| altitude trends in conifer leaf morphology and stable carbon isotope composition. | the natural ratio of stable carbon isotopes (δ(13)c) was compared to leaf structural and chemical characteristics in evergreen conifers in the north-central rockies, united states. we sought a general model that would explain variation in δ(13)c across altitudinal gradients. because variation in δ(13)c is attributed to the shifts between supply and demand for carbon dioxide within the leaf, we measured structural and chemical variables related to supply and demand. we measured stomatal density, ... | 2000 | 28308741 |
| autumn stomatal closure in six conifer species of the central rocky mountains. | environmental and water relations parameters during fall were monitored for six conifer tree species common to the central rocky mountains growing naturally at the same location (pinus contorta, pinus ponderosa, pinus flexilus, pseudotsuga menziesii, abies lasiocarpa, picea engelmannii). subsequent to what appeared to be the beginning of seasonal stomatal closure, leaf conductance to water vapor declined sharply following the onset of freezing air temperatures at night. a coincident rapid declin ... | 1984 | 28311019 |
| mountain pine beetle host selection between lodgepole and ponderosa pines in the southern rocky mountains. | recent evidence of range expansion and host transition by mountain pine beetle (dendroctonus ponderosae hopkins; mpb) has suggested that mpb may not primarily breed in their natal host, but will switch hosts to an alternate tree species. as mpb populations expanded in lodgepole pine forests in the southern rocky mountains, we investigated the potential for movement into adjacent ponderosa pine forests. we conducted field and laboratory experiments to evaluate four aspects of mpb population dynam ... | 2016 | 26546596 |
| a novel semiochemical tool for protecting pinus contorta from mortality attributed to dendroctonus ponderosae (coleoptera: curculionidae). | verbenone (4,6,6-trimethylbicyclo[3.1.1]hept-3-en-2-one) is an antiaggregant of the mountain pine beetle, dendroctonus ponderosae hopkins (coleoptera: curculionidae), a notable forest insect capable of causing extensive levels of tree mortality in western north america. several formulations of verbenone are registered for tree protection, but failures in efficacy are not uncommon, particularly when applied during large infestations. a formulation of (-)-verbenone was developed (specialized phero ... | 2015 | 26470118 |
| nonstructural carbohydrate dynamics of lodgepole pine dying from mountain pine beetle attack. | bark beetle outbreaks are an important cause of tree death, but the process by which trees die remains poorly understood. the effect of beetle attack on whole-tree nonstructural carbohydrate (nsc) dynamics is particularly unclear, despite the potential role of carbohydrates in plant defense and survival. we monitored nsc dynamics of all organs in attacked and protected lodgepole pines (pinus contorta) during a mountain pine beetle (dendroctonus ponderosae) outbreak in british columbia, starting ... | 2016 | 26256444 |
| influence of stand structure on carbon-13 of vegetation, soils, and canopy air within deciduous and evergreen forests in utah, united states. | carbon isotope ratios (δ(13)c) were studied in evergreen and deciduous forest ecosystems in semi-arid utah (pinus contorta, populus tremuloides, acer negundo and acer grandidentatum). measurements were taken in four to five stands of each forest ecosystem differing in overstory leaf area index (lai) during two consecutive growing seasons. the δ(13)cleaf (and carbon isotope discrimination) of understory vegetation in the evergreen stands (lai 1.5-2.2) did not differ among canopies with increasing ... | 1997 | 28307459 |
| 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 ... | 2013 | 23679205 |
| recent mountain pine beetle outbreaks, wildfire severity, and postfire tree regeneration in the us northern rockies. | widespread tree mortality caused by outbreaks of native bark beetles (circulionidae: scolytinae) in recent decades has raised concern among scientists and forest managers about whether beetle outbreaks fuel more ecologically severe forest fires and impair postfire resilience. to investigate this question, we collected extensive field data following multiple fires that burned subalpine forests in 2011 throughout the northern rocky mountains across a spectrum of prefire beetle outbreak severity, p ... | 2014 | 25267633 |
| mountain pine beetle infestation of lodgepole pine in areas of water diversion. | the rocky mountains have experienced extensive infestations from the mountain pine beetle (dendroctonus ponderosae hopkins), affecting numerous pine tree species including lodgepole pine (pinus contorta dougl. var. latifolia). water diversions throughout the rocky mountains transport large volumes of water out of the basins of origin, resulting in hydrologic modifications to downstream areas. this study examines the hypothesis that lodgepole pine located below water diversions exhibit an increas ... | 2014 | 24681362 |
