germination of seeds from an irradiated forest: implications for waste disposal.jack pine (pinus banksiana lamb.) retain their seeds from year to year, so that in an irradiated forest, each tree receives a specific dose rate but has seeds that have accumulated a range of total doses. the field irradiator-gamma facility in pinawa, manitoba, contains jack pine that have been irradiated longer and at lower dose rates than previously reported. seed germination and germination rate were examined on seeds irradiated on the parent tree for up to 5 years. germination rate was most ...19921376236
environmental and industrial factors relating to flavor tainting of fish in the upper wisconsin river.extracts from large toothed aspen (populous grandidenta michx.) and jack pine (pinus banksiana lamb.) contained many odor compounds found in flavor-tainted walleye from the wisconsin river, including alkylphenols. aspen wood contained 8 ppb of 2-isopropylphenol, and river sediments also contained low ppb levels of many alkylphenols, including 2-isopropylphenol. thiophenol and thiocresol which sporadically cause offensive sulfury taints in wisconsin river fish were also found in river sediment. q ...19902147030
structures resembling nuclear pores at the orifice of nuclear invaginations in developing microspores of pinus banksiana. 19725019138
radiobotanical parameters of pinus banksiana. 19675585877
purification of an acidic coniferin-hydrolysing beta-glucosidase from developing xylem of pinus banksiana.two cytosolic, acidic (pi 3.8) glycoproteins (m(r) 110,000 and 90,000) from lignifying xylem of pinus banksiana were electrophoretically isolated and confirmed by combined gas chromatography-mass spectrometry to be capable of hydrolysing e-coniferin to trans-coniferyl alcohol. these isoenzymes yielded identical n-terminal sequences having negligible homology with documented glucosidases, suggesting that they constitute a novel form of beta-glucosidase.19947765617
pinus banksiana has at least seven expressed alcohol dehydrogenase genes in two linked groups.the alcohol dehydrogenase (adh) gene family is much more complex in pinus banksiana than in angio-sperms, with at least seven expressed genes organized as two tightly linked clusters. intron number and position are highly conserved between p. banksiana and angiosperms. unlike angiosperm adh genes, numerous duplications, as large as 217 bp, were observed within the noncoding regions of p. banksiana adh genes and may be a common feature of conifer genes. a high frequency of duplication over a wide ...19968917537
proteolytic activity in relation to seasonal cambial growth and xylogenesis in pinus banksiana.proteolytic activity in the cambial zone and developing xylem of pinus banksiana lamb. was investigated over an annual cycle of growth and dormancy. highest proteolytic activity was associated with the most active period of primary-wall radial expansion of cambial derivatives, in early spring, before protoplasmic autolysis was initiated in developing earlywood. three ph maxima of proteolytic activity, near ph 3.0, 6.5 and 9.5, were observed at that time. in general, activities measured at ph val ...199910385993
heavy metal accumulation in soil and jack pine (pinus banksiana) needles in sudbury, ontario, canada. 200010754052
vertical gradients in photosynthetic gas exchange characteristics and refixation of respired co(2) within boreal forest canopies.we compared vertical gradients in leaf gas exchange, co(2) concentrations, and refixation of respired co(2) in stands of populus tremuloides michx., pinus banksiana lamb. and picea mariana (mill.) b.s.p. at the northern and southern boundaries of the central canadian boreal forest. midsummer gas exchange rates in populus tremuloides were over twice those of the two conifer species, and pinus banksiana rates were greater than picea mariana rates. gas exchange differences among the species were at ...199714759908
profile: impending recovery of kirtland's warbler: case study in the effectiveness of the endangered species act/ the endangered species act (esa) has received a large amount of criticism in recent years by conservative landowners and others who believe that it has infringed on property rights. it also has been criticized by those who think it has been costly and ineffective in reaching its goal of preventing extinction and recovering species. recent evidence, however, shows that the esa has stabilized or increased the populations of over a third of the listed species. in addition, its chief administrator ...19989419281
jack pine growth and elemental composition are affected by saline tailings the processing of oil sands from alberta's athabasca formation, large quantities of alkaline, saline tailings and associated process-affected waters are produced. these waters may have a negative effect on plants used in reclamation of mined areas in this region of the northern boreal forest. in the present study, we examined the effects of process-affected water on the growth and elemental composition of jack pine (pinus banksiana lamb.) seedlings. seedlings were grown in sand culture, and t ...200211931458
comparative population structure and genetic diversity of arceuthobium americanum (viscaceae) and its pinus host species: insight into host-parasite evolution in parasitic 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 ...200211928707
the effect of salinity on the emergence and seedling growth of picea mariana, picea glauca, and pinus banksiana.mining operations in areas of the boreal forest have caused salinity issues to be a major concern for reclamation. one of the factors determining successful reclamation is the ability of species to self-propagate. the effects of salinity on the seedling emergence and early growth of three boreal forest conifers: picea mariana, picea glauca, and pinus banksiana were determined. seeds were planted in sand moistened with solutions of various concentrations of sodium chloride or sodium sulfate. seed ...200111586777
synthesis and oxidative insolubilization of cell-wall proteins during osmotic stress.the cell walls in the new white roots of jack pine (pinus banksiana lamb.) were observed to constrict around the shrinking protoplast of osmotically stressed roots, and pressure was maintained via an apparent adjustment of cell-wall size and elasticity. these elastic alterations of the cell wall permitted the root cells to maintain full turgor despite the loss of most of the water in the tissue. the constriction of the root cell wall around the dehydrating protoplasts to maintain turgor may refl ...199910384730
electrophoretic analysis of coniferyl alcohol oxidase and related laccases.gradient gel electrophoretic methods enabled a distinction to be made between coniferyl alcohol oxidase (cao) of lignifying cell walls and a pi approximately 9 pine "laccase" recently implicated in lignification (science 1993 260, 672). following treatment of a partially purified protein mixture from developing xylem of pinus strobus with 2-[n-morpholine]ethanesulfonic acid (mes) buffer, isoelectric focusing and sodium dodecyl sulphate-polyacrylamide gel electrophoresis indicated that cao had be ...19947859710
