Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| molecular characterization of fusarium oxysporum and fusarium commune isolates from a conifer nursery. | abstract fusarium species can cause severe root disease and damping-off in conifer nurseries. fusarium inoculum is commonly found in most container and bareroot nurseries on healthy and diseased seedlings, in nursery soils, and on conifer seeds. isolates of fusarium spp. can differ in virulence; however, virulence and colony morphology are not correlated. forty-one isolates of fusarium spp., morphologically indistinguishable from f. oxysporum, were collected from nursery samples (soils, healthy ... | 2006 | 18943501 |
| bordered pit structure and function determine spatial patterns of air-seeding thresholds in xylem of douglas-fir (pseudotsuga menziesii; pinaceae) trees. | the air-seeding hypothesis predicts that xylem embolism resistance is linked directly to bordered pit functioning. we tested this prediction in trunks, roots, and branches at different vertical and radial locations in young and old trees of pseudotsuga menziesii. dimensions of bordered pits were measured from light and scanning electron micrographs, and physiological data were from published values. consistent with observations, calculations showed that earlywood tracheids were more resistant to ... | 2006 | 21642104 |
| host-pathogen interactions in douglas-fir seedlings infected by phellinus sulphurascens. | abstract several aspects of the host-pathogen interaction between douglas-fir (pseudotsuga menziesii) and the fungal pathogen phellinus sulphurascens were investigated in an in vitro inoculation system using young seedlings and fungal mycelia. light microscopy confirmed that p. sulphurascens mycelia can successfully penetrate host epidermal cells within 3 days postinoculation (dpi). extensive fungal colonization and cortical cell decay occurred within 14 dpi. western immunoblot studies showed si ... | 2007 | 18943509 |
| multiple resonance damping or how do trees escape dangerously large oscillations? | to further understand the mechanics of trees under dynamic loads, we recorded damped oscillations of a douglas fir (pseudotsuga menziesii) tree and of its stem without branches. eigenfrequencies of the branches were calculated and compared to the oscillation frequency of the intact tree. the term eigenfrequency is used here to characterize the calculated resonance frequency of a branch fixed at the proximal end to a solid support. all large branches had nearly the same frequency as the tree. thi ... | 2007 | 21636359 |
| developmental decline in height growth in douglas-fir. | the characteristic decline in height growth that occurs over a tree's lifespan is often called "age-related decline." but is the reduction in height growth in aging trees a function of age or of size? we grafted shoot tips across different ages and sizes of douglas-fir (pseudotsuga menziesii (mirb.) franco) trees to determine whether the decline in height growth is mediated by tree size or by the age of the apical meristem. we also evaluated whether reduced carbon assimilation plays an important ... | 2007 | 17241986 |
| tree proximity, soil pathways and common mycorrhizal networks: their influence on the utilization of redistributed water by understory seedlings. | hydraulic redistribution (hr) is a process by which water moves through plant roots from moist to dry soils. an experiment was conducted to quantify the influence of common mycorrhizal networks (cmns) and proximity to mature hr-source trees on the water relations of surrounding seedlings. douglas-fir (pseudotsuga menziesii var glauca (mirb.) franco) seedlings were planted at four distances (0.5, 1, 2.5, and 5 m) from six mature douglas-fir trees, either directly into soil (soil plus cmn pathway) ... | 2007 | 17885766 |
| elevated co(2) and temperature alter net ecosystem c exchange in a young douglas fir mesocosm experiment. | we investigated the effects of elevated co(2) (ec) [ambient co(2) (ac) + 190 ppm] and elevated temperature (et) [ambient temperature (at) + 3.6 degrees c] on net ecosystem exchange (nee) of seedling douglas fir (pseudotsuga menziesii) mesocosms. as the study utilized seedlings in reconstructed soil-litter-plant systems, we anticipated greater c losses through ecosystem respiration (r(e)) than gains through gross photosynthesis (gpp), i.e. negative nee. we hypothesized that: (1) ec would increase ... | 2007 | 17897410 |
| antimicrobial activity of extractable conifer heartwood compounds toward phytophthora ramorum. | ethyl acetate extracts from heartwood of seven western conifer trees and individual volatile compounds in the extracts were tested for antimicrobial activity against phytophthora ramorum. extracts from incense and western redcedar exhibited the strongest activity, followed by yellow-cedar, western juniper, and port-orford-cedar with moderate activity, and no activity for douglas-fir and redwood extracts. chemical composition of the extracts varied both qualitatively and quantitatively among the ... | 2007 | 17929093 |
| changes in net ecosystem productivity with forest age following clearcutting of a coastal douglas-fir forest: testing a mathematical model with eddy covariance measurements along a forest chronosequence. | we hypothesized that changes in net ecosystem productivity (nep) during aging of coastal douglas-fir (pseudotsuga menziesii mirb. franco) stands could be explained by (1) changing nutrient uptake caused by different time scales for decomposition of fine, non-woody and coarse woody litter left after harvesting, (2) declines in canopy water status with lengthening of the water uptake pathway during bole and branch growth, and (3) increases in the ratio of autotrophic respiration (r (a)) to gross p ... | 2007 | 17169913 |
| development and evaluation of methods to detect nucleopolyhedroviruses in larvae of the douglas-fir tussock moth, orgyia pseudotsugata (mcdunnough). | various molecular methods are used to detect pathogenic microorganisms and viruses within their hosts, but these methods are rarely validated by direct comparison. southern hybridization, enzyme-linked immunosorbent assay (elisa), and a novel dna extraction/pcr assay were used to detect orgyia pseudotsugata multiple nucleopolyhedrovirus (opmnpv) in douglas-fir tussock moth larvae. pcr was more sensitive than southern hybridization and elisa at detecting semipurified virus. elisa, however, was th ... | 2007 | 17189436 |
| mapping the environmental limitations to growth of coastal douglas-fir stands on vancouver island, british columbia. | coastal douglas-fir (pseudotsuga menziesii spp. menziesii (mirb.) franco) occurs over a wide range of environmental conditions on vancouver island, british columbia. although ecological zones have been drawn, no formal spatial analysis of environmental limitations on tree growth has been carried out. such an exercise is desirable to identify areas that may warrant intensive management and to evaluate the impacts of predicted climate change this century. we applied a physiologically based forest ... | 2007 | 17331899 |
| design of highly efficient cellulase mixtures for enzymatic hydrolysis of cellulose. | an extremely highly active cellobiohydrolase (cbh iib or cel6b) was isolated from chrysosporium lucknowense uv18-25 culture filtrate. the cbh iib demonstrated the highest ability for a deep degradation of crystalline cellulose amongst a few cellobiohydrolases tested, including c. lucknowense cbh ia, ib, iia, and trichoderma reesei cbh i and ii. using purified c. lucknowense enzymes (cbh ia, ib, and iib; endoglucanases ii and v; beta-glucosidase, xylanase ii), artificial multienzyme mixtures were ... | 2007 | 17221887 |
