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Sample records for dendroctonus ponderosae electronic

  1. Cryptic postzygotic isolation in an eruptive species of bark beetle (Dendroctonus ponderosae)

    Science.gov (United States)

    Ryan R. Bracewell; Michael E. Pfrender; Karen E. Mock; Barbara J. Bentz

    2011-01-01

    Studies of postzygotic isolation often involve well-differentiated taxa that show a consistent level of incompatibility, thereby limiting our understanding of the initial stages and development of reproductive barriers. Dendroctonus ponderosae provides an informative system because recent evidence suggests that distant populations produce hybrids with reproductive...

  2. Genetic architecture of differences in fitness traits among geographically separated Dendroctonus ponderosae populations

    Science.gov (United States)

    Barbara Bentz; Mike Pfrender; Ryan Bracewell; Karen Mock

    2007-01-01

    The mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae, Scolytinae) (MPB), is widely distributed across western North America spanning 25 degrees latitude and more than 2,500 m elevation. In a common garden experiment, Bentz and others (2001) observed that MPB populations from a southern location required significantly...

  3. Phenology and density-dependent dispersal predict patterns of mountain pine beetle (Dendroctonus ponderosae) impact

    Science.gov (United States)

    James A. Powell; Barbara J. Bentz

    2014-01-01

    For species with irruptive population behavior, dispersal is an important component of outbreak dynamics. We developed and parameterized a mechanistic model describing mountain pine beetle (Dendroctonus ponderosae Hopkins) population demographics and dispersal across a landscape. Model components include temperature-dependent phenology, host tree colonization...

  4. Ergosterol Content of Fungi Associated with Dendroctonus ponderosae and Dendroctonus rufipennis (Coleoptera: Curculionidae, Scolytinae)

    National Research Council Canada - National Science Library

    Barbara J. Bentz; Diana L. Six

    2006-01-01

    .... For phloephagous species, such as Dendroctonus bark beetles, whose food does not necessarily contain appropriate types or adequate quantities of sterols, fungal symbionts may provide an alternative...

  5. Ergosterol content of fungi associated with Dendroctonus ponderosae and Dendroctonus rufipennis (Coleoptera: Curculionidae, Scolytinae)

    Science.gov (United States)

    Barbara J. Bentz; Diana L. Six

    2006-01-01

    Insects require sterols for normal growth, metamorphosis, and reproduction, yet they are unable to synthesize these organic compounds and are therefore dependent upon a dietary source. For phloephagous species, such as Dendroctonus bark beetles, whose food does not necessarily contain appropriate types or adequate quantities of sterols, fungal...

  6. Laboratory assays of select candidate insecticides for control of Dendroctonus ponderosae.

    Science.gov (United States)

    Fettig, Christopher J; Hayes, Christopher J; McKelvey, Stephen R; Mori, Sylvia R

    2011-05-01

    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 insecticides, cyantraniliprole [Cyazypyr(™)-OD (oil dispersion) and Cyazypyr(™)-SC (suspension concentrate)] and chlorantraniliprole (Rynaxypyr(®)), and carbaryl were assayed in both filter paper and topical assays. Compared with 20,000 mg L(-1) carbaryl (i.e. the maximum label rate for solutions applied to conifers for protection from bark beetle attack in the western United States), cyantraniliprole OD caused similar rates of mortality in D. ponderosae adults at 400-fold weaker concentrations in both bioassays, while cyantraniliprole SC caused similar rates of mortality at 40-fold weaker concentrations. Probit analyses confirmed that D. ponderosae is most sensitive to cyantraniliprole OD, while chlorantraniliprole was effective at concentrations similar to carbaryl. These results suggest that lower concentrations of carbaryl have merit for field testing than have been previously considered. While cyantraniliprole and chlorantraniliprole have similar modes of action, cyantraniliprole OD appears to have greater promise for protecting individual trees from mortality attributed to D. ponderosae attack and should be evaluated in field studies. This article is a US Government work and is in the public domain in the USA. Published 2011 by John Wiley & Sons, Ltd.

  7. Cryptic postzygotic isolation in an eruptive species of bark beetle (Dendroctonus ponderosae).

    Science.gov (United States)

    Bracewell, Ryan R; Pfrender, Michael E; Mock, Karen E; Bentz, Barbara J

    2011-04-01

    Studies of postzygotic isolation often involve well-differentiated taxa that show a consistent level of incompatibility, thereby limiting our understanding of the initial stages and development of reproductive barriers. Dendroctonus ponderosae provides an informative system because recent evidence suggests that distant populations produce hybrids with reproductive incompatibilities. Dendroctonus ponderosae shows an isolation-by-distance gene flow pattern allowing us to characterize the evolution of postzygotic isolation (e.g., hybrid inviability, hybrid sterility) by crossing populations along a continuum of geographic/genetic divergence. We found little evidence of hybrid inviability among these crosses. However, crosses between geographically distant populations produced sterile males (consistent with Haldane's rule). This effect was not consistent with the fixation of mutations in an isolation-by-distance pattern, but instead is spatially localized. These reproductive barriers are uncorrelated with a reduction in gene flow suggesting their recent development. Crosses between geographically proximal populations bounding the transition from compatibility to hybrid male sterility showed evidence of unidirectional reduction in hybrid male fecundity. Our study describes significant postzygotic isolation occurring across a narrow and molecularly cryptic geographic zone between the states of Oregon and Idaho. This study provides a view of the early stages of postzygotic isolation in a geographically widespread species. © 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.

  8. A Novel Semiochemical Tool for Protecting Pinus contorta From Mortality Attributed to Dendroctonus ponderosae (Coleoptera: Curculionidae).

    Science.gov (United States)

    Fettig, Christopher J; Munson, A Steven; Reinke, Michael; Mafra-Neto, Agenor

    2015-02-01

    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 Pheromone & Lure Application Technology [SPLAT] Verb, ISCA Technologies Inc., Riverside, CA) and evaluated for protecting individual lodgepole pine, Pinus contorta Douglas ex Loudon, and small stands of P. contorta from mortality attributed to D. ponderosae. SPLAT Verb applied to individual P. contorta resulted in complete tree protection, while 93.3% mortality occurred in the untreated controls. Significantly fewer P. contorta were killed by D. ponderosae within 0.041-ha circular plots surrounding P. contorta treated with SPLAT Verb compared with the untreated control. In a second study, a smaller percentage of P. contorta were colonized and killed on 0.4-ha square plots treated with SPLAT Verb compared with the untreated control. No significant differences in levels of tree mortality were observed between the untreated control and another formulation of verbenone (7-g pouch) or between the 7-g pouch and SPLAT Verb. In a trapping bioassay, no significant differences were observed among captures in multiple-funnel traps at 1, 2, or 4 m from the point of release of SPLAT Verb. Significantly fewer D. ponderosae were collected at 1 and 2 m compared with 8 m. Significantly more D. ponderosae were captured at the farthest distance evaluated (16 m) than at any other distance. Our data indicate that SPLAT Verb is effective for protecting individual P. contorta and small stands of P. contorta from mortality attributed to D. ponderosae at moderate doses. The high levels of tree

  9. exo-Brevicomin biosynthetic pathway enzymes from the Mountain Pine Beetle, Dendroctonus ponderosae.

    Science.gov (United States)

    Song, Minmin; Delaplain, Patrick; Nguyen, Trang T; Liu, Xibei; Wickenberg, Leah; Jeffrey, Christopher; Blomquist, Gary J; Tittiger, Claus

    2014-10-01

    exoBrevicomin (exo-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane) is an important semiochemical for a number of beetle species, including the highly destructive Mountain Pine Beetle (Dendroctonus ponderosae). It is also found in other insects and the African elephant. Despite its significance, very little is known about its biosynthesis. A recent microarray analysis implicated a small cluster of three D. ponderosae genes in exo-brevicomin biosynthesis, two of which had identifiable open reading frames (Aw et al., 2010; BMC Genomics 11:215). Here we report further expression profiling of two genes in that cluster and functional analysis of their recombinantly-produced enzymes. One encodes a short-chain dehydrogenase that used NAD(P)(+) as a co-factor to catalyze the oxidation of (Z)-6-nonen-2-ol to (Z)-6-nonen-2-one. We therefore named the enzyme (Z)-6-nonen-2-ol dehydrogenase (ZnoDH). The other encodes the cytochrome P450, CYP6CR1, which epoxidized (Z)-6-nonen-2-one to 6,7-epoxynonan-2-one with very high specificity and substrate selectivity. Both the substrates and products of the two enzymes are intermediates in the exo-brevicomin biosynthetic pathway. Thus, ZnoDH and CYP6CR1 are enzymes that apparently catalyze the antepenultimate and penultimate steps in the exo-brevicomin biosynthetic pathway, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. exo-Brevicomin biosynthesis in the fat body of the mountain pine beetle, Dendroctonus ponderosae.

    Science.gov (United States)

    Song, Minmin; Gorzalski, Andrew; Nguyen, Trang T; Liu, Xibei; Jeffrey, Christopher; Blomquist, Gary J; Tittiger, Claus

    2014-02-01

    exo-Brevicomin (exo-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane) is an important semiochemical for a number of beetle species, including the highly destructive mountain pine beetle, Dendroctonus ponderosae. It also has been found in other insects and even in the African elephant. Despite its significance, little is known about its biosynthesis. In order to fill this gap and to identify new molecular targets for potential pest management methods, we performed gas chromatography-mass spectrometry analyses of cell cultures and in vitro assays of various D. ponderosae tissues with exo-brevicomin intermediates, analogs, and inhibitors. We confirmed that exo-brevicomin was synthesized by "unfed" males after emerging from the brood tree. Furthermore, in contrast to the paradigm established for biosynthesis of monoterpenoid pheromone components in bark beetles, exo-brevicomin was produced in the fat body, and not in the anterior midgut. The first committed step involves decarboxylation or decarbonylation of ω-3-decenoic acid, which is derived from a longer-chain precursor via β-oxidation, to (Z)-6-nonen-2-ol. This secondary alcohol is converted to the known precursor, (Z)-6-nonen-2-one, and further epoxidized by a cytochrome P450 to 6,7-epoxynonan-2-one. The keto-epoxide is stable at physiological pH, suggesting that its final cyclization to form exo-brevicomin is enzyme-catalyzed. exo-Brevicomin production is unusual in that tissue not derived from ectoderm apparently is involved.

  11. Metabolism and cold tolerance of overwintering adult mountain pine beetles (Dendroctonus ponderosae): evidence of facultative diapause?

    Science.gov (United States)

    Lester, Jack D; Irwin, Jason T

    2012-06-01

    We sought evidence for a distinct diapause in adult overwintering mountain pine beetles (Dendroctonus ponderosae Hopkins) by measuring metabolic rate and supercooling ability of field collected beetles throughout the year. Metabolic rates measured at 0, 5, and 10°C declined significantly from October through November, then rose slowly, reaching levels as high as those recorded in October by late May. From December to February metabolic rates were not correlated with minimum weekly phloem temperatures (R(2)=0.0%, P=0.592), but were correlated with phloem temperatures as winter advanced to spring (R(2)=44.8%, P=0.010), a pattern consistent with progression through the maintenance and termination phases of diapause. Supercooling points were also significantly lower in winter compared to fall and spring (F((8,143))=32.6, P79% for all three temperatures). Dry mass declined linearly with winter progression (F((8,150))=8.34, P<0.001), explained by catabolism of metabolic reserves, with a concomitant accumulation of metabolic water (F((8,147))=35.24, P<0.001). The strong mid-winter metabolic suppression correlated with improved supercooling ability, coupled with their lack of response to variation in environmental temperature, are evidence of possible diapause in adult overwintering mountain pine beetles. Copyright © 2012. Published by Elsevier Ltd.

  12. Draft genome of the mountain pine beetle, Dendroctonus ponderosae Hopkins, a major forest pest.

    Science.gov (United States)

    Keeling, Christopher I; Yuen, Macaire M S; Liao, Nancy Y; Docking, T Roderick; Chan, Simon K; Taylor, Greg A; Palmquist, Diana L; Jackman, Shaun D; Nguyen, Anh; Li, Maria; Henderson, Hannah; Janes, Jasmine K; Zhao, Yongjun; Pandoh, Pawan; Moore, Richard; Sperling, Felix A H; Huber, Dezene P W; Birol, Inanc; Jones, Steven J M; Bohlmann, Joerg

    2013-03-27

    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. We developed a genome sequence resource for the mountain pine beetle to better understand the unique aspects of this insect's biology. A draft de novo genome sequence was assembled from paired-end, short-read sequences from an individual field-collected male pupa, and scaffolded using mate-paired, short-read genomic sequences from pooled field-collected pupae, paired-end short-insert whole-transcriptome shotgun sequencing reads of mRNA from adult beetle tissues, and paired-end Sanger EST sequences from various life stages. We describe the cytochrome P450, glutathione S-transferase, and plant cell wall-degrading enzyme gene families important to the survival of the mountain pine beetle in its harsh and nutrient-poor host environment, and examine genome-wide single-nucleotide polymorphism variation. A horizontally transferred bacterial sucrose-6-phosphate hydrolase was evident in the genome, and its tissue-specific transcription suggests a functional role for this beetle. Despite Coleoptera being the largest insect order with over 400,000 described species, including many agricultural and forest pest species, this is only the second genome sequence reported in Coleoptera, and will provide an important resource for the Curculionoidea and other insects.

  13. How the mountain pine beetle (Dendroctonus ponderosae) breached the Canadian Rocky Mountains.

    Science.gov (United States)

    Janes, Jasmine K; Li, Yisu; Keeling, Christopher I; Yuen, Macaire M S; Boone, Celia K; Cooke, Janice E K; Bohlmann, Joerg; Huber, Dezene P W; Murray, Brent W; Coltman, David W; Sperling, Felix A H

    2014-07-01

    The mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins), a major pine forest pest native to western North America, has extended its range north and eastward during an ongoing outbreak. Determining how the MPB has expanded its range to breach putative barriers, whether physical (nonforested prairie and high elevation of the Rocky Mountains) or climatic (extreme continental climate where temperatures can be below -40 °C), may contribute to our general understanding of range changes as well as management of the current epidemic. Here, we use a panel of 1,536 single nucleotide polymorphisms (SNPs) to assess population genetic structure, connectivity, and signals of selection within this MPB range expansion. Biallelic SNPs in MPB from southwestern Canada revealed higher genetic differentiation and lower genetic connectivity than in the northern part of its range. A total of 208 unique SNPs were identified using different outlier detection tests, of which 32 returned annotations for products with putative functions in cholesterol synthesis, actin filament contraction, and membrane transport. We suggest that MPB has been able to spread beyond its previous range by adjusting its cellular and metabolic functions, with genome scale differentiation enabling populations to better withstand cooler climates and facilitate longer dispersal distances. Our study is the first to assess landscape-wide selective adaptation in an insect. We have shown that interrogation of genomic resources can identify shifts in genetic diversity and putative adaptive signals in this forest pest species. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  14. Functional genomics of mountain pine beetle (Dendroctonus ponderosae midguts and fat bodies

    Directory of Open Access Journals (Sweden)

    Bearfield Jeremy C

    2010-03-01

    Full Text Available Abstract Background The mountain pine beetle (Dendroctonus ponderosae is a significant coniferous forest pest in western North America. It relies on aggregation pheromones to colonize hosts. Its three major pheromone components, trans-verbenol, exo-brevicomin, and frontalin, are thought to arise via different metabolic pathways, but the enzymes involved have not been identified or characterized. We produced ESTs from male and female midguts and associated fat bodies and used custom oligonucleotide microarrays to study gene expression patterns and thereby made preliminary identification of pheromone-biosynthetic genes. Results Clones from two un-normalized cDNA libraries were directionally sequenced from the 5' end to yield 11,775 ESTs following sequence cleansing. The average read length was 550 nt. The ESTs clustered into 1,201 contigs and 2,833 singlets (4,034 tentative unique genes. The ESTs are broadly distributed among GO functional groups, suggesting they reflect a broad spectrum of the transcriptome. Among the most represented genes are representatives of sugar-digesting enzymes and members of an apparently Scolytid-specific gene family of unknown function. Custom NimbleGen 4-plex arrays representing the 4,034 tentative unique genes were queried with RNA from eleven different biological states representing larvae, pupae, and midguts and associated fat bodies of unfed or fed adults. Quantitative (Real-Time RT-PCR (qRT-PCR experiments confirmed that the microarray data accurately reflect expression levels in the different samples. Candidate genes encoding enzymes involved in terminal steps of biosynthetic pathways for exo-brevicomin and frontalin were tentatively identified. Conclusions These EST and microarray data are the first publicly-available functional genomics resources for this devastating forestry pest.

  15. The resin composition of ponderosa pine (Pinus ponderosa) attacked by the roundheaded pine beetle (Dendroctonus adjunctus) (Coleoptera: Curculionidae, Scolytinae)

    Science.gov (United States)

    Melissa J. Fischer; Kristen M. Waring; Richard W. Hofstetter; Thomas E. Kolb

    2008-01-01

    Dendroctonus adjunctus is an aggressive bark beetle species that attacks several species of pine throughout its range from southern Utah and Colorado south to Guatemala. A current outbreak of D. adjunctus provided a unique opportunity to study the relationship between this beetle and pine resin chemistry in northern Arizona. We...

  16. Seasonal shifts in accumulation of glycerol biosynthetic gene transcripts in mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae, larvae

    Directory of Open Access Journals (Sweden)

    Jordie D. Fraser

    2017-06-01

    Full Text Available Winter mortality is a major factor regulating population size of the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae. Glycerol is the major cryoprotectant in this freeze intolerant insect. We report findings from a gene expression study on an overwintering mountain pine beetle population over the course of 35 weeks. mRNA transcript levels suggest glycerol production in the mountain pine beetle occurs through glycogenolytic, gluconeogenic and potentially glyceroneogenic pathways, but not from metabolism of lipids. A two-week lag period between fall glycogen phosphorylase transcript and phosphoenolpyruvate carboxykinase transcript up-regulation suggests that gluconeogenesis serves as a secondary glycerol-production process, subsequent to exhaustion of the primary glycogenolytic source. These results provide a first look at the details of seasonal gene expression related to the production of glycerol in the mountain pine beetle.

  17. Seasonal shifts in accumulation of glycerol biosynthetic gene transcripts in mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae), larvae.

    Science.gov (United States)

    Fraser, Jordie D; Bonnett, Tiffany R; Keeling, Christopher I; Huber, Dezene P W

    2017-01-01

    Winter mortality is a major factor regulating population size of the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae). Glycerol is the major cryoprotectant in this freeze intolerant insect. We report findings from a gene expression study on an overwintering mountain pine beetle population over the course of 35 weeks. mRNA transcript levels suggest glycerol production in the mountain pine beetle occurs through glycogenolytic, gluconeogenic and potentially glyceroneogenic pathways, but not from metabolism of lipids. A two-week lag period between fall glycogen phosphorylase transcript and phosphoenolpyruvate carboxykinase transcript up-regulation suggests that gluconeogenesis serves as a secondary glycerol-production process, subsequent to exhaustion of the primary glycogenolytic source. These results provide a first look at the details of seasonal gene expression related to the production of glycerol in the mountain pine beetle.

  18. Frontalin pheromone biosynthesis in the mountain pine beetle, Dendroctonus ponderosae, and the role of isoprenyl diphosphate synthases.

    Science.gov (United States)

    Keeling, Christopher I; Chiu, Christine C; Aw, Tidiane; Li, Maria; Henderson, Hannah; Tittiger, Claus; Weng, Hong-Biao; Blomquist, Gary J; Bohlmann, Joerg

    2013-11-19

    The mountain pine beetle (Dendroctonus ponderosae Hopkins) is the most destructive pest of western North American pine forests. Adult males produce frontalin, an eight-carbon antiaggregation pheromone, via the mevalonate pathway, as part of several pheromones that initiate and modulate the mass attack of host trees. Frontalin acts as a pheromone, attractant, or kairomone in most Dendroctonus species, other insects, and even elephants. 6-Methylhept-6-en-2-one, a frontalin precursor, is hypothesized to originate from 10-carbon geranyl diphosphate (GPP), 15-carbon farnesyl diphosphate (FPP), or 20-carbon geranylgeranyl diphosphate (GGPP) via a dioxygenase- or cytochrome P450-mediated carbon-carbon bond cleavage. To investigate the role of isoprenyl diphosphate synthases in pheromone biosynthesis, we characterized a bifunctional GPP/FPP synthase and a GGPP synthase in the mountain pine beetle. The ratio of GPP to FPP produced by the GPP/FPP synthase was highly dependent on the ratio of the substrates isopentenyl diphosphate and dimethylallyl diphosphate used in the assay. Transcript levels in various tissues and life stages suggested that GGPP rather than GPP or FPP is used as a precursor to frontalin. Reduction of transcript levels by RNA interference of the isoprenyl diphosphate synthases identified GGPP synthase as having the largest effect on frontalin production, suggesting that frontalin is derived from a 20-carbon isoprenoid precursor rather than from the 10- or 15-carbon precursors.

  19. Rapid Increases in forest understory diversity and productivity following a mountain pine beetle (Dendroctonus ponderosae) outbreak in pine forests.

    Science.gov (United States)

    Pec, Gregory J; Karst, Justine; Sywenky, Alexandra N; Cigan, Paul W; Erbilgin, Nadir; Simard, Suzanne W; Cahill, James F

    2015-01-01

    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 well documented, information on immediate responses of forest understory plant communities is limited. The objective of this study was to examine the effects of D. ponderosae-induced tree mortality on initial changes in diversity and productivity of understory plant communities. We established a total of 110 1-m2 plots across eleven mature lodgepole pine forests to measure changes in understory diversity and productivity as a function of tree mortality and below ground resource availability across multiple years. Overall, understory community diversity and productivity increased across the gradient of increased tree mortality. Richness of herbaceous perennials increased with tree mortality as well as soil moisture and nutrient levels. In contrast, the diversity of woody perennials did not change across the gradient of tree mortality. Understory vegetation, namely herbaceous perennials, showed an immediate response to improved growing conditions caused by increases in tree mortality. How this increased pulse in understory richness and productivity affects future forest trajectories in a novel system is unknown.

  20. Rapid Increases in forest understory diversity and productivity following a mountain pine beetle (Dendroctonus ponderosae outbreak in pine forests.

    Directory of Open Access Journals (Sweden)

    Gregory J Pec

    Full Text Available 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 well documented, information on immediate responses of forest understory plant communities is limited. The objective of this study was to examine the effects of D. ponderosae-induced tree mortality on initial changes in diversity and productivity of understory plant communities. We established a total of 110 1-m2 plots across eleven mature lodgepole pine forests to measure changes in understory diversity and productivity as a function of tree mortality and below ground resource availability across multiple years. Overall, understory community diversity and productivity increased across the gradient of increased tree mortality. Richness of herbaceous perennials increased with tree mortality as well as soil moisture and nutrient levels. In contrast, the diversity of woody perennials did not change across the gradient of tree mortality. Understory vegetation, namely herbaceous perennials, showed an immediate response to improved growing conditions caused by increases in tree mortality. How this increased pulse in understory richness and productivity affects future forest trajectories in a novel system is unknown.

  1. A suitability analysis of Dendroctonus ponderosae in China%中欧山松大小蠹在中国的适生性分析

    Institute of Scientific and Technical Information of China (English)

    杜宇; 姚剑; 李生贵; 马平; 蒋小龙

    2011-01-01

    Dendroctonus ponderosae Hopkins is one of the most important pests causing considerable economic losses of Pinus in America.Based on global distribution of D.ponderosae and global climate data, its potential suitable distribution in China was predicted by using BIOCLIM ecological niche modeling and ArcGIS.The results indicated that the optimum establishment areas were most areas of northern and northeastern China and parts of southwestern China.The predicted potential distribution of D.ponderosae in China was illustrated by ArcGIS.%中欧山松大小蠹(Dendroctonus ponderosae Hopkins)是严重危害松类针叶树种的蛀干害虫.本文基于气象数据,利用BIOCLIM生态位模型对中欧山松大小蠹在我国的适生区进行了分析,结果显示该小蠹能广泛分布在华北、东北的大部分地区和西南的部分地区,提供了ArcGIS适生区预测分布图.

  2. Toxicity of Monoterpene Structure, Diversity and Concentration to Mountain Pine Beetles, Dendroctonus ponderosae: Beetle Traits Matter More.

    Science.gov (United States)

    Reid, Mary L; Sekhon, Jagdeep K; LaFramboise, Lanielle M

    2017-03-03

    A high diversity of plant defenses may be a response to herbivore diversity or may be collectively more toxic than single compounds, either of which may be important for understanding insect-plant associations. Monoterpenes in conifers are particularly diverse. We tested the fumigant toxicity of four monoterpenes, alone and in combination, to mountain pine beetles, Dendroctonus ponderosae, in the context of the beetles' individual body traits. Chemical structures of tested monoterpene hydrocarbons had modest effects on beetle survival, mass loss, water content and fat content, with (R)-(+)-limonene tending to be more toxic than (-)-α-pinene, (-)-β-pinene, and (+)-3-carene. Monoterpene diversity (all qualitative combinations of one to four monoterpenes) did not affect toxicity. Concentration (0 to 1200 ppm) of individual monoterpenes was a strong determinant of toxicity. Beetle body size and body condition index strongly and positively affected survival during monoterpene treatments. Larger beetles in better condition lost proportionally less mass during exposure, where proportion mass loss negatively affected survivorship. Toxicity was much more associated with water loss than with fat loss, suggesting that a main cost of detoxification is excretion, a process that has received little attention. These results provide insight into the determinants of beetle success in historic and novel hosts that differ in monoterpene composition and concentration. We also suggest that water availability will affect beetle success directly through their ability to tolerate detoxification as well as indirectly through host responses to drought.

  3. Global and comparative proteomic profiling of overwintering and developing mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Curculionidae), larvae.

