Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| sequence and expression of embryogenesis-specific cdnas encoding 2s seed storage proteins in pseudotsuga menziesii [mirb.] franco. | differential screening of a cdna library constructed from polyadenylated rna from developing douglas-fir (pseudotsuga menziesii [mirb.] franco) seeds resulted in the isolation of four full-length cdna clones (pm2s1, pm2s2, pm2s3 and pm2s4) encoding isoforms of 2s seed storage proteins. the deduced amino acid sequences had low similarity to the angiosperm 2s storage proteins such as 2s albumin, napin and alpha-amylase/trypsin inhibitor yet contained all conserved cysteines in an arrangement sugge ... | 1998 | 9715536 |
| yeast adaptation on softwood prehydrolysate. | several strains and genera of yeast, including saccharomyces cerevisiae d5a, pachysolen tannophilus, s. cerevisiae k-1, brettanomyces custersii, candida shehatae, and candida acidothermophilum, are screened for growth on dilute acid-pretreated softwood prehydrolysate. selected softwood species found in forest underbrush of the western united states, which contain predominantly hexosan hemicellulose, were studied. this phase of the work emphasized debarked douglas fir. the two best initial isolat ... | 1998 | 9627379 |
| conversion of total leaf area to projected leaf area in lodgepole pine and douglas-fir. | three definitions of leaf area index (lai) in the literature have no predictable relationship with each other. factors were derived for converting total lai to projected lai of horizontal leaves and to projected lai for inclined leaves of lodgepole pine (pinus contorta dougl. var. latifolia engelm.) and coastal douglas-fir (pseudotsuga menziesii (mirb.) franco) to allow comparison of results from different studies. an algorithm was derived to allow determination of these factors based on twig an ... | 1998 | 12651388 |
| a model of dry matter partitioning in trees. | in mechanistic growth models, the description of assimilate allocation or dry matter partitioning plays a key role. although theoretical concepts of allocation exist, they include many parameters that cannot be quantified. therefore, many growth models use descriptive keys that represent the proportions of dry matter or carbohydrates assigned to each plant component. i have developed a model to describe the dynamic partitioning of dry matter in individual trees, and used it to investigate the ef ... | 1998 | 12651393 |
| influence of ectomycorrhizal fungal inoculation on growth and root iaa concentrations of transplanted conifers. | we determined whether in vitro plant growth regulator production by mycorrhizal fungi is correlated with conifer seedling growth and root iaa concentrations. container-grown seedlings of interior douglas-fir (pseudotsuga menziesii (mirb.) franco), lodgepole pine (pinus contorta dougl.) and ponderosa pine (pinus ponderosa dougl.) were inoculated at seeding with ectomycorrhizal fungi having a high, moderate or low capacity to produce either iaa or ethylene in vitro. inoculated seedlings were grown ... | 1998 | 12651408 |
| hydraulic properties of douglas-fir (pseudotsuga menziesii) branches and branch halves with reference to compression wood. | douglas-fir (pseudotsuga menziesii var. menziesii (mirb.) franco) branch segments were used to test the hypothesis that compression wood reduces xylem transport efficiency. whole 3-year-old segments were first measured for specific conductivity (k(s), m(2) s(-1) mpa(-1)), then split lengthwise into upper and lower halves, the latter containing all or most of the compression wood in the segment. halves were then remeasured for k(s) using a new technique that prevents leakage of permeating fluid d ... | 1998 | 12651412 |
| electroantennogram responses of douglas-fir seed chalcids to plant volatiles. | douglas fir seed chalcids females oviposit specifically into douglas cones which they locate using olfactory and visual cues. we have tested whether this specialization was correlated with a specialized sensitivity towards cone volatiles. field collected adults were presented a series of pure volatile chemicals. electroantennogram responses (eag) were recorded to generally occurring terpenoids and straight chain alcohols and aldehydes found in flowers and plant leaves. monoterpenes identified in ... | 1998 | 12770168 |
| prfll--a pinus radiata homologue of floricaula and leafy is expressed in buds containing vegetative shoot and undifferentiated male cone primordia. | in angiosperms, the formation of the flower meristem is controlled by partially redundant flower meristem identity genes of which floricaula (flo)/leafy (lfy) plays a central role. it is not known whether formation of reproductive organs of pre-angiosperm species is similarly regulated. recently, a flo/lfy-like cdna, needly (nly), has been cloned in a conifer species pinus radiata (d. don). here we report cloning of a different pinus radiata flo/lfy-like cdna, prfll. prfll had two large regions ... | 1998 | 9821691 |
| physical mapping and characterization of 5s rrna genes in douglas-fir. | douglas-fir [pseudotsuga menziesii (mirb.) franco] is one of the world's most valuable timber species and is widely used in reforestation. therefore there is considerable interest in understanding its genetic structure. in conifers approximately 75% of the genome is composed of repetitive dna. thus for conifers characterization of repetitive dna is a significant part of genome analysis. we have characterized the organization of 5s rrna genes in douglas-fir at both the molecular and chromosome le ... | 1998 | 9864860 |
| analysis of nifh gene pool complexity in soil and litter at a douglas fir forest site in the oregon cascade mountain range. | nitrogen-fixing microbial populations in a douglas fir forest on the western slope of the oregon cascade mountain range were analyzed. the complexity of the nifh gene pool (nifh is the marker gene which encodes nitrogenase reductase) was assessed by performing nested pcr with bulk dna extracted from plant litter and soil. the restriction fragment length polymorphisms (rflps) of pcr products obtained from litter were reproducibly different than the rflps of pcr products obtained from the underlyi ... | 1999 | 9925556 |
| structure and dynamics of experimentally introduced and naturally occurring laccaria sp. discrete genotypes in a douglas fir plantation | ectomycorrhizal fungi have been introduced in forest nurseries to improve seedling growth. outplanting of inoculated seedlings to forest plantations raises the questions about inoculant persistence and its effects on indigenous fungal populations. we previously showed (m.-a. selosse et al. mol. ecol. 7:561-573, 1998) that the american strain laccaria bicolor s238n persisted 10 years after outplanting in a french douglas fir plantation, without introgression or selfing and without fruiting on uni ... | 1999 | 10223992 |
| fermentability of the hemicellulose-derived sugars from steam-exploded softwood (douglas fir) | steam explosion ofdouglas fir wood chips under low-severity conditions (log ro = 3.08 corresponding to 175 degrees c, 7.5 min, and 4.5% so2) resulted in the recovery of around 87% of the original hemicellulose component in the water-soluble stream. more than 80% of the recovered hemicellulose was in a monomeric form. as the pretreatment severity increased from 3.08 to 3.76, hemicellulose recovery dropped to 43% of the original hemicellulose found in douglas fir chips while the concentration of g ... | 1999 | 10397865 |