mechanisms for the development of genetically variable mycorrhizal mycelia in the ectomycorrhizal fungus laccaria in vitro study investigated mechanisms for the development of genetically variable mycorrhizal mycelia for laccaria bicolor. seedlings of jack pine (pinus banksiana) grown nonaseptically in an autoclaved soil substrate were given different l. bicolor inoculum treatments. these included (i) a dikaryotic mycelium genotype (d); (ii) d and basidiospores collected from one group of five sporophores (t1); (iii) d and basidiospores collected from 10 sporophores, two from each of five different group ...19957486997
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 ...19873470779
effects of soil temperature on parameters of a coupled photosynthesis-stomatal conductance examine the effects of soil temperature on a coupled photosynthesis-stomatal conductance model, seedlings of trembling aspen (populus tremuloides michx.), jack pine (pinus banksiana lamb.), black spruce (picea mariana (mill.) b.s.p.) and white spruce (picea glauca (moench) voss) were exposed to soil temperatures ranging from 5 to 35 degrees c for 4 months. light and co(2) response curves of foliar gas exchange were measured for model parameterization. the effects of soil temperature on four k ...200212184971
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 ...19948005423
nucleocytoplasmic interaction at the nuclear envelope in post meiotic microspores of pinus banksiana. 19705494320
reduction in turgid water volume in jack pine, white spruce and black spruce in response to drought and paclobutrazol.significant reductions in needle water content were observed in white spruce (picea glauca (moench) voss), black spruce (picea mariana (mill) b.s.p.), and jack pine (pinus banksiana lamb.) seedlings in response to a 10-day drought, although turgor was apparently maintained. when the seedlings were re-watered after the drought, jack pine needles regained their original saturated volume, whereas white spruce and black spruce needles did not. significant drought-induced reductions in turgor-loss vo ...200012651520
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 ...200212033622
how accessible are receptive megastrobili to pollen? the example of jack pine (pinus banksiana).we examined the effects of wind speeds on pollen capture by megastrobili of jack pine (pinus banksiana). we found that, when wind speed increased from 1.3 to 7.5 m/s, the relative capture efficiency (e(r)) did not change significantly (p </= 0.206) and remained below 12%. however, total capture rates increased linearly with wind speed and atmospheric pollen density. because theoretical models of capture efficiency predict the e(r) to increase to ~80% asymptotically, our findings suggest that rec ...200010675308
estimation of leaf area with an integrating sphere.relative absorptance of intact branches measured with an integrating sphere was compared to leaf area estimated by conventional methods (volume displacement and scanning area meter) for three conifer species: picea mariana (mill.) bsp, pinus banksiana (lamb.) and pseudotsuga menziesii (mirb.) franco. a consistent relationship between relative absorptance and surface area emerged for the three species. the ability to predict leaf area from absorptance was further explored by measuring branches of ...199714759830
germination, growth and gas exchange of selected boreal forest seedlings in soil containing oil sands tailings.greenhouse experiments were conducted to determine the effects of soil enriched in fine tailings (ft), produced by the oil sands extraction, on germination, seedling growth and physiology of several plant species of the boreal forest. the germination of seeds was initially delayed by 15% ft in dogwood (cornus stolonifera michx) and jack pine (pinus banksiana lamb) but not in white spruce [picea glauca (moench) voss]. in the second set of experiments we showed that all dogwood seedlings survived ...200015092982
regulation of branch-level gas exchange of boreal trees: roles of shoot water potential and vapor pressure difference.effects of shoot water potential (psi) and leaf-to-atmosphere vapor pressure difference (vpd) on gas exchange of jack pine (pinus banksiana lamb.), black spruce (picea mariana (mill.) b.s.p.), and aspen (populus tremuloides michx.) were investigated at the northern edge of the boreal forest in manitoba, canada. laboratory measurements on cut branches showed that net photosynthesis (a(n)) and mesophyll conductance (g(m)) of jack pine and g(m) of black spruce did not respond to psi until a thresho ...199714759825
controls over monoterpene emissions from boreal forest conifers.we investigated controls over the emission of monoterpenes from two species of boreal forest conifers, black spruce (picea mariana miller (b.s.p.)) and jack pine (pinus banksiana lamb). monoterpenes are important in plants as carbon-based defensive compounds and in the atmosphere as photochemically reactive compounds that affect ozone and carbon monoxide concentrations. we examined ecological theories of plant allocation to defensive compounds in relation to emission rates of monoterpenes from t ...199714759829
variability in leaf-level co(2) and water fluxes in pinus banksiana and picea mariana in saskatchewan.we measured seasonal and canopy-level gas exchange in two stands of jack pine (pinus banksiana lamb.) and one stand of black spruce (picea mariana (mill.) b.s.p.) on relatively clear days from late may until mid-september 1994. field measurements were made with a portable infrared gas analyzer, and laboratory measurements included photosynthetic oxygen evolution and needle chemical composition. seasonally averaged light-saturated assimilation rates in the field were 4.0 micro mol m(-2) s(-1) in ...199714759828
growth and maintenance respiration rates of aspen, black spruce and jack pine stems at northern and southern boreas sites.we measured stem respiration rates during and after the 1994 growing season of three common boreal tree species at sites near the northern and southern boundaries of the closed-canopy boreal forest in central canada. the growth respiration coefficient (r(g); carbon efflux per micro mole of carbon incorporated in structural matter) varied between 0.25 and 0.76, and was greatest for black spruce (picea mariana (mill.) b.s.p.), least for jack pine (pinus banksiana lamb.) and intermediate for trembl ...199714759827
cumulative impact of 40 years of industrial sulfur emissions on a forest soil in west-central alberta (canada).the impact of 40 years of sulfur (s) emissions from a sour gas processing plant in alberta (canada) on soil development, soil s pools, soil acidification, and stand nutrition at a pine (pinus contorta x pinus banksiana) ecosystem was assessed by comparing ecologically analogous areas subjected to different s deposition levels. sulfur isotope ratios showed that most deposited s was derived from the sour gas processing plant. the soil subjected to the highest s deposition contained 25.9 kmol s ha( ...200415276281
