| bleach boosting and direct brightening by multiple xylanase treatments during peroxide bleaching of kraft pulps. | the effects of multiple xylanase treatments were assessed during the peroxide bleaching of three pulps: douglas-fir (kraft); western hemlock (oxygen delignified 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 before and one after the peroxide stage(s). both bleach boosting and direct brighteni ... | 1997 | 18634097 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| a flavonone from douglas-fir heartwood. | | 1948 | 18882535 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| gene cloning and tissue expression analysis of a pr-5 thaumatin-like protein in phellinus weirii-infected douglas-fir. | abstract in western north america, douglas-fir (pseudotsuga menziesii) is the most economically important conifer species susceptible to laminated root rot caused by phellinus weirii. while attempting to internally sequence an endochitinase found to be up-regulated in p. weirii-infected douglas-fir roots, we obtained overlapping peptide fragments showing 28% similarity with a pr-5 thaumatin-like protein (tlp) designated pmtlp (pm for pseudotsuga menziesi). a rabbit polyclonal antibody was reared ... | 2004 | 18944459 |
| 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 |
| 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 |
| 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 |
| sound production in scolytidae:chemostimulus of sonic signal by the douglas-fir beetle. | stridulation by male dendroctonus pseudotsugae was recorded in response to the natural female attractant (frass) or to three synthetic components of the attractant (frontalin, 3-methyl-2-cyclohexen-1-one, and trans-verbenol). this stridulation was acoustically distinct from stress sound and correlated with known attraction behavior. the response of female d. pseudotsugae to male stridulation-negation her attraction-was induced by playback of recorded attractant stridulation but not by that of st ... | 1972 | 17813834 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| histopathology and host range studies of the redwood nematode rhizonema sequoiae. | second-stage larvae of rehizonma sequoiae cid del prado vera et al. tunnel through the cortex of the redwood sequoia sempervirens (d. don) endl. root to the vascular tissue where each developing female induces a single ovoid or occasionally spherical giant cell with a single ovoid to spherical nucleus containing one to four enlarged nucleoli. nematode tunnels are filled with a gel material and often contain second-stage larvae and males. there is tissue necrosis around females, and cortical tiss ... | 1984 | 19295877 |
| 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 |
| nacobbodera chitwoodi, n. gen., n. sp., (nacobbidae:nematoda) on douglas fir in oregon. | nacobbodera chitwoodi, n. gen., n. sp., representing nacobboderinae n. subfam, in the nacobbidae, is described and illustrated from roots of douglas fir, pseudotsuga menziesii near florence oregon. this new species, having characters common to nacobbidae, heteroderidae, and meloidogynidae, appears to represent a connecting link between these three families of the heteroderoidea. especially, a distinct tail on swollen adult females, vermiform shape of juvenile females, and the shape and sclerotiz ... | 1974 | 19319361 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| height-related trends in stomatal sensitivity to leaf-to-air vapour pressure deficit in a tall conifer. | stomatal responses to leaf-to-air vapour pressure deficit (lvpd), leaf water potential components, and cuticular properties were characterized for douglas-fir (pseudotsuga menziesii) foliage collected from tree tops along a height gradient from 5 m to 58 m in order to explore height-related trends in stomatal sensitivity to lvpd and to investigate the role of bulk leaf turgor and leaf cuticle thickness in determining stomatal behaviour. there were three distinct phases in the response of stomata ... | 2010 | 19933710 |
| defining how aging pseudotsuga and abies compensate for multiple stresses through multi-criteria assessment of a functional-structural model. | many hypotheses have been advanced about factors that control tree longevity. we use a simulation model with multi-criteria optimization and pareto optimality to determine branch morphologies in the pinaceae that minimize the effect of growth limitations due to water stress while simultaneously maximizing carbohydrate gain. two distinct branch morphologies in the pareto optimal space resemble pseudotsuga menziesii (mirb.) franco and abies grandis (dougl. ex d. don) lindl., respectively. these mo ... | 2010 | 19945994 |
