Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| pollen sequence from late quaternary sediments in yellowstone park. | a radiocarbon-dated pollen diagram from a depression near the end of the southeast arm of yellowstone lake, wyoming, records the vegetation sequence from the retreat of late wisconsin (pinedale) ice to the present time. the tundra picea-abies-pinus albicaulis (spruce-fir-whitebark pine) parkland vegetation inferred during late glacial time changed rapidly to a pinus contorta (lodgepole pine) forest shortly before 11,550 carbon-14 years ago, suggesting a warming trend at that time. the pinus cont ... | 1970 | 17731592 |
| quantitative assessment of the bacterial rhizosphere flora of pinus contorta var. latifolia. | the bacterial flora associated with root systems of young and mature lodgepole pine was investigated by sampling forest-grown trees. counts were performed and expressed on a surface-area basis to give a more realistic comparison of organism density or activity within the control soil, rhizosphere soil, and rhizoplane. on this basis, densities increased by an order of 10(4)- to 10(6)-fold from control soil to rhizoplane, with the degree of stimulation being inversely related to root radius. | 1975 | 1220866 |
| characterization of the bacterial flora associated with root systems of pinus contorta var. latifolia. | root systems of young and mature lodgepole pine (pinus contorta dougl. var. latifolia englem.) were removed from forest stands and the associated aerobic bacterial flora isolated. characterization of rhizoplane and control soil isolates from these tree root systems demonstrated differences from that reported for agricultural crops. ammonifying, proteolytic, and amylolytic organisms were proportionately reduced within the rhizoplane. the rhizoplane organisms grew more slowly than the control soil ... | 1978 | 747813 |
| soil temperature influences on root resistance of pinus contorta seedlings. | the influence of low temperature in the root zone on water uptake in lodgepole pine (pinus contorta dougl. ex loud.) was studied under laboratory conditions. to remove soil hydraulic influences, two-year-old seedlings were transferred to solution cultures and maintained in temperature controlled water baths. short term measurements of leaf conductance, leaf water potential and tritiated water movement were taken at root temperatures from 22 c down to 0 c. root resistance was calculated to be 67% ... | 1980 | 16661254 |
| simulation of solar radiation absorption in vegetation canopies. | a solar radiation canopy absorption model, including multiple scattering effects, was developed and tested for a lodgepole pine (pinus contorta) canopy. reflectance above the canopy, spectral transmittance to the ground layer, and geometric and spectral measurements of canopy elements were made. relatively large differentials occurred in spectral absorption by canopy layers, especially in the photosynthetically active region, as a function of solar zenith angle. in addition, the proportion of to ... | 1980 | 20234510 |
| importance of aerodynamic resistance to water use efficiency in three conifers under field conditions. | the quantitative importance of aerodynamic resistance to h(2)o vapor and co(2) exchange was determined for shoots from saplings of three conifers (abies lasiocarpa [hook] nutt., pinus contorta dougl., juniperus communis l.) under natural conditions in the field. a combination of relatively low stomatal resistances (<300 seconds per centimeter) and low wind speeds (<30 centimeters per second) led to substantial contributions of the aerodynamic resistance (r(wv) (a)) to water use efficiency (wue = ... | 1980 | 16661128 |
| thermal ir exitance model of a plant canopy. | a thermal ir exitance model of a plant canopy based on a mathematical abstraction of three horizontal layers of vegetation was developed. canopy geometry within each layer is quantitatively described by the foliage and branch orientation distributions and number density. given this geometric information for each layer and the driving meteorological variables, a system of energy budget equations was determined and solved for average layer temperatures. these estimated layer temperatures, together ... | 1981 | 20309167 |
| the fate of fenitrothion in a stream environment and its effect on the fauna, following aerial spraying of a scottish forest. | in order to control an infestation of pine beauty moth (panolis flammea schiff.) fenitrothion was applied at a rate of 300 g ha-1 to a forest plantation consisting primarily of lodgepole pine (pinus contorta loud.) and sitka spruce (picea sitchensis carriere) using the ultra-low volume spraying technique. the concentration of fenitrothion in the forest stream rose to a maximum of 18 micrograms l-1 within the treated area an hour after spraying, but fell to 0.5 microgram l-1 after 24 hs. there wa ... | 1981 | 7280656 |
| leaf conductance as a function of photosynthetic photon flux density and absolute humidity difference from leaf to air. | for an entire season of stomatal activity, leaf or needle conductance was observed on four species, each in a different genus: engelmann spruce (picea engelmannii parry ex engelm.), subalpine fir (abies lasiocarpa [hook.] nutt.), lodgepole pine (pinus contorta var. latifolia engelm.), and aspen (populus tremuloides michx.). conductance in the natural environment was described for all species by photosynthetic photon flux density (ppfd) and absolute humidity difference from leaf to air (dah), as ... | 1982 | 16662336 |
| evaluation of season, temperature, and water stress effects on stomata using a leaf conductance model. | a model was developed earlier describing conductance for three conifers (picea engelmannii parry ex engelm., abies lasiocarpa [hook.] nutt., and pinus contorta var. latifolia engelm.) and one hardwood (populus tremuloides michx.) using only two terms, photosynthetic photon flux density (ppfd) and absolute humidity difference from leaf to air (dah). using residual analysis techniques (actual minus estimated conductance), it was determined that no seasonal or temperature effects existed that were ... | 1982 | 16662337 |
| gas chromatography-mass spectroscopy identification of 1-aminocyclopropane-1-carboxylic acid in compressionwood vascular cambium of pinus contorta dougl. | following cation and anion exchange chromatography, 1-aminocyclopropane-1-carboxylic acid (acc) was converted to the 2,4-dinitrophenyl derivative and then purified by high-performance liquid chromatography (hplc). after three hplc steps, endogenous acc was identified by gcms in the vascular cambium on the lower side of pinus contorta dougl. ssp. latifolia branches in association with compressionwood differentiation, but acc was not detected in the opposite wood cambial region on the upper sides ... | 1983 | 16662843 |
| the role of plant hormones in higher plant cellular differentiation. ii. experiments with the vascular cambium, and sclereid and tracheid differentiation in the pine, pinus contorta. | in sterile-cultured explants of stems of the pine pinus contorta dougl., fusiform cambial cells differentiated entirely into axial parenchyma cells when exogenous indol-3yl-acetic acid (iaa) was omitted. the normal appearance of the cambial zone was maintained when iaa was included in the medium. the iaa-maintained stability of cambial structure suggests physiological rather than epigenetic control over vascular cambium structure. iaa was essential for the occurrence of callus growth in stem exp ... | 1983 | 6223902 |
