[genetic diversity of isoenzymes in mountain pine (pinus mugo turra) in natural populations in the ukrainian carpathian mountains].electrophoretic spectra of got, gdh, dia, mdh, sod, fdh, adh, acp, idh enzymes in the megagametophytes of seeds of 69 mountain pine (pinus mugo turra) trees from natural populations of the ukrainian carpathian mountains have been described. 19 loci products had efficient electrophoretic separation. the analysis of alleles segregation of the heterozygous trees on the whole confirms monogenic inheritance of the discovered variants.200011213632
genetic composition and diploid hybrid speciation of a high mountain pine, pinus densata, native to the tibetan plateau.pinus densata has been suggested to have originated from hybridization events involving p. tabulaeformis and p. yunnanensis. in this study, allozyme differentiation at 12 loci was studied in 14 populations of p. tabulaeformis, p. densata, and p. yunnanensis from china. the observed genetic composition of p. densata supported the hybrid hypothesis and showed varying degrees of contribution from p. yunnanensis and p. tabulaeformis among its populations. these data, together with previous chloropla ...200111560909
polysaccharides in pollen. ii. the xylogalacturonan from mountain pine (pinus mugo turra) pollen. 196514320663
leptographium longiclavatum sp. nov., a new species associated with the mountain pine beetle, dendroctonus ponderosae.the mountain pine beetle, dendroctonus ponderosae, and its fungal associates are devastating the lodgepole pine forests in british columbia, canada. during our fungal survey, an unknown leptographium species has been consistently isolated from both d. ponderosae and infested lodgepole pine (pinus contorta var. latifolia). this leptographium species has similar morphology with the leptographium anamorph of ophiostoma clavigerum whose association with the d. ponderosae is well known. however, thor ...200516279410
genetic population structure of three armillaria species at the landscape scale: a case study from swiss pinus mugo forests.armillaria species are plant pathogens that cause armillaria root rot and are known to cause mortality of mountain pines (pinus mugo) in the swiss national park in the central alps. the identity of isolates and the spatially explicit population structure of the armillaria species were investigated in a 3.3km(2) study area in the swiss national park. in total, 242 armillaria isolates, 205 from wood samples and 37 from epiphytic rhizomorphs, were collected. species were identified using haploid-di ...200616616839
phytoparasitic nematodes of pinus mugo turra in the highlands of the ukrainian carpatihans. 199916889001
effectiveness of bifenthrin (onyx) and carbaryl (sevin sl) for protecting individual, high-value conifers from bark beetle attack (coleoptera: curculionidae: scolytinae) in the western united states.high-value trees, such as those located in residential, recreational, or administrative sites, are particularly susceptible to bark beetle (coleoptera: curculionidae: scolytinae) attack as a result of increased amounts of stress associated with drought, soil compaction, mechanical injury, or vandalism. tree losses in these unique environments generally have a substantial impact. the value of these individual trees, cost of removal, and loss of esthetics may justify protection until the main thru ...200617066800
investigation of pinus mugo essential oil oxygenated fraction by combined use of gas chromatography and dry column chromatography.the oxygenated compounds of pinus mugo turra essential oil were investigated by a combination of gc and dry column chromatography (dcc) coordinated by gc data processing. the collected data resulted in a bar graph ("normalized" gas chromatogram) giving the rrt's and relative amounts of 68 components; 38 of them were identified by ms and ir. the described procedure may be used for essential oil analysis in general.198117402006
dietary benefits of fungal associates to an eruptive herbivore: potential implications of multiple associates on host population dynamics.we used the mountain pine beetle (dendroctonus ponderosae hopkins) and its two fungal associates, grosmannia clavigera and ophiostoma montium, to study potential nutritional benefits of fungi to bark beetles. we tested for potential effects of feeding on phloem colonized by fungi on beetle performance in field and laboratory studies. the fungi increased nitrogen levels in the phloem of attacked trees by 40%, indicating that it may be an important source of dietary nitrogen for mountain pine beet ...200718284766
[soil microarthropods and macrofauna in monsoon tropical forests of cat tien and bi dup-nui ba national parks, southern vietnam].the abundance, biomass, vertical distribution, and taxonomic composition of soil invertebrates (springtails, macrofauna, and termites) were studied in forest formations differing in edaphic and climatic conditions: lowland forests dominated by lagerstroeomia spp. or dipterocarpus spp. in the cat tien national park and in a mountain pine (pinus kesiya) forest on the da lat plateau, southern vietnam. in the lowland forests, springtails had a relatively low density (10000-12000 ind./m2), but their ...200718038627
frost drought in conifers at the alpine timberline: xylem dysfunction and adaptations.drought stress can cause xylem embolism in trees when the water potential (psi) in the xylem falls below specific vulnerability thresholds. at the alpine timberline, frost drought is known to cause excessive winter embolism unless xylem vulnerability or transpiration is sufficiently reduced to avoid critical psi. we compared annual courses of psi and embolism in picea abies, pinus cembra, pinus mugo, larix decidua, and juniperus communis growing at the timberline vs. low altitude. in addition, v ...200617249241
[fire and pinus mugo turra communities in the western alps (susa valley, italy) during the lateglacial-holocene transition: an evidence of refugia area].in western italian alps, small distinct populations of pinus mugo turra raise some questions concerning its ecological status and dynamics in the occidental alps. this note present new palaeobotanical data based on cone imprints of pinus mugo, identified in travertine systems located in the val di susa and dated back to the late dryas (11506+/-66 bp) and the early holocene (10145+/-225 et 9475+/-670 bp). heliophilous species and charcoal fragments were also identified, testifying to the oldness ...200616797455
mountain pine beetle and forest carbon feedback to climate change.the mountain pine beetle (dendroctonus ponderosae hopkins, coleoptera: curculionidae, scolytinae) is a native insect of the pine forests of western north america, and its populations periodically erupt into large-scale outbreaks. during outbreaks, the resulting widespread tree mortality reduces forest carbon uptake and increases future emissions from the decay of killed trees. the impacts of insects on forest carbon dynamics, however, are generally ignored in large-scale modelling analyses. the ...200818432244
a test of high-dose verbenone for stand-level protection of lodgepole and whitebark pine from mountain pine beetle (coleoptera: curculionidae: scolytinae) attacks.the efficacy of verbenone as a stand-level protectant against mountain pine beetle, dendroctonus ponderosae hopkins, attacks was tested in lodgepole and whitebark pine stands at five geographically separated sites, including three consecutive years at one site. forty and 20 high-dose pouches, with a verbenone emission rate up to 50 mg/d per pouch, were spaced in a grid pattern throughout 0.40-ha plots, replicated up to six times at each site. although the verbenone treatment did not prevent beet ...200516334331