| ph affects ammonium, nitrate and proton fluxes in the apical region of conifer and soybean roots. | the effect of ph on nitrate and ammonium uptake in the high-affinity transport system and low-affinity transport system ranges was compared in two conifers and one crop species. many conifers grow on acidic soils, thus their preference for ammonium vs nitrate uptake can differ from that of crop plants, and the effect of ph on nitrogen (n) uptake may differ. proton, ammonium and nitrate net fluxes were measured at seedling root tips and 5, 10, 20 and 30 mm from the tips using a non-invasive micro ... | 2010 | 19947965 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| fire and mice: seed predation moderates fire's influence on conifer recruitment. | in fire-adapted ecosystems, fire is presumed to be the dominant ecological force, and little is known about how consumer interactions influence forest regeneration. here, we investigated seed predation by deer mice (peromyscus maniculatus) and its effects on recruitment of ponderosa pine (pinus ponderosa) and douglas-fir (pseudotsuga menziesii) seedlings in unburned and recently burned fire-adapted montane forests in west-central montana, usa. deer mice were almost twice as abundant in burned th ... | 2010 | 20462126 |
| optimized delignification of wood-derived lignocellulosics for improved enzymatic hydrolysis. | one of the major bottlenecks in the bioconversion of lignocelluosic feedstocks to liquid ethanol is the recalcitrance of residue following pretreatment, specifically softwood derived residues. peroxide delignification has previously been shown to effectively aid in the removal of condensed lignaceous moieties from substrates following pretreatment, and thereby improve the hydrolyzability of the polymeric carbohydrates to their monomeric constituents. despite the effectiveness of peroxide, drawba ... | 2010 | 20506220 |
| 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 |
| 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 |
| quantification of nitrogen reductase and nitrite reductase genes in soil of thinned and clear-cut douglas-fir stands by using real-time pcr. | the abundance of nifh, nirs, and nirk gene fragments involved in nitrogen (n) fixation and denitrification in thinned second-growth douglas-fir (pseudotsuga menziesii subsp. menziesii [mirb.] franco) forest soil was investigated by using quantitative real-time pcr. prokaryotic n cycling is an important aspect of n availability in forest soil. the abundance of universal nifh, azotobacter sp.-specific nifh (nifh-g1), nirs, and nirk gene fragments in unthinned control and 30, 90, and 100% thinning ... | 2010 | 20802070 |
| impact of swiss needle-cast on growth of douglas-fir. | phaeocryptopus gaeumannii, the cause of swiss needle-cast, is widely distributed in plantations of douglas-fir in many parts of the world. nevertheless, information remains limited on its precise effect on stand growth, particularly in relation to regional climate, and on its consequent economic cost. in new zealand, the spread of p. gaeumannii over a period of ≈30 years following its discovery in 1959 was closely monitored, and the timing of its arrival in different forests is known. this infor ... | 2011 | 20923368 |
| 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 |
| 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 |
| fusarium commune is a new species identified by morphological and molecular phylogenetic data. | fusarium commune sp. nov. was isolated from soil and pisum sativum in denmark and several widespread locations within the northern hemisphere from diverse substrates including white pine, douglas fir, carnation, corn, carrot, barley and soil. fusarium commune is characterized by and distinguished from its putative sister taxon, the f. oxysporum complex, in having long, slender monophialides and polyphialides when cultured in the dark. based on the combined dna sequence data from translation elon ... | 2003 | 21148972 |
| a comparative toxicity assessment of materials used in aquatic construction. | comparative toxicity testing was performed on selected materials that may be used in aquatic construction projects. the tests were conducted on the following materials: (1) untreated wood species (hemlock [tsuga ssp], western red cedar (thuja plicata), red oak [quercus rubra], douglas fir [pseudotsuga menziesii], red pine [pinus resinosa], and tamarack [larix ssp]); (2) plastic wood; (3) ecothermo wood hemlock stakes treated with preservatives (e.g., chromated copper arsenate [cca], creosote, al ... | 2011 | 21222116 |
| predicting swiss needle cast disease distribution and severity in young douglas-fir plantations in coastal oregon. | abstract swiss needle cast (snc), caused by the fungus phaeocryptopus gaeumannii, is producing extensive defoliation and growth reduction in douglas-fir forest plantations along the pacific northwest coast. an snc disease prediction model for the coastal area of oregon was built by establishing the relationship between the distribution of disease and the environment. a ground-based disease survey (220 plots) was used to study this relationship. two types of regression approaches, multiple linear ... | 2003 | 18943159 |