| autumn stomatal closure in six conifer species of the central rocky mountains. | environmental and water relations parameters during fall were monitored for six conifer tree species common to the central rocky mountains growing naturally at the same location (pinus contorta, pinus ponderosa, pinus flexilus, pseudotsuga menziesii, abies lasiocarpa, picea engelmannii). subsequent to what appeared to be the beginning of seasonal stomatal closure, leaf conductance to water vapor declined sharply following the onset of freezing air temperatures at night. a coincident rapid declin ... | 1984 | 28311019 |
| influence of shoot structure on light interception and photosynthesis in conifers. | the influence of shoot structure on net photosynthesis was evaluated under field conditions for the central rocky mountain (united states) conifers picea engelmannii (parry ex engelm.), abies lasiocarpa ([hook] nutt.), and pinus contorta (engelm.). in all species, the greater number of needles per unit stem length on sun shoots correlated with a smaller silhouette leaf area to total leaf area ratio (star). decreased star was due primarily to greater needle inclination toward the vertical, plus s ... | 1985 | 16664525 |
| physiographic, stand, and environmental effects on individual tree growth and growth efficiency in subalpine forests. | annual volume growth of subalpine trees in the central rocky mountains was studied in relation to site and stand conditions. growth of individual trees was most strongly influenced by estimated potential absorbed radiation, which varied with physiographic conditions and tree leaf area. growth efficiency was estimated by the ratio of annual volume growth to potential radiation absorption by the crown. growth efficiency was higher in young lodgepole pine (pinus contorta var. latifolia engelm.) tha ... | 1986 | 14975841 |
| stomatal responses to humidity in selected conifers. | stomatal response to changes in leaf-to-air water vapor pressure difference (d) was studied in needles of the current year's shoot of three-year-old seedlings of picea sitchensis (bong.) carr., pinus contorta dougl. ex loud., larix x eurolepis henry, and pinus sylvestris l. both eight-week- and ten-month-old shoots of p. sylvestris were studied. stomata of all the species responded by closing to some degree as d was increased over the range 0.4-2.0 kpa. ten-month-old shoots of p. sylvestris show ... | 1986 | 14975844 |
| a dynamic model for studying flow of water in single trees. | flow of water in a single tree was modeled in terms of the darcy equation using a catena of four compartments: root, stem (further divided into discs), branches and leaves. within each compartment or disc, water content was related to both water potential and conductivity of the xylem tissue using power or logarithmic functions, thus introducing both capacitance and variable resistance to flow in the model. transpiration from the leaves to the atmosphere was used as the upper boundary to the mod ... | 1986 | 14975885 |
| sex-specific production of ipsdienol and myrcenol bydendroctonus ponderosae (coleoptera: scolytidae) exposed to myrcene vapors. | male mountain pine beetles,dendroctonus ponderosae hopkins, produced ipsdienol [97.0% ± 0.3s-(+)] and myrcenol (90.3% ± 4.0e) when exposed to myrcene vapors. females which were exposed to myrcene vapors did not produce any ipsdienol, but did produce low levels of myrcenol (98.0% ± 0.7e). neither sex produced detectable levels of ipsdienol or myrcenol when fed for 24 hr on lodgepole pine,pinus contorta var.latifolia engelmann. the sex-specific conversion of myrcene to ipsdienol and myrcenol sugge ... | 1986 | 24305835 |
| biochemistry of oleoresinosis : monoterpene and diterpene biosynthesis in lodgepole pine saplings infected with ceratocystis clavigera or treated with carbohydrate elicitors. | elevated levels of monoterpenes and diterpene resin acids are produced in the stems of lodgepole pine (pinus contorta var latifolia) saplings when wounded and inoculated with the blue-stain fungus ceratocystis clavigera or when wounded and treated with a pectic fragment from tomato leaves (piif) or a fungal cell wall fragment (chitosan). this induced defensive response (hyperoleoresinosis) is the result of a transient rise in the ability to biosynthesize cyclic monoterpenes and diterpene resin a ... | 1987 | 16665815 |
| investigations on the nature of the auxin-wave in the cambial region of pine stems : validation of iaa as the auxin component by the avena coleoptile curvature assay and by gas chromatography-mass spectrometry-selected ion monitoring. | the major auxin of scots pine (pinus silvestris l.) which is transported basipetally into agar strips from the cambial region of the stem was quantified by the went avena coleoptile curvature assay before and after reversed phase c(18) high performance liquid chromatography (hplc), and then identified by full spectrum gas chromatography-mass spectrometry (gc-ms) as indole-3-acetic acid (iaa). the iaa was subsequently quantified by gc-ms-selected ion monitoring (sim) using an internal standard of ... | 1987 | 16665387 |
| linkage disequilibrium between allozymes in natural populations of lodgepole pine. | pairwise linkage disequilibrium values (d) were estimated for 14 allozyme loci in two natural populations of lodgepole pine (pinus contorta ssp. latifolia). maternal multilocus genotypes were inferred from samples of (haploid) megagametophytic seed-endosperms. coupling/repulsion double heterozygotes were distinguished for closely linked pairs of loci. assays of seven of the loci in seed embryos allowed estimates of d for these loci in the outcross pollen pool (estimates of outcrossing rates indi ... | 1987 | 17246370 |
| chloroplast dna polymorphisms in lodgepole and jack pines and their hybrids. | samples taken from throughout the ranges of distribution of lodgepole pine (pinus contorta dougl. ex. loud.) and jack pine (pinus banksiana lamb.) were assayed for sal i and sst i chloroplast dna restriction fragment variation. although the chloroplast genome is often regarded as highly conserved, at least 2 distinct sal i and 13 distinct sst i restriction fragment banding patterns occur in these closely related species. none of the chloroplast dna restriction fragment banding patterns observed ... | 1987 | 3470779 |
| young's modulus of sections of living branches and tree trunks. | young's modulus along the grain (elasticity, e) was measured on 10 sections of branches and three tree trunks, with bark, of picea sitchensis (bong.) carr., pinus contorta dougl. ex loud., larix decidua mill. and betula pendula roth. syn. verrucosa ehrh. the sections were simply supported and corrections were made for taper and deflection due to shear. the e values for trunks were at the lower end of the range reported for green timber (2.4-7.5 gpa), and those for branches were still lower (0.7- ... | 1987 | 14975919 |
| diameters and dry weights of tree shoots: effects of young's modulus, taper, deflection and angle. | the structural theory for cantilever beams was used to calculate the diameters and dry weights of wood that unbranched shoots must produce to support their own weights. the study was done on picea sitchensis (bong.) carr., pinus contorta dougl., larix decidua mill. and betula pendula roth. syn. verrucosa ehrh. the weights of wood increased in a non-linear fashion with increase in shoot length. a large investment in wood (as measured by diameter and dry weight) was required to maintain a small en ... | 1988 | 14972812 |