seedlings of five boreal tree species differ in acclimation of net photosynthesis to elevated co(2) and temperature.biochemical models of photosynthesis suggest that rising temperatures will increase rates of net carbon dioxide assimilation and enhance plant responses to increasing atmospheric concentrations of co(2). we tested this hypothesis by evaluating acclimation and ontogenetic drift in net photosynthesis in seedlings of five boreal tree species grown at 370 and 580 &mgr;mol mol(-1) co(2) in combination with day/night temperatures of 18/12, 21/15, 24/18, 27/21, and 30/24 degrees c. leaf-area-based rate ...199812651406
a diverse family of phenylalanine ammonia-lyase genes expressed in pine trees and cell cultures.using degenerate pcr primers that target evolutionarily conserved sequences in pal genes, we show that in the gymnosperm, pinus banksiana, phenylalanine ammonia-lyase (pal) is encoded by a multigene family of at least eight to ten loci. five classes of pal sequence were easily distinguished among 28 clones sequenced from the products of pcr amplification of haploid genomic dna. the dominant sequence from each class was named, yielding pal1 to pal5 loci. these genes shared 68.8% to 94.0% nucleoti ...19989620261
parameterization and testing of a coupled photosynthesis-stomatal conductance model for boreal trees.a coupled photosynthesis-stomatal conductance model was parameterized and tested with branches of black spruce (picea mariana (mill.) b.s.p.) and jack pine (pinus banksiana lamb.) trees growing in the northern study area of the boreal ecosystem-atmosphere study (boreas) in manitoba, canada. branch samples containing foliage of all age-classes were harvested from a lowland old black spruce (obs) and an old jack pine (ojp) stand and the responses of photosynthesis (a(n)) and stomatal conductance ( ...199812651384
characterization of radiation regimes in nonrandom forest canopies: theory, measurements, and a simplified modeling approach.we used field measurements and monte carlo simulations of canopy gap-size distribution and gap fraction to examine how beam radiation interacts with clumped boreal forest canopies of aspen (populus tremuloides michx.), black spruce (picea mariana (mill.) b.s.p.) and jack pine (pinus banksiana lamb.). we demonstrate that the beer-lambert law can be modified to accommodate transmission of radiation through a clumped forest canopy as a function of path length or sun zenith angle. multiband vegetati ...199912651308
leaf area dynamics of a boreal black spruce fire chronosequence.specific leaf area (sla) and leaf area index (lai) were estimated using site-specific allometric equations for a boreal black spruce (picea mariana (mill.) bsp) fire chronosequence in northern manitoba, canada. stands ranged from 3 to 131 years in age and had soils that were categorized as well or poorly drained. the goals of the study were to: (i) measure sla for the dominant tree and understory species of boreal black spruce-dominated stands, and examine the effect of various biophysical condi ...200212359526
hydraulic adjustment in jack pine and black spruce seedlings under controlled cycles of dehydration and rehydration.drought adjustments were compared in black spruce (picea mariana[mill] b.s.p), and jack pine (pinus banksiana[lamb.]) by subjecting seedlings to five cycles of dehydration and rehydration. a computer-controlled root misting chamber system, supplied low (-1.5 mpa), moderate (-2.0 mpa), and severe (-2.5 mpa) dehydration, respectively, in cycles 1, 3 and 5. although cell water relations failed to adjust to chronic dehydration, there was limited osmotic adjustment in black spruce (cycle 3), and wate ...200312675743
changes in protein synthesis during drought conditioning in roots of jack pine seedlings (pinus banksiana lamb.).the impact of drought conditioning on the ability of eight-week-old jack pine (pinus banksiana lamb.) seedlings to withstand drought was assessed. two progressive cycles of drought conditioning significantly increased the survival of seedlings subjected to a subsequent prolonged drought. the in vivo accumulation of several root membrane proteins during drought conditioning was correlated with an increase in seedling survival. a group of root proteins, ranging in molecular mass from 43 to 47 kda, ...199414967686
the lichen-forming ascomycete evernia mesomorpha associates with multiple genotypes of trebouxia jamesii.the epiphyte evernia mesomorpha forms a lichen association with green algae in the genus trebouxia. little is known about the population structure of e. mesomorpha. here, population structure of the algal and fungal symbionts was examined for 290 lichen thalli on 29 jack pine (pinus banksiana) trees in manitoba. through phylogenetic analysis of internal transcribed spacer (its) nuclear ribosomal dna (rdna) sequences, five algal genotypes were detected that were nested within t. jamesii. two fung ...200616411936
regulation of early flowering in pinus banksiana.seedlings of three families of jack pine (pinus banksiana lamb.) were subjected to 16 combinations of photoperiod, growth environment (outdoors, greenhouse and biotron) and gibberellin (ga(4/7)) treatment. after 14 months, which included two dormancy induction periods, ovulate flowering was observed. there was a strong positive correlation between flowering and seedling height; female flower production was stimulated by both a declining photoperiod during bud development and ga(4/7) treatment; a ...199414967702
heat-shock response of pinus and picea seedlings.the effect of a short period of elevated temperature, or heat shock, on protein synthesis was investigated in 2-day-old seedlings of jack pine (pinus banksiana lamb.), loblolly pine (p. taeda l.), lodgepole pine (p. contorta dougl.), black spruce (picea mariana (mill.) bsp), and white spruce (p. glauca (moench) voss.). in all species, heat shock led to increased [(35)s]methionine incorporation into heat-shock proteins (hsp's) with molecular masses of 83 and 72 kda. heat shock also induced synthe ...199414967637
identification and characterization of rapd markers inferring genetic relationships among pine 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 ...200211908668
chemical basis for feeding adaptation of pine sawflies neodiprion rugifrons and neodiprion swainei.larvae of two pine sawflies, neodiprion rugifrons midd. and neodiprion swainei midd., consume only old foliage of jack pine, pinus banksiana lamb., and leave juvenile foliage intact early in the growing season. the chemical basis for this unique adaptation is a feeding deterrent chemical, 13-keto-8(14)-podocarpen-18-oic acid, which was isolated from juvenile foliage. the content of this deterrent chemical decreases as the foliage begins to mature until needles become acceptable to neodiprion swa ...197717783252