| ectomycorrhizal hyphae structure components of the soil bacterial community for decreased phosphatase production. | ectomycorrhizal fungi (emf) provide nutrients to their hosts by means of hyphae that extend beyond nutrient-depleted rhizosphere soil. soil bacteria may compete with emf for nutrients or may act synergistically to enhance nutrient supply to hosts. to assess the interactions between hyphae and bacteria, two types of small, sand-filled mesh bags were incubated in a pseudotsuga menziesii/betula papyrifera forest. the bags allowed ingrowth by emf (35-µm mesh) or excluded hyphae (0.5-µm mesh), while ... | 2011 | 21265870 |
| climate-related trends in sapwood biophysical properties in two conifers: avoidance of hydraulic dysfunction through coordinated adjustments in xylem efficiency, safety and capacitance. | in the pacific north-west, the cascade mountain range blocks much of the precipitation and maritime influence of the pacific ocean, resulting in distinct climates east and west of the mountains. the current study aimed to investigate relationships between water storage and transport properties in populations of douglas-fir (pseudotsuga menziesii) and ponderosa pine (pinus ponderosa) adapted to both climates. sapwood thickness, capacitance, vulnerability to embolism, and axial and radial conducti ... | 2011 | 21309793 |
| cellulose accessibility limits the effectiveness of minimum cellulase loading on the efficient hydrolysis of pretreated lignocellulosic substrates. | a range of lignocellulosic feedstocks (including agricultural, softwood and hardwood substrates) were pretreated with either sulfur dioxide-catalyzed steam or an ethanol organosolv procedure to try to establish a reliable assessment of the factors governing the minimum protein loading that could be used to achieve efficient hydrolysis. a statistical design approach was first used to define what might constitute the minimum protein loading (cellulases and ß-glucosidase) that could be used to achi ... | 2011 | 21310050 |
| a climate-based model for predicting geographic variation in swiss needle cast severity in the oregon coast range. | abstract since the early 1990s, swiss needle cast disease caused by phaeocryptopus gaeumannii has been increasing in douglas-fir plantations in the oregon coast range. considerable variation in disease severity across the affected area often has been noted. we investigated the influence of site microclimate on fungal colonization as a basis for this variation with a combination of seedling inoculation and field studies. development of p. gaeumannii ascocarps on inoculated seedlings subjected to ... | 2005 | 18943355 |
| simultaneous one-tube quantification of host and pathogen dna with real-time polymerase chain reaction. | abstract phaeocryptopus gaeumannii is a widespread foliar parasite of douglas-fir. although normally innocuous, the fungus also causes the defoliating disease swiss needle cast in heavily infected needles. the extent of p. gaeumannii colonization in douglas-fir foliage was estimated with real-time quantitative polymerase chain reaction (pcr) using taqman chemistry. in order to derive a normalized expression of colonization, both pathogen and host dna were simultaneously amplified but individuall ... | 2002 | 18944147 |
| assessment of uncertainty in functional-structural plant models. | background and aims constructing functional-structural plant models (fspms) is a valuable method for examining how physiology and morphology interact in determining plant processes. however, such models always have uncertainty concerned with whether model components have been selected and represented effectively, with the number of model outputs simulated and with the quality of data used in assessment. we provide a procedure for defining uncertainty of an fspm and how this uncertainty can be re ... | 2011 | 21593061 |
| comparison of biochemical, molecular, and visual methods to quantify phaeocryptopus gaeumannii in douglas-fir foliage. | abstract a recent epidemic of swiss needle cast along the oregon coast has prompted efforts to quantify foliar infection and colonization of the causal agent phaeocryptopus gaeumannii. in this paper, we compare four methods to quantify colonization of douglas-fir foliage by p. gaeumannii: fruiting body abundance, ergosterol content, dot blot analysis, and taqman based real-time quantitative polymerase chain reaction (pcr). results from the four techniques were all significantly correlated. fruit ... | 2003 | 18944165 |