| effect of elemental sulphur on the vegetation of a lodgepole pine stand. | shrub and herb cover decreased 98% and diversity 76% after particulate elemental sulphur was deposited in a pinus contorta loudon var. latifolia engelm. forest in west-central alberta, canada. decreases were measured over four years and, initially, were greater for the herbs than they were for the shrubs. the decline in the herbs occurred one year before decreases in half the shrub species. the dramatic decline of the vegetation appeared related to the changes in the soil chemistry of the surfac ... | 1988 | 15092632 |
| aboveground production and n and p use by larix occidentalis and pinus contorta in the washington cascades, usa. | aboveground net primary production (anpp) and n and p use patterns were determined for western larch (larix occidentalis nutt.), a deciduous conifer, and lodgepole pine (pinus contorta dougl. var. latifolia engelm.), an evergreen conifer, in the cascade mountains of washington, usa. western larch and lodgepole pine retranslocated 87 and 66% of foliage n and 66 and 78% of foliage p, respectively. at the stand level, n use efficiency of western larch was greater than that of lodgepole pine, wherea ... | 1989 | 14972994 |
| removal of ethanol from lodgepole pine roots. | the removal of ethanol from flooded tree roots was examined in three provenances of lodgepole pine (pinus contorta) dougl. less than 0.2% of the ethanol generated by the roots escaped by the gaseous pathway provided by the lenticels. a large proportion, however, was transported from the roots in the transpiration stream. gas chromatographic detection of ethanol emanating from the lenticels provided a sensitive indicator of oxygen deficits in the roots. | 1989 | 14972998 |
| spatial autocorrelation analysis of the distribution of genotypes within populations of lodgepole pine. | spatial autocorrelation analyses of point samples within two populations of lodgepole pine (pinus contorta ssp. latifolia) indicate that single-locus mature tree and pollen genotypes are distributed in a nearly random fashion for most of the allozyme loci assayed. this lack of structure in the distributions of most genotypes is consistent with outcrossing rates that are very nearly 1.0 and with estimates indicating that both pollen and seed are dispersed over long distances in lodgepole pine. ho ... | 1989 | 2731726 |
| terpene alcohol pheromone production bydendroctonus ponderosae andips paraconfusus (coleoptera: scolytidae) in the absence of readily culturable microorganisms. | dendroctonus ponderosae hopkins andips paraconfusus lanier of both sexes produced most of their complement of terpene alcohols at normal to elevated levels in the absence of readily culturable microorganisms. however, there was some evidence that microbial involvement may be required by malei. paraconfusus to produce ipsenol and ipsdienol at normal levels. increased levels of certain terpene alcohols found in axenically reared or streptomycin-fed beetles suggest that symbiotic microorganisms may ... | 1989 | 24272090 |
| influence of male and female cones on assimilate production of pinus contorta trees within a forest stand. | studies on branches of field-grown pinus contorta dougl. trees showed that: (i) branches with fully developed male or female cones were heavier than vegetative branches; (ii) the production of female cones decreased neither the number of laterals nor the length of the terminal or lateral shoots on the cone-bearing branches; (iii) the production of male cones decreased both the number of laterals and the number of needles on the cone-bearing branches; (iv) needles on male cone-bearing branches ha ... | 1990 | 14972905 |
| the interaction between leaf longevity and shoot growth and foliar biomass per shoot in pinus contorta at two elevations. | leaf longevity ranged from an average of 5 to 18 years in individual trees of lodgepole pine (pinus contorta dougl. ssp. latifolia d.k. bailey) from six even-aged stands in central colorado, usa, of which three were at an elevation of 2800 and three at an elevation of 3200 m. leaf longevity was 38% greater and annual shoot growth increment was 33% less in trees growing at 3200 m than in trees growing at 2800 m elevation. there was no difference in leaf biomass per shoot between the trees at the ... | 1990 | 14972918 |
| characteristics of high- and low-vigor lodgepole pine trees in old-growth stands. | lodgepole pine (pinus contorta var. latifolia engelm.) trees in an old stand differed widely in appearance. some appeared healthy, with deep crowns, high leaf areas, nearly conical-shaped crown tops, and branches with live needles extending well back from the tip. others with similar-sized boles appeared to be in a state of decline, having much shallower crowns, lower leaf areas, crowns that were flattened at the top, and "tufted" branches with needles only near the ends of the branches. ten tre ... | 1990 | 14972921 |
| influence of female cones on the vegetative growth of pinus contorta trees. | branches of pinus contorta dougl. bearing two-year-old female cones initiated fewer lateral buds than vegetative branches. however, the number of lateral shoots that differentiated and grew was not reduced on female cone-bearing branches. neither the number nor the weight of female cones influenced the length of the terminal shoot. the total length of all lateral shoots was positively associated with the weight of two-year-old female cones. branch units with two-year-old female cones produced si ... | 1990 | 14972947 |
| influence of male cones on early season vegetative growth of pinus contorta trees. | on average, branches of pinus contorta dougl. bearing male cones had 35 fewer needle pairs than equivalent vegetative branches, and significantly fewer differentiated primordia (i.e., male cones + needle pairs + sterile cataphylls). it was estimated that the formation of male cones results in a 27-50% reduction in the number of needles per male cone-bearing branch. in early spring, branches bearing male cones had on average 23% (0.44 g) more dry weight than vegetative branches. on average, 95% o ... | 1990 | 14972965 |
| performance of a canopy light interception model for conifer shoots, trees and stands. | a hierarchical approach was used to evaluate the behavior of a canopy light interception model using submodels for interception at levels of the shoot, crown and stand. mean silhouette areas of individual shoots of lodgepole pine (pinus contorta var. latifolia engelm.) calculated assuming spherical shoot orientation agreed well with silhouette areas measured with a video projection system. a theoretical mean silhouette to total leaf area ratio (star) calculated using measured shoot characteristi ... | 1991 | 14972866 |
| interrelation between shoot characteristics and solar irradiance in the crown of pinus contorta ssp. latifolia. | in pinus contorta doug. ssp. latifolia (engelm.), annual shoot length increment, annual foliage production per shoot, and the daily integral of photosynthetically active radiation (dpar) at shoot tips increased with height in the crown, whereas leaf longevity decreased. there was a decrease in dpar along the shoot from the tip to beyond the oldest leaves, and the value reached at the point just proximal to the oldest leaf cohort was the same for all shoots from all crown locations, regardless of ... | 1991 | 14972867 |
| a simple method for estimating gross carbon budgets for vegetation in forest ecosystems. | gross carbon budgets for vegetation in forest ecosystems are difficult to construct because of problems in scaling flux measurements made on small samples over short periods of time and in determining belowground carbon allocation. recently, empirical relationships have been developed to estimate total belowground carbon allocation from litterfall, and maintenance respiration from tissue nitrogen content. i outline a method for estimating gross carbon budgets using these empirical relationships ... | 1991 | 14972868 |
