or uninfested) were continuously video-recorded. Beetles located and began climbing the seedling stem in light significantly more than in dark, indicating that vision is an important sensory modality. Our primary finding was that searching behavior of L. nigrinus, as in most species, was related to food abundance. Beetles did not fly in the presence of high A. tsugae densities and flew when A. tsugae was absent, which agrees with observed aggregations of beetles on heavily infested trees in the field. At close range of prey, slow crawling and frequent turning suggest the use of non-visual cues such as olfaction and contact chemoreception. Based on the beetles' visual ability to locate tree stems and their climbing behavior, a bole trap may be an effective collection and monitoring tool. PMID:22220637

Mausel, D.L.; Salom, S.M.; Kok, L.T.

2011-01-01

119

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

E-print Network

-Britannique dominées par la pruche de l'Ouest (Tsuga heterophylla (Raf.) Sarg.) et le thuya géant (Thuja pli- cata Donn the method using data from forests of northern, interior British Columbia dominated by western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western redcedar (Thuja plicata Donn ex D. Don). For both species, the most

120

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

E-print Network

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

Fried, Jeremy S.

121

Structure and composition of corticolous epiphyte communities in a Sierra Nevada old-growth mixed-conifer forest  

E-print Network

recently studied in Pacific Northwest Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) forests west of the Cascade crest (e.g., Clement & Shaw 1999; Lyons et al. 2000; McCune 1993; Mc

North, Malcolm

122

DWARF MISTLETOE CONTROL ON THE ROGUE RIVER NATIONAL FOREST IN ORE GO^^  

E-print Network

the climate is monticola), and some western hemlock essentially warm and moist in the winter, (Tsuga heterophylla). But at the same time, but hot and dry in the summer. we are cursed by 5 species of dwarf

Standiford, Richard B.

123

Understory Diversity and Succession on Coarse Woody Debris in a Coastal, Old-growth Forest, Oregon.  

E-print Network

?? This research examines the relationship between understory plant diversity and logs in a Pacific Northwest (PNW) Sitka spruce (Picea sitchensis)-western hemlock (Tsuga heterophylla) old-growth,… (more)

Mcdonald, Shannon Lee

2013-01-01

124

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 plicata) on Vancouver Island, British Columbia, Canada, to test for intra- and interspeci®c density

He, Fangliang

125

Height growth and vertical development of an old-growth Pseudotsuga - Tsuga forest in southwestern Washington State, U.S.A  

Microsoft Academic Search

A detailed analysis of diameter-height relationships was applied to an old-growth Pseudotsuga menziesii (Mirb.) Franco var. menziesii - Tsuga heterophylla (Raf.) Sarg. forest in southwestern Washington State, U.S.A., to pre- dict future development of vertical stratification among tree species. Differences among species in relative abundance and size structure resulted in diameter-height regressions of varying certainty and stability. Damage and shading

Hiroaki Ishii; Joel H. Reynolds; E. David Ford; David C. Shaw

2000-01-01

126

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

127

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

128

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

PubMed

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

129

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

130

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

131

Forest structure and regeneration in the Tsuga heterophylla - Abies amabilis transition zone, central Western Cascades, Oregon.  

E-print Network

??The dynamics of stands in the mid-elevation old-growth Douglas-fir (Pseudotsuga menziesii) forests of the central western Oregon Cascade Range were investigated using stand structure analysis.… (more)

Stewart, Glenn H.

1984-01-01

132

Changes in Stomatal Frequency and Size During Elongation of Tsuga heterophylla Needles  

Microsoft Academic Search

Background and Aims The inverse relationship between the number of stomata and atmospheric CO2 levels observed in different plant species is increasingly used for reconstructions of past CO2 concentrations. To validate this relationship, the potential influence of other environmental conditions and ontogenetical development stage on stomatal densities must be investigated as well. Quantitative data on the changes in stomatal density

LENNY L. R. K OUWENBERG; W OLFRAM; M. K URSCHNER; H ENK V ISSCHER

2004-01-01

133

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

134

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

135

Activity and residues of imidacloprid applied to soil and tree trunks to control hemlock woolly adelgid (Hemiptera: Adelgidae) in forests.  

PubMed

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) Mauget systems. The applications were made in the fall and the following spring. Adelgid populations on the hemlocks (Tsuga spp.) were assessed in the fall of two successive years after the treatments. Relative to the untreated control trees, all the soil applications resulted in population reductions, but none of the trunk injections resulted in reductions. Fall and spring treatment efficacy did not differ. Reductions by the soil treatments were between 50 and 100% (avg 80%) by the first fall and 83-100% (avg 98.5%) by the second fall. Analysis of imidacloprid residues using enzyme-linked immunosorbent assay found residues in sap, needles, and twigs 1 mo to 3-yr after application. A laboratory dose-response bioassay using excised, adelgid-infested hemlock branches with cut ends immersed in serial dilutions of imidacloprid determined the LC50 value to be 300 ppb, based on an exposure of 20 d. A high degree of suppression of the adelgid on forest trees was associated with residues in hemlock tissue > 120 ppb 2 yr after soil treatment. Although precise relationships between residues and efficacy are elusive, it is clear that soil application of imidacloprid resulted in chronic residues of imidacloprid in tissues and suppression of adelgid populations for > 2 yr. PMID:16937680

Cowles, R S; Montgomery, M E; Cheah, C A S J

2006-08-01

136

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

137

Comparison of Soil Geochemistry and Nitrogen Cycling beneath Eastern Hemlock and Black Birch Regrowth Forest, West Whately, MA, U.S.A  

NASA Astrophysics Data System (ADS)

Ecological forest successions associated with introduction of invasive species, human disturbance, and climate change may alter biogeochemical cycles within forested New England watersheds. Spread of the invasive insect hemlock wooly adelgid (Adelges tsungae, HWA) to eastern North America is causing decline and mortality of the eastern hemlock (Tsuga canadensis). To evaluate whether changes in nutrient cycling could be altered by this disturbance, we investigated differences in soil geochemistry in secondary growth forest located at the MacLeish Field Station, Whately, MA, where HWA occurrences recently have been observed. Eastern hemlock on this property was selectively logged 20 years ago, with black birch regrowth succeeding hemlock. We hypothesize that such a succession could repeat should hemlock on the property experience mortality due to the HWA. Between 2010-2011, we measured soil pH, exchangeable acidity (Al3+ and H+), exchangeable base cations (Ca2+, Mg2+, Na+, and K+), and nitrogen mineralization rates of soil cores collected beneath a hemlock stand and beneath an adjacent, younger black birch stand that succeeded hemlock following logging. Although soil pH of organic horizons between hemlock and black birch are both acidic (pH<4.5), the concentration of exchangeable base cations in the organic horizon beneath black birch is approximately 1.5 times higher than hemlock, reflecting its higher total cation exchange capacity. These results suggest that the acidity typically associated with soils that support hemlock forests has not been neutralized by black birch regrowth, and soil acidity may be stabilized by exchangeable Al3+, which is similar for the two sites. More base cations may be becoming available within the cation exchange pool of the black birch soil, possibly reflecting variation in inputs of base cations from throughfall and leaf litter. Net nitrogen mineralization and nitrification rates determined for incubated soil cores, measured between May - July 2011, showed no significant difference between black birch and hemlock tree stands. Percent N mineralization due to nitrification is slightly less than 10%. Both tree stands do show a significant rise in nitrogen mineralization rates between the May-June and June-July incubation periods, primarily due to production of NH4+. Additional data will be presented to assess nitrogen mineralization rates for the remainder of the 2011 growing season.

Rhodes, A. L.; Blanchett, S.; Sweezy, T.; Mansen, S.

2011-12-01

138

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

139

CHANGING LITTER RESOURCES ASSOCIATED WITH HEMLOCK WOOLLY ADELGID INVASION AFFECT BENTHIC COMMUNITIES IN HEADWATER STREAMS.  

E-print Network

??Hemlock woolly adelgid is an invasive herbivore causing extensive mortality of eastern hemlock, an important foundation species that provides stable conditions influencing biological communities. Hemlock… (more)

Strohm, Christopher J

2014-01-01

140

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Flint, Michigan; Application for Subzone; Hemlock Semiconductor Corporation (Polysilicon); Hemlock, MI An application...status for the polysilicon manufacturing facility of Hemlock Semiconductor Corporation (HSC), located in Hemlock, Michigan....

2011-10-12

141

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

142

Restocking with broadleaved species during the conversion of Tsuga heterophylla plantations to native woodland using natural regeneration  

Microsoft Academic Search

The removal of conifers planted during the twentieth century on sites that had been woodland for many centuries, with the\\u000a intention of restoring native broadleaved species, is an important aim of forestry policy in Great Britain. Current guidance\\u000a generally advocates gradual removal of plantation trees using continuous cover silviculture and restocking by natural regeneration,\\u000a but methods are largely untested. This

Ralph Harmer; Geoff Morgan; Kate Beauchamp

2011-01-01

143

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

144

Nutrient concentrations and nitrogen mineralization in forest floors of single species conifer plantations in coastal British Columbia  

Microsoft Academic Search

We examined the extent to which nutrient concentrations and C and N mineralization rates in forests floors under different tree species are predictable from the chemistry of foliar litter and its rate of decomposition. We studied replicated single species plantations of western redcedar ( Thuja plicata Donn ex D. Don), western hemlock (Tsuga heterophylla (Raf.) Sarg.), Douglas-fir (Pseudotsuga menziesii (Mirb.)

C. E. Prescott; L. Vesterdal; J. Pratt; K. H. Venner; L. M. de Montigny; J. A. Trofymow

2000-01-01

145

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

146

Vertical and temporal distribution of insolation in gaps in an old-growth coniferous forest  

Microsoft Academic Search

The combination of canopy access at the Wind River Canopy Crane Research Facility, hemispherical photog- raphy, and long-term insolation data provided estimates of vertical and temporal distributions of insolation in nine can - opy gaps in a 65 m tall Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) - western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest. Yearly insolation (long-term data from Portland, Oreg.)

Stuart B. Weiss

2000-01-01

147

Eleven-year growth response of young conifers to biosolids or nitrogen and phosphorus fertilizer on northern Vancouver Island  

Microsoft Academic Search

To test the hypothesis that fertilization with municipal biosolids causes a larger long-term tree growth response than fertilization with conventional chemical fertilizers, we measured the height and diameter of planted western redcedar (Thuja plicata Donn ex D. Don), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and amabilis fir (Abies amabilis (Dougl.) Forbes) 11 years after fertilization with biosolids or nitrogen and

Cindy E. Prescott; Leandra L. Blevins

2005-01-01

148

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, including two focal plant species, crenulate moonwort and mountain moonwort. Xeric or dry forests

149

The importance of mature conifers to red crossbills in southeast Alaska  

Microsoft Academic Search

Red crossbills (Loxia curvirostra) in southeast Alaska feed mostly on seeds in the cones of western hemlock (Tsuga heterophylla) and Sitka spruce (Picea sitchensis). During a year of poor cone production, red crossbills did not forage in young stands. Within mature stands, crossbills tended to forage preferentially on trees with large cone crops. These favored trees were also the larger

William C Holimon; Craig W Benkman; Mary F Willson

1998-01-01

150

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

151

Landscape vs Gap-level Controls on the Abundance of a Fire-sensitive, Late-successional Tree Species  

Microsoft Academic Search

Tsuga heterophylla (western hemlock), a fire-sensitive, late-successional tree species, is an important component of old-growth forests in the\\u000a Pacific Northwest, USA. In the Oregon Coast Range, however, T. heterophylla occurs at low densities in or is completely absent from many conifer stands. We used a cellular automata-based simulation\\u000a model to explore the influences of the fire regime and gap disturbances

Michael C. Wimberly; Thomas A. Spies

2002-01-01

152

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

USGS Publications Warehouse

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

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

2009-01-01

153

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

154

Plant, Cell and Environment (2006) 29, 105114 2006 Blackwell Publishing Ltd 105  

E-print Network

species Pseudotsuga menziesii (Mirb.) Franco and Tsuga heterophylla (Raf.) Sarg. The trees used- and vessel- bearing species. Key-words: Pseudotsuga menziesii; Tsuga heterophylla; capacitance; sap velocity

Lachenbruch, Barbara

155

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

156

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

PubMed

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

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

2007-06-01

157

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Authority for Subzone Status, Hemlock Semiconductor, L.L.C., (Polysilicon), Clarksville...polysilicon manufacturing facility of Hemlock Semiconductor, L.L.C., located in Clarksville...polysilicon at the facility of Hemlock Semiconductor, L.L.C., located in...

2013-04-09

158

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

159

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

160

Host Plant Associations of an Entomopathogenic Variety of the Fungus, Colletotrichum acutatum, Recovered from the Elongate Hemlock Scale, Fiorinia externa  

PubMed Central

A fungal epizootic has been detected in populations of the scale Fiorinia externa Ferris (Hemiptera: Diaspididae) in the eastern hemlock, Tsuga canadensis (L.) Carrière (Pinales: Pinaceae), of several northeastern states. Colletotrichum acutatum Simmonds var. fioriniae Marcelino and Gouli var. nov. inedit (Phyllachorales: Phyllachoraceae), a well-known plant pathogen, was the most commonly recovered fungus from these infected scales. This is the second report of a Colletotrichum sp. infecting scale insects. In Brazil C. gloeosporioides f. sp. ortheziidae recovered from Orthezia praelonga is under development as a biopesticide for citrus production. C. acutatum was detected growing endophytically in 28 species of plants within the epizootic areas. DNA sequences of the High Mobility Box at the MAT 1–2, mating type gene indicate that Colletotrichum sp. isolates recovered from scale insects and plants within epizootic areas were identical. Results from plant bioassays showed that this entomopathogenic Colletotrichum variety grew endophytically in all of the plants tested without causing external symptoms or signs of infection, with the exception of strawberry plants where mild symptoms of infection were observed. The implications of these findings with respect to the use of this fungus as a biological control agent are discussed. PMID:19613851

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

2009-01-01

161

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

162

Effects of shade on morphology, chlorophyll concentration, and chlorophyll fluorescence of four Pacific Northwest conifer species  

Microsoft Academic Search

Four species of Pacific Northwestconifer seedlings (ponderosa pine [Pinusponderosa Dougl. ex Laws.], Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco], westernredcedar [Thuja plicata Donn ex D. Donn], andwestern hemlock [Tsuga heterophylla (Raf.)Sarg.]) were planted in individual pots and grownunder shade-cloth shelters that provided four levelsof shade (0% [full sunlight], 35%, 55%, and 75%)for approximately 30 weeks. Height growth wasrecorded every 2 weeks. Initial

ShafiqurRehiman Khan; Robin Rose; Diane L. Haase; Thomas E. Sabin

2000-01-01

163

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

164

Effects of the Hemlock Woolly Adelgid on Nitrogen Losses from  

E-print Network

Effects of the Hemlock Woolly Adelgid on Nitrogen Losses from Urban and Rural Northern Forest, Massachusetts 02215, USA ABSTRACT The objectives of this study were to quantify rates of nitrogen inputs to the forest floor, determine rates of nitrogen losses via leaching and to partition the sources of NO3 - from

Templer, Pamela

165

Spatial dependency of soil nutrient availability and microbial properties in a mixed forest of Tsuga heterophylla and Pseudotsuga menziesii, in coastal British Columbia, Canada  

Microsoft Academic Search

Spatial variations in nutrient concentrations and turnover may contribute to variations in productivity within forest ecosystems and be responsible for creating and maintaining diversity of plant species. The aim of this study was to relate spatial patterns in soil nutrient availability and microbial properties in the forest floor and mineral soil in order to explore the controls on variations in

Per Bengtson; Nathan Basiliko; Cindy E. Prescott; Susan J. Grayston

2007-01-01

166

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

E-print Network

??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… (more)

Marias, Danielle E.

2013-01-01

167

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 ...

168

Effects of Triterpenoid-Rich Extracts of Ganoderma tsugae on Airway Hyperreactivity and Th2 Responses in vivo  

Microsoft Academic Search

Background: Airway inflammation and Th2 responses play central roles in allergic asthma. We have previously reported that Ganoderma tsugae supplementation could attenuate airway inflammation in the murine model. Since it remains unclear which part of the G. tsugae exerts this effect on allergic asthma in vivo, this study was meant to investigate if triterpenoid extracts have anti-inflammatory effects on airway

Miaw-Ling Chen; Bi-Fong Lin

2007-01-01

169

[A research on fast-propagation of Pseudostellaria heterophylla].  