| characterization of a nucleopolyhedrovirus from the vapourer moth, orgyia antiqua (lepidoptera lymantriidae). | the first characterization of a nucleopolyhedrovirus (npv baculoviridae) isolated from the vapourer moth, orgyia antiqua (lepidoptera lymatriidae), in the united kingdom is presented. transmission electron microscopy revealed that the virus nucleocapsid rods were singly enveloped in the polyhedron inclusion body (pib) so that the virus is assigned to the snpv subgenus of the baculoviridae. restriction endonuclease analyses of viral dna indicated a genomic size of approximately 148 kb. restrictio ... | 1999 | 10486225 |
| stomatal behavior of four woody species in relation to leaf-specific hydraulic conductance and threshold water potential. | midday stomatal closure is mediated by the availability of water in the soil, leaf and atmosphere, but the response to these environmental and internal variables is highly species specific. we tested the hypothesis that species differences in stomatal response to humidity and soil water availability can be explained by two parameters: leaf-specific hydraulic conductance (k(l)) and a threshold leaf water potential (psi(threshold)). we used a combination of original and published data to estimate ... | 1999 | 12651540 |
| seasonal patterns of photosynthetic light response in douglas-fir seedlings subjected to elevated atmospheric co(2) and temperature. | increases in atmospheric co(2) concentration and temperature are predicted to increase the light response of photosynthesis by increasing light-saturated photosynthetic rates and apparent quantum yields. we examined the interactive effects of elevated atmospheric co(2) concentration and temperature on the light response of photosynthesis in douglas-fir (pseudotsuga menziesii (mirb.) franco) seedlings. seedlings were grown in sunlit chambers controlled to track either ambient (~400 ppm) co(2) or ... | 1999 | 12651567 |
| effects of nitrogen source on growth and activity of nitrogen-assimilating enzymes in douglas-fir seedlings. | douglas-fir (pseudotsuga menziesii (mirb.) franco) seedlings were grown for 68 days in a growth chamber in nutrient solutions with ammonium, nitrate or ammonium nitrate as the nitrogen source. among the nitrogen sources tested, whole-seedling biomass, relative growth rate (rgr), root and shoot elongation, and number of lateral roots, were greatest in seedlings grown with ammonium. in the absence of nitrogen, plant growth and formation of lateral roots were poor. initially, glutamine synthetase, ... | 1999 | 12651584 |
| the nature of lignin from steam explosion/ enzymatic hydrolysis of softwood: structural features and possible uses: scientific note. | effective utilization of the lignin by-product is a prerequisite to the commercial viability of ethanol production from softwood wastes using a steam explosion (se)/enzymatic hydrolysis (eh)/fermentation process. changes in the chemical composition of douglas fir wood on so2-catalyzed se followed by eh were assessed using conventional analytical methods and new halogen-probe techniques. a significant solubilization of hemicelluloses was observed in the se stage, the severity of which affected su ... | 1999 | 15304705 |
| nutrition and bud removal affect biomass and nutrient allocation in douglas-fir and western red cedar. | seedlings of douglas-fir (pseudotsuga menziesii (mirb.) franco) and western red cedar (thuja plicata j. donn ex d. don) were grown at high (250 mg l(-1)) and low (20 mg l(-1)) nitrogen (n) supply for a year. before the second growing season, half of the seedlings in each nutrient treatment were allocated to the other treatment. half of the seedlings in each nutrient treatment then had all growing points removed. biomass and n, phosphorus (p) and potassium (k) concentrations of old and new shoots ... | 1999 | 12651583 |
| shoot and root vulnerability to xylem cavitation in four populations of douglas-fir seedlings. | the objectives of this study were to assess the range of genotypic variation in the vulnerability of the shoot and root xylem of douglas-fir (pseudotsuga menziesii (mirb.) franco) seedlings to water-stress-induced cavitation, and to assess the trade-off between vulnerability to cavitation and conductivity per unit of stem cross-sectional area (k(s)), both within a species and within an individual tree. douglas-fir occupies a broad range of environments and exhibits considerable genetic variation ... | 1999 | 12651329 |
| biomass and nutrient allocation in douglas-fir and amabilis fir seedlings: influence of growth rate and temperature. | allocation of biomass and nutrients to current-year and one-year-old shoots and roots of two-year-old conifer seedlings with differing rates of growth was studied. differences in growth rate were achieved by selecting fast- and slow-growing populations of the relatively fast- and slow-growing conifer species, pseudotsuga menziesii (mirb.) franco and abies amabilis dougl. ex loud, respectively. environmentally controlled differences in growth rate were induced by placing half of the seedlings in ... | 1999 | 12651333 |
| species-mediated soil moisture availability and patchy establishment of pseudotsuga menziesii in chaparral. | the occurrence of mature individuals of pseudotsuga menziesii in stands of arctostaphylos species mark the initial stages of mixed evergreen forest invasion into chaparral in central coastal california. we planted two cohorts of p. menziesii seeds at three sites under stands of two arctostaphylos species and adenostoma fasciculatum in order to determine whether first-year seedling emergence and survival, particularly during the regular summer drought, underlie the spatial distribution of mature ... | 1999 | 28308157 |
| altitude trends in conifer leaf morphology and stable carbon isotope composition. | the natural ratio of stable carbon isotopes (δ(13)c) was compared to leaf structural and chemical characteristics in evergreen conifers in the north-central rockies, united states. we sought a general model that would explain variation in δ(13)c across altitudinal gradients. because variation in δ(13)c is attributed to the shifts between supply and demand for carbon dioxide within the leaf, we measured structural and chemical variables related to supply and demand. we measured stomatal density, ... | 2000 | 28308741 |
| coarse root elongation rate estimates for interior douglas-fir. | accurate estimates of root growth rates are important for root system modeling, and the spread of root systems may be an important determinant of belowground site occupancy. estimating root system growth rates is complicated because missing, discontinuous, and false annual growth rings make root cross sections difficult to age. these irregularities can occur even in roots of dominant conifers with rare or absent stem growth ring abnormalities. incomplete rings were noted in the root growth rings ... | 2000 | 12651503 |
| effects of stand composition and thinning in mixed-species forests: a modeling approach applied to douglas-fir and beech. | models estimating growth and yield of forest stands provide important tools for forest management. pure stands have been modeled extensively and successfully for decades; however, relatively few models for mixed-species stands have been developed. a spatially explicit, mechanistic model (commix) is presented that simulates growth of mixed-species forest stands, and takes account of the effects of management on stand dynamics. previously, it was shown that commix satisfactorily reproduced the dev ... | 2000 | 12651455 |