    Science.gov (United States)

    Bonnett, Tiffany R; Robert, Jeanne A; Pitt, Caitlin; Fraser, Jordie D; Keeling, Christopher I; Bohlmann, Jörg; Huber, Dezene P W

    2012-12-01

    Mountain pine beetles, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae), are native to western North America, but have recently begun to expand their range across the Canadian Rocky Mountains. The requirement for larvae to withstand extremely cold winter temperatures and potentially toxic host secondary metabolites in the midst of their ongoing development makes this a critical period of their lives. We have uncovered global protein profiles for overwintering mountain pine beetle larvae. We have also quantitatively compared the proteomes for overwintering larvae sampled during autumn cooling and spring warming using iTRAQ methods. We identified 1507 unique proteins across all samples. In total, 33 proteins exhibited differential expression (FDR < 0.05) when compared between larvae before and after a cold snap in the autumn; and 473 proteins exhibited differential expression in the spring when measured before and after a steady incline in mean daily temperature. Eighteen proteins showed significant changes in both autumn and spring samples. These first proteomic data for mountain pine beetle larvae show evidence of the involvement of trehalose, 2-deoxyglucose, and antioxidant enzymes in overwintering physiology; confirm and expand upon previous work implicating glycerol in cold tolerance in this insect; and provide new, detailed information on developmental processes in beetles. These results and associated data will be an invaluable resource for future targeted research on cold tolerance mechanisms in the mountain pine beetle and developmental biology in coleopterans. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Efficacy of "Verbenone Plus" for protecting ponderosa pine trees and stands from Dendroctonus brevicomis (Coleoptera: Curculionidae) attack in British Columbia and California.

    Science.gov (United States)

    Fettig, Christopher J; McKelvey, Stephen R; Dabney, Christopher P; Huber, Dezene P W; Lait, Cameron G; Fowler, Donald L; Borden, John H

    2012-10-01

    The western pine beetle, Dendroctonus brevicomis LeConte (Coleoptera: Curculionidae, Scolytinae), is a major cause of ponderosa pine, Pinus ponderosa Douglas ex Lawson, mortality in much of western North America. We review several years of research that led to the identification of Verbenone Plus, a novel four-component semiochemcial blend [acetophenone, (E)-2-hexen-1-ol + (Z)-2-hexen-1-ol, and (-)-verbenone] that inhibits the response of D. brevicomis to attractant-baited traps, and examine the efficacy of Verbenone Plus for protecting individual trees and forest stands from D. brevicomis infestations in British Columbia and California. In all experiments, semiochemicals were stapled around the bole of treated trees at approximately equal to 2 m in height. (-)-Verbenone alone had no effect on the density of total attacks and successful attacks by D. brevicomis on attractant-baited P. ponderosa, but significantly increased the percentage of pitchouts (unsuccessful D. brevicomis attacks). Verbenone Plus significantly reduced the density of D. brevicomis total attacks and D. brevicomis successful attacks on individual trees. A significantly higher percentage of pitchouts occurred on Verbenone Plus-treated trees. The application of Verbenone Plus to attractant-baited P. ponderosa significantly reduced levels of tree mortality. In stand protection studies, Verbenone Plus significantly reduced the percentage of trees mass attacked by D. brevicomis in one study, but in a second study no significant treatment effect was observed. Future research should concentrate on determining optimal release rates and spacings of release devices in stand protection studies, and expansion of Verbenone Plus into other systems where verbenone alone has not provided adequate levels of tree protection.

  5. Evaluations of emamectin benzoate and propiconazole for protecting individual Pinus contorta from mortality attributed to colonization by Dendroctonus ponderosae and associated fungi.

    Science.gov (United States)

    Fettig, Christopher J; Munson, A Steven; Grosman, Donald M; Bush, Parshall B

    2014-05-01

    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 fungi. Injections of emamectin benzoate applied in mid-June did not provide adequate levels of tree protection; however, injections of emamectin benzoate + propiconazole applied at the same time were effective for two field seasons. Injections of emamectin benzoate and emamectin benzoate + propiconazole in mid-September provided tree protection the following field season, but unfortunately efficacy could not be determined during a second field season owing to insufficient levels of tree mortality observed in the untreated control, indicative of low D. ponderosae populations. Previous evaluations of emamectin benzoate for protecting P. contorta from mortality attributed to D. ponderosae have failed to demonstrate efficacy, which was later attributed to inadequate distribution of emamectin benzoate following injections applied several weeks before D. ponderosae colonization. The present data indicate that injections of emamectin benzoate applied in late summer or early fall will provide adequate levels of tree protection the following summer, and that, when emamectin benzoate is combined with propiconazole, tree protection is afforded the year that injections are implemented. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  6. The resin composition of ponderosa pine (Pinus ponderosa) attacked by the roundheaded pine beetle (Dendroctonus adjunctus) (Coleoptera: Curculionidae, Scolytinae) (P-53)

    Science.gov (United States)

    Melissa J. Fischer; Kristen M. Waring; Richard W. Hofstetter; Thomas E. Kolb

    2008-01-01

    Dendroctonus adjunctus is an aggressive bark beetle species that attacks several species of pine throughout its range from southern Utah and Colorado south to Guatemala. A current outbreak of D. adjunctus provided a unique opportunity to study the relationship between this beetle and pine resin chemistry in northern Arizona. We compared the resin composition of trees...

  7. Transcriptome and full-length cDNA resources for the mountain pine beetle, Dendroctonus ponderosae Hopkins, a major insect pest of pine forests.

    Science.gov (United States)

    Keeling, Christopher I; Henderson, Hannah; Li, Maria; Yuen, Mack; Clark, Erin L; Fraser, Jordie D; Huber, Dezene P W; Liao, Nancy Y; Docking, T Roderick; Birol, Inanc; Chan, Simon K; Taylor, Greg A; Palmquist, Diana; Jones, Steven J M; Bohlmann, Joerg

    2012-08-01

    Bark beetles (Coleoptera: Curculionidae: Scolytinae) are major insect pests of many woody plants around the world. The mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, is a significant historical pest of western North American pine forests. It is currently devastating pine forests in western North America--particularly in British Columbia, Canada--and is beginning to expand its host range eastward into the Canadian boreal forest, which extends to the Atlantic coast of North America. Limited genomic resources are available for this and other bark beetle pests, restricting the use of genomics-based information to help monitor, predict, and manage the spread of these insects. To overcome these limitations, we generated comprehensive transcriptome resources from fourteen full-length enriched cDNA libraries through paired-end Sanger sequencing of 100,000 cDNA clones, and single-end Roche 454 pyrosequencing of three of these cDNA libraries. Hybrid de novo assembly of the 3.4 million sequences resulted in 20,571 isotigs in 14,410 isogroups and 246,848 singletons. In addition, over 2300 non-redundant full-length cDNA clones putatively containing complete open reading frames, including 47 cytochrome P450s, were sequenced fully to high quality. This first large-scale genomics resource for bark beetles provides the relevant sequence information for gene discovery; functional and population genomics; comparative analyses; and for future efforts to annotate the MPB genome. These resources permit the study of this beetle at the molecular level and will inform research in other Dendroctonus spp. and more generally in the Curculionidae and other Coleoptera. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Antennal transcriptome analysis of the chemosensory gene families in the tree killing bark beetles, Ips typographus and Dendroctonus ponderosae (Coleoptera: Curculionidae: Scolytinae).

    Science.gov (United States)

    Andersson, Martin N; Grosse-Wilde, Ewald; Keeling, Christopher I; Bengtsson, Jonas M; Yuen, Macaire M S; Li, Maria; Hillbur, Ylva; Bohlmann, Jörg; Hansson, Bill S; Schlyter, Fredrik

    2013-03-21

    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 olfactory detection has been lacking in bark beetles and is limited in Coleoptera. We assembled antennal transcriptomes from next-generation sequencing of I. typographus and D. ponderosae to identify members of the major chemosensory multi-gene families. Gene ontology (GO) annotation indicated that the relative abundance of transcripts associated with specific GO terms was highly similar in the two species. Transcripts with terms related to olfactory function were found in both species. Focusing on the chemosensory gene families, we identified 15 putative odorant binding proteins (OBP), 6 chemosensory proteins (CSP), 3 sensory neuron membrane proteins (SNMP), 43 odorant receptors (OR), 6 gustatory receptors (GR), and 7 ionotropic receptors (IR) in I. typographus; and 31 putative OBPs, 11 CSPs, 3 SNMPs, 49 ORs, 2 GRs, and 15 IRs in D. ponderosae. Predicted protein sequences were compared with counterparts in the flour beetle, Tribolium castaneum, the cerambycid beetle, Megacyllene caryae, and the fruit fly, Drosophila melanogaster. The most notable result was found among the ORs, for which large bark beetle-specific expansions were found. However, some clades contained receptors from all four beetle species, indicating a degree of conservation among some coleopteran OR lineages. Putative GRs for carbon dioxide and orthologues for the conserved antennal IRs were included in the identified receptor sets. The protein families important for chemoreception have now been identified in

  9. Direction of interaction between mountain pine beetle (Dendroctonus ponderosae) and resource-sharing wood-boring beetles depends on plant parasite infection.

    Science.gov (United States)

    Klutsch, Jennifer G; Najar, Ahmed; Cale, Jonathan A; Erbilgin, Nadir

    2016-09-01

    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 (Dendroctonus ponderosae) (Coleoptera: Curculionidae). We were particularly interested in identifying potential mechanisms governing the direction of interactions (from competition to facilitation) between the two beetle groups. At the lowest and highest disease severity, wood-boring beetles increased their consumption rate relative to feeding levels at moderate severity. The performance (brood production and feeding) of mountain pine beetle was negatively associated with wood-boring beetle feeding and disease severity when they were reared separately. However, when both wood-boring beetles and high severity of plant pathogen infection occurred together, mountain pine beetle escaped from competition and improved its performance (increased brood production and feeding). Species-specific responses to changes in tree defense compounds and quality of resources (available phloem) were likely mechanisms driving this change of interactions between the two beetle groups. This is the first study demonstrating that a parasitic plant can be an important force in mediating competition among resource-sharing subcortical insect herbivores.

  10. CYP345E2, an antenna-specific cytochrome P450 from the mountain pine beetle, Dendroctonus ponderosae Hopkins, catalyses the oxidation of pine host monoterpene volatiles.

    Science.gov (United States)

    Keeling, Christopher I; Henderson, Hannah; Li, Maria; Dullat, Harpreet K; Ohnishi, Toshiyuki; Bohlmann, Jörg

    2013-12-01

    The mountain pine beetle (MPB, Dendroctonus ponderosae Hopkins) is a significant pest of western North American pine forests. This beetle responds to pheromones and host volatiles in order to mass attack and thus overcome the terpenoid chemical defences of its host. The ability of MPB antennae to rapidly process odorants is necessary to avoid odorant receptor saturation and thus the enzymes responsible for odorant clearance are an important aspect of host colonization. An antenna-specific cytochrome P450, DponCYP345E2, is the most highly expressed transcript in adult MPB antenna. In in vitro assays with recombinant enzyme, DponCYP345E2 used several pine host monoterpenes as substrates, including (+)-(3)-carene, (+)-β-pinene, (-)-β-pinene, (+)-limonene, (-)-limonene, (-)-camphene, (+)-α-pinene, (-)-α-pinene, and terpinolene. The substrates were epoxidized or hydroxylated, depending upon the substrate. To complement DponCYP345E2, we also functionally characterized the NADPH-dependent cytochrome P450 reductase and the cytochrome b5 from MPB. DponCYP345E2 is the first cytochrome P450 to be functionally characterized in insect olfaction and in MPB.

  11. The legacy of attack: implications of high phloem resin monoterpene levels in lodgepole pines following mass attack by mountain pine beetle, Dendroctonus ponderosae Hopkins.

    Science.gov (United States)

    Clark, E L; Huber, D P W; Carroll, A L

    2012-04-01

    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. The sampled trees then were observed the next spring for evidence of survival, and the levels of seven resin monoterpenes were compared between July and August samples. Trees that did not survive consistently had significantly higher phloem resin monoterpene levels at the end of August compared with levels in July. Trees that did survive mainly did not exhibit a significant difference between the two sample dates. The accumulation of copious defense-related secondary metabolites in the resin of mountain pine beetle-killed lodgepole pine has important implications for describing the environmental niche that the beetle offspring survive in as well as that of parasitoids, predators, and other associates.

  12. Quantitative metabolome, proteome and transcriptome analysis of midgut and fat body tissues in the mountain pine beetle, Dendroctonus ponderosae Hopkins, and insights into pheromone biosynthesis.

    Science.gov (United States)

    Keeling, Christopher I; Li, Maria; Sandhu, Harpreet K; Henderson, Hannah; Yuen, Macaire Man Saint; Bohlmann, Jörg

    2016-03-01

    Bark beetles (Coleoptera: Scolytinae) are pests of many forests around the world. The mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, is a significant pest of western North American pine forests. The MPB is able to overcome the defences of pine trees through pheromone-assisted aggregation that results in a mass attack of host trees. These pheromones, both male and female produced, are believed to be biosynthesized in the midgut and/or fat bodies of these insects. We used metabolite analysis, quantitative proteomics (iTRAQ) and transcriptomics (RNA-seq) to identify proteins and transcripts differentially expressed between sexes and between tissues when treated with juvenile hormone III. Juvenile hormone III induced frontalin biosynthesis in males and trans-verbenol biosynthesis in females, as well as affected the expression of many proteins and transcripts in sex- and tissue-specific ways. Based on these analyses, we identified candidate genes involved in the biosynthesis of frontalin, exo-brevicomin, and trans-verbenol pheromones. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Genetic variation of lodgepole pine, Pinus contorta var. latifolia, chemical and physical defenses that affect mountain pine beetle, Dendroctonus ponderosae, attack and tree mortality.

    Science.gov (United States)

    Ott, Daniel S; Yanchuk, Alvin D; Huber, Dezene P W; Wallin, Kimberly F

    2011-09-01

    Plant secondary chemistry is determined by both genetic and environmental factors, and while large intraspecific variation in secondary chemistry has been reported frequently, the levels of genetic variation of many secondary metabolites in forest trees in the context of potential resistance against pests have been rarely investigated. We examined the effect of tree genotype and environment/site on the variation in defensive secondary chemistry of lodgepole pine, Pinus contorta var. latifolia, against the fungus, Grosmannia clavigera (formerly known as Ophiostoma clavigerum), associated with the mountain pine beetle, Dendroctonus ponderosae. Terpenoids were analyzed in phloem samples from 887, 20-yr-old trees originating from 45 half-sibling families planted at two sites. Samples were collected both pre- and post-inoculation with G. clavigera. Significant variation in constitutive and induced terpenoid compounds was attributed to differences among families. The response to the challenge inoculation with G. clavigera was strong for some individual compounds, but primarily for monoterpenoids. Environment (site) also had a significant effect on the accumulation of some compounds, whereas for others, no significant environmental effect occurred. However, for a few compounds significant family x environment interactions were found. These results suggest that P. c. latifolia secondary chemistry is under strong genetic control, but the effects depend on the individual compounds and whether or not they are expressed constitutively or following induction.

  14. Breaking out and Revelation of Dendroctonus ponderosae in Canada%加拿大高山陆均松大小蠹的爆发与启示

    Institute of Scientific and Technical Information of China (English)

    梁一萍

    2006-01-01

    高山陆均松大小蠹(Dendroctonus ponderosae)在加拿大不列颠哥伦比亚省爆发,严重地危害主要树种之一的小干松(pinus contorta).高山陆均松大小蠹的爆发过程经历了局部危害、爆发阶段、失控阶段,对环境破坏,并产生巨大经济损失,对社会的影响也极为严重.目前的防治措施主要是火烧、诱杀、卫生伐、化学防治、抢救性采伐.高山陆均松大小蠹的爆发,给人带来启示:全球气候变化对林业的影响不容忽视;树种结构单一化严重阻碍森林的可持续利用;政策的滞后同样带来危害性.

  15. Proteomics indicators of the rapidly shifting physiology from whole mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Curculionidae), adults during early host colonization.

    Science.gov (United States)

    Pitt, Caitlin; Robert, Jeanne A; Bonnett, Tiffany R; Keeling, Christopher I; Bohlmann, Jörg; Huber, Dezene P W

    2014-01-01

    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 category distributions were similar for males and females, with the majority of proteins falling under carbohydrate metabolism (glycolysis, gluconeogenesis, citric acid cycle), structure (cuticle, muscle, cytoskeleton), and protein and amino acid metabolism. Females had 23 proteins with levels that changed significantly with feeding (p<0.05, FDR<0.20), including chaperones and enzymes required for vitellogenesis. In males, levels of 29 proteins changed significantly with feeding (p<0.05, FDR<0.20), including chaperones as well as motor proteins. Only two proteins, both chaperones, exhibited a significant change in both females and males with feeding. Proteins with differential accumulation patterns in females exhibited higher fold changes with feeding than did those in males. This difference may be due to major and rapid physiological changes occurring in females upon finding a host tree during the physiological shift from dispersal to reproduction. The significant accumulation of chaperone proteins, a cytochrome P450, and a glutathione S-transferase, indicate secondary metabolite-induced stress physiology related to chemical detoxification during early host colonization. The females' activation of vitellogenin only after encountering a host indicates deliberate partitioning of resources and a balancing of the needs of dispersal and reproduction.

  16. Comparison of lodgepole and jack pine resin chemistry: implications for range expansion by the mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Curculionidae).

    Science.gov (United States)

    Clark, Erin L; Pitt, Caitlin; Carroll, Allan L; Lindgren, B Staffan; Huber, Dezene P W

    2014-01-01

    The mountain pine beetle, Dendroctonus ponderosae, is a significant pest of lodgepole pine in British Columbia (BC), where it has recently reached an unprecedented outbreak level. Although it is native to western North America, the beetle can now be viewed as a native invasive because for the first time in recorded history it has begun to reproduce in native jack pine stands within the North American boreal forest. The ability of jack pine trees to defend themselves against mass attack and their suitability for brood success will play a major role in the success of this insect in a putatively new geographic range and host. Lodgepole and jack pine were sampled along a transect extending from the beetle's historic range (central BC) to the newly invaded area east of the Rocky Mountains in north-central Alberta (AB) in Canada for constitutive phloem resin terpene levels. In addition, two populations of lodgepole pine (BC) and one population of jack pine (AB) were sampled for levels of induced phloem terpenes. Phloem resin terpenes were identified and quantified using gas chromatography. Significant differences were found in constitutive levels of terpenes between the two species of pine. Constitutive α-pinene levels - a precursor in the biosynthesis of components of the aggregation and antiaggregation pheromones of mountain pine beetle - were significantly higher in jack pine. However, lower constitutive levels of compounds known to be toxic to bark beetles, e.g., 3-carene, in jack pine suggests that this species could be poorly defended. Differences in wounding-induced responses for phloem accumulation of five major terpenes were found between the two populations of lodgepole pine and between lodgepole and jack pine. The mountain pine beetle will face a different constitutive and induced phloem resin terpene environment when locating and colonizing jack pine in its new geographic range, and this may play a significant role in the ability of the insect to persist in

  17. Change in soil fungal community structure driven by a decline in ectomycorrhizal fungi following a mountain pine beetle (Dendroctonus ponderosae) outbreak.

    Science.gov (United States)

    Pec, Gregory J; Karst, Justine; Taylor, D Lee; Cigan, Paul W; Erbilgin, Nadir; Cooke, Janice E K; Simard, Suzanne W; Cahill, James F

    2017-01-01

    Western North American landscapes are rapidly being transformed by forest die-off caused by mountain pine beetle (Dendroctonus ponderosae), with implications for plant and soil communities. The mechanisms that drive changes in soil community structure, particularly for the highly prevalent ectomycorrhizal fungi in pine forests, are complex and intertwined. Critical to enhancing understanding will be disentangling the relative importance of host tree mortality from changes in soil chemistry following tree death. Here, we used a recent bark beetle outbreak in lodgepole pine (Pinus contorta) forests of western Canada to test whether the effects of tree mortality altered the richness and composition of belowground fungal communities, including ectomycorrhizal and saprotrophic fungi. We also determined the effects of environmental factors (i.e. soil nutrients, moisture, and phenolics) and geographical distance, both of which can influence the richness and composition of soil fungi. The richness of both groups of soil fungi declined and the overall composition was altered by beetle-induced tree mortality. Soil nutrients, soil phenolics and geographical distance influenced the community structure of soil fungi; however, the relative importance of these factors differed between ectomycorrhizal and saprotrophic fungi. The independent effects of tree mortality, soil phenolics and geographical distance influenced the community composition of ectomycorrhizal fungi, while the community composition of saprotrophic fungi was weakly but significantly correlated with the geographical distance of plots. Taken together, our results indicate that both deterministic and stochastic processes structure soil fungal communities following landscape-scale insect outbreaks and reflect the independent roles tree mortality, soil chemistry and geographical distance play in regulating the community composition of soil fungi. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  18. The effect of water limitation on volatile emission, tree defense response, and brood success of Dendroctonus ponderosae in two pine hosts, lodgepole and jack pine

    Directory of Open Access Journals (Sweden)

    Inka eLusebrink

    2016-02-01

    Full Text Available The mountain pine beetle (MPB; Dendroctonus ponderosae has recently expanded its range from lodgepole pine forest into the lodgepole × jack pine hybrid zone in central Alberta, within which it has attacked pure jack pine. This study tested the effects of water limitation on tree defense response of mature lodgepole and jack pine (Pinus contorta and Pinus banksiana trees in the field. Tree defense response was initiated by inoculation of trees with the MPB-associated fungus Grosmannia clavigera and measured through monoterpene emission from tree boles and concentration of defensive compounds in phloem, needles, and necrotic tissues. Lodgepole pine generally emitted higher amounts of monoterpenes than jack pine; particularly from fungal-inoculated trees. Compared to non-inoculated trees, fungal inoculation increased monoterpene emission in both species, whereas water treatment had no effect on monoterpene emission. The phloem of both pine species contains (--α-pinene, the precursor of the beetle’s aggregation pheromone, however lodgepole pine contains two times as much as jack pine. The concentration of defensive compounds was 70-fold greater in the lesion tissue in jack pine, but only 10-fold in lodgepole pine compared to healthy phloem tissue in each species, respectively. Water-deficit treatment inhibited an increase of L-limonene as response to fungal inoculation in lodgepole pine phloem. The amount of myrcene in jack pine phloem was higher in water-deficit trees compared to ambient trees. Beetles reared in jack pine were not affected by either water or biological treatment, whereas beetles reared in lodgepole pine benefited from fungal inoculation by producing larger and heavier female offspring. Female beetles that emerged from jack pine bolts contained more fat than those that emerged from lodgepole pine, even though lodgepole pine phloem had a higher nitrogen content than jack pine phloem. These results suggest that jack pine chemistry

  19. Comparison of lodgepole and jack pine resin chemistry: implications for range expansion by the mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Curculionidae

    Directory of Open Access Journals (Sweden)

    Erin L. Clark

    2014-02-01

    Full Text Available The mountain pine beetle, Dendroctonus ponderosae, is a significant pest of lodgepole pine in British Columbia (BC, where it has recently reached an unprecedented outbreak level. Although it is native to western North America, the beetle can now be viewed as a native invasive because for the first time in recorded history it has begun to reproduce in native jack pine stands within the North American boreal forest. The ability of jack pine trees to defend themselves against mass attack and their suitability for brood success will play a major role in the success of this insect in a putatively new geographic range and host. Lodgepole and jack pine were sampled along a transect extending from the beetle’s historic range (central BC to the newly invaded area east of the Rocky Mountains in north-central Alberta (AB in Canada for constitutive phloem resin terpene levels. In addition, two populations of lodgepole pine (BC and one population of jack pine (AB were sampled for levels of induced phloem terpenes. Phloem resin terpenes were identified and quantified using gas chromatography. Significant differences were found in constitutive levels of terpenes between the two species of pine. Constitutive α-pinene levels – a precursor in the biosynthesis of components of the aggregation and antiaggregation pheromones of mountain pine beetle – were significantly higher in jack pine. However, lower constitutive levels of compounds known to be toxic to bark beetles, e.g., 3-carene, in jack pine suggests that this species could be poorly defended. Differences in wounding-induced responses for phloem accumulation of five major terpenes were found between the two populations of lodgepole pine and between lodgepole and jack pine. The mountain pine beetle will face a different constitutive and induced phloem resin terpene environment when locating and colonizing jack pine in its new geographic range, and this may play a significant role in the ability of the

  20. Proteomics indicators of the rapidly shifting physiology from whole mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Curculionidae, adults during early host colonization.

    Directory of Open Access Journals (Sweden)

    Caitlin Pitt

    Full Text Available 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 category distributions were similar for males and females, with the majority of proteins falling under carbohydrate metabolism (glycolysis, gluconeogenesis, citric acid cycle, structure (cuticle, muscle, cytoskeleton, and protein and amino acid metabolism. Females had 23 proteins with levels that changed significantly with feeding (p<0.05, FDR<0.20, including chaperones and enzymes required for vitellogenesis. In males, levels of 29 proteins changed significantly with feeding (p<0.05, FDR<0.20, including chaperones as well as motor proteins. Only two proteins, both chaperones, exhibited a significant change in both females and males with feeding. Proteins with differential accumulation patterns in females exhibited higher fold changes with feeding than did those in males. This difference may be due to major and rapid physiological changes occurring in females upon finding a host tree during the physiological shift from dispersal to reproduction. The significant accumulation of chaperone proteins, a cytochrome P450, and a glutathione S-transferase, indicate secondary metabolite-induced stress physiology related to chemical detoxification during early host colonization. The females' activation of vitellogenin only after encountering a host indicates deliberate partitioning of resources and a balancing of the needs of dispersal and reproduction.

  1. Nonhost angiosperm volatiles and verbenone protect individual ponderosa pines from attack by western pine beetle and red turpentine beetle (Coleoptera: Curculionidae, Scolytinae)

    Science.gov (United States)

    Christopher J. Fettig; Christopher P. Dabney; Stepehen R. McKelvey; Dezene P.W. Huber

    2008-01-01

    Nonhost angiosperm volatiles (NAV) and verbenone were tested for their ability to protect individual ponderosa pines, Pinus ponderosa Dougl. ex. Laws., from attack by western pine beetle (WPB), Dendroctonus brevicomis LeConte, and red turpentine beetle (RTB), Dendroctonus valens LeConte (Coleoptera: Curculionidae, Scolytinae). A combination of (

  2. Mountain Pine Beetle Dynamics and Reproductive Success in Post-Fire Lodgepole and Ponderosa Pine Forests in Northeastern Utah

    OpenAIRE

    Lerch, Andrew P.; Pfammatter, Jesse A.; Bentz, Barbara J.; Raffa, Kenneth F.

    2016-01-01

    Fire injury can increase tree susceptibility to some bark beetles (Curculionidae, Scolytinae), but whether wildfires can trigger outbreaks of species such as mountain pine beetle (Dendroctonus ponderosae Hopkins) is not well understood. We monitored 1173 lodgepole (Pinus contorta var. latifolia Doug.) and 599 ponderosa (Pinus ponderosa Doug. ex Law) pines for three years post-wildfire in the Uinta Mountains of northeastern Utah in an area with locally endemic mountain pine beetle. We examined...