PubMed

The result of fast-propagation of Pseudostellaria heterophylla by tissue culture showed that the best explant was stem tip. It also showed the suitable inducement mediums were MS + 6-BA 2.0 mg/L + NAA 0.2 mg/L or MS + 6-BA 4.0 mg/L + NAA 0.4 mg/L for the clustered bud, MS + 2,4-D 4.0 mg/L + Kt 0.5 mg/L or MS + 2,4-D 3.0 mg/L + Kt 0.5 mg/L for the callus growth and 1/2 MS + NAA 0.3 mg/L for the root growth. PMID:12795214

Tan, Xianhe; Chao, Jianguo; Zhang, Yu; Zhang, Ying

2003-02-01

170

Maytenus heterophylla and Maytenus senegalensis, two traditional herbal medicines  

PubMed Central

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

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

2011-01-01

171

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

172

Antitumor activity of polysaccharides isolated from Patrinia heterophylla.  

PubMed

The research investigated the effect of Patrinia heterophylla Bunge (Valerianaceae) polysaccharides (PHB-P1) on U14-bearing mice. The tumor weight of mice treated with PHB-P1 (30, 60 mg/kg body weight) was significantly lower than that of the control group, a decrease of serum lactate dehydrogenase (LDH) activity was observed, and the serum alkaline phosphatase (AKP) level was increased slightly. The number of apoptotic tumor cells was significantly increased in the mice by treatment of PHB-P1 (30, 60 mg/kgbw). Cell cycle analysis showed the accumulation of tumor cells in the G2/M phase and a relative decrease of the S phase. By the immunohistochemical analysis, PHB-P1 (30, 60 mg/kgbw) might up-regulate the expression of p53 and Bax, and significantly inhibited the expression of Bcl-2 in tumor tissues. In conclusion, PHB-P1 could inhibit tumor growth and induce tumor cell apoptosis. PMID:20731553

Lu, Wen-Zong; Geng, Guo-Xia; Li, Qing-Wang; Li, Jian; Liu, Fu-Zhu; Han, Zeng-Sheng

2010-09-01

173

A 9000-year fire history from the Oregon Coast Range, based on a high-resolution charcoal  

E-print Network

plicata Donn ex D. Don, Tsuga heterophylla (Raf.) Sarg., and Picea sitchensis (Bong.) Carr., increased espèces sensibles au feu, comme le Thuja plicata Donn ex D. Don, le Tsuga heterophylla (Raf.) Sarg. et le

Whitlock, Cathy L.

174

Crown conductance and tree and stand transpiration in a second-growth Abies amabilis  

E-print Network

. ex J. Forbes ­ Tsuga heterophylla (Raf.) Sarg. forest in western Washington, U.S.A. We calculated'arbres entiers dans une forêt de Abies amabilis (Dougl. ex Loud.) Dougl. ex J. Forbes et de Tsuga heterophylla

Martin, Timothy

175

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

176

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.

177

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.

178

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

E-print Network

, horses, swine, sheep, goats, dogs, and people when ingested. The plant produces volatile alkaloids be small, so it is important not to let animals graze or feed on poison hemlock. In the case of horses, 4

Ginzel, Matthew

179

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

Federal Register 2010, 2011, 2012, 2013, 2014

...for use as a biological control agent to reduce the severity...for use as a biological control agent to reduce the severity...insect pest destructive to forest and ornamental hemlock...management options include chemical control and silvicultural...

2010-05-20

180

Lobaria pulmonaria abundance as an indicator of macrolichen diversity in Interior CedarHemlock  

E-print Network

Lobaria pulmonaria abundance as an indicator of macrolichen diversity in Interior Cedar supported more species than young or mature forests. The abundance of Lobaria pulmonaria (L.) Hoffm words: macrolichen diversity, Interior Cedar­Hemlock zone, Lobaria pulmonaria, indicator species

Northern British Columbia, University of

181

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

182

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

183

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 of needle length, decreased significantly with increasing CO2. For Tsuga heterophylla, the stomatal with a high preservation capacity, fossil needles of Tsuga heterophylla, Picea glauca, P. mariana, and Larix

Cochran-Stafira, D. Liane

184

Four aristolochic acid esters of rearranged ent-elemane sesquiterpenes from aristolochia heterophylla  

PubMed

Four aristolochic acid esters of ent-elemane type sesquiterpene having a new carbon skeleton, aristophyllides A (1), B (2), C (3), and D (4), were isolated from the stems and roots of Aristolochia heterophylla. The esters were characterized by NMR and MS methods and included is a study of absolute configurations using the CD exciton chirality method. PMID:10075784

Wu; Chan; Leu; Wu; Li; Mori

1999-02-01

185

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

186

Water hemlock (Cicuta douglasii) toxicoses in sheep: pathologic description and prevention of lesions and death.  

PubMed

Water hemlock causes numerous livestock losses in North America every year. Description of pathologic and serum biochemical changes has been lacking in the literature. Tubers of western water hemlock (Cicuta douglasii) induced excessive salivation, tremors, grand mal seizures, skeletal and cardiac myodegeneration, and death in sheep given 1.2-2.7 g fresh tuber/kg body weight by gavage. Seizures were intermittent with periods of relaxation until death occurred from anoxia during seizure activity. In sheep given 1.5-2.5 times the lethal dose of water hemlock by gavage, intravenous administration of sodium pentobarbital at the onset of the first seizure prevented further seizure activity and skeletal and cardiac myodegeneration and resulted in rapid and complete recovery. PMID:8953535

Panter, K E; Baker, D C; Kechele, P O

1996-10-01

187

Sesquiterpene esters of aristolochic acid from the root and stem of Aristolochia heterophylla.  

PubMed

Three novel sesquiterpene esters of aristolochic acid, aristoloterpenate-II (2), -III (3), and-IV (4), together with known aristoloterpenate-I (1), were isolated and characterized from the root and stem of Aristolochia heterophylla. Their structures were elucidated by spectroscopic methods. The absolute configuration of these compounds at C-4' was determined as R by circular dichroic studies. These compounds showed cytotoxicity against hepatoma G2, 2, 2, 15 cells. PMID:10096848

Wu, T S; Chan, Y Y; Leu, Y L; Chen, Z T

1999-03-01

188

Structure elucidation of compounds extracted from the Chinese medicinal plant Patrinia heterophylla  

Microsoft Academic Search

For several hundred years, Patrinia heterophylla has been used in traditional Chinese medicine as a treatment for abscesses, hepatitis, tonsillitis, ulcers, etc. Recent research suggests that it may also have some anti-cancer activity. We have extracted five pure compounds from this plant; two known flavonols without bio-activity, one known isocoumarin glucoside that exhibits some cytotoxic activity toward HeLa cervical cancer

X. Lu; D. Li; N. K. Dalley; S. G. Wood; N. L. Owen

2007-01-01

189

Two new cytotoxic iridoid esters from the rhizomes and roots of Patrinia heterophylla Bunge.  

PubMed

Two new iridoid esters, named patriheterdoid B, C, have been isolated from the rhizomes and roots of Patrinia heterophylla Bunge. Their structures were elucidated by extensive spectroscopic technologies. Together with patriheterdoid B, C, two known analogues have been isolated and identified by means of mass spectrometry and (1)H and (13)C NMR spectrometry. These compounds showed cytotoxic activity against SGC-7901, PC3 cell lines. PMID:23639075

Yang, Bo; Cheng, Ru-Bin; Wang, Yi-Qi; Shen, Li; Zhang, Ru-Song

2013-01-01

190

Structure elucidation of compounds extracted from the Chinese medicinal plant Patrinia heterophylla.  

PubMed

For several hundred years, Patrinia heterophylla has been used in traditional Chinese medicine as a treatment for abscesses, hepatitis, tonsillitis, ulcers, etc. Recent research suggests that it may also have some anti-cancer activity. We have extracted five pure compounds from this plant; two known flavonols without bio-activity, one known isocoumarin glucoside that exhibits some cytotoxic activity toward HeLa cervical cancer cells, and two novel compounds that show considerable cytotoxic activity toward HeLa cells. PMID:17616894

Lu, X; Li, D; Dalley, N K; Wood, S G; Owen, N L

2007-07-10

191

[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

192

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

193

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

194

Proteomic analysis of the effect of triterpenes from Patrinia heterophylla on leukemia K562 cells.  

PubMed

For centuries, Patrinia heterophylla had been used in China to treat many diseases including tumor. Triterpenes has been identified as the major active constituents in Patrinia heterophylla. To elucidate the antitumor mechanism of triterpenes from Patrinia heterophylla1 (TPH), a proteomic analysis is carried out with TPH treatment in K562 cells. The total proteins extracted from TPH treated K562 cells are analyzed by two dimensional gel electrophoresis (2-DE) and compared with those untreated K562 cells. Mass spectrometry is applied to identify the differentially expressed proteins. Twenty-three differentially expressed significant proteins are discovered. Eight proteins are later identified by mass spectrometry (MALDI-TOF-MS) and Mascot software. Among them, four proteins are up-regulated (Aldolase A, Glyceraldehyde-3-phosphate dehydrogenase, Flavin reductase and Hemoglobin subunit) and four proteins were down-regulated (Heat-shock protein 90 ?Alpha? (HSP90-?Alpha?), Eukaryotic translation initiation factor 5A, Moesin, tublin) by TPH treatment in K562 cells. The identified proteins are associated with energy metabolism, oxidative stress, apoptosis, signal transduction, differential induction, and protein biosynthesis. These findings might provide valuable insights into the antitumor mechanism of TPH in K562 cells. PMID:23064283

Wei, Dong-Feng; Wei, Yan-Xia; Cheng, Wei-Dong; Yan, Ming-Fei; Su, Gang; Hu, Yan; Ma, Ya-Qiong; Han, Chao; Lu, Yan; Hui-Ming, Cao; Bao, Ying-Cun

2012-12-18

195

Fingerprint chromatogram analysis of Pseudostellaria heterophylla (Miq.) Pax root by high performance liquid chromatography.  

PubMed

A simple and reliable high performance liquid chromatographic (HPLC) method has been developed and validated for the fingerprinting of extracts from the root of Pseudostellaria heterophylla (Miq.) Pax. HPLC with gradient elution was performed on an authentic reference standard of powdered P. heterophylla (Miq.) Pax root and 11 plant samples of the root were collected from different geographic locations. The HPLC chromatograms have been standardized through the selection and identification of reference peaks and the normalization of retention times and peak intensities of all the common peaks. The standardized HPLC fingerprints show high stability and reproducibility, and thus can be used effectively for the screening analysis or quality assessment of the root or its derived products. Similarity index calculations based on cosine angle values or correlation methods have been performed on the HPLC fingerprints. As a group, the fingerprints of the P. heterophylla (Miq.) Pax samples studied are highly correlated with closely similar fingerprints. Within the group, the samples can be further divided into subgroups based on hierarchical clustering analysis (HCA). Sample grouping based on HCA coincides nicely with those based on the geographical origins of the samples. The HPLC fingerprinting techniques thus have high potential in authentication or source-tracing types of applications. PMID:17069250

Han, Chao; Chen, Junhui; Chen, Bo; Lee, Frank Sen-Chun; Wang, Xiaoru

2006-09-01

196

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

197

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

E-print Network

Poison hemlock, Conium maculatum, (Figure 1) is a member of the plant family Apiaceae, which plant, prob- ably during the 1800s. It is now widely distributed in the western United States plant com- munities in riparian woodlands, flood- plains of natural aquatic systems, and grazing areas

Ishida, Yuko

198

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

199

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

200

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

PubMed

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

Miyauchi, Teruhisa; Mori, Mitsunori; Ito, Katsuhiko

2005-01-21

201

Ecology, 95(8), 2014, pp. 20472054 2014 by the Ecological Society of America  

E-print Network

for the dominant late- successional species, Tsuga heterophylla. The long-lived, early-seral Pseudotsuga menziesii mortality; Tsuga heterophylla; Wind River Forest Dynamics Plot. INTRODUCTION Detecting and understanding tree mortality and ingrowth maintain equilibrium pattern in an old-growth Pseudotsuga­Tsuga forest

Chen, Jiquan

202

Late Quaternary vegetation and climate history near Little Lake, central Coast Range, Oregon  

E-print Network

of Lake Creek (Orr et al., 1992; Lane, 1988). This site lies within the Tsuga heterophylla Zone (Franklin and common names). In western Oregon, the Tsuga heterophylla Zone ranges in elevation from 150 to 1000 m, the Tsuga het- erophylla Zone includes Noble fir and Pacific silver fir. East of the Coast Range

Whitlock, Cathy L.

203

Gaps and Soil C Dynamics in Old Growth Northern Hardwood–Hemlock Forests  

Microsoft Academic Search

Old growth forest soils are large C reservoirs, but the impacts of tree-fall gaps on soil C in these forests are not well\\u000a understood. The effects of forest gaps on soil C dynamics in old growth northern hardwood–hemlock forests in the upper Great\\u000a Lakes region, USA, were assessed from measurements of litter and soil C stocks, surface C efflux, and

B. C. Scharenbroch; J. G. Bockheim

2008-01-01

204

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

205

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

206

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

207

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

SciTech Connect

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

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

1993-01-01

208

Harvesting Overstocked Stands of Small Diameter Trees : Stem Densities of Trees from Overstocked Mixed Conifer Stands of Western Hemlock, Douglas-Fir and Western Redcedar. [Hemlocks  

SciTech Connect

Stem density (wood and bark combined) on overstocked mixed conifer stands of Douglas-fir, westernn hemlock and wester redcedar was studied in the Quilcene Ranger District, Olympic National Forest in the State of Washington. This study was to better understand the economics, technology, and impacts of harvesting overstocked stands of small diameter timber. Previous studies on the density of stem wood that generally have been derived from trees growing in stands of normal stocking levels. Stem densities, an essential parameter in the determination of stem biomass, has not previously 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 reliability. Thus the need to specifically examine stem densities in trees grown under these adverse conditions exists. 3 tabs.

Pong, W.Y.; Waddell, Dale R.

1985-03-15

209

Evolution du rapport C/N dans les feuilles et au cours de la dcomposition des litires  

E-print Network

, et quelques conifères : Pseudot.suga menzie.sü, Picea abies, Picea sitchen.sis, Tsuga heterophylla, Picea abies et Tsuga heterophylla), soit au lieu-dit le Bois-Robert, à quelques kilomètres au sud accusée se manifeste dans les reboisements de Picea abies et de Tsuga heterophylla par la présence d

Paris-Sud XI, Université de

210

Bryophyte Species Associations with Coarse Woody Debris and Stand Ages in Oregon Author(s): Thomas R. Rambo and Patricia S. Muir  

E-print Network

incorporated litterfall, to substrate and stand age in Pseudotsuga menziesii-Tsuga heterophylla stands at two as reservoirs of biodiversity in Tsuga het- erophylla zone forests (Franklin & Dyrness 1973) of the Pacific

North, Malcolm

211

Printed from the CJO service for personal use only by... New Phytol. (1999), 142, 355370  

E-print Network

isolates representing 20 species of Rhizopogon on three conifer species (Pseudotsuga menziesii, Tsuga heterophylla, and Pinus contorta). Section Villosuli was almost exclusively ectomycorrhizal with Pseudotsuga & Trappe, 1994). In Pacific Northwest forests dominated by Pseudo- tsuga menziesii (Douglas fir), several

Massicotte, Hugues

212

Postglacial vegetation and climate dynamics in the Seymour-Belize Inlet Complex, central  

E-print Network

and a successional mosaic of Tsuga heterophylla and Alnus occurred at Tiny Lake. Climate cooling and moistening at 8740 Ã? 70 14 C a BP initiated the development of closed, late successional T. heterophylla

Patterson, Timothy

213

Occurrence of ectomycorrhizae on ericaceous and coniferous seedlings grown in soils from the Oregon Coast Range.  

E-print Network

??Seedlings of Gaultheria shallon, Pseudotsuga menziesii, Rhododendron macrophyllum and Tsuga heterophylla were grown together in the greenhouse in soils from three young managed Douglas-fir forests… (more)

Smith, Jane E. (Jane Elizabeth)

1993-01-01

214

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

215

Journal of the Torrey Botanical Society 131(3), 2004, pp. 220231 Ecological species groups of South Carolina's Jocassee  

E-print Network

Rhododendron group (typified by Rhododendron maximum, Mitchella repens, and Hexastylis heterophylla). Tree groups ranged from a Quercus coccinea group to a Tsuga canadensis group. Consistent with previous

Abella, Scott R.