| importance of the method of leaf area measurement to the interpretation of gas exchange of complex shoots. | net co(2) uptake in full sunlight, total leaf area (tla), projected leaf area of detached leaves (pla), and the silhouette area of attached leaves in their natural orientation to the sun at midday on june 1 (sla) were measured for sun shoots of six conifer species. among species, tla/sla ranged between 5.2 and 10.0 (x bar = 7.3), tla/pla ranged between 2.5 and 2.9 (x bar = 2.7) and pla/sla ranged between 2.0 and 3.7 (x bar = 2.2). these ratios were reflected in the ratios of net photosynthesis c ... | 1991 | 14972884 |
| the chloroplast genome of the gymnosperm pinus contorta: a physical map and a complete collection of overlapping clones. | overlapping restriction fragments of chloroplast dna from the conifer pinus contorta were cloned. out of a total of 49 clones, 33 comprise the minimum set required to represent the entire genome. using the purified inserts of these clones as probes in filter hybridizations, all sites for the three restriction enzymes kpni, hpai and saci in the p. contorta chloroplast genome were mapped. heterologous filter hybridizations and sequence analysis of some of the p. contorta clones were used to determ ... | 1991 | 1682061 |
| duplication of the psba gene in the chloroplast genome of two pinus species. | the psba gene, encoding the d1 protein of photosystem ii, was found to be duplicated in the chloroplast genome of two pine species, pinus contorta and p. banksiana. analysis of cloned overlapping restriction fragments of p. contorta chloroplast dna showed that the two psba genes have the same orientation and are separated by approximately 3.3 kb. the nucleotide sequences of the coding and the upstream regions of the two psba copies were found to be identical, whereas the downstream sequences div ... | 1991 | 1840637 |
| homologues of the green algal gida gene and the liverwort frxc gene are present on the chloroplast genomes of conifers. | strong hybridization signals were obtained from total dna of two conifers, lodgepole pine (pinus contorta) and norway spruce (picea abies), in a southern blot analysis using a probe derived from the chloroplast gida gene of the green alga chlamydomonas reinhardtii. the pine fragments detected by the probe were found to originate from the chloroplast genome and, as judged by the signal intensity, this was also true for the spruce fragments. sequence analysis of the hybridizing pine chloroplast dn ... | 1991 | 1912499 |
| a three-step model for the rearrangement of the chloroplast trnk-psba region of the gymnosperm pinus contorta. | a region of the pinus contorta chloroplast genome which contains a duplication of the psba gene was characterized. from previous experiments it was known that the two copies of the psba gene were located approximately 3.3 kilobase pairs (kbp) apart, that they had the same orientation and that one endpoint of the duplication was 19 base pairs (bp) downstream of the psba stop codon. in order to determine the size and additional genetic content of the duplicated segment, both copies as well as the ... | 1991 | 2057349 |
| a functional promoter shift of a chloroplast gene: a transcriptional fusion between a novel psba gene copy and the trnk (uuu) gene in pinus contorta. | a comparative transcription analysis of the chloroplast trnk-psba-trnh region of the two pine species pinus contorta and pinus sylvestris is reported. the chloroplast genome of p. contorta has previously been shown to contain a duplicated psba gene copy integrated closely upstream of the split trnk gene. this rearrangement has resulted in the gene order psbai-trnk-psbaii-trnh, where psbaii is the ancestral psba gene copy. in p. sylvestris, a species which lacks the psba duplication, transcriptio ... | 1992 | 1302639 |
| antigenic cross-reactivity among monoterpene cyclases from grand fir and induction of these enzymes upon stem wounding. | a major wound response in grand fir (abies grandis) sapling stems is the rapid increase in monoterpene production at the site of injury. monoterpene cyclases (synthases) catalyze the formation of monoterpenes from geranyl pyrophosphate, and total cyclase activity increases markedly on wounding. at least six distinct cyclases, producing different monoterpene products, have been isolated from wounded grand fir saplings and characterized. the predominant wound-inducible cyclase produces both alpha- ... | 1992 | 1567222 |
| root growth and water use efficiency of douglas-fir (pseudotsuga menziesii (mirb.) franco) and lodgepole pine (pinus contorta dougl.) seedlings. | one-year-old douglas-fir (pseudotsuga menziesii (mirb.) franco) and lodgepole pine (pinus contorta dougl.) seedlings were grown for 17 weeks in 100-cm deep, 7.8-liter containers. two douglas-fir provenances, one from a wet and one from a dry site in coastal british columbia, and two lodgepole pine provenances, one from a wet and one from a dry site in interior british columbia, were grown in wet (522% water content) or dry (318% water content) peat/vermiculite soil in a factorial design. each co ... | 1992 | 14969945 |
| the effects of sulphur gas and elemental sulphur dust deposition on pinus contorta x pinus banksiana: cell walls and water relations. | the bulk modulus of elasticity (e) for pinus contorta (lodgepole pine) x pinus banksiana (jack pine) hybrids was compared between a site (ai) close to a sour gas processing plant and a control site (av). the mean bulk modulus of elasticity for branches from ai was 47.5 mpa vs 18.5 mpa for the control site (av). site ai had been exposed to s-gas emissions and large amounts of elemental s deposition and had an acidic soil (ph 4.0 at 10 cm depth). during 1981 the needles at ai had more aluminum and ... | 1992 | 15092007 |
| inheritance of mitochondrial dna in the conifer larix. | restriction fragment length polymorphisms between larix leptolepis and larix decidua were identified in heterologous hybridization experiments, using wheat mitochondrial dna probes specific for atp9, coxi, nad3/rps12, and orf25. analysis of eight individuals of each reciprocal hybrid of these two species revealed that mitochondrial dna was maternally inherited. furthermore, sequences homologous to wheat orf25 were also identified in larix gmelini, larix siberica, larix olgensis, and larix larici ... | 1993 | 24193487 |
| cold acclimation of pinus contorta and pinus sylvestris assessed by chlorophyll fluorescence. | needle samples of six provenances each of lodgepole pine (pinus contorta dougl. var. latifolia) and scots pine (pinus sylvestris l.), originating from latitudes 55 to 68 degrees n in western canada and northern sweden, were collected during the autumn and subjected to freezing temperatures in the range of -8 to -29 degrees c on three occasions in september and october. needle injury was assessed by two different methods: visual assessment and chlorophyll a fluorescence. chlorophyll a fluorescenc ... | 1993 | 14969904 |
| effect of photon flux density on carbon assimilation and chlorophyll a fluorescence of cold-stored white spruce and lodgepole pine seedlings. | white spruce (picea glauca (moench.) voss) and lodgepole pine (pinus contorta dougl. var. latifolia engelm.) seedlings previously held in dark, frozen storage (-2 degrees c) for 2.5 or 6 months, and nursery-grown white spruce seedlings lifted in summer were exposed to photon flux densities (pfds) similar to those that might be encountered at planting. photosynthetic gas exchange and chlorophyll a (chl a) fluorescence were examined in cold-stored and summer-lifted seedlings before and after a 9 h ... | 1993 | 14969928 |