| tree water storage and its diurnal dynamics related to sap flow and changes in stem volume in old-growth douglas-fir trees. | diurnal and seasonal tree water storage was studied in three large douglas-fir (pseudotsuga menziesii [mirb.] franco) trees at the wind river canopy crane research site. changes in water storage were based on measurements of sap flow and changes in stem volume and tissue water content at different heights in the stem and branches. we measured sap flow by two variants of the heat balance method (with internal heating in stems and external heating in branches), stem volume with electronic dendrome ... | 2007 | 17241961 |
| species richness and community composition of mat-forming ectomycorrhizal fungi in old- and second-growth douglas-fir forests of the hj andrews experimental forest, oregon, usa. | we investigated the species identity of mat-forming ectomycorrhizal (em) fungi associated with old- and second-growth douglas-fir stands. using molecular analyses of rhizomorphs and em root tips, we characterized 28 unique internal transcribed spacer sequences and considered them proxies for mat-forming em species. in both stand age classes, one athelioid species in the genus piloderma dominated our sample of the mat-forming fungal community. in second-growth stands, the second most frequently e ... | 2007 | 17638027 |
| dynamic variation in sapwood specific conductivity in six woody species. | our goals were to quantify how non-embolism-inducing pressure gradients influence trunk sapwood specific conductivity (k(s)) and to compare the impacts of constant and varying pressure gradients on k(s) with kcl and h2o as the perfusion solutions. we studied six woody species (three conifers and three angiosperms) which varied in pit membrane structure, pit size and frequency of axial water transport across pits (long versus short conduits). both stepwise ("steady") and nonlinear continuous ("no ... | 2007 | 17669729 |
| impacts of tree height on leaf hydraulic architecture and stomatal control in douglas-fir. | this study investigated the mechanisms involved in the regulation of stomatal closure in douglas-fir and evaluated the potential impact of compensatory adjustments in response to increasing tree height upon these mechanisms. in the laboratory, we measured leaf hydraulic conductance (k(leaf)) as leaf water potential (psi(l)) declined for comparison with in situ diurnal patterns of stomatal conductance (g(s)) and psi(l) in douglas-fir across a height gradient, allowing us to infer linkages between ... | 2007 | 17407534 |
| using nocturnal cold air drainage flow to monitor ecosystem processes in complex terrain. | this paper presents initial investigations of a new approach to monitor ecosystem processes in complex terrain on large scales. metabolic processes in mountainous ecosystems are poorly represented in current ecosystem monitoring campaigns because the methods used for monitoring metabolism at the ecosystem scale (e.g., eddy covariance) require flat study sites. our goal was to investigate the potential for using nocturnal down-valley winds (cold air drainage) for monitoring ecosystem processes in ... | 2007 | 17494390 |
| radial patterns of carbon isotopes in the xylem extractives and cellulose of douglas-fir. | heartwood extractives (nonstructural wood components) are believed to be formed from a combination of compounds present in the adjacent sapwood and materials imported from the phloem. the roles of local compounds and imported material in heartwood formation could have important implications for the wood quality of species having naturally durable wood. stable isotope composition (delta(13)c) was analyzed to assess radial variation in sapwood extractives, and to estimate the relative importance o ... | 2007 | 17331910 |
| water transfer via ectomycorrhizal fungal hyphae to conifer seedlings. | little is known about water transfer via mycorrhizal hyphae to plants, despite its potential importance in seedling establishment and plant community development, especially in arid environments. therefore, this process was investigated in the study reported in this paper in laboratory-based tripartite mesocosms containing the shrub arctostaphylos viscida (manzanita) and young seedlings of sugar pine (pinus lambertiana) and douglas-fir (pseudotsuga menziesii). the objectives were to determine wh ... | 2007 | 17333298 |
| ectomycorrhizal fungi associated with ponderosa pine and douglas-fir: a comparison of species richness in native western north american forests and patagonian plantations from argentina. | the putative ectomycorrhizal fungal species registered from sporocarps associated with ponderosa pine and douglas-fir forests in their natural range distribution (i.e., western canada, usa, and mexico) and from plantations in south argentina and other parts of the world are listed. one hundred and fifty seven taxa are reported for native ponderosa pine forests and 514 taxa for native douglas-fir forests based on available literature and databases. a small group of genera comprises a high proport ... | 2007 | 17345105 |
| outbreak of lepidopterism at a boy scout camp. | lepidopterism refers to moth- or butterfly-associated illness, including contact dermatitis, urticaria, and occasional systemic reactions. lepidopterism outbreaks are rare. | 2007 | 17368636 |
| species-specific partitioning of soil water resources in an old-growth douglas-fir-western hemlock forest. | 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 dep ... | 2007 | 17331905 |
| evaluating the distribution of cellulases and the recycling of free cellulases during the hydrolysis of lignocellulosic substrates. | the recycling of cellulase enzymes is one potential strategy for reducing the cost of the enzymatic hydrolysis step during the bioconversion of lignocellulosics to ethanol. to determine the influence of lignin on the post-hydrolysis distribution of cellulase enzymes between the liquid and solid phases, the hydrolysis of avicel was compared to an organosolv-pretreated douglas fir substrate with a lignin content of 3.0%. after a 12 h hydrolysis reaction on avicel, 90% of the added cellulases (incl ... | 2007 | 17378581 |
| metabolite profiling of douglas-fir (pseudotsuga menziesii) field trials reveals strong environmental and weak genetic variation. | the primary objective of this study was to assess metabolomics for its capacity to discern biological variation among 10 full-sib families of a douglas-fir tree breeding population, replicated on two sites. the differential accumulation of small metabolites in developing xylem was examined through metabolite profiles (139 metabolites common to 181 individual trees) generated by gas chromatography mass spectrometry and a series of statistical analyses that incorporated family, site, and tree grow ... | 2007 | 17504460 |
| impact of ectomycorrhizosphere on the functional diversity of soil bacterial and fungal communities from a forest stand in relation to nutrient mobilization processes. | the ectomycorrhizal symbiosis alters the physicochemical and biological conditions in the surrounding soil, thus creating a particular environment called ectomycorrhizosphere, which selects microbial communities suspected to play a role in gross production and nutrient cycling. to assess the ectomycorrhizosphere effect on the structure of microbial communities potentially involved in the mobilization of nutrients from the soil minerals in a poor-nutrient environment, we compared the functional d ... | 2007 | 17546519 |