  3. Host Defense Mechanisms against Bark Beetle Attack Differ between Ponderosa and Lodgepole Pines

    OpenAIRE

    West, Daniel R; Elisa J. Bernklau; Louis B. Bjostad; William R. Jacobi

    2016-01-01

    Conifer defenses against bark beetle attack include, but are not limited to, quantitative and qualitative defenses produced prior to attack. Our objective was to assess host defenses of lodgepole pine and ponderosa pine from ecotone stands. These stands provide a transition of host species for mountain pine beetle (Dendroctonus ponderosae; MPB). We asked two questions: (1) do the preformed quantitative host defenses (amount of resin) and (2) the preformed qualitative host defenses (monoterpen...

  4. Mountain pine beetle attack associated with low levels of 4-allylanisole in ponderosa pine.

    Science.gov (United States)

    Emerick, Jay J; Snyder, Aaron I; Bower, Nathan W; Snyder, Marc A

    2008-08-01

    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 found in Colorado and New Mexico using gas chromatography-mass spectroscopy (GC-MS). Although monoterpene profiles were essentially the same in attacked and nonattacked trees, significantly lower levels of 4-allylanisole were found in attacked trees compared with trees that showed no evidence of attack for both chemotypes.

  5. Efficacy of verbenone for protecting ponderosa pine stands from western pine beetle (Coleoptera: Curculionidae: Scolytinae) attack in California.

    Science.gov (United States)

    Fettig, Christopher J; McKelvey, Stephen R; Borys, Robert R; Dabney, Christopher P; Hamud, Shakeeb M; Nelson, Lori J; Seybold, Steven J

    2009-10-01

    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 pine beetle, Dendroctonus ponderosae Hopkins, and southern pine beetle, Dendroctonus frontalis Zimmermann. We evaluated the efficacy of a 5-g verbenone pouch [82%-(-); 50 mg/d] applied at 125 Ulha for protecting P. ponderosa stands (2 ha) from D. brevicomis attack over a 3-yr period. No significant differences in levels of D. brevicomis-caused tree mortality or the percentage of unsuccessfully attacked trees were found between verbenone-treated and untreated plots during each year or cumulatively over the 3-yr period. Laboratory analyses of release rates and chemical composition of volatiles emanating from verbenone pouches after field exposure found no deterioration of the active ingredient or physical malfunction of the release device. The mean release rate of pouches from all locations and exposure periods was 44.5 mg/d. In a trapping bioassay, the range of inhibition of the 5-g verbenone pouch was determined to be statistically constant 2 m from the release device. We discuss the implications of these and other results to the development of verbenone as a semiochemical-based tool for management of D. brevicomis infestations in P. ponderosa stands.

  6. Bark beetles in the genus Dendroctonus

    Science.gov (United States)

    Barbara J. Bentz

    2008-01-01

    The genus Dendroctonus (Coleoptera: Curculionidae, Scolytinae), originally described by Erichson in 1836, currently includes 19 species that are widely distributed. Seventeen species occur between Arctic North America and northwestern Nicaragua, and an additional two species are in northern Europe and Asia. Dendroctonus species attack and infest conifer hosts (Pinaceae...

  7. Host Defense Mechanisms against Bark Beetle Attack Differ between Ponderosa and Lodgepole Pines

    Directory of Open Access Journals (Sweden)

    Daniel R. West

    2016-10-01

    Full Text Available Conifer defenses against bark beetle attack include, but are not limited to, quantitative and qualitative defenses produced prior to attack. Our objective was to assess host defenses of lodgepole pine and ponderosa pine from ecotone stands. These stands provide a transition of host species for mountain pine beetle (Dendroctonus ponderosae; MPB. We asked two questions: (1 do the preformed quantitative host defenses (amount of resin and (2 the preformed qualitative host defenses (monoterpene constituents differ between lodgepole and ponderosa pines. We collected oleoresins at three locations in the Southern Rocky Mountains from 56 pairs of the pine species of similar size and growing conditions. The amount of preformed-ponderosa pine oleoresins exuded in 24 h (mg was almost four times that of lodgepole pine. Total qualitative preformed monoterpenes did not differ between the two hosts, though we found differences in all but three monoterpenes. No differences were detected in α-pinene, γ-terpinene, and bornyl acetate. We found greater concentrations of limonene, β-phellandrene, and cymene in lodgepole pines, whereas β-pinene, 3-carene, myrcene, and terpinolene were greater in ponderosa pine. Although we found differences both in quantitative and qualitative preformed oleoresin defenses, the ecological relevance of these differences to bark beetle susceptibility have not been fully tested.

  8. Antennal Transcriptome Analysis of Odorant Reception Genes in the Red Turpentine Beetle (RTB), Dendroctonus valens.

    Science.gov (United States)

    Gu, Xiao-Cui; Zhang, Ya-Nan; Kang, Ke; Dong, Shuang-Lin; Zhang, Long-Wa

    2015-01-01

    The red turpentine beetle (RTB), Dendroctonus valens LeConte (Coleoptera: Curculionidae, Scolytinae), is a destructive invasive pest of conifers which has become the second most important forest pest nationwide in China. Dendroctonus valens is known to use host odors and aggregation pheromones, as well as non-host volatiles, in host location and mass-attack modulation, and thus antennal olfaction is of the utmost importance for the beetles' survival and fitness. However, information on the genes underlying olfaction has been lacking in D. valens. Here, we report the antennal transcriptome of D. valens from next-generation sequencing, with the goal of identifying the olfaction gene repertoire that is involved in D. valens odor-processing. We obtained 51 million reads that were assembled into 61,889 genes, including 39,831 contigs and 22,058 unigenes. In total, we identified 68 novel putative odorant reception genes, including 21 transcripts encoding for putative odorant binding proteins (OBP), six chemosensory proteins (CSP), four sensory neuron membrane proteins (SNMP), 22 odorant receptors (OR), four gustatory receptors (GR), three ionotropic receptors (IR), and eight ionotropic glutamate receptors. We also identified 155 odorant/xenobiotic degradation enzymes from the antennal transcriptome, putatively identified to be involved in olfaction processes including cytochrome P450s, glutathione-S-transferases, and aldehyde dehydrogenase. Predicted protein sequences were compared with counterparts in Tribolium castaneum, Megacyllene caryae, Ips typographus, Dendroctonus ponderosae, and Agrilus planipennis. The antennal transcriptome described here represents the first study of the repertoire of odor processing genes in D. valens. The genes reported here provide a significant addition to the pool of identified olfactory genes in Coleoptera, which might represent novel targets for insect management. The results from our study also will assist with evolutionary analyses

  9. Antennal Transcriptome Analysis of Odorant Reception Genes in the Red Turpentine Beetle (RTB, Dendroctonus valens.

    Directory of Open Access Journals (Sweden)

    Xiao-Cui Gu

    Full Text Available The red turpentine beetle (RTB, Dendroctonus valens LeConte (Coleoptera: Curculionidae, Scolytinae, is a destructive invasive pest of conifers which has become the second most important forest pest nationwide in China. Dendroctonus valens is known to use host odors and aggregation pheromones, as well as non-host volatiles, in host location and mass-attack modulation, and thus antennal olfaction is of the utmost importance for the beetles' survival and fitness. However, information on the genes underlying olfaction has been lacking in D. valens. Here, we report the antennal transcriptome of D. valens from next-generation sequencing, with the goal of identifying the olfaction gene repertoire that is involved in D. valens odor-processing.We obtained 51 million reads that were assembled into 61,889 genes, including 39,831 contigs and 22,058 unigenes. In total, we identified 68 novel putative odorant reception genes, including 21 transcripts encoding for putative odorant binding proteins (OBP, six chemosensory proteins (CSP, four sensory neuron membrane proteins (SNMP, 22 odorant receptors (OR, four gustatory receptors (GR, three ionotropic receptors (IR, and eight ionotropic glutamate receptors. We also identified 155 odorant/xenobiotic degradation enzymes from the antennal transcriptome, putatively identified to be involved in olfaction processes including cytochrome P450s, glutathione-S-transferases, and aldehyde dehydrogenase. Predicted protein sequences were compared with counterparts in Tribolium castaneum, Megacyllene caryae, Ips typographus, Dendroctonus ponderosae, and Agrilus planipennis.The antennal transcriptome described here represents the first study of the repertoire of odor processing genes in D. valens. The genes reported here provide a significant addition to the pool of identified olfactory genes in Coleoptera, which might represent novel targets for insect management. The results from our study also will assist with evolutionary

  10. Mountain Pine Beetle Dynamics and Reproductive Success in Post-Fire Lodgepole and Ponderosa Pine Forests in Northeastern Utah.

    Science.gov (United States)

    Lerch, Andrew P; Pfammatter, Jesse A; Bentz, Barbara J; Raffa, Kenneth F

    2016-01-01

    Fire injury can increase tree susceptibility to some bark beetles (Curculionidae, Scolytinae), but whether wildfires can trigger outbreaks of species such as mountain pine beetle (Dendroctonus ponderosae Hopkins) is not well understood. We monitored 1173 lodgepole (Pinus contorta var. latifolia Doug.) and 599 ponderosa (Pinus ponderosa Doug. ex Law) pines for three years post-wildfire in the Uinta Mountains of northeastern Utah in an area with locally endemic mountain pine beetle. We examined how the degree and type of fire injury influenced beetle attacks, brood production, and subsequent tree mortality, and related these to beetle population changes over time. Mountain pine beetle population levels were high the first two post-fire years in lodgepole pine, and then declined. In ponderosa pine, populations declined each year after initial post-fire sampling. Compared to trees with strip or failed attacks, mass attacks occurred on trees with greater fire injury, in both species. Overall, a higher degree of damage to crowns and boles was associated with higher attack rates in ponderosa pines, but additional injury was more likely to decrease attack rates in lodgepole pines. In lodgepole pine, attacks were initially concentrated on fire-injured trees, but during subsequent years beetles attacked substantial numbers of uninjured trees. In ponderosa pine, attacks were primarily on injured trees each year, although these stands were more heavily burned and had few uninjured trees. In total, 46% of all lodgepole and 56% of ponderosa pines underwent some degree of attack. Adult brood emergence within caged bole sections decreased with increasing bole char in lodgepole pine but increased in ponderosa pine, however these relationships did not scale to whole trees. Mountain pine beetle populations in both tree species four years post-fire were substantially lower than the year after fire, and wildfire did not result in population outbreaks.

  11. Rapid Induction of Multiple Terpenoid Groups by Ponderosa Pine in Response to Bark Beetle-Associated Fungi.

    Science.gov (United States)

    Keefover-Ring, Ken; Trowbridge, Amy; Mason, Charles J; Raffa, Kenneth F

    2016-01-01

    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 been reported in ponderosa pine. We compared concentrations of terpenes and a phenylpropanoid, two phytochemical classes with strong effects against bark beetles and their symbionts, in constitutive phloem tissue and in tissue following mechanical wounding or simulated D. ponderosae attack (mechanical wounding plus inoculation with G. clavigera). We also tested whether potential induced responses were localized or systemic. Ponderosa pines showed pronounced induced defenses to inoculation, increasing their total phloem concentrations of monoterpenes 22.3-fold, sesquiterpenes 56.7-fold, and diterpenes 34.8-fold within 17 days. In contrast, responses to mechanical wounding alone were only 5.2, 11.3, and 7.7-fold, respectively. Likewise, the phenylpropanoid estragole (4-allyanisole) rose to 19.1-fold constitutive levels after simulated attack but only 4.4-fold after mechanical wounding. Overall, we found no evidence of systemic induction after 17 days, which spans most of this herbivore's narrow peak attack period, as significant quantitative and compositional changes within and between terpenoid groups were localized to the wound site. Implications to the less frequent exploitation of ponderosa than lodgepole pine by D. ponderosae, and potential advantages of rapid localized over long-term systemic responses in this system, are discussed.

  12. Mountain Pine Beetle Host Selection Between Lodgepole and Ponderosa Pines in the Southern Rocky Mountains.

    Science.gov (United States)

    West, Daniel R; Briggs, Jennifer S; Jacobi, William R; Negrón, José F

    2016-02-01

    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 dynamics and host selection behavior in the two hosts: emergence timing, sex ratios, host choice, and reproductive success. We found that peak MPB emergence from both hosts occurred simultaneously between late July and early August, and the sex ratio of emerging beetles did not differ between hosts. In two direct tests of MPB host selection, we identified a strong preference by MPB for ponderosa versus lodgepole pine. At field sites, we captured naturally emerging beetles from both natal hosts in choice arenas containing logs of both species. In the laboratory, we offered sections of bark and phloem from both species to individual insects in bioassays. In both tests, insects infested ponderosa over lodgepole pine at a ratio of almost 2:1, regardless of natal host species. Reproductive success (offspring/female) was similar in colonized logs of both hosts. Overall, our findings suggest that MPB may exhibit equally high rates of infestation and fecundity in an alternate host under favorable conditions.

  13. Genetic architecture and phenotypic plasticity of thermally-regulated traits in an eruptive species, Dendroctonus ponderosae

    Science.gov (United States)

    Barbara J. Bentz; Ryan B. Bracewell; Karen E. Mock; Michael E. Pfrender

    2011-01-01

    Phenotypic plasticity in thermally-regulated traits enables close tracking of changing environmental conditions, and can thereby enhance the potential for rapid population increase, a hallmark of outbreak insect species. In a changing climate, exposure to conditions that exceed the capacity of existing phenotypic plasticity may occur. Combining information on genetic...

  14. Review of the Geographical Distribution of Dendroctonus vitei (Curculionidae: Scolytinae) Based on Geometric Morphometrics of the Seminal Rod

    National Research Council Canada - National Science Library

    Francisco Armendáriz-Toledano; Alicia Niño; Jorge E. Macías Sámano; Gerardo Zúñiga

    2014-01-01

    .... There are also reports of the species in Veracruz, Oaxaca, and Nuevo Leon, Mexico. This bark beetle cannot be confidently distinguished from its sibling species Dendroctonus frontalis Zimmermann, Dendroctonus mexicanus Hopkins, and Dendroctonus sp. nov...

  15. Influence of elevation on bark beetle (Coleoptera: Curculionidae, Scolytinae) community structure and flight periodicity in ponderosa pine forests of Arizona.

    Science.gov (United States)

    Williams, Kelly K; McMillin, Joel D; DeGomez, Tom E; Clancy, Karen M; Miller, Andy

    2008-02-01

    We examined abundance and flight periodicity of five Ips and six Dendroctonus species (Coleoptera: Curculionidae, Scolytinae) among three different elevation bands in ponderosa pine (Pinus ponderosa Douglas ex. Lawson) forests of northcentral Arizona. Bark beetle populations were monitored at 10 sites in each of three elevation bands (low: 1,600-1,736 m; middle: 2,058-2,230 m; high: 2,505-2,651 m) for 3 yr (2004-2006) using pheromone-baited Lindgren funnel traps. Trap contents were collected weekly from March to December. We also studied temperature differences among the elevation bands and what role this may play in beetle flight behavior. Bark beetles, regardless of species, showed no consistent elevational trend in abundance among the three bands. The higher abundances of Ips lecontei Swaine, I. calligraphus ponderosae Swaine, Dendroctonus frontalis Zimmerman, and D. brevicomis LeConte at low and middle elevations offset the greater abundance of I. knausi Swaine, D. adjunctus Blandford, D. approximatus Dietz, and D. valens LeConte at high elevations. I. pini (Say) and I. latidens LeConte were found in similar numbers across the three bands. Flight periodicity of several species varied among elevation bands. In general, the flight period shortened as elevation increased; flight initiated later and terminated earlier in the year. The timing, number, and magnitude of peaks in flight activity also varied among the elevation bands. These results suggest that abundance and flight seasonality of several bark beetles are related to elevation and the associated temperature differences. The implications of these results are discussed in relation to bark beetle management and population dynamics.

  16. Late Holocene expansion of Ponderosa pine (Pinus ponderosa) in the Central Rocky Mountains, USA

    Science.gov (United States)

    Norris, Jodi R; Betancourt, Julio L.; Jackson, Stephen T.

    2016-01-01

    "Aim: Ponderosa pine (Pinus ponderosa) experienced one of the most extensive and rapid post-glacial plant migrations in western North America. We used plant macrofossils from woodrat (Neotoma) middens to reconstruct its spread in the Central Rocky Mountains, identify other vegetation changes coinciding with P. ponderosa expansion at the same sites, and relate P. ponderosa migrational history to both its modern phylogeography and to a parallel expansion by Utah juniper (Juniperus osteosperma).

  17. Diprionidae sawflies on lodgepole and ponderosa pines

    Science.gov (United States)

    Eight species of Diprionidae feed on lodgepole pine (Pinus contorta) and ponderosa pine (P. ponderosa) in western United States: Neodiprion burkei Middleton, N. annulus contortae Ross, N. autumnalis Smith, N. fulviceps (Cresson), N. gillettei (Rohwer), N. mundus Rohwer, N. ventralis Ross, and Zadi...

  18. Impacts of silvicultural thinning treatments on beetle trap captures and tree attacks during low bark beetle populations in ponderosa pine forests of northern Arizona.

    Science.gov (United States)

    Gaylord, M L; Hofstetter, R W; Wagner, M R

    2010-10-01

    Our research used a combination of passive traps, funnel traps with lures, baited trees, and surveys of long-term thinning plots to assess the impacts of different levels of stand basal area (BA) on bark beetle tree attack and on trap captures of Ips spp., Dendroctonus spp., and their predators. The study occurred at two sites in ponderosa pine, Pinus ponderosa Dougl. ex Laws., forests, from 2004 to 2007 during low bark beetle populations. Residual stand BA ranged from 9.0 to 37.0 m2/ha. More predators and bark beetles were collected in passive traps in stands of lower BA than in stands of higher BA; however, significance varied by species and site, and total number of beetles collected was low. Height of the clear panel passive traps affected trap catches for some species at some sites and years. When pheromone lures were used with funnel traps [Ips pini (Say) lure: lanierone, +03/-97 ipsdienol], we found no significant difference in trap catches among basal area treatments for bark beetles and their predators. Similarly, when trees were baited (Dendroctonus brevicomis LeConte lure: myrcene, exo-brevicomin and frontalin), we found no significant difference for days to first bark beetle attack. Surveys of long-term thinning treatments found evidence of bark beetle attacks only in unthinned plots (approximately 37 m2/ha basal area). We discuss our results in terms of management implications for bark beetle trapping and control.

  19. Nitrogen-fixing and uricolytic bacteria associated with the gut of Dendroctonus rhizophagus and Dendroctonus valens (Curculionidae: Scolytinae).

    Science.gov (United States)

    Morales-Jiménez, Jesús; Vera-Ponce de León, Arturo; García-Domínguez, Aidé; Martínez-Romero, Esperanza; Zúñiga, Gerardo; Hernández-Rodríguez, César

    2013-07-01

    The bark beetles of the genus Dendroctonus feed on phloem that is a nitrogen-limited source. Nitrogen fixation and nitrogen recycling may compensate or alleviate such a limitation, and beetle-associated bacteria capable of such processes were identified. Raoultella terrigena, a diazotrophic bacteria present in the gut of Dendroctonus rhizophagus and D. valens, exhibited high acetylene reduction activity in vitro with different carbon sources, and its nifH and nifD genes were sequenced. Bacteria able to recycle uric acid were Pseudomonas fluorescens DVL3A that used it as carbon and nitrogen source, Serratia proteomaculans 2A CDF and Rahnella aquatilis 6-DR that used uric acid as sole nitrogen source. Also, this is the first report about the uric acid content in whole eggs, larvae, and adults (male and female) samples of the red turpentine beetle (Dendroctonus valens). Our results suggest that the gut bacteria of these bark beetles could contribute to insect N balance.

  20. Resiliency of an Interior Ponderosa Pine Forest to Bark Beetle Infestations Following Fuel-Reduction and Forest-Restoration Treatments

    Directory of Open Access Journals (Sweden)

    Christopher J. Fettig

    2014-01-01

    Full Text Available Mechanical thinning and the application of prescribed fire are commonly used to restore fire-adapted forest ecosystems in the Western United States. During a 10-year period, we monitored the effects of fuel-reduction and forest-restoration treatments on levels of tree mortality in an interior ponderosa pine, Pinus ponderosa Dougl. ex Laws., forest in California. Twelve experimental plots, ranging in size from 77–144 ha, were established to create two distinct forest structural types: mid-seral stage (low structural diversity; LoD and late-seral stage (high structural diversity; HiD. Following harvesting, half of each plot was treated with prescribed fire (B. A total of 16,473 trees (8.7% of all trees died during the 10-year period. Mortality was primarily attributed to bark beetles (Coleoptera: Curculionidae, Scolytinae (10,655 trees, specifically fir engraver, Scolytus ventralis LeConte, mountain pine beetle, Dendroctonus ponderosae Hopkins, western pine beetle, D. brevicomis LeConte, pine engraver, Ips pini (Say, and, to a much lesser extent, Jeffrey pine beetle, D. jeffreyi Hopkins. Trees of all ages and size classes were killed, but mortality was concentrated in the smaller-diameter classes (19–29.2 and 29.3–39.3 cm at 1.37 m in height. Most mortality occurred three to five years following prescribed burns. Higher levels of bark beetle-caused tree mortality were observed on LoD + B (8.7% than LoD (4.2%. The application of these and other results to the   management of interior P. ponderosa forests are discussed, with an emphasis on the maintenance of large trees.

  1. Climate-influenced ponderosa pine (Pinus ponderosa) seed masting trends in western Montana, USA

    OpenAIRE

    Christopher R. Keyes; Rubén Manso González

    2015-01-01

    Aim of study: The aim of this study was to analyze 10-year records of ponderosa pine (Pinus ponderosa) seed production, in order to confirm synchronic seed production and to evaluate cyclical masting trends, masting depletion effect, and climate-masting relationships. Area of study: The study area was located in a P. ponderosa stand in the northern Rocky Mountains (western Montana, USA). Material and methods: The study was conducted in one stand that had been subjected to a silvicul...

  2. Monoterpene emission from ponderosa pine

    Science.gov (United States)

    Lerdau, Manual; Dilts, Stephen B.; Westberg, Hal; Lamb, Brian K.; Allwine, Eugene J.

    1994-01-01

    We explore the variability in monoterpene emissions from ponderosa pine beyond that which can be explained by temperature alone. Specifically, we examine the roles that photosynthesis and needle monoterpene concentrations play in controlling emissions. We measure monoterpene concentrations and emissions, photosynthesis, temperature, and light availability in the late spring and late summer in a ponderosa pine forest in central Oregon. We use a combination of measurements from cuvettes and Teflon bag enclosures to show that photosynthesis is not correlated with emissions in the short term. We also show that needle monoterpene concentrations are highly correlated with emissions for two compounds, alpha-pinene and beta-pinene, but that Delta-carene concentrations are not correlated with emissions. We suggest that direct effects of light and photosynthesis do not need to be included in emission algorithms. Our results indicate that the role of needle concentration bears further investigation; our results for alpha-pinene and beta-pinene are explainable by a Raoult's law relationship, but we cannot yet explain the cause of our results with Delta-carene.

  3. Photochemical oxidant injury and bark beetle coleoptera scolytidae infestation of ponderosa pine. I. Incidence of bark beetle infestation in injured trees

    Energy Technology Data Exchange (ETDEWEB)

    Stark, R.W.; Miller, P.R.; Cobb, F.W. Jr.; Wood, D.L.; Parmeter, J.R. Jr.

    1968-05-01

    A total of 107 beetle-killed and 963 nearest-neighbor ponderosa pines were examined to determine the association between severity of atmospheric pollution injury and infestation by bark beetles. Trees exhibiting advanced symptoms of pollution injury were most frequently infested by the western pine beetle, Dendroctonus brevicomis, and the mountain pine beetle, D. ponderosae. The degree of injury and incidence of bark beetle infestation were not related to total height, diameter, length of live and dead crown or crown class. As severity of oxidant injury increased, live crown ratio decreased and incidence of bark beetle infestation increased. One hundred noninfested trees in each of three disease categories, advanced, intermediate, and healthy, were examined for evidence of prior beetle attacks. Thirty-six percent of the advanced-diseased trees versus only 5% of the healthy trees were attacked. Thus, the beetles may discriminate between healthy and diseased trees at a distance, upon contact with the host, or both. These studies indicate strongly that atmospheric pollution injury predisposes ponderosa pine to bark beetle infestations. 3 references, 7 tables.

  4. Fungal endophytes in woody roots of Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa)

    Science.gov (United States)

    J. A. Hoff; Ned B. Klopfenstein; Geral I. McDonald; Jonalea R. Tonn; Mee-Sook Kim; Paul J. Zambino; Paul F. Hessburg; J. D. Rodgers; T. L. Peever; L. M. Carris

    2004-01-01

    The fungal community inhabiting large woody roots of healthy conifers has not been well documented. To provide more information about such communities, a survey was conducted using increment cores from the woody roots of symptomless Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa) growing in dry forests...

  5. Perceptions of ecological risk associated with mountain pine beetle (Dendroctonus ponderosae) infestations in Banff and Kootenay National Parks of Canada.

    Science.gov (United States)

    McFarlane, Bonita L; Watson, David O T; Witson, David O T

    2008-02-01

    Western Canada is experiencing an unprecedented outbreak of the mountain pine beetle (MPB). The MPB has the potential to impact some of Canada's national parks by affecting park ecosystems and the visitor experience. Controls have been initiated in some parks to lessen the impacts and to prevent the beetle from spreading beyond park boundaries. We examine the perception of ecological risk associated with MPB in two of Canada's national parks, the factors affecting perceptions of risk, and the influence of risk judgments on support for controlling MPB outbreaks in national parks. Data were collected using two studies of park visitors: a mail survey in 2003 and an onsite survey in 2005. The MPB was rated as posing a greater risk to the health and productivity of park ecosystems than anthropogenic hazards and other natural disturbance agents. Visitors who were familiar with MPB rated the ecological and visitor experience impacts as negative, unacceptable, and eliciting negative emotion. Knowledge and residency were the most consistent predictors of risk judgments. Of knowledge, risk, and demographic variables, only sex and risk to ecosystem domains influenced support for controlling the MPB in national parks. Implications for managing MPB in national parks, visitor education, and ecological integrity are discussed.

  6. Adaptive and neutral markers both show continent-wide population structure of mountain pine beetle (Dendroctonus ponderosae).