| biosynthesis of monoterpenes: regio- and stereochemistry of (+)-3-carene biosynthesis. | incubation of [1-3h1]geraniol with stem disks of douglas fir (pseudotsuga menziesii) and incubation of [1-3h1]geranyl pyrophosphate with both a soluble enzyme extract from douglas fir and a partially purified preparation of (+)-3-carene synthase from lodgepole pine (pinus contorta) resulted in the production of (+)-3-[3h] carene. subsequent conversion of the product to car-3-en-5-one and to 4-isocaranone followed by base-catalyzed exchange of the alpha-hydrogens established that the 3h located a ... | 1993 | 8373196 |
| diterpenoid resin acid biosynthesis in conifers: characterization of two cytochrome p450-dependent monooxygenases and an aldehyde dehydrogenase involved in abietic acid biosynthesis. | abietic acid is a major component of the rosin fraction of oleoresin synthesized by grand fir (abies grandis), lodgepole pine (pinus contorta), and many other conifer species as a defensive secretion against insect and pathogen attack. the diterpenoid resin acid is derived from geranylgeranyl pyrophosphate via abietadiene, with subsequent oxidation of the c18-methyl of this olefin to abietadienol, abietadienal, and abietic acid. the pathway was confirmed by administering [1,2-14c]acetic acid to ... | 1994 | 8311462 |
| monoterpene synthases of pinus contorta and related conifers. a new class of terpenoid cyclase. | a cell-free extract from the xylem of lodgepole pine (pinus contorta) catalyzes the conversion of [1-3h1]geranyl pyrophosphate to a variety of monoterpene olefins found in lodgepole pine oleoresin. this monoterpene synthase activity is similar to previously described terpenoid cyclases from grand fir (abies grandis) and other higher plants in molecular mass (67 +/- 2 kda as estimated by size-exclusion chromatography), km for geranyl pyrophosphate (7.8 +/- 1.9 microm), and isoelectric point (4.75 ... | 1994 | 8307957 |
| a genomic clone of a type i cab gene encoding a light harvesting chlorophyll a/b binding protein of photosystem ii identified from lodgepole pine. | a type i cab gene encoding chlorophyll a and b binding protein from lodgepole pine (pinus contorta dougl., var. latifolia (engelm.)) has been isolated and sequenced. the gene encodes a proposed 40 amino acid transit peptide and a 234 amino acid mature cab polypeptide. there is no evidence of an intron and examination of the type-specific amino acids confirm this to be a photosystem ii type i cab gene. the coding region is highly conserved with a similar gene from scots pine, the homology extendi ... | 1994 | 8181737 |
| diterpenoid resin acid biosynthesis in conifers: enzymatic cyclization of geranylgeranyl pyrophosphate to abietadiene, the precursor of abietic acid. | abietic acid is a major component of the rosin fraction of oleoresin synthesized by conifer species, such as grand fir (abies grandis) and lodgepole pine (pinus contorta), as a defensive secretion against insect and pathogen attack. this diterpenoid resin acid is derived from geranylgeranyl pyrophosphate by conversion to abietadiene and sequential oxidation of the c18-methyl group of the precursor olefin to a carboxyl function. resin acid biosynthesis is constitutively expressed at high levels i ... | 1994 | 8053674 |
| paternally inherited chloroplast polymorphism in pinus: estimation of diversity and population subdivision, and tests of disequilibrium with a maternally inherited mitochondrial polymorphism. | we have surveyed a chloroplast dna restriction fragment length polymorphism in 745 individuals, distributed rangewide in eight allopatric natural populations of jack pine (pinus banksiana lamb.) and eight allopatric natural populations of lodgepole pine (pinus contorta dougl.). the polymorphic region of the chloroplast genome is located near duplicated psba genes. fourteen length variants were found in the survey, and these variants distinguished the two species qualitatively. variant diversitie ... | 1994 | 8005423 |
| identification and expression of the chloroplast clpp gene in the conifer pinus contorta. | the clpp gene from the conifer pinus contorta was identified and isolated from a chloroplast genomic library by heterologous hybridisation to the second exon of the chloroplast clpp gene in tobacco. dna sequencing of two overlapping clones revealed an uninterrupted 615 bp open-reading frame with 41 to 65% similarity to the clpp genes in five other chloroplast genomes and escherichia coli. the 615 bp sequence in p. contorta contained perfectly matched motifs for the serine and histidine active si ... | 1994 | 7999999 |
| influence of tree size on shoot structure and physiology of pinus contorta and pinus aristata. | this study examined the morphological and physiological characteristics of shoots of large and small mature trees of two pine species with different growth patterns and tree longevities: rocky mountain bristlecone pine (pinus aristata bailey) and lodgepole pine (pinus contorta dougl. ssp. latifolia bailey). large trees of p. aristata had 21% less annual shoot growth but retained more total foliar biomass per shoot than small trees because of a 95% longer leaf life span. large trees of p. contort ... | 1994 | 14967670 |
| distribution and retranslocation of (15)n lodgepole pine over eight growing seasons. | we studied the distribution and retranslocation of n in 11-year-old pinus contorta dougl. trees following a winter application of n at 100 kg ha(-1) as (15)n-urea, (15)nh(4)no(3) or nh(4) (15)no(3). in all treatments, there was little uptake of (15)n after the first growing season although labeled n was still present in the soil. in subsequent years, (15)n in the trees was partly retranslocated, and, at the same time, it was diluted by uptake of unlabeled n from the soil. between years 1 and 8 a ... | 1994 | 14967694 |
| a beta-glucosidase from lodgepole pine xylem specific for the lignin precursor coniferin. | coniferin, the glucoside of the monolignol coniferyl alcohol, accumulates to high levels in gymnosperms during spring-cambial reactivation. a cinnamyl alcohol glucoside/beta-glucosidase system is thought to play a key role in lignification by releasing the monolignol aglycones. investigation of such an enzyme system in the xylem of pinus contorta var latifolia engelm. revealed two major beta-glucosidases. one efficiently hydrolyzed the native substrate, coniferin, and the other was more active a ... | 1995 | 7724669 |
| polymorphic simple sequence repeat regions in chloroplast genomes: applications to the population genetics of pines. | simple sequence repeats (ssrs), consisting of tandemly repeated multiple copies of mono-, di-, tri-, or tetranucleotide motifs, are ubiquitous in eukaryotic genomes and are frequently used as genetic markers, taking advantage of their length polymorphism. we have examined the polymorphism of such sequences in the chloroplast genomes of plants, by using a pcr-based assay. genbank searches identified the presence of several (da)n.(dt)n mononucleotide stretches in chloroplast genomes. a chloroplast ... | 1995 | 7644491 |