| fire resistance of douglas fir (pseudotsuga menzieesi) treated with borates and natural extractives. | the objective of this study was to determine fire resistance of douglas fir (pseudotsuga menzieesi (mirb.) franco) specimens treated with borate supplemented aqueous solutions of brutia pine bark powder, acorn powder, sumach leaf powder, and gall-nut powder. boric acid (ba) and borax (bx) were used as borates which are the most commonly used fire retardants in wood preservation industry. natural extractives (brutia pine bark powder, sumach leaf powder, acorn powder, and gall-nut powder) were als ... | 2007 | 16822670 |
| family variation in nutritional and growth traits in douglas-fir seedlings. | nitrogen (n) uptake and utilization in seedlings of six full-sib families of coastal douglas fir (pseudotsuga menziesii (mirb.) franco) known to differ in growth rate were assessed at the whole plant and root levels. seedlings were grown in soil or aeroponically with high and low nutrient availability. consistent family differences in growth rate and n utilization index were observed in both soil and aeroponic culture, and high-ranking families by these measures also had greater net n uptake in ... | 2007 | 17331909 |
| bole water content shows little seasonal variation in century-old douglas-fir trees. | purportedly, large douglas-fir trees in the american pacific northwest use water stored in bole tissues to ameliorate the effects of seasonal summer drought, the water content of bole tissues being drawn down over the summer months and replenished during the winter. continuous monitoring of bole relative water content (rwc) in two 110-120-year-old douglas-fir trees with thetaprobe impedance devices provided an integrated measure of phloem-sapwood water content over 4 years. seasonal changes in r ... | 2007 | 17267364 |
| hydraulic redistribution of soil water in two old-growth coniferous forests: quantifying patterns and controls. | although hydraulic redistribution of soil water (hr) by roots is a widespread phenomenon, the processes governing spatial and temporal patterns of hr are not well understood. we incorporated soil/plant biophysical properties into a simple model based on darcy's law to predict seasonal trajectories of hr. we investigated the spatial and temporal variability of hr across multiple years in two old-growth coniferous forest ecosystems with contrasting species and moisture regimes by measurement of so ... | 2007 | 17286824 |
| ethnoveterinary medicines used for ruminants in british columbia, canada. | the use of medicinal plants is an option for livestock farmers who are not allowed to use allopathic drugs under certified organic programs or cannot afford to use allopathic drugs for minor health problems of livestock. | 2007 | 17324258 |
| ectomycorrhizal fungal succession in mixed temperate forests. | ectomycorrhizal (ecm) fungal communities of douglas-fir (pseudotsuga menziesii) and paper birch (betula papyrifera) were studied along a chronosequence of forest development after stand-replacing disturbance. previous studies of ecm succession did not use molecular techniques for fungal identification or lacked replication, and none examined different host species. four age classes of mixed forests were sampled: 5-, 26-, 65-, and 100-yr-old, including wildfire-origin stands from all four classes ... | 2007 | 17888121 |
| the systematic position of phaeocryptopus gaeumannii. | phaeocryptopus gaeumannii, causal agent of the douglas-fir foliar disease swiss needle cast, is the only known pathogenic species of the genus. current classifications place phaeocryptopus in the venturiaceae (pleosporales), typified by the apple-scab pathogen venturia inaequalis. all core members of this family have hyphomycetous anamorphs. we sought to confirm these relationships by means of phylogenetic analyses of the small (ssu) and large (lsu) subunits and internal transcribed spacer (its) ... | 2007 | 17682777 |
| development of a dipstick immunoassay to detect nucleopolyhedroviruses in douglas-fir tussock moth larvae. | in this paper, we describe the development of a novel field detection system for the identification of orgyia pseudotsugata nucleopolyhedrovirus (opnpv) and opnpv infections in douglas-fir tussock moth (o. pseudotsugata) (dftm) larvae, utilizing antibodies in a dipstick immunoassay. the dipstick method is sensitive to a minimum of 10ng of extracted virus protein, or approximately 1070 virus occlusion bodies, and is sufficiently sensitive to detect opnpv infections in dftm prior to mortality. add ... | 2007 | 17706298 |
| synergistic effect of heartwood extractives and quaternary ammonium compounds on termite resistance of treated wood. | 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 t ... | 2007 | 17054087 |
| aminocyclopropane carboxylic acid synthase is a regulated step in ethylene-dependent induced conifer defense. full-length cdna cloning of a multigene family, differential constitutive, and wound- and insect-induced expression, and cellular and subcellular localization in spruce and douglas fir. | in conifer stems, formation of chemical defenses against insects or pathogens involves specialized anatomical structures of the phloem and xylem. oleoresin terpenoids are formed in resin duct epithelial cells and phenolics accumulate in polyphenolic parenchyma cells. ethylene signaling has been implicated in the induction of these chemical defenses. recently, we reported the cloning of 1-aminocyclopropane-1-carboxylic acid oxidase (aco) from spruce (picea spp.) and douglas fir (pseudotsuga menzi ... | 2007 | 17122070 |
| hydraulic architecture and photosynthetic capacity as constraints on release from suppression in douglas-fir and western hemlock. | 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-ye ... | 2007 | 17169904 |
| using automated flight mills to manipulate fat reserves in douglas-fir beetles (coleoptera: curculionidae). | because current techniques for quantifying fat, the main fuel used for flight in insects, are destructive, researchers are limited to only one direct measure of fat per specimen. this limitation is problematic for studies aimed at assessing whether fat loss through flight influences subsequent behavioral activity. to overcome this problem, we used body volume, body mass, emergence day, and brood density as parameters in a multiple regression model to predict initial fat levels in female douglas- ... | 2008 | 18801248 |
| carbon balance of conifer seedlings at timberline: relative changes in uptake, storage, and utilization. | low rates of growth for conifers at high elevations may relate to problems in acquiring or utilizing carbon. a traditional hypothesis for growth limits of trees at alpine treeline is that low photosynthesis (a) leads to insufficient supply of carbon for growth. alternatively, the sink-limitation hypothesis questions the importance of low a, and suggests that trees at treeline have abundant carbon for growth as a result of greater decreases in carbon use [respiration (r) and growth] than a at hig ... | 2008 | 18810499 |
| patterns of divergence among conifer ests and polymorphism in pinus sylvestris identify putative selective sweeps. | finding genes that are under positive selection is a difficult task, especially in non-model organisms. here, we have analyzed expressed sequence tag (est) data from 4 species (pinus pinaster, pinus taeda, picea glauca, and pseudotsuga menziesii) to investigate selection patterns during their evolution and to identify genes likely to be under positive selection. to confirm selection, population samples of these genes have been sequenced in pinus sylvestris, a species that was not included in the ... | 2008 | 18775901 |