cu/zn superoxide dismutase and catalase activities in pinus mugo needles growing at elevated stands in the mountains, and their photochemical efficiency of psii.pinus mugo needles were sampled at different altitudes (1420, 1590 and 1920 m a.s.l.) to analyse levels of oxidative stress and changes in maximum photochemical efficiency of psii. polyacrylamide gel electrophoresis demonstrated that almost all superoxide dismutase activity represented cu/zn superoxide dismutase, and only 4-6% represents mn superoxide dismutase. in extracts from plants sampled at 1590 and 1920 m a.s.l., lower activity of cu/zn superoxide dismutase was found. comparing these data ...200516146315
polychlorinated biphenyls in mountain pine (pinus uncinata) needles from central pyrenean high mountains (catalonia, spain).the polychlorobiphenyl (pcb) composition of pine needles of pinus uncinata from the pyrenean high mountains has been investigated. samples from four altitudes (1750, 1950, 2150, and 2250 m above sea level) were collected in march 2002 and june 2002 in a central area near lake redon. the observed concentrations were similar to those found in pine trees from rural areas in europe. a correlation between log-transformed pcb concentrations and reciprocal of absolute average air temperature was observ ...200616051360
susceptibility to low-temperature photoinhibition in three conifers differing in successional status.susceptibility to photoinhibition of the evergreen conifers abies alba mill., picea abies (l.) karst. and pinus mugo turra was investigated in an unheated greenhouse during winter and spring 2003. photosynthetic performance of the seedlings was assessed by chlorophyll a fluorescence and analyses of chlorophyll and total carotenoid concentrations in needles. during winter months, maximum quantum yield of psii photochemistry (ratio of variable to maximum fluorescence, fv/fm) was significantly grea ...200515996958
an analytical protocol for the determination of total mercury concentrations in solid peat samples.traditional peat sample preparation methods such as drying at high temperatures and milling may be unsuitable for hg concentration determination in peats due to the possible presence of volatile hg species, which could be lost during drying. here, the effects of sample preparation and natural variation on measured hg concentrations are investigated. slight increases in mercury concentrations were observed in samples dried at room temperature and at 30 degrees c (6.7 and 2.48 ng kg(-1) h(-1), res ...200212108441
mountain pine beetle attack associated with low levels of 4-allylanisole in ponderosa pine.mountain pine beetle (dendroctonus ponderosae) is the most important insect pest in southern rocky mountain ponderosa pine (pinus ponderosa) forests. tree mortality is hastened by the various fungal pathogens that are symbiotic with the beetles. the phenylpropanoid 4-allylanisole is an antifungal and semiochemical for some pine beetle species. we analyzed 4-allylanisole and monoterpene profiles in the xylem oleoresin from a total of 107 trees at six sites from two chemotypes of ponderosa pine fo ...200818801251
genetic diversity and the presence of two distinct groups in ophiostoma clavigerum associated with dendroctonus ponderosae in british columbia and the northern rocky mountains.abstract the sapstaining fungal pathogen ophiostoma clavigerum is associated with the mountain pine beetle (dendroctonus ponderosae), which is currently the most destructive forest pest in north america. the genetic diversity of o. clavigerum populations collected from five sites in canada and two sites in the united states was estimated with amplified fragment length polymorphism (aflp) analysis. genomic dna from 170 o. clavigerum isolates was digested with ecori and psti and amplified with six ...200718944182
first in line or first in time? effects of settlement order and arrival date on reproduction in a group-living beetle dendroctonus ponderosae.1. in group-living organisms, individuals that initiate aggregations, termed pioneers, may suffer higher mortality costs than individuals that join established aggregations. here we examine the hypothesis that aggregation initiators achieve higher reproductive success in the early phases of colonization, potentially through lower competition and increased access to the resource (finder's advantage), and that this benefit is sufficient to outweigh the costs of pioneering. 2. we also examine the r ...200919292705
inheritance and subcellular localization of triose-phosphate isomerase in dwarf mountain pine (pinus mugo).several trees with expected heterozygous phenotype for triose-phosphate isomerase (tpi) were discovered in a population of dwarf mountain pine (pinus mugo turra) from southern poland. as the inheritance of this enzyme in pines has not been reported, segregation of allelic variants was tested in eight trees with putative heterozygous phenotypes for two loci, tpia and tpib: linkage between these and some other isozyme loci were studied and evidence for linkage has been found between tpia and pgda ...200111447244
transformation of presumptive precursors to frontalin and exo-brevicomin by bark beetles and west indian sugarcane weevil (coleoptera).(z)-6-nonen-2-one (1) has recently been shown to be the biosynthetic precursor for the aggregation pheromone exo-brevicomin (2) in mountain pine beetle (mpb) males, dendroctonus ponderosae (hopkins). we tested the hypotheses that (1) 6-methyl-6-hepten-2-one (3) is the biosynthetic precursor for the aggregation pheromone frontalin (4) in the spruce beetle (sb), dendroctonus rufipennis (kirby), and (2) that frontalin and exo-brevicomin are produced from 3 and 1, respectively, only by beetles that ...19968733625
isolation of functional rna from plant tissues rich in phenolic compounds.a method for the isolation of rna from different tissues of trees (seedlings, saplings, and adult trees) is described. using this procedure it is possible to remove large amounts of disturbing polyphenolic compounds from nucleic acids. the method involves an acetone treatment of the freeze-dried and powdered plant material, the use of high salt concentrations in the extraction buffer and an aqueous two-phase system. these steps were combined with the conventional phenol/chloroform extraction and ...19911719845
acid-catalyzed steam pretreatment of lodgepole pine and subsequent enzymatic hydrolysis and fermentation to ethanol.utilization of ethanol produced from biomass has the potential to offset the use of gasoline and reduce co(2) emissions. this could reduce the effects of global warming, one of which is the current outbreak of epidemic proportions of the mountain pine beetle (mpb) in british columbia (bc), canada. the result of this is increasing volumes of dead lodgepole pine with increasingly limited commercial uses. bioconversion of lodgepole pine to ethanol using so(2)-catalyzed steam explosion was investiga ...200717385749