    Science.gov (United States)

    Batista, Philip D; Janes, Jasmine K; Boone, Celia K; Murray, Brent W; Sperling, Felix A H

    2016-09-01

    Assessments of population genetic structure and demographic history have traditionally been based on neutral markers while explicitly excluding adaptive markers. In this study, we compared the utility of putatively adaptive and neutral single-nucleotide polymorphisms (SNPs) for inferring mountain pine beetle population structure across its geographic range. Both adaptive and neutral SNPs, and their combination, allowed range-wide structure to be distinguished and delimited a population that has recently undergone range expansion across northern British Columbia and Alberta. Using an equal number of both adaptive and neutral SNPs revealed that adaptive SNPs resulted in a stronger correlation between sampled populations and inferred clustering. Our results suggest that adaptive SNPs should not be excluded prior to analysis from neutral SNPs as a combination of both marker sets resulted in better resolution of genetic differentiation between populations than either marker set alone. These results demonstrate the utility of adaptive loci for resolving population genetic structure in a nonmodel organism.

  7. Spatial genetic structure of the mountain pine beetle (Dendroctonus ponderosae) outbreak in western Canada: historical patterns and contemporary dispersal.

    Science.gov (United States)

    Gayathri Samarasekera, G D N; Bartell, Nicholas V; Lindgren, B Staffan; Cooke, Janice E K; Davis, Corey S; James, Patrick M A; Coltman, David W; Mock, Karen E; Murray, Brent W

    2012-06-01

    Environmental change has a wide range of ecological consequences, including species extinction and range expansion. Many studies have shown that insect species respond rapidly to climatic change. A mountain pine beetle epidemic of record size in North America has led to unprecedented mortality of lodgepole pine, and a significant range expansion to the northeast of its historic range. Our goal was to determine the spatial genetic variation found among outbreak population from which genetic structure, and dispersal patterns may be inferred. Beetles from 49 sampling locations throughout the outbreak area in western Canada were analysed at 13 microsatellite loci. We found significant north-south population structure as evidenced by: (i) Bayesian-based analyses, (ii) north-south genetic relationships and diversity gradients; and (iii) a lack of isolation-by-distance in the northernmost cluster. The north-south structure is proposed to have arisen from the processes of postglacial colonization as well as recent climate-driven changes in population dynamics. Our data support the hypothesis of multiple sources of origin for the outbreak and point to the need for population specific information to improve our understanding and management of outbreaks. The recent range expansion across the Rocky Mountains into the jack/lodgepole hybrid and pure jack pine zones of northern Alberta is consistent with a northern British Columbia origin. We detected no loss of genetic variability in these populations, indicating that the evolutionary potential of mountain pine beetle to adapt has not been reduced by founder events. This study illustrates a rapid range-wide response to the removal of climatic constraints, and the potential for range expansion of a regional population. © 2012 Blackwell Publishing Ltd.

  8. Responses of Dendroctonus brevicomis (Coleoptera: Curculionidae) in behavioral assays: implications to development of a semiochemical-based tool for tree protection.

    Science.gov (United States)

    Fettig, Christopher J; McKelvey, Stephen R; Dabney, Christopher P; Huber, Dezene P W

    2012-02-01

    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 insecticides. The responses of D. brevicomis to tree volatiles and verbenone were documented in eight experiments (trapping assays) conducted over a 4-yr period in which 88,942 individuals were collected. Geraniol, a tree volatile unique to Pinus ponderosa that elicits female-specific antennal responses in D. brevicomis, did not affect D. brevicomis behavior. Blends of two green leaf alcohols [hexanol + (Z)-3-hexen-1-ol] tested at two release rates (5.0 and 100.0 mg/d) had no effect on the response of D. brevicomis to attractant-baited traps. A nine-component blend [benzaldehyde, benzyl alcohol, guaiacol, nonanal, salicylaldehyde, (E)-2-hexenal, (E)-2-hexen-1-ol, (Z)-2-hexen-1-ol, and (-) -verbenone; NAVV] and subsequent revisions of this blend disrupted the response of D. brevicomis to attractant-baited traps in all experiments. The inhibitory effect of a revised five-component blend [nonanal, (E)-2-hexenal, (E)-2-hexen-1-ol, (Z)-2-hexen-1-ol, and (-)-verbenone; NAVV5] on the response of mountain pine beetle, D. ponderosae Hopkins, to attractant-baited traps was also documented. Acetophenone significantly reduced D. brevicomis attraction, but was not as effective as verbenone alone. Acetophenone increased the effectiveness of NAVV5 in one of two experiments. Furthermore, by adding acetophenone to NAVV5 we were able to remove the aldehydes from NAVV5 without compromising effectiveness, resulting in a novel four-component blend [acetophenone, (E)-2-hexen-1-ol + (Z)-2-hexen-1-ol, and

  9. Douglas-Fir Tussock Moth- and Douglas-Fir Beetle-Caused Mortality in a Ponderosa Pine/Douglas-Fir Forest in the Colorado Front Range, USA

    Directory of Open Access Journals (Sweden)

    José F. Negrón

    2014-12-01

    Full Text Available An outbreak of the Douglas-fir tussock moth, Orgyia pseudotsugata McDunnough, occurred in the South Platte River drainage on the Pike-San Isabel National Forest in the Colorado Front Range attacking Douglas-fir, Pseudotsuga menziesii (Mirb. Franco. Stocking levels, species composition, and tree size in heavily and lightly defoliated stands were similar. Douglas-fir tussock moth defoliation resulted in significant Douglas-fir mortality in the heavily defoliated stands, leading to a change in dominance to ponderosa pine, Pinus ponderosa Lawson. Douglas-fir beetle, Dendroctonus pseudotsuqae Hopkins, populations increased following the defoliation event but caused less mortality, and did not differ between heavily and lightly defoliated stands. Douglas-fir tussock moth-related mortality was greatest in trees less than 15 cm dbh (diameter at 1.4 m above the ground that grew in suppressed and intermediate canopy positions. Douglas-fir beetle-related mortality was greatest in trees larger than 15 cm dbh that grew in the dominant and co-dominant crown positions. Although both insects utilize Douglas-fir as its primary host, stand response to infestation is different. The extensive outbreak of the Douglas-fir tussock moth followed by Douglas-fir beetle activity may be associated with a legacy of increased host type growing in overstocked conditions as a result of fire exclusion.

  10. Antimicrobial terpenes from oleoresin of ponderosa pine tree Pinus ponderosa: A defense mechanism against microbial invasion

    Energy Technology Data Exchange (ETDEWEB)

    Himejima, Masaki; Hobson, K.R.; Otsuka, Toshikazu; Wood, D.L.; Kubo, Isao (Univ. of California, Berkeley (United States))

    1992-10-01

    The oleoresin of the ponderosa pine, Pinus ponderosa (Pinaceae) exhibited broad antimicrobial activity. In order to identify the active compounds, the oleoresin was steam distilled to give a distillate and residue. The distillate contained mainly monoterpenes and some sesquiterpenes, while the residue consisted chiefly of four structurally related diterpene acids. An antimicrobial assay with the pure compounds indicated that the monoterpenes were active primarily against fungi, but there was also some activity against gram-positive bacteria. The diterpene acids, in contrast, only exhibited activity against gram-positive bacteria. Although not all of the identified sesquiterpenes could be tested, longifolene showed activity only against gram-positive bacteria. Therefore, it appears that the oleoresin of P. ponderosa functions as a biochemical defense against microbial invasion.

  11. Evaluation of funnel traps for characterizing the bark beetle (Coleoptera: Scolytidae) communities in ponderosa pine forests of north-central Arizona.

    Science.gov (United States)

    Hayes, Christopher J; DeGomez, Tom E; Clancy, Karen M; Williams, Kelly K; McMillin, Joel D; Anhold, John A

    2008-08-01

    Lindgren funnel traps baited with aggregation pheromones are widely used to monitor and manage populations of economically important bark beetles (Coleoptera: Scolytidae). This study was designed to advance our understanding of how funnel trap catches assess bark beetle communities and relative abundance of individual species. In the second year (2005) of a 3-yr study of the bark beetle community structure in north-central Arizona pine (Pinus spp.) forests, we collected data on stand structure, site conditions, and local bark beetle-induced tree mortality at each trap site. We also collected samples of bark from infested (brood) trees near trap sites to identify and determine the population density of bark beetles that were attacking ponderosa pine, Pinus ponderosa Douglas ex Lawson, in the area surrounding the traps. Multiple regression models indicated that the number of Dendroctonus and Ips beetles captured in 2005 was inversely related to elevation of the trap site, and positively associated with the amount of ponderosa pine in the stand surrounding the site. Traps located closer to brood trees also captured more beetles. The relationship between trap catches and host tree mortality was weak and inconsistent in forest stands surrounding the funnel traps, suggesting that trap catches do not provide a good estimate of local beetle-induced tree mortality. However, pheromone-baited funnel trap data and data from gallery identification in bark samples produced statistically similar relative abundance profiles for the five species of bark beetles that we examined, indicating that funnel trap data provided a good assessment of species presence and relative abundance.

  12. Menzbieria chalcographi, a new neogregarine pathogen of the great spruce bark beetle, Dendroctonus micans (Kugelann) (Curculionidae, Scolytinae).

    Science.gov (United States)

    Yaman, Mustafa; Radek, Renate

    2012-09-01

    This study concerns a new neogregarine parasitic in the great spruce bark beetle Dendroctonus micans (Kugelann) (Curculionidae, Scolytinae). The rate of infection was high, reaching 27.3%. There was no difference in the rate of infection of male and female beetles. The life-cycle stages of the pathogen were described by light and electron microscopy. Each gametocyst of the neogregarine included 8-16 actinocephalid oocysts measuring 11.19 ± 0.42 × 4.99 ± 0.25 μm. The described pathogen has the typical characteristics of members of the genus Menzbieria within the order Neogregarinida and it was identified as Menzbieria chalcographi. This is the first record of an infection of D. micans by M. chalcographi. Possibly, this pathogen could be useful for the biological control of this destructive bark beetle.

  13. Determining the vulnerability of Mexican pine forests to bark beetles of the genus Dendroctonus Erichson (Coleoptera: Curculionidae: Scolytinae)

    Science.gov (United States)

    Y. Salinas-Moreno; A. Ager; C.F. Vargas; J.L. Hayes; G. Zuniga

    2010-01-01

    Bark beetles of the genus Dendroctonus are natural inhabitants of forests; under particular conditions some species of this genus can cause large-scale tree mortality. However, only in recent decades has priority been given to the comprehensive study of these insects in Mexico. Mexico possesses high ecological diversity in Dendroctonus-...

  14. Ancestral state reconstruction for Dendroctonus bark beetles: evolution of a tree killer.

    Science.gov (United States)

    Reeve, John D; Anderson, Frank E; Kelley, Scott T

    2012-06-01

    While most bark beetles attack only dead or weakened trees, many species in the genus Dendroctonus have the ability to kill healthy conifers through mass attack of the host tree, and can exhibit devastating outbreaks. Other species in this group are able to successfully colonize trees in small numbers without killing the host. We reconstruct the evolution of these ecological and life history traits, first classifying the extant Dendroctonus species by attack type (mass or few), outbreaks (yes or no), host genus (Pinus and others), location of attacks on the tree (bole, base, etc.), whether the host is killed (yes or no), and if the larvae are gregarious or have individual galleries (yes or no). We then estimated a molecular phylogeny for a data set of cytochrome oxidase I sequences sampled from nearly all Dendroctonus species, and used this phylogeny to reconstruct the ancestral state at various nodes on the tree, employing maximum parsimony, maximum likelihood, and Bayesian methods. Our reconstructions suggest that extant Dendroctonus species likely evolved from an ancestor that killed host pines through mass attack of the bole, had individual larvae, and exhibited outbreaks. The ability to colonize a host tree in small numbers (as well as gregarious larvae and attacks at the tree base) apparently evolved later, possibly as two separate events in different clades. It is likely that tree mortality and outbreaks have been continuing features of the interaction between conifers and Dendroctonus bark beetles.

  15. Exploring Climate Niches of Ponderosa Pine (Pinus ponderosa Douglas ex Lawson) Haplotypes in the Western United States: Implications for Evolutionary History and Conservation

    OpenAIRE

    Douglas J. Shinneman; Means, Robert E.; Potter, Kevin M.; Valerie D Hipkins

    2016-01-01

    Ponderosa pine (Pinus ponderosa Douglas ex Lawson) occupies montane environments throughout western North America, where it is both an ecologically and economically important tree species. A recent study using mitochondrial DNA analysis demonstrated substantial genetic variation among ponderosa pine populations in the western U.S., identifying 10 haplotypes with unique evolutionary lineages that generally correspond spatially with distributions of the Pacific (P. p. var. ponderosa) and Rocky ...

  16. Bacterial and fungal symbionts of parasitic Dendroctonus bark beetles.

    Science.gov (United States)

    Dohet, Loïc; Grégoire, Jean-Claude; Berasategui, Aileen; Kaltenpoth, Martin; Biedermann, Peter H W

    2016-09-01

    Bark beetles (Curculionidae: Scolytinae) are one of the most species-rich herbivorous insect groups with many shifts in ecology and host-plant use, which may be mediated by their bacterial and fungal symbionts. While symbionts are well studied in economically important, tree-killing species, little is known about parasitic species whose broods develop in living trees. Here, using culture-dependent and independent methods, we provide a comprehensive overview of the associated bacteria, yeasts and filamentous fungi of the parasitic Dendroctonus micans, D. punctatus and D. valens, and compare them to those of other tree-inhabiting insects. Despite inhabiting different geographical regions and/or host trees, the three species showed similar microbial communities. Enterobacteria were the most prevalent bacteria, in particular Rahnella, Pantoea and Ewingella, in addition to Streptomyces Likewise, the yeasts Candida/Cyberlindnera were the most prominent fungi. All these microorganisms are widespread among tree-inhabiting insects with various ecologies, but their high prevalence overall might indicate a beneficial role such as detoxification of tree defenses, diet supplementation or protection against pathogens. As such, our results enable comparisons of symbiont communities of parasitic bark beetles with those of other beetles, and will contribute to our understanding of how microbial symbioses facilitate dietary shifts in insects.

  17. Fungal associates of the lodgepole pine beetle, Dendroctonus murrayanae.

    Science.gov (United States)

    Six, Diana L; de Beer, Z Wilhelm; Duong, Tuan A; Carroll, Allan L; Wingfield, Michael J

    2011-08-01

    Bark beetles are well known vectors of ophiostomatoid fungi including species of Ophiostoma, Grosmannia and Ceratocystis. In this study, the most common ophiostomatoid fungi associated with the lodgepole pine beetle, Dendroctonus murrayanae, were characterized. Pre-emergent and post-attack adult beetles were collected from lodgepole pines at four sites in British Columbia, Canada. Fungi were isolated from these beetles and identified using a combination of morphology and DNA sequence comparisons of five gene regions. In all four populations, Grosmannia aurea was the most common associate (74-100% of all beetles) followed closely by Ophiostoma abietinum (29-75%). Other fungi isolated, in order of their relative prevalence with individual beetles were an undescribed Leptographium sp. (0-13%), Ophiostoma ips (0-15%), Ophiostoma piliferum (0-11%), a Pesotum sp. (0-11%) and Ophiostoma floccosum (0-1%). Comparisons of the DNA sequences of Leptographium strains isolated in this study, with ex-type isolates of G. aurea, Grosmannia robusta, Leptographium longiclavatum, and Leptographium terebrantis, as well as with sequences from GenBank, revealed a novel lineage within the Grosmannia clavigera complex. This lineage included some of the D. murrayane isolates as well as several isolates from previous studies referred to as L. terebrantis. However, the monophyly of this lineage is not well supported and a more comprehensive study will be needed to resolve its taxonomic status as one or more novel taxa.

  18. Drought induces spruce beetle (Dendroctonus rufipennis) outbreaks across northwestern Colorado.

    Science.gov (United States)

    Hart, Sarah J; Veblen, Thomas T; Eisenhart, Karen S; Jarvis, Daniel; Kulakowski, Dominik

    2014-04-01

    This study examines influences of climate variability on spruce beetle (Dendroctonus rufipennis) outbreak across northwestern Colorado during the period 1650 2011 CE. Periods of broad-scale outbreak reconstructed using documentary records and tree rings were dated to 1843-1860, 1882-1889, 1931-1957, and 2004-2010. Periods of outbreak were compared with seasonal temperature, precipitation, vapor pressure deficit (VPD), the Palmer Drought Severity Index (PDSI), and indices of ocean-atmosphere oscillation that include the El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO). Classification trees showed that outbreaks can be predicted most successfully from above average annual AMO values and above average summer VPD values, indicators of drought across Colorado. Notably, we find that spruce beetle outbreaks appear to be predicted best by interannual to multidecadal variability in drought, not by temperature alone. This finding may imply that spruce beetle outbreaks are triggered by decreases in host tree defenses, which are hypothesized to occur with drought stress. Given the persistence of the AMO, the shift to a positive AMO phase in the late 1990s is likely to promote continued spruce beetle disturbance.

  19. 粗点大小蠹的检疫鉴定%Quarantine ldentification of Dendroctonus punctatus

    Institute of Scientific and Technical Information of China (English)

    李健; 陆苗; 张呈伟; 李艳华; 杨光; 梁小松; 吴新华

    2014-01-01

    大小蠹属害虫是进出口木材、货物的木质包装中最易携带的害虫之一,是各国口岸检疫的重要目标。对截获的大小蠢做出快速准确的鉴定,是降低危险性大小蠢入侵我国的一个重要的方法。该文研究对象为隶属于大小蠹属中的粗点大小蠹,对其分类地位、生物学特性、鉴定特征以及传入风险等进行了详细的介绍,为粗点大小蠹的检验检疫鉴定提供参考。%Dendroctonus spp. is one of the most portable pests in imported and ex-ported timber and wooden packages, and it is an important object of the port quarantine. Making rapid and accurate identification of Dendroctonus spp. is an im-portant method to reduce the invasion risk of Dendroctonus spp. for China. ln this paper, Dendroctonus punctatus, which belongs to the Dendroctonus spp., is intro-duced in detail from the aspects of taxonomic status, biological characteristics, mor-phological characteristics and the invasion risk, providing reference for the identifica-tion of Dendroctonus punctatus in inspection and quarantine.

  20. How resilient are southwestern ponderosa pine forests after crown fires?

    OpenAIRE

    Savage, Van M.; Mast, J N

    2005-01-01

    The exclusion of low-severity surface fire from ponderosa pine (Pinus ponderosa P. & C. Lawson) forests of the Southwest has changed ecosystem structure and function such that severe crown fires are increasingly causing extensive stand mortality. This altered fire regime has resulted from the intersection of natural drought cycles with human activities that have suppressed natural fires for over a century. What is the trajectory of forest recovery after such fires? This study explores the reg...

  1. Attractant and disruptant semiochemicals for Dendroctonus jeffreyi (Coleoptera: Curculionidae: Scolytinae).

    Science.gov (United States)

    Strom, B L; Smith, S L; Brownie, C

    2013-04-01

    Jeffrey pine, Pinus jeffreyi Greville and Balfour, is a dominant yellow pine and important overstory component of forests growing on diverse sites from southwestern Oregon to Baja California to western Nevada. The Jeffrey pine beetle, Dendroctonus jeffreyi Hopkins (Coleoptera: Curculionidae: Scolytinae), is monophagous on Jeffrey pine and its primary insect pest. Despite the importance of P. jeffreyi, difficult terrain, environmental concerns, and lack of roads can constrain pest management activities. Semiochemicals are often easier to apply and more environmentally acceptable than other options, but they are lacking in this system. Attractants have been identified, but field bioassays have been limited because of infrequent or short duration outbreaks and a lack of beetles during nonoutbreak periods. Disruptant semiochemicals have not been assessed for D. jeffreyi during outbreak conditions; however, commercially available semiochemicals have been implicated as disruptants for this bark beetle. The objective of this study was to identify the most effective commercially available attractant and disruptant semiochemicals for D. jeffreyi. Our highest observed catch occurred with the blend of 5% 1-heptanol and 95% n-heptane. When this was used to challenge potential disruptant semiochemicals, the combination of S-(-)-verbenone and the green leaf volatile blend (cis-3-Hexenol and 1-Hexanol) reduced trap catch by ≍80%. However, frontalin was most effective, reducing the number of D. jeffreyi caught by >96%. Within each year of the study, the percentage female of D. jeffreyi caught with our attractant decreased from start to end of the experimental period. On average, our first collection in a year (mid-June to early July) was 59% female, whereas our last (mid-August) was 34%. Frontalin was equally or more effective against females (the pioneering sex) than males, providing optimism that semiochemical disruption may be possible for protecting Jeffrey pines from D

  2. Climate-influenced ponderosa pine (Pinus ponderosa seed masting trends in western Montana, USA

    Directory of Open Access Journals (Sweden)

    Christopher R. Keyes

    2015-04-01

    Full Text Available Aim of study: The aim of this study was to analyze 10-year records of ponderosa pine (Pinus ponderosa seed production, in order to confirm synchronic seed production and to evaluate cyclical masting trends, masting depletion effect, and climate-masting relationships. Area of study: The study area was located in a P. ponderosa stand in the northern Rocky Mountains (western Montana, USA. Material and methods: The study was conducted in one stand that had been subjected to a silvicultural study of uneven-aged management techniques that was carried out in 1984, and which resulted in three separate units consisting of one control, one cut/no-burn treatment, and one cut/burn treatment. Seeds were collected during the 10 years following treatment in 15 traps systematically deployed within each of the stand’s three units. The total numbers of seeds collected in each unit were plotted over time to analyze crop synchrony, with Spearman rank correlation coefficient used to test for masting cycles and crop depletion after a mast year. Meteorological records over the period 1983-1994 were related to the occurrence of a mast event (defined as crops exceeding 50,000 viable seeds/ha. Main results: The seed production pattern was non-cyclical, synchronous, and independent of silvicultural treatment history. A mast-depletion effect was evident but was not statistically significant. Mast events seem to be promoted by the occurrence of optimum mean temperatures at the beginning of spring during both the first (11 °C and second (9 °C years of cone maturation. The probability of a mast year was also affected by summer temperature (number of late frost days; negative effect and precipitation amount (positive effect. All these factors would seemingly explain the observed synchronous pattern in cone production. Research highlights: The non-cyclical trend of ponderosa pine seed mast years is influenced by specific climate determinants. Fluctuations in mean early

  3. Mites associated with Dendroctonus frontalis Zimmerman (Scolytidae: Coleoptera) in Central America and Mexico

    Science.gov (United States)

    John C. Moser; Robert C. Wilkinson; Edgar W. Clark

    1974-01-01

    The pine forests of central and North America continually suffer economic damage from the southern pine beetle, Dendroctonus frontalis Zimmerman 1868***, and associated bark beetles. The most severe epidemic in the history of this insect occured in Honduras from 1962 to 1965 (1, 2). Then and subsequently, studies aimed at determining the biology and...

  4. Illustrated Key to Species of Genus Dendroctonus (Coleoptera: Curculionidae) Occurring in Mexico and Central America.

    Science.gov (United States)

    Armendáriz-Toledano, Francisco; Zúñiga, Gerardo

    2017-01-01

    We provide an illustrated key of species of Dendroctonus Erichson from Mexico and Central America based on characters of the male genitalia and external morphology. The key incorporates newly identified diagnostic characters for this genus that enhance discrimination of particularly difficult sibling species. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  5. Presence and diversity of Streptomyces in Dendroctonus and sympatric bark beetle galleries across North America.

    Science.gov (United States)

    Hulcr, Jiri; Adams, Aaron S; Raffa, Kenneth; Hofstetter, Richard W; Klepzig, Kier D; Currie, Cameron R

    2011-05-01

    Recent studies have revealed several examples of intimate associations between insects and Actinobacteria, including the Southern Pine Beetle Dendroctonus frontalis and the Spruce Beetle Dendroctonus rufipennis. Here, we surveyed Streptomyces Actinobacteria co-occurring with 10 species of Dendroctonus bark beetles across the United States, using both phylogenetic and community ecology approaches. From these 10 species, and 19 other scolytine beetles that occur in the same trees, we obtained 154 Streptomyces-like isolates and generated 16S sequences from 134 of those. Confirmed 16S sequences of Streptomyces were binned into 36 distinct strains using a threshold of 0.2% sequence divergence. The 16S rDNA phylogeny of all isolates does not correlate with the distribution of strains among beetle species, localities, or parts of the beetles or their galleries. However, we identified three Streptomyces strains occurring repeatedly on Dendroctonus beetles and in their galleries. Identity of these isolates was corroborated using a house-keeping gene sequence (efTu). These strains are not confined to a certain species of beetle, locality, or part of the beetle or their galleries. However, their role as residents in the woodboring insect niche is supported by the repeated association of their 16S and efTu from across the continent, and also having been reported in studies of other subcortical insects.

  6. Differences in ponderosa pine isocupressic acid concentrations across space and time

    Science.gov (United States)

    Ponderosa Pine (Pinus ponderosa) is distributed throughout the western half of North America, where it is the most widely adapted and ubiquitous conifer. Ponderosa Pine contains isocupressic acid, a diterpene acid, which has been shown to be responsible for its abortifacient activity. The objectiv...

  7. ROLE OF CARBOHYDRATE SUPPLY IN WHITE AND BROWN ROOT RESPIRATION OF PONDEROSA PINE

    Science.gov (United States)

    Respiratory responses of fine ponderosa pine (Pinus ponderosa Laws) roots of differing morphology were measured to evaluate response to excision and to changes in the shoot light environment. Ponderosa pine seedlings were subject to either a 15:9 h light/dark environment over 24...

  8. INTERACTION OF GRASS COMPETITION AND OZONE STRESS ON C/N RATIO IN PONDEROSA PINE

    Science.gov (United States)

    Individual ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedlings were grown with three levels of blue wild-rye grass (Elymus glaucus Buckl.) (0,32, or 88 plants m-2) to determine if the presence of a natural competitor altered ponderosa pine seedling response to ozone. Gras...

  9. PONDEROSA-C/S: client–server based software package for automated protein 3D structure determination

    OpenAIRE

    Lee, Woonghee; Stark, Jaime L.; Markley, John L.

    2014-01-01

    Peak-picking Of Noe Data Enabled by Restriction Of Shift Assignments-Client Server (PONDEROSA-C/S) builds on the original PONDEROSA software (Lee et al. in Bioinformatics 27:1727–1728. doi:10.1093/bioinformatics/btr200, 2011) and includes improved features for structure calculation and refinement. PONDEROSA-C/S consists of three programs: Ponderosa Server, Ponderosa Client, and Ponderosa Analyzer. PONDEROSA-C/S takes as input the protein sequence, a list of assigned chemical shifts, and nucle...

  10. Feeding response of Ips paraconfusus to phloem and phloem metabolites of Heterobasidion annosum-inoculated ponderosa pine, Pinus ponderosa.