| monoterpene synthases from gymnosperms and angiosperms: stereospecificity and inactivation by cysteinyl- and arginyl-directed modifying reagents. | to further define specific structural and mechanistic differences among monoterpene synthases from divergent plant sources, the stereospecificity of the enzyme-catalyzed isomerization of geranyl pyrophosphate to linalyl pyrophosphate and the subsequent cyclization to monoterpene olefins (which have been well established for monoterpene synthases from herbaceous angiosperms) were examined for monoterpene synthases from a conifer, lodgepole pine (pinus contorta). the chiral monoterpenes isolated f ... | 1995 | 7625832 |
| carrier herbal medicine: an evaluation of the antimicrobial and anticancer activity in some frequently used remedies. | the antimicrobial properties of some traditional carrier herbal preparations were evaluated using an agar dilution method. pitch preparations were screened against known human pathogens: escherichia coli, staphylococcus aureus, pseudomonas aeruginosa, candida albicans and aspergillus fumigatus. the results indicated definite antimicrobial activity in the pitch preparations of picea glauca and pinus contorta and provide a starting point for pharmacognostic evaluation of these species. in addition ... | 1996 | 8771456 |
| to live fast or not: growth, vigor and longevity of old-growth ponderosa pine and lodgepole pine trees. | old trees of ponderosa pine (pinus ponderosa dougl. ex laws.) and lodgepole pine (pinus contorta var. latifolia engelm.) were studied to determine volume growth patterns in relation to leaf area. ponderosa pine trees varied in age from 166 to 432 years and were about 77 cm in diameter; lodgepole pine trees varied in age from 250 to 296 years and were about 31 cm in diameter. with the exception of several ponderosa pine trees less than 200 years old, trees of both species had flattened tops, heav ... | 1996 | 14871757 |
| declining forest productivity in aging forest stands: a modeling analysis of alternative hypotheses. | several explanations have been advanced to account for the decline in forest net primary productivity (npp) with age in closed-canopy stands including the hypotheses that: (1) sapwood maintenance respiration rate increases, reducing the availability of carbon to support new growth; (2) stomatal conductance and hence photosynthetic efficiency decline; and (3) soil nutrient availability declines. to evaluate these hypotheses we applied the ecosystem model g'day to a 40- and a 245-year-old stand of ... | 1996 | 14871763 |
| a comparison of isozyme and quantitative genetic variation in pinus contorta ssp. latifolia by fst. | we employed f-statistics to analyze quantitative and isozyme variation among five populations of pinus contorta ssp. latifolia, a wind-pollinated outcrossing conifer with wide and continuous distribution in west north america. estimates of population differentiation (fst) for six quantitative traits were compared with the overall estimate of the differentiation (f*st) from 19 isozymes that tested neutral to examine whether similar evolutionary processes were involved in morphological and isozyme ... | 1996 | 8849910 |
| carrier herbal medicine: traditional and contemporary plant use. | the carrier, an athapaskan-speaking people of northcentral british columbia, occupy the sub-boreal spruce forests of the central interior. this report, which is based on field study, documents some traditional and contemporary knowledge of the medicinal use of plants by the carrier people. important medicinal plants include: abies lasiocarpa, alnus incana, arctostaphylos uva-ursi, artemisia frigida, fragaria virginiana, juniperus communis, picea glauca, pinus contorta, populus tremuloides, rubus ... | 1996 | 8735452 |
| the unusual occurrence of 14-methylhexadecanoic acid in pinaceae seed oils among plants. | 14-methylhexadecanoic (14-mhd) acid has been identified in a sample of pine seed oil (pinus contorta) by gas-liquid chromatography-mass spectrometry of its picolinyl ester derivative. its identification (through its equivalent chain length) and its distribution in four conifer families have been checked. it occurred only in pinaceae, where it was found in 72 species belonging to the genera pinus, abies, cedrus, tsuga, pseudotsuga, larix, and picea, in the range 0.02-1.15%. 14-mhd acid could not ... | 1997 | 9307939 |
| influence of stand structure on carbon-13 of vegetation, soils, and canopy air within deciduous and evergreen forests in utah, united states. | carbon isotope ratios (δ(13)c) were studied in evergreen and deciduous forest ecosystems in semi-arid utah (pinus contorta, populus tremuloides, acer negundo and acer grandidentatum). measurements were taken in four to five stands of each forest ecosystem differing in overstory leaf area index (lai) during two consecutive growing seasons. the δ(13)cleaf (and carbon isotope discrimination) of understory vegetation in the evergreen stands (lai 1.5-2.2) did not differ among canopies with increasing ... | 1997 | 28307459 |
| molecular evolution of cdc2 pseudogenes in spruce (picea). | the p34cdc2 protein and other cyclin-dependent protein kinases (cdk) are important regulators of eukaryotic cell cycle progression. we have previously cloned a functional cdc2 gene from picea abies and found it to be part of a family of related sequences, largely consisting of pseudogenes. we now report on the isolation of partial cdc2 pseudogenes from picea engelmannii and picea sitchensis, as well as partial functional cdc2 sequences from p. engelmannii, p. sitchensis and pinus contorta. a hig ... | 1998 | 9526509 |
| abortifacient effects of lodgepole pine (pinus contorta) and common juniper (juniperus communis) on cattle. | lodgepole pine (pinus contorta) and common juniper (juniperus communis) contain high levels of isocupressic acid that has been identified as the abortifacient component of ponderosa pine needles in cattle. therefore, the abortifacient potential of p contorta and j communis needles was tested in feeding trials with pregnant cattle. cows (2 groups of 2 each) were fed by gavage 4.5-5.5 kg/d ground dry needles from either p contorta or j communis starting on gestation day 250. isocupressic acid (ica ... | 1998 | 9778758 |
| 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 |
| 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 |
| interrelationships among light, photosynthesis and nitrogen in the crown of mature pinus contorta ssp. latifolia. | scaling leaf-level measurements to estimate carbon gain of entire leaf crowns or canopies requires an understanding of the distribution of photosynthetic capacity and corresponding light microenvironments within a crown. we have compared changes in the photosynthetic light response and nitrogen (n) content (per unit leaf area) of pinus contorta dougl. ssp. latifolia engelm. (lodgepole pine) leaves in relation to their age and light microenvironment. the vertical gradient in integrated daily phot ... | 1999 | 12651327 |
| genetic variation in postfire aspen seedlings in yellowstone national park | a rare episode of regeneration of aspen (populus tremuloides michx.) by seeds occurred in yellowstone national park (ynp), wyoming, usa, following extensive fires that occurred in 1988. in 1997, we sampled 410 aspen seedlings from 23 local populations distributed widely across ynp to determine how genetic diversity varies with elevation, substrate, plant competition, ungulate browsing, and geographical location. we employed 132 randomly amplified polymorphic dna (rapd) markers based on six prime ... | 1999 | 10620221 |
| cdna cloning and heterologous expression of coniferin beta-glucosidase. | coniferin beta-glucosidase (cbg) catalyzes the hydrolysis of monolignol glucosides to release the cinnamyl alcohols for oxidative polymerization to lignin. utilizing the n-terminal amino acid sequence of the purified enzyme, the corresponding full-length cdna sequence was isolated from a pinus contorta xylem-specific library. the isolated 1909 nucleotide cdna was confirmed to be that of cbg on the basis of its high homology to family 1 glycosyl hydrolases, the sequence identity with the n-termin ... | 1999 | 10412914 |