inequality of size and size increment in pinus banksiana in relation to stand dynamics and annual growth rate.changes in size inequality in tree populations are often attributed to changes in the mode of competition over time. the mode of competition may also fluctuate annually in response to variation in growing conditions. factors causing growth rate to vary can also influence competition processes, and thus influence how size hierarchies develop.200818089583
ion uptake in pinus banksiana treated with sodium chloride and sodium sulphate.within its wide range across canada, jack pine is exposed to salinity from both natural and anthropogenic sources. to compare the effects of cl and so(4) on salt injury, sand and solution-culture grown jack pine (pinus banksiana lamb.) seedlings were treated with nutrient solutions containing 60 or 120 mm nacl, 60 mm na(2)so(4), or a mixture of 60 mm nacl and 30 mm na(2)so(4). after 5 weeks of salt treatments, concentrations of cl, k, na, and so(4) were determined in roots, stem and needles of t ...200415032846
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 ...200211918778
sexual expression in container-grown jack pine seedlings.we assessed the effects of nitrogen, drought and gibberellin a(4/7) on sexual expression of 2- and 3-year-old jack pine (pinus banksiana l.) seedlings grown in either a 1/3 peat/sand mix or a 3/1 peat/perlite mix. the seedlings were either watered daily (well-watered treatment) or droughted by withholding water from july 13 to august 24 (drought treatment). half of the plants in each irrigation treatment were sprayed with 200 mg l(-1)gibberellin a(4/7) at weekly intervals from june 28 to august ...199514965925
effects of soil temperature and elevated atmospheric co2 concentration on gas exchange, in vivo carboxylation and chlorophyll fluorescence in jack pine and white birch jack pine (pinus banksiana lamb.) and current-year white birch (betula papyrifera marsh.) seedlings were grown in ambient (360 ppm) or twice ambient (720 ppm) atmospheric co2 concentration ([co2]) and at three soil temperatures (tsoil = 7, 17 and 27 degrees c initially, increased to 10, 20 and 30 degrees c two months later, respectively) in a greenhouse for 4 months. in situ foliar gas exchange, in vivo carboxylation characteristics and chlorophyll fluorescence were measured after 2 ...200515741153
comparing stem respiration and growth of jack pine provenances from northern and southern locations.stem respiration rates of 31-year-old jack pine (pinus banksiana lamb.) trees from northern and southern provenances growing in a common garden were compared. at 15 degrees c, the seasonal course of stem respiration rate of northern provenances was not statistically different from that of southern provenances. a relationship existed between maintenance respiration rate and stem growth rate. because relationships between sapwood relative growth rate and annual growth and maintenance respiration r ...199614871675
a mitochondrial dna minisatellite reveals the postglacial history of jack pine (pinus banksiana), a broad-range north american conifer.jack pine (pinus banksiana lamb.) is a broadly distributed north american conifer and its current range was covered by the laurentian ice sheet during the last glacial maximum. to infer about the history and postglacial colonization of this boreal species, range-wide genetic variation was assessed using a new and highly variable minisatellite-like marker of the mitochondrial genome. among the 543 trees analysed, 14 distinct haplotypes were detected, which corresponded to different repeat numbers ...200516156818
hydraulic acclimation to shading in boreal conifers of varying shade tolerance.the purpose of this study was to determine how shading affects the hydraulic and wood-anatomical characteristics of four boreal conifers (pinus banksiana, pinus contorta, picea glauca and picea mariana) that differ in shade tolerance. plants were grown in an open field and under a deciduous-dominated overstory for 6 years. sapwood- and leaf-area specific conductivity, vulnerability curves, and anatomical measurements (light and scanning electron microscopy) were made on leading shoots from six t ...201019968826
mycorrhizal inoculum potentials of pure reclamation materials and revegetated tailing sands from the canadian oil sand industry.recent improvements in the management of oil sand tailings used by the canadian oil sand industry have resulted in the production of composite tailing sands (ct): a new challenging material for reclamation work. jack pine (pinus banksiana lamb.), hybrid poplar (populus deltoides bartr. ex marsh. xpopulus nigra l.) and red clover (trifolium pratense l.) plants were used in an 8-week greenhouse bioassay to evaluate the mycorrhizal inoculum potential of ct. this inoculum potential was compared with ...200415883852
increased air temperature during simulated autumn conditions impairs photosynthetic electron transport between photosystem ii and photosystem i.changes in temperature and daylength trigger physiological and seasonal developmental processes that enable evergreen trees of the boreal forest to withstand severe winter conditions. climate change is expected to increase the autumn air temperature in the northern latitudes, while the natural decreasing photoperiod remains unaffected. as shown previously, an increase in autumn air temperature inhibits co2 assimilation, with a concomitant increased capacity for zeaxanthin-independent dissipation ...200818375598
interacting influence of light and size on aboveground biomass distribution in sub-boreal conifer saplings with contrasting shade tolerance.plant size often influences shade tolerance but relatively few studies have considered the functional response of taller plants to contrasting light environments. several boreal and sub-boreal abies, picea and pinus species were studied along a light (0-90% full sunlight) and size (30-400-cm high) gradient to examine the interactive influence of tree size and light availability on aboveground biomass distribution. sampling was conducted in two regions of canada: (a) british columbia, for abies l ...200515631985
bioactive properties of wood knot extracts on cultured human cells.not all felled wood is converted to timber or pulp, with the remaining material being a rich source of relatively unexplored and unexploited potentially novel bioactive compounds. therefore the potential bioactive effects of two softwood knot (the part of the branch encased in the tree stem) extracts--namely, pinus banksiana lamb. (jack pine) and picea sitchensis (bong.) carr. (sitka spruce)--were investigated by (1) determining their effects on the viability and antioxidant status of human jurk ...200920041777