| plfa profiling of microbial community structure and seasonal shifts in soils of a douglas-fir chronosequence. | the impact and frequency of forest harvesting could significantly affect soil microbial community (smc) structure and functioning. the ability of soil microorganisms to perform biogeochemical processes is critical for sustaining forest productivity and has a direct impact on decomposition dynamics and carbon storage potential. the wind river canopy crane research forest in sw, wa, provided a unique opportunity to study a forest chronosequence and the residual effects of harvesting on the smc in ... | 2008 | 17786504 |
| molecular analysis of bacterial communities associated with the roots of douglas fir (pseudotsuga menziesii) colonized by different ectomycorrhizal fungi. | we studied the effect of ectomycorrhizal fungi on bacterial communities colonizing roots of douglas fir (pseudotsuga menziesii). mycorrhizal tips were cleaned of soil and separated based on gross morphological characteristics. sequencing of the internal transcribed spacers of the nuclear rrna gene cluster indicated that the majority of the tips were colonized by fungi in the russulaceae, with the genera russula and lactarius comprising 70% of the tips. because coamplification of organellar 16s r ... | 2008 | 18459969 |
| colonization and decomposition of salal (gaultheria shallon) leaf litter by saprobic fungi in successional forests on coastal british columbia. | the colonization of leaf litter by saprobic fungi was studied in old-growth and post-harvest successional douglas-fir forests on southeast vancouver island, british columbia. this study focused on leaf litter of salal (gaultheria shallon pursh.), a dominant understory shrub in all stands. salal litter is characterized by the occurrence of bleached portions attributable to fungal colonization of the litter and to the variable decomposition of recalcitrant compounds, such as lignin. analyses of pr ... | 2008 | 18535627 |
| suitability of pines and other conifers as hosts for the invasive mediterranean pine engraver (coleoptera: scolytidae) in north america. | the invasive mediterranean pine engraver, orthotomicus erosus (wollaston) (coleoptera: scolytidae), was detected in north america in 2004, and it is currently distributed in the southern central valley of california. it originates from the mediterranean region, the middle east, and asia, and it reproduces on pines (pinus spp.). to identify potentially vulnerable native and adventive hosts in north america, no-choice host range tests were conducted in the laboratory on 22 conifer species. the bee ... | 2008 | 18613584 |
| community composition of ammonia-oxidizing bacteria and archaea in soils under stands of red alder and douglas fir in oregon. | this study determined nitrification activity and nitrifier community composition in soils under stands of red alder (alnus rubra) and douglas fir (pseudotsuga menziesii) at two sites in oregon. the h.j. andrews experimental forest, located in the cascade mountains of oregon, has low net n mineralization and gross nitrification rates. cascade head experimental forest, in the coast range, has higher net n mineralization and nitrification rates and soil ph is lower. communities of putative bacteria ... | 2008 | 18393992 |
| modelling environmental controls on ecosystem photosynthesis and the carbon isotope composition of ecosystem-respired co2 in a coastal douglas-fir forest. | we developed and applied an ecosystem-scale model that calculated leaf co2 assimilation, stomatal conductance, chloroplast co2 concentration and the carbon isotope composition of carbohydrate formed during photosynthesis separately for sunlit and shaded leaves within multiple canopy layers. the ecosystem photosynthesis model was validated by comparison to leaf-level gas exchange measurements and estimates of ecosystem-scale photosynthesis from eddy covariance measurements made in a coastal dougl ... | 2008 | 18182019 |
| simulating the dynamic behavior of douglas-fir trees under applied loads by the finite element method. | the finite element method of structural analysis was used to model the dynamic behavior of three 20-year-old douglas-fir (pseudotsuga menziesii (mirb.) franco) trees subjected to applied loading. detailed measurements of stem and branch geometry were made for each tree, enabling the first-order branches of each tree to be represented as individual cantilever beams attached to the stem. three values for branch modulus of elasticity (e) were assumed: 4, 5 and 6 gpa. for two trees with relatively l ... | 2008 | 17938116 |
| a comparison of ammonium, nitrate and proton net fluxes along seedling roots of douglas-fir and lodgepole pine grown and measured with different inorganic nitrogen sources. | significant spatial variability in nh4+, no3- and h+ net fluxes was measured in roots of young seedlings of douglas-fir (pseudotsuga menziesii) and lodgepole pine (pinus contorta) with ion-selective microelectrodes. seedlings were grown with nh4+, no3-, nh4no3 or no nitrogen (n), and were measured in solutions containing one or both n ions, or no n in a full factorial design. net no3- and nh4+ uptake and h+ efflux were greater in douglas-fir than lodgepole pine and in roots not exposed to n in p ... | 2008 | 18034773 |
| biophysical constraints on leaf expansion in a tall conifer. | the physiological mechanisms responsible for reduced extension growth as trees increase in height remain elusive. we evaluated biophysical constraints on leaf expansion in old-growth douglas-fir (pseudotsuga menziesii (mirb.) franco) trees. needle elongation rates, plastic and elastic extensibility, bulk leaf water (psi(l)) and osmotic (psi(pi)) potential, bulk tissue yield threshold and final needle length were characterized along a height gradient in crowns of > 50-m-tall trees during the peri ... | 2008 | 18055430 |
| phytohormones and their metabolites during long shoot development in douglas-fir following cone induction by gibberellin injection. | changes in plant hormones and metabolites in long-shoot stems of interior douglas-fir (pseudotsuga menziesii var. glauca (beissn.) franco) during cone induction by gibberellic acid (ga) treatment were analyzed by high performance liquid chromatography-electrospray ionization tandem mass spectrometry in multiple reaction monitoring mode. a mixture of ga(4) and ga(7), including small amounts of ga(3) and ga(1), was stem-injected into each tree in amounts of 0, 4, 40 or 400 mg. one week after injec ... | 2008 | 18595848 |
| a proteomics approach to identify proteins differentially expressed in douglas-fir seedlings infected by phellinus sulphurascens. | we carried out a comparative proteomic study to explore the molecular mechanisms that underlie the defense response of douglas-fir (df, pseudotsuga menziesii) to laminated root rot, a disease caused by phellinus sulphurascens. 2-de was conducted on proteins extracted from roots of laboratory-grown, young df seedlings inoculated with p. sulphurascens. a total of 1303 proteins was detected in 7 dpi infected and uninfected root samples. among these 1303 proteins, 277 showed differential expression ... | 2008 | 18602030 |
| high release rate 3-methylcyclohex-2-en-1-one dispensers prevent douglas-fir beetle (coleoptera: curculionidae) infestation of live douglas-fir. | the douglas-fir beetle, dendroctonus pseudotsugae hopkins (coleoptera: curculionidae), antiaggregation pheromone, 3-methylcyclohex-2-en-1-one (mch), has been used by natural resource managers and landowners to protect high-value, high-risk trees from douglas-fir beetle infestation throughout the western united states since 2000. labor is a major portion of the cost of mch treatments. mch is applied by walking through treatment areas and stapling the formulated pheromone in bubble capsules to tre ... | 2008 | 19133463 |
| flux partitioning in an old-growth forest: seasonal and interannual dynamics. | 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 hetero ... | 2008 | 18244938 |