| ectomycorrhizal specificity patterns in a mixed pinus contorta and picea engelmannii forest in yellowstone national park. | we used molecular genetic methods to test two hypotheses, (i) that host plant specificity among ectomycorrhizal fungi would be common in a closed-canopy, mixed pinus contorta-picea engelmannii forest in yellowstone national park and (ii) that specificity would be more common in the early successional tree species, p. contorta, than in the invader, p. engelmannii. we identified 28 ectomycorrhizal fungal species collected from 27 soil cores. the proportion of p. engelmannii to p. contorta ectomyco ... | 2000 | 11055953 |
| exposure to dust, resin acids, and monoterpenes in softwood lumber mills. | a study to assess exposure to potential respiratory hazards in a large lumber mill processing spruce (picea engelmannii and glauca), pine (pinus contorta), and fir (abies lasiocarpa) used a random sampling strategy to assess exposures for all jobs in the sawmill, planer mills, and yard. personal samples for inhalable particulate were collected to measure exposure to dust and resin acids (abietic acid and pimaric acid). to estimate wood dust exposure, rather than overall dust, the resin acid cont ... | 2000 | 10976682 |
| 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 |
| photosynthesis and carbon allocation of six boreal tree species grown in understory and open conditions. | one-year-old seedlings of abies balsamea (l.) mill, picea glauca (moench) voss, pinus contorta loudon, betula papyrifera marsh., populus tremuloides michx. and populus balsamifera l. were transplanted in the spring, in pots, to the understory of a mixed p. tremuloides-p. balsamifera stand or to an adjacent open site. growth and leaf characteristics were measured and photosynthetic light response curves determined in mid-august. overall, the coniferous seedlings showed less photosynthetic plastic ... | 2001 | 11276418 |
| construction of a framework map in pinus contorta subsp. latifolia using random amplified polymorphic dna markers. | we report on the construction of the first random amplified polymorphic dna (rapd) framework map in pinus contorta subsp. latifolia. genomic dna of haploid megagametophytes from 90 open-pollinated seeds originating from a single tree were amplified with 840 random decamer oligonucleotide primers by the polymerase chain reaction. three-hundred twenty-eight rapd markers with fragment sizes that ranged between 260 and 3080 base pairs were found segregating at 110 random decamer oligonucleotide prim ... | 2001 | 11341723 |
| effects of climatic warming on cold hardiness of some northern woody plants assessed from simulation experiments. | effects of climatic warming on cold hardiness were investigated for some northern woody plants. in the first experiment, seedlings of norway spruce (picea abies [l.] karst.), scots pine (pinus sylvestris l.) and lodgepole pine (pinus contorta dougl. var. latifolia engelm.) were exposed to naturally fluctuating temperatures averaging -6 degrees c (ambient) and 0 degrees c (elevated) for 16 weeks in midwinter before they were thawed and re-saturated with water. in lodgepole pine, needle sugar conc ... | 2001 | 11319017 |
| the influence of a competitor on the geographic mosaic of coevolution between crossbills and lodgepole pine. | the geographic mosaic theory of coevolution posits that the form of selection between interacting species varies across a landscape with coevolution important and active in some locations (i.e., coevolutionary hotspots) but not in others (i.e., coevolutionary coldspots). we tested the hypothesis that the presence of red squirrels (tamiasciurus hudsonicus) affects the occurrence of coevolution between red crossbills (loxia curvirostra complex) and rocky mountain lodgepole pine (pinus contorta ssp ... | 2001 | 11308086 |
| random amplified polymorphic dna diversity of marginal and central populations in pinus contorta subsp. latifolia. | fifteen populations of lodgepole pine (pinus contorta subsp. latifolia) were surveyed for diversity across 52 random amplified polymorphic dnas (rapds). the objective was to compare single-locus and multilocus structures in four marginal, three intermediate, and eight central populations. single-locus estimates indicated average observed and expected heterozygosity to be 0.19 and 0.17, respectively. when these estimates were split into population categories, a clear trend of increasing diversity ... | 2001 | 11269347 |
| two s-adenosylmethionine synthetase-encoding genes differentially expressed during adventitious root development in pinus contorta. | two s-adenosylmethionine synthetase (sams) cdnas, pcsams1 and pcsams2, have been identified in pinus contorta. we found that the two genes are differentially expressed during root development. thus, pcsams1 is preferentially expressed in roots and exhibits a specific expression pattern in the meristem at the onset of adventitious root development, whereas pcsams2 is expressed in roots as well as in shoots and is down-regulated during adventitious root formation. the expression of the two sams ge ... | 2001 | 11488480 |
| ectomycorrhizal fungal associates of pinus contorta in soils associated with a hot spring in norris geyser basin, yellowstone national park, wyoming. | molecular methods and comparisons of fruiting patterns (i.e., presence or absence of fungal fruiting bodies in different soil types) were used to determine ectomycorrhizal (em) associates of pinus contorta in soils associated with a thermal soil classified as ultra-acidic to extremely acidic (ph 2 to 4). em were sampled by obtaining 36 soil cores from six paired plots (three cores each) of both thermal soils and forest soils directly adjacent to the thermal area. fruiting bodies (mushrooms) were ... | 2001 | 11722904 |
| pine weevil (hylobius abietis) antifeedants from lodgepole pine (pinus contorta). | pine weevils (hylobius abietis) fed less on bark of lodgepole pine (pinus contorta) than on bark of scots pine (p. sylvestris). two pine weevil antifeedants, ethyl trans-cinnamate and ethyl 2,3-dibromo-3-phenyl-propanoate, were isolated from bark of lodgepole pine. these two compounds significantly reduced pine weevil feeding in a laboratory bioassay. in field assays, the second compound significantly decreased pine weevil damage on planted seedlings. ethyl 2,3-dibromo-3-phenylpropanoate has not ... | 2001 | 11817079 |
| identification and characterization of rapd markers inferring genetic relationships among pine species. | total genomic dnas were extracted from several populations of pine species and amplified using oligonucleotides of random sequences. polymorphism in random amplified polymorphic dna (rapd) markers was high and sufficient in distinguishing each of the species. genetic relationships among eight pine species (pinus sylvestris, pinus strobus, pinus rigida, pinus resinosa, pinus nigra, pinus contorta, pinus monticola, and pinus banksiana) from different provenances were analyzed. the degree of band s ... | 2002 | 11908668 |