the monoterpene terpinolene from the oil of pinus mugo l. in concert with alpha-tocopherol and beta-carotene effectively prevents oxidation of ldl.antioxidants from several nutrients, e.g. vitamin e, beta-carotene, or flavonoids, inhibit the oxidative modification of low-density lipoproteins. this protective effect could possibly retard atherogenesis and in consequence avoid coronary heart diseases. some studies have shown a positive effect of those antioxidants on cardiovascular disease. another class of naturally occurring antioxidants are terpenoids, which are found in essential oils. the essential oil of pinus mugo and the contained mo ...200516008117
efficacy of verbenone for protecting ponderosa pine stands from western pine beetle (coleoptera: curculionidae: scolytinae) attack in california.the western pine beetle, dendroctonus brevicomis leconte (coleoptera: curculionidae: scolytinae), is a major cause of ponderosa pine, pinus ponderosa dougl. ex laws., mortality in much of western north america. currently, techniques for managing d. brevicomis infestations are limited. verbenone (4,6,6-trimethylbicyclo [3.1.1] hept-3-en-2-one) is an antiaggregation pheromone of several dendroctonus spp., including d. brevicomis, and it has been registered as a biopesticide for control of mountain ...200919886449
agrobacterium-meditated gene disruption using split-marker in grosmannia clavigera, a mountain pine beetle associated pathogen.grosmannia clavigera is a fungal pathogen associated with the mountain pine beetle (dendroctonus ponderosae) which is devastating large areas of western canada's conifer forests. this fungus also produces a dark melanin pigment that discolors pine sapwood. we have generated the draft genome of g. clavigera. however, functional characterization of genes identified in the genome sequence requires an efficient gene disruption method. in this work, we report a gene replacement strategy for g. clavig ...201020229292
characterization of glutathione s-transferase from dwarf pine needles (pinus mugo turra).glutathione s-transferase activity conjugating xenobiotics with glutathione (gsh) was found in extracts from needles of dwarf pine (pinus mugo turra). in vivo incubation of needle segments with the herbicide fluorodifen at 25 degrees c resulted in conversion of the xenobiotic to water-soluble products at initial rates of 0.7 nmol h(-1) g(fw) (-1). at 15 degrees c, the initial rate of product formation was decreased to 0.1 nmol h(-1) g(fw) (-1). in vitro conjugation studies with chloro-2,4-dinitr ...199214969958
photosynthetic functions of cembran pines and dwarf pines during winter at timberline as regulated by different temperatures, snowcover and light.trees at timberline in the high alps are exposed to a variety of climatic conditions. most climatic stresses occur during winter and spring, when frost, occasionally low snow cover, and high irradiation interact. in this study, we follow reactions of photosynthesis from high winter to spring in two dominating tree species of the alpine timberline, which may indicate the status of stress response to a changing environment. the results indicate a level of physiological stability in trees, which ar ...200312685031
[genetic variation and differentiation of peat-bog and dry-meadow populations of the dwarf mountain pine pinus mugo turra in the highlands of the ukrainian carpathians].based on electrophoretic analysis of 21 isozyme loci controlling 10 enzyme systems, the intra- and inter-population variation was studied in two peat-bog and three dry-meadow populations of the dwarf mountain pine pinus mugo turra from the highlands of the ukrainian carpathians. in the studied samples (a total of 164 trees), on average 62% of the studied genes were polymorphic; the mean heterozygosity was 21.3%. the dry-meadow populations differed from the peat-bog populations by allele and geno ...200212391884
a 400-year tree-ring chronology from the tropical treeline of north america.high-elevation sites in the tropics may be particularly sensitive to rapid climate change. by sampling treeline populations, i have developed the first extensive (> 300 years) tree-ring chronology in tropical north america. the site is nevado de colima, at the western end of the mexican neovolcanic belt, and the species studied is mexican mountain pine (pinus hartwegii). despite past logging in the area, 300 to 500-year old pines were found at 3600-3700 m elevation, about 300 m below the present ...200111436664
on the specific pattern of long chain polyprenols in green needles of pinus mugo green needles of pinus mugo the most abundant polyprenols occur as a mixture of prenologues in which the dominant alcohol is built of 16 isoprene units. the characteristic spectrum of polyprenols (prenol-15, -16 and -17) was the same irrespective of the location of plant and of distinct morphological differences observed in the various selected forms of this species. the constant pattern of the polyprenols spectrum was preserved throughout the 2-year life span of needles, although the level o ...19979584863
light-independent and light-dependent protochlorophyllide-reducing activities and two distinct nadph-protochlorophyllide oxidoreductase polypeptides in mountain pine (pinus mugo).lower plants and gymnosperms synthesize chlorophyll and develop photosynthetically competent chloroplasts even when grown in the dark. in cell-free extracts of pine (pinus mugo, turra, ssp. mugo) seedlings, light-independent and light-dependent protochlorophyllide-reducing activities are present. two distinct nadph-protochlorophyllide-oxidoreductase (por) polypeptides can be detected immunologically with an antiserum raised against the por of barley. the subcellular localization and amounts of t ...19937763825
influences of secondary disturbances on lodgepole pine stand development in rocky mountain national park.although high-severity fire is the primary type of disturbance shaping the structure of lodgepole pine (pinus contorta) stands in the southern rocky mountains, many post-fire stands are also affected by blowdown, low-severity surface fires, and/or outbreaks of mountain pine beetle (mpb; dendroctonus ponderosae). the ecological effects of these secondary disturbances are poorly understood but are potentially important in the context of managing for ecological restoration and fire hazard mitigatio ...200717913129
growth responses to climate in a multi-species tree-ring network in the western carpathian tatra mountains, poland and slovakia.we analyzed growth responses to climate of 24 tree-ring width and four maximum latewood density chronologies from the greater tatra region in poland and slovakia. this network comprises 1183 ring-width and 153 density measurement series from four conifer species (picea abies (l.) karst., larix decidua mill., abies alba (l.) karst., and pinus mugo (l.)) between 800 and 1550 m a.s.l. individual spline detrending was used to retain annual to multi-decadal scale climate information in the data. twen ...200717267360
antioxidative properties of the essential oil from pinus mugo.the essential oil from pinus mugo (pmeo) was tested on its antioxidative capacity. for this purpose, several biochemical test systems were chosen (e.g., the fenton system, the xanthine oxidase assay, or the copper-induced oxidation of low-density lipoprotein (ldl)). the results show that there is moderate or weak antioxidative activity when tested in aqueous environments, like in the fenton system, xanthine oxidase induced superoxide radical formation, or in the hocl driven fragmentation of 1-am ...200314664510