patterns of inter-annual variation in the size asymmetry of growth in pinus banksiana.a large body of literature suggests that asymmetric competition, where large individuals suppress the growth of smaller individuals by intercepting a disproportionate share of incoming light, is a dominant process in tree population development. this has not been examined extensively for long-lived tree species that accumulate growth over many years under varying growing conditions. using dendrochronological techniques, we reconstructed annual growth and mortality rates at ten stands of jack pin ...201020063169
role of aquaporins in root water transport of ectomycorrhizal jack pine (pinus banksiana) seedlings exposed to nacl and fluoride.effects of ectomycorrhizal (ecm) fungus suillus tomentosus on water transport properties were studied in jack pine (pinus banksiana) seedlings. the hydraulic conductivity of root cortical cells (l(pc)) and of the whole root system (l(pr)) in ecm plants was higher by twofold to fourfold compared with the non-ecm seedlings. hgcl2 had a greater inhibitory effect on l(pc) in ecm compared with non-ecm seedlings, suggesting that the mercury-sensitive, aquaporin (aqp)-mediated water transport was large ...201020040068
accumulation of free amino acids in the shoots and roots of three northern conifers during drought.the effects of drought on the free amino acid pools in 21- to 23-week-old seedlings of black spruce (picea mariana (mill.) britt.), white spruce (picea glauca (moench.) voss) and jack pine (pinus banksiana lamb.) were followed during soil drying. although water and pressure potentials were sensitive to water deficits, large changes in osmotic potential were not recorded until after the development of severe drought. total soluble amino nitrogen in the shoots and roots of the three species rose a ...199014972940
acquired thermotolerance of jack pine, white spruce and black spruce seedlings.the acquired thermotolerance of first-year seedlings of jack pine (pinus banksiana lamb.) hardened at 36, 38, 40 or 42 degrees c for 90, 180 or 360 minutes and of black spruce (picea mariana (mill.) b.s.p.) hardened at 34, 36, 38 or 40 degrees c for 30, 90, 180 or 360 minutes was determined by comparison of needle damage to that of non-hardened seedlings (25 degrees c) following exposure to temperatures of 49 and 47.5 degrees c, respectively. compared to seedlings kept at 25 degrees c, heat inju ...199114972899
carbohydrate relations during propagation of cuttings from sexually mature pinus banksiana trees.concentrations of glucose, sucrose, soluble reducing sugars, starch and total non-structural carbohydrate were determined during propagation of cuttings from sexually mature pinus banksiana lamb. trees. such cuttings rarely initiate adventitious roots whatever the method or duration of propagation. terminals, needles, and upper and basal stem segments of cuttings were analyzed at day 0 and every 2 days for 18 days. comparison of the results with those of earlier studies with cuttings of p. banks ...198914972977
temporal variation of the mating system in a natural population of jack pine.mating system parameters of a northern conifer, pinus banksiana lamb., were estimated from allozyme polymorphisms. seeds analyzed were obtained from serotinous cones of 30 individuals and represented four independent fertilizations in 1975, 1976, 1977 and 1978. results indicated that a mixed mating system model, with a mean effective outcrossing rate of 88 +/- 0.047%, described the mating system of this stand. however, there was an approximately linear increase in the apparent selfing rate from ...198517246256
ectomycorrhizal fungi affect the physiological responses of picea glauca and pinus banksiana seedlings exposed to an nacl gradient.we tested the effects of ectomycorrhizal (ecm) inoculation on greenhouse-grown white spruce (picea glauca (moench) voss) and jack pine (pinus banksiana l.) seedlings to be used for revegetation of salt-affected tailing sands resulting from the exploitation of oil sand in northeastern alberta, canada. white spruce and jack pine seedlings were inoculated with three ecm fungi selected for their in vitro tolerance to excess na+ and cl-: hebeloma crustuliniforme (bull) quel. uamh 5247, laccaria bicol ...200616740494
cree antidiabetic plant extracts display mechanism-based inactivation of cyp3a4.seventeen cree antidiabetic medicinal plants were studied to determine their potential to inhibit cytochrome p450 3a4 (cyp3a4) through mechanism-based inactivation (mbi). the ethanolic extracts of the medicinal plants were studied for their inhibition of cyp3a4 using the substrates testosterone and dibenzylfluorescein (dbf) in high pressure liquid chromatography (hplc) and microtiter fluorometric assays, respectively. using testosterone as a substrate, extracts of alnus incana, sarracenia purpur ...201121186373
effects of canopy-deposition interaction on h+ supply to soils in pinus banksiana and populus tremuloides ecosystems in the athabasca oil sands region in alberta, canada.soil acidification has been of concern in the oil sands region in alberta due to increased acid deposition. using the canopy budget model, and accounting for h(+) canopy leaching by organic acids, we determined sources and sinks of h+ in throughfall in jack pine (pinus banksiana) and trembling aspen (populus tremuloides) stands in two watersheds from 2006 to 2009. in pine stands, h+ deposition was greater in throughfall than in bulk precipitation while the opposite was true in aspen stands. the ...201121310518
evaluation of a new battery of toxicity tests for boreal forest soils: assessment of the impact of hydrocarbons and salts.the ability to assess the toxic potential of soil contamination within boreal regions is currently limited to test species representative of arable lands. this study evaluated the use of six boreal plant (pinus banksiana, picea glauca, picea mariana, populus tremuloides, calamagrostis canadensis, and solidago canadensis) and four invertebrate (dendrodrilus rubidus, folsomia nivalis, proisotoma minuta, and oppia nitens) species, and compared their performance to a suite of standard agronomic soil ...201222228553
Effect of water stress and fungal inoculation on monoterpene emission from an historical and a new pine host of the mountain pine beetle.The mountain pine beetle (Dendroctonus ponderosae, MPB) has killed millions of lodgepole pine (Pinus contorta) trees in Western Canada, and recent range expansion has resulted in attack of jack pine (Pinus banksiana) in Alberta. Establishment of MPB in the Boreal forest will require use of jack pine under a suite of environmental conditions different from those it typically encounters in its native range. Lodgepole and jack pine seedlings were grown under controlled environment conditions and su ...201121874397
acclimation of respiratory temperature responses in northern and southern populations of pinus banksiana.temperature acclimation of respiration may contribute to climatic adaptation and thus differ among populations from contrasting climates. short-term temperature responses of foliar dark respiration were measured in 33-yr-old trees of jack pine (pinus banksiana) in eight populations of wide-ranging origin (44-55 degrees n) grown in a common garden at 46.7 degrees n. it was tested whether seasonal adjustments in respiration and population differences in this regard resulted from changes in base re ...200918811616