| the ecology of tick-transmitted infections in the redwood chipmunk (tamias ochrogenys). | the redwood chipmunk contributes to the maintenance of tick-borne diseases in northern california. the range of redwood chipmunks overlaps that of western black-legged ticks and tick-borne disease, including granulocytic anaplasmosis and lyme borreliosis. chipmunks have high anaplasma phagocytophilum pcr- and seroprevalence, are infested with a diversity of ixodes spp. ticks, and are reservoir competent for borrelia burgdorferi. we hypothesized that chipmunks could maintain tick-borne disease on ... | 2011 | 21643481 |
| female parthenogenetic apomixis and androsporogenesis in douglas-fir embryonal initials in an artificial sporangium. | control of female parthenogenetic apomixis and androsporogenesis of douglas-fir embryonal initials was studied using an experimental culture system in which changes in growth condition can mediate changes in cell identity and outcomes. this culture system constitutes an artificial sporangium in which myriad culture conditions can be simulated and should be applicable for research on a variety of gymnosperms. in this study, embryonal initials from developing seeds from two douglas-fir trees were ... | 2011 | 21644002 |
| identification, characterization, and expression analyses of class ii and iv chitinase genes from douglas-fir seedlings infected by phellinus sulphurascens. | laminated root rot (lrr) disease, caused by the fungus phellinus sulphurascens, is a major threat to coastal douglas-fir (df) (pseudotsuga menziesii) forests in western north america. understanding host-pathogen interactions of this pathosystem is essential to manage this important conifer root disease. our research objectives were to identify df pathogenesis-related (pr) genes and analyze their expression patterns over the course of infection. we constructed a cdna library of phellinus sulphura ... | 2010 | 20205539 |
| genotypic variation among douglas-fir tussock moth nucleopolyhedrovirus (opnpv) isolates in the western united states. | periodic outbreaks of the douglas-fir tussock moth (orgyia pseudotsugata) in forests of western north america generally end with a sudden collapse due primarily to an epizootic caused by a nucleopolyhedrovirus (npv) that occurs naturally within o. pseudotsugata populations. we genotypically characterized npv populations from washington state, oregon, idaho, new mexico and california for the first time. of 159 infected tussock moth samples, restriction fragment length polymorphism (rflp) analysis ... | 2011 | 21684287 |
| food-related odor probes of brain reward circuits during hunger: a pilot fmri study. | food aromas can be powerful appetitive cues in the natural environment. although several studies have examined the cerebral responses to food images, none have used naturalistic food aromas to study obesity. ten individuals (five normal-weight and five obese) were recruited to undergo 24 h of food deprivation. subjects were then imaged on a 3t siemens trio-tim scanner (siemens, erlangen, germany) while smelling four food-related odors (fro; two sweet odors and two fat-related) and four "nonappet ... | 2010 | 20339365 |
| phylogeography of douglas-fir based on mitochondrial and chloroplast dna sequences: testing hypotheses from the fossil record. | the integration of fossil and molecular data can provide a synthetic understanding of the ecological and evolutionary history of an organism. we analysed range-wide maternally inherited mitochondrial dna and paternally inherited chloroplast dna sequence data with coalescent simulations and traditional population genetic methods to test hypotheses of population divergence generated from the fossil record of douglas-fir (pseudotsuga menziesii), an ecologically and economically important western no ... | 2010 | 20374486 |
| soil moisture effects on the carbon isotope composition of soil respiration. | the carbon isotopic composition (delta(13)c) of recently assimilated plant carbon is known to depend on water-stress, caused either by low soil moisture or by low atmospheric humidity. air humidity has also been shown to correlate with the delta(13)c of soil respiration, which suggests indirectly that recently fixed photosynthates comprise a substantial component of substrates consumed by soil respiration. however, there are other reasons why the delta(13)co(2) of soil efflux may change with moi ... | 2010 | 20391598 |
| soil microbial communities associated with douglas-fir and red alder stands at high- and low-productivity forest sites in oregon, usa. | communities of archaea, bacteria, and fungi were examined in forest soils located in the oregon coast range and the inland cascade mountains. soils from replicated plots of douglas-fir (pseudotsuga menziesii) and red alder (alnus rubra) were characterized using fungal its (internal transcribed spacer region), eubacterial 16s rrna, and archaeal 16s rrna primers. population size was measured with quantitative (q)-pcr and composition was examined using length heterogeneity (lh)-pcr for fungal compo ... | 2010 | 20449582 |