| modeling daily gas exchange of a douglas-fir forest: comparison of three stomatal conductance models with and without a soil water stress function. | modeling stomatal conductance is a key element in predicting tree growth and water use at the stand scale. we compared three commonly used models of stomatal conductance, the jarvis-loustau, ball-berry and leuning models, for their suitability for incorporating soil water stress into their formulation, and for their performance in modeling forest ecosystem fluxes. we optimized the parameters of each of the three models with sap flow and soil water content data. the optimized ball-berry model sho ... | 2000 | 12651479 |
| decreased needle longevity of fertilized douglas-fir and grand fir in the northern rockies. | changes in nutrient availability significantly affect canopy dynamics in conifers. to elucidate these effects, we experimentally fertilized mixed conifer stands at several sites across the northern rocky mountains. we measured needle longevity, total branch length and foliated length along the main branch axis, and determined mean retained cohort length on mid-canopy branches of shade-intolerant douglas-fir (pseudotsuga menziesii var. glauca (beissn.) franco) and shade-tolerant grand fir (abies ... | 2000 | 12651495 |
| temporal and spatial distribution of the nifh gene of n(2) fixing bacteria in forests and clearcuts in western oregon. | decomposition of plant litter is a primary mechanism of nutrient recycling and redistribution in most terrestrial ecosystems. previously we demonstrated by a nested pcr protocol that 20 distinctive nifh (the gene encoding nitrogenase reductase) haeiii restriction fragment length polymorphism (rflp) patterns were derived from bulk dna associated with samples of plant litter and soil collected at one douglas fir (df) forest [33]. five of the nifh dna patterns (ii-vi) were dominant types in df litt ... | 2000 | 10790513 |
| dna changes in tissues entrapped in plant resins (the precursors of amber). | there have been many reports characterizing dna from amber, which is a fossil version of plant resin. here we report an investigation of the effects of plant resin (from pseudotsuga menziesii) and drying conditions on the preservation of dna in biological tissues. we examined the degree of degradation of the dna by agarose gel electrophoresis of extracted dna, by polymerase chain reaction, and by dna sequencing. the plant resin alone appeared to cause little or no damage to dna. tissue immersed ... | 2000 | 10663137 |
| detection of a chitinase-like protein in the roots of douglas-fir trees infected with armillaria ostoyae and phellinus weirii. | protein was extracted from root bark of 11- and 25-year-old interior douglas-fir (pseudotsuga menziesii (mirb.) franco) trees that were naturally infected with armillaria ostoyae (romagnesi) herink. the proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page). root bark tissue adjacent to infected areas had a significantly higher protein concentration than healthy tissue (p < 0.05), whereas the protein concentration of infected tissue was consistently lower ... | 2000 | 12651429 |
| vertical gradients in photosynthetic light response within an old-growth douglas-fir and western hemlock canopy. | we examined needle-level light response of photosynthesis across a vertical light gradient within 45-55-m-tall western hemlock (tsuga heterophylla (raf.) sarg.) and douglas-fir (pseudotsuga menziesii (mirb.) franco) trees growing in a 400-500-year-old mixed species stand. we determined: (1) whether light-saturated photosynthetic rates, light compensation points, and respiration rates varied from the upper to the lower canopy, and (2) if light-saturated photosynthetic rates, light compensation po ... | 2000 | 12651440 |
| light absorption and bole volume growth of individual douglas-fir trees. | empirical growth and yield models for forest management are evolving toward individual-tree models that are capable of simulating the growth of mixed and uneven-aged stands. spatially explicit (i.e., distance-dependent) models usually modify the growth of trees by means of competition indices; however, these competition indices rarely simulate the light available for tree growth explicitly. we used tree growth data from an even-aged, unthinned, 50-year-old douglas-fir (pseudotsuga menziesii (mir ... | 2000 | 12651448 |
| regulation of nadph-cytochrome p450 reductase expressed during douglas-fir germination and seedling development. | nadh-cytochrome p450 is a key enzyme that transfers electrons from nadph to the cytochrome p450 family of enzymes. to begin to determine the regulation of cpr gene expression and enzyme activity in douglas-fir a full-length cdna was isolated from a seedling lambda zap cdna library and the orf was used to develop a synthetic cpr-peptide-based antiserum. northern blot analysis indicated cpr expression was regulated both developmentally prior to seed maturation and during germination, and different ... | 2000 | 11117258 |
| a reciprocal relationship between the genetic diversity at two metabolically-linked isozyme loci in several conifer species. | in the context of a general survey on genetic variation of isozyme-gene systems which function in the carbohydrate degradation and conversion, we detected a reciprocal relationship between genetic diversity at the hexokinase (hek-a) and phosphoglucose isomerase (pgi-b) loci in scots pine populations. further studies on norway spruce, douglas-fir and siberian stone pine revealed that this relationship appears to be a more general phenomenon in conifers such that increasing diversity at one locus ... | 2000 | 11519876 |
| morphology and stomatal function of douglas fir needles exposed to climate change: elevated co2 and temperature. | climate change may have an impact on the productivity of conifer trees by influencing the morphology (size and surface characteristics) and function (capacity for gas exchange) of conifer needles. in order to test the responses of needles to climatic variables, douglas fir (pseudotsuga menziesii [mirb.] franco), saplings were grown in sunlit controlled environment chambers at ambient or elevated (+200 parts per million above ambient) co2 and at ambient or elevated temperature (+4 degrees c above ... | 2000 | 10648202 |
| carbon and nitrogen allocation to male and female reproduction in rocky mountain douglas-fir (pseudotsuga menziesii var. glauca, pinaceae). | we measured carbon (respiration, photosynthesis, and production) and nitrogen allocation to male and female cones of rocky mountain douglas-fir (pseudotsuga menziesii var. glauca) to quantify gender-specific: (1) resource allocation to reproduction, and (2) contribution to carbon costs of reproduction via photosynthesis. we also measured foliar photosynthesis and nitrogen concentration ([n]) near and far from female cones to examine the relationship between reproduction and foliar physiology. ov ... | 2000 | 10766726 |
| studies into abstract properties of individuals. iv. emergence in different aged needle primordia of douglas fir. | young, middle aged and older douglas fir needle primordia, as determined by distance from the apical meristem, were measured and analyzed to compare levels and patterns of emergence related to development time. emergence was seen in the differently aged needle primordia, generally most noticeable in the oldest and the least apparent in the youngest. there was also a negative relationship between variation in size and degree of emergence, and a positive one with variation in organization. the inc ... | 2000 | 10785317 |