generation and annotation of lodgepole pine and oleoresin-induced expressed sequences from the blue-stain fungus ophiostoma clavigerum, a mountain pine beetle-associated pathogen.ophiostoma clavigerum is a destructive pathogen of lodgepole pine (pinus contorta) forests in western north america. it is therefore a relevant system for a genomics analysis of fungi vectored by bark beetles. to begin characterizing molecular interactions between the pathogen and its conifer host, we created an expressed sequence tag (est) collection for o. clavigerum. lodgepole pine sawdust and oleoresin media were selected to stimulate gene expression that would be specific to this host inter ...200717328114
in vitro interactions between yeasts and bacteria and the fungal symbionts of the mountain pine beetle (dendroctonus ponderosae).multi-trophic interactions between prokaryotes, unicellular eukaryotes, and ecologically intertwined metazoans are presumably common in nature, yet rarely described. the mountain pine beetle, dendroctonus ponderosae, is associated with two filamentous fungi, grosmannia clavigera and ophiostoma montium. other microbes, including yeasts and bacteria, are also present in the phloem, but it is not known whether they interact with the symbiotic fungi or the host beetle. to test whether such interacti ...200818322728
genome and transcriptome analyses of the mountain pine beetle-fungal symbiont grosmannia clavigera, a lodgepole pine western north america, the current outbreak of the mountain pine beetle (mpb) and its microbial associates has destroyed wide areas of lodgepole pine forest, including more than 16 million hectares in british columbia. grosmannia clavigera (gc), a critical component of the outbreak, is a symbiont of the mpb and a pathogen of pine trees. to better understand the interactions between gc, mpb, and lodgepole pine hosts, we sequenced the ~30-mb gc genome and assembled it into 18 supercontigs. we p ...201121262841
pesticide treatments affect mountain pine beetle abundance and woodpecker foraging british columbia, canada, management efforts used to control mountain pine beetle (dendroctonus ponderosae hopkins) outbreaks have included treatment of infested trees with an organic arsenic pesticide, monosodium methanearsonate (msma). cumulative pesticide applications over a large geographic area have generated concerns about arsenic loading in the environment and potential toxicity to nontarget wildlife. we investigated woodpecker foraging patterns in infested stands with and without msma ...200818372564
ectomycorrhizal fungal communities on seedlings and conspecific trees of pinus mugo grown on the coastal dunes of the curonian spit in lithuania.ectomycorrhizal (ecm) communities of mature trees and regenerating seedlings of a non-native tree species pinus mugo grown in a harsh environment of the coastal region of the curonian spit national park in lithuania were assessed. we established three study sites (s1, s2, and s3) that were separated from each other by 15 km. the ecm species richness was rather low in particular for mature, 100-year-old trees: 12 ectomycorrhizal taxa were identified by molecular analysis from 11 distinguished mor ...201020938693
different patterns of genetic structure of relict and isolated populations of endangered peat-bog pine (pinus uliginosa neumann).recent changes in environmental conditions in populations of peat-bog pine (pinus uliginosa neumann) caused rapid decline or even extinction of the species in several stands in central europe. conservation strategies for p. uliginosa require information about the evolutionary history and genetic structure of its populations. using isozymes we assessed the genetic structure of p. uliginosa from four isolated stands in poland and compared the results to genetic structures of other closely related ...200919875883
isolation and characterization of 16 microsatellite loci in the mountain pine beetle, dendroctonus ponderosae hopkins (coleoptera: curculionidae: scolytinae).we isolated 16 polymorphic microsatellite loci in the mountain pine beetle (dendroctonus ponderosae hopkins) and developed conditions for amplifying these markers in four multiplex reactions. three to 14 alleles were detected per locus across two sampled populations. observed and expected heterozygosities ranged from 0.000 to 0.902 and from 0.100 to 0.830, respectively. three loci deviated from hardy-weinberg equilibrium in one sampled population. one of these loci may be sex linked. these marke ...200921564842
rhizosphere dynamics during phytoremediation of olive mill wastewater.the potential of phytoremediation as a treatment option for olive mill wastewater (omw) was tested on five perennial tree species. cupressus sempervirens and quercus ilex proved tolerant to six-month omw treatment followed by six-month water irrigation, whereas salix sp. and laurus nobilis and, later, pinus mugo suffered from phytotoxic effects. test plants were compared to controls after treatment and irrigation, by monitoring biochemical and microbiological variations in the rhizosphere soil. ...201021256739
target-specific pcr primers can detect and differentiate ophiostomatoid fungi from microbial communities associated with the mountain pine beetle dendroctonus ponderosae.the aim of this study was to develop dna probes that could identify the major fungal species associated with mountain pine beetles (mpb). the beetles are closely associated with fungal species that include ophiostomatoid fungi that can be difficult to differentiate morphologically. the most frequently isolated associates are the pine pathogens grosmannia clavigera and leptographium longiclavatum, the less pathogenic ophiostoma montium, and an undescribed ceratocystiopsis species (cop. sp.). beca ...201020943192
the bioconversion of mountain pine beetle-killed lodgepole pine to fuel ethanol using the organosolv process.lodgepole pine (pinus contorta) killed by mountain pine beetle (dendroctonus ponderosae) (blp) was compared with healthy lodgepole pine (hlp) for bioconversion to ethanol and high-value co-products. the blp and hlp chips were pretreated using an ethanol organosolv process at a variety of severities. it was shown that the blp was easier to pretreat and delignify than were the hlp chips. the resulting pretreated blp substrate had a lower residual lignin, lower degree of polymerization of cellulose ...200818421796
spray deposition from ground-based applications of carbaryl to protect individual trees from bark beetle attack.bark beetles (coleoptera: curculionidae, scolytinae) are recognized as the most important tree mortality agent in western coniferous forests. a common method of protecting trees from bark beetle attack is to saturate the tree bole with carbaryl (1-naphthyl methylcarbamate) using a hydraulic sprayer. in this study, we evaluate the amount of carbaryl drift (ground deposition) occurring at four distances from the tree bole (7.6, 15.2, 22.9, and 38.1 m) during conventional spray applications for pro ...200818453436
forest health conditions in north america.some of the greatest forest health impacts in north america are caused by invasive forest insects and pathogens (e.g., emerald ash borer and sudden oak death in the us), by severe outbreaks of native pests (e.g., mountain pine beetle in canada), and fires exacerbated by changing climate. ozone and n and s pollutants continue to impact the health of forests in several regions of north america. long-term monitoring of forest health indicators has facilitated the assessment of forest health and sus ...200818479794