gas exchange and growth responses of ectomycorrhizal picea mariana, picea glauca, and pinus banksiana seedlings to nacl and spruce (picea mariana), white spruce (picea glauca), and jack pine (pinus banksiana) seedlings were inoculated with hebeloma crustuliniforme or laccaria bicolor and subjected to nacl and na (2)so (4) treatments. the effects of ectomycorrhizas on salt uptake, growth, gas exchange, and needle necrosis varied depending on the tree and fungal species. in jack pine seedlings, ectomycorrhizal (ecm) fungi reduced shoot and root dry weights and in the ecm white spruce, there was a small increase i ...200616755463
purification and properties of glutamine synthetase in leaves and roots of pinus banksiana lamb.a method is described for the purification of glutamine synthetase (gs; ec. from the leaves and roots of pinus banksiana lamb., a conifer which utilizes ammonium as its primary nitrogen source. the enzyme was purified to apparent homogeneity by a procedure involving salt fractionation as well as ion-exchange, size exclusion, and affinity chromatography. since the final preparation produced two bands on sds polyacryamide gels but only one band on a nondenaturating gel, it is concluded th ...199016667762
relationships among drought resistance, transpiration rates, and abscisic acid levels in three northern conifers.water potentials, transpiration rates and abscisic acid (aba) levels in shoots of black spruce (picea mariana (mill.) bsp), white spruce (picea glauca (moench) voss) and jack pine (pinus banksiana lamb.) seedlings were monitored during periods of drought and recovery from drought. abscisic acid contents of shoots increased during the period of drought as water potentials decreased. the increase in levels of aba was closely associated with a decrease in rates of transpiration. in the spruces, the ...198614975892
stable isotopes, ecological integration and environmental change: wolves record atmospheric carbon isotope trend better than tree rings.large-scale patterns of isotope ratios are detectable in the tissues of organisms, but the variability in these patterns often obscures detection of environmental trends. we show that plants and animals at lower trophic levels are relatively poor indicators of the temporal trend in atmospheric carbon isotope ratios (delta13c) when compared with animals at higher trophic levels. first, we tested how differences in atmospheric delta13c values were transferred across three trophic levels. second, w ...200717686730
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 ...199215092007
fungal elicitor-mediated responses in pine cell cultures : iii. purification and characterization of phenylalanine ammonia-lyase.phenylalanine ammonia-lyase (pal, ec is involved in the lignification of pine suspension cultures in response to an elicitor prepared from an ectomycorrhizal fungus. to elucidate the molecular basis of this response, pal was purified to homogeneity from jack pine (pinus banksiana) suspension cultures using anion-exchange and chromatofocussing fast protein liquid chromatography. physical characterization of the enzyme revealed that pine pal was similar to pal from other plant sources. pi ...199216668649
the activity, characterization and distribution of the nitrogen assimilation enzyme, glutamine synthetase, in jack pine seedlings.the extraction of glutamine synthetase (gs) from jack pine (pinus banksiana lamb.) tissue was facilitated by solubilization of the tissue with 1% or more nonidet p-40 detergent. in contrast with procedures commonly used to extract gs from other plant tissues, highest recovery of gs was obtained when jack pine tissues were subjected to ultrasonic homogenization in the absence of pvp. chromatography on deae-sephacel showed that jack pine needles possess two isoforms of gs. isoform gs(1), which is ...198814972821
planting stress in newly planted jack pine and white spruce. 1. factors influencing water uptake.bareroot jack pine (pinus banksiana lamb.) seedlings (2 + 0) and bareroot white spruce (picea glauca (moench) voss) transplants (1 1/2 + 1 1/2) were taken from cold storage and planted on a clearcut forest site in northeastern ontario on several dates between may 6 and june 5 during which period soil temperature at 15 cm depth increased from 0 to 18 degrees c. additional cold-stored trees were transferred to a greenhouse where they were grown in pots for 0, 7 or 28 days and then placed with thei ...198814972837
planting stress in newly planted jack pine and white spruce. 2. changes in tissue water potential components.water relations of bare-root jack pine (pinus banksiana lamb.) and white spruce (picea glauca (moench) voss) planted in a greenhouse and on a boreal cut-over site were examined during the first growing season. in field-planted trees, maximum stomatal conductances (g(wv)) were initially low (< 0.10 cm s(-1)). base and minimum xylem pressure potentials (psi(x(base)) and psi(x(min))) were less than -1.5 and -1.7 mpa for jack pine and -2.0 and -2.6 mpa for white spruce, respectively. during the grow ...198814972838
genetic variability of canadian populations of the sapstain fungus ophiostoma piceae.abstract genetic diversity was studied in seven canadian populations of ophiostoma piceae, the most prevalent sapstain fungus in canadian softwoods. a total of 239 single-spore isolates were recovered following a systematic survey of sapstain fungi in logs and lumber at seven selected sawmills in six canadian provinces (british columbia, alberta, saskatchewan, ontario, québec, and new brunswick). sampling was carried out on five commercially important softwood species: balsam fir (abies balsamea ...200118943849
effects of nacl on responses of ectomycorrhizal black spruce (picea mariana), white spruce (picea glauca) and jack pine (pinus banksiana) to spruce (picea mariana), white spruce (picea glauca) and jack pine (pinus banksiana) were inoculated with suillus tomentosus and subjected to potassium fluoride (1 mm kf and 5 mm kf) in the presence and absence of 60 mm nacl. the nacl and kf treatments reduced total dry weights in jack pine and black spruce seedlings, but they did not affect total dry weights in white spruce seedlings. the addition of 60 mm nacl to kf treatment solutions alleviated fluoride-induced needle injury in ectomyco ...200919121099
absorption and assimilation of nitrate and ammonium ions by jack pine seedlings.jack pine (pinus banksiana lamb.) seedlings were grown in a shaded or unshaded light regime with either no(3) (-)- or nh(4) (+)-n as the sole n source. after three months, seedlings grown with nh(4) (+)-n were larger than seedlings grown with no(3) (-)-n. irradiance had a greater effect on growth of ammonium-fed seedlings than on growth of nitrate-fed all times from 6 to 24 h following incorporation of (15)n, soluble, insoluble, and total (15)n contents of shoots and roots were high ...199214969960