| steam pretreatment of douglas-fir wood chips. can conditions for optimum hemicellulose recovery still provide adequate access for efficient enzymatic hydrolysis? | douglas-fir sapwood and heartwood were impregnated with so2 and steam exploded at three severity levels, and the cellulose-rich, water-insoluble component was enzymatically hydrolyzed. the high-severity conditions resulted in near complete solubilization and some degradation of hemicelluloses and a significant improvement in the efficiency of enzymatic digestibility of the cellulose component. at lower severity, some of the hemicellulose remained unhydrolyzed, and the cellulose present in the pr ... | 2000 | 10849828 |
| discrimination and identification of coastal douglas-fir clones using needle flavonoid fingerprints. | this paper describes a method for discriminating and identifying 10 successful douglas-fir (pseudotsuga menziesii var. menziesii) clones using foliar flavonoids. all the 101 individuals analyzed by high performance liquid chromatography contained two proanthocyanidins: prodelphinidin and procyanidin and six flavonols: myricetin, quercetin, larycitrin, kaempferol, isorhamnetin and syringetin, but in different proportions. the experimental protocol used was very reproducible since the variation co ... | 2000 | 10856635 |
| impact of leptoglossus occidentalis (hemiptera: coreidae) on douglas-fir seed production. | we investigated the effect of feeding by the western conifer-seed bug, leptoglossus occidentalis heidemann, on seed production in developing cones of coastal douglas-fir, pseudostuga menziesii (mirb.) franco, with respect to seed bug life stage and sex (nymphs, adult females, and adult males) and timing of feeding (early, mid-, and late season cone development). feeding by females on caged cones for a 2-wk period during late season cone development reduced the proportion of full seeds in cones b ... | 2000 | 11057716 |
| characterization and expression of the douglas-fir luminal binding protein (pmbip). | the endoplasmic reticulum (er) molecular chaperone, bip, plays a role in the cotranslational translocation and subsequent folding and assembly of newly synthesized proteins targeted to the er and secretory pathway. the sequence encoding a douglas-fir (pseudotsuga menziesii [mirb] franco) bip homologue (pmbip) was identified by differential screening of a seedling cdna library. southern blotting indicated that pmbip is most likely present as a single copy. the deduced amino acid sequence of pmbip ... | 2000 | 11219582 |
| relationship between carbohydrate concentration and root growth potential in coniferous seedlings from three climates during cold hardening and dehardening. | greenhouse-cultured, container-grown seedlings of aleppo pine (pinus halepensis mill.), radiata pine (pinus radiata d. don), and interior douglas-fir (pseudotsuga menziesii var. glauca (beissn.) franco) were cold acclimated and deacclimated in growth chambers over 24 weeks. needle and root cold hardiness and root growth potential (rgp) were measured weekly. root, needle and stem analyses for soluble sugars and starch were performed biweekly. in all tissues, there was a close correspondence betwe ... | 2000 | 11269961 |
| effect of feeding by the western conifer seed bug, leptoglossus occidentalis, on the major storage reserves of developing seeds and on seedling vigor of douglas-fir. | the impact of feeding by the western conifer seed bug (leptoglossus occidentalis heidemann) on storage reserves of developing seeds of douglas-fir (pseudostuga menziesii (mirb.) franco) was studied by caging nymphal and adult seed bugs on cones during late-season development, and nymphs on cones during early, mid- and late-season development. analysis of the major storage reserves of partially damaged seeds revealed that late-season feeding by each life stage and feeding by nymphs at all three s ... | 2001 | 11340049 |
| characterization of proteinase activity in stratified douglas-fir seeds. | we investigated the effect of stratification on the proteinase activity involved in mobilization of the major soluble approximately 45 kda storage protein during germination of douglas-fir (pseudotsuga menziesii (mirb.) franco) seeds. complete hydrolysis of the approximately 45 kda protein was observed approximately 7 days after exposure of stratified seeds to germination conditions. coincident with the onset of mobilization, proteinase activity was detected primarily in microsomal extracts from ... | 2001 | 11390307 |
| the genetic structures of a range of douglas-fir provenance collections after planting in different european countries, assessed with two biochemical marker systems. | genetic diversities of douglas-fir provenance trials planted on several european sites were compared using both isozyme and terpene markers. a principal coordinate analysis based on similarity coefficients calculated from isozyme data indicated that, with the exception of two populations, differences between populations were small. there were no consistent trends in the variation in allele frequencies between populations. most populations contained an excess of homozygotes, perhaps due to high s ... | 2001 | 11412951 |
| fatty acid composition of pinaceae as taxonomic markers. | following our previous review on pinus spp. seed fatty acid (fa) compositions, we recapitulate here the seed fa compositions of larix (larch), picea (spruce), and pseudotsuga (douglas fir) spp. numerous seed fa compositions not described earlier are included. approximately 40% of all picea taxa and one-third of larix taxa have been analyzed so far for their seed fa compositions. qualitatively, the seed fa compositions in the three genera studied here are the same as in pinus spp., including in p ... | 2001 | 11432455 |
| diversity and genetic structure in populations of pseudotsuga menziesii (pinaceae) at chloroplast microsatellite loci. | genetic variation was compared between uniparentally-inherited (chloroplast simple sequence repeats, cpssrs) vs. biparentally-inherited (isozyme and random amplified polymorphic dna, rapd) genetic markers in douglas-fir (pseudotsuga mensiezii) from british columbia. three-hundred twenty-three individuals from 11 populations were assayed. in douglas-fir, the cpssr primer sites were well-conserved relative to pinus thunbergii (11 of 17 loci clearly amplified), but only 3 loci were appreciably poly ... | 2001 | 11444691 |
| family differences in height growth and photosynthetic traits in three conifers. | we investigated variation in height growth, gas exchange, chlorophyll fluorescence and leaf stable carbon isotope ratio among wind-pollinated progenies of douglas-fir (pseudotsuga menziesii (mirb.) franco var. glauca), ponderosa pine (pinus ponderosa dougl. ex laws.) and western white pine (pinus monticola dougl. ex d. don) from a small group of contiguous stands on the priest river experimental forest in northern idaho. photosynthetic variables differed between height classes in the pines, but ... | 2001 | 11470658 |
| time-series analysis of delta13c from tree rings. i. time trends and autocorrelation. | univariate time-series analyses were conducted on stable carbon isotope ratios obtained from tree-ring cellulose. we looked for the presence and structure of autocorrelation. significant autocorrelation violates the statistical independence assumption and biases hypothesis tests. its presence would indicate the existence of lagged physiological effects that persist for longer than the current year. we analyzed data from 28 trees (60-85 years old; mean = 73 years) of western white pine (pinus mon ... | 2001 | 11581016 |