| effects of mutual shading of tree crowns on prediction of photosynthetic light-use efficiency in a coastal douglas-fir forest. | gross primary production (gpp) is often expressed as the product of absorbed photosynthetically active radiation and the efficiency (epsilon) with which a plant community uses absorbed radiation in biomass production. light-use efficiency is affected by environmental stresses, and varies diurnally and seasonally. uncertainty about epsilon can be a serious limitation when modeling gpp. an important determinant of epsilon is the amount and type of solar radiation incident on a canopy, because an a ... | 2008 | 18381263 |
| the influence of the ectomycorrhizal fungus rhizopogon subareolatus on growth and nutrient element localisation in two varieties of douglas fir (pseudotsuga menziesii var. menziesii and var. glauca) in response to manganese stress. | acidification of forest ecosystems leads to increased plant availability of the micronutrient manganese (mn), which is toxic when taken up in excess. to investigate whether ectomycorrhizas protect against excessive mn by improving plant growth and nutrition or by retention of excess mn in the hyphal mantle, seedlings of two populations of douglas fir (pseudotsuga menziesii), two varieties, one being menziesii (dfm) and the other being glauca (dfg), were inoculated with the ectomycorrhizal fungus ... | 2008 | 18437431 |
| partitioning variation in douglas-fir xylem properties among multiple scales via a bayesian hierarchical model. | hierarchical biological scales permeate research in tree physiology and represent multiple sources of variation. we discuss the importance of matching the sampling and analysis scales to biological scales in the data. the advantages of statistical hierarchical modeling are demonstrated using the relationship between specific conductivity and tracheid diameter of secondary xylem as an example. the structure and results of three statistical models were compared within a bayesian context: a simple ... | 2008 | 18450566 |
| potential site productivity influences the rate of forest structural development. | development and maintenance of structurally complex forests in landscapes formerly managed for timber production is an increasingly common management objective. it has been postulated that the rate of forest structural development increases with site productivity. we tested this hypothesis for douglas-fir (pseudotsuga menziesii (mirb.) franco) forests using a network of permanent study plots established following complete timber harvest of the original old-growth forests. forest structural devel ... | 2008 | 18536251 |
| chemistry and long-term decomposition of roots of douglas-fir grown under elevated atmospheric carbon dioxide and warming conditions. | elevated atmospheric co(2) concentrations and warming may affect the quality of litters of forest plants and their subsequent decomposition in ecosystems, thereby potentially affecting the global carbon cycle. however, few data on root tissues are available to test this feedback to the atmosphere. in this study, we used fine (diameter < or = 2 mm) and small (2-10 mm) roots of douglas-fir (pseudotsuga menziesii (mirb.) franco) seedlings that were grown for 4 yr in a 2 x 2 factorial experiment: am ... | 2008 | 18574162 |
| nuclear bodies in douglas fir (pseudotsuga menziesii mirb.) microspores. | the identification of nucleolar proteins and immunocytochemical localization of small nuclear ribonucleoprotein (snrnp) elements revealed the presence of three types of nuclear bodies in douglas fir microspore nuclei. one type consists of structures resembling cajal bodies (cbs) and contains nucleolar proteins as well as snrnps and u2 snrna. the second type is bizonal bodies, which are nuclear bodies also linked with the splicing system. the bizonal body comprises two parts: the first contains s ... | 2008 | 18854917 |
| height-related trends in leaf xylem anatomy and shoot hydraulic characteristics in a tall conifer: safety versus efficiency in water transport. | hydraulic vulnerability of douglas-fir (pseudotsuga menziesii) branchlets decreases with height, allowing shoots at greater height to maintain hydraulic conductance (k shoot) at more negative leaf water potentials (psi l). to determine the basis for this trend shoot hydraulic and tracheid anatomical properties of foliage from the tops of douglas-fir trees were analysed along a height gradient from 5 to 55 m. values of psi l at which k shoot was substantially reduced, declined with height by 0.01 ... | 2008 | 18631290 |
| nitrogen leaching from douglas-fir forests after urea fertilization. | leaching of nitrogen (n) after forest fertilization has the potential to pollute ground and surface water. the purpose of this study was to quantify n leaching through the primary rooting zone of n-limited douglas-fir [pseudotsuga menziesii (mirb.) franco] forests the year after fertilization (224 kg n ha(-1) as urea) and to calculate changes in the n pools of the overstory trees, understory vegetation, and soil. at six sites on production forests in the hood canal watershed, washington, tension ... | 2008 | 18689739 |
| maximum height in a conifer is associated with conflicting requirements for xylem design. | despite renewed interest in the nature of limitations on maximum tree height, the mechanisms governing ultimate and species-specific height limits are not yet understood, but they likely involve water transport dynamics. tall trees experience increased risk of xylem embolism from air-seeding because tension in their water column increases with height because of path-length resistance and gravity. we used morphological measurements to estimate the hydraulic properties of the bordered pits between ... | 2008 | 18695232 |
| the histopathology of phaeocryptopus gaeumannii on douglas-fir needles. | germinating ascospores of phaeocryptopus gaeumannii produce suprastomatal appressoria from which penetration pegs enter needles. initial infection occurs between late may and early jul and coincides with budbreak and shoot elongation. colonization within needles is exclusively intercellular and increases continuously during jul-may. no intracellular hyphae or haustoria were observed, but hyphae closely appressed to mesophyll and palisade cell walls are abundant by 3-5 mo after initial infection. ... | 2008 | 18751550 |
| mycorrhizal networks and distance from mature trees alter patterns of competition and facilitation in dry douglas-fir forests. | the distribution of dry douglas-fir forests in western north america is expected to shift northward with climate change and disappear from the grassland interface in the southern interior of british columbia. this shift may be accentuated by clearcutting, a common harvesting practice that aims to reduce the competitive effects of residual mature trees on new regeneration, but in so doing, ignores their facilitative effects. in this study, we investigated the net effects of competition from and f ... | 2008 | 18781333 |
| toward using delta13c of ecosystem respiration to monitor canopy physiology in complex terrain. | in 2005 and 2006, air samples were collected at the base of a douglas-fir watershed to monitor seasonal changes in the delta13co2 of ecosystem respiration (delta13c(er)). the goals of this study were to determine whether variations in delta13c(er) correlated with environmental variables and could be used to predict expected variations in canopy-average stomatal conductance (gs). changes in delta13c(er) correlated weakly with changes in vapor pressure deficit (vpd) measured 0 and 3-7 days earlier ... | 2008 | 18839214 |