    Science.gov (United States)

    McNee, William R; Bonello, Pierluigi; Storer, Andrew J; Wood, David L; Gordon, Thomas R

    2003-05-01

    In studies of feeding by the bark beetle, Ips paraconfusus, two pine stilbenes (pinosylvin and pinosylvin methyl ether), ferulic acid glucoside, and enantiomers of the four most common sugars present in ponderosa pine phloem (sucrose, glucose, fructose, and raffinose) did not stimulate or reduce male feeding when assayed on wet alpha-cellulose with or without stimulatory phloem extractives present. When allowed to feed on wet alpha-cellulose containing sequential extracts (hexane, methanol, and water) of ponderosa pine phloem, methanol and water extractives stimulated feeding, but hexane extractives did not. Males confined in wet alpha-cellulose containing aqueous or organic extracts of culture broths derived from phloem tissue and containing the root pathogen. Heterobasidion annosum, ingested less substrate than beetles confined to control preparations. In an assay using logs from uninoculated ponderosa pines, the mean lengths of phloem in the digestive tracts increased as time spent feeding increased. Males confined to the phloem of basal logs cut from ponderosa pines artificially inoculated with H. annosum ingested significantly less phloem than beetles in logs cut from trees that were (combined) mock-inoculated or uninoculated and did not contain the pathogen. However, individual pathogen-containing treatments were not significantly different from uninoculated controls. It was concluded that altered feeding rates are not a major factor which may explain why diseased ponderosa pines are colonized by I. paraconfusus.

  11. Pezizalean mycorrhizas and sporocarps in ponderosa pine (Pinus ponderosa) after prescribed fires in eastern Oregon, USA.

    Science.gov (United States)

    Fujimura, K E; Smith, J E; Horton, T R; Weber, N S; Spatafora, J W

    2005-03-01

    Post-fire Pezizales fruit commonly in many forest types after fire. The objectives of this study were to determine which Pezizales appeared as sporocarps after a prescribed fire in the Blue Mountains of eastern Oregon, and whether species of Pezizales formed mycorrhizas on ponderosa pine, whether or not they were detected from sporocarps. Forty-two sporocarp collections in five genera (Anthracobia, Morchella, Peziza, Scutellinia, Tricharina) of post-fire Pezizales produced ten restriction fragment length polymorphism (RFLP) types. We found no root tips colonized by species of post-fire Pezizales fruiting at our site. However, 15% (6/39) of the RFLP types obtained from mycorrhizal roots within 32 soil cores were ascomycetes. Phylogenetic analyses of the 18S nuclear ribosomal DNA gene indicated that four of the six RFLP types clustered with two genera of the Pezizales, Wilcoxina and Geopora. Subsequent analyses indicated that two of these mycobionts were probably Wilcoxina rehmii, one Geopora cooperi, and one Geopora sp. The identities of two types were not successfully determined with PCR-based methods. Results contribute knowledge about the above- and below-ground ascomycete community in a ponderosa pine forest after a low intensity fire.

  12. Effects of ozone and climate on ponderosa pine (Pinus ponderosa) growth in the Colorado Rocky Mountains

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, D.L. (Washington Univ., Seattle, WA (United States)); Arbaugh, M.J.; Robinson, L.J. (United States Dept. of Agriculture Forest Service, Riverside, CA (United States))

    1993-01-01

    Long-term radial growth trends of ponderosa pine (Pinus ponderosa var. scopulorum) were studied in second-growth stands in the Front Range of the Colorado Rocky Mountains to determine if there has been any impact from oxidant air pollution. Although ozone concentrations are relatively high at some locations, visible pollutant injury was not found in any trees. Time series of basal area increments are generally homogeneous within stands. Concurrent periods of increasing and decreasing growth can be found in stands throughout the Front Range, which indicates that there are temporal growth trends at the regional level. Most of these trends appear to be related to the effects of stand dynamics and climate. Correlation analysis with climatic variables indicates that soil moisture supply is the dominant factor controlling interannual variation of basal area growth. Palmer hydrological drought index is highly correlated (positively) with growth during the summer months; total precipitation in spring is positively correlated with growth, and mean temperature in spring is negatively correlated with growth. There are no recent changes in growth trends that might be associated with elevated levels of ambient ozone in the Front Range. 66 refs., 5 figs., 1 tab.

  13. Responses by Dendroctonus frontalis and Dendroctonus mesoamericanus (Coleoptera: Curculionidae) to Semiochemical Lures in Chiapas, Mexico: Possible Roles of Pheromones During Joint Host Attacks.

    Science.gov (United States)

    Niño-Domínguez, Alicia; Sullivan, Brian T; López-Urbina, José H; Macías-Sámano, Jorge E

    2016-04-01

    In southern Mexico and Central America, the southern pine beetle Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae: Scolytinae) commonly colonizes host trees simultaneously with Dendroctonus mesoamericanus Armendáriz-Toledano and Sullivan, a recently described sibling species. We hypothesized that cross-species pheromone responses by host-seeking beetles might mediate joint mass attack, bole partitioning, and reproductive isolation between the species. Previous studies had indicated that D. frontalis females produce frontalin and that female D. mesoamericanus produce frontalin, endo-brevicomin, and ipsdienol (males of both species produce endo-brevicomin and possibly ipsdienol). In field trapping trials in the Mexican state of Chiapas, D. frontalis was attracted to the lure combination of turpentine and racemic frontalin; racemic endo-brevicomin enhanced this response. In a single test, D. mesoamericanus was attracted in low numbers to the combination of turpentine, racemic frontalin, and racemic endo-brevicomin after the addition of racemic ipsdienol; in contrast, racemic ipsdienol reduced responses of D. frontalis. Inhibition of D. frontalis was generated in both sexes by (+)- and racemic ipsdienol, but by (−)-ipsdienol only in females. Logs infested with D. mesoamericanus females (the pioneer sex in Dendroctonus) attracted both species in greater numbers than either D. frontalis female-infested or uninfested logs. Our data imply that D. frontalis may be more attracted to pioneer attacks of D. mesoamericanus females, and that this could be owing to the presence of endo-brevicomin in the latter. Possible intra- and inter-specific functions of semiochemicals investigated in our experiments are discussed.

  14. Comparison of orthologous cytochrome P450 genes relative expression patterns in the bark beetles Dendroctonus rhizophagus and Dendroctonus valens (Curculionidae: Scolytinae) during host colonization.

    Science.gov (United States)

    Obregón-Molina, G; Cesar-Ayala, A K; López, M F; Cano-Ramírez, C; Zúñiga, G

    2015-12-01

    Bark beetles of the genus Dendroctonus are important components of coniferous forests. During host colonization, they must overcome the chemical defences of their host trees, which are metabolized by cytochrome P450 (CYP or P450) enzymes to compounds that are readily excreted. In this study, we report the relative expression (quantitative real-time PCR) of four orthologous cytochrome P450 genes (CYP6BW5, CYP6DG1, CYP6DJ2 and CYP9Z20) in Dendroctonus rhizophagus and Dendroctonus valens forced to attack host trees at 8 and 24 h following forced attack and in four stages during natural colonization [solitary females boring the bark (T1); both male and female members of couples before oviposition (T2); both male and female members of couples during oviposition (T3), and solitary females inside the gallery containing eggs (T4)]. For both species gene expression was different compared with that observed in insects exposed to single monoterpenes in the laboratory, and the expression patterns were significantly different amongst species, sex, gut region and exposure time or natural colonization stage. The induction of genes (CYP6BW5v1, CYP6DJ2v1 and CYP9Z20v1 from D. rhizophagus, as well as CYP6DG1v3 from D. valens) correlated with colonization stage as well as with the increase in oxygenated monoterpenes in the gut of both species throughout the colonization of the host. Our results point to different functions of these orthologous genes in both species. © 2015 The Royal Entomological Society.

  15. Ophiostoma ips asociado al insecto descortezador (Dendroctonus adjunctus ) del pino de las alturas (Pinus hartwegii )

    OpenAIRE

    2009-01-01

    In the pino de las alturas (Pinus hartwegii Lindl) it has been reported the presence of the bark beetle Dendroctonus adjunctus associated with the genus Ophiostoma spp., which causes the blue-stain of the wood. The objective of this study was to identify and characterize the Ophiostoma species associated with the bark beetle D. adjunctus in P. hartwegii. Galleries and insects were collected in the Zoquiapan Experimental Forest Station (ZEFS), of the Universidad Autonoma Chapingo, in Zoquiap...

  16. Silvicultural recommendations for the management of ponderosa pine forest

    Science.gov (United States)

    Martin Alfonso Mendoza Briseno; Mary Ann Fajvan; Juan Manuel Chacon Sotelo; Alejandro Velazquez Martinez; Antonio Quinonez. Silva

    2014-01-01

    Ponderosa pines are the most important timber producing species in Mexico, and they also represent a major portion of the Usa and Canada timber production. These pines form near pure stands with simple and stable stand structure. They suffer only occasional disturbances, and they sustain a limited capacity to hold biodiversity and other senvironmental services. The...

  17. Unthinned slow-growing ponderosa pine (Pinus ponderosa) trees contain muted isotopic signals in tree rings as compared to thinned trees

    Science.gov (United States)

    We analysed the oxygen isotopic values of wood (δ18Ow) of 12 ponderosa pine (Pinus ponderosa) trees from control, moderately, and heavily thinned stands and compared them with existing wood-based estimates of carbon isotope discrimination (∆13C), basal area increment (BAI), and g...

  18. Density, heating value, and composition of pellets made from lodgepole pine (Pinus concorta Douglas) infested with mountain pine beetle (Dendroctonus ponderosae Hopkins)

    Energy Technology Data Exchange (ETDEWEB)

    Zaini, P.; Kadla, J. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Wood Science; Sokansanj, S. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Chemical and Biological Engineering; Oak Ridge National Laboratory, Oak Ridge, TN (United States). Environmental Sciences Div., Bioenergy Resource and Engineering Systems; Bi, X.; Lim, C.J. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Chemical and Biological Engineering; Mani, S. [Georgia Univ., Athens, GA (United States). Faculty of Engineering; Melin, S. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Chemical and Biological Engineering; Delta Research Corp., Delta, BC (Canada)

    2008-07-01

    BC is currently experiencing the largest recorded mountain pine beetle (MPB) infestation in North America that has killed nearly 7 million hectares of pine. The dead trees gradually lose their suitability for dimension lumber and pulp chips due to excessive cracking and spoilage. The economic losses can be partly averted by recovering the killed wood and processing it into pellets for bioenergy and other applications. Currently, Canada exports roughly 750,000 tons of wood pellets to Europe as a fuel for heat and power. The most important physical properties of wood pellets are bulk and pellet density, heating value, moisture content, and durability. In light of the chemical and structural changes reported with MPB attack, it is important to develop engineering data on properties of MPB-affected pine for wood pellets. The objective of this study was to compare chemical composition, density, and heat value of pellets made from MPB-infested wood and to compare these properties with those measured for pellets made from uninfested wood. Chemical analysis showed minor decrease in lignin and sugar contents of pellets made from MPB wood. Pellets made from MPB-infested pine had a mean value for density larger than those made from uninfested pine but the difference was not statistically significant. Heating values of the pellets from MPB-infested wood were similar to those measured for pellets from uninfested wood. A preliminary observation of mold growth did not show any further staining or other decay fungi growth for the pellets made from MPB-infested wood. The pellets made from MPB-infested wood were found to be similar to pellets made from uninfested wood in density, heating value, and most chemical constituents. The overall conclusion was that MBP infested wood can be used to produce comparable pellets to non infested wood pellets. 37 refs., 6 tabs., 2 figs.

  19. Simulation of mountain pine beetle (dendroctonus ponderosae hopkins) spread and control in British Columbia. Information report No. BC-X-329

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, A.J.

    1991-01-01

    This report describes a method of predicting the spread of the mountain pine beetle through the use of a simulation model and explains the assumptions underlying the method. Control by selective harvesting of attacked stands, use of pheromones, and various single-tree treatments are evaluated through a sensitivity analysis of the model parameters; area of attack was the indicator variable for the sensitivity analysis.

  20. Fire, fuels, and restoration of ponderosa pine-Douglas-fir forests in the Rocky Mountains

    OpenAIRE

    Baker, W. L.; T. T. Veblen; Sherriff, R. L.

    2007-01-01

    Forest restoration in ponderosa pine and mixed ponderosa pine–Douglas fir forests in the US Rocky Mountains has been highly influenced by a historical model of frequent, low-severity surface fires developed for the ponderosa pine forests of the Southwestern USA. A restoration model, based on this low-severity fire model, focuses on thinning and prescribed burning to restore historical forest structure. However, in the US Rocky Mountains, research on fire history and forest structure, and earl...

  1. Ectomycorrhizal communities of ponderosa pine and lodgepole pine in the south-central Oregon pumice zone.

    Science.gov (United States)

    Garcia, Maria O; Smith, Jane E; Luoma, Daniel L; Jones, Melanie D

    2016-05-01

    Forest ecosystems of the Pacific Northwest of the USA are changing as a result of climate change. Specifically, rise of global temperatures, decline of winter precipitation, earlier loss of snowpack, and increased summer drought are altering the range of Pinus contorta. Simultaneously, flux in environmental conditions within the historic P. contorta range may facilitate the encroachment of P. ponderosa into P. contorta territory. Furthermore, successful pine species migration may be constrained by the distribution or co-migration of ectomycorrhizal fungi (EMF). Knowledge of the linkages among soil fungal diversity, community structure, and environmental factors is critical to understanding the organization and stability of pine ecosystems. The objectives of this study were to establish a foundational knowledge of the EMF communities of P. ponderosa and P. contorta in the Deschutes National Forest, OR, USA, and to examine soil characteristics associated with community composition. We examined EMF root tips of P. ponderosa and P. contorta in soil cores and conducted soil chemistry analysis for P. ponderosa cores. Results indicate that Cenococcum geophilum, Rhizopogon salebrosus, and Inocybe flocculosa were dominant in both P. contorta and P. ponderosa soil cores. Rhizopogon spp. were ubiquitous in P. ponderosa cores. There was no significant difference in the species composition of EMF communities of P. ponderosa and P. contorta. Ordination analysis of P. ponderosa soils suggested that soil pH, plant-available phosphorus (Bray), total phosphorus (P), carbon (C), mineralizable nitrogen (N), ammonium (NH4), and nitrate (NO3) are driving EMF community composition in P. ponderosa stands. We found a significant linear relationship between EMF species richness and mineralizable N. In conclusion, P. ponderosa and P. contorta, within the Deschutes National Forest, share the same dominant EMF species, which implies that P. ponderosa may be able to successfully establish

  2. Monoterpene Variation Mediated Attack Preference Evolution of the Bark Beetle Dendroctonus valens

    OpenAIRE

    Zhudong Liu; Bo Wang; Bingbing Xu; Jianghua Sun

    2011-01-01

    Several studies suggest that some bark beetle like to attack large trees. The invasive red turpentine beetle (RTB), Dendroctonus valens LeConte, one of the most destructive forest pests in China, is known to exhibit this behavior. Our previous study demonstrated that RTBs preferred to attack large-diameter trees (diameter at breast height, DBH ≥30 cm) over small-diameter trees (DBH ≤10 cm) in the field. In the current study, we studied the attacking behavior and the underlying mechanisms in t...

  3. Estudio comparativo de Dendroctonus valens y D. rhizophagus (Curculionidae: Scolytinae) y sus hongos asociados.

    OpenAIRE

    León García, Norma

    2013-01-01

    En el presente trabajo se realizó una comparación morfológica de Dendroctonus valens y D. rhizophagus, las cuales son especies muy similares morfológicamente y esto dificulta la identificación adecuada y por lo tanto la separación de las especies. Lo anterior es importante cuando se requiere dar manejo a las plagas forestales debido a que cuando se desea aplicar algún tipo de control es importante conocer e identificar adecuadamente de qué especie se trata. El objetivo principal para este est...

  4. Mitochondrial DNA haplotype distribution patterns in Pinus ponderosa (pinaceae): range-wide evolutionary history and implications for conservation

    Science.gov (United States)

    Kevin M. Potter; Valerie D. Hipkins; Mary F. Mahalovich; Robert E. Means

    2013-01-01

    Premise of the study: Ponderosa pine ( Pinus ponderosa Douglas ex P. Lawson & C. Lawson) exhibits complicated patterns of morphological and genetic variation across its range in western North America. This study aims to clarify P. ponderosa evolutionary history and phylogeography using a highly polymorphic...

  5. Restoration of the ponderosa pine ecosystem and its understory

    Science.gov (United States)

    Lee E. Hughes

    2008-01-01

    Restoration of the Mt. Logan ponderosa pine ecosystem has been on-going since 1995. This effort included tree thinning to a density based on what the tree density was in 1870. The desired plant community objectives from the Mt. Trumbull Resource Conservation Area Plan had a forest objective as 50% trees to be in old-growth - i.e., a diameter class of 20-31.9+ inch...

  6. Uptake of trifluoroacetate by Pinus ponderosa via atmospheric pathway

    Science.gov (United States)

    Benesch, J. A.; Gustin, M. S.

    Trifluoroacetate (TFA, CF 3COO -), a break down product of hydro(chloro)-fluorocarbons (HFC/HCFCs), has been suggested to contribute to forest decline syndrome. To investigate the possible effects, Pinus ponderosa was exposed to TFA applied as mist (150 and 10,000 ng l -1) to foliar surfaces. Needles accumulated TFA as a function of concentration and time. However, no adverse physiological responses, as plant morphology, photosynthetic and conductance rates, were observed at the TFA concentrations used in this study.

  7. Cervid forage utilization in noncommercially thinned ponderosa pine forests

    Science.gov (United States)

    Gibbs, M.C.; Jenks, J.A.; Deperno, C.S.; Sowell, B.F.; Jenkins, Kurt J.

    2004-01-01

    To evaluate effects of noncommercial thinning, utilization of forages consumed by elk (Cervus elaphus L.), mule deer (Odocoileus hemionus Raf.), and white-tailed deer (Odocoileus virginianus Raf.) was measured in ponderosa pine (Pinus ponderosa P. & C. Lawson) stands in Custer State Park, S. D. Treatments consisted of unthinned (control; 22 to 32 m2/ha basal area), moderately thinned (12 to 22 m2/ha basal area), and heavily thinned (3 to 13 m2/ha basal area) stands of ponderosa pine. During June, July, and August, 1991 and 1992, about 7,000 individual plants were marked along permanent transects and percent-weight-removed by grazing was ocularly estimated. Sample plots were established along transects and plants within plots were clipped to estimate standing biomass. Pellet groups were counted throughout the study area to determine summer habitat use of elk and deer. Diet composition was evaluated using microhistological analysis of fecal samples. Average percent-weight-removed from all marked plants and percent-plants-grazed were used to evaluate forage utilization. Standing biomass of graminoids, shrubs, and forbs increased (P 0.05) across treatments. Forb use averaged less than 5% within sampling periods when measured as percent-weight-removed and percent-of-plants grazed and did not differ among treatments. Results of pellet group surveys indicated that cervids were primarily using meadow habitats. When averaged over the 2 years, forbs were the major forage class in deer diets, whereas graminoids were the major forage class in diets of elk.

  8. Gut-associated bacteria throughout the life cycle of the bark beetle Dendroctonus rhizophagus Thomas and Bright (Curculionidae: Scolytinae) and their cellulolytic activities.

    Science.gov (United States)

    Morales-Jiménez, Jesús; Zúñiga, Gerardo; Ramírez-Saad, Hugo C; Hernández-Rodríguez, César

    2012-07-01

    Dendroctonus rhizophagus Thomas and Bright (Curculionidae: Scolytinae) is an endemic economically important insect of the Sierra Madre Occidental in Mexico. This bark beetle has an atypical behavior within the genus because just one beetle couple colonizes and kills seedlings and young trees of 11 pine species. In this work, the bacteria associated with the Dendroctonus rhizophagus gut were analyzed by culture-dependent and culture-independent methods. Analysis of 16S rRNA sequences amplified directly from isolates of gut bacteria suggests that the bacterial community associated with Dendroctonus rhizophagus, like that of other Dendroctonus spp. and Ips pini, is limited in number. Nine bacterial genera of γ-Proteobacteria and Actinobacteria classes were detected in the gut of Dendroctonus rhizophagus. Stenotrophomonas and Rahnella genera were the most frequently found bacteria from Dendroctonus rhizophagus gut throughout their life cycle. Stenotrophomonas maltophilia, Ponticoccus gilvus, and Kocuria marina showed cellulolytic activity in vitro. Stenotrophomonas maltophilia, Rahnella aquatilis, Raoultella terrigena, Ponticoccus gilvus, and Kocuria marina associated with larvae or adults of Dendroctonus rhizophagus could be implicated in nitrogen fixation and cellulose breakdown, important roles associated to insect development and fitness, especially under the particularly difficult life conditions of this beetle.

  9. Site classification of ponderosa pine stands under stocking control in California

    Science.gov (United States)

    Robert F. Powers; William W. Oliver

    1978-01-01

    Existing systems for estimating site index of ponderosa pine (Pinus ponderosa Laws.) do not apply well to California stands where stocking is controlled. A more suitable system has been developed using trends in natural height growth, derived from stem analysis of dominant trees in California. This site index system produces polymorphic patterns of...

  10. EFFECTS OF ELEVATED CO2 AND N-FERTILIZATION ON SURVIVAL OF PONDEROSA PINE FINE ROOTS

    Science.gov (United States)

    We used minihizaotrons to assess the effects of elevated CO2N and season on the life-span of ponderosa pine (Pinus ponderosa Dougl. Ex Laws.) fine roots. CO2 levels were ambient air (A), ambient air + 175 ?mol mol-1 (A+175) and ambient air + 350 ?mol mol-1 (A+350). N treatments ...

  11. Snag distributions in relation to human access in ponderosa pine forests

    Science.gov (United States)

    Jeff P. Hollenbeck; Lisa J. Bate; Victoria A. Saab; John F. Lehmkuhl

    2013-01-01

    Ponderosa pine (Pinus ponderosa) forests in western North America provide habitat for numerous cavity-using wildlife species that often select large-diameter snags for nesting and roosting. Yet large snags are often removed for their commercial and firewood values. Consequently we evaluated effects of human access on snag densities and diameter-class distributions at...

  12. The 2002 Rodeo-Chediski Wildfire's impacts on southwestern ponderosa pine ecosystems, hydrology, and fuels

    Science.gov (United States)

    Peter F. Ffolliott; Cody L. Stropki; Hui Chen; Daniel G. Neary

    2011-01-01

    The Rodeo-Chediski Wildfire burned nearly 462,600 acres in north-central Arizona in the summer of 2002. The wildfire damaged or destroyed ecosystem resources and disrupted the hydrologic functioning within the impacted ponderosa pine (Pinus ponderosa) forests in a largely mosaic pattern. Impacts of the wildfire on ecosystem resources, factors important to hydrologic...

  13. The Fort Valley Experimental Forest, ponderosa pine, and wildlife habitat research

    Science.gov (United States)

    David R. Patton

    2008-01-01

    Wildlife research at the Fort Valley Experimental Forest began with studies to determine how to control damage by wildlife and livestock to ponderosa pine (Pinus ponderosa) reproduction and tree growth. Studies on birds, small mammals, and mule deer (Odocoileus hemionus) browsing were initiated in the early 1930s and 1940s but...

  14. The Fort Valley Experimental Forest, ponderosa pine, and wildlife habitat research (P-53)

    Science.gov (United States)

    David R. Patton

    2008-01-01

    Wildlife research at the Fort Valley Experimental Forest began with studies to determine how to control damage by wildlife and livestock to ponderosa pine (Pinus ponderosa) reproduction and tree growth. Studies on birds, small mammals, and mule deer (Odocoileus hemionus) browsing were initiated in the early 1930s and 1940s but these were short term efforts to develop...

  15. Modern fire regime resembles historical fire regime in a ponderosa pine forest on Native American land

    Science.gov (United States)

    Amanda B. Stan; Peter Z. Fule; Kathryn B. Ireland; Jamie S. Sanderlin

    2014-01-01

    Forests on tribal lands in the western United States have seen the return of low-intensity surface fires for several decades longer than forests on non-tribal lands. We examined the surface fire regime in a ponderosa pinedominated (Pinus ponderosa) forest on the Hualapai tribal lands in the south-western United States. Using fire-scarred trees, we inferred temporal (...

  16. Effect of geographic isolation on genetic differentiation in Dendroctonus pseudotsugae (Coleoptera: Curculionidae).

    Science.gov (United States)

    Ruiz, Enrico A; Rinehart, John E; Hayes, Jane L; Zúñiga, Gerardo

    2009-05-01

    Genetic structure of phytophagous insects has been widely studied, however, relative influence of the effect of geographic isolation, the host plant or both has been subject of considerable debate. Several studies carried out on bark beetles in the genus Dendroctonus evaluated these factors; nonetheless, recent evidence has shown that genetic structuring is a more complex process. Our goal was to examine the effect of geographic isolation on genetic structure of the Douglas-fir beetle Dendroctonus pseudotsugae. We used mtDNA cytochrome oxidase I (COI) sequences and RAPD markers. One hundred-seventy-two individuals were obtained from 17 populations, for which we analyzed 60 haplotypes (among 172 sequences of COI gene, 550 bp long) and 232 RAPD markers (7 primers). Analyses of molecular variance (AMOVA and SAMOVA), F-statistics and linear regressions suggest that the genetic structure of D. pseudotsugae is strongly influenced by geographic distance. We found that D. pseudotsugae has high intra- and inter-population genetic variation compared with several other bark beetles. Genetic differences among populations based on COI and RAPD markers were correlated with geographic distance. The observed genetic differences between northern (Canada-USA) and southern (Mexico) populations on Pseudotsuga menziesii var. glauca confirm that these two sets of populations correspond to previously assigned subspecies.

  17. Surveying the endomicrobiome and ectomicrobiome of bark beetles: The case of Dendroctonus simplex.

    Science.gov (United States)

    Durand, Audrey-Anne; Bergeron, Amélie; Constant, Philippe; Buffet, Jean-Philippe; Déziel, Eric; Guertin, Claude

    2015-11-26

    Many bark beetles belonging to the Dendroctonus genus carry bacterial and fungal microbiota, forming a symbiotic complex that helps the insect to colonize the subcortical environment of the host tree. However, the biodiversity of those bacteria at the surface of the cuticle or inside the body parts of bark beetles is not well established. The aim of this study was to characterize the bacterial microbiome associated with the eastern larch beetle, Dendroctonus simplex, using bacterial 16S rRNA gene pyrosequencing. The ecto- and endomicrobiome and the subcortical galleries were investigated. Several bacterial genera were identified, among which Pseudomonas, Serratia and Yersinia are associated with the surface of the beetle cuticle, and genera belonging to Enterobacteriaceae and Gammaproteobacteria with the interior of the insect body. The index of dissimilarity indicates that the bacterial microbiome associated with each environment constitutes exclusive groups. These results suggest the presence of distinct bacterial microbiota on the surface of the cuticle and the interior of D. simplex body. Additionally, the bacterial diversity identified in the galleries is substantially different from the ectomicrobiome, which could indicate a selection by the insect. This study reports for the first time the identification of the eastern larch beetle microbiome.