| the discovery of three genetic races of the dwarf mistletoe arceuthobium americanum (viscaceae) provides insight into the evolution of parasitic angiosperms. | a population genetic approach was used to explore the evolutionary biology of the parasitic angiosperm arceuthobium americanum nutt. ex engelm. (viscaceae). arceuthobium americanum infects three principal hosts and has the most extensive geographical range of any north american dwarf mistletoe. based on the lack of apparent morphological and phenological differences between populations of a. americanum, past researchers have found no evidence for recognizing infraspecific taxa. in this study, mo ... | 2002 | 11918778 |
| comparative population structure and genetic diversity of arceuthobium americanum (viscaceae) and its pinus host species: insight into host-parasite evolution in parasitic angiosperms. | in a recent study we revealed that the parasitic angiosperm arceuthobium americanum is comprised of three distinct genetic races, each associated with a different host in regions of allopatry. in order to assess the role of host identity and geographical isolation on race formation in a. americanum, we compared the genetic population structure of this parasite with that of its three principal hosts, pinus banksiana, pinus contorta var. latifolia and pinus contorta var. murrayana. despite the fac ... | 2002 | 11928707 |
| 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 |
| occurrence of ectomycorrhizal fungi on the forefront of retreating lyman glacier (washington, usa) in relation to time since deglaciation. | glacier forefronts provide a unique system for studying primary succession of plants and fungi. we constructed a chronosequence of ectomycorrhizal fungus occurrence on the forefront of lyman glacier in the north cascades mountain range in washington, usa. the plant communities established on non-vegetated substrate as patchily distributed plant individuals and developed towards complex vegetation with a variety of ectomycorrhizal hosts, including salix commutata, s. phylicifolia, abies lasiocarp ... | 2002 | 11968946 |
| measuring the impact of leptoglossus occidentalis (heteroptera: coreidae) on seed production in lodgepole pine using an antibody-based assay. | we measured the impact of leptoglossus occidentalis on seed production in lodgepole pine, pinus contorta variety latifolia engelmann, using an antibody marker developed to detect residual saliva in fed-on seeds. nymphs, adult females, and adult males were caged on cones during early, mid- and late season cone development. individual analysis of 12,887 seeds extracted from 365 cones revealed that 37.3% seeds tested positive for seed bug saliva. the antibody assay was 38 times more effective than ... | 2002 | 12216819 |
| diversifying coevolution between crossbills and black spruce on newfoundland. | coevolution is increasingly recognized as an important process structuring geographic variation in the form of selection for many populations. here we consider the importance of a geographic mosaic of coevolution to patterns of crossbill (loxia) diversity in the northern boreal forests of north america. we examine the relationships between geographic variation in cone morphology, bill morphology, and feeding performance to test the hypothesis that, in the absence of red squirrels (tamiasciurus h ... | 2002 | 12353759 |
| ultrastructure of vascular cambial cell cytokinesis in pine seedlings preserved by cryofixation and substitution. | trees depend on the secondary vascular cambium to produce cells for new xylem and phloem. the fusiform cells of this lateral meristem are long and narrow, presenting special challenges for arranging the mitotic spindle and phragmoplast. fusiform cambial cells of pinus ponderosa and pinus contorta were studied by cryofixation and cryosubstitution which preserved ultrastructure and phases of cytokinesis with a resolution not previously attained. membranous structures including the plasma membrane, ... | 2002 | 12417935 |
| cellular machinery of wood production: differentiation of secondary xylem in pinus contorta var. latifolia. | the objectives of this study were to define cell structure during pine secondary xylem development and to integrate this information with current knowledge of the biochemistry and physiology of secondary cell wall biosynthesis in gymnosperms. lodgepole pine (pinus contorta var. latifolia englem.) cambium and secondary xylem were cryofixed using high pressure freezing and freeze-substitution which allowed excellent preservation of the cell structure of developing secondary xylem and enabled high- ... | 2002 | 12430016 |
| chloroplast phylogeography and evolution of highly polymorphic microsatellites in lodgepole pine ( pinus contorta). | we employed a novel set of six highly polymophic chloroplastic simple sequence repeat (cpssr) loci to investigate the phylogeography of lodgepole pine ( pinus contorta dougl. ex. loud.), and to examine aspects of the evolutionary process operating on these repetitive dna sequences. chloroplast haplotypes of 500 trees, sampled throughout the range of lodgepole pine, were determined. we found a marked association of genetic distance with physical distance within the scale of 0 to 1,000 km, but no ... | 2002 | 12582709 |
| population structure of a lodgepole pine (pinus contorta) and jack pine (p. banksiana) complex as revealed by random amplified polymorphic dna. | we studied the population structure of a lodgepole (pinus contorta dougl.) and jack pine (pinus banksiana lamb.) complex in west central alberta and neighboring areas by assessing random amplified polymorphic dna (rapd) variability in 23 lodgepole pine, 9 jack pine, and 8 putative hybrid populations. of 200 random primers screened, 10 that amplified 39 sharp and reproducible rapds were chosen for the study. none of the 39 rapds were unique to the parental species. rapd diversity ranged from 0.08 ... | 2002 | 12033622 |
| molecular characterization of bacterial diversity in lodgepole pine (pinus contorta) rhizosphere soils from british columbia forest soils differing in disturbance and geographic source. | rhizosphere bacteria from lodgepole pine (pinus contorta) seedlings were characterized from forest soils which differed in disturbance and geographic source. soil disturbance treatments included whole-tree harvesting with and without heavy soil compaction and whole-tree harvesting with complete surface organic matter removal and heavy soil compaction from british columbia (bc) ministry of forests long-term soil productivity installations in three biogeoclimatic subzones in central bc, canada. ba ... | 2002 | 19709294 |
| development of enzyme-linked immunosorbent assays for isocupressic acid and serum metabolites of isocupressic acid. | the consumption of ponderosa pine (pinus ponderosa), lodgepole pine (pinus contorta), common juniper (juniperus communis), and monterey cypress (cupressus macrocarpa) causes abortions in pregnant cattle. recent studies have identified isocupressic acid (1) as the primary abortificient compound in these plants. in vitro and in vivo studies using rumen and blood have shown isocupressic acid (1) is rapidly metabolized to agathic acid (3), dihydroagathic acid (4), and tetrahydroagathic acid (5). rap ... | 2003 | 12744647 |
| effects of litter addition on ectomycorrhizal associates of a lodgepole pine (pinus contorta) stand in yellowstone national park. | increasing soil nutrients through litter manipulation, pollution, or fertilization can adversely affect ectomycorrhizal (em) communities by inhibiting fungal growth. in this study, we used molecular genetic methods to determine the effects of litter addition on the em community of a pinus contorta stand in yellowstone national park that regenerated after a stand-replacing fire. two controls were used; in unmodified control plots nothing was added to the soil, and in perlite plots perlite, a chem ... | 2003 | 12839743 |