| stem-mediated hydraulic redistribution in large roots on opposing sides of a douglas-fir tree following localized irrigation. | *increasing evidence about hydraulic redistribution and its ecological consequences is emerging. hydraulic redistribution results from an interplay between competing plant and soil water potential gradients. in this work, stem-mediated hydraulic redistribution was studied in a 53-year-old douglas-fir tree during a period of drought. *sap flux density measurements using the heat field deformation method were performed at four locations: in two large opposing roots and on two sides of the tree ste ... | 2009 | 19754638 |
| enzymatic hydrolyzing performance of acremonium cellulolyticus and trichoderma reesei against three lignocellulosic materials. | bioethanol isolated from lignocellulosic biomass represents one of the most promising renewable and carbon neutral alternative liquid fuel sources. enzymatic saccharification using cellulase has proven to be a useful method in the production of bioethanol. the filamentous fungi acremonium cellulolyticus and trichoderma reesei are known to be potential cellulase producers. in this study, we aimed to reveal the advantages and disadvantages of the cellulase enzymes derived from these fungi. | 2009 | 19796378 |
| coupling tree-ring delta13c and delta15n to test the effect of fertilization on mature douglas-fir (pseudotsuga menziesii var. glauca) stands across the interior northwest, usa. | nitrogen (n) fertilization causes long-term increases in biomass production in many n-limited forests around the world, but the mechanistic basis underlying the increase is often unclear. one possibility, especially in summer-dry climates, is that n fertilization increases the efficiency with which a finite water supply is consumed to support photosynthesis. this increase is achieved by a reduction in the canopy-integrated concentration of internal co(2) and thus discrimination against (13)c. we ... | 2009 | 19855101 |
| effect of geographic isolation on genetic differentiation in dendroctonus pseudotsugae (coleoptera: curculionidae). | genetic structure of phytophagous insects has been widely studied, however, relative influence of the effect of geographic isolation, the host plant or both has been subject of considerable debate. several studies carried out on bark beetles in the genus dendroctonus evaluated these factors; nonetheless, recent evidence has shown that genetic structuring is a more complex process. our goal was to examine the effect of geographic isolation on genetic structure of the douglas-fir beetle dendrocton ... | 2009 | 19490169 |
| an integrated tool to assess the role of new planting in pm10 capture and the human health benefits: a case study in london. | the role of vegetation in mitigating the effects of pm(10) pollution has been highlighted as one potential benefit of urban greenspace. an integrated modelling approach is presented which utilises air dispersion (adms-urban) and particulate interception (ufore) to predict the pm(10) concentrations both before and after greenspace establishment, using a 10 x 10 km area of east london green grid (elgg) as a case study. the corresponding health benefits, in terms of premature mortality and respirat ... | 2009 | 19501436 |
| delayed conifer mortality after fuel reduction treatments: interactive effects of fuel, fire intensity, and bark beetles. | many low-elevation dry forests of the western united states contain more small trees and fewer large trees, more down woody debris, and less diverse and vigorous understory plant communities compared to conditions under historical fire regimes. these altered structural conditions may contribute to increased probability of unnaturally severe wildfires, susceptibility to uncharacteristic insect outbreaks, and drought-related mortality. broad-scale fuel reduction and restoration treatments are prop ... | 2009 | 19323193 |
| access to mycorrhizal networks and roots of trees: importance for seedling survival and resource transfer. | mycorrhizal networks (mns) are fungal hyphae that connect roots of at least two plants. it has been suggested that these networks are ecologically relevant because they may facilitate interplant resource transfer and improve regeneration dynamics. this study investigated the effects of mns on seedling survival, growth and physiological responses, interplant resource (carbon and nitrogen) transfer, and ectomycorrhizal (em) fungal colonization of seedlings by trees in dry interior douglas-fir (pse ... | 2009 | 19886489 |
| phytophthora rosacearum and p. sansomeana, new species segregated from the phytophthora megasperma "complex". | phytophthora megasperma sensu lato was a conglomeration of morphologically similar but phylogenetically unrelated species. in this paper we continue the segregation of species from the old p. megasperma complex, formally naming two previously recognized isolate groups. isolates recovered from rosaceous fruit trees (especially apple and cherry) are in its clade 6, related to but distinct from p. megasperma sensu strictu. they are named here phytophthora rosacearum. they have been referred to prev ... | 2009 | 19271675 |
| leaf hydraulic conductance, measured in situ, declines and recovers daily: leaf hydraulics, water potential and stomatal conductance in four temperate and three tropical tree species. | adequate leaf hydraulic conductance (kleaf) is critical for preventing transpiration-induced desiccation and subsequent stomatal closure that would restrict carbon gain. a few studies have reported midday depression of kleaf (or petiole conductivity) and its subsequent recovery in situ, but the extent to which this phenomenon is universal is not known. the objectives of this study were to measure kleaf, using a rehydration kinetics method, (1) in the laboratory (under controlled conditions) acro ... | 2009 | 19429900 |
| cost reduction and feedstock diversity for sulfuric acid-free ethanol cooking of lignocellulosic biomass as a pretreatment to enzymatic saccharification. | we have previously demonstrated that a sulfuric acid-free ethanol (etoh) cooking treatment enhances the enzymatic digestibility of eucalyptus wood and bagasse flour. in the present study, a reconfigured process that achieves similar performance was developed by identifying possible cost-competitive pretreatments that provide high cellulose-to-glucose conversion during subsequent enzymatic hydrolysis. the series of reconfigurations reduced etoh usage in the pretreatment by more than 80% in compar ... | 2009 | 19467864 |
| conifer embryogenic tissue initiation: improvements by supplementation of medium with d-xylose and d-chiro-inositol. | a major barrier to the commercialization of somatic embryogenesis technology in loblolly pine (lp, pinus taeda l.) is recalcitrance of some high-value crosses to initiate embryogenic tissue and to continue early-stage somatic embryo growth. developing initiation and multiplication media that resemble the seed environment may decrease this recalcitrance. sugar and sugar alcohol analyses were performed weekly throughout the sequence of seed development for female gametophyte and zygotic embryo tis ... | 2009 | 19203940 |
| native fauna on exotic trees: phylogenetic conservatism and geographic contingency in two lineages of phytophages on two lineages of trees. | the relative roles of evolutionary history and geographical and ecological contingency for community assembly remain unknown. plant species, for instance, share more phytophages with closer relatives (phylogenetic conservatism), but for exotic plants introduced to another continent, this may be overlaid by geographically contingent evolution or immigration from locally abundant plant species (mass effects). we assessed within local forests to what extent exotic trees (douglas-fir, red oak) recru ... | 2009 | 19296737 |