competition and coexistence in a multi-partner mutualism: interactions between two fungal symbionts of the mountain pine beetle in beetle-attacked trees.despite overlap in niches, two fungal symbionts of the mountain pine beetle (dendroctonus ponderosae), grosmannia clavigera and ophiostoma montium, appear to coexist with one another and their bark beetle host in the phloem of trees. we sampled the percent of phloem colonized by fungi four times over 1 year to investigate the nature of the interaction between these two fungi and to determine how changing conditions in the tree (e.g., moisture) affect the interaction. both fungi colonized phloem ...200918545867
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
effects of water potential and solute on the growth and interactions of two fungal symbionts of the mountain pine beetle.we investigated the effect of water potential (wp) on the growth of, and interaction between, two ophiostomatoid fungi, grosmannia clavigera and ophiostoma montium, associated with the mountain pine beetle (dendroctonus ponderosae). the wp of malt extract agar was amended by adding potassium chloride (kcl) or sucrose. growth of both fungi decreased with wp on kcl-amended media. growth of g. clavigera also decreased with wp on sucrose-amended media, although growth was stimulated on these media c ...200918640273
habitat area and structure affect the impact of seed predators and the potential for coevolutionary arms races.both habitat patch size and structure affect the abundance and occurrence of species and thereby can affect the ecology and evolution of species interactions. here we contrast the level of seed predation and selection exerted by common crossbills (loxia curvirostra complex) and red squirrels (sciurus vulgaris) in the extensive mountain pine (pinus uncinata) forests in the pyrenees with their level of seed predation in two small, isolated forests. crossbills consumed 5.1 times more seeds in the p ...201020426338
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
synergistic blends of monoterpenes for aggregation pheromones of the mountain pine beetle (coleoptera: curculionidae).the superiority of the host monoterpene myrcene as a synergist for trans-verbenol and exo-brevicomin, aggregation pheromone components of the mountain pine beetle, dendroctonus ponderosae hopkins (coleoptera: curculionidae), suggests that the ancestral host of the mountain pine beetle is a pine rich in myrcene. a field trapping experiment in british columbia testing reconstituted bole oleoresin of whitebark pine, pinus albicaulis engelmann, composed of mainly myrcene (20.7%), terpinolene (6.8%), ...200818767736
seedling insensitivity to ozone for three conifer species native to great smoky mountains national park.field symptoms typical of ozone injury have been observed on several conifer species in great smoky mountains national park, and tropospheric ozone levels in the park can be high, suggesting that ozone may be causing growth impairment of these plants. the objective of this research was to test the ozone sensitivity of selected conifer species under controlled exposure conditions. seedlings of three species of conifers, table mountain pine (pinus pungens), virginia pine (pinus virginiana), and ea ...200015092944
nitrogen concentration in mountain pine beetle larvae reflects nitrogen status of the tree host and two fungal associates.individual lodgepole pines (pinus contorta) were fertilized with urea at nitrogen (n) inputs equivalent to 0, 315, or 630 kg/ha. four months after application of the fertilizer, inner bark tissue n concentrations were significantly higher in the trees that had received the low dose (315 kg/ha) fertilization treatment than in the control trees; trees that had received the high-dose treatment (630 kg/ha) were intermediate and not significantly different from either of the other treatments. there w ...201020550794
draft genome of the mountain pine beetle, dendroctonus ponderosae hopkins, a major forest pest.the mountain pine beetle, dendroctonus ponderosae hopkins, is the most serious insect pest of western north american pine forests. a recent outbreak destroyed more than 15 million hectares of pine forests, with major environmental effects on forest health, and economic effects on the forest industry. the outbreak has in part been driven by climate change, and will contribute to increased carbon emissions through decaying forests.201323537049
antennal transcriptome analysis of the chemosensory gene families in the tree killing bark beetles, ips typographus and dendroctonus ponderosae (coleoptera: curculionidae: scolytinae).the european spruce bark beetle, ips typographus, and the north american mountain pine beetle, dendroctonus ponderosae (coleoptera: curculionidae: scolytinae), are severe pests of coniferous forests. both bark beetle species utilize aggregation pheromones to coordinate mass-attacks on host trees, while odorants from host and non-host trees modulate the pheromone response. thus, the bark beetle olfactory sense is of utmost importance for fitness. however, information on the genes underlying olfac ...201323517120
gene expression analysis of overwintering mountain pine beetle larvae suggests multiple systems involved in overwintering stress, cold hardiness, and preparation for spring development.cold-induced mortality has historically been a key aspect of mountain pine beetle, dendroctonus ponderosae hopkins (coleoptera: curculionidae), population control, but little is known about the molecular basis for cold tolerance in this insect. we used rna-seq analysis to monitor gene expression patterns of mountain pine beetle larvae at four time points during their overwintering period-early-autumn, late-autumn, early-spring, and late-spring. changing transcript profiles over the winter indica ...201627441109
diversity and decay ability of basidiomycetes isolated from lodgepole pines killed by the mountain pine beetle.when lodgepole pines (pinus contorta douglas ex louden var. latifolia engelm. ex s. watson) that are killed by the mountain pine beetle (dendroctonus ponderosae) and its fungal associates are not harvested, fungal decay can affect wood and fibre properties. ophiostomatoids stain sapwood but do not affect the structural properties of wood. in contrast, white or brown decay basidiomycetes degrade wood. we isolated both staining and decay fungi from 300 lodgepole pine trees killed by mountain pine ...201121217795
cloning and characterization of chitinases from interior spruce and lodgepole pine.chitinases have been implicated in the defence of conifers against insects and pathogens. cdna for six chitinases were cloned from interior spruce (picea glauca x engelmannii) and four from lodgepole pine (pinus contorta). the cloned interior spruce chitinases were annotated class i pgechia1-1 and pgechia1-2, class ii pgechia2-1, class iv pgechia4-1, and class vii pgechia7-1 and pgechia7-2; lodgepole pine chitinases were annotated class i pcchia1-1, class iv pcchia4-1, and class vii pcchia7-1 an ...201424564978
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
seeing the forest through the trees: differential dispersal of hylobius warreni within modified forest habitats.hylobius warreni wood, also known as the warren root collar weevil, is a flightless insect that feeds on conifers throughout the boreal forests of canada. mature trees typically can withstand feeding, but larval feeding around the root collar may cause mortality to young trees. recently, a large outbreak of mountain pine beetle (dendroctonus ponderosae hopkins) has killed a high proportion of mature lodgepole pine (pinus contorta douglas variety latifolia) across british columbia, canada. this r ...201020550804