  18. The current status of the distribution range of the western pine beetle, Dendroctonus brevicomis (Curculionidae: Solytinae) in northern Mexico

    Science.gov (United States)

    O. Valerio-Mendoza; F. Armendariz-Toledano; G. Cuellar-Rodriguez; Jose F. Negron; G. Zuniga

    2017-01-01

    The distribution range of the western pine beetle Dendroctonus brevicomis LeConte (Coleoptera: Curculionidae) is supported only by scattered records in the northern parts of Mexico, suggesting that its populations may be marginal and rare in this region. In this study, we review the geographical distribution of D. brevicomis in northern Mexico and perform a geometric...

  19. Response of Lutz, Sitka, and white spruce to attack by Dendroctonus rufipennis (Coleoptera: Scolytidae) and blue stain fungi

    Science.gov (United States)

    Richard A. Werner; Barbara L. Illman

    1994-01-01

    Mechanical wounding and wounding plus inoculation with a blue-stain fungus, Leptographium abietinum (Peck), associated with the spruce beetle, Dendroctonus rufipennis (Kirby), caused an induced reaction zone or lesion around the wound sites in Lutz spruce, Picea lutzii Little, Sitka spruce, P. sitchensis (Bong.) Carr., and white spruce, P. glauca (Moench) Voss, in...

  20. Chloroplastic responses of ponderosa pine (Pinus ponderosa) seedlings to ozone exposure.

    Science.gov (United States)

    Anderson, Paul D; Palmer, Brent; Houpis, James L J; Smith, Mary K; Pushnik, James C

    2003-06-01

    Integrity of chloroplast membranes is essential to photosynthesis. Loss of thylakoid membrane integrity has been proposed as a consequence of ozone (O(3)) exposure and therefore may be a mechanistic basis for decreased photosynthetic rates commonly associated with ozone exposure. To investigate this hypothesis, Pinus ponderosa seedlings were exposed to ambient air or ozone concentrations maintained at 0.15 or 0.30 microliter l(-1) for 10 h day(-1) for 51 days during their second growing season. Over the course of the study, foliage samples were periodically collected for thylakoid membrane, chlorophyll and protein analyses. Additionally, gas-exchange measurements were made in conjunction with foliage sampling to verify that observed chloroplastic responses were associated with ozone-induced changes in photosynthesis. Needles exposed to elevated ozone exhibited decreases in chlorophyll a and b content. The decreases were dependent on the duration and intensity of ozone exposure. When based on equal amounts of chlorophyll, ozone-exposed sample tissue exhibited an increase in total protein. When based on equal amounts of protein, ozone-exposed samples exhibited an increase in 37 kDa proteins, possibly consisting of breakdown products, and a possible decrease in 68 kDa proteins, Rubisco small subunit. There was also a change in the ratio of Photosystem I protein complexes CPI and CPII that may have contributed to decreased photosynthesis. Net photosynthetic rates were decreased in the high ozone treatment suggesting that observed structural and biochemical changes in the chloroplast were associated with alterations of the photosynthetic process.

  1. Is Prey Specificity Constrained by Geography? Semiochemically Mediated Oviposition in Rhizophagus grandis (Coleoptera: Monotomidae) with Its Specific Prey, Dendroctonus micans (Coleoptera: Curculionidae: Scolytinae), and with Exotic Dendroctonus species.

    Science.gov (United States)

    Dohet, Loïc; Grégoire, Jean-Claude

    2017-08-14

    Examples of totally specific predators are rare, and the mechanisms underlying this specificity are often poorly understood. In Eurasia, the Monotomid beetle Rhizophagus grandis is found only in the galleries of its prey, the bark beetle Dendroctonus micans. The specificity of R. grandis relies on kairomones which female predators use to adjust their oviposition to the number of prey larvae available in a gallery. Yet these chemical signals are still largely unknown. The North American D. punctatus and D. valens, which are not sympatric with R. grandis but have a similar ecology as D. micans, could also elicit predator oviposition, which would suggest that specificity in this predator-prey system is constrained by geography. In order to further identify these determinants of specificity, we used artificial oviposition boxes to compare the oviposition level of R. grandis in the presence of larvae of each of the three prey species. We jointly used sequential dynamic headspace extractions and gas chromatography coupled with mass spectrometry to investigate oviposition stimuli associated with each prey species and potential oviposition inhibitors emitted by the predator. We further assessed potential stimuli with the analysis of emissions from D. micans larvae reared alone. Overall, we identified and quantified 67 compounds, mostly terpenes. Several robust candidate stimulants or inhibitors of R. grandis' oviposition were identified. The three prey species elicited similar oviposition levels in R. grandis, which suggests that this predator could form new associations outside of its native range.

  2. Ponderosa pine resin defenses and growth: metrics matter.

    Science.gov (United States)

    Hood, Sharon; Sala, Anna

    2015-11-01

    Bark beetles (Coleoptera: Curculionidae, Scolytinae) cause widespread tree mortality in coniferous forests worldwide. Constitutive and induced host defenses are important factors in an individual tree's ability to survive an attack and in bottom-up regulation of bark beetle population dynamics, yet quantifying defense levels is often difficult. For example, in Pinus spp., resin flow is important for resistance to bark beetles but is extremely variable among individuals and within a season. While resin is produced and stored in resin ducts, the specific resin duct metrics that best correlate with resin flow remain unclear. The ability and timing of some pine species to produce induced resin is also not well understood. We investigated (i) the relationships between ponderosa pine (Pinus ponderosa Lawson & C. Lawson) resin flow and axial resin duct characteristics, tree growth and physiological variables, and (ii) if mechanical wounding induces ponderosa pine resin flow and resin ducts in the absence of bark beetles. Resin flow increased later in the growing season under moderate water stress and was highest in faster growing trees. The best predictors of resin flow were nonstandardized measures of resin ducts, resin duct size and total resin duct area, both of which increased with tree growth. However, while faster growing trees tended to produce more resin, models of resin flow using only tree growth were not statistically significant. Further, the standardized measures of resin ducts, density and duct area relative to xylem area, decreased with tree growth rate, indicating that slower growing trees invested more in resin duct defenses per unit area of radial growth, despite a tendency to produce less resin overall. We also found that mechanical wounding induced ponderosa pine defenses, but this response was slow. Resin flow increased after 28 days, and resin duct production did not increase until the following year. These slow induced responses may allow

  3. A ponderosa pine natural area reveals its secrets

    Science.gov (United States)

    Allen, Craig D.

    1998-01-01

    Monument Canyon Research Natural Area preserves an unlogged 259- hectare stand of old-growth ponderosa pine in the Jemez Mountains of New Mexico. This preserve, established in 1932, is the oldest research natural area in the state. This two-tiered forest displays an old-growth density of 100 stems per hectare (Muldavin et al. 1995), with an understory thicket of stagnant saplings and poles that raises the total stand density to an average of 5,954 stems per hectare, with concentrations as high as 21,617 stems per hectare (Fig. 1).

  4. Predicting Dendroctonus pseudotsugae (Coleoptera: Curculionidae) antiaggregation pheromone concentrations using an instantaneous puff dispersion model.

    Science.gov (United States)

    Strand, Tara M; Ross, Darrell W; Thistle, Harold W; Ragenovich, Iral R; Guerra, Ivonne Matos; Lamb, Brian K

    2012-04-01

    An instantaneous puff dispersion model was used to assess concentration fields of the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, antiaggregation pheromone, 3-methylcyclohex-2-en-1-one (MCH), within a 1-ha circular plot. Several combinations of MCH release rate and releaser spacing were modeled to theoretically analyze optimal deployment strategies. The combinations of MCH release rate and releaser spacing used in the modeling exercise were based on results of previous field studies of treatment efficacy. Analyses of model results suggest that a release rate up to six times the initial standard, at a correspondingly wider spacing to keep the total amount of pheromone dispersed per unit area constant, may be effective at preventing Douglas-fir beetle infestation. The model outputs also provide a visual representation of pheromone dispersion patterns that can occur after deployment of release devices in the field. These results will help researchers and practitioners design more effective deployment strategies.

  5. Pest risk assessment of Dendroctonus valens, Hyphantria cunea and Apriona swainsoni in Beijing

    Institute of Scientific and Technical Information of China (English)

    LIU Haijun; LUO Youqing; WEN Junbao; ZHANG Zhiming; FENG Jihua; TAO Wanqiang

    2006-01-01

    According to the international methods of pest risk analysis and urban forestry characteristics in Beijing,a quantitative risk assessment system in Beijing for three primary non-indigenous pests was proposed.This system was used to analyze three major non-indigenous species,Dendroctonus valens,Hyphantria cunea,and Apriona swainsoni.The results show that the risks of these three pests in the Beijing area were 2.46,2.30,and 2.02,which were all highly risky.Based on the result and extensive risk communications,combined with the management experience of the Beijing Forest Protection Station,the authors proposed some effective control measures to prevent the invasion of the three pests into Beijing.

  6. Genetic diversity and biogeography of red turpentine beetle Dendroctonus valens in its native and invasive regions

    Institute of Scientific and Technical Information of China (English)

    Yan-Wen Cai; Xin-Yue Cheng; Ru-Mei Xu; Dong-Hong Duan; Lawrence R. Kirkendall

    2008-01-01

    Sequences of 479 bp region of the mitochondrial COI gene were applied to detect population genetic diversity and structure of Dendroctonus valens populations. By comparing the genetic diversity between native and invasive populations, it was shown that the genetic diversity of Chinese populations was obviously lower than that of native populations with both indices of haplotype diversity and Nei's genetic diversity, suggesting genetic bottleneck occurred in the invasive process of D. valens, and was then followed by a relatively quick population buildup. According to phylogenetic analyses of haplotypes, we suggested that the origin of the Chinese population was from California, USA. Phylogenetic and network analysis of native populations of D. valens revealed strong genetic structure at two distinct spatial and temporal scales in North America. The main cause resulting in current biogeographic pattern was supposedly due to recycled glacial events. Meanwhile, a cryptic species might exist in the Mexican and Guatemalan populations.

  7. Exploring Climate Niches of Ponderosa Pine (Pinus ponderosa Douglas ex Lawson Haplotypes in the Western United States: Implications for Evolutionary History and Conservation.

    Directory of Open Access Journals (Sweden)

    Douglas J Shinneman

    Full Text Available Ponderosa pine (Pinus ponderosa Douglas ex Lawson occupies montane environments throughout western North America, where it is both an ecologically and economically important tree species. A recent study using mitochondrial DNA analysis demonstrated substantial genetic variation among ponderosa pine populations in the western U.S., identifying 10 haplotypes with unique evolutionary lineages that generally correspond spatially with distributions of the Pacific (P. p. var. ponderosa and Rocky Mountain (P. p. var. scopulorum varieties. To elucidate the role of climate in shaping the phylogeographic history of ponderosa pine, we used nonparametric multiplicative regression to develop predictive climate niche models for two varieties and 10 haplotypes and to hindcast potential distribution of the varieties during the last glacial maximum (LGM, ~22,000 yr BP. Our climate niche models performed well for the varieties, but haplotype models were constrained in some cases by small datasets and unmeasured microclimate influences. The models suggest strong relationships between genetic lineages and climate. Particularly evident was the role of seasonal precipitation balance in most models, with winter- and summer-dominated precipitation regimes strongly associated with P. p. vars. ponderosa and scopulorum, respectively. Indeed, where present-day climate niches overlap between the varieties, introgression of two haplotypes also occurs along a steep clinal divide in western Montana. Reconstructed climate niches for the LGM suggest potentially suitable climate existed for the Pacific variety in the California Floristic province, the Great Basin, and Arizona highlands, while suitable climate for the Rocky Mountain variety may have existed across the southwestern interior highlands. These findings underscore potentially unique phylogeographic origins of modern ponderosa pine evolutionary lineages, including potential adaptations to Pleistocene climates associated

  8. Exploring Climate Niches of Ponderosa Pine (Pinus ponderosa Douglas ex Lawson) Haplotypes in the Western United States: Implications for Evolutionary History and Conservation.

    Science.gov (United States)

    Shinneman, Douglas J; Means, Robert E; Potter, Kevin M; Hipkins, Valerie D

    2016-01-01

    Ponderosa pine (Pinus ponderosa Douglas ex Lawson) occupies montane environments throughout western North America, where it is both an ecologically and economically important tree species. A recent study using mitochondrial DNA analysis demonstrated substantial genetic variation among ponderosa pine populations in the western U.S., identifying 10 haplotypes with unique evolutionary lineages that generally correspond spatially with distributions of the Pacific (P. p. var. ponderosa) and Rocky Mountain (P. p. var. scopulorum) varieties. To elucidate the role of climate in shaping the phylogeographic history of ponderosa pine, we used nonparametric multiplicative regression to develop predictive climate niche models for two varieties and 10 haplotypes and to hindcast potential distribution of the varieties during the last glacial maximum (LGM), ~22,000 yr BP. Our climate niche models performed well for the varieties, but haplotype models were constrained in some cases by small datasets and unmeasured microclimate influences. The models suggest strong relationships between genetic lineages and climate. Particularly evident was the role of seasonal precipitation balance in most models, with winter- and summer-dominated precipitation regimes strongly associated with P. p. vars. ponderosa and scopulorum, respectively. Indeed, where present-day climate niches overlap between the varieties, introgression of two haplotypes also occurs along a steep clinal divide in western Montana. Reconstructed climate niches for the LGM suggest potentially suitable climate existed for the Pacific variety in the California Floristic province, the Great Basin, and Arizona highlands, while suitable climate for the Rocky Mountain variety may have existed across the southwestern interior highlands. These findings underscore potentially unique phylogeographic origins of modern ponderosa pine evolutionary lineages, including potential adaptations to Pleistocene climates associated with discrete

  9. Exploring climate niches of ponderosa pine (Pinus ponderosa Douglas ex Lawson) haplotypes in the western United States: Implications for evolutionary history and conservation

    Science.gov (United States)

    Shinneman, Douglas; Means, Robert E.; Potter, Kevin M.; Hipkins, Valerie D.

    2016-01-01

    Ponderosa pine (Pinus ponderosa Douglas ex Lawson) occupies montane environments throughout western North America, where it is both an ecologically and economically important tree species. A recent study using mitochondrial DNA analysis demonstrated substantial genetic variation among ponderosa pine populations in the western U.S., identifying 10 haplotypes with unique evolutionary lineages that generally correspond spatially with distributions of the Pacific (P. p. var. ponderosa) and Rocky Mountain (P. p. var. scopulorum) varieties. To elucidate the role of climate in shaping the phylogeographic history of ponderosa pine, we used nonparametric multiplicative regression to develop predictive climate niche models for two varieties and 10 haplotypes and to hindcast potential distribution of the varieties during the last glacial maximum (LGM), ~22,000 yr BP. Our climate niche models performed well for the varieties, but haplotype models were constrained in some cases by small datasets and unmeasured microclimate influences. The models suggest strong relationships between genetic lineages and climate. Particularly evident was the role of seasonal precipitation balance in most models, with winter- and summer-dominated precipitation regimes strongly associated with P. p. vars. ponderosa and scopulorum, respectively. Indeed, where present-day climate niches overlap between the varieties, introgression of two haplotypes also occurs along a steep clinal divide in western Montana. Reconstructed climate niches for the LGM suggest potentially suitable climate existed for the Pacific variety in the California Floristic province, the Great Basin, and Arizona highlands, while suitable climate for the Rocky Mountain variety may have existed across the southwestern interior highlands. These findings underscore potentially unique phylogeographic origins of modern ponderosa pine evolutionary lineages, including potential adaptations to Pleistocene climates associated with

  10. PONDEROSA-C/S: client-server based software package for automated protein 3D structure determination.

    Science.gov (United States)

    Lee, Woonghee; Stark, Jaime L; Markley, John L

    2014-11-01

    Peak-picking Of Noe Data Enabled by Restriction Of Shift Assignments-Client Server (PONDEROSA-C/S) builds on the original PONDEROSA software (Lee et al. in Bioinformatics 27:1727-1728. doi: 10.1093/bioinformatics/btr200, 2011) and includes improved features for structure calculation and refinement. PONDEROSA-C/S consists of three programs: Ponderosa Server, Ponderosa Client, and Ponderosa Analyzer. PONDEROSA-C/S takes as input the protein sequence, a list of assigned chemical shifts, and nuclear Overhauser data sets ((13)C- and/or (15)N-NOESY). The output is a set of assigned NOEs and 3D structural models for the protein. Ponderosa Analyzer supports the visualization, validation, and refinement of the results from Ponderosa Server. These tools enable semi-automated NMR-based structure determination of proteins in a rapid and robust fashion. We present examples showing the use of PONDEROSA-C/S in solving structures of four proteins: two that enable comparison with the original PONDEROSA package, and two from the Critical Assessment of automated Structure Determination by NMR (Rosato et al. in Nat Methods 6:625-626. doi: 10.1038/nmeth0909-625 , 2009) competition. The software package can be downloaded freely in binary format from http://pine.nmrfam.wisc.edu/download_packages.html. Registered users of the National Magnetic Resonance Facility at Madison can submit jobs to the PONDEROSA-C/S server at http://ponderosa.nmrfam.wisc.edu, where instructions, tutorials, and instructions can be found. Structures are normally returned within 1-2 days.

  11. Aboveground Tree Biomass for Pinus ponderosa in Northeastern California

    Directory of Open Access Journals (Sweden)

    Todd A. Hamilton

    2013-03-01

    Full Text Available Forest managers need accurate biomass equations to plan thinning for fuel reduction or energy production. Estimates of carbon sequestration also rely upon such equations. The current allometric equations for ponderosa pine (Pinus ponderosa commonly employed for California forests were developed elsewhere, and are often applied without consideration potential for spatial or temporal variability. Individual-tree aboveground biomass allometric equations are presented from an analysis of 79 felled trees from four separate management units at Blacks Mountain Experimental Forest: one unthinned and three separate thinned units. A simultaneous set of allometric equations for foliage, branch and bole biomass were developed as well as branch-level equations for wood and foliage. Foliage biomass relationships varied substantially between units while branch and bole biomass estimates were more stable across a range of stand conditions. Trees of a given breast height diameter and crown ratio in thinned stands had more foliage biomass, but slightly less branch biomass than those in an unthinned stand. The observed variability in biomass relationships within Blacks Mountain Experimental Forest suggests that users should consider how well the data used to develop a selected model relate to the conditions in any given application.

  12. Pelletized ponderosa pine bark for adsorption of toxic heavy metals from water

    Science.gov (United States)

    Miyoung Oh; Mandla A. Tshabalala

    2007-01-01

    Bark flour from ponderosa pine (Pinus ponderosa) was consolidated into pellets using citric acid as cross-linking agent. The pellets were evaluated for removal of toxic heavy metals from synthetic aqueous solutions. When soaked in water, pellets did not leach tannins, and they showed high adsorption capacity for Cu(ll), Zn(ll), Cd(ll). and Ni(ll) under both equilibrium...

  13. Understory-overstory relationships in ponderosa pine forests, Black Hills, South Dakota

    Science.gov (United States)

    Daniel W. Uresk; Kieth E. Severson

    1989-01-01

    Under-story-overstory relationships were examined over 7 different growing stock levels(GSLs) of 2 size classes(saplings,8-10 cm d.b.h. and poles, 15-18 cm d.b.h.) of ponderosa pine (Pinus ponderosa) in the Black Hills, South Dakota. Generally, production of graminoids, forbs, and shrubs was similar between sapling and pole stands. Trends among GSLs were also similar...

  14. Peroxy Radical Chemistry and Partitioning under a Ponderosa Pine Canopy

    Science.gov (United States)

    Wolfe, G. M.; Cantrell, C. A.; Mauldin, L.; Kim, S.; Henry, S. B.; Boyle, E. S.; Karl, T.; Harley, P. C.; Turnipseed, A.; Zheng, W.; Flocke, F. M.; Apel, E. C.; Hornbrook, R. S.; Hall, S. R.; Ullmann, K.; Guenther, A. B.; DiGangi, J. P.; Kaser, L.; Schnitzhofer, R.; Hansel, A.; Graus, M.; Nakashima, Y.; Kajii, Y. J.; Keutsch, F. N.

    2012-12-01

    As the first intermediates in the OH-initiated oxidation of hydrocarbons, peroxy radicals are central to the photochemistry of the lower atmosphere. Peroxy radical abundance and partitioning controls relative rates of radical propagation and termination in low-NOx regimes, and the coupled cycling of these molecules lies at the heart of recently-highlighted deficiencies in traditional chemical mechanisms. Using observations of hydroperoxy (HO2) and total peroxy (HO2 + RO2) radicals acquired during the summer 2010 BEACHON-ROCs campaign, we explore the processes affecting radical-mediated chemistry within a rural Ponderosa pine forest in central Colorado. Steady-state and fully-coupled 0-D modeling studies are used to provide complementary perspectives on our understanding of the radical budget in this environment. Analysis will focus on the nature and impact of unidentified radical sources and sinks and on how the composition of the peroxy radical pool modulates radical regeneration.

  15. Growth of ponderosa pine seedlings as affected by air pollution

    Science.gov (United States)

    Momen, B.; Anderson, P. D.; Houpis, J. L. J.; Helms, J. A.

    The effect of air pollution on seedling survival and competitive ability is important to natural and artificial regeneration of forest trees. Although biochemical and physiological processes are sensitive indicators of pollution stress, the cumulative effects of air pollutants on seedling vigor and competitive ability may be assessed directly from whole-plant growth characteristics such as diameter, height, and photosynthetic area. A few studies that have examined intraspecific variation in seedling response to air pollution indicate that genotypic differences are important in assessing potential effects of air pollution on forest regeneration. Here, we studied the effects of acid rain (no-rain, pH 5.1 rain, pH 3.0 rain) and ozone (filtered, ambient, twice-ambient) in the field on height, diameter, volume, the height:diameter ratio, maximum needle length, and time to reach maximum needle length in seedlings of three families of ponderosa pine ( Pinus ponderosa Dougl. ex Laws). Seedling diameter, height, volume, and height:diameter ratio related significantly to their pre-treatment values. Twice-ambient ozone decreased seedling diameter compared with ozone-filtered air. A significant family-by-ozone interaction was detected for seedling height, as the height of only one of the three families was decreased by twice-ambient ozone compared with the ambient level. Seedling diameter was larger and the height:diameter ratio was smaller under pH 3.0 rain compared to either the no-rain or the pH 5.1-rain treatment. This suggests greater seedling vigor, perhaps due to a foliar fertilization effect of the pH 3.0 rain.

  16. Colonization patterns of the red turpentine beetle, Dendroctonus valens (Coleoptera: Curculionidae), in the Luliang Mountains, China

    Institute of Scientific and Technical Information of China (English)

    Zhudong Liu; Longwa Zhang; Zhanghong Shi; Bo Wang; Wan Qiang Tao; Jiang-hua Sun

    2008-01-01

    The alien red turpentine beetle (RTB), Dendroctonus valens LeConte, is one of the most economically destructive forest pests in China, having killed more than 6 million pines in recent years. There is a need to understand the basic biology and ecology of the beetle in order to develop an effective monitoring and management strategy. In this study, the effects of hillside exposure (south- and north-facing), host-tree locations according to relief (valley, mid-slope, and ridge-top) and tree diameters on RTB colonization were investigated in one valley (3 sites). The results showed that (i) RTB clearly preferred colonizing pines growing on south-facing hillsides, especially in the valley; (ii) RTB preferred to colonize the pines growing at the valley rather than pines growing at mid-slope or on ridge-top; (iii) RTB preferred to colonize trees with large diameter over small and medium-sized pines; (iv) the attack density of RTBs (measured by pitch tubes/pine) was obviously higher on larger trees standing in the valley than other trees standing at other places. We conclude from RTB colonization patterns, that RTB prefers to attack large trees in the valley, which may be useful in developing a pest-management strategy.

  17. Monoterpene variation mediated attack preference evolution of the bark beetle Dendroctonus valens.

    Science.gov (United States)

    Liu, Zhudong; Wang, Bo; Xu, Bingbing; Sun, Jianghua

    2011-01-01

    Several studies suggest that some bark beetle like to attack large trees. The invasive red turpentine beetle (RTB), Dendroctonus valens LeConte, one of the most destructive forest pests in China, is known to exhibit this behavior. Our previous study demonstrated that RTBs preferred to attack large-diameter trees (diameter at breast height, DBH ≥30 cm) over small-diameter trees (DBH ≤10 cm) in the field. In the current study, we studied the attacking behavior and the underlying mechanisms in the laboratory. Behavioral assays showed that RTBs preferred the bark of large-DBH trees and had a higher attack rate on the bolts of these trees. Y-tube assays showed that RTBs preferred the volatiles released by large-DBH trees to those released by small-DBH trees. Subsequent analysis revealed that both large- and small-DBH trees had the same composition of monoterpenes, but the concentration of each component differed; thus it appeared that the concentrations acted as cues for RTBs to locate the right-sized host which was confirmed by further behavioral assays. Moreover, large-DBH pine trees provided more spacious habitat and contained more nutrients, such as nitrogen, than did small-DBH pine trees, which benefited RTBs' fecundity and larval development. RTBs seem to have evolved mechanisms to locate those large hosts that will allow them to maximize their fitness. Monoterpene variation mediated attack preference implies the potential for the management of RTB.

  18. Sound-Triggered Production of Antiaggregation Pheromone Limits Overcrowding of Dendroctonus valens Attacking Pine Trees.

    Science.gov (United States)

    Liu, Zhudong; Xin, Yucui; Xu, Bingbing; Raffa, Kenneth F; Sun, Jianghua

    2017-01-01

    For insects that aggregate on host plants, both attraction and antiaggregation among conspecifics can be important mechanisms for overcoming host resistance and avoiding overcrowding, respectively. These mechanisms can involve multiple sensory modalities, such as sound and pheromones. We explored how acoustic and chemical signals are integrated by the bark beetle Dendroctonus valens to limit aggregation in China. In its native North American range, this insect conducts nonlethal attacks on weakened trees at very low densities, but in its introduced zone in China, it uses mixtures of host tree compounds and the pheromone component frontalin to mass attack healthy trees. We found that exo-brevicomin was produced by both female and male D. valens, and that this pheromone functioned as an antiaggregating signal. Moreover, beetles feeding in pairs or in masses were more likely than were beetles feeding alone to produce exo-brevicomin, suggesting a potential role of sound by neighboring beetles in stimulating exo-brevicomin production. Sound playback showed that an agreement sound was produced by both sexes when exposed to the aggregation pheromone frontalin and attracts males, and an aggressive sound was produced only by males behaving territorially. These signals triggered the release of exo-brevicomin by both females and males, indicating an interplay of chemical and sonic communication. This study demonstrates that the bark beetle D. valens uses sounds to regulate the production of an antiaggregation pheromone, which may provide new approaches to pest management of this invasive species.