| enzymatic saccharification of woody biomass micro/nanofibrillated by continuous extrusion process i--effect of additives with cellulose affinity. | mechanical micro/nanofibrillation of douglas fir was performed by a continuous extrusion process in an attempt to develop a cost-effective pretreatment method for enzymatic saccharification. additives with cellulose affinity (ethylene glycol, glycerol, and dimethyl sulfoxide) were used to effectively fibrillate the wood cell wall into submicron- or nano-scale, thus opening up the cell wall structure for improving enzymatic accessibility, and lower the extrusion torque. morphological characteriza ... | 2009 | 18632266 |
| diversity and decomposing ability of saprophytic fungi from temperate forest litter. | this study was designed to examine saprophytic fungi diversity under different tree species situated in the same ecological context. further, the link between the diversity and decomposition rate of two broadleaved, two coniferous and two mixed broadleaved-coniferous litter types was targeted. litter material was decomposed in litter bags for 4 and 24 months to target both early and late stages of the decomposition. fungal diversity of l and f layers were also investigated as a parallel to the l ... | 2009 | 18982382 |
| incorporating diffuse photosynthetically active radiation in a single-leaf model of canopy photosynthesis for a 56-year-old douglas-fir forest. | a simple top-down model of canopy photosynthesis (p) was developed and tested in this study. the model (referred to as the q(e)-mm model) is p = alphaq (e) p (max)/(alphaq ( e ) + p (max)), alpha and p (max) are quantum-use efficiency and potential p, respectively. q (e) is given by q (d) (0) + kq (b) (0), where q (d) (0) and q (b) (0) are the diffuse and direct photosynthetically active radiation (par) incident on the canopy, respectively. q (e) can be considered to be the effective incident pa ... | 2009 | 19132410 |
| mycorrhizas on nursery and field seedlings of quercus garryana. | oak woodland regeneration and restoration requires that seedlings develop mycorrhizas, yet the need for this mutualistic association is often overlooked. in this study, we asked whether quercus garryana seedlings in nursery beds acquire mycorrhizas without artificial inoculation or access to a mycorrhizal network of other ectomycorrhizal hosts. we also assessed the relationship between mycorrhizal infection and seedling growth in a nursery. further, we compared the mycorrhizal assemblage of oak ... | 2009 | 19139931 |
| phylogeography of a specialist insect, adelges cooleyi: historical and contemporary processes shape the distribution of population genetic variation. | adelges cooleyi is a host-alternating, gall-making insect native to the rocky mountains and cascade mountains in western north america. the insect's primary hosts are picea (spruce) species, and its secondary host is pseudotsuga menziesii, douglas fir. to determine whether there are large-scale patterns of genetic variation in this specialist insect, we created molecular phylogenies of geographically separate samples of a. cooleyi using sequence data from two mitochondrial (mtdna) genes and ampl ... | 2009 | 19192184 |
| dynamic changes in concentrations of auxin, cytokinin, aba and selected metabolites in multiple genotypes of douglas-fir (pseudotsuga menziesii) during a growing season. | changes in concentrations of several endogenous phytohormones and metabolites were analyzed in the long shoots of nine genotypes of coastal douglas-fir (pseudotsuga menziesii (mirb.) franco var. menziesii) at five developmental stages: (1) closed buds, (2) flushing buds, (3) rapidly elongating shoots, (4) growing shoots and (5) near full-length shoots during one growing season. when averaged across genotypes, indole-3-acetic acid (iaa) concentration was high at stages 1 and 3. the only pattern t ... | 2009 | 19203943 |
| coordination of leaf structure and gas exchange along a height gradient in a tall conifer. | the gravitational component of water potential and frictional resistance during transpiration lead to substantial reductions in leaf water potential (psi(l)) near the tops of tall trees, which can influence both leaf growth and physiology. we examined the relationships between morphological features and gas exchange in foliage collected near the tops of douglas-fir (pseudotsuga menziesii (mirb.) franco) trees of different height classes ranging from 5 to 55 m. this sampling allowed us to investi ... | 2009 | 19203951 |
| temporal variation of nonstructural carbohydrates in montane conifers: similarities and differences among developmental stages, species and environmental conditions. | nonstructural carbohydrates (nscs) are commonly used to assess the balance of carbon sources and sinks in plants. a notable application of this approach has been tests of hypotheses on carbon limitations of trees at their upper altitudinal limits, near the alpine. how nscs vary in time is not well known in conifers during their critical seedling stage, despite the importance of knowing the temporal variations of nscs to use snapshot measurements of nscs to assess carbon balance. we measured nscs ... | 2009 | 19203971 |
| characterization of a strong cca-treated wood degrader, unknown crustoderma species. | in this study, basidiomycete isolates that possessed a strong ability to degrade chromated copper arsenate (cca)-treated wood were characterized. these fungal isolates, which were collected from cca-treated pine log wastes, showed no recognizable morphological properties on culture media. nucleotide sequence analysis of the large subunit rdna of the isolates revealed that they were one species. based on the high sequence similarity (>95%) and close phylogenetic relationship with several known sp ... | 2009 | 19205919 |
| ultrastructural studies of phellinus sulphurascens infection of douglas-fir roots and immunolocalization of host pathogenesis-related proteins. | interactions between roots of douglas-fir (df; pseudotsuga menziesii) seedlings and the laminated root rot fungus phellinus sulphurascens were investigated using scanning and transmission electron microscopy and immunogold labelling techniques. scanning electron micrographs revealed that p. sulphurascens hyphae colonize root surfaces and initiate the penetration of root epidermal tissues by developing appressoria within 2 d postinoculation (dpi). during early colonization, intra- and intercellul ... | 2009 | 19249366 |
| use of shaking treatments and preharvest sprays of pyrethroid insecticides to reduce risk of yellowjackets and other insects on christmas trees imported into hawaii. | insects are commonly found by hawaii's quarantine inspectors on christmas trees imported from the pacific northwest. to reduce the risk of importing yellowjacket (vespula spp.) queens and other insects, an inspection and tree shaking certification program was begun in 1990. from 1993 to 2006, the annual percentage of shipped containers rated by hawaii quarantine inspectors as moderately or highly infested with insects was significantly higher for manually shaken trees than for mechanically shake ... | 2009 | 19253620 |
| breeding without breeding. | an innovative approach to tree breeding called 'breeding without breeding' (bwb) is presented. the method, as applied on the material in hand, allows the capture of 75-85% of the genetic response to selection attained through conventional programmes without the need to do any controlled pollination and simplified or possibly no experimental field testing: both considered to be the most resource-demanding activities in breeding programmes. bwb combines the use of genotypic or phenotypic pre-selec ... | 2009 | 19393127 |