| chemical similarity between historical and novel host plants promotes range and host expansion of the mountain pine beetle in a naïve host ecosystem. | host plant secondary chemistry can have cascading impacts on host and range expansion of herbivorous insect populations. we investigated the role of host secondary compounds on pheromone production by the mountain pine beetle (dendroctonus ponderosae) (mpb) and beetle attraction in response to a historical (lodgepole pine, pinus contorta var. latifolia) and a novel (jack pine, pinus banksiana) hosts, as pheromones regulate the host colonization process. beetles emit the same pheromones from both ... | 2014 | 24400902 |
| evaluations of emamectin benzoate and propiconazole for protecting individual pinus contorta from mortality attributed to colonization by dendroctonus ponderosae and associated fungi. | protection of conifers from bark beetle colonization typically involves applications of liquid formulations of contact insecticides to the tree bole. an evaluation was made of the efficacy of bole injections of emamectin benzoate alone and combined with the fungicide propiconazole for protecting individual lodgepole pine, pinus contorta dougl. ex loud., from mortality attributed to colonization by mountain pine beetle, dendroctonus ponderosae hopkins, and progression of associated blue stain fun ... | 2014 | 23868360 |
| 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 ... | 2013 | 23542624 |
| population densities and tree diameter effects associated with verbenone treatments to reduce mountain pine beetle-caused mortality of lodgepole pine. | mountain pine beetle, dendroctonus ponderosae hopkins (coleoptera: curculionidae: scolytinae), is among the primary causes of mature lodgepole pine, pinus contorta variety latifolia mortality. verbenone is the only antiaggregant semiochemical commercially available for reducing mountain pine beetle infestation of lodgepole pine. the success of verbenone treatments has varied greatly in previous studies because of differences in study duration, beetle population size, tree size, or other factors. ... | 2013 | 23448035 |
| spatiotemporal patterns of mountain pine beetle activity in the southern rocky mountains. | the current mountain pine beetle (mpb; dendroctonus ponderosae) outbreak in the southern rocky mountains has impacted approximately 750 000 ha of forest. weather and habitat heterogeneity influence forest insect population dynamics at multiple spatial and temporal scales. comparison of forest insect population dynamics in two principal host species may elucidate the relative contribution of weather and landscape factors in initiating and driving extensive outbreaks. to investigate potential driv ... | 2012 | 23185879 |
| dispersal of warren root collar weevils (coleoptera: curculionidae) in three types of habitat. | warren root collar weevil, hylobius warreni wood, is a native, flightless insect distributed throughout the boreal forest of north america. it is an emerging problem in young plantings of lodgepole pine, pinus contorta variety latifolia, in western canada, where larval feeding can kill young trees by girdling the root collar. susceptible plantings are becoming more abundant following salvage harvesting and replanting activities in the wake of an ongoing epidemic of mountain pine beetle, dendroct ... | 2012 | 22732616 |
| the legacy of attack: implications of high phloem resin monoterpene levels in lodgepole pines following mass attack by mountain pine beetle, dendroctonus ponderosae hopkins. | the mountain pine beetle (dendroctonus ponderosae hopkins) is the most serious pest of pines (pinus) in western north america. host pines protect themselves from attack by producing a complex mixture of terpenes in their resin. we sampled lodgepole pine (pinus contorta variety latifolia) phloem resin at four widely separated locations in the interior of british columbia, canada, both just before (beginning of july) and substantially after (end of august) the mountain pine beetle dispersal period ... | 2012 | 22507014 |
| terpene alcohol pheromone production bydendroctonus ponderosae andips paraconfusus (coleoptera: scolytidae) in the absence of readily culturable microorganisms. | dendroctonus ponderosae hopkins andips paraconfusus lanier of both sexes produced most of their complement of terpene alcohols at normal to elevated levels in the absence of readily culturable microorganisms. however, there was some evidence that microbial involvement may be required by malei. paraconfusus to produce ipsenol and ipsdienol at normal levels. increased levels of certain terpene alcohols found in axenically reared or streptomycin-fed beetles suggest that symbiotic microorganisms may ... | 1989 | 24272090 |