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
fatty acid composition of novel host jack pine do not prevent host acceptance and colonization by the invasive mountain pine beetle and its symbiotic fungus.fatty acids are major components of plant lipids and can affect growth and development of insect herbivores. despite a large literature examining the roles of fatty acids in conifers, relatively few studies have tested the effects of fatty acids on insect herbivores and their microbial symbionts. particularly, whether fatty acids can affect the suitability of conifers for insect herbivores has never been studied before. thus, we evaluated if composition of fatty acids impede or facilitate coloni ...201627583820
fungal volatiles can act as carbon sources and semiochemicals to mediate interspecific interactions among bark beetle-associated fungal symbionts.mountain pine beetle (dendroctonus ponderosae) has killed millions of hectares of pine forests in western north america. beetle success is dependent upon a community of symbiotic fungi comprised of grosmannia clavigera, ophiostoma montium, and leptographium longiclavatum. factors regulating the dynamics of this community during pine infection are largely unknown. however, fungal volatile organic compounds (fvocs) help shape fungal interactions in model and agricultural systems and thus may be im ...201627583519
rapid induction of multiple terpenoid groups by ponderosa pine in response to bark beetle-associated fungi.ponderosa pine (pinus ponderosa) is a major and widely distributed component of conifer biomes in western north america and provides substantial ecological and economic benefits. this tree is exposed to several tree-killing bark beetle-microbial complexes, including the mountain pine beetle (dendroctonus ponderosae) and the phytopathogenic fungus grosmannia clavigera that it vectors, which are among the most important. induced responses play a crucial role in conifer defenses, yet these have not ...201626662358
differences in defence responses of pinus contorta and pinus banksiana to the mountain pine beetle fungal associate grosmannia clavigera are affected by water deficit.we tested the hypotheses that responses to the mountain pine beetle fungal associate grosmannia clavigera will differ between the evolutionarily co-evolved host lodgepole pine (pinus contorta var. latifolia) and the naïve host jack pine (pinus banksiana) and that these responses will be influenced by water availability. g. clavigera inoculation resulted in more rapid stem lesion development in lodgepole than in jack pine; water deficit delayed lesion development in both species. decreased hydrau ...201626205849
bacteria influence mountain pine beetle brood development through interactions with symbiotic and antagonistic fungi: implications for climate-driven host range expansion.bark beetles are associated with diverse communities of symbionts. although fungi have received significant attention, we know little about how bacteria, and in particular their interactions with fungi, affect bark beetle reproduction. we tested how interactions between four bacterial associates, two symbiotic fungi, and two opportunistic fungi affect performance of mountain pine beetles (dendroctonus ponderosae) in host tissue. we compared beetle performance in phloem of its historical host, lo ...201526037523
whitebark pine vulnerability to climate-driven mountain pine beetle disturbance in the greater yellowstone ecosystem.widespread outbreaks of mountain pine beetles (mpb) are occurring throughout the range of this native insect. episodic outbreaks are a common occurrence in the beetles' primary host, lodgepole pine. current outbreaks, however, are occurring in habitats where outbreaks either did not previously occur or were limited in scale. herein, we address widespread, ongoing outbreaks in high-elevation, whitebark pine forests of the greater yellowstone ecosystem, where, due to an inhospitable climate, past ...201020597278
a new, isolated and endangered relict population of dwarf pine (pinus mugo turra) in the northwestern alps.dwarf pines were discovered in 2004 during a paleoecological survey in the mont cenis massif (savoy, france). these dwarf pines are the sole natural and spontaneous population in the nw french alps of pinus mugo turra, ssp. mughus (scop.) o. schwarz. the population, fragile in light of the individual numbers, is currently isolated, but likely results from populations that would have covered larger areas during the lateglacial or the early-holocene, from the sw alps (france) toward the mont cenis ...200919393977
cryptic speciation and community structure of herpotrichia juniperi, the causal agent of brown felt blight of conifers.conifer twigs showing brown felt blight were collected along 100-m long transects at the timberline in the swiss alps and single-hyphal-tip cultures were prepared. forty-seven of the sequenced 48 strains were herpotrichia juniperi based on sequence comparisons of the internal transcribed spacers (its). a non-sporulating strain was tentatively identified as another, undescribed herpotrichia species. herpotrichia coulteri was not isolated. most strains were from juniperus communis var. saxatilis, ...200919450682
rapid identification and detection of pine pathogenic fungi associated with mountain pine beetles by padlock probes.fifteen million hectares of pine forests in western canada have been attacked by the mountain pine beetle (dendroctonus ponderosae; mpb), leading to devastating economic losses. grosmannia clavigera and leptographium longiclavatum, are two fungi intimately associated with the beetles, and are crucial components of the epidemic. to detect and discriminate these two closely related pathogens, we utilized a method based on ligase-mediated nucleotide discrimination with padlock probe technology, and ...201020650291
comparing the impacts of mitigation and non-mitigation on mountain pine beetle populations.mountain pine beetles, dendroctonus ponderosae (hopkins) attack and can ultimately kill individuals and groups of pine trees, specifically lodgepole pine (pinus contorta dougl. ex. loud var. latifolia engl.). in british columbia, beetle attack has increased from 164 000 ha in 1999 to over 13 million ha in 2008. mitigation efforts can play a key role in addressing the impact beetle infestations can have on the forested landscape. in this research, the impact of mitigation on a mountain pine beetl ...201120855146
influence of water deficit on the molecular responses of pinus contorta × pinus banksiana mature trees to infection by the mountain pine beetle fungal associate, grosmannia clavigera.conifers exhibit a number of constitutive and induced mechanisms to defend against attack by pests and pathogens such as mountain pine beetle (dendroctonus ponderosae hopkins) and their fungal associates. ecological studies have demonstrated that stressed trees are more susceptible to attack by mountain pine beetle than their healthy counterparts. in this study, we tested the hypothesis that water deficit affects constitutive and induced responses of mature lodgepole pine × jack pine hybrids (pi ...201424319029