216

United States Department of  

E-print Network

, Libocedrus decurrens, Picea sitchensis, Pseudotsuga menziesii var. menziesii, Thuja plicata, Tsuga heterophylla The Authors James L. Jenkinson is research plant physiologist, Institute of Forest Genetics

Standiford, Richard B.

217

POPULATION ECOLOGY Influence of Plant Community Structure on Natural Enemies of  

E-print Network

Aphelinidae, Aphytis, Chionaspis heterophyllae, habitat effects, natural enemies, conservation biological, including species in the Pinaceae (Abies, Picea, Pinus, Pseudot- suga, and Tsuga), Cupressaceae (Juniperus

Hanks, Lawrence M.

218

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

PubMed Central

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

219

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; temperature; tree growth; Tsuga mertensiana. INTRODUCTION Global mean temperatures may rise 1 ­3 C over

Wallin, David O.

220

Effects of an introduced pathogen on resistance to natural disturbance: beech bark disease and  

E-print Network

(Betula alleghaniensis Britt.) and eastern hemlock (Tsuga canadensis (L.) Carr.) increased in basal area les espèces comme le bouleau jaune (Betula alleghaniensis Britt.) et la pruche du Canada (Tsuga

221

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.

222

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

223

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

Microsoft Academic Search

Summary 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 utiliza- tion in a 450-year-old Pseudotsuga menziesii (Mirb.) Franco- -Tsuga hetei~phylla (Raf.} Sarg. forest in southwestern Wash- ington State. Soil volumetric water content (8) was continu-

FREDERICK C. MEINZER; JEFFREY M. WARREN; J. RENEE BROOKS

224

Impacts of forest gaps on soil properties and processes in old growth northern hardwood-hemlock forests  

Microsoft Academic Search

We examined the influence of treefall gaps on soil properties and processes in old growth northern hardwood-hemlock forests\\u000a in the upper Great Lakes region, USA. We found significantly greater solar radiation, soil moisture contents and soil temperatures\\u000a in gaps compared to adjacent closed canopy plots. Gaps had significantly less exchangeable base cations (K, Ca, and Mg) compared\\u000a to forest plots

B. C. Scharenbroch; J. G. Bockheim

2007-01-01

225

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

Microsoft Academic Search

Summary 1 Tree populations were monitored for six decades on a grid of 140 permanent plots in old-growth mesic (hemlock-northern hardwood) forests in northern Michigan, USA. Multiple remeasurements allow assessment of stability of late-suc- cessional forests and analysis of spatial patterns and environmental linkages. 2 This forest is not compositionally stable. Betula alleghaniensis has declined with little regeneration, suggesting dependence

Kerry D. Woods

2000-01-01

226

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

227

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

228

Characterization of a polysaccharide–protein complex from Ganoderma tsugae mycelium by size-exclusion chromatography combined with laser light scattering  

Microsoft Academic Search

A water-soluble polysaccharide–protein complex (GM3) extracted from the mycelium of Ganoderma tsugae was characterized using size-exclusion chromatography combined with laser light scattering (SEC-LLS). Two peaks coded as fractions I and II appeared in the SEC pattern of GM3 in 0.5 M NaCl aqueous solution, corresponding to the weight-average molecular mass (Mw) of 355×104 and 6.3×104, respectively. The relationship between the

Yanfei Peng; Lina Zhang

2003-01-01

229

Physiological specialization of Heterobasidion annosum on conifer hosts TOMHSIANGAND R. L. EDMONDS  

E-print Network

analyse pratiquCe sur quatre arbres de l'espbce Tsuga heterophylla i l'aide de cinq isolats donne les m rather than to dif- ferences between the pathogen isolates. A second analysis involving four Tsuga heterophylla trees and five isolates showed similar results. In both the interspecific analysis with eight

Hsiang, Tom

230

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 plicataSpatial Relationship of Biomass and Species Distribution in an Old-Growth Pseudotsuga-Tsuga Forest characterized by high proportions of T. heterophylla and T. plicata depending on spatial locations across

Song, Bo

231

A record of Lateglacial and Holocene vegetation and climate change from Woods Lake, Seymour Inlet, coastal British Columbia, Canada  

E-print Network

-Holocene as indicated by the dominance of Cupressaceae, Tsuga heterophylla, Alnus and Picea in the forest around forest with Tsuga species, Picea and Abies and slightly warmer conditions and increased moisture. Alnus the study site. This represented a transitional stage to the late-Holocene Cupressaceae­T. heterophylla

Patterson, Timothy

232

Polysaccharide-degrading complex produced in wood and in liquid media by the brown-rot fungus Poria placenta  

SciTech Connect

P.placenda produced the same type of enzyme activities when grown in liquid culture with simple sugars, hemlock (Tsuga heterophylla), or Liquidambar styraciflua sawdust and inoculated in decayed L. styraciflua blocks. However, there were differences in amounts of enzyme activity produced per mg of protein from decayed wood and liquid media; beta-, alpha-galactosidase, and xylanase activities were higher in liquid culture than in extracts from decayed wood, while beta-xylosidase activities were slightly higher in extracts than in liquid culture. Despite these quantitative differences, the extracellular carbohydrolase complex from liquid culture must be structurally similar to that of decayed wood because of similar isoelectric points and electrophoretic and molecular sieving properties.

Highley, T.L.; Wolter, K.E.; Evans, F.J.

1981-01-01

233

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

234

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

235

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.

236

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

237

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

USGS Publications Warehouse

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

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

2002-01-01

238

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

239

Proceedings: Symposium on Sustainable Management of Hemlock Ecosystems in Eastern North America GTR-NE-267 High resolution paleoecological analyses from Shepherd  

E-print Network

fossil pollen analysis the impact of these droughts on the upland forest is poorly visible, except results imply drought- weakened hemlock trees and stands, and that drought may have triggered local insect beauty and an important cultural value for humans. However, in the past few years an increasing number

McAndrews, John H.

240

A Split G-Quadruplex and Graphene Oxide-Based Low-Background Platform for Fluorescence Authentication of Pseudostellaria heterophylla  

PubMed Central

A label-free split G-quadruplex and graphene oxide (GO)-based fluorescence platform has been designed to distinguish Pseudostellaria heterophylla (PH) from its adulterants based on the differences in their nrDNA ITS sequences. Herein, GO has been first introduced to capture G-rich probes with 2:2 split mode and then decrease the background signal. As T-DNA exists, the probes leave the GO surface to form double-stranded structures followed by the formation of the overhanging G-rich sequence into a G-quadruplex structure, which combines quinaldine red specifically to produce a strong fluorescence signal. In addition, this strategy allows detection of T-DNA in a wide range of concentrations from 1.0 × 10?8 to 2.0 × 10?6 mol·L?1 with a detection limit of 7.8 × 10?9 mol·L?1. We hope that the split G-quadruplex/GO platform can be utilized to further develop gene identification sensors in Traditional Chinese Medicine or other analysis areas. PMID:25479327

Zheng, Zhenzhu; Hu, Juan; He, Zhaodong

2014-01-01

241

Effects of elevated nitrogen dioxide and carbon dioxide on the growth of Sugar Maple and Hemlock seedlings  

NASA Astrophysics Data System (ADS)

The partial pressure of nitrogen dioxide (NO2) in the earth's atmosphere has been rising since the industrial revolution and is likely to continue rising due to the burning of fossil fuels. When NO2 enters plant leaves, it can undergo reactions that produce nitrate, which can be a source of nutrient nitrogen for the plant. However, NO2 is also an oxidant with the potential to damage cell membranes and decrease growth. The goals of this study were to examine the effect of NO2 on plant productivity alone and in combination with elevated CO2 under both nitrogen- and non-nitrogen-limiting conditions. To assess these effects, we conducted CO2, NO2, and CO2 + NO2 fumigations of sugar maple and eastern hemlock seedlings in open-topped chambers and measured relative growth rate, specific leaf area, root:shoot, and C:N of the leaves, stems, and roots. Sugar maple growth was reduced by 7% under elevated NO2 when nitrogen was limiting. When nitrogen was not limiting and CO2 was ambient, elevated NO2 caused a 4% decrease in growth and when CO2 was elevated there was no growth effect. Hemlock growth was increased by elevated NO2 regardless of nitrogen status and under both partial pressures of CO2; 3 and 8% increase in growth under ambient and elevated CO2, respectively. These data suggest gaseous reactive nitrogen may augment or decrease the future growth effects of elevated CO2 depending on plant species identity. In addition, perhaps because of differences in nitrogen metabolism and physiology, deciduous and evergreen tree species appear to have different responses to reactive nitrogen fumigation. These results underscore the need for examining the responses of vegetation to mixtures of gases representative of the future atmosphere rather than examining the influence of carbon dioxide alone.

Eller, A. S.; McGuire, K. L.; Sparks, J. P.

2005-12-01

242

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

243

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

244

Lobaria pulmonaria abundance as an indicator of macrolichen diversity in Interior Cedar–Hemlock forests of east-central British Columbia  

Microsoft Academic Search

Orographic precipitation over interior mountains has resulted in the formation of the inland temperate rain- forest, where certain stands are potentially antique and support a rich flora of epiphytic macrolichens. We documented macrolichen diversity across three age-classes in forests of the Interior Cedar-Hemlock biogeoclimatic zone (i.e., ICHwk3 subzone) east of Prince George, British Columbia. Our objectives were to report changes

Jocelyn Campbell; Arthur L. Fredeen

2004-01-01

245

Mycorrhizal effects on potassium fluxes by northwest coniferous seedlings.  

PubMed

In ectomycorrhizae, the relative abilities of mycobiont and host plant to take up and store inorganic nutrients are not easily determined due to the intimate physical relationship of the two components forming the association. Since compartmental analysis of solute elution can estimate cellular compartment pool sizes and unidirectional fluxes across membranes, we have used this method to study ectomycorrhizal coniferous roots. Rubidium-86, used as a tracer for potassium, was loaded into and eluted from intact roots of nonmycorrhizal and mycorrhizal (with the fungus Hebeloma crustuliniformme [Bull.: St. Amans Quél] Douglas fir (Pseudotsuga menziesii [Mirb.] Franco), western hemlock (Tsuga heterophylla [Raf.] Sarg.) and Sitka spruce (Picea sitchensis [Bong.] Carr.) seedlings.Mycorrhizas significantly increased (86)Rb uptake rates while decreasing the amount of (86)Rb released to the external solution. Using compartmental analysis, the flux data suggest that the primary mycorrhizal effects were to increase inward potassium fluxes across the fungal tonoplast and to decrease potassium efflux across the fungal tonoplast, as compared with nonmycorrhizal seedling roots. The result was greater potassium storage, presumably in the fungal vacuole. The three coniferous species responded differently to fungal infection with respect to potassium fluxes. Both cytoplasmic and vacuolar fluxes for mycorrhizal hemlock were 2-fold greater than for spruce and 3-fold greater than for Douglas fir. These results demonstrate the usefulness of compartmental analysis for study of ion fluxes in intact mycorrhizal root systems and suggest that the fungal tonoplast may be the site for regulation of potassium fluxes in these coniferous roots. PMID:16663971

Rygiewicz, P T; Bledsoe, C S

1984-12-01

246

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

PubMed

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

Miyauchi, Teruhisa; Mori, Mitsunori; Ito, Katsuhiko

2005-11-18

247

Mycorrhizal Effects on Potassium Fluxes by Northwest Coniferous Seedlings 1  

PubMed Central

In ectomycorrhizae, the relative abilities of mycobiont and host plant to take up and store inorganic nutrients are not easily determined due to the intimate physical relationship of the two components forming the association. Since compartmental analysis of solute elution can estimate cellular compartment pool sizes and unidirectional fluxes across membranes, we have used this method to study ectomycorrhizal coniferous roots. Rubidium-86, used as a tracer for potassium, was loaded into and eluted from intact roots of nonmycorrhizal and mycorrhizal (with the fungus Hebeloma crustuliniformme [Bull.: St. Amans Quél] Douglas fir (Pseudotsuga menziesii [Mirb.] Franco), western hemlock (Tsuga heterophylla [Raf.] Sarg.) and Sitka spruce (Picea sitchensis [Bong.] Carr.) seedlings. Mycorrhizas significantly increased 86Rb uptake rates while decreasing the amount of 86Rb released to the external solution. Using compartmental analysis, the flux data suggest that the primary mycorrhizal effects were to increase inward potassium fluxes across the fungal tonoplast and to decrease potassium efflux across the fungal tonoplast, as compared with nonmycorrhizal seedling roots. The result was greater potassium storage, presumably in the fungal vacuole. The three coniferous species responded differently to fungal infection with respect to potassium fluxes. Both cytoplasmic and vacuolar fluxes for mycorrhizal hemlock were 2-fold greater than for spruce and 3-fold greater than for Douglas fir. These results demonstrate the usefulness of compartmental analysis for study of ion fluxes in intact mycorrhizal root systems and suggest that the fungal tonoplast may be the site for regulation of potassium fluxes in these coniferous roots. PMID:16663971

Rygiewicz, Paul T.; Bledsoe, Caroline S.

1984-01-01

248

Patterns of primary succession on the foreland of Coleman Glacier, Washington, USA  

E-print Network

canopy of the deciduous shrub Alnus viridis followed by a dense canopy of Abies amabilis, Tsuga heterophylla, and Pseudotsuga menziesii. Introduction Due to a significant increase in human distur- bances

del Moral, Roger

249

Application of free selection in mixed forests of the inland northwestern United States  

E-print Network

in both the moist (Thuja plicata Donn. ex D. Don, Abies grandis (Dougl. ex D. Don) Lindl., Tsuga heterophylla [Raf.] Sarg.) forests of northern Idaho to reduce the risk of wildfire damaging historical

Fried, Jeremy S.

250

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

NASA Astrophysics Data System (ADS)

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

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

251

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

252

101Northwest Science, Vol. 83, No. 2, 2009 2009 by the Northwest Scientific Association. All rights reserved.  

E-print Network

were woody plants and included mountain hemlock (Tsuga mertensiana), white mountain-heather (Cassiope mertensiana) and subalpine fir (Abies lasiocarpa) in order of cover percentage. Thirty-nine vascular plant

Smith, Dan

253

Simulating Historic Landscape Patterns of Fire in the Southern Appalachian Mountains: Implications for Fire History and Management  

E-print Network

), sugar maple (Acer saccharum), black cherry (Prunus serotina), white pine (Pinus strobus), hemlock (Tsuga), beech (Fagus spp.), birch (Betula spp.), sassafras (Sassafras albidum), tulip poplar (Liriodendron tulipifera), and black gum (Nyssa sylvatica...

Gass, Ellen R

2014-05-21

254

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

255

ORIGINAL PAPER Multi-proxy evidence of postglacial climate  

E-print Network

allowed Pseudotsuga menziesii to migrate northward to this site where it grew with Picea, Tsuga heterophylla and Alnus. The climate became cooler and moister at ca. 8,000 yr BP (ca. 9,200 cal. yr BP temperate rainforest domi- nated by Cupressaceae and T. heterophylla. This was associated with progressive

Patterson, Timothy

256

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

257

Base-cation Cycling by Individual Tree Species in Old-growth Forests of Upper Michigan, USA  

Microsoft Academic Search

The influence of individual tree species on base-cation (Ca, Mg, K, Na) distribution and cycling was examined in sugar maple (Acer saccharum Marsh.), basswood (Tilia americana L.), and hemlock (Tsuga canadensis L.) in old-growth northern hardwood – hemlock forests on a sandy, mixed, frigid, Typic Haplorthod over two growing seasons in northwestern Michigan. Base cations in biomass, forest floor, and

Ryo Fujinuma; James Bockheim; Nick Balster

2005-01-01

258

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

259

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

260

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

261

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

262

Spatial analysis of within-population microsatellite variability reveals restricted gene flow in the Pacific golden chanterelle (Cantharellus formosus).  

PubMed

We examined the within-population genetic structure of the Pacific golden chanterelle (Cantharellus formosus) in a 50 y old forest stand dominated by Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) with spatial autocorrelation analysis. We tested the null hypothesis that multilocus genotypes possessed by chanterelle genets were randomly distributed within the study area. Fruit bodies from 203 C. formosus genets were collected from a 50 ha study plot. One hundred six unique multilocus genotypes were identified after scoring these collections at five microsatellite loci. Statistically significant positive spatial autocorrelation was detected indicating the presence of fine-scale genetic structure within the area. Repeated autocorrelation analyses with varied minimum distance classes (50-500 m) detected positive spatial genetic structure up to 400 m. Therefore nonrandom evolutionary processes (e.g., isolation by distance) can cause fine-scale genetic structure in C. formosus. The implications of this research for future broad-scale population studies of this species are that population samples should be separated by at least 400 m to be considered statistically independent. Sampling designs that account for fine-scale genetic structure will better characterize heterogeneity distributed across the landscape by avoiding the effects of pseudo replication. PMID:16894970

Dunham, Susie M; O'Dell, Thomas E; Molina, Randy

2006-01-01

263

A novel extractant for removal of hazardous metals from preservative-treated wood waste.  