  19. Areas of potential suitability and survival of Dendroctonus valens in China under extreme climate warming scenario.

    Science.gov (United States)

    He, S Y; Ge, X Z; Wang, T; Wen, J B; Zong, S X

    2015-08-01

    The areas in China with climates suitable for the potential distribution of the pest species red turpentine beetle (RTB) Dendroctonus valens LeConte (Coleoptera: Scolytidae) were predicted by CLIMEX based on historical climate data and future climate data with warming estimated. The model used a historical climate data set (1971-2000) and a simulated climate data set (2010-2039) provided by the Tyndall Centre for Climate Change (TYN SC 2.0). Based on the historical climate data, a wide area was available in China with a suitable climate for the beetle in which every province might contain suitable habitats for this pest, particularly all of the southern provinces. The northern limit of the distribution of the beetle was predicted to reach Yakeshi and Elunchun in Inner Mongolia, and the western boundary would reach to Keerkezi in Xinjiang Province. Based on a global-warming scenario, the area with a potential climate suited to RTB in the next 30 years (2010-2039) may extend further to the northeast. The northern limit of the distribution could reach most parts of south Heilongjiang Province, whereas the western limit would remain unchanged. Combined with the tendency for RTB to spread, the variation in suitable habitats within the scenario of extreme climate warming and the multiple geographical elements of China led us to assume that, within the next 30 years, RTB would spread towards the northeast, northwest, and central regions of China and could be a potentially serious problem for the forests of China.

  20. Sexual variation of bacterial microbiota of Dendroctonus valens guts and frass in relation to verbenone production.

    Science.gov (United States)

    Xu, Letian; Lu, Min; Xu, Dandan; Chen, Li; Sun, Jianghua

    2016-12-01

    Gut microbiota are widely involved in insect biology, and many factors can influence the microbiota in guts and frass. Dendroctonus valens is a very destructive forest pest in China, and the mass-attacking behavior is regulated by several semiochemicals, including verbenone, a multifunctional pheromone. The beetle harbors a variety of bacteria in its guts and frass and some of them are capable of verbenone production. D. valens is characterized by monogamy and female-initiated attacking behavior. Whether the bacterial communities fluctuate according to sex, and whether the variation influences the verbenone production, remains to be determined. In this study, the bacterial microbiota in D. valens guts and frass were analyzed, and verbenone production by their crude bacterial suspensions was compared in vitro. Bacterial diversity in female frass is more abundant compared to male frass, and the percentages and total amounts of main genera like Lactococcus and Pseudomonas in female frass are significantly higher than those in male frass. The verbenone produced by the female frass suspension is significantly higher than male frass. This study presents a comprehensive comparison of bacterial communities in guts and frass between both sexes of D. valens, highlighting the potential significance of female frass microbiota in verbenone production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. The pheromone frontalin and its dual function in the invasive bark beetle Dendroctonus valens.

    Science.gov (United States)

    Liu, Zhudong; Xu, Bingbing; Miao, Zhenwang; Sun, Jianghua

    2013-07-01

    The red turpentine beetle, Dendroctonus valens LeConte, is one of the most destructive invasive forest pests in China, having killed more than 6 million pines since its first outbreak in 1999. Little is known about D. valens pheromone biology and no aggregation pheromone has yet been identified. Analysis by gas chromatograph/mass spectrometer of volatiles collected from live beetles in China showed that female beetles produce frontalin and males do not. Olfactory assays in the laboratory showed that males were attracted to frontalin at a wide range of concentrations, whereas females were attracted to it at a narrow range of concentrations. In field trials, 3-carene, a monoterpene kairomone from a pine tree selected to host the beetles attracted both sexes, and when frontalin was added, the total number of beetles captured increased by almost 200%. However, increasing concentrations of frontalin significantly decreased the percentage of female beetles trapped. These results suggest a new role of frontalin as an aggregation pheromone in addition to a female-produced sex pheromone, which was previously shown in a North American population. The dual functions of the pheromone frontalin produced by D. valens females, as well as its ecological significance for overcoming host resistance, are discussed.

  2. Phylogeography reveals routes of colonization of the bark beetle Dendroctonus approximatus Dietz in Mexico.

    Science.gov (United States)

    Sánchez-Sánchez, Hermilo; López-Barrera, Gabriela; Peñaloza-Ramírez, Juan Manuel; Rocha-Ramírez, Víctor; Oyama, Ken

    2012-01-01

    We used mitochondrial DNA (mtDNA) sequence data and allele frequencies at eight microsatellite loci to examine the population genetic structure, estimate the divergence times of distinct lineages, and infer patterns associated with host colonization in populations of the bark beetle Dendroctonus approximatus in Mexico. Two haplotype groups were identified using mtDNA sequences in 71 individuals from 15 populations. The first group was distributed in the Sierra Madre Occidental (SMOc, Western Mexico), with some populations in the Faja Volcánica Transmexicana (Central Mexico), and the second was found in the Sierra Madre Oriental (SMOr, Eastern Mexico), with populations in the Sierra Madre del Sur (Southern Mexico). The estimated split between groups occurred in the late Pleistocene, around 0.195 Mya. Microsatellite allele frequencies revealed high genetic differentiation between pairwise populations, and genetic differentiation values indicated a genetic structure of isolation by distance. Both mtDNA sequence data and microsatellite allele frequencies indicated that D. approximatus had two independent colonization routes in Mexico, one through the SMOc and another along the SMOr. The widespread geographic distribution of D. approximatus in Mexico follows a model of population range expansion of two haplotype groups in which gene flow is restricted by the geographic separation between hosts imposed by physical barriers between populations.

  3. Degradation capacities of bacteria and yeasts isolated from the gut of Dendroctonus rhizophagus (Curculionidae: Scolytinae).

    Science.gov (United States)

    Briones-Roblero, Carlos I; Rodríguez-Díaz, Roberto; Santiago-Cruz, José A; Zúñiga, Gerardo; Rivera-Orduña, Flor N

    2017-01-01

    Bark beetles (Curculionidae: Scolytinae) feed on the xylem and phloem of their host, which are composed of structural carbohydrates and organic compounds that are not easily degraded by the insects. Some of these compounds might be hydrolyzed by digestive enzymes produced by microbes present in the gut of these insects. In this study, we evaluated the enzymatic capacity of bacteria (Acinetobacter lwoffii, Arthrobacter sp., Pseudomonas putida, Pseudomonas azotoformans, and Rahnella sp.) and yeasts (Candida piceae, Candida oregonensis, Cyberlindnera americana, Zygoascus sp., and Rhodotorula mucilaginosa) isolated from the Dendroctonus rhizophagus gut to hydrolyze cellulose, xylan, pectin, starch, lipids, and esters. All isolates, with the exception of C. piceae, showed lipolytic activity. Furthermore, P. putida, P. azotoformans, C. americana, C. piceae, and R. mucilaginosa presented amylolytic activity. Esterase activity was shown by A. lwoffii, P. azotoformans, and Rahnella sp. Cellulolytic and xylanolytic activities were present only in Arthrobacter sp. and P. azotoformans. The pectinolytic activity was not recorded in any isolate. This is the first study to provide evidence on the capacity of microbes associated with the D. rhizophagus gut to hydrolyze specific substrates, which might cover part of the nutritional requirements for the development, fitness, and survival of these insects.

  4. Prepupal diapause and instar IV developmental rates of the spruce beetle, Dendroctonus rufipennis (Coleoptera: Curculionidae, Scolytinae).

    Science.gov (United States)

    Hansen, E Matthew; Bentz, Barbara J; Powell, James A; Gray, David R; Vandygriff, James C

    2011-10-01

    The spruce beetle, Dendroctonus rufipennis (Kirby), is an important mortality agent of native spruces throughout North America. The life-cycle duration of this species varies from 1 to 3 years depending temperature. The univoltine cycle (one generation per year) is thought to maximize outbreak risk and accelerate host mortality in established outbreaks. Prepupal diapause is associated with the semivoltine cycle (one generation per 2 years) and we investigated thermal conditions that result in diapause induction. Preliminary experiments used respirometry in an attempt to distinguish the diapause state of experimental insects but the technique was apparently confounded by low respiration before and during pupation, regardless of diapause status. Therefore, diapause induction was deduced using developmental delays. The observed developmental response was not a "switch", with developmental delay either present or absent, but instead varied continuously. We found that temperatures 40 d cumulative exposure was associated with distinct developmental suppression. Intermediate exposure to cool temperatures resulted in minor developmental delays. We used our results to parameterize a maximum likelihood estimation model of temperature-dependent instar IV developmental rates, including the effect of diapause. This model can be included as part of a spruce beetle phenology model for predicting population dynamics. Published by Elsevier Ltd.

  5. Dendroctonus armandi (Curculionidae: Scolytinae) cytochrome P450s display tissue specificity and responses to host terpenoids.

    Science.gov (United States)

    Dai, Lulu; Ma, Mingyuan; Gao, Guanqun; Chen, Hui

    2016-11-01

    Bark beetles oxidize the defensive allelochemicals of their host trees both to detoxify them and convert them into components of their pheromone systems which were catalyzed by cytochrome P450 enzymes (CYPs) and occur in different tissues of the insect. We study P450 genes in the Chinese white pine beetle (Dendroctonus armandi), and some bio-information analysis was done for the full-length deduced amino acid sequences. The tissue specificity of these P450 genes was determined in three tissues (antenna, gut and reproductive organs). Differential expression of the P450 genes was observed between sexes, and within these significant differences exposed to stimuli (α-pinene (1:1 racemic mix), (S)-(-)-α-pinene, (S)-(-)-β-pinene, (+)-3-carene, (±)-limonene and turpentine oil) at 24h. Increased expression of P450 genes suggested that they play a role in the detoxification of monoterpenes released by the host trees. The different transcript accumulation patterns of these bark beetle P450 genes provided insight into ecological interactions of D. armandi with its host pine.

  6. Cellulolytic Bacteria Associated with the Gut of Dendroctonus armandi Larvae (Coleoptera: Curculionidae: Scolytinae

    Directory of Open Access Journals (Sweden)

    Xia Hu

    2014-03-01

    Full Text Available The object of this study was to investigate the cellulolytic bacterial community in the intestine of the Chinese white pine beetle (Dendroctonus armandi larvae. A total of 91 cellulolytic bacteria were isolated and assigned to 11 genotypes using amplified ribosomal DNA restriction analysis (ARDRA. Partial 16S rDNA sequence analysis and morphological tests were used to assign the 11 representative isolates. The results showed that the isolates belonged to α-Proteobacteria, γ-Proteobacteria and Firmicutes. Members of γ-Proteobacteria were the most frequently represented species and accounted for 73.6% of all the cellulolytic bacteria. The majority of cellulolytic bacteria in D. armandi larva gut were identified as Serratia and accounted for 49.5%, followed by Pseudomonas, which accounted for 22%. In addition, members of Bacillus, Brevundimonas, Paenibacillus, Pseudoxanthomonas, Methylobacterium and Sphingomonas were found in the D. armandi larva gut. Brevundimonas kwangchunensis, Brevundimonas vesicularis, Methylobacterium populi and Pseudoxanthomonas mexicana were reported to be cellulolytic for the first time in this study. Information generated from the present study might contribute towards understanding the relationship between bark beetle and its gut flora.

  7. Monoterpene variation mediated attack preference evolution of the bark beetle Dendroctonus valens.

    Directory of Open Access Journals (Sweden)

    Zhudong Liu

    Full Text Available Several studies suggest that some bark beetle like to attack large trees. The invasive red turpentine beetle (RTB, Dendroctonus valens LeConte, one of the most destructive forest pests in China, is known to exhibit this behavior. Our previous study demonstrated that RTBs preferred to attack large-diameter trees (diameter at breast height, DBH ≥30 cm over small-diameter trees (DBH ≤10 cm in the field. In the current study, we studied the attacking behavior and the underlying mechanisms in the laboratory. Behavioral assays showed that RTBs preferred the bark of large-DBH trees and had a higher attack rate on the bolts of these trees. Y-tube assays showed that RTBs preferred the volatiles released by large-DBH trees to those released by small-DBH trees. Subsequent analysis revealed that both large- and small-DBH trees had the same composition of monoterpenes, but the concentration of each component differed; thus it appeared that the concentrations acted as cues for RTBs to locate the right-sized host which was confirmed by further behavioral assays. Moreover, large-DBH pine trees provided more spacious habitat and contained more nutrients, such as nitrogen, than did small-DBH pine trees, which benefited RTBs' fecundity and larval development. RTBs seem to have evolved mechanisms to locate those large hosts that will allow them to maximize their fitness. Monoterpene variation mediated attack preference implies the potential for the management of RTB.

  8. INTERACTIVE EFFECTS OF CO2 AND O3 ON A PONDEROSA PINE PLANT/LITTER/SOIL MESOCOSM

    Science.gov (United States)

    To study individual and combined impacts of two important atmospheric trace gases, CO2 and O3, on C and N cycling in forest ecosystems; a four-year experiment using a small-scale ponderosa pine (Pinus ponderosa Laws.) seedling/soil/litter system was initiated in April, 1998. Th...

  9. Crossdated fire histories (1650-1900) from ponderosa pine-dominated forests of Idaho and western Montana

    Science.gov (United States)

    Emily K. Heyerdahl; Penelope Morgan; James P. Riser

    2008-01-01

    For a broader study of the climate drivers of regional-fire years in the Northern Rockies, we reconstructed a history of surface fires at 21 sites in Idaho and western Montana. We targeted sites that historically sustained frequent surface fires and were dominated or codominated by ponderosa pine (Pinus ponderosa P. & C. Lawson). Our...

  10. Dispersal of the spruce beetle, `dendroctonus rufipennis`, and the engraver beetle, `ips perturbatus`, in Alaska. Forest Service research paper

    Energy Technology Data Exchange (ETDEWEB)

    Werner, R.A.; Holsten, E.H.

    1997-09-01

    Mark-release-recapture experiments were performed with spruce beetles (Dendroctonus rufipennis (Kirby)) and Ips engraver beetles (Ips perturbatus (Eichhoff)) to determine distance and direction of dispersal. The recapture rate of beetles marked with fluorescent powder was extremely low. Most I. perturbatus beetles dispersed up to 30 m from their overwintering sites compared to most D. rufipennis, which dispersed from 90 to 300 m. Ips perturbatus beetles were caught up to 90 m and D. rufipennis up to 600 m from the point of release.

  11. Evaluation of Beauveria bassiana (Hyphomycetes) isolates as potential agents for control of Dendroctonus valens

    Institute of Scientific and Technical Information of China (English)

    Long-Wa Zhang; Yu-Jun Liu; Jian Yao; Bin Wang; Bo Huang; Zeng-Zhi Li; Mei-Zhen Fan; Jiang-Hua Sun

    2011-01-01

    The red turpentine beetle (RTB), Dendroctonus valens LeConte, as a destructive invasive pest, has become one of the most economically important forest pest in China. Effective control measures are desperately needed. Entomopathogenic fungi, such as Beauveria bassiana, have shown great potential for the management of some bark beetle species. In this study, 12 isolates of B. bassiana from bark beetle were examined for biological characteristics and virulence, to assess their potential as biocontrol agents for RTB. There were significant differences (at P = 0.05) in colony growth rate, conidial yield, conidial germination, tolerance to UV light and extracellular proteases activity among the tested B. bassiana isolates. Isolates, including Bbl801, Bbl906, Bb789 and Bb773, exhibited the best characteristics, because they have faster hyphal growth rate, higher spore production and faster spore germination, higher UV tolerance and protease (Prl) production. The results of a pathogenicity test of B. bassiana on RTB larvae showed that most isolates of B. bassiana have demonstrated high efficacy and the highest virulent isolate was Bbl801, which killed 100% of the treated insects and had a median lethal time (LT50) of 4.60 days at a concentration of 1× 107 conidia/mL. Therefore, isolate Bb 1801 has a great potential for sustainable control of RTB in the forest. The correlation between biological characteristics and virulence of the fungal isolates is discussed and the possibility of combination of entomopathogenic fungi with semiochemicals, as one of the promising strategy for RTB control, is considered.

  12. Gut-Associated Bacteria of Dendroctonus valens and their Involvement in Verbenone Production.

    Science.gov (United States)

    Xu, Letian; Lou, Qiaozhe; Cheng, Chihang; Lu, Min; Sun, Jianghua

    2015-11-01

    Bark beetles are the most important mortality agent in coniferous forests, and pheromones play important roles in their management. Dendroctonus valens LeConte was introduced from North America to China and has killed millions of healthy pines there. Trapping with semiochemicals and pheromones was deployed in D. valens management in the last decade, but little is known about the ability of gut bacteria to produce the pheromone. In this study, we analyzed the volatiles in D. valens guts and frass after antibiotic treatment versus control. Then, we isolated and identified the bacteria in D. valens guts and frass, examined verbenone (a multifunctional pheromone of D. valens) production by 16 gut bacterial isolates from the precursor cis-verbenol at three concentrations, and further compared the cytotoxicities between the cis-verbenol and verbenone to the bacterial isolates. cis-Verbenol was not detected in the frass in the control group, but it was in the antibiotic treatment. The amount of verbenone was significantly suppressed in D. valens guts after antibiotic treatment versus control. Thirteen out of 16 gut bacterial isolates were capable of cis-verbenol to verbenone conversion, and cis-verbenol had stronger cytotoxicities than verbenone to all tested gut bacterial isolates. The bacterial species capable of verbenone production largely exists in D. valens guts and frass, suggesting that gut-associated bacteria may help the bark beetle produce the pheromone verbenone in guts and frass. The bacteria may benefit from the conversion due to the reduced cytotoxicity from the precursor to the beetle pheromone.

  13. Southern pine beetle, Dendroctonus frontalis, antennal and behavioral responses to nonhost leaf and bark volatiles.

    Science.gov (United States)

    Shepherd, William P; Sullivan, Brian T

    2013-04-01

    A growing body of evidence suggests that bark beetles detect and avoid release points of volatile compounds associated with nonhost species, and thus such nonhost volatiles may have potential utility in the management of bark beetles. We used a coupled gas chromatograph-electroantennographic detector (GC-EAD) to assay the olfactory sensitivity of the southern pine beetle, Dendroctonus frontalis Zimmermann, to volatiles from leaves and bark of eight species of nonhost angiosperm trees that are common in the range of D. frontalis. Tree species sampled were red maple (Acer rubrum L.), mockernut hickory [Carya alba (L.) Nutt. ex Ell.], sweetgum (Liquidambar styraciflua L.), black tupelo (Nyssa sylvatica Marsh.), black cherry (Prunus serotina Ehrh.), southern red oak (Quercus falcata Michx.), blackjack oak [Quercus marilandica (L.) Muenchh.], and water oak (Quercus nigra L.). Beetle antennae responded to a total of 28 identifiable compounds in these samples. The relative olfactory responsiveness to 14 of these, as well as to nonanoic acid and four additional volatiles reported to be associated with nonhost angiosperms, was assessed in GC-EAD analyses of synthetic dilutions spanning six orders of magnitude. The largest response voltage amplitudes were obtained with trans-conophthorin, nonanoic acid, terpinen-4-ol, phenylethyl alcohol, and eucalyptol, whereas the lowest response thresholds were to nonanoic acid, nonanal, linalool, (E)-2-hexen-1-ol, and phenylethyl alcohol. Funnel traps baited with various combinations of eleven antennally-active angiosperm volatiles along with a standard attractant captured significantly fewer male and female D. frontalis than traps baited with the standard attractant alone. Our data suggest that a diversity of semiochemicals may be involved in host species discrimination by D. frontalis, and several may have utility in their management.

  14. Climate variability and spruce beetle (Dendroctonus rufipennis) outbreaks in south-central and southwest Alaska.

    Science.gov (United States)

    Sherriff, Rosemary L; Berg, Edward E; Miller, Amy E

    2011-07-01

    We used tree ring data (AD 1601-2007) to examine the occurrence of and climatic influences on spruce beetle (Dendroctonus rufipennis) outbreaks in south-central and southwest Alaska and found evidence of regional-scale outbreaks dating from the mid-1700s, related to climate variability at multiple temporal scales. Over interannual time scales (approximately 1-3 years), El Niño years, combined with severe late-summer drought, appeared to contribute significantly to spruce beetle outbreaks in the study area. Over multidecadal time scales (up to approximately 40 years), cool-phase Pacific Decadal Oscillation (PDO) conditions tended to precede beetle outbreaks, regardless of the phase of El Niño-Southern Oscillation (ENSO). All sites showed low-severity disturbances attributed to spruce beetle damage, most notably during the 1810s. During other major periods of disturbance (i.e., 1870s, 1910s, 1970s), the effects of spruce beetle outbreaks were of moderate or higher severity. The highly synchronized timing of spruce beetle outbreaks at interannual to multidecadal scales, and particularly the association between cool-phase PDO conditions and beetle disturbance, suggests that climate (i.e., temperature, precipitation) is a primary driver of outbreaks in the study area. Our disturbance chronologies (mid-1700s to present) suggest that recent irruptions (1990s to present) in south-central and southwest Alaska are within the historical geographic range, but that outbreaks since the 1990s show greater spatiotemporal synchrony (i.e., more sites record high-severity infestations) than at any other time in the past approximatly 250 years.

  15. New record and extension of the distribution range of the bark beetle Dendroctonus rhizophagus (Curculionidae: Scolytinae Nuevo registro y ampliación del área de distribución del descortezador Dendroctonus rhizophagus (Curculionidae: Scolytinae

    Directory of Open Access Journals (Sweden)

    Francisco Armendáriz-Toledano

    2012-09-01

    Full Text Available After several exploratory surveys to the states of Jalisco and Zacatecas in the Sierra Madre Occidental (SMOC, the bark beetle Dendroctonus rhizophagus Thomas and Bright, 1970 was recorded in 2 geographic localities of Villa Guerrero, Jalisco. These new records extend the range of distribution of this beetle a further 250 km south along the SMOC from the southernmost site recorded in the state of Durango. These records indicate that this species may be present in almost any area of the SMOC where conditions are suitable for its development.Después de varios viajes de exploración a los estados de Jalisco y Zacatecas en la sierra Madre Occidental (SMOC, se registró la presencia del descortezador Dendroctonus rhizophagus Thomas y Bright, 1970 en 2 localidades en el Municipio de Villa Guerrero, Jalisco. Estos nuevos registros amplían el área de distribución del descortezador 250 km hacia el sur de la SMOC, a partir del punto más sureño registrado en el estado de Durango. Asimismo, estos registros indican que esta especie puede estar presente en prácticamente cualquier área de la SMOC que reúna las condiciones adecuadas para su desarrollo.

  16. Pheromone-Mediated Mate Location and Discrimination by Two Syntopic Sibling Species of Dendroctonus Bark Beetles in Chiapas, Mexico.

    Science.gov (United States)

    Niño-Domínguez, Alicia; Sullivan, Brian T; López-Urbina, José H; Macías-Sámano, Jorge E

    2015-08-01

    Where their geographic and host ranges overlap, sibling species of tree-killing bark beetles may simultaneously attack and reproduce on the same hosts. However, sustainability of these potentially mutually beneficial associations demands effective prezygotic reproductive isolation mechanisms between the interacting species. The pine bark beetle, Dendroctonus frontalis Zimmermann, is syntopic in the Central American region with a recently described sibling species, Dendroctonus mesoamericanus Armendáriz-Toledano and Sullivan, but mechanisms for their reproductive isolation are uncertain. We investigated whether semiochemicals mediate species discrimination by mate-seeking males of both species. In olfactometer bioassays, walking males of both species strongly preferred odors from gallery entrances of conspecific females. Coupled gas chromatography-electroantennographic detection and gas chromatography-mass spectrometry isolated 16 olfactory stimulants for males in these odors, but only two, ipsdienol and endo-brevicomin (both from D. mesoamericanus females), differed in quantity in female-associated odors between the species. In olfactometer bioassays, with 10, 1, or 0.1 female entrance equivalents of synthetic semiochemicals, the combination of ipsdienol and endo-brevicomin inhibited responses of male D. frontalis and enhanced responses of male D. mesoamericanus to two compounds associated with female entrances of both species (the pheromone component frontalin and host odor α-pinene). We conclude that ipsdienol and endo-brevicomin, pheromone components produced by females of just one of the two species (D. mesoamericanus), mediate interspecific mate discrimination by males of both species and provide an apparently symmetrical reproductive isolation mechanism.

  17. Effect of associated fungi on the immunocompetence of red turpentine beetle larvae, Dendroctonus valens (Coleoptera: Curculionidae: Scolytinae)

    Institute of Scientific and Technical Information of China (English)

    Zhang-Hong Shi; Bo Wang; Stephen R.Clarke; Jiang-Hua Sun

    2012-01-01

    Dendroctonus-fungus symbioses are often considered as the ideal model systems to study the development and maintenance ofectosymbioses,and diverse interactions,including antagonism,commensalism and mutualism,have been documented between these organisms.The red turpentine beetle,Dendroctonus valens LeConte (Coleoptera:Curculionidae:Scolytinae) is a pine-killing invasive beetle in northern China.Fungi species Ophiostoma minus,Leptographium sinoprocerum,L.terebrantis and L.procerum were associated with this bark beetle.Antagonistic interactions between D.valens and its associated fungi,such as O.minus and L.sinoprocerum,have been demonstrated,but the underlying causes of this phenomenon are unknown.Here,we first found the two tested fungi species retarded the net weight gain of D.valens larvae after completing 3-day feeding on their media.Furthermore,we provide direct evidence indicating the effect of associated fungi on the immunocompetence of D.valens larvae to explain the documented antagonism.Our results showed that the activity of phenoloxidase and total phenoloxidase in D.valens larvae were significantly upregulated by two strains of associated fungi,O.minus and L.sinoprocerum as compared with the controls.The phenoloxidase ratio increased significantly in the larvae which had fed for 3 days on media inoculated with O.minus.Because insect immune defenses are costly to be deployed,these results could be explored as one of the underlying mechanisms of the documented antagonism.