ultrasonic emissions from conifer xylem exposed to repeated freezing.ultrasonic emission measurements enable the analysis of xylem cavitation induced by drought and freeze-thaw events. several studies have indicated that ultrasonic acoustic emissions (uae) in conifers occur upon freezing and not upon thawing, although classical theory has postulated gas bubble formation during freezing and cavitation during thawing. we analyzed the pattern and quality of freeze-thaw-induced uae in seven conifers (abies alba, larix decidua, juniperus communis, picea abies, pinus c ...201019692146
lodgepole pine: the first evidence of seed-based somatic embryogenesis and the expression of embryogenesis marker genes in shoot bud cultures of adult trees.of the various alternatives for cloning elite conifers, somatic embryogenesis (se) appears to be the best option. in recent years, significant areas of lodgepole pine (pinus contorta) forest have been devastated by the mountain pine beetle (mpb) in western canada. in an attempt to establish an se propagation system for mpb-resistant lodgepole pine, several families displaying varying levels of resistance were selected for experimentation involving shoot bud and immature seed explants. in bud cul ...201020935320
the effect of varying organosolv pretreatment chemicals on the physicochemical properties and cellulolytic hydrolysis of mountain pine beetle-killed lodgepole pine.mountain pine beetle-killed lodgepole pine (pinus contorta) chips were pretreated using the organosolv process, and their ease of subsequent enzymatic hydrolysis was assessed. the effect of varying pretreatment chemicals and solvents on the substrate's physicochemical characteristics was also investigated. the chemicals employed were mgcl2, h2so4, so2, and naoh, and the solvents were ethanol and butanol. it was apparent that the different pretreatments resulted in variations in both the chemical ...201019820908
seed release in serotinous lodgepole pine forests after mountain pine beetle outbreak.there are concerns that large-scale stand mortality due to mountain pine beetle (mpb) could greatly reduce natural regeneration of serotinous rocky mountain (rm) lodgepole pine (pinus contorta var. latifolia) because the closed cones are held in place without the fire cue for cone opening. we selected 20 stands (five stands each of live [control], 3 years since mpb [3-yr-mpb], 6 years since mpb [6-yr-mpb], and 9 years since mpb [9-yr-mpb] mortality) in north central british columbia, canada. the ...201121516894
characterization of microsatellite loci in the fungus, grosmannia clavigera, a pine pathogen associated with the mountain pine beetle.the largest forest pest epidemic in canadian history caused by the mountain pine beetle (mpb) and its fungal associates has killed over 15 million hectares of forest. sixty simple sequence repeat regions were identified from grosmannia clavigera, an mpb associated fungus. eight loci genotyped in 53 isolates from two populations in british columbia, canada revealed three to 10 alleles per locus and gene diversities of 0 to 0.79. all but two of these loci showed length polymorphism in leptographiu ...200921564944
the hydraulic conductivity of the xylem in conifer needles (picea abies and pinus mugo).main resistances of the plant water transport system are situated in leaves. in contrast to angiosperm leaves, knowledge of conifer needle hydraulics and of the partitioning of resistances within needles is poor. a new technique was developed which enabled flow-meter measurements through needles embedded in paraffin and thus quantification of the specific hydraulic conductivity (k(s)) of the needle xylem. in picea abies, xylem k(s) of needle and axes as well as in needles of different age were c ...201121593348
responses of bark beetle-associated bacteria to host monoterpenes and their relationship to insect life histories.bark beetles that colonize living conifers and their microbial associates encounter constitutive and induced chemical defenses of their host. monoterpene hydrocarbons comprise a major component of these allelochemicals, and many are antibiotic to insects, fungi, and bacteria. some bark beetle species exhaust these defenses by killing their host through mass attacks mediated by aggregation pheromones. others lack adult aggregation pheromones and do not engage in pheromone-mediated mass attacks, b ...201121710365
the impact of phloem nutrients on overwintering mountain pine beetles and their fungal the low nutrient environment of conifer bark, subcortical beetles often carry symbiotic fungi that concentrate nutrients in host tissues. although bark beetles are known to benefit from these symbioses, whether this is because they survive better in nutrient-rich phloem is unknown. after manipulating phloem nutrition by fertilizing lodgepole pine trees (pinus contorta douglas var. latifolia), we found bolts from fertilized trees to contain more living individuals, and especially more pupae an ...201222732605
differential effects of plant ontogeny and damage type on phloem and foliage monoterpenes in jack pine (pinus banksiana).coniferous trees have both constitutive and inducible defences that deter or kill herbivores and pathogens. we investigated constitutive and induced monoterpene responses of jack pine (pinus banksiana lamb.) to a number of damage types: a fungal associate of the mountain pine beetle (dendroctonus ponderosae hopkins), grosmannia clavigera (robinson-jeffrey & r.w. davidson); two phytohormones, methyl jasmonate (mj) and methyl salicylate (ms); simulated herbivory; and mechanical wounding. we only i ...201222659460
laboratory assays of select candidate insecticides for control of dendroctonus ponderosae.the mountain pine beetle, dendroctonus ponderosae hopkins (coleoptera: curculionidae, scolytinae), is the most destructive bark beetle in western north america. dendroctonus ponderosae can be prevented from successfully colonizing and killing individual trees by ground-based sprays of insecticides applied directly to the tree bole. however, the future availability of several active ingredients, including carbaryl which is most commonly used in the western united states, is uncertain. two novel i ...201121472972
viability of forest floor and canopy seed banks in pinus contorta var. latifolia (pinaceae) forests after a mountain pine beetle outbreak.• premise of the study: seed banks are important for the natural regeneration of many forest species. most of the seed bank of serotinous lodgepole pine is found in the canopy, but after an outbreak of mountain pine beetle (mpb), a considerable forest-floor seed bank develops through the falling of canopy cones. after large-scale mortality of pine stands from mpb, however, the viability of seeds in both the canopy and the forest-floor cone bank is uncertain. • methods: we sampled cones in five s ...201121613163
Population structure and migration pattern of a conifer pathogen, Grosmannia clavigera, as influenced by its symbiont, the mountain pine beetle.We investigated the population structure of Grosmannia clavigera (Gc), a fungal symbiont of the mountain pine beetle (MPB) that plays a crucial role in the establishment and reproductive success of this pathogen. This insect-fungal complex has destroyed over 16 million ha of lodgepole pine forests in Canada, the largest MPB epidemic in recorded history. During this current epidemic, MPB has expanded its range beyond historically recorded boundaries, both northward and eastward, and has now reach ...201222118059