| water stress, shoot growth and storage of non-structural carbohydrates along a tree height gradient in a tall conifer. | we analysed concentrations of starch, sucrose, glucose and fructose in upper branch wood, foliage and trunk sapwood of douglas-fir trees in height classes ranging from ôê+2 to ôê+57ôçâm. mean concentrations of non-structural carbohydrates (nsc) for all tissues were highest in the tallest height class and lowest in the lowest height class, and height-related trends in nsc were most pronounced in branches. throughout a 17-month sampling period, mean values of branch nsc from the 57ôçâm trees range ... | 2011 | 21722142 |
| evaluation of hemicellulose removal by xylanase and delignification on shf and ssf for bioethanol production with steam-pretreated substrates. | steam-pretreated sweet sorghum bagasse (ssb) and douglas-fir (df) were employed for shf and ssf to evaluate the effects of xylanase supplementation and delignification on ethanol production. results indicated final ethanol concentration in shf could reach 28.4g/l (ssb) and 20.4g/l (df) by xylanase supplementation with the increase of 46% and 61% in comparison with controls. the delignification could significantly enhance final ethanol concentration to 31.2g/l (ssb) and 30.2g/l (df) with the incr ... | 2011 | 21816609 |
| role of relative humidity in colony founding and queen survivorship in two carpenter ant species. | conditions necessary for optimal colony foundation in two carpenter ant species, camponotus modoc wheeler and camponotus vicinus mayr, were studied. camponotus modoc and c. vicinus queens were placed in douglas-fir, pseudotsuga menziesii (mirb. franco) and styrofoam blocks conditioned in sealed chambers at 70, 80, or 100% rh. nanitic workers produced after 12 wk were used to assess the effects of substrate and moisture content on colony initiation. queens of c. vicinus in douglas-fir and styrofo ... | 2011 | 21735888 |
| sea sand disruption method (ssdm) as a valuable tool for isolating essential oil components from conifers. | essential oils are one of nature's most precious gifts with surprisingly potent and outstanding properties. coniferous oils, for instance, are nowadays being used extensively to treat or prevent many types of infections, modify immune responses, soothe inflammations, stabilize moods, and to help ease all forms of non-acute pain. given the broad spectrum of usage of coniferous essential oils, a fast, safe, simple, and efficient sample-preparation method is needed in the estimation procedure of es ... | 2011 | 22083917 |
| can the same steam pretreatment conditions be used for most softwoods to achieve good, enzymatic hydrolysis and sugar yields? | wood chips from six different douglas-fir trees and a representative lodgepole pine were steam pretreated at a single pretreatment condition (200 degrees c 4% so(2) 5min) which had previously been shown to be effective for spruce and lodgepole pine chips. all of the softwood samples responded in a similar fashion with more than 60% of the cellulose hydrolysed after 72h, at an enzyme loading of 20fpu/g cellulose. however, when the enzyme loading was reduced to 5fpu, less than 27% of the cellulose ... | 2010 | 20570139 |
| defining historical baselines for conservation: ecological changes since european settlement on vancouver island, canada. | conservation and restoration goals are often defined by historical baseline conditions that occurred prior to a particular period of human disturbance, such as european settlement in north america. nevertheless, if ecosystems were heavily influenced by native peoples prior to european settlement, conservation efforts may require active management rather than simple removal of or reductions in recent forms of disturbance. we used pre-european settlement land survey records (1859-1874) and contemp ... | 2010 | 20586787 |
| grafting of aminated oligogalacturonans onto douglas fir barks. a new route for the enhancement of their lead (ii) binding capacities. | chemical modification of douglas fir bark and its subsequent utilization in adsorption of pbii from aqueous solutions was investigated. a new approach to enhance the natural properties of bark by covalent grafting of oligogalacturonans was developed. the polysaccharidic moiety of barks was functionalized by periodate oxidation and derivatized after reductive amination in presence of aminated oligogalacturonic acid. pbii adsorption isotherms of derivatized barks were then determined and compared ... | 2010 | 20615613 |