formation of ligno-suberized tissues in jack pine resistant to the european race of gremmeniella abietina.abstract a histological study was conducted to provide insights into the defense mechanisms of pinus banksiana resistant to the european (eu) race of gremmeniella abietina in naturally infected sites. at the time of sampling, the only apparent symptom was a blight induced at the tip of the shoots. the identity of g. abietina during microscopic examinations was confirmed by an immunogold labeling method. once the fungus had succeeded in penetrating the bracts through stomata, it invaded the stem ...200118943327
relative susceptibility of four pine species to infection by pinewood nematode.mature trees of eastern white, jack, scotch, and shortleaf pines were inoculated with 25,000-34,000 pinewood nematodes, bursaphelenchus xylophilus, isolated from infected scotch pines in missouri. equal numbers of trees of each species inoculated with distilled water served as controls. nine of fifteen scotch pines died within 4 months of nematode infection or during the winter and early spring following infection. a single eastern white and shortleaf pine died. no jack pines died. a single scot ...198719290105
changes in soil carbon and nitrogen cycling along a 72-year wildfire chronosequence in michigan jack pine forests.we investigated the changes in soil processes following wildfire in michigan jack pine (pinus banksiana) forests using a chronosequence of 11 wildfire-regenerated stands spanning 72 years. the objective of this study was to characterize patterns of soil nutrients, soil respiration and n mineralization with stand development, as well as to determine the mechanisms driving those patterns. we measured in situ n mineralization and soil respiration monthly during the 2002 growing season and used mult ...200616804702
the co-occurrence of ectomycorrhizal, arbuscular mycorrhizal, and dark septate fungi in seedlings of four members of the pinaceae.although roots of species in the pinaceae are usually colonized by ectomycorrhizal (em) fungi, there are increasing reports of the presence of arbuscular mycorrhizal (am) and dark septate endophytic (dse) fungi in these species. the objective of this study was to determine the colonization patterns in seedlings of three pinus (pine) species (pinus banksiana, pinus strobus, pinus contorta) and picea glauca x picea engelmannii (hybrid spruce) grown in soil collected from a disturbed forest site. s ...200818157555
transcriptome resources and functional characterization of monoterpene synthases for two host species of the mountain pine beetle, lodgepole pine (pinus contorta) and jack pine (pinus banksiana).the mountain pine beetle (mpb, dendroctonus ponderosae) epidemic has affected lodgepole pine (pinus contorta) across an area of more than 18 million hectares of pine forests in western canada, and is a threat to the boreal jack pine (pinus banksiana) forest. defence of pines against mpb and associated fungal pathogens, as well as other pests, involves oleoresin monoterpenes, which are biosynthesized by families of terpene synthases (tpss). volatile monoterpenes also serve as host recognition cue ...201323679205
increased air temperature during simulated autumn conditions does not increase photosynthetic carbon gain but affects the dissipation of excess energy in seedlings of the evergreen conifer jack pine.temperature and daylength act as environmental signals that determine the length of the growing season in boreal evergreen conifers. climate change might affect the seasonal development of these trees, as they will experience naturally decreasing daylength during autumn, while at the same time warmer air temperature will maintain photosynthesis and respiration. we characterized the down-regulation of photosynthetic gas exchange and the mechanisms involved in the dissipation of energy in jack pin ...200717259287
effect of natural root grafting on growth response of jack pine (pinus banksiana; pinaceae).• premise of study: trees are traditionally considered as distinct entities even though they can share a communal root system through root grafts, which are morphological unions between two or more roots. little is known regarding the ecological significance of natural root grafting, but because grafted trees can share resources and secondary compounds, growth of linked trees can be affected directly by the presence of root grafts. traditional forest ecology concepts may have to be revised to in ...201121653509
variation in complex semiochemical signals arising from insects and host plants.chemical communication by many insect species involves complex signals of both insect and plant origin. much attention has been focused on the behavioral activities of these components but less on their sources of variation, despite implications for evolutionary theory and pest management. we studied variation in chemical signaling at host, tree-within-host, and beetle-on-tree scales using tunneling male pine engravers [ips pini (say)] on jack, pinus banksiana lamb, red, p. resinosa aiton, and w ...201020550801
plant canopy gap-size analysis theory for improving optical measurements of leaf-area index.optical instruments currently available for measuring the leaf-area index (lai) of a plant canopy all utilize only the canopy gap-fraction information. these instruments include the li-cor lai-2000 plant canopy analyzer, decagon, and demon. the advantages of utilizing both the canopy gap-fraction and gap-size information are shown. for the purpose of measuring the canopy gap size, a prototype sunfleck-lai instrument named tracing radiation and architecture of canopies (trac), has been developed ...199521060464
untangling positive and negative biotic interactions: views from above and below ground in a forest ecological communities, the outcome of plant-plant interactions represents the net effect of positive and negative interactions occurring above and below ground. untangling these complex relationships can provide a better understanding of mechanisms that underlie plant-plant interactions and enhance our ability to predict population, community, and ecosystem effects of biotic interactions. in forested ecosystems, tree seedlings interact with established vegetation, but the mechanisms and outc ...201021302835
biogeographic variation in evergreen conifer needle longevity and impacts on boreal forest carbon cycle projections.leaf life span is an important plant trait associated with interspecific variation in leaf, organismal, and ecosystem processes. we hypothesized that intraspecific variation in gymnosperm needle traits with latitude reflects both selection and acclimation for traits adaptive to the associated temperature and moisture gradient. this hypothesis was supported, because across 127 sites along a 2,160-km gradient in north america individuals of picea glauca, picea mariana, pinus banksiana, and abies b ...201425225397