pest and disease management: why we shouldn't go against the grain.given the wide range of scales and mechanisms by which pest or disease agents disperse, it is unclear whether there might exist a general relationship between scale of host heterogeneity and spatial spread that could be exploited by available management options. in this model-based study, we investigate the interaction between host distributions and the spread of pests and diseases using an array of models that encompass the dispersal and spread of a diverse range of economically important speci ...201324098739
capturing community context of human response to forest disturbance by insects: a multi-method assessment.the socioeconomic and environmental features of local places (community context) influence the relationship between humans and their physical environment. in times of environmental disturbance, this community context is expected to influence human perceptual and behavioral responses. residents from nine colorado communities experiencing a large outbreak of mountain pine beetles (dendroctonus ponderosae) were surveyed in 2007. multiple analytic methods including ordinary least squares regression ...201022207775
speciation history of three closely related pines pinus mugo (t.), p. uliginosa (n.) and p. sylvestris (l.).nucleotide polymorphisms at genomic regions including 17 nuclear loci, two chloroplast and one mitochondrial dna fragments were used to study the speciation history of three pine species: dwarf mountain pine (pinus mugo), peat-bog pine (p. uliginosa) and scots pine (p. sylvestris). we set out to investigate three specific speciation scenarios: (i) p. uliginosa is a homoploid hybrid between the other two, (ii) the species have evolved without gene flow after divergence and (iii) there has been su ...201121375633
plant species differences in particulate matter accumulation on leaf surfaces.particulate matter (pm) accumulation on leaves of 22 trees and 25 shrubs was examined in test fields in norway and poland. leaf pm in different particle size fractions (pm(10), pm(2.5), pm(0.2)) differed among the species, by 10- to 15-folds at both test sites. pinus mugo and pinus sylvestris, taxus media and taxus baccata, stephanandra incisa and betula pendula were efficient species in capturing pm. less efficient species were acer platanoides, prunus avium and tilia cordata. differences among ...201222554531
direction of interaction between mountain pine beetle (dendroctonus ponderosae) and resource-sharing wood-boring beetles depends on plant parasite infection.plant pathogens can have cascading consequences on insect herbivores, though whether they alter competition among resource-sharing insect herbivores is unknown. we experimentally tested whether the infection of a plant pathogen, the parasitic plant dwarf mistletoe (arceuthobium americanum), on jack pine (pinus banksiana) altered the competitive interactions among two groups of beetles sharing the same resources: wood-boring beetles (coleoptera: cerambycidae) and the invasive mountain pine beetle ...201626820567
a specialized abc efflux transporter gcabc-g1 confers monoterpene resistance to grosmannia clavigera, a bark beetle-associated fungal pathogen of pine trees.grosmannia clavigera is a bark beetle-vectored pine pathogen in the mountain pine beetle epidemic in western north america. grosmannia clavigera colonizes pines despite the trees' massive oleoresin terpenoid defences. we are using a functional genomics approach to identify g. clavigera's mechanisms of adaptation to pine defences. we annotated the abc transporters in the g. clavigera genome and generated rna-seq transcriptomes from g. clavigera grown with a range of terpenes. we functionally char ...201323252416
the cytochromes p450 of grosmannia clavigera: genome organization, phylogeny, and expression in response to pine host chemicals.grosmannia clavigera is a fungal associate of the mountain pine beetle (dendroctonus ponderosae) and a pathogen of lodgepole pine (pinus contorta) that must overcome terpenoid oleoresin and phenolic defenses of host trees. g. clavigera responds to monoterpene influx with complementary mechanisms that include export and the use of these compounds as a carbon source. cytochromes p450 (cyps) may also be involved in the metabolism of host defense compounds. we have identified and phylogenetically cl ...201323111002
the relative abundance of mountain pine beetle fungal associates through the beetle life cycle in pine trees.the mountain pine beetle (mpb) is a native bark beetle of western north america that attacks pine tree species, particularly lodgepole pine. it is closely associated with the ophiostomatoid ascomycetes grosmannia clavigera, leptographium longiclavatum, ophiostoma montium, and ceratocystiopsis sp.1, with which it is symbiotically associated. to develop a better understanding of interactions between beetles, fungi, and host trees, we used target-specific dna primers with qpcr to assess the changes ...201222735936
Effects of long-term fertilization of forest soils on potential nitrification and on the abundance and community structure of ammonia oxidizers and nitrite oxidizers.Forest fertilization in British Columbia is increasing, to alleviate timber shortfalls resulting from the mountain pine beetle epidemic. However, fertilization effects on soil microbial communities, and consequently ecosystem processes, are poorly understood. Fertilization has contrasting effects on ammonia-oxidizing bacteria and archaea (AOB and AOA) in grassland and agricultural ecosystems, but there are no studies on AOB and AOA in forests. We assessed the effect of periodic (6-yearly applica ...201122066501
responses of dendroctonus brevicomis (coleoptera: curculionidae) in behavioral assays: implications to development of a semiochemical-based tool for tree protection.currently, techniques for managing western pine beetle, dendroctonus brevicomis leconte (coleoptera: curculionidae, scolytinae), infestations are limited to tree removals (thinning) that reduce stand density and presumably host susceptibility, and/or the use of insecticides to protect individual trees. there continues to be significant interest in developing an effective semiochemical-based tool for protecting trees from d. brevicomis attack, largely as an alternative to conventional insecticide ...201222420267
temperature-driven range expansion of an irruptive insect heightened by weakly coevolved plant defenses.warming climate has increased access of native bark beetles to high-elevation pines that historically received only intermittent exposure to these tree-killing herbivores. here we show that a dominant, relatively naïve, high-elevation species, whitebark pine, has inferior defenses against mountain pine beetle compared with its historical lower-elevation host, lodgepole pine. lodgepole pines respond by exuding more resin and accumulating higher concentrations of toxic monoterpenes than whitebark ...201223277541
disentangling detoxification: gene expression analysis of feeding mountain pine beetle illuminates molecular-level host chemical defense detoxification mechanisms.the mountain pine beetle, dendroctonus ponderosae, is a native species of bark beetle (coleoptera: curculionidae) that caused unprecedented damage to the pine forests of british columbia and other parts of western north america and is currently expanding its range into the boreal forests of central and eastern canada and the usa. we conducted a large-scale gene expression analysis (rna-seq) of mountain pine beetle male and female adults either starved or fed in male-female pairs for 24 hours on ...201324223726
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