| foliar nitrogen concentrations and natural abundance of (15)n suggest nitrogen allocation patterns of douglas-fir and mycorrhizal fungi during development in elevated carbon dioxide concentration and temperature. | pseudotsuga menziesii (mirb.) franco (douglas-fir) seedlings were grown in a 2 x 2 factorial design in enclosed mesocosms at ambient temperature or 3.5 degrees c above ambient, and at ambient co2 concentration ([co2]) or 179 ppm above ambient. two additional mesocosms were maintained as open controls. we measured the extent of mycorrhizal infection, foliar nitrogen (n) concentrations on both a weight basis (%n) and area basis (narea), and foliar delta15n signatures (15n/14n ratios) from summer 1 ... | 2001 | 11581018 |
| anchored reference loci in loblolly pine (pinus taeda l.) for integrating pine genomics. | anchored reference loci provide a framework for comparative mapping. they are landmarks to denote conserved chromosomal segments, allowing the synthesis of genetic maps from multiple sources. we evaluated 90 expressed sequence tag polymorphisms (estps) from loblolly pine (pinus taeda l.) for this function. primer sets were assayed for amplification and polymorphism in six pedigrees, representing two subgenera of pinus and a distant member of the pinaceae, douglas-fir (pseudotsuga menziesii [mirb ... | 2001 | 11606554 |
| antimicrobial activity of some pacific northwest woods against anaerobic bacteria and yeast. | extracts of woods commonly used for animal bedding were tested for antimicrobial activity. essential oils from alaska cedar (chamaecyparis nootkatensis), western juniper (juniperus occidentalis) and old growth douglas fir (pseudotsuga menziesii) as well as methanol extracts of wood from these trees plus western red cedar (thuja plicata) and ponderosa pine (pinus ponderosa) were tested for antimicrobial activity against anaerobic bacteria and yeast. the test microbes included fusobacterium necrop ... | 2001 | 11746838 |
| specific biochemical marker-based techniques for the identification of damage to douglas-fir seed resulting from feeding by the western conifer seed bug, leptoglossus occidentalis heidemann (hemiptera: coreidae). | specific biochemical marker-based techniques were tested for their ability to distinguish between seeds of douglas-fir, pseudotsuga menziesii (mirbel) franco, that were filled or unfilled (aborted) at maturity and those that were damaged or emptied by the western conifer seed bug, leptoglossus occidentalis heidemann. a polyclonal antibody raised against salivary gland extracts from l. occidentalis successfully identified residual salivary proteins on western blots containing proteins from dougla ... | 2001 | 11267911 |
| effect of oxygen delignification on the rate and extent of enzymatic hydrolysis of lignocellulosic material. | in this study, we examined the effect of oxygen delignification on the rate and extent of enzymatic hydrolysis (using commercial cellulase and beta-glucosidase) of a number of lignocellulosic substrates, including kraft pulp (model substrate), pulp mill primary clarifier sludge (pcs) and steam-exploded douglas fir chips. oxygen delignification removed up to 67% of the lignin from softwood pulp and improved the rate of, and yield from, hydrolysis by up to 111% and 174%, respectively. glucose yiel ... | 2001 | 11480919 |
| decomposition and nitrogen mineralization from biosolids and other organic materials: relationship with initial chemistry. | biosolids are effective forest fertilizers. in order to facilitate their use it is important that one be able to predict the amount and rate of mineralization of nutrients, particularly nitrogen, and the relationship between substrate chemistry and n release. we examined the relationships between substrate quality and nitrogen release in a variety of organic materials. rates of decomposition and net n mineralization from four biosolids, wheat straw, paper fines, and douglas-fir [pseudotsuga menz ... | 2001 | 11476519 |
| induced compression wood formation in douglas fir (pseudotsuga menziesii) in microgravity. | in the microgravity environment of the space shuttle columbia (life and microgravity mission sts-78), were grown 1-year-old douglas fir and loblolly pine plants in a nasa plant growth facility. several plants were harnessed (at 45 degrees ) to establish if compression wood biosynthesis, involving altered cellulose and lignin deposition and cell wall structure would occur under those conditions of induced mechanical stress. selected plants were harnessed at day 2 in orbit, with stem sections of s ... | 2001 | 11423136 |
| do enzymatic hydrolyzability and simons' stain reflect the changes in the accessibility of lignocellulosic substrates to cellulase enzymes? | in an attempt to elucidate the impact of substrate accessibility to cellulases on the susceptibility of lignocellulosic substrates to enzymatic hydrolysis, a hydrogen peroxide treated, douglas fir kraft pulp was dried using several methods with varying levels of intensity. oven-drying at 50 and 100 degrees c, air-drying, and freeze-drying methods were employed to remove the interfibrillar water from the pulp samples. subsequently, the never-dried and variably dried pulps were hydrolyzed using a ... | 2001 | 11735439 |
| mechanisms of douglas-fir resistance to western spruce budworm defoliation: bud burst phenology, photosynthetic compensation and growth rate. | we compared growth rates among mature interior douglas-fir (pseudotsuga menziesii var. glauca (beissn.) franco) trees showing resistance or susceptibility to defoliation caused by western spruce budworm (choristoneura occidentalis freeman), and among clones and half-sib seedling progeny of these trees in a greenhouse. we also investigated bud burst phenology and photosynthetic responses of clones to budworm defoliation in greenhouse experiments. resistant mature trees had a higher radial growth ... | 2001 | 11600338 |
| angiosperm bark volatiles disrupt response of douglas-fir beetle, dendroctonus pseudotsugae, to attractant-baited traps. | antennally active, bark-derived, angiosperm volatiles were tested singly and in groups for their ability to disrupt the response of the douglas-fir beetle (dfb), dendroctonus pseudotsugae, to attractant-baited multiple-funnel traps. one compound, conophthorin, was active alone in reducing the response of beetles to the baited traps. further experiments showed disruptive activity in two aliphatic green-leaf alcohols [1-hexanol and (z)-3-hexen-1-ol], as well as guaiacol and benzyl alcohol, and thr ... | 2001 | 14768811 |
| how do water transport and water storage differ in coniferous earlywood and latewood? | the goal of this research project was to determine the water transport behaviour of earlywood versus latewood in the trunk of 21-year-old douglas-fir [pseudostuga menziesii (mirb.) franco] trees. specific conductivity (k(s)) and the vulnerability of xylem to embolism were measured on a single growth ring and in a subset of earlywood and latewood samples within the same ring. earlywood/latewood ratio, trunk water potential (psi) and relative water content (rwc) were used to predict differences in ... | 2002 | 12432029 |
| belowground carbon pools and processes in different age stands of douglas-fir. | forest floor material and soil organic matter may act as both a source and a sink in global co2 cycles. thus, the ecosystem processes controlling these pools are central to understanding the transfers of carbon (c) between the atmosphere and terrestrial systems. to examine these ecosystem processes, the effect of stand age on temporal carbon source-sink relationships was examined in 20-year-old, 40-year-old and old-growth stands of douglas-fir (pseudotsuga menziesii (mirb.) franco) in the cascad ... | 2002 | 11830416 |