pathogenicity of bursaphelenchus xylophilus on pines in minnesota and wisconsin.the pinewood nematode, bursaphelenchus xylophilus, was inoculated into established native jack and red pines (pinus banksiana and p. resinosa) and exotic austrian pine (p. nigra) in minnesota and wisconsin forests during summer 1981. the nematode isolates did not kill established nonstressed pine trees growing in the forest. however, the same nematode isolates killed pine seedlings under greenhouse conditions. girdling the main stem of some trees to induce stress resulted in the death of the maj ...198619294138
mountain pine beetles colonizing historical and naive host trees are associated with a bacterial community highly enriched in genes contributing to terpene metabolism.the mountain pine beetle, dendroctonus ponderosae, is a subcortical herbivore native to western north america that can kill healthy conifers by overcoming host tree defenses, which consist largely of high terpene concentrations. the mechanisms by which these beetles contend with toxic compounds are not well understood. here, we explore a component of the hypothesis that beetle-associated bacterial symbionts contribute to the ability of d. ponderosae to overcome tree defenses by assisting with te ...201323542624
inhibition of insect glutathione s-transferase (gst) by conifer extracts.insecticide synergists biochemically inhibit insect metabolic enzyme activity and are used both to increase the effectiveness of insecticides and as a diagnostic tool for resistance mechanisms. considerable attention has been focused on identifying new synergists from phytochemicals with recognized biological activities, specifically enzyme inhibition. jack pine (pinus banksiana lamb.), black spruce (picea mariana (mill.) bsp.), balsam fir (abies balsamea (l.) mill.), and tamarack larch (larix l ...201425270601
phylogeographic structure of jack pine (pinus banksiana; pinaceae) supports the existence of a coastal glacial refugium in northeastern north america.• premise of the study: the genetic structure of jack pine (pinus banksiana lamb.), a north american boreal conifer with large longitudinal distribution, was investigated to test for the possible existence of a genetically distinct lineage in the maritimes region in northeastern north america, which could be indicative of a mid-latitude coastal refuge during the last glaciation. • methods: one maternally inherited mitochondrial dna (mtdna) minisatellite marker and four paternally inherited chlor ...201021616829
evolution of conifer diterpene synthases: diterpene resin acid biosynthesis in lodgepole pine and jack pine involves monofunctional and bifunctional diterpene synthases.diterpene resin acids (dras) are major components of pine (pinus spp.) oleoresin. they play critical roles in conifer defense against insects and pathogens and as a renewable resource for industrial bioproducts. the core structures of dras are formed in secondary (i.e. specialized) metabolism via cycloisomerization of geranylgeranyl diphosphate (ggpp) by diterpene synthases (ditpss). previously described gymnosperm ditpss of dra biosynthesis are bifunctional enzymes that catalyze the initial bic ...201223370714
characterizing the physical and genetic structure of the lodgepole pine × jack pine hybrid zone: mosaic structure and differential introgression.understanding the physical and genetic structure of hybrid zones can illuminate factors affecting their formation and stability. in north-central alberta, lodgepole pine (pinus contorta dougl. ex loud. var. latifolia) and jack pine (pinus banksiana lamb) form a complex and poorly defined hybrid zone. better knowledge of this zone is relevant, given the recent host expansion of mountain pine beetle into jack pine. we characterized the zone by genotyping 1998 lodgepole, jack pine, and hybrids from ...201223346232
[effects of tree age and basal area on boreal forest tree mortality in canada].taking the poplar (populus spp.), jack pine (pinus banksiana), and black spruce (picea mariana) in northern canada as test objects, a repeated investigation was conducted on the living and dead trees at 134 fixed sampling plots, and linear regression models were applied to study the effects of tree age, basal area, and stand type on the mortality of the three tree species. generally, the tree mortality increased with increasing tree age and basal area. poplar had a higher mortality in jack pine ...201122126065
variations in foliar monoterpenes across the range of jack pine reveal three widespread chemotypes: implications to host expansion of invasive mountain pine beetle.the secondary compounds of pines (pinus) can strongly affect the physiology, ecology and behaviors of the bark beetles (coleoptera: curculionidae, scolytinae) that feed on sub-cortical tissues of hosts. jack pine (pinus banksiana) has a wide natural distribution range in north america (canada and usa) and thus variations in its secondary compounds, particularly monoterpenes, could affect the host expansion of invasive mountain pine beetle (dendroctonus ponderosae), which has recently expanded it ...201526042134
pheromone production by an invasive bark beetle varies with monoterpene composition of its naïve host.the secondary chemistry of host plants can have cascading impacts on the establishment of new insect herbivore populations, their long-term population dynamics, and their invasion potential in novel habitats. mountain pine beetle, dendroctonus ponderosae hopkins (coleoptera: curculionidae) has recently expanded its range into forests of jack pine, pinus banksiana lamb., in western canada. we investigated whether variations in jack pine monoterpenes affect beetle pheromone production, as the prim ...201526014128
climate-diameter growth relationships of black spruce and jack pine trees in boreal ontario, predict the long-term effects of climate change - global warming and changes in precipitation - on the diameter (radial) growth of jack pine (pinus banksiana lamb.) and black spruce (picea mariana [mill.] b.s.p.) trees in boreal ontario, we modified an existing diameter growth model to include climate variables. diameter chronologies of 927 jack pine and 1173 black spruce trees, growing in the area from 47°n to 50°n and 80°w to 92°w, were used to develop diameter growth models in a nonlinear ...201223504788
water-deficit and fungal infection can differentially affect the production of different classes of defense compounds in two host pines of mountain pine beetle.bark beetles are important agents of tree mortality in conifer forests and their interaction with trees is influenced by host defense chemicals, such as monoterpenes and phenolics. since mountain pine beetle (dendroctonus ponderosae hopkins) has expanded its host range from lodgepole pine (pinus contorta doug. ex loud. (var. latifolia engelm.))-dominated forests to the novel jack pine (pinus banksiana lamb.) forests in western canada, studies investigating the jack pine suitability as a host for ...201627881799
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