PubMed

The purpose of this study was to develop a one-step metal extraction 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) preservative. In addition, we tested this method for wood treated with other copper-based preservatives such as ammoniacal copper quaternary (ACQ) and copper, boron, and azole (CuAz). A bioxalate solution consisting of 0.125 M oxalic acid adjusted to pH 3.2 with sodium hydroxide was tested for its ability to extract chromium, copper, and arsenic from wood treated with CCA and copper from ACQ, CuAz, or a mixture of CCA-, ACQ-, and CuAz-treated wood in single step. The extraction proceeded efficiently with 6 h of treatment, and was insensitive to the differences in chemical characteristics, including solubility of individual elements. After 6 h of treatment, approximately 90% of chromium, copper, and arsenic were effectively removed from wood treated with CCA or a mixture of CCA, ACQ, and CuAz and 90% of copper from ACQ- and CuAz-treated wood. These results demonstrate that the solvent extraction technique using pH-adjusted bioxalate solution with sodium hydroxide is a promising method for pollution minimization by various types of wastes contaminated with heavy metals and arsenic. PMID:16641329

Kakitani, Tomo; Hata, Toshimitsu; Kajimoto, Takeshi; Imamura, Yuji

2006-01-01

264

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

NASA Astrophysics Data System (ADS)

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

Jenkins, Kurt; Starkey, Edward

1996-09-01

265

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

266

Habitat and host associations of Craterellus tubaeformis in northwestern Oregon.  

PubMed

Knowledge of the habitat and host associations of Craterellus tubaeformis (winter chanterelle) is the key to understanding the ecological characteristics needed for its conservation. In this study, a survey of forest types in northwestern Oregon for mycorrhizal associates is performed and the hypotheses that stand age and the volume of well-decayed, coarse, woody debris (CWD) are significant to the standing crop biomass and the probability of C. tubaeformis occurrence are tested. Host associations were identified with polymerase chain reaction (PCR) amplification and restriction fragment-length polymorphism (RFLP) typing. Habitat associations were tested by measurements on 64 plots in the Coast and Cascade Ranges of northwestern Oregon. Data analysis found that stand age and well-decayed, coarse, woody debris were related significantly to the probability of C. tubaeformis occurrence but not to standing crop biomass. Results indicated the volume of well-decayed CWD is particularly important to the probability of C. tubaeformis occurrence in stands less than 100 yr of age. Well-decayed CWD was the substratum for 88% of C. tubaeformis sporocarps across all stands, despite the fact that ground area coverage of CWD ranged only from 3 to 26%. Slope, elevation and aspect were not related to the probability of C. tubaeformis occurrence or standing crop biomass. The occurrence of C. tubaeformis in northwestern Oregon is highly correlated to the presence of western hemlock (Tsuga heterophylla), and their mycorrhizal association was confirmed. Craterellus tubaeformis also can form mycorrhizae with Douglasfir (Pseudotsuga menziesii) and Sitka spruce (Picea sitchensis) but is encountered only rarely in stands without a hemlock component. In northwestern Oregon, the presence of Hydnum spp. in a stand is a good indicator of the presence of C. tubaeformis. Differences in genetic sequences between C. tubaeformis populations in western North America, eastern North America and Europe suggest the likelihood of several distinct species. PMID:21148873

Trappe, M J

2004-01-01

267

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

NASA Astrophysics Data System (ADS)

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

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

268

13 C content of ecosystem respiration is linked to precipitation and vapor pressure deficit  

Microsoft Academic Search

Variation in the carbon isotopic composition of ecosystem respiration (?13CR) was studied for 3 years along a precipitation gradient in western Oregon, USA, using the Keeling plot approach. Study sites included six coniferous forests, dominated by Picea sitchensis, Tsuga heterophylla, Pseudotsuga menziesii, Pinus ponderosa, and Juniperus occidentalis, and ranged in location from the Pacific coast to the eastern side of

David R. Bowling; Nate G. McDowell; Barbara J. Bond; Beverly E. Law; James R. Ehleringer

2002-01-01

269

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...

270

Large wood recruitment and redistribution in headwater streams in the southern Oregon Coast Range, U.S.A  

Microsoft Academic Search

Large wood recruitment and redistribution mechanisms were investigated in a 3.9 km2 basin with an old- growth Pseudotsuga menziesii (Mirb.) Franco and Tsuga heterophylla (Raf.) Sarg. forest, located in the southern Coast Range of Oregon. Stream size and topographic setting strongly influenced processes that delivered wood to the channel network. In small colluvial channels draining steep hillslopes, processes associated with

Christine L. May; Robert E. Gresswell

2003-01-01

271

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

272

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

E-print Network

-tolerant yellow pines and oaks are being replaced by shade-tolerant, fire sensitive species such as red maple (Acer rubrum L.) and hemlock (Tsuga canadensis L. Carr.). Classification analysis and ordination of species composition in different age classes suggest a...

Flatley, William 1977-

2012-08-31

273

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

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

Multivariate bird-habitat relationships models for some Northern Region bird species  

E-print Network

pine (Pinus contorta) SPRUCFIR: Percent of total canopy cover made up by spruce/fir (Picea, Abies lasiocarpa) #12;4 4 MESIC: Percent of total canopy cover made up by cedar (Thuja), hemlock (Tsuga) and Grand Fir (Abies grandis). STONPINE: Percent of total canopy cover made up by whitebark pine (Pinus

Montana, University of

276

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

E-print Network

and Molecular Plant Physiology Program, Pennsylvania State University, University Park, PA 16802, USA; *Author alleghaniensis), eastern hemlock (Tsuga ca- nadensis), and red oak (Quercus rubra). The five species varied - , and resin bag NO3 - ). In con- trast, red oak plots had near-average net mineralization rates and soil C

Berkowitz, Alan R.

277

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

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

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

278

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

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

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

279

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

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

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

280

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

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

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

281

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

282

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

283

INDIANA BAT, MYOTIS SODALIS, MATERNITY ROOSTS IN THE SOUTHERN UNITED STATES  

Microsoft Academic Search

We characterized Indiana bat (Myotis sodalis) roosting habitat at three maternity colony sites in western North Carolina and eastern Tennessee. Using radio telemetry, we tracked six bats a total of 40 bat days (range 4-9 days\\/ bat). In 1999, we located a primary roost in an eastern hemlock (Tsuga canadensis) snag (109 cm DBH) in the Nantahala National Forest, NC.

Eric R. Britzke; Michael J. Harvey; Susan C. Loeb

2003-01-01

284

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

285

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

286

Simulating Secondary Succession of Elk Forage Values in a Managed Forest Landscape, Western Washington  

PubMed

Modern timber management practices often influence forage production for elk (Cervus elaphus) on broad temporal and spatial scales in forested landscapes. We incorporated site-specific information on postharvesting forest succession and forage characteristics in a simulation model to evaluate past and future influences of forest management practices on forage values for elk in a commercially managed Douglas fir (Pseudotsuga menziesii, PSME)-western hemlock (Tsuga heterophylla, TSHE) forest in western Washington. We evaluated future effects of: (1) clear-cut logging 0, 20, and 40% of harvestable stands every five years; (2) thinning 20-year-old Douglas fir forests; and (3) reducing the harvesting cycle from 60 to 45 years. Reconstruction of historical patterns of vegetation succession indicated that forage values peaked in the 1960s and declined from the 1970s to the present, but recent values still were higher than may have existed in the unmanaged landscape in 1945. Increased forest harvesting rates had little short-term influence on forage trends because harvestable stands were scarce. Simulations of forest thinning also produced negligible benefits because thinning did not improve forage productivity appreciably at the stand level. Simulations of reduced harvesting cycles shortened the duration of declining forage values from approximately 30 to 15 years. We concluded that simulation models are useful tools for examining landscape responses of forage production to forest management strategies, but the options examined provided little potential for improving elk forages in the immediate future.KEY WORDS:Cervus elaphus; Elk; Forage; Forest management; Modeling; Secondary succession PMID:8703108

Jenkins; Starkey

1996-09-01

287

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

PubMed

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

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

2008-04-01

288

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

289

Crown conductance and tree and stand transpiration in a second-growth Abies amabilis forest  

Microsoft Academic Search

We measured whole-tree sap flow in a 43-year-old Abies amabilis (Dougl. ex Loud.) Dougl. ex J. Forbes ñ Tsuga heterophylla (Raf.) Sarg. forest in western Washington, U.S.A. We calculated whole-tree crown conductance to water vapor (gcrown) by substituting the sap flow data and meteorological measurements into the inverted PenmanñMonteith equation. Individual tree sap flow and crown conductance varied widely with

T. A. Martin; K. J. Brown; J. Cermák; R. Ceulemans; J. Kucera; F. C. Meinzer; J. S. Rombold; D. G. Sprugel; T. M. Hinckley

1997-01-01

290

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

291

Stomatal frequency adjustment of four conifer species to historical changes in atmospheric CO2.  

PubMed

The species-specific inverse relation between atmospheric CO(2) concentration and stomatal frequency for many woody angiosperm species is being used increasingly with fossil leaves to reconstruct past atmospheric CO(2) levels. To extend our limited knowledge of the responsiveness of conifer needles to CO(2) fluctuations, the stomatal frequency response of four native North American conifer species (Tsuga heterophylla, Picea glauca, Picea mariana, and Larix laricina) to a range of historical CO(2) mixing ratios (290 to 370 ppmV) was analyzed. Because of the specific mode of leaf development and the subsequent stomatal patterning in conifer needles, the stomatal index of these species was not affected by CO(2). In contrast, a new measure of stomatal frequency, based on the number of stomata per millimeter of needle length, decreased significantly with increasing CO(2). For Tsuga heterophylla, the stomatal frequency response to CO(2) changes in the last century is validated through assessment of the influence of other biological and environmental variables. Because of their sensitive response to CO(2), combined with a high preservation capacity, fossil needles of Tsuga heterophylla, Picea glauca, P. mariana, and Larix laricina have great potential for detecting and quantifying past atmospheric CO(2) fluctuations. PMID:21659156

Kouwenberg, Lenny L R; McElwain, Jennifer C; Kürschner, Wolfram M; Wagner, Friederike; Beerling, David J; Mayle, Francis E; Visscher, Henk

2003-04-01

292

Report on survey of Western Hemlock  

E-print Network

...................................................................................21 Native species..............................................................................................21 Non-native species Native species

293

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

294

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

295

Homogenization of northern U.S. Great Lakes forests due to land use  

E-print Network

and structural variables Axis 1 Axis 2 Axis 3 r r r Ash (Fraxinus spp.) 0.23 Ã?0.38 Ã?0.59 Aspen (Populus spp.) Ã?0.15 Fir (Abies balsamifera) 0.15 0.58 Ã?0.47 Hemlock (Tsuga canadensis) 0.45 0.02 0.77 Hickory (Carya spp a lower relative dominance of conifers in comparison to the pre- Euro-American period. Aspen (Populus

Mladenoff, David

296

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

297

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

298

Biophysical controls of carbon flows in three successional Douglas-fir stands based on eddy-covariance measurements.  

PubMed

We measured net carbon flux (F(CO2)) and net H2O flux (F(H2O)) by the eddy-covariance method at three Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)-western hemlock (Tsuga heterophylla (Raf.) Sarg.) sites located in the Wind River Valley of southern Washington State, USA. Stands were approximately 20, 40 and 450 years old and measurements were made between June 15 and October 15 of 1998 in the 40- and 450-year-old stands, and of 1999 in the 20- and 450-year-old stands. Our objectives were to determine if there were differences among the stands in: (1) patterns of daytime F(CO2) during summer and early autumn; (2) empirically modeled relationships between local climatic factors (e.g., light, vapor pressure deficit (VPD), soil water content, temperature and net radiation) and daytime F(CO2); and (3) water-use efficiency (WUE). We used the Landsberg equation, a logarithmic power function and linear regression to model relationships between F(CO2) and physical variables. Overall, given the same irradiance, F(CO2) was 1.0-3.9 mol m-2 s-1 higher (P < 0.0001 for both seasons) at the two young stands than at the old-growth stand. During summer and early autumn, F(CO2) averaged 4.2 and 6.1 mol m-2 s-1 at the 20- and 40-year-old stand, respectively. In contrast, the 450-year-old forest averaged 2.2 and 3.2 mol m-2 s-1 in 1998 and 1999, respectively. Increases in VPD were associated with reduced F(CO2) at all three stands, with the greatest apparent constraints occurring at the old-growth stand. Correlations between F(CO2) and all other environmental variables differed among ecosystems, with soil temperature showing a negative correlation and net radiation showing a positive correlation. In the old-growth stand, WUE was significantly greater (P < 0.0001) in the drier summer of 1998 (2.7 mg g-1) than in 1999 (1.0 mg g-1). Although we did not use replicates in our study, the results indicate that there are large differences in F(CO2) among Douglas-fir stands of different ages growing in the same general area, and that variations in age structure and site conditions need to be considered when scaling flux measurements from individual points to the landscape level. PMID:11830413

Chen, Jiquan; Falk, Matthias; Euskirchen, Eugénie; U, Kyaw Tha Paw; Suchanek, Thomas H; Ustin, Susan L; Bond, Barbara J; Brosofske, Kimberley D; Phillips, Nathan; Bi, Runcheng

2002-02-01

299

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

300

Seasonal biochemical changes in coniferous forest canopies and their response to fertilization.  

PubMed

Seasonal changes in concentrations of total nitrogen, free amino acids, chlorophyll, starch and sugar were measured in foliage from fertilized and unfertilized conifer forests in New Mexico and Oregon. In the New Mexico Douglas-fir (Pseudotsuga menziesii var glauca (Beissn.) Franco) forest, fertilization resulted in elevated foliar nitrogen concentrations on all dates, from an average of 9 mg g(-1) in unfertilized trees to 14 mg g(-1) in fertilized trees. In the Oregon western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest, fertilization increased total N by only 15%, from 13 mg g(-1) in unfertilized trees to 15 mg g(-1) in fertilized trees. Foliar nitrogen concentrations on a weight basis were lowest in winter and spring, but did not vary seasonally when expressed on a leaf area basis. Chlorophyll concentrations increased with fertilization and had greater seasonal variation than did total nitrogen concentrations. Chlorophyll concentrations were significantly higher during the growing season than in the winter and spring months. Fertilization did not result in major changes in the proportion of total nitrogen in chlorophyll at either the Oregon or the New Mexico site. Concentrations of free amino acids varied with date and fertilization treatment; in New Mexico, amino acids were highest in the winter sample, whereas in Oregon, they were lowest in winter and spring. At both sites, amino acid concentrations were significantly higher in fertilized trees than in control trees on most dates and the ratios of amino acid-N to total N were also significantly higher in fertilized trees. For both sites, starch concentrations were nearly zero for most of the year, but increased sharply just before bud break and initiation of new growth in the spring. Although fertilization resulted in increased nitrogen concentrations in foliage at both sites, the response in New Mexico was much greater than in Oregon. These results are in agreement with forest productivity data that suggest that growth in the New Mexico site is limited by nitrogen, whereas in the Oregon site it is not. PMID:14967674

Billow, C; Matson, P; Yoder, B

1994-06-01

301

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

302

Chaenothecopsis nigripunctata, a remarkable new species of resinicolous Mycocaliciaceae from western North America.  

PubMed

The new species Chaenothecopsis nigripunctata (Mycocaliciaceae, Ascomycota) is described from western North America. The fungus grows on resin and wetwood of Tsuga heterophylla in moist temperate forests. It differs from its relatives in the regular production of polycephalic ascomata with contiguous capitula. The species is further characterized by a well-developed mazaedium. An unevenly thickened epithecium acts to compartmentalize the mazaedium into several columns per apothecial disk. Dark spore masses against the pale epithecium give the fungus a highly distinctive, elegant appearance. This species is not easily accommodated in Chaenothecopsis in a traditional sense but it is placed in this genus pending a better understanding of relationships within the Mycocaliciaceae. PMID:21156593

Rikkinen, Jouko

2003-01-01

303

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

304

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

305

Forest types of the coastal western hemlock zone.  