| influence of mixing regime on enzymatic saccharification of steam-exploded softwood chips. | in an attempt to elucidate the effect of reduced mixing on the enzymatic hydrolysis of lignocellulosic feedstocks, a pretreated softwood substrate was hydrolyzed under various mixing regimes using a commercial cellulase mixture. the substrate was generated by so2-catalyzed steam explosion of douglas fir wood chips followed by alkali-peroxide treatment to remove lignin. three mixing regimes were tested; continuous mixing at low (25 rpm) and high (150 rpm) speeds, and mixing at low-speed intersper ... | 2002 | 12018272 |
| effects of artificial and western spruce budworm (lepidoptera: tortricidae) defoliation on growth and biomass allocation of douglas-fir seedlings. | artificial defoliation has been used commonly to simulate defoliation by insect herbivores in experiments, in spite of the fact that obvious differences exist between clipping foliage and natural defoliation due to insect feeding. we used a greenhouse experiment to compare the effects of artificial and western spruce budworm (choristoneura occidentalis freeman) defoliation on the growth and biomass allocation of 3-yr old half-sib seedlings from mature douglas-fir [pseudotsuga menziesii (mirb.) f ... | 2002 | 12076004 |
| an investigation of hydraulic limitation and compensation in large, old douglas-fir trees. | the hydraulic limitation hypothesis (ryan and yoder 1997) proposes that leaf-specific hydraulic conductance (kl) and stomatal conductance (gs) decline as trees grow taller, resulting in decreased carbon assimilation. we tested the hydraulic limitation hypothesis by comparison of canopy-dominant douglas-fir (pseudotsuga menziesii var. menziesii (mirb.) franco) trees in stands that were approximately 15 m (20 years old), 32 m (40 years old) and 60 m (> 450 years old) tall in wind river, washington ... | 2002 | 12184980 |
| parameterizing a model of douglas fir water flow using a tracheid-level model. | the theory of tree water flow proposed in aumann & ford (submitted) is assessed by numerically solving the model developed from this theory under a variety of functional parameterizations. the unknown functions in this nonlinear partial differential equation model are determined using a tracheid-level model of water flow in a block of douglas fir tracheids. the processes of flow, cavitation, pit aspiration/deaspiration, flow through the cell wall and ray exudation in a block of approximately 79 ... | 2002 | 12425978 |
| canopy and hydraulic conductance in young, mature and old douglas-fir trees. | we tested for reductions in water transport with increasing tree size, a key component in determining whether gas exchange and growth are hydraulically limited in tall trees. during the summers of 1998 and 1999, we measured water transport with granier-type, constant-heat sap flow probes, vapor pressure deficit, and leaf and soil water potentials in overstory pseudotsuga menziesii (mirb.) franco trees in three stands differing in size and age (15, 32 and 60 m in height and about 20, 40 and 450 y ... | 2002 | 11830417 |
| trends in bole biomass accumulation, net primary production and tree mortality in pseudotsuga menziesii forests of contrasting age. | although it is generally accepted that the rate of accumulation of biomass declines as forests age, little is known about the relative contributions to this decline of changes in net primary production (npp) and tree mortality. we used 10-15 years of observations of permanent plots in three small watersheds in and near the h.j. andrews experimental forest, oregon, to examine these issues. the three watersheds are of similar elevation and potential productivity and support young (29 years at last ... | 2002 | 11830418 |
| alteration of foliar flavonoid chemistry induced by enhanced uv-b radiation in field-grown pinus ponderosa, quercus rubra and pseudotsuga menziesii. | chromatographic analyses of foliage from several tree species illustrate the species-specific effects of uv-b radiation on both quantity and composition of foliar flavonoids. pinus ponderosa, quercus rubra and pseudotsuga menziesii were field-grown under modulated ambient (1x) and enhanced (2x) biologically effective uv-b radiation. foliage was harvested seasonally over a 3-year period, extracted, purified and the flavonoid fraction applied to a mu bondapak/c(18) column hplc system sampling at 2 ... | 2002 | 11897512 |
| breakage of pseudotsuga menziesii seed dormancy by cold treatment as related to changes in seed aba sensitivity and aba levels. | the main aims of the present work were to investigate whether a chilling treatment which breaks dormancy of douglas fir (pseudotsuga menziesii (mirb.) franco) seeds induces changes in the sensitivity of seeds to exogenous aba or in aba levels in the embryo and the megagametophyte, and whether these changes are related to the breaking of dormancy. dormant seeds germinated very slowly within a narrow range of temperatures (20-30 degrees c), the thermal optimum being approximately 25 degrees c. the ... | 2002 | 11903979 |
| effects of phloem girdling in conifers on apical control of branches, growth allocation and air in wood. | we investigated effects of stem phloem girdles on apical control of branch angle, stem and branch growth and stem air content in six conifer species. a stem girdle 2 cm above a branch caused the branch to bend upward in all six species. upward bending was associated with increased formation and action of compression wood (cw) in the lower portion of the branch. compression wood also formed in the main stem below the branch, suggesting increased auxin production in the branch. a stem girdle 2 cm ... | 2002 | 11960759 |
| scar markers to detect mycorrhizas of an american laccaria bicolor strain inoculated in european douglas-fir plantations. | the american strain s238n of the ectomycorrhizal fungus laccaria bicolor (maire) orton has been used to inoculate douglas-fir [pseudotsuga menziesii (mir.) franco] plantations in france over the last two decades. laccaria fruit bodies are scarce in mature plantations, which precludes further assessment of its persistence by fruit body surveys. our objective was to develop new markers to identify this strain and its eventual non-fruiting progeny on root tips. we converted nine random amplified po ... | 2002 | 11968943 |
| cellulase adsorption and an evaluation of enzyme recycle during hydrolysis of steam-exploded softwood residues. | the sugar yield and enzyme adsorption profile obtained during the hydrolysis of so2-catalyzed steam-exploded douglas-fir and posttreated steam-exploded douglas-fir substrates were determined. after hot alkali peroxide posttreatment, the rates and yield of hydrolysis attained from the posttreated douglas-fir were significantly higher, even at lower enzyme loadings, than those obtained with the corresponding steam-exploded douglas-fir. the enzymatic adsorption profiles observed during hydrolysis o ... | 2002 | 12018289 |
| enhancing the enzymatic hydrolysis of cellulosic materials using simultaneous ball milling. | one of the limiting factors restricting the effective and efficient bioconversion of softwood-derived lignocellulosic residues is the recalcitrance of the substrate following pretreatment. consequently, the ensuing enzymatic process requires relatively high enzyme loadings to produce monomeric carbohydrates that are readily fermentable by ethanologenic microorganisms. in an attempt to circumvent the need for larger enzyme loadings, a simultaneous physical and enzymatic hydrolysis treatment was e ... | 2002 | 12018304 |