  18. An experimental demonstration of stem damage as a predictor of fire-caused mortality for ponderosa pine

    Science.gov (United States)

    van Mantgem, P.; Schwartz, M.

    2004-01-01

    We subjected 159 small ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) to treatments designed to test the relative importance of stem damage as a predictor of postfire mortality. The treatments consisted of a group with the basal bark artificially thinned, a second group with fuels removed from the base of the stem, and an untreated control. Following prescribed burning, crown scorch severity was equivalent among the groups. Postfire mortality was significantly less frequent in the fuels removal group than in the bark removal and control groups. No model of mortality for the fuels removal group was possible, because dead trees constituted ponderosa pine.

  19. Missing Peroxy Radical Sources within a Summertime Ponderosa Pine Forest

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, G. M.; Cantrell, Chris; Kim, S.; Mauldin, R. L.; Karl, Thomas G.; Harley, P.; Turnipseed, A.; Zheng, W.; Flocke, Frank M.; Apel, E. C.; Hornbrook, R. S.; Hall, S. R.; Ullmann, K.; Henry, S. B.; DiGangi, J. P.; Boyle, E. S.; Kaser, L.; Schnitzhofer, R.; Hansel, A.; Graus, M.; Nakashima, Yoshihiro; Kajii, Yoshizumi; Guenther, Alex B.; Keutsch, Frank N.

    2014-05-13

    Organic peroxy (RO2) and hydroperoxy (HO2) radicals are key intermediates in the photochemical processes that generate ozone, secondary organic aerosol and reactive nitrogen reservoirs throughout the troposphere. In regions with ample biogenic hydrocarbons, the richness and complexity of peroxy radical chemistry presents a significant challenge to current-generation models, especially given the scarcity of measurements in such environments. We present peroxy radical observations acquired within a Ponderosa pine forest during the summer 2010 Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen – Rocky Mountain Organic Carbon Study (BEACHON-ROCS). Total peroxy radical mixing ratios reach as high as 180 pptv and are among the highest yet recorded. Using the comprehensive measurement suite to constrain a near-explicit 0-D box model, we investigate the sources, sinks and distribution of peroxy radicals below the forest canopy. The base chemical mechanism underestimates total peroxy radicals by as much as a factor of 3. Peroxy radical sinks are unlikely to be overestimated, suggesting missing sources. A close comparison of model results with observations reveals at least two distinct source signatures. The first missing source, characterized by a sharp midday maximum and a strong dependence on solar radiation, is consistent with photolytic production of HO2. The diel profile of the second missing source peaks in the afternoon and suggests a process that generates RO2 independently of sun-driven photochemistry, such as ozonolysis of reactive hydrocarbons. The maximum magnitudes of these missing sources (~120 and 50 pptv min-1, respectively) are consistent with previous observations alluding to unexpectedly intense oxidation within the forest, and we conclude that a similar mechanism may underlie many such anomalous findings.

  20. Missing peroxy radical sources within a summertime ponderosa pine forest

    Science.gov (United States)

    Wolfe, G. M.; Cantrell, C.; Kim, S.; Mauldin, R. L., III; Karl, T.; Harley, P.; Turnipseed, A.; Zheng, W.; Flocke, F.; Apel, E. C.; Hornbrook, R. S.; Hall, S. R.; Ullmann, K.; Henry, S. B.; DiGangi, J. P.; Boyle, E. S.; Kaser, L.; Schnitzhofer, R.; Hansel, A.; Graus, M.; Nakashima, Y.; Kajii, Y.; Guenther, A.; Keutsch, F. N.

    2014-05-01

    Organic peroxy (RO2) and hydroperoxy (HO2) radicals are key intermediates in the photochemical processes that generate ozone, secondary organic aerosol and reactive nitrogen reservoirs throughout the troposphere. In regions with ample biogenic hydrocarbons, the richness and complexity of peroxy radical chemistry presents a significant challenge to current-generation models, especially given the scarcity of measurements in such environments. We present peroxy radical observations acquired within a ponderosa pine forest during the summer 2010 Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen - Rocky Mountain Organic Carbon Study (BEACHON-ROCS). Total peroxy radical mixing ratios reach as high as 180 pptv (parts per trillion by volume) and are among the highest yet recorded. Using the comprehensive measurement suite to constrain a near-explicit 0-D box model, we investigate the sources, sinks and distribution of peroxy radicals below the forest canopy. The base chemical mechanism underestimates total peroxy radicals by as much as a factor of 3. Since primary reaction partners for peroxy radicals are either measured (NO) or underpredicted (HO2 and RO2, i.e., self-reaction), missing sources are the most likely explanation for this result. A close comparison of model output with observations reveals at least two distinct source signatures. The first missing source, characterized by a sharp midday maximum and a strong dependence on solar radiation, is consistent with photolytic production of HO2. The diel profile of the second missing source peaks in the afternoon and suggests a process that generates RO2 independently of sun-driven photochemistry, such as ozonolysis of reactive hydrocarbons. The maximum magnitudes of these missing sources (~120 and 50 pptv min-1, respectively) are consistent with previous observations alluding to unexpectedly intense oxidation within forests. We conclude that a similar mechanism may underlie many

  1. Growth and physiological responses to varied environments among populations of Pinus ponderosa

    Science.gov (United States)

    Jianwei Zhang; Bert M. Cregg

    2005-01-01

    We investigated population responses in physiology, morphology, and growth of mature Pinus ponderosa trees to an environmental gradient across Nebraska, USA. Ten populations from western Nebraska and eastern Wyoming were grown in three 26-year-old provenance tests from the warmest and wettest site in the east (Plattsmouth) to the intermediate site in...

  2. Establishment, survival, and growth of selected browse species in a ponderosa pine forest

    Science.gov (United States)

    Dietz, D.R.; Uresk, D.W.; Messner, H.E.; McEwen, L.C.

    1980-01-01

    Information is presented on establishment, survival, and growth of seven selected browse species in a ponderosa pine forest over a 10-year period. Methods of establishment included hand seeding and planting bare-root and containerized stock. Success of different methods differed with shrub species.

  3. CARBON STORAGE AND FLUXES IN PONDEROSA PINE AT DIFFERENT SUCCESSIONAL STAGES

    Science.gov (United States)

    We compared carbon storage and fluxes in young and old ponderosa pine stands in Oregon, including plant and soil storage, net primary productivity, respiration fluxes, and eddy flux estimates of net ecosystem exchange. The young site (Y site) was previously an old-growth pondero...

  4. PARTITIONING OF WATER FLUX IN A SIERRA NEVADA PONDEROSA PINE PLANTATION. (R826601)

    Science.gov (United States)

    The weather patterns of the west side of the Sierra Nevada Mountains (cold, wet winters and hot, dry summers) strongly influence how water is partitioned between transpiration and evaporation and result in a specific strategy of water use by ponderosa pine trees (Pinus pond...

  5. ROOT GROWTH AND TURNOVER IN DIFFERENT AGED PONDEROSA PINE STANDS IN OREGON, USA

    Science.gov (United States)

    The impacts of pollution and climate change on soil carbon dynamics are poorly understood, in part due to a lack of information regarding root production and turnover in natural ecosystems. In order to examine how root dynamics change with stand age in ponderosa pine forests (...

  6. The geographic selection mosaic for ponderosa pine and crossbills: a tale of two squirrels.

    Science.gov (United States)

    Parchman, Thomas L; Benkman, Craig W

    2008-02-01

    Recent research demonstrates how the occurrence of a preemptive competitor (Tamiasciurus) gives rise to a geographic mosaic of coevolution for crossbills (Loxia) and conifers. We extend these studies by examining ponderosa pine (Pinus ponderosa), which produces more variable annual seed crops than the conifers in previous studies and often cooccurs with tree squirrels in the genus Sciurus that are less specialized than Tamiasciurus on conifer seed. We found no evidence of seed defenses evolving in response to selection exerted by S. aberti, which was apparently overwhelmed by selection resulting from inner bark feeding that caused many developing cones to be destroyed. In the absence of S. aberti, defenses directed at crossbills increased, favoring larger-billed crossbills and causing stronger reciprocal selection between crossbills and ponderosa pine. However, crossbill nomadism in response to cone crop fluctuations prevents localized reciprocal adaptation by crossbills. In contrast, evolution in response to S. griseus has incidentally defended cones against crossbills, limiting the geographic range of the interaction between crossbills and ponderosa pine. Our results suggest that annual resource variation does not prevent competitors from shaping selection mosaics, although such fluctuations likely prevent fine-scale geographic differentiation in predators that are nomadic in response to resource variability.

  7. Latent resilience in ponderosa pine forest: effects of resumed frequent fire.

    Science.gov (United States)

    Larson, Andrew J; Belote, R Travis; Cansler, C Alina; Parks, Sean A; Dietz, Matthew S

    2013-09-01

    Ecological systems often exhibit resilient states that are maintained through negative feedbacks. In ponderosa pine forests, fire historically represented the negative feedback mechanism that maintained ecosystem resilience; fire exclusion reduced that resilience, predisposing the transition to an alternative ecosystem state upon reintroduction of fire. We evaluated the effects of reintroduced frequent wildfire in unlogged, fire-excluded, ponderosa pine forest in the Bob Marshall Wilderness, Montana, USA. Initial reintroduction of fire in 2003 reduced tree density and consumed surface fuels, but also stimulated establishment of a dense cohort of lodgepole pine, maintaining a trajectory toward an alternative state. Resumption of a frequent fire regime by a second fire in 2011 restored a low-density forest dominated by large-diameter ponderosa pine by eliminating many regenerating lodgepole pines and by continuing to remove surface fuels and small-diameter lodgepole pine and Douglas-fir that established during the fire suppression era. Our data demonstrate that some unlogged, fire-excluded, ponderosa pine forests possess latent resilience to reintroduced fire. A passive model of simply allowing lightning-ignited fires to burn appears to be a viable approach to restoration of such forests.

  8. Restoring forest structure and process stabilizes forest carbon in wildfire-prone southwestern ponderosa pine forests

    Science.gov (United States)

    Matthew D. Hurteau; Shuang Liang; Katherine L. Martin; Malcolm P. North; George W. Koch; Bruce A. Hungate

    2016-01-01

    Changing climate and a legacy of fire-exclusion have increased the probability of high-severity wildfire, leading to an increased risk of forest carbon loss in ponderosa pine forests in the southwestern USA. Efforts to reduce high-severity fire risk through forest thinning and prescribed burning require both the removal and emission of carbon from these forests, and...

  9. Response of dwarf mistletoe-infested ponderosa pine to thinning: 2. Dwarf mistletoe propagation.

    Science.gov (United States)

    Lewis F. Roth; James W. Barrett

    1985-01-01

    Propagation of dwarf mistletoe in ponderosa pine saplings is little influenced by thinning overly dense stands to 250 trees per acre. Numerous plants that appear soon after thinning develop from formerly latent plants in the suppressed under-story. Subsequently, dwarf mistletoe propagates nearly as fast as tree crowns enlarge but the rate differs widely among trees....

  10. Mountain pine beetle attack in ponderosa pine: Comparing methods for rating susceptibility

    Science.gov (United States)

    David C. Chojnacky; Barbara J. Bentz; Jesse A. Logan

    2000-01-01

    Two empirical methods for rating susceptibility of mountain pine beetle attack in ponderosa pine were evaluated. The methods were compared to stand data modeled to objectively rate each sampled stand for susceptibly to bark-beetle attack. Data on bark-beetle attacks, from a survey of 45 sites throughout the Colorado Plateau, were modeled using logistic regression to...

  11. Modeling snag dynamics in northern Arizona mixed-conifer and ponderosa pine forests

    Science.gov (United States)

    Joseph L. Ganey; Scott C. Vojta

    2007-01-01

    Snags (standing dead trees) are important components of forested habitats that contribute to ecological decay and recycling processes as well as providing habitat for many life forms. As such, snags are of special interest to land managers, but information on dynamics of snag populations is lacking. We modeled trends in snag populations in mixed-conifer and ponderosa...

  12. Tall oil precursors in three western pines: ponderosa, lodgepole, and limber pine

    Energy Technology Data Exchange (ETDEWEB)

    Conner, A.H.; Diehl, M.A.; Rowe, J.W.

    1980-01-01

    The nonvolatile diethyl ether extracts (NVEE) from ponderosa, lodgepole, and limber pines were analyzed to determine the amounts and chemical composition of the tall oil precursors (resin acids, fatty acids, and nonsaponifiables) and turpentine precursors available from these species. The results showed that crude tall oil compositions would be approximately as follows (% resin acids, % fatty acids, % nonsaponifiables); ponderosa pine - sapwood (15, 75, 10), heartwood (78, 7, 15); lodgepole pine - sapwood (24, 57, 19), heartwood (51, 26, 23); limber pine - sapwood (10, 82, 8), heartwood (23, 60, 17). The larger nonsaponifiables content, as compared to southern pines, is the major factor in explaining the greater difficulty in the distillative refining of tall oil from these western species. Eight resin acids were found in ponderosa and lodgepole pine: palustric, isopimaric, abietic, dehydroabietic, and neoabietic acids predominated. Seven resin acids were identified from limber pine: anticopalic, isopimaric, abietic, and dehydroabietic acids predominated. The free and esterfied fatty acids from these species contained predominantly oleic and linoleic acids. In addition limber pine contained major amounts of 5, 9, 12-octadecatrienoic acid. The nonsaponifiables contained mostly diterpenes and the sterols, sitosterol and campesterol. The major turpentine components were: ponderosa pine - ..beta..-pinene and 3-carene; lodgepole pine - ..beta..-phellandrene; and limber pine - 3-carene, ..beta..-phellandrene, ..cap alpha..-piene, and ..beta..-pinene.

  13. Developing resilient ponderosa pine forests with mechanical thinning and prescribed fire in central Oregon's pumice region

    Science.gov (United States)

    Matt D. Busse; P.H. Cochran; William E. Hopkins; William H. Johnson; Gregg M. Riegel; Gary O. Fiddler; Alice W. Ratcliff; Carol J. Shestak

    2009-01-01

    Thinning and prescribed burning are common management practices for reducing fuel buildup in ponderosa pine forests. However, it is not well understood if their combined use is required to lower wildfire risk and to help restore natural ecological function. We compared 16 treatment combinations of thinning, prescribed fire, and slash retention for two decades...

  14. Classification tree and minimum-volume ellipsoid analyses of the distribution of ponderosa pine in the western USA

    Science.gov (United States)

    Norris, Jodi R.; Jackson, Stephen T.; Betancourt, Julio L.

    2006-01-01

    Aim? Ponderosa pine (Pinus ponderosa Douglas ex Lawson & C. Lawson) is an economically and ecologically important conifer that has a wide geographic range in the western USA, but is mostly absent from the geographic centre of its distribution - the Great Basin and adjoining mountain ranges. Much of its modern range was achieved by migration of geographically distinct Sierra Nevada (P. ponderosa var. ponderosa) and Rocky Mountain (P. ponderosa var. scopulorum) varieties in the last 10,000 years. Previous research has confirmed genetic differences between the two varieties, and measurable genetic exchange occurs where their ranges now overlap in western Montana. A variety of approaches in bioclimatic modelling is required to explore the ecological differences between these varieties and their implications for historical biogeography and impending changes in western landscapes. Location? Western USA. Methods? We used a classification tree analysis and a minimum-volume ellipsoid as models to explain the broad patterns of distribution of ponderosa pine in modern environments using climatic and edaphic variables. Most biogeographical modelling assumes that the target group represents a single, ecologically uniform taxonomic population. Classification tree analysis does not require this assumption because it allows the creation of pathways that predict multiple positive and negative outcomes. Thus, classification tree analysis can be used to test the ecological uniformity of the species. In addition, a multidimensional ellipsoid was constructed to describe the niche of each variety of ponderosa pine, and distances from the niche were calculated and mapped on a 4-km grid for each ecological variable. Results? The resulting classification tree identified three dominant pathways predicting ponderosa pine presence. Two of these three pathways correspond roughly to the distribution of var. ponderosa, and the third pathway generally corresponds to the distribution of var

  15. Influence of Starvation on the Structure of Gut-Associated Bacterial Communities in the Chinese White Pine Beetle (Dendroctonus armandi

    Directory of Open Access Journals (Sweden)

    Xia Hu

    2016-06-01

    Full Text Available This study investigated the influence of starvation on the structure of the gut bacterial community in the Chinese white pine beetle (Dendroctonus armandi. A total of 14 operational taxonomic units (OTUs0.03 clusters belonging to nine genera were identified. Denaturing gradient gel electrophoresis (DGGE profiles of bacterial PCR-amplified 16S rRNA gene fragments from the guts of starved male and female adults revealed that the bacterial community diversity increased after starvation. The dominant genus Citrobacter decreased significantly, whereas the genus Serratia increased in both starved female and starved male adults. The most predominant bacterial genus in D. armandi adults was Citrobacter, except for starved male adults, in which Serratia was the most abundant genus (27%. Our findings reveal that starvation affects gut bacterial dynamics in D. armandi, as has been observed in other insect species.

  16. Physiological responses of ponderosa pine in western Montana to thinning, prescribed fire and burning season.

    Science.gov (United States)

    Sala, Anna; Peters, Gregory D; McIntyre, Lorna R; Harrington, Michael G

    2005-03-01

    Low-elevation ponderosa pine (Pinus ponderosa Dougl. ex. Laws.) forests of the northern Rocky Mountains historically experienced frequent low-intensity fires that maintained open uneven-aged stands. A century of fire exclusion has contributed to denser ponderosa pine forests with greater competition for resources, higher tree stress and greater risk of insect attack and stand-destroying fire. Active management intended to restore a semblance of the more sustainable historic stand structure and composition includes selective thinning and prescribed fire. However, little is known about the relative effects of these management practices on the physiological performance of ponderosa pine. We measured soil water and nitrogen availability, physiological performance and wood radial increment of second growth ponderosa pine trees at the Lick Creek Experimental Site in the Bitterroot National Forest, Montana, 8 and 9 years after the application of four treatments: thinning only; thinning followed by prescribed fire in the spring; thinning followed by prescribed fire in the fall; and untreated controls. Volumetric soil water content and resin capsule ammonium did not differ among treatments. Resin capsule nitrate in the control treatment was similar to that in all other treatments, although burned treatments had lower nitrate relative to the thinned-only treatment. Trees of similar size and canopy condition in the three thinned treatments (with and without fire) displayed higher leaf-area-based photosynthetic rate, stomatal conductance and mid-morning leaf water potential in June and July, and higher wood radial increment relative to trees in control units. Specific leaf area, mass-based leaf nitrogen content and carbon isotope discrimination did not vary among treatments. Our results suggest that, despite minimal differences in soil resource availability, trees in managed units where basal area was reduced had improved gas exchange and growth compared with trees in

  17. 进口北美原木山松大小蠹风险分析及检疫管理对策%Risk Analysis and Quarantine Management Countermeasures of Dendroctonus ponderosae Hopkins in Imported Log from North America

    Institute of Scientific and Technical Information of China (English)

    郑茂灿; 叶剑雄; 林玲

    2011-01-01

    通过对山松大小蠹随北美原木进口进入我国传入、定殖、扩散风险以及经济重要性进行风险分析,并提出防范该虫随进口北美原木传入我国的检疫管理对策.

  18. Photosynthetic acclimation to enriched CO{sub 2} concentrations in Pinus Ponderosa

    Energy Technology Data Exchange (ETDEWEB)

    Torres, M.P. [California State Univ., Humbolt, CA (United States)

    1995-11-01

    By the middle of the 21st century earth`s ambient CO{sub 2} level is expected to increase two-fold ({approximately}350 umol/L). Higher levels of CO{sub 2} are expected to cause major changes in the morphological, physiological, and biochemical traits of the world`s vegetation. Therefore, we constructed an experiment designed to measure the long-term acclimation processes of Pinus Ponderosa. As a prominent forest conifer, Pinus Ponderosa is useful when assessing a large scale global carbon budget. Eighteen genetically variable families were exposed to 3 different levels of CO{sub 2} (350 umol/L, 525 umol/L, 700 umol/L), for three years. Acclimation responses were quantified by assays of photosynthetic rate, chlorophyll fluorescence, and chlorophyll pigment concentrations.

  19. Soil Type Affects Pinus ponderosa var. scopulorum (Pinaceae Seedling Growth in Simulated Drought Experiments

    Directory of Open Access Journals (Sweden)

    Alexander J. Lindsey

    2013-07-01

    Full Text Available Premise of the study: Effects of drought stress and media type interactions on growth of Pinus ponderosa var. scopulorum germinants were investigated. Methods and Results: Soil properties and growth responses under drought were compared across four growth media types: two native soils (dolomitic limestone and granite, a soil-less industry standard conifer medium, and a custom-mixed conifer medium. After 35 d of growth, the seedlings under drought stress (reduced watering produced less shoot and root biomass than watered control seedlings. Organic media led to decreased root biomass, but increased root length and shoot biomass relative to the mineral soils. Conclusions: Media type affected root-to-shoot biomass partitioning of P. ponderosa var. scopulorum, which may influence net photosynthetic rates, growth, and long-term seedling survival. Further work should examine how specific soil properties like bulk density and organic matter influence biomass allocation in greenhouse studies.

  20. Trapping effect and sex pheromone prescription of Dendroctonus valens, Leconte%红脂大小蠹信息素配方研究及诱杀效果

    Institute of Scientific and Technical Information of China (English)

    郭玉永; 吴国礼; 刘伟国; 苗振旺

    2003-01-01

    2002年5月、6月,在关帝林区西葫芦林场、三道川林场分别进行了红脂大小蠹(Dendroctonus valens,Leconte)信息素配方、诱杀时间及诱杀效果试验.结果表明:5月中旬到6月中旬为最佳诱杀时期;使用β-蒎烯:α-蒎烯:3-蒈烯为1:1:1配方的信息素进行大面积诱杀,林木被害率下降64.4%,平均侵入孔数下降59.2%;红脂大小蠹(Dendroctonus valens,Leconte)信息素成份以β-蒎烯:α-蒎烯:3-蒈烯为1:1:3或全部是3-蒈烯的两种配方为最佳配方;使用信息素诱杀红脂大小蠹(Dendroctonus valens,Leconte)平均每667 m2投资5.5元,省工省时防效好,可大面积推广应用.

  1. Species richness and soil properties in Pinus ponderosa forests: A structural equation modeling analysis

    Science.gov (United States)

    Laughlin, D.C.; Abella, S.R.; Covington, W.W.; Grace, J.B.

    2007-01-01

    Question: How are the effects of mineral soil properties on understory plant species richness propagated through a network of processes involving the forest overstory, soil organic matter, soil nitrogen, and understory plant abundance? Location: North-central Arizona, USA. Methods: We sampled 75 0.05-ha plots across a broad soil gradient in a Pinus ponderosa (ponderosa pine) forest ecosystem. We evaluated multivariate models of plant species richness using structural equation modeling. Results: Richness was highest at intermediate levels of understory plant cover, suggesting that both colonization success and competitive exclusion can limit richness in this system. We did not detect a reciprocal positive effect of richness on plant cover. Richness was strongly related to soil nitrogen in the model, with evidence for both a direct negative effect and an indirect non-linear relationship mediated through understory plant cover. Soil organic matter appeared to have a positive influence on understory richness that was independent of soil nitrogen. Richness was lowest where the forest overstory was densest, which can be explained through indirect effects on soil organic matter, soil nitrogen and understory cover. Finally, model results suggest a variety of direct and indirect processes whereby mineral soil properties can influence richness. Conclusions: Understory plant species richness and plant cover in P. ponderosa forests appear to be significantly influenced by soil organic matter and nitrogen, which are, in turn, related to overstory density and composition and mineral soil properties. Thus, soil properties can impose direct and indirect constraints on local species diversity in ponderosa pine forests. ?? IAVS; Opulus Press.

  2. The cold-hardiness of Dendroctonus valens (Coleoptera, Scolytidae) and Rhizophagus grandis (Coleoptera, Rhizophagidae)%红脂大小蠹Dendroctonus valens(Coleoptera,Scolytidae)和大唼蜡甲 Rhizophagus grandis(Coleoptera,Rhizophagidae)的耐寒性

    Institute of Scientific and Technical Information of China (English)

    赵建兴; 杨忠岐; Jean-Claude Gregoire

    2009-01-01

    Dendroctonus valens LeConte(Red turpentine beetle,RTB) was recently found in outbreak in China.Its elder instars and mature larvae mainly over-winter under the roots of the pine stumps and standing trees in China.The cold tolerant capabilities of the pest was estimated in the laboratory by SU-per-cooling points (SCP) and short-term lower lethal temperatures (LLT).The results show that the lowest mean super-cooling point of the RTB over-wintering larvae is-11.98 ± 2.55℃ and it is a species of tolerant-freezing insect.The SCP of RTB is significantly different between different geographical populations,the elder stage larvae have lower cold-hardiness than younger ones,but no significantly different between the larvae in early winter and later winter.The RTB larvae could spend its life in winter below the atmospheric temperie temperature which being lower more than-23.5℃ at least.In contrast,Rhizophagus grandis Gyll.,as a predator of Dendroctonus micans,was introduced to China against RTB since 2001.The mean SCP of Rhizophagus grandis larva is-l8.05 ±2.76℃ which being lower temperature more than ones of any stage of RTB.%红脂大小蠹 Dendroctonus valens LeConte (Red turpentine beetle,RTB)是近年来在中国爆发的入侵生物,在我国主要以老熟幼虫在油松伐桩和立木的根部越冬.室内测定昆虫的过冷却点(SCP)和短时间致死低温(LLT)是评价昆虫耐寒能力的重要方法.实验结果显示,红脂大小蠹越冬幼虫的平均过冷却点为一11.98±2.55℃,是一种耐冰冻的昆虫.红脂大小蠹的过冷却点在不同地理分布区的种群问有明显差异,老熟幼虫的过冷却点明显低于低龄幼虫,在越冬前和越冬后的幼虫问没有明显差异.红脂大小蠹幼虫在冬季至少町以忍受-23.5℃的大气温度安全越冬.从2001年开始引入我国的云杉大小蠹的捕食者大唼蜡甲(Rhizophagus grandis cyll.)幼虫的过冷却点为-18.05±2.76℃,低于红脂大小蠹所有虫态

  3. Importance of resin ducts in reducing ponderosa pine mortality from bark beetle attack.

    Science.gov (United States)

    Kane, Jeffrey M; Kolb, Thomas E

    2010-11-01

    The relative importance of growth and defense to tree mortality during drought and bark beetle attacks is poorly understood. We addressed this issue by comparing growth and defense characteristics between 25 pairs of ponderosa pine (Pinus ponderosa) trees that survived and trees that died from drought-associated bark beetle attacks in forests of northern