| sex-specific production of ipsdienol and myrcenol bydendroctonus ponderosae (coleoptera: scolytidae) exposed to myrcene vapors. | male mountain pine beetles,dendroctonus ponderosae hopkins, produced ipsdienol [97.0% ± 0.3s-(+)] and myrcenol (90.3% ± 4.0e) when exposed to myrcene vapors. females which were exposed to myrcene vapors did not produce any ipsdienol, but did produce low levels of myrcenol (98.0% ± 0.7e). neither sex produced detectable levels of ipsdienol or myrcenol when fed for 24 hr on lodgepole pine,pinus contorta var.latifolia engelmann. the sex-specific conversion of myrcene to ipsdienol and myrcenol sugge ... | 1986 | 24305835 |
| inheritance of mitochondrial dna in the conifer larix. | restriction fragment length polymorphisms between larix leptolepis and larix decidua were identified in heterologous hybridization experiments, using wheat mitochondrial dna probes specific for atp9, coxi, nad3/rps12, and orf25. analysis of eight individuals of each reciprocal hybrid of these two species revealed that mitochondrial dna was maternally inherited. furthermore, sequences homologous to wheat orf25 were also identified in larix gmelini, larix siberica, larix olgensis, and larix larici ... | 1993 | 24193487 |
| ectomycorrhizal fungi mediate indirect effects of a bark beetle outbreak on secondary chemistry and establishment of pine seedlings. | dendroctonus ponderosae has killed millions of pinus contorta in western north america with subsequent effects on stand conditions, including changes in light intensity, needle deposition, and the composition of fungal community mutualists, namely ectomycorrhizal fungi. it is unknown whether these changes in stand conditions will have cascading consequences for the next generation of pine seedlings. to test for transgenerational cascades on pine seedlings, we tested the effects of fungal inoculu ... | 2015 | 26033270 |
| effects of dwarf mistletoe on stand structure of lodgepole pine forests 21-28 years post-mountain pine beetle epidemic in central oregon. | lodgepole pine (pinus contorta) forests are widely distributed throughout north america and are subject to mountain pine beetle (dendroctonus ponderosae) epidemics, which have caused mortality over millions of hectares of mature trees in recent decades. mountain pine beetle is known to influence stand structure, and has the ability to impact many forest processes. dwarf mistletoe (arceuthobium americanum) also influences stand structure and occurs frequently in post-mountain pine beetle epidemic ... | 2014 | 25221963 |
| a model for mountain pine beetle outbreaks in an age-structured forest: predicting severity and outbreak-recovery cycle period. | the mountain pine beetle (mpb, dendroctonus ponderosae), a tree-killing bark beetle, has historically been part of the normal disturbance regime in lodgepole pine (pinus contorta) forests. in recent years, warm winters and summers have allowed mpb populations to achieve synchronous emergence and successful attacks, resulting in widespread population outbreaks and resultant tree mortality across western north america. we develop an age-structured forest demographic model that incorporates tempera ... | 2015 | 25976694 |
| rapid increases in forest understory diversity and productivity following a mountain pine beetle (dendroctonus ponderosae) outbreak in pine forests. | the current unprecedented outbreak of mountain pine beetle (dendroctonus ponderosae) in lodgepole pine (pinus contorta) forests of western canada has resulted in a landscape consisting of a mosaic of forest stands at different stages of mortality. within forest stands, understory communities are the reservoir of the majority of plant species diversity and influence the composition of future forests in response to disturbance. although changes to stand composition following beetle outbreaks are w ... | 2015 | 25859663 |
| proteomics indicators of the rapidly shifting physiology from whole mountain pine beetle, dendroctonus ponderosae (coleoptera: curculionidae), adults during early host colonization. | we developed proteome profiles for host colonizing mountain pine beetle adults, dendroctonus ponderosae hopkins (coleoptera: curculionidae). adult insects were fed in pairs on fresh host lodgepole pine, pinus contorta dougl. ex loud, phloem tissue. the proteomes of fed individuals were monitored using itraq and compared to those of starved beetles, revealing 757 and 739 expressed proteins in females and males, respectively, for which quantitative information was obtained. overall functional cate ... | 2014 | 25360753 |