| the role of monoterpenes in resistance of douglas fir to western spruce budworm defoliation. | we conducted defoliation experiments with 7- to 8-year-old clones of douglas fir [pseudotsuga menziesii (mirb.) franco var. glauca] to assess the role of monoterpenes as a resistance mechanism to western spruce budworm (choristoneura occidentalis freeman) defoliation. the grafted clones were derived from mature trees that showed resistance or susceptibility to budworm defoliation in the forest. all clones were exposed to either budworm defoliation or nondefoliation treatments in 1998 and 1999 un ... | 2002 | 12049230 |
| photosynthetic differences between saplings and adult trees: an integration of field results by meta-analysis. | ontogenetic changes in gas exchange parameters provide both insight into mechanisms underlying tree growth patterns, and data necessary to scale environmental impacts on young trees to predict responses of older trees. we present a quantitative review and meta-analysis of field measurements of gas exchange parameters in saplings and mature trees of 35 tree species (seven conifers, seven temperate deciduous trees, and 21 tropical evergreen trees). data for saplings were obtained in both understor ... | 2002 | 11830408 |
| response of old-growth conifers to reduction in stand density in western oregon forests. | the positive growth response of healthy young trees to density reduction is well known. in contrast, large old trees are usually thought to be intrinsically limited in their ability to respond to increased growing space; therefore, density reduction is seldom used in stands of old-growth trees. we tested the null hypothesis that old-growth trees are incapable of responding with increased growth following density reduction. the diameter growth response of 271 douglas-fir (pseudotsuga menziesii (m ... | 2002 | 11830410 |
| canopy light transmittance in douglas-fir--western hemlock stands. | we measured vertical and horizontal variation in canopy transmittance of photosynthetically active radiation in five pseudotsuga menziesii (mirb.) franco-tsuga heterophylla (raf.) sarg. (douglas-fir-western hemlock) stands in the central cascades of southern washington to determine how stand structure and age affect the forest light environment. the shape of the mean transmittance profile was related to stand height, but height of mean maximum transmittance was progressively lower than maximum t ... | 2002 | 11830411 |
| age- and position-related changes in hydraulic versus mechanical dysfunction of xylem: inferring the design criteria for douglas-fir wood structure. | we do not know why trees exhibit changes in wood characteristics as a function of cambial age. in part, the answer may lie in the existence of a tradeoff between hydraulic properties and mechanical support. in conifers, longitudinal tracheids represent 92% of the cells comprising the wood and are involved in both water transport and mechanical support. we used three hydraulic parameters to estimate hydraulic safety factors at several vertical and radial locations in the trunk and branches: vulne ... | 2002 | 11830406 |
| elution rate and spacing of antiaggregation pheromone dispensers for protecting live trees from dendroctonus pseudotsugae (coleoptera: scolytidae). | the antiaggregation pheromone 3-methylcyclohex-2-en-1-one (mch) is highly effective in preventing the infestation of high-risk trees by douglas-fir beetle, dendroctonus pseudotsugae hopkins. a large portion of the cost of an mch treatment is related to the time applicators spend walking through an area dispersing the formulated pheromone. application of fewer mch dispensers eluting at a higher rate than those currently registered for operational use could potentially reduce treatment costs. two ... | 2002 | 12216820 |
| measuring positive, negative, and null impacts of forest disturbances: a case study using dwarf mistletoe on douglas fir. | not all disease activity causes an impact. not all impacts are negative. the aim of this study was to examine a method that could conceptually specify when impacts occur and that could quantify both negative and positive disease impacts. for this study, dwarf mistletoe ( arceuthobium douglasi) of douglas fir ( pseudotsuga menziesii) in southwestern oregon was used as a case study. the method uses six variables for forest growth, mortality, and stand structure, and six categorical disease severit ... | 2002 | 12402094 |
| hydraulic redistribution of soil water during summer drought in two contrasting pacific northwest coniferous forests. | the magnitude of hydraulic redistribution of soil water by roots and its impact on soil water balance were estimated by monitoring time courses of soil water status at multiple depths and root sap flow under drought conditions in a dry ponderosa pine (pinus ponderosa dougl. ex laws) ecosystem and in a moist douglas-fir (pseudotsuga menziesii (mirb.) franco) ecosystem. the fate of deuterated water applied to small plots to create a strong horizontal soil water potential gradient was also monitore ... | 2002 | 12414370 |
| the influence of bark on the fermentation of douglas-fir whitewood pre-hydrolysates. | douglas-fir ( pseudotsuga menziesii) whitewood was supplemented with increasing concentrations of bark (0-30%) and was pretreated using so(2)-catalysed steam explosion. the presence of bark in the feedstock resulted in the decreased recovery of total sugars, furfural and 5-hydroxymethylfurfural in the resultant pre-hydrolysate. no detrimental impact on monomer sugar recovery was observed. the concentration of lipophilic extractives present in the pre-hydrolysate increased with increasing bark lo ... | 2002 | 12172607 |
| the douglas-fir bip promoter is functional in arabidopsis and responds to wounding. | a dna sequence representing the promoter region of the douglas-fir (pseudotsuga menziesii [mirb.] franco) luminal binding protein pmbip (pmbippro1) was isolated using inverse polymerase chain reaction (ipcr). transient expression analysis of pmbippro1 fused to the beta-glucuronidase (gus) reporter gene demonstrated that this promoter is functional in germinating douglas-fir embryos. transgenic arabidopsis plants containing pmbippro1:gus reporter gene constructs revealed strong staining associate ... | 2002 | 12172839 |
| enhanced tolerance of photosynthesis to high-light and drought stress in pseudotsuga menziesii seedlings grown in ultraviolet-b radiation. | we investigated the effects of an ambient dose of ultraviolet-b (uv-b) radiation on chamber-grown pseudotsuga menziesii var. glauca (beissn.) franco (douglas-fir) seedlings, to determine if the presence of uv-b radiation in the growth light regime induces tolerance to environmental stresses such as high light and drought. douglas-fir seedlings were grown without uv-b radiation or with 6 kj m-2 day-1 of biologically effective uv-b, which is ambient for the intermountain regions of idaho. non-stre ... | 2002 | 12184972 |
| (z,z)-4,7-tridecadien-(s)-2-yl acetate: sex pheromone of douglas-fir cone gall midge, contarinia oregonensis. | our objectives were to identify and field test the sex pheromone of female douglas-fir cone gall midge, contarinia oregonensis (diptera: ce-cidomyiidae). coupled gas chromatographic-electroantennographic detection (gc-ead) analyses of pheromone extract revealed a single compound (a) that elicited responses from male antennae. hydrogenation of pheromone extract, followed by renewed gc-ead analysis, revealed a new ead-active compound with chromatographic characteristics identical to those of tride ... | 2002 | 12523568 |