| forest fuel reduction alters fire severity and long-term carbon storage in three pacific northwest ecosystems. | two forest management objectives being debated in the context of federally managed landscapes in the u.s. pacific northwest involve a perceived trade-off between fire restoration and carbon sequestration. the former strategy would reduce fuel (and therefore c) that has accumulated through a century of fire suppression and exclusion which has led to extreme fire risk in some areas. the latter strategy would manage forests for enhanced c sequestration as a method of reducing atmospheric co2 and as ... | 2009 | 19425428 |
| association genetics of coastal douglas fir (pseudotsuga menziesii var. menziesii, pinaceae). i. cold-hardiness related traits. | adaptation to cold is one of the greatest challenges to forest trees. this process is highly synchronized with environmental cues relating to photoperiod and temperature. here, we use a candidate gene-based approach to search for genetic associations between 384 single-nucleotide polymorphism (snp) markers from 117 candidate genes and 21 cold-hardiness related traits. a general linear model approach, including population structure estimates as covariates, was implemented for each marker-trait pa ... | 2009 | 19487566 |
| stand-level gas-exchange responses to seasonal drought in very young versus old douglas-fir forests of the pacific northwest, usa. | this study examines how stand age affects ecosystem mass and energy exchange response to seasonal drought in three adjacent douglas-fir (pseudotsuga menziesii (mirb.) franco) forests. the sites include two early seral (es) stands (0-15 years old) and an old-growth (og) (approximately 450-500 years old) forest in the wind river experimental forest, washington, usa. we use eddy covariance flux measurements of carbon dioxide (f(nee)), latent energy (lambdae) and sensible heat (h) to derive evapotra ... | 2009 | 19502614 |
| effects of growth medium, nutrients, water, and aeration on mycorrhization and biomass allocation of greenhouse-grown interior douglas-fir seedlings. | commercial nursery practices usually fail to promote mycorrhization of interior douglas-fir [pseudotsuga menziesii (mirb.) franco var. glauca (beissn.) franco] seedlings in british columbia, which may account for their poor performance following planting in the field. we tested the effects of four nursery cultivation factors (nitrogen fertilization, phosphorus fertilization, watering, and soil aeration) and field soil addition on mycorrhization, survival, growth, and biomass allocation of interi ... | 2009 | 19572155 |
| multilocus patterns of nucleotide diversity and divergence reveal positive selection at candidate genes related to cold hardiness in coastal douglas fir (pseudotsuga menziesii var. menziesii). | forest trees exhibit remarkable adaptations to their environments. the genetic basis for phenotypic adaptation to climatic gradients has been established through a long history of common garden, provenance, and genecological studies. the identities of genes underlying these traits, however, have remained elusive and thus so have the patterns of adaptive molecular diversity in forest tree genomes. here, we report an analysis of diversity and divergence for a set of 121 cold-hardiness candidate ge ... | 2009 | 19596906 |
| [forensic examinations of clothing and other materials found in the coffin by the body of general władysław sikorski]. | the report presents the results of identification of garments and other textile products, as well as various materials, e.g. fragments of metals, wood slivers and chemical substances found in the coffin by the body of general władysław sikorski. the articles of clothing revealed no damages that could have resulted from a thermal factor, such as fire, high temperature or explosion. mechanical damages of fabric and knitted fabric resulted from annealing processes and biodegradation of the products ... | 2009 | 19711819 |
| [species identification of the fragment of wood found in the left eye socket bone during exhumation of general władysław sikorski's corpse]. | during the exhumation of general władysław sikorski's corpse, a fragment of wood was found embedded in the left eye socket bone. the wood fragment was referred by the institute of forensic research to the laboratory of department of forest and wood utilization, university of agriculture in krakow, where investigations were performed, aiming at determining the species of the wood. the fragment was cut into 20 microm thick microtome scraps of three anatomy sections: transverse, tangential and radi ... | 2009 | 19711820 |
| architecture of the wood-wide web: rhizopogon spp. genets link multiple douglas-fir cohorts. | *the role of mycorrhizal networks in forest dynamics is poorly understood because of the elusiveness of their spatial structure. we mapped the belowground distribution of the fungi rhizopogon vesiculosus and rhizopogon vinicolor and interior douglas-fir trees (pseudotsuga menziesii var. glauca) to determine the architecture of a mycorrhizal network in a multi-aged old-growth forest. *rhizopogon spp. mycorrhizas were collected within a 30 x 30 m plot. trees and fungal genets were identified using ... | 2010 | 19878460 |
| fine root decomposition rates do not mirror those of leaf litter among temperate tree species. | elucidating the function of and patterns among plant traits above ground has been a major research focus, while the patterns and functioning of belowground traits remain less well understood. even less well known is whether species differences in leaf traits and their associated biogeochemical effects are mirrored by differences in root traits and their effects. we studied fine root decomposition and n dynamics in a common garden study of 11 temperate european and north american tree species (ab ... | 2010 | 19882174 |
| density-independent high moisture content measurement using phase shifts at two microwave frequencies. | density-independent high moisture content measurement is required in actual production line. in this paper, the experimental results for high moisture content measurement using microwave free-space technique are presented. the method is based on a ratio of phase shifts at two microwave frequencies after propagating through a sample. the experiments were performed with three kinds of sawdust named momizai, cedar and douglas fir. in the high moisture content above 130%, the root mean square error ... | 2010 | 21721335 |
| the isolation, characterization and effect of lignin isolated from steam pretreated douglas-fir on the enzymatic hydrolysis of cellulose. | douglas-fir was so(2)-steam pretreated at different severities (190, 200, and 210°c) to assess the possible negative effect of the residual and isolated lignins on the enzymatic hydrolysis of the steam pretreated substrates. when various isolated lignins were added to the avicel hydrolysis reactions, the decrease in glucose yields ranged from 15.2% to 29.0% after 72 h. it was apparent that the better hydrolysis yields obtained at higher pretreatment severities were more a result of the greater a ... | 2010 | 21256740 |
| kalapuya brunnea gen. & sp. nov. and its relationship to the other sequestrate genera in morchellaceae. | kalapuya is described as a new, monotypic truffle genus in the morchellaceae known only from the pacific northwestern united states. its relationship to other hypogeous genera within morchellaceae is explored by phylogenetic analysis of the ribosomal lsu and ef1alpha protein coding region. the type species, k. brunnea, occurs in douglas-fir forests up to about 50 y old on the west slope of the cascade range in oregon and in the coastal ranges of oregon and northern california. it has a roughened ... | 2010 | 20943505 |