Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| plant moisture stress: evaluation by pressure bomb. | the recently developed technique for determining the water stress of a plant by measuring the pressure necessary to force water back to the cut surface of a severed twig is adaptable to both field and laboratory experiments. we have designed and operated an efficient portable system weighing less than 18 kilograms. sampling variation within and among douglas fir trees varies from less than +/- i atmosphere under low stress conditions to +/- 10 atmospheres under high stress conditions. in the mea ... | 1967 | 17847540 |
| 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 |
| 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 |
| 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 |
| constituents of extractive from douglas-fir lignin residue. | 1948 | 18102931 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| implications of differing input data sources and approaches upon forest carbon stock estimation. | site index is an important forest inventory attribute that relates productivity and growth expectation of forests over time. in forest inventory programs, site index is used in conjunction with other forest inventory attributes (i.e., height, age) for the estimation of stand volume. in turn, stand volumes are used to estimate biomass (and biomass components) and enable conversion to carbon. in this research, we explore the implications and consequences of different estimates of site index on car ... | 2010 | 19517261 |
| 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 |
| 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 |
| 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 |
| 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 |
| female reproductive success variation in a pseudotsuga menziesii seed orchard as revealed by pedigree reconstruction from a bulk seed collection. | the impact of female reproductive success on the mating system, gene flow, and genetic diversity of the filial generation was studied using a random sample of 801 bulk seed from a 49-clone pseudotsuga menziesii seed orchard. we used microsatellite dna fingerprinting and pedigree reconstruction to assign each seed's maternal and paternal parents and directly estimated clonal reproductive success, selfing rate, and the proportion of seed sired by outside pollen sources. unlike most family array ma ... | 2010 | 20080805 |
| evaluation of resistance to rhabdocline needlecast in douglas fir variety shuswap, with quantitative polymerase chain reaction. | a quantitative polymerase chain reaction assay was developed that could detect dna of rhabdocline pseudotsugae and r. oblonga among dna of douglas fir needles to a limit as low as three copies of target dna. differential infection rates of two varieties (seed sources) of douglas fir interplanted in a field were studied in relation to staggered bud breaks. infection of douglas fir var. san isabel corresponded to ascospore release times for rhabdocline spp., whereas infection of var. shuswap lake ... | 2010 | 20205537 |
| 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 |
| 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 |
| 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 |
| 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 |
| enzymatic saccharification of woody biomass micro/nanofibrillated by continuous extrusion process ii: effect of hot-compressed water treatment. | an extrusion process involving a twin-screw extruder was used for the micro/nanofibrillation of douglas fir and eucalyptus treated with hot-compressed water (hcw). partial removal of hemicellulose and lignin by hcw treatment effectively improved the fibrillation by extrusion. only hcw treatment produced glucose less than 5 weight percent (wt.%) in douglas fir in a temperature range of 140-180 degrees c by enzymatic hydrolysis. glucose production yields of 18 and 26 wt.% were obtained by hcw trea ... | 2010 | 20709531 |
| 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 |
| 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 |
| southward pleistocene migration of douglas-fir into mexico: phylogeography, ecological niche modeling, and conservation of 'rear edge' populations. | • poleward pleistocene plant migration has been an important process structuring modern temperate and boreal plant communities, but the contribution of equatorward migration remains poorly understood. paleobotanical evidence suggests miocene or pleistocene origin for temperate 'sky island' plant taxa in mexico. these 'rear edge' populations situated in a biodiversity hotspot may be an important reserve of genetic diversity in changing climates. • we used mtdna sequences, cpdna sequences and chlo ... | 2010 | 21118265 |
| habitat and host associations of craterellus tubaeformis in northwestern oregon. | knowledge of the habitat and host associations of craterellus tubaeformis (winter chanterelle) is the key to understanding the ecological characteristics needed for its conservation. in this study, a survey of forest types in northwestern oregon for mycorrhizal associates is performed and the hypotheses that stand age and the volume of well-decayed, coarse, woody debris (cwd) are significant to the standing crop biomass and the probability of c. tubaeformis occurrence are tested. host associatio ... | 2004 | 21148873 |
| 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 |