| use of a physiological process model with forestry yield tables to set limits on annual carbon balances. | we present an approach that sets limits on annual carbon fluxes for different aged forests by using a simple process-based model (3-pg) and information derived from yield tables and local weather stations. given a measure of height-growth potential, model predictions are constrained to match stand dynamics described in yield tables. thus constrained, the model can provide reasonable annual estimates of gross photosynthesis under a specified climate, even with inexact knowledge of soil properties ... | 2002 | 11830414 |
| needle anatomy changes with increasing tree age in douglas-fir. | morphological differences between old-growth trees and saplings of douglas-fir (pseudotsuga menziesii (mirb.) franco) may extend to differences in needle anatomy. we used microscopy with image analysis to compare and quantify anatomical parameters in cross sections of previous-year needles of old-growth douglas-fir trees and saplings at the wind river canopy crane site in washington and at three sites in the cascade mountains of oregon. we also compared needle anatomy across a chronosequence of ... | 2002 | 11830409 |
| biophysical controls of carbon flows in three successional douglas-fir stands based on eddy-covariance measurements. | we measured net carbon flux (f(co2)) and net h2o flux (f(h2o)) by the eddy-covariance method at three douglas-fir (pseudotsuga menziesii (mirb.) franco)-western hemlock (tsuga heterophylla (raf.) sarg.) sites located in the wind river valley of southern washington state, usa. stands were approximately 20, 40 and 450 years old and measurements were made between june 15 and october 15 of 1998 in the 40- and 450-year-old stands, and of 1999 in the 20- and 450-year-old stands. our objectives were to ... | 2002 | 11830413 |
| variation in specific needle area of old-growth douglas-fir in relation to needle age, within-crown position and epicormic shoot production. | variation in specific needle area (sna; cm2 projected fresh needle area g-1 oven-dried needle weight) was investigated in relation to needle age, within-crown position and epicormic shoot production in 450-year-old douglas-fir (pseudotsuga menziesii mirb. (franco) var. menziesii) trees. specific needle area decreased with increasing needle age. the magnitude and rate of change in sna with needle age were greatest for lower-crown branches, and decreased toward the middle- and upper-crown branches ... | 2002 | 11772553 |
| fast and efficient alkaline peroxide treatment to enhance the enzymatic digestibility of steam-exploded softwood substrates. | the enzymatic digestibility of steam-exploded douglas-fir wood chips (steam exploded at 195 degrees c, 4.5 min, and 4.5% (w/w) so(2)) was significantly improved using an optimized alkaline peroxide treatment. best hydrolysis yields were attained when the steam-exploded material was post-treated with 1% hydrogen peroxide at ph 11.5 and 80 degrees c for 45 min. this alkaline peroxide treatment was applied directly to the water-washed, steam-exploded material eliminating the need for independent al ... | 2002 | 11807763 |
| 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 |
| 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 |
| 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 |
| freezing tolerance of conifer seeds and germinants. | survival after freezing was measured for seeds and germinants of four seedlots each of interior spruce (picea glauca x engelmannii complex), lodgepole pine (pinus contorta dougl. ex loud.), douglas-fir (pseudotsuga menziesii (mirb.) franco) and western red cedar (thuja plicata donn ex d. donn). effects of eight seed treatments on post-freezing survival of seeds and germinants were tested: dry, imbibed and stratified seed, and seed placed in a growth chamber for 2, 5, 10, 15, 20 or 30 days in a 1 ... | 2003 | 14652223 |
| copper, zinc, and arsenic in soil surrounding douglas-fir poles treated with ammoniacal copper zinc arsenate (acza). | the levels of copper, zinc, and arsenic in soil surrounding douglas-fir [pseudotsuga menziesii (mirb.) franco] utility poles treated with ammoniacal copper zinc arsenate (acza) were investigated at sites in florida, virginia, and new york. copper levels were elevated near the poles and declined with both horizontal distance away from the pole and depth beneath the soil surface. zinc levels were also elevated next to the poles, but the levels declined more slowly than did those of copper. arsenic ... | 2003 | 14674531 |
| a new approach for estimating the labile aluminium fraction in soil solutions, through batch experiments, using cationic (amberlite ir 120) or non ionic (amberlite xad 2) resins. | aluminium fractionation was tested on two types of resin. the first approach was based on the selective sorption of cationic forms on a strong cation exchange resin (amberlite ir 120) which is commonly used. using a defined contact time (1 hour) between solution and resin (batch technique) it was possible to obtain separation between different aluminium species. the second approach was based on the sorption of organic matter, especially complexes between organic matter and aluminium, onto a non ... | 2003 | 14733391 |
| the potential role of ectomycorrhizal fungi in determining douglas-fir resistance to defoliation by the western spruce budworm (lepidoptera: tortricidae). | there is phenotypic variation among individual trees of interior douglas-fir (pseudotsuga menziesii var. glauca [beissn.] franco) in their resistance to defoliation by the western spruce budworm (choristoneura occidentalis freeman). we evaluated the potential role of ectomycorrhizal fungi in determining this resistance using half-sib seedlings derived from parent trees that are resistant versus susceptible to budworm defoliation in the field. the seedlings were inoculated with laccaria bicolor e ... | 2003 | 12852617 |
| responses of gas exchange to reversible changes in whole-plant transpiration rate in two conifer species. | this study examined the autonomy of branches with respect to the control of transpiration (e) in douglas-fir (pseudotsuga menziesii (mirb.) franco) and western red cedar (thuja plicata donn) seedlings. experiments were conducted on whole seedlings in a gas exchange system with a dual-cuvette that permitted independent manipulation and measurement of e in the upper and lower cuvettes. the value of e in one cuvette was manipulated by varying vapor pressure deficit (d) between 2.2 and 0.2 kpa, wher ... | 2003 | 12865245 |
| brassinolide improves embryogenic tissue initiation in conifers and rice. | somatic embryogenesis (se), the most promising technology for the large-scale production of high-value coniferous trees from advanced breeding and genetic engineering programs, is expected to play an important role in increasing productivity, sustainability, and the uniformity of future u.s. forests. to be successful for commercial use, se technology must work with a variety of genetically diverse trees. initiation in loblolly pine ( pinus taeda l.), our main focus species, is often recalcitrant ... | 2003 | 12879262 |
| branch junctions and the flow of water through xylem in douglas-fir and ponderosa pine stems. | water flowing through the xylem from the roots to the leaves of most plants must pass through junctions where branches have developed from the main stem. these junctions have been studied as both flow constrictions and components of a hydraulic segmentation mechanism to protect the main axes of the plant. the hydraulic nature of the branch junction also affects the degree to which branches interact and can respond to changes in flow to other branches. the junctions from shoots of two conifer spe ... | 2003 | 12730265 |