E-print Network

??This thesis contributes analytical and synthetical data on the forest phytocoenoses and proposes a classification. Detailed floristical and environmental descriptions are given, also consideration of… (more)

Orlo?ci, La?szlo?

2012-01-01

306

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

307

Carbon exchange and quantum efficiency of ecosystem carbon storage in mature deciduous and old-growth coniferous forest in central New England in 2001  

NASA Astrophysics Data System (ADS)

Carbon storage in forests of the northeastern U.S. and adjacent Canada may be a significant carbon sink, as forests and soils in this region have recovered after agricultural abandonment in the 19th century. Data collected during the 1990's showed that an area of 70 to 100 year old deciduous forest on abandoned farmland in central Massachusetts stored an average of 2.0 Mg C/ha/yr in trees and soil. During 2001 we measured carbon exchange and environmental parameters (above-canopy air temperature, atmospheric humidity, photosynthetically active radiation (PAR) and soil temperature) in both the 70-100 year old deciduous forest and in a nearby eastern hemlock (Tsuga canadensis L.)-dominated forest with trees up to 220 years old that was never cleared for agricultural use. The deciduous forest stored more than 4 Mg C/ ha in 2001, far higher than in any previous year since measurements started in 1991. Highest monthly deciduous forest carbon storage (1.8 - 1.9 Mg ha-1 month-1) occurred in July and August. The hemlock forest stored about 3 Mg C/ha, with peak storage in April and May (0.8 - 0.9Mg C ha-1 month-1), and little or no C storage during August. The differences in carbon storage between the two forests were related to differences in quantum use efficiency. Quantum efficiency of ecosystem carbon storage in the foliated deciduous forest averaged about 0.16 g C /mol PAR and was insensitive to temperature after leaf maturation. In contrast, the average hemlock forest quantum efficiency declined from about 0.10 g C /mol PAR at daily average above-canopy air temperature (T{a}{v}{g}) = 5 oC to zero quantum efficiency (no net carbon storage) at T{a}{v}{g} = 23 oC. Optimum temperatures for carbon storage in the hemlock forest occurred in April. Differences between the two forests are likely due primarily to a higher maximum photosynthetic rate and a more positive temperature response of leaf-level photosynthesis in red oak (the dominant deciduous species) as compared with eastern hemlock. Maintenance of high soil respiration in the hemlock forest during warm dry summer weather may also contribute to declining quantum efficiency of carbon storage in the hemlock forest during the summer.

Hadley, J. L.; Urbanski, S. P.

2002-12-01

308

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

Microsoft Academic Search

Old-growth forests are known for their complex and variable structure and function. In a 12-ha plot (300 m x 400 m) of an old-growth Douglas-fir forest within the T. T. Munger Research Natural Area in southern Washington, we mapped and recorded live\\/dead condition, species, and diameter at breast height to address the following objectives: (1) to quantify the contribution of

Jiquan Chen; Bo Song; Mark Rudnicki; Melinda Moeur; Ken Bible; Malcolm North; Dave C. Shaw; Jerry F. Franklin; Dave M. Braun

2004-01-01

309

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

310

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

PubMed

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

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

2007-01-01

311

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

312

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

313

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

Federal Register 2010, 2011, 2012, 2013, 2014

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2011-12-28

314

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

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2011-12-09

315

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

316

Habitat classification: A comparison using avian species and guilds  

NASA Astrophysics Data System (ADS)

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

Degraaf, Richard M.; Chadwick, Nan L.

1984-11-01

317

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

318

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

319

Seizures and death on a white river float trip. Report of water hemlock poisoning.  

PubMed

White river rafting is becoming a major summer recreational activity throughout the United States. Many people who are ill prepared physically or emotionally to survive will find themselves isolated and in extremely dangerous situations without access to medical help. In addition to the physical dangers of drowning, there are dangers that exist in the concept of "living off the land" and foraging for food. Cicuta douglasii is found in all of our western states, is extremely toxic and can easily be confused with wild parsnip or carrot. Physicians and poison control centers need to be aware of the common poisonous plants in their area and be prepared to treat cases of poisoning from these plants. PMID:4013278

Landers, D; Seppi, K; Blauer, W

1985-05-01

320

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

321

Management Strategies for Annosus Root Disease in Pacific Northwest Coastal Western Hemlock1  

E-print Network

in Western North America. April 18-21, 1989, Monterey, California. 2 Manager/Forest Pathologist, Forest Health, Washington State Department of Natural Resources, Olympia, Washington. The actual amount of fiber that land on mountain beaver or bear wounds. When stands are commercially entered, logging equipment makes

Standiford, Richard B.

322

Intermediate disturbance in a late-successional hemlock-northern hardwood forest  

Microsoft Academic Search

Summary 1 An old-growth mesic forest in northern Michigan, USA, experienced an unusually intense storm in July 2002. Permanent inventory plots and a 2.9-ha mapped stand allow comparison of effects of this rare disturbance with patterns of 'baseline' mortality. 2 Tree mortality attributable to immediate effects of the storm was of similar magnitude to mortality over the previous decade, amounting

KERRY D. WOODS

2004-01-01

323

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

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...APHIS-2012-0060, Regulatory Analysis and Development, PPD, APHIS, Station 3A-03.8, 4700 River Road Unit 118...National Environmental Policy Act of 1969 (NEPA), as amended (42 U.S.C. 4321 et seq.); (2) regulations of the...

2012-08-03

324

A Comparison of Physiological Model Estimates and Flux Data for Carbon Exchange of a Central New England Conifer Forest  

NASA Astrophysics Data System (ADS)

Chamber measurements of net photosynthesis (Pn), leaf respiration, wood respiration (Rw) and soil respiration (Rs) were used to develop carbon exchange models for a central New England eastern hemlock (Tsuga canadensis L.) forest in 1997 through 1999. Major environmental variables driving the Pn model were photosynthetically active radiation, daily minimum air temperature, current air temperature, water vapor pressure deficit and time of day. All respiration terms were primarily exponential temperature functions with Q10's of 1.9 to 3.4. A separate model was developed for Rw during wood production in spring and summer. Rs comprised 60 to 80% of total respiration, varying with time of year. The models were run with hourly climatic data, and compared with measurements of whole-forest carbon exchange using eddy covariance analysis in late 2000 and 2001. Both the models and flux data showed that 50% or more of annual carbon storage in the hemlock forest occurred in April, May, and October when leaves in nearby deciduous forests were not present, incompletely developed, or senescent. High carbon storage in the hemlock forest during spring was driven by long photoperiods and cool soils, which limited Rs during April and May to only about 10% and 35%, respectively, of the maximum Rs in August. Models predicted a major decline in carbon storage in June and carbon loss from the ecosystem during July and August due to high ecosystem respiration. Eddy covariance data showed only a slight drop in storage between May and July, and a sharp decline to near-zero net storage in August. Models also predicted less annual carbon storage than the 2 to 3 Mg ha-1 yr-1 indicated by eddy covariance measurements. A major uncertainty in the models is leaf area index, which if underestimated could explain most of the differences between models and eddy covariance in estimated ecosystem carbon exchange. Both models and eddy covariance data indicate that warmer spring and fall weather, particularly fewer subfreezing nights, are likely to stimulate hemlock forest carbon storage, but hotter summers will reduce it.

Hadley, J. L.; Schedlbauer, J. M.

2002-05-01

325

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

326

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

327

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

328

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

329

Interactions of Carbon Gain and Nitrogen Addition in a Temperate Forest  

NASA Astrophysics Data System (ADS)

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

Bazzaz, F. A.

2001-12-01

330

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

331

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

332

Relative Contribution of Hemlock Pollen to the Phosphorus Loading of the Clear Lake Ecosystem Near Minden, Ontario  

Microsoft Academic Search

The forest stand composition within the terrestrial watershed of a small lake on the southern Precambrian Shield was assessed. Total phosphorus inputs from the terrestrial watersheds were obtained for two sub inflows by measuring flow rates and phosphorus concentrations. Direct aerial phosphorus fallout was estimated from nearby sites sampled by the Ontario Ministry of the Environment. Pollen fallout on the

Hugh H. Banks; James E. Nighswander; White Cedar; Balsam Poplar; Sugar Maple; Red Maple; Striped Maple; Red Oak

333

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

334

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

335

Macromolecular characteristics of lignin and kinetics of delignification of western hemlock in a flow-through reactor under alkaline conditions  

SciTech Connect

Thin (0.4 mm) wood platelets were delignified with aqueous 1.0 N sodium hydroxide in a flow-through reactor at different temperatures in the range 150-180/sup 0/C. All of the soluble lignin fragments did not appear in the reactor effluent immediately after they were detached from the lignin gel as a result of hydrolytic bond cleavage reactions. However, on the basis of results of residual lignin determinations, i.e., without considering the effect of diffusion of sol lignin out of the wood residue, mathematical expression for the kinetics of delignification or for the depletion of the gel lignin as a function of time can be written as a three term exponential equation with constant pre-exponential factors. The equation is interpreted in terms of three types of parallel first order reactions. Taken as a whole, lignin can be viewed as being composed of chains of bifunctionally joiden monomers, C/sub 6/-C/sub 3/ elements, and tetrafunctional crosslinking units, each one consisting of the two monomers which are involved in the crosslinking. The mathematical formulations which long ago have been derived by Flory and Stockmeyer to describe this type of a polymer appear to give meaningful results when experimentally determined weight and number average molecular weights of sol lignin are used in calculations. Computed results indicate significant structural differences in the lignin of different wood species.

Dolk, M.A.

1985-01-01

336

Sedimentologic and palynologic records of the last deglaciation and Holocene from Ballston Lake, New York  

NASA Astrophysics Data System (ADS)

Continuous pollen and sediment records from two ˜8.5-m-long cores document late Pleistocene and Holocene sedimentation and vegetation change in the Ballston Lake basin, eastern New York State. Pebbles at the base of both cores and the geomorphology of the watershed reflect the presence of the Mohawk River in the basin prior to ˜12,900 ± 70 cal yr B.P. Ballston Lake formed at the onset of the Younger Dryas (YD) by an avulsion of the Mohawk River. The transition from clay to gyttja with low magnetic susceptibility (MS), low bulk density, and high organic carbon indicates rapid warming and increased lake productivity beginning 11,020 cal yr B.P. MS measurements reveal that the influx of magnetic particles, associated with pre-Holocene clastic sedimentation, ceased after ˜10,780 cal yr B.P. The pollen record is subdivided into six zones: BL1 (12,920 to 11,020 cal yr B.P.) is dominated by boreal forest pollen; BL2 (11,020 to 10,780 cal yr B.P.) by pine ( Pinus) forest pollen; BL3 (10,780 to 5290 cal yr B.P.) by hemlock ( Tsuga) and mixed hardwood pollen; BL4 (5290 to 2680 cal yr B.P.) by mixed hardwood pollen; BL5a (2680 cal yr B.P. to 1030 cal yr B.P.) by conifer and mixed hardwood pollen; and BL5b (1030 cal B.P. to present) by increasing ragweed ( Ambrosia) pollen. A 62% decrease in spruce ( Picea) pollen in <320 cal years during BL1 reflects rapid warming at the end of the YD. Holocene pollen zones record more subtle climatic shifts than occurred at the end of the YD. One of the largest changes in the Holocene pollen spectra began ˜5300 cal yr B.P., and is characterized by a marked decline in hemlock pollen. This has been noted in other pollen records from the region and may record preferential selection of hemlock by a pathogen or parasites.

Toney, Jaime L.; Rodbell, Donald T.; Miller, Norton G.

2003-09-01

337

Large wood recruitment and redistribution in headwater streams in the southern Oregon Coast Range, U.S.A  

USGS Publications Warehouse

Large wood recruitment and redistribution mechanisms were investigated in a 3.9 km2 basin with an old-growth Pseudotsuga menziesii (Mirb.) Franco and Tsuga heterophylla (Raf.) Sarg. forest, located in the southern Coast Range of Oregon. Stream size and topographic setting strongly influenced processes that delivered wood to the channel network. In small colluvial channels draining steep hillslopes, processes associated with slope instability dominated large wood recruitment. In the larger alluvial channel, windthrow was the dominant recruitment process from the local riparian area. Consequently, colluvial channels received wood from further upslope than the alluvial channel. Input and redistribution processes influenced piece location relative to the direction of flow and thus, affected the functional role of wood. Wood recruited directly from local hillslopes and riparian areas was typically positioned adjacent to the channel or spanned its full width, and trapped sediment and wood in transport. In contrast, wood that had been fluvially redistributed was commonly located in mid-channel positions and was associated with scouring of the streambed and banks. Debris flows were a unique mechanism for creating large accumulations of wood in small streams that lacked the capacity for abundant fluvial transport of wood, and for transporting wood that was longer than the bank-full width of the channel.

May, Christine L.; Gresswell, Robert E.

2003-01-01

338

A 14,300-year-long record of fire-vegetation-climate linkages at Battle Ground Lake, southwestern Washington  

NASA Astrophysics Data System (ADS)

High-resolution macroscopic charcoal analysis was used to reconstruct a 14,300-year-long fire history record from the lower Columbia River Valley in southwestern Washington, which was compared to a previous vegetation reconstruction for the site. In the late-glacial period (ca. 14,300-13,100 cal yr BP), Pinus/ Picea-dominated parkland supported little to no fire activity. From the late-glacial to the early Holocene (ca. 13,100-10,800 cal yr BP), Pseudotsuga/ Abies-dominated forest featured more frequent fire episodes that burned mostly woody vegetation. In the early to middle Holocene (ca. 10,800-5200 cal yr BP), Quercus-dominated savanna was associated with frequent fire episodes of low-to-moderate severity, with an increased herbaceous (i.e., grass) charcoal content. From the middle to late Holocene (ca. 5200 cal yr BP to present), forest dominated by Pseudotsuga, Thuja-type, and Tsuga heterophylla supported less frequent, but mostly large or high-severity fire episodes. Fire episodes were least frequent, but were largest or most severe, after ca. 2500 cal yr BP. The fire history at Battle Ground Lake was apparently driven by climate, directly through the length and severity of the fire season, and indirectly through climate-driven vegetation shifts, which affected available fuel biomass.

Walsh, Megan K.; Whitlock, Cathy; Bartlein, Patrick J.

2008-09-01

339

Evidence for Millennial-Scale Climate Change During Marine Isotope Stages 2 and 3 at Little Lake, Western Oregon, U.S.A.  

NASA Astrophysics Data System (ADS)

Pollen and geochemical data from Little Lake, western Oregon, suggest several patterns of millennial-scale environmental change during marine isotope stage (MIS) 2 (14,100-27,600 cal yr B.P.) and the latter part of MIS 3 (27,600-42,500 cal yr B.P.). During MIS 3, a series of transitions between warm- and cold-adapted taxa indicate that temperatures oscillated by ca. 2°-4°C every 1000-3000 yr. Highs and lows in summer insolation during MIS 3 are generally associated with the warmest and coldest intervals. Warm periods at Little Lake correlate with warm sea-surface temperatures in the Santa Barbara Basin. Changes in the strength of the subtropical high and the jet stream may account for synchronous changes at the two sites. During MIS 2, shifts between mesic and xeric subalpine forests suggest changes in precipitation every 1000-3000 yr. Increases in Tsuga heterophylla pollen at 25,000 and 22,000 cal yr B.P. imply brief warmings. Minimum summer insolation and maximum global ice-volumes during MIS 2 correspond to cold and dry conditions. Fluctuations in precipitation at Little Lake do not correlate with changes in the Santa Barbara Basin and may be explained by variations in the strength of the glacial anticyclone and the position of the jet stream.

Grigg, Laurie D.; Whitlock, Cathy; Dean, Walter E.

2001-07-01

340

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

341

Using the thermal infrared multispectral scanner (TIMS) to estimate surface thermal responses  

NASA Astrophysics Data System (ADS)

A series of measurements was conducted over the H.J. Andrews, Oregon, experimental coniferous forest, using airborne thermal infrared multispectral scanner (TIMS). Flight lines overlapped, with a 28-min time difference between flight lines. Concurrent radiosonde measurements of atmospheric profiles of air temperature and moisture were used for atmospheric radiance corrections of the TIMS data. Surface temperature differences over time between flight lines were used to develop thermal response numbers (TRNs) which characterized the thermal response (in KJ/sq m/C, where K is the measured incoming solar radiation) of the different surface types. The surface types included a mature forest (canopy dominated by dense crowns of Pseudosuga menziesii, with a secondary canopy of dense Tsuga heterophylla, and also a tall shrub layer of Acer circinatum) and a two-year-old clear-cut. The temperature distribution, within TIMS thermal images was found to reflect the surface type examined. The clear-cut surface had the lowest TRN, while mature Douglas fir the highest.

Luvall, J. C.; Holbo, H. R.

1987-07-01

342

Tree host range and world distribution of the extomycorrhizal fungus Pisolithus tinctorius.  

PubMed

The natural occurrence of Pisolithus tinctorius has been confirmed in 33 countries of the world and in 38 states in the United States. This ectomycorrhizal fungus is found associated with various tree species in nurseries, urban areas, orchards, forests, and strip-mined spoils. Experiments have proved that this fungal symbiont forms ectomycorrhizae with Abies procera, Betula pendula, Carya illnoensis, 11 species of Eucalyptus, 30 species of Pinus, Pseudotsuga menziesii var. meniziesii, 2 species of Quercus, and Tsuga heterophylla. Pisolithus has also been reported growing under natural conditions in association with three additional species of Betula, two species of Eucalyptus, nine species of Pinus, and eight species of Quercus, Populus tremuloides, Pseudotsuga grandidenta, and Salix humilis. This fungal symbiont has great potential in forestation efforts because of (1) the availability of practical techniques for artificially introducing in into nursery soils; (2) its ability to improve tree survival and growth in the nursery and the field; (3) its near worldwide distribution on a variety of sites; and (4) its broad host range encompassing many of the world's most important tree species. PMID:856419

Marx, D H

1977-03-01

343

Using the thermal infrared multispectral scanner (TIMS) to estimate surface thermal responses  

NASA Technical Reports Server (NTRS)

A series of measurements was conducted over the H.J. Andrews, Oregon, experimental coniferous forest, using airborne thermal infrared multispectral scanner (TIMS). Flight lines overlapped, with a 28-min time difference between flight lines. Concurrent radiosonde measurements of atmospheric profiles of air temperature and moisture were used for atmospheric radiance corrections of the TIMS data. Surface temperature differences over time between flight lines were used to develop thermal response numbers (TRNs) which characterized the thermal response (in KJ/sq m/C, where K is the measured incoming solar radiation) of the different surface types. The surface types included a mature forest (canopy dominated by dense crowns of Pseudosuga menziesii, with a secondary canopy of dense Tsuga heterophylla, and also a tall shrub layer of Acer circinatum) and a two-year-old clear-cut. The temperature distribution, within TIMS thermal images was found to reflect the surface type examined. The clear-cut surface had the lowest TRN, while mature Douglas fir the highest.

Luvall, J. C.; Holbo, H. R.

1987-01-01

344

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

345

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

346

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

347

Ecological boundary detection using Bayesian areal wombling  

PubMed Central

The study of ecological boundaries and their dynamics is of fundamental importance to much of ecology, biogeography, and evolution. Over the past two decades, boundary analysis (of which wombling is a subfield) has received considerable research attention, resulting in multiple approaches for the quantification of ecological boundaries. Nonetheless, few methods have been developed that can simultaneously (1) analyze spatially homogenized data sets (i.e., areal data in the form of polygons rather than point-reference data); (2) account for spatial structure in these data and uncertainty associated with them; and (3) objectively assign probabilities to boundaries once detected. Here we describe the application of a Bayesian hierarchical framework for boundary detection developed in public health, which addresses these issues but which has seen limited application in ecology. As examples, we analyze simulated spread data and the historic pattern of spread of an invasive species, the hemlock woolly adelgid (Adelges tsugae), using county-level summaries of the year of first reported infestation and several covariates potentially important to influencing the observed spread dynamics. Bayesian areal wombling is a promising approach for analyzing ecological boundaries and dynamics related to changes in the distributions of native and invasive species. PMID:21302814

Fitzpatrick, Matthew C.; Preisser, Evan L.; Porter, Adam; Elkinton, Joseph; Waller, Lance A.; Carlin, Bradley P.; Ellison, Aaron M.

2014-01-01

348

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

349

Management of Westside Washington Conifer Stands Infected with Heterobasidion annosum1  

E-print Network

disease is illustrated in management of mountain goat habitat. Good mountain goat habitat typically the western hemlock, mountain hemlock, and Pacific silver fir zones west of the Cascades. In stands managed widespread in old-growth western hemlock, mountain hemlock, and Pacific silver fir stands west

Standiford, Richard B.

350

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

PubMed

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

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

2014-07-01

351

Ann. For. Sci. 65 (2008) 203 Available online at: c INRA, EDP Sciences, 2008 www.afs-journal.org  

E-print Network

. mariana, Pinus strobus, Populus tremuloides, and Tsuga canadensis. Stem heights and diameters were rubens, Pinus strobus, Populus tremuloides et Tsuga canadensis. Le diamètre et la hauteur des troncs ont

Paris-Sud XI, Université de

352

Trends in bole biomass accumulation, net primary production and tree mortality in Pseudotsuga menziesii forests of contrasting age.  

PubMed

Although it is generally accepted that the rate of accumulation of biomass declines as forests age, little is known about the relative contributions to this decline of changes in net primary production (NPP) and tree mortality. We used 10-15 years of observations of permanent plots in three small watersheds in and near the H.J. Andrews Experimental Forest, Oregon, to examine these issues. The three watersheds are of similar elevation and potential productivity and support young (29 years at last measurement), mature (approximately 100 years) and old (approximately 400 years) forest dominated by Pseudotsuga menziesii (Mirb.) Franco and Tsuga heterophylla (Raf.) Sarg. Accumulation of tree bole biomass was greatest in the young stand, reaching approximately 7 Mg ha-1 year-1 in the last measurement interval. Bole biomass accumulation was relatively constant (approximately 4-5 Mg ha-1 year-1) in the mature stand, and there was no net accumulation of bole biomass in the old-forest stand. The NPP of boles increased with time in the young stand, from approximately 3 to approximately 7 Mg ha-1 year-1, but was nearly constant in the mature and old-forest stands, at approximately 6 and 3-4 Mg ha-1 year-1, respectively. Mortality increased slowly in the young stand (from < 0.1 to 0.3 Mg ha-1 year-1), but fluctuated between 1-2 and 2-6 Mg ha-1 year-1 in the mature and old-forest stands, respectively. Thus, declining biomass accumulation with stand age reflects, in approximately equal amounts, both decreasing NPP and increasing mortality. PMID:11830418

Acker, S A; Halpern, C B; Harmon, M E; Dyrness, C T

2002-02-01

353

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

PubMed

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

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

2006-01-01

354

Photosynthetic differences between saplings and adult trees: an integration of field results by meta-analysis.  

PubMed

Ontogenetic changes in gas exchange parameters provide both insight into mechanisms underlying tree growth patterns, and data necessary to scale environmental impacts on young trees to predict responses of older trees. We present a quantitative review and meta-analysis of field measurements of gas exchange parameters in saplings and mature trees of 35 tree species (seven conifers, seven temperate deciduous trees, and 21 tropical evergreen trees). Data for saplings were obtained in both understory environments and open areas or large gaps. We also present data on ontogenetic changes in photosynthesis for Pseudotsuga menziesii (Mirb.) Franco and Tsuga heterophylla (Raf.) Sarg., species of particular interest because of their large maximal heights and long life-spans. Among tree species, there is evidence for both ontogenetic increases and ontogenetic decreases in photosynthetic capacity on a leaf area basis (A(area)). Overall, A(area) is generally higher for upper-canopy leaves of adult trees than for saplings, especially in temperate deciduous trees. However, the pattern for photosynthetic capacity on a leaf mass basis (A(mass)) is the reverse of that observed for A(area). Saplings of both conifers and broad-leaved trees, even when acclimated to low-light conditions, characteristically have a higher A(mass) than adult trees. This pattern is driven largely by an ontogenetic increase in leaf mass per unit area (LMA), as found in 100% of studies reviewed. Data for Pacific Northwest conifers, although including measurements on some of the tallest trees studied, did not differ greatly from patterns found in other tree species. We conclude that ontogenetic changes in LMA are the single most consistent difference between saplings and adult trees, and that changes in LMA and related aspects of leaf morphology may be critical to understanding both variation in gas exchange during tree growth, and stage-dependent responses of trees to environmental change. PMID:11830408

Thomas, Sean C; Winner, William E

2002-02-01

355

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. The dendroecology and climatic impacts for old-growth white pine and hemlock ...  

E-print Network

Reproduced with permission of the copyright owner. Further reproduction prohibited without; Sciences Module pg. 851 #12;Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. #12;Reproduced with permission of the copyright owner. Further reproduction

Thaxton, Christopher S.

356

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

E-print Network

or family entertainment. Encourage wild animals to remain wild.Do not feed them around your home. Make loud with an abundance native wild animals. But sooner or later, most Granite State households primarilyatnon-lethalmeansofreducingconflict. First,afewgeneralprinciples: · Don't treat wild animals as pets

New Hampshire, University of

357

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

358

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

359

Growth rate responses of Lobaria pulmonaria to canopy structure in even-aged and old-growth cedar–hemlock forests of central-interior British Columbia, Canada  

Microsoft Academic Search

The ability of cyanolichens to sustain growth in even-aged forests that develop after clear-cut harvesting is a major conservation biology concern in British Columbia's inland rainforest. This and other conservation issues have led to proposals advocating partial-cut rather than clear-cut harvesting to better maintain the structures that support biodiversity in old-growth forest stands. However, evaluating the potential impacts of alternative

Darwyn S. Coxson; Susan K. Stevenson

2007-01-01

360

Effects of silvicultural practices on carbon stores in Douglas-fir ? western hemlock forests in the Pacific Northwest, U.S.A.: results from a simulation model  

Microsoft Academic Search

We used a new model, STANDCARB, to examine effects of various treatments on carbon (C) pools in the Pacific Northwest forest sector. Simulation experiments, with five replicates of each treatment, were used to investigate the effects of initial conditions, tree establishment rates, rotation length, tree utilization level, and slash burning on eco - system and forest products C stores. The

Mark E. Harmon; Barbara Marks

2002-01-01

361

Relative Abundance of Ambrosia Beetles in an Old-Growth Western Hemlock\\/Pacific Silver Fir Forest and Adjacent Harvesting Areas  

Microsoft Academic Search

Semiochemical-baited mul- tiple-funnel traps were set out in two new logging areas and in mature forest on northeastern Vancouver Island near Kelsey Bay, British Columbia. The large numbers of ambrosia beetles captured indi- cated that Trypodendron lineatum and Gnathotrichus sulcatus are distributed along logging rights-of-way as well as in the surrounding forest. Results suggest that logs must be removed as

John A. McLean; Scott M. Salom

1989-01-01

362

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

363

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.

364

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

USGS Publications Warehouse

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

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

1998-01-01

365

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

366

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

367

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

368

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

369

76 FR 3524 - Final Flood Elevation Determinations  

Federal Register 2010, 2011, 2012, 2013, 2014

...Perry County Maps are available for inspection at 109-A East Gay Street, Somerset, OH 43783. Village of Corning Maps are available...Hemlock Maps are available for inspection at 8810 Main Street Southeast, Hemlock, OH...

2011-01-20

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

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

372

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

373

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

374

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

375

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

376

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

377

A Pacific Northwest old-growth forest's response to climate variability and extreme climate events over 10 years.  

NASA Astrophysics Data System (ADS)

This study analyses eddy-covariance (EC) measurements carried out over a 10 year period in a Pacific Northwest old-growth Douglas-fir (Pseudotsuga menzesii) and Western Hemlock (Tsuga heterophyllia) forest (500-years old) in southern Washington State, USA and characterizes the seasonal and interannual variability in net ecosystem productivity (NEP), gross primary productivity (GPP) and ecosystem respiration (Reco) and primary climatic controls on these fluxes. This forest acted on average as a carbon (C) sink during the study period. However the forest transitioned from an annual net carbon sink (NEP = + 217 g C m-2 year-1) in 1999 to a source (NEP = - 100 g C m-2 year-1) in 2003. The measurement period included three moderate to strong ENSO events, a major shift in the PDO as well as seasonal drought and cold extremes. The carbon sink year (1999) occurred during a strong La Niña while the source year (2003) occurred during El Niño. When ocean-atmospheric ciculations were in- phase, i.e. all were negative (cool) or positive (warm), the greatest anomalies in carbon flux and mechanistic variables (light use-, water use-efficiency) were observed. Annual averages were + 0.63 g C m-2 day-1 (- 0.27 g C m-2 day-1) for NEP, 3.1 mg C / g H2O (4.1 mg C / g H2O) for WUE, and 1.7 g C MJ-1 (2.1 g C MJ-1) for diffuse LUE during in-phase cool (warm) years. Over the 10 years, we observed high variability in seasonal temperature and precipitation including severe summer drought (2002) and record annual rainfall (1998-1999, 2000-2001). Seasonal to interannual variability in precipitation and the consequent water balance appears to influence the timing of the switch from photosynthesis-dominance to respiration-dominance, ultimately determining whether the forest will be an annual net carbon sink (switches in late summer) or source (switches in early summer). Years with average climate were observed to be average both in NEE and Reco, but enhanced (1999) or suppressed (2003) ecosystem respiration had a significant influence on the carbon balance of the old- growth forest.

Falk, M.; Wharton, S.; Paw U, K. T.; Ustin, S. L.; Schroeder, M.

2008-12-01

378

Phenology of belowground carbon allocation in a mid-latitude forest  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

379

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

380

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.

381

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.

382

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

383

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

384

Indiana's "Most Unwanted" Invasive Plant Pest List FY 2007 The Indiana "Most Unwanted" List, compiled by the Indiana Cooperative Agricultural Pest Survey (CAPS)  

E-print Network

,I,LD Banded elm bark beetle Scolytus schevyrewi Semenov E,I,R,NF Black spruce beetle Tetropium castaneum adelgid Adelges tsugae (Annand) E,I,R,NF Japanese pine sawyer beetle Monochamus alternatus Hope E

Ginzel, Matthew

385

A/C(i) curve analysis across a range of woody plant species: influence of regression analysis parameters and mesophyll conductance.  

PubMed

The analysis and interpretation of A/C(i) curves (net CO(2) assimilation rate, A, versus calculated substomatal CO(2) concentration, C(i)) is dependent upon a number of underlying assumptions. The influence of the C(i) value at which the A/C(i) curve switches between the Rubisco- and electron transport-limited portions of the curve was examined on A/C(i) curve parameter estimates, as well as the effect of mesophyll CO(2) conductance (g(m)) values on estimates of the maximum rate of Rubisco-mediated carboxylation (V(cmax)). Based on an analysis using 19 woody species from the Pacific Northwest, significant variation occurred in the C(i) value where the Rubisco- and electron transport-limited portions of the curve intersect (C(i_t)), ranging from 20 Pa to 152 Pa and averaging c. 71 Pa and 37 Pa for conifer and broadleaf species, respectively. Significant effects on estimated A/C(i) parameters (e.g. V(cmax)) may arise when preliminary estimates of C(i_t), necessary for the multiple regression analyses, are set either too high or too low. However, when the appropriate threshold is used, a significant relationship between A/C(i) and chlorophyll fluorescence estimates of carboxylation is achieved. The use of the V(cmax) parameter to describe accurately the Rubisco activity from the A/C(i) curve analysis is also dependent upon the assumption that C(i) is approximately equal to chloroplast CO(2) concentrations (C(c)). If leaf mesophyll conductance is low, C(c) will be much lower than C(i) and will result in an underestimation of V(cmax) from A/C(i) curves. A large range of mesophyll conductance (g(m)) values was observed across the 19 species (0.005+/-0.002 to 0.189+/-0.011 mol m(-2) s(-1) for Tsuga heterophylla and Quercus garryana, respectively) and, on average, g(m) was 1.9 times lower for the conifer species (0.058+/-0.017 mol m(-2) s(-1) for conifers versus 0.112+/-0.020 mol m(-2) s(-1) for broadleaves). When this mesophyll limitation was accounted for in V(cmax) estimates, considerable variation still existed between species, but the difference in V(cmax) between conifer and broadleaf species was reduced from c. 11 micromol m(-2) s(-1) to 4 micromol m(-2) s(-1). For example, A/C(i) curve estimates of V(cmax) were 31.2+/-6.2 and 42.2+/-4.4 micromol m(-2) s(-1), and A/C(c) curve estimates were 41.2+/-7.1 micromol m(-2) s(-1) and 45.0+/-4.8 micromol m(-2) s(-1), for the conifer and broadleaf species, respectively. PMID:15501912

Manter, Daniel K; Kerrigan, Julia

2004-12-01

386

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

387

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

388

2011 ISRP Retrospective Presented by  

E-print Network

;Hydrosystem Passage RME - Core Projects · Provide long-term data series of smolt-to-adult survival. ·Address improvements will be almost immediate... Hemlock Dam before removal After removal #12;Some will take decades

389

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

390

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

391

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

392

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

393

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

Code of Federal Regulations, 2014 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...

2014-04-01

394

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

2012-06-07

395

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

2012-06-07

396

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

397

29 CFR 1915.72 - Ladders.  

Code of Federal Regulations, 2010 CFR

...cleated ladders up to 30 feet in length. (1) Wood side rails shall be made from West Coast hemlock, Eastern spruce, Sitka spruce, or wood of equivalent strength. Material shall be seasoned, straight-grained wood, and free from...

2010-07-01

398

29 CFR 1915.72 - Ladders.  

Code of Federal Regulations, 2011 CFR

...cleated ladders up to 30 feet in length. (1) Wood side rails shall be made from West Coast hemlock, Eastern spruce, Sitka spruce, or wood of equivalent strength. Material shall be seasoned, straight-grained wood, and free from...

2011-07-01

399

29 CFR 1915.72 - Ladders.  

Code of Federal Regulations, 2013 CFR

...cleated ladders up to 30 feet in length. (1) Wood side rails shall be made from West Coast hemlock, Eastern spruce, Sitka spruce, or wood of equivalent strength. Material shall be seasoned, straight-grained wood, and free from...

2013-07-01

400

29 CFR 1915.72 - Ladders.  

Code of Federal Regulations, 2012 CFR

...cleated ladders up to 30 feet in length. (1) Wood side rails shall be made from West Coast hemlock, Eastern spruce, Sitka spruce, or wood of equivalent strength. Material shall be seasoned, straight-grained wood, and free from...

2012-07-01

401

29 CFR 1915.72 - Ladders.  

Code of Federal Regulations, 2014 CFR

...cleated ladders up to 30 feet in length. (1) Wood side rails shall be made from West Coast hemlock, Eastern spruce, Sitka spruce, or wood of equivalent strength. Material shall be seasoned, straight-grained wood, and free from...

2014-07-01

402

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

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

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

403

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

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

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

404

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

405

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

SciTech Connect

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

Ryan, P.J.

1983-01-01

406

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

407

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

408

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

409

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

410

Direct and indirect effects of white-tailed deer in forest ecosystems$  

E-print Network

Direct and indirect effects of white-tailed deer in forest ecosystems$ Thomas P. Rooney* , Donald M and other ungulates have acted to boost populations of white-tailed deer (Odocoileus virginianus.g. Tsuga canadensis and Thuja occidentalis) as evidenced by demographic analysis. Deer also appear to limit

Waller, Donald M.

411

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

412

Postglacial history of subalpine forests, Olympic Peninsula, Washington, USA  

Microsoft Academic Search

To investigate subalpine vegetation history on the Olympic Peninsula, Washington (USA), two pollen, macrofossil and charcoal records were studied in climatically distinct zones: Martins Lake (1415 m) in the moist Tsuga mertensiana zone and Moose Lake (1508 m) in the drier Abies lasiocarpa zone. The interpretation of fossil pollen assemblages was aided by comparisons with 308 modern assemblages from the

Daniel G. Gavin; Jason S. Mclachlan; Linda B. Brubaker; Kyle A. Young

2001-01-01

413

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.

414

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

415

The effects of feeding by Oniscus asellus on leaf litter sulfur constituents  

Microsoft Academic Search

Feeding by the isopod, Oniscus asellus, produced changes in the sulfur constituents of leaf litter substrates (Acer negundo, A. saccharum, Fagus grandifolia, Picea rubens, and Tsuga canadensis). Isopod consumption of leaf litter generally accelerated the mineralization of carbon-bonded S and increased the formation of ester sulfate in all substrates. After the isopod egestion of A. negundo leaves, fecal decomposition over

C. R. Morgan; M. J. Mitchell

1987-01-01

416

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

417

Wood and Fiber Science, 36(1), 2004, pp. 107118 2004 by the Society of Wood Science and Technology  

E-print Network

Wood and Fiber Science, 36(1), 2004, pp. 107­118 2004 by the Society of Wood Science and Technology). Soil chemical barriers and termite baits have provided promising techniques to pre- vent attack- #12;108 WOOD AND FIBER SCIENCE, JANUARY 2004, V. 36(1) lock (Tsuga Canadensis) (Su and Tamashiro 1986

418

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

419

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

420

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

421

AMICO ET AL. American Journal of Botany 94(4): 558-567. 2007. Data Supplement S1 Page 1 AMICO, GUILLERMO C., ROMINA VIDAL-RUSSELL, AND DANIEL L. NICKRENT. 2007. Phylogenetic relationships and ecological speciation in the  

E-print Network

0 0 0 1 0 1 1 Notanthera heterophylla 0 0 0 0 1 0 0 0 0 1 0 0 1,2 1. Endophytic system, 0: localized: white, 4: green. 12. Pollinator presence, 0: insect, 1: Diglossa not present (hummingbirds), 2: Diglossa

Nickrent, Daniel L.

422

Growth evaluation during the vegetative phase of dicotyledonous weeds and under phosphorus deficiency  

Microsoft Academic Search

With the objective of searching physiological plant traits associated to phosphorus (P) deficiency, growth parameters were evaluated during the early vegetative phase of development in two dicotyledonous wild species with different growth habits, but coexisting in the same environment. Ruellia tuberosa L. and Euphorbia heterophylla L. were grown from seeds collected from nearby unfertilized areas. Sand culture experiments were conducted

Jocelyne Ascencio; José Vicente Lazo

1997-01-01

423

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

424

Ecological Applications, 17(3), 2007, pp. 828839 2007 by the Ecological Society of America  

E-print Network

-TERM PATTERNS IN TROPICAL REFORESTATION: PLANT COMMUNITY COMPOSITION AND ABOVEGROUND BIOMASS ACCUMULATION E of C sequestration peaking at 6.7 6 0.5 Mg CÁha�1 Áyr�1 . Reforestation of pastures resulted; reforestation; secondary forests; secondary succession; Syzygium jambos; Tabebuia heterophylla; tropical forests

Ostertag, Rebecca

425

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

426

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

PubMed

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

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

2004-11-01

427

News from the University of Wisconsin-Madison's Kemp Natural Resources Station Kemp's Point  

E-print Network

News from the University of Wisconsin-Madison's Kemp Natural Resources Station Kemp's Point Volume on lakeshores that are over-developed, and comparing different species of animals and plants that are found or Not to Be by Cindy Fiser Among the great white pines, hemlocks, lakes and bustling summer towns, Wisconsin is also

428

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

429

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

Federal Register 2010, 2011, 2012, 2013, 2014

...DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection...Significant Impact for a Biological Control Agent for Hemlock...United States for use as a biological control agent to reduce the...proposed release of this biological control agent into the...

2011-07-19

430

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

431

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...

432

Influence of high-contrast and low-contrast forest edges on growth rates of Lobaria pulmonaria in the inland rainforest, British Columbia  

Microsoft Academic Search

Forested landscapes in the upper Fraser River watershed face increasing fragmentation from forest harvesting. The resultant edge effects may have a major impact on canopy lichen communities in the surrounding forest matrix. Growth rate responses of large and small thalli of Lobaria pulmonaria were evaluated in transplant experiments conducted in old-growth cedar–Hemlock forest stands located adjacent to clearcut harvest blocks

Darwyn S. Coxson; Susan K. Stevenson

2007-01-01

433

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

434

26 CFR 1.631-2 - Gain or loss upon the disposal of timber under cutting contract.  

Code of Federal Regulations, 2013 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,...

2013-04-01

435

26 CFR 1.631-2 - Gain or loss upon the disposal of timber under cutting contract.  

Code of Federal Regulations, 2012 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,...

2012-04-01

436

26 CFR 1.631-2 - Gain or loss upon the disposal of timber under cutting contract.  

Code of Federal Regulations, 2010 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,...

2010-04-01

437

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

438

Forest Age and Relative Abundance of Pileated Woodpeckers on Southeastern Vancouver Island1  

Microsoft Academic Search

We estimated relative abundance of the pileated woodpeckers (Dryocopus pileatus) at four sites in the Coastal Western Hemlock Biogeoclimatic zone, on southeastern Vancouver Island during 1996-1997. The number of pileated woodpecker calls was correlated with age and structure of forests. Pileated woodpeckers did not use intensively managed forests < 80 years old that had low densities of dead wood (large

Carol L. Hartwig; Donald S. Eastman; Alton S. Harestad

2002-01-01

439

Characteristics of pileated woodpecker ( Dryocopus pileatus) cavity trees and their patches on southeastern Vancouver Island, British Columbia, Canada  

Microsoft Academic Search

Cavity trees and cavity patches (areas around cavity trees) used by pileated woodpeckers were located in Coastal Western Hemlock and Coastal Douglas-fir forest types on southeastern Vancouver Island during 1996 and 1997. Trees with active nests and with apparent pileated cavities (n=28) were larger than trees without cavities (n=200). Of the seven confirmed nest trees, three were grand fir (Abies

C. L. Hartwig; D. S Eastman; A. S Harestad

2004-01-01

440

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

441

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

SciTech Connect

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

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

1980-06-01

442

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

Federal Register 2010, 2011, 2012, 2013, 2014

We are advising the public that the Animal and Plant Health Inspection Service has prepared an environmental assessment and finding of no significant impact relative to the release of Scymnus coniferarum to control hemlock woolly adelgid. Based on its finding of no significant impact, the Animal and Plant Health Inspection Service has determined that an environmental impact statement need not be......

2013-03-06

443

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

444

Properties of commonly used New Hampshire woods  

E-print Network

, before any wood is burned or moved. Questions? If you have general questions feel free to call UNH ­ cord or fraction of cord · Length of the pieces ­ short enough to fit in your wood stove or fireplaceProperties of commonly used New Hampshire woods Pine, Hemlock, Spruce, Aspen Dries and splits

New Hampshire, University of

445

Damage and recovery of tree species after two different tornadoes in the same old growth forest: a comparison of infrequent wind disturbances  

Microsoft Academic Search

Catastrophic wind disturbances in natural forests remain poorly studied, and the literature allows few comparisons of damage and recovery in the same forests disturbed by distinct wind events. Thus, it is still uncertain whether published findings are idiosyncratic or representative. Here I describe damage and recovery patterns in a large, primary hemlock–hardwoods forest in Pennsylvania, USA, which was struck by

Chris J. Peterson

2000-01-01

446

PEST&CROP INDEX 2011 INSECTS, MITES & NEMATODES  

E-print Network

for Yellowing of Soybeans - 14 #12;Millipede Nematodes Nematode Updates ­ Needle Nematodes on Wheat ­ 2 Potato Stalk Borer Stink Bug Western Bean Cutworm Entomologist: Winter Not Likely to Slow Corn Pest's Advance/Wild Onion Control in Wheat ­ 2 Marestail Control Essential to Protect Soybean Yields ­ 3 Poison Hemlock

Ginzel, Matthew

447

Ecological Setting of the Wind River Old-growth Forest  

E-print Network

annual precipitation, 2223 mm), 500-year-old Douglas-fir4 ­western hemlock forest of moderate to low-tolerant species. The Wind River old-growth forest fits the regional definition of Douglas-fir ``old growth

Franklin, Jerry

448

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

2013-10-01

449

Visit Us Again! 100 E. Northwestern Avenue  

E-print Network

Black walnut Canada hemlock Sourwood Eastern redbud Cockspur hawthorn Most trees can be easily seen from Arboretum Bender oak Chestnut oak Flowering dogwood Black tupelo Shagbark hickory American holly Cucumber.paflora.org #12;4 Black tupelo Nyssa sylvatica · Medium tree, to 90 feet, with a straight trunk and bark

Sharp, Kim

450

Bleach boosting and direct brightening by multiple xylanase treatments during peroxide bleaching of kraft pulps  

Microsoft Academic Search

The effects of multiple xylanase treatments were assessed during the peroxide bleaching of three pulps: Douglas-fir (kraft); Western hemlock (oxygen de- lignified kraft); and trembling Aspen (kraft). The addition of a xylanase treatment stage, either before or after the peroxide bleaching stage(s), resulted in the enhanced brightening of all pulps. A higher brightness was achieved using two enzyme treatments, one

Ken K. Y. Wong; Lori A. Martin; F. Miguel Gama; John N. Saddler; Ed de Jong

1997-01-01

451

Xylanase treatment for the peroxide bleaching of oxygen delignified kraft pulps derived from three softwood species  

Microsoft Academic Search

Three commercial enzymes were used to evaluate the use of xylanase treatment for enhancing the peroxide bleaching of three oxygen delignified kraft pulps derived from the softwoods red cedar, Douglas fir, and western hemlock. Two bleaching sequences were examined, where the enzyme stage was placed before or between the two peroxide stages. The brightness gain achieved was dependent on the

Ken K. Y. Wong; Sandra L. Nelson; John N. Saddler

1996-01-01

452

Responses to Green Leaf Volatiles in Two Biogeoclimatic Zones by Striped Ambrosia Beetle, Trypodendron lineatum  

Microsoft Academic Search

Experiments in the Coastal Western Hemlock (CWH) biogeoclimatic zone on the British Columbia (BC) coast and the Interior Douglas-fir (IDF) biogeoclimatic zone in the BC interior revealed pronounced differences in the effect of six-carbon green leaf volatiles on the response by striped ambrosia beetles, Trypodendron lineutum to multiple funnel traps baited with the aggregation pheromone lineatin. In the IDF zone,

J. H. Borden; L. J. Chong; A. Savoie; I. M. Wilson

1997-01-01

453

Diagenesis of conifer needles in a coastal marine environment  

NASA Astrophysics Data System (ADS)

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

Hedges, John I.; Weliky, K.

1989-10-01

454

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

NASA Astrophysics Data System (ADS)

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

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

2002-05-01

455

The Influence of Fire and Other Disturbance on Ericaceous Shrubs in Xeric Pine-Oak Forests of the Appalachian Mountains  

E-print Network

may perpetuate the existence and expansion of ericaceous shrubs. Although some canopy species such as Acer rubrum and Tsuga canadensis may be able to regenerate under dense shrub thickets it appears they are not, and Ericaceae seem to be self... 1976). 22 Fire suppression has resulted in increases in fire-intolerant species, such as Acer rubrum and Pinus strobus in forests previously dominated by yellow pines and Quercus spp. (Schowalter 1981; Harrod et.al. 1998; Aldrich et. al. 2010...

Pipkin, Ashley

2012-07-16

456

The mountain forests of british columbia and the american northwest: Floristic patterns and syntaxonomy  

Microsoft Academic Search

An overview of the montane and subalpine forests ofAbies lasiocarpa, Picea engelmannii, Abies amabilis andTsuga mertensiana of northwestern North America is provided based on 541 relevés of forest vegetation from coastal and inland British Columbia,\\u000a Washington and northwestern Montana. A new classification is proposed based on an examination of the floristic patterns across\\u000a these communities. Owing to their broadscale floristic

Toby Spribille

2002-01-01

457

Interspecific Variation in Tree Growth Response to 20th Century Climate Variability in the Circumpolar Boreal Forest  

Microsoft Academic Search

We examined relationships between tree ring-width and climate at 232 existing tree-ring sites around the circumpolar boreal forest (north of 55° N). The data set included ten common boreal species: Larix gmelinii, Larix sibirica, Picea abies, Picea glauca, Picea mariana, Picea obovata, Picea sitchensis, Pinus banksiana, Pinus sylvestris, Tsuga mertensiana. We used moving-window correlation analysis for eight 30-year time windows,

A. H. Lloyd; A. Bunn

2007-01-01

458

Latest Pleistocene and Holocene vegetation and climate history inferred from an alpine lacustrine record, northwestern Yunnan Province, southwestern China  

NASA Astrophysics Data System (ADS)

Reconstructing past changes of the summer monsoon in southwestern China is key to understanding the paleoclimatic dynamics of the Indian summer monsoon (southwest monsoon), a major tropical system with impacts beyond the region. High-resolution pollen and conifer stoma data are presented from a sediment core (Tiancai Lake), located just below treeline in the Hengduan Mountains, northwestern Yunnan Province of China. These data record changes in vegetation and climate for the latest Pleistocene and Holocene (c. the last 12,230 cal. yr BP), and by comparing these results with the pollen records from the nearby Erhai Lake and Lugu Lake, a regional climate history in Yunnan Province can be inferred. During the period of 12,230-11,510 cal. yr BP, open alpine meadow around Tiancai Lake indicates a relatively cold and dry climate, corresponding to the Younger Dryas cold event (YD). Between 11,510 and ˜10,000 cal. yr BP, the vegetation types around Tiancai Lake changed into Picea and Abies forest and alpine Rhododendron shrubland, reflecting increases in the temperature and humidity. From ˜10,000 to 6100 cal. yr BP, Tsuga forest expanded persistently toward Tiancai Lake, indicating further climate changed towards warmer and wetter conditions. Between 6100 and 3410 cal. yr BP, Tsuga forest was the dominant vegetation type nearest to Tiancai Lake, denoting warm and humid climatic conditions, corresponding to the Holocene climatic optimum in the northwestern Yunnan Province. Tsuga forest in mountains around Lugu Lake shrank quickly at 3410 cal. yr BP, reflecting significant decline of humidity. Since 2930 cal. yr BP, Tsuga forest around Tiancai Lake shrank gradually, indicating a fluctuating decrease of temperature. These climatic changes reflect changes of the southwest monsoon, namely, warm and humid climate indicating strong southwest monsoon, cold and dry climate denoting weak southwest monsoon.

Xiao, Xiayun; Haberle, Simon G.; Shen, Ji; Yang, Xiangdong; Han, Yong; Zhang, Enlou; Wang, Sumin

2014-02-01

459

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

NASA Astrophysics Data System (ADS)

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

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

2011-04-01

460

Studies on pigments, proteins and photosynthetic rates in some mangroves and mangrove associates from Bhitarkanika, Orissa  

Microsoft Academic Search

Pigment contents, proteins and net photosynthesis were investigated in fully developed leaf of 1-year-old seedlings of six mangroves (Bruguiera gymnorrhiza, Rhizophora apiculata) and mangrove associates (Caesalpinia bonduc, Cerbera manghas, Derris heterophylla, Thespesia populnea), collected from Bhitarkanika, located on the east coast of India. Large variations in the photosynthetic rates (PN) among the six species were observed, ranging from 10.16 µmol

A. Das; A. Parida; U. Basak; P. Das

2002-01-01

461

Plasmid-mediated transfer of nitrogen-fixing capability to bacteria from the rhizosphere of grasses  

Microsoft Academic Search

Cells of a non-nitrogen-fixing, drug-sensitive Enterobacter cloacae strain, isolated from the rhizosphere of Festuca heterophylla, were mated to Escherichia coli cells harboring plasmid pRD1. This plasmid carries the nitrogen-fixation (nif+) genes as well as three markers of drug resistance. After mating, triple-resistant Enterobacter transferants could be selected. These were screened for plasmids, acetylene reduction, and stability of the transferred markers.

A. Kleeberger; W. Klingmüller

1980-01-01

462

Sensitivity of mosses to sulfur dioxide  

Microsoft Academic Search

Seven North American moss species responded differentially to fumigations with sulfur dioxide ranging from 0.5 to 4.0 ppm. Leucobryum glaucum and Dicranum scoparium were the most sensitive species; Dicranella heterophylla, Polytrichum ohioense and Pottia truncata, the most resistant. The results of fumigations with 0.1 to 4.0 ppm sulfur dioxide for 8 hours on cultured gametophytes of Polytrichum ohioense indicate that

T. H. Nash; E. H. Nash

1974-01-01

463

Forest management and temporal effects on food abundance for a ground-foraging bird ( Catharus guttatus)  

Microsoft Academic Search

While food abundance is known to limit bird populations, few studies have simultaneously examined both temporal and habitat-related variation in food abundance for ground-foraging birds. We surveyed ground-dwelling arthropods throughout the breeding season and in three forest harvest types (clearcut, selection, and shelterwood stands managed for spruce, fir and hemlock) at the Penobscot Experimental Forest (PEF), Bradley, Maine, USA. Pitfall

Jason C. Johnston; Rebecca L. Holberton

2009-01-01

464

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

NASA Astrophysics Data System (ADS)

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

Johnson, A. C.; Mills, J.

2007-12-01

465

Ammonium sulfide organosolv pulping  

Microsoft Academic Search

The use of ammonium sulfide in aqueous ethanol and methanol was investigated for pulping of wood. Hemlock chips required 21% ammonium sulfide (equivalent to 19% Na2O) at 180°C to become delignified to the kappa range 35–50. The yields exceeded those of conventional kraft pulps by 14% on dry wood basis. Over 75% of the original glucomannan was recovered in the

V. L. Chiang; K. V. Sarkanen

1983-01-01

466

Characterization of soil organic matter in different particle-size fractions in humid subalpine soils by CP\\/MAS 13C NMR  

Microsoft Academic Search

The particle-size separation of subalpine soils was used for delineating the different functional C pools of soil organic matter (SOM) by solid-state cross-polarization\\/magic-angle-spinning (CP\\/MAS) 13C NMR spectroscopy. The soils collected from hemlock forest and dwarfed bamboo grassland along the slope positions at elevations from 2550 to 3200 m in central Taiwan, received high precipitation (>3000 mm). The obtained data show

Jenn-Shing Chen; Chih-Yu Chiu

2003-01-01

467

Effects of forest management practices on the diversity of ground-occurring beetles in mixed northern hardwood forests of the Great Lakes Region  

Microsoft Academic Search

Ground-occurring Coleoptera were sampled over 2 years using pitfall traps in 23 northern hardwood or eastern hemlock-dominated sites representing even-aged, uneven-aged, or old growth forests. Overall, 65,586 individuals were obtained, representing 33 families and 192 species. Carabids comprised 54% of the total catch in 1996, when all the families were tallied. There was little variation in the number and relative

Shahla M. Werner; Kenneth F. Raffa

2000-01-01

468

Ecosystem respiration and its components in an old-growth forest in the Great Lakes region of the United States  

Microsoft Academic Search

Ecosystem respiration and its components are sensitive to age, species, stand structure, and environmental conditions, and substantially influence net ecosystem productivity. We measured ecosystem respiration and component respiration including soil, woody debris, stem and leaf respiration in old-growth hardwood-dominated and hemlock-dominated stands in northern Michigan, USA in 2002 and 2003. Respiration was mainly controlled by temperature, peaked in July–August and

Jianwu Tang; Paul V. Bolstad; Ankur R. Desai; Jonathan G. Martin; Bruce D. Cook; Kenneth J. Davis; Eileen V. Carey

2008-01-01

469

Finding More Free Steam From Waste Heat  

E-print Network

Auburn, MI Hemlock, MI Midland, MI Barry, UK Wiesbaden, Germany St. Laurent du Pont, France Seneffe, Belgium Daman, India Zhangjiagang, China Songjiang, Shanghai, China Jincheon, South Korea Fukui, Japan Chiba, Japan Yamakita, Japan Komatsu, Japan... • Since THROx improvements have been completed, the 2014 energy cost savings are on track to be 4X greater than 2011 results. • Reductions in natural gas usage have allowed Midland site to apply for, and obtain $100,000 rebate from our local utility...

Stremlow, M. D.

2014-01-01

470

Woody tissue maintenance respiration of four conifers in contrasting climates  

Microsoft Academic Search

We estimate maintenance respiration for boles of four temperate conifers (ponderosa pine, western hemlock, red pine, and slash pine) from CO2 efflux measurements in autumn, when construction respiration is low or negligible. Maintenance respiration of stems was linearly related to sapwood volume for all species; at 10°C, respiration per unit sapwood volume ranged from 4.8 to 8.3 µmol CO2 m-3

Michael G. Ryan; Stith T. Gower; Robert M. Hubbard; Richard H. Waring; Henry L. Gholz; Wendell R Cropper Jr; Steven W. Running

1995-01-01

471

THE BREEDING BIOLOGY OF BROAD-WINGED  

Microsoft Academic Search

Nesting Red-shouldered (Buteo lineatus; RSH) and Broad-winged Hawks (Buteo platypterus; BWH) were studied in 1978-1980 in Chautauqua County, New York. Both species nested predominantly in upland maple-beech-hemlock associations. Six of 18 BWH nests were in larch (Larix decidua); 7 of 18 RSH nests were in American beech (Fagus grandifolia). BWH nested closer to woodland openings and lower in a tree

SCOTT T. CROGOLL; JAMES W. PARKER

472

Diatom Records of Holocene Environmental and Climatic Change in Southeastern British Columbia  

NASA Astrophysics Data System (ADS)

The sediments of three lakes, spanning a latitudinal gradient and situated within the Interior Cedar-Hemlock biogeoclimatic zone of southeast British Columbia, have been analyzed for independent records of Holocene climate and vegetation history in order to evaluate the role of climate as a control on range expansion of western hemlock and western redcedar. Holocene climate reconstructions are based on multiple proxies, including the diatom and biogenic silica stratigraphies presented here. To our knowledge, these sites provide the first continuous Holocene paleoecological and paleoclimatic records from the region between the Interior Plateau and the Rocky Mountains. Stratigraphic variability in the diatom sedimentary records reflects lake response to changes in water balance, catchment development, and atmospheric inputs of silica (i.e. volcanic ash). At Eleanor Lake, the diatom record shows significant assemblage shifts at ˜7500, 6300, and 3700 cal yr BP. Increased abundance of planktonic and tychoplanktonic diatoms and an increase in the abundance of chrysophyte cysts relative to diatoms at 6300 cal yr BP is consistent with an increase in effective moisture at this time. At Mirror Lake, in the south, an assemblage dominated by small benthic species is replaced by a predominantly planktonic assemblage at 6900 cal yr BP, suggesting an earlier increase in lake level. After 6000 cal yr BP, planktonic diatoms further increase in dominance. These dates are consistent with reconstructions of Holocene climate in south-central British Columbia, which suggest a shift to moister conditions ca. 7000 to 6000 cal yr BP. The pollen record indicates the expansion of western hemlock and western redcedar near Mirror Lake at 3550 cal yr BP and 3250 cal yr BP respectively. At Eleanor Lake, hemlock expansion is dated at 4350 cal yr BP. The data indicate a difference of 1950 to > 3000 years between the lacustrine record of increased effective moisture and the vegetation response and suggest that non-climatic factors played a significant role in the Holocene range expansion of these trees.

Westover, K. S.; Gavin, D. G.; Fritz, S. C.; Hu, F.; Roschen, L. A.

2004-12-01

473

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

USGS Publications Warehouse

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

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

2010-01-01

474

Polyploidy and variation in the Campanula rotundifolia complex. Part II. (Taxonomic) I. Revision of the groups Saxicolae, Lanceolatae and Alpicolae in Czechoslovakia and adjacent regions  

Microsoft Academic Search

A survey is given of three natural groups of the subsectionHeterophylla (Witas.)Fed. of the genusCampanula L. Within theSaxicolae four taxa of higher rank have been revealed:c. xylocarpa\\u000a Kovanda (2n=34),C. gentilis\\u000a Kovanda (2n=34),C. moravica (Spitzner)Kovanda subsp.moravica (2n=68), andC. moravica subsp.xylorrhiza (O. Schwarz)Kovanda (2n=102). BothAlpicolae andLanceolatae are represented by a single species: the first byC. cochleariifolia\\u000a Lam. (2n=34), the latter byC. serrata

Miloslav Kovanda

1970-01-01

475

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

NASA Astrophysics Data System (ADS)

Whole green, litter, and sedimentary fir, hemlock, and cedar needles and bulk sediments collected from the Dabob Bay region in Washington state were analyzed for their cutin-derived CuO reaction products. All samples yielded dihydroxyhexadecanoic acid isomers (x,?-C 16), 16-hydroxyhexa-decanoic acid (?-C 16), 14-hydroxytetradecanoic acid (?-C 14), and 18-hydroxyoctadec-9-enoic acid (?-C 18: 1) as the major cutin acids. Fir/hemlock needle mixtures were characterized by a high abundance of the 9,16-dihydroxyhexadecanoic acid positional isomer, while cedar needles produced primarily the 10,16-dihydroxy counterpart. Cutin acids accounted for ~3% of tissue C in green needles, ~4% in needle litter, 0.5-1.5% in sedimentary needles, and about 0.1% of the organic carbon (OC) in bulk sediments. Approximately 80% of the original cutin acids in fresh green needles were lost from the deepest (~100 years old) sedimentary tissues. Cutin was more reactive than lignin and polysaccharides, but more stable than the cyclitol components of the same needles. Comparative diagenetic losses of the individual cutin acids were not uniform and suggest that additional hydroxy groups and the presence of C double bonds both increase overall reactivity. The relative stability series derived for all the molecular constituents measured is: total vanillyl phenols > total P- hydroxy phenols, ferulic acid, most aldoses, bulk organic matter > mannose, ?-C 14, ?-C 16 ? ?-C 18:1 > glucose, p- coumaric acid, x, ?-C 16 > all cyclitols. Diagenetically induced changes in the various cutin parameters used to characterize nonwoody vascular plant tissues were not large enough to confuse degraded conifer tissues with other cutin sources. Based on these trends, the finely disseminated cutin-bearing tissues in Dabob Bay sediments appear to be comprised approximately of equal amounts of highly degraded fir/hemlock and cedar needle fragments. According to this estimate, nonwoody vascular plant debris accounted for roughly 15% of the total organic matter present in these sediments.

Goñi, Miguel A.; Hedges, John I.

1990-11-01

476

Operational experience at a `dog-hair` site. Forest Service research note  

SciTech Connect

The authors installed plots in a nine-year-old Douglas-fir plantation established after clearcutting a grossly overstocked stand. One plot sampled the slash-burned portion. In the nonburned portion, two plots were in areas thinned three years earlier by machete combined with pulling small seedlings, and four were in areas thinned by chainsaw. Stumps with sprouts averaged 5,665 per acre in saw-thinned plots and only 250 per acre in plots thinned by machete and pulling. Most seedlings and sprouts were western hemlock. Machete cutting and pulling proved more effective than chainsaws for reducing stem density. Slash burning destroyed most new seedlings.

Ricketts, S.R.; Miller, R.E.

1995-04-01

477

Forest Ecology  

NSDL National Science Digital Library

This tutorial discusses the concept of forest succession, the stages of development which forest plants follow as they grow or re-grow following an event such as a forest fire or insect infestation. Topics include the role of pioneer species, the transition to longer-lived plants such as lodgepole pine, Douglas fir, and subalpine fir, and the transition to climax species such as cedars, hemlocks and spruce. There is also a discussion of the lifespan of climax forests and the wildlife species that inhabit the forest in each stage of succession. A quiz and glossary are provided.

478

Forest Age and Relative Abundance of Pileated Woodpeckers on Southeastern Vancouver Island 1  

E-print Network

We estimated relative abundance of the pileated woodpeckers (Dryocopus pileatus) at four sites in the Coastal Western Hemlock Biogeoclimatic zone, on southeastern Vancouver Island during 1996-1997. The number of pileated woodpecker calls was correlated with age and structure of forests. Pileated woodpeckers did not use intensively managed forests 140-year-old stands. However, their abundance in these forests did not differ significantly from that in early seral forests (49 percent> 80-year-old stands) or old forests (70 percent> 140-year-old stands).

Carol L. Hartwig; Donald S. Eastman; Alton S. Harestad

479

A streptomycete antagonist to Phellinus weirii, Fomes annosus, and Phytophthora cinnamomi.  

PubMed

An actinomycete isolated from the rhizoplane of nitrogen-fixing nodules of Ceanothus velutinus was identified as a variety of Streptomyces griseoloalbus. Streptomyces griseoloalbus is a strong antagonist to three destructive root pathogens, Phellinus weirii, Fomes annosus, and Phytophthora cinnamomi, inhibiting all three on several culture media and preventing establishment of F. annosus on hemlock wood disks. The stability and longevity of the antimicrobial substance produced by it, its consistent effect on the pathogens on all substrates, its ability to colonize wood, and its ability to grow at 10 degrees C suggest biological control possibilities for this organism in the Pacific Northwest. PMID:7397603

Rose, S L; Li, C Y; Hutchins, A S

1980-05-01

480

Herbivore-induced expansion of generalist species as a driver of homogenization in post-disturbance plant communities  

Microsoft Academic Search

We used a controlled experiment to investigate how disturbance scale (canopy gap area) and herbivory influence post-disturbance\\u000a plant community dynamics. Twenty canopy gaps were installed in a temperate hemlock-hardwood forest during the winter of 2002–2003:\\u000a seven small gaps (50–150 m2), seven medium gaps (151–250 m2), and six large gaps (251–450 m2). Within each gap, we established 4–12 sample plots (depending on gap size);

Stacie A. Holmes; Christopher R. Webster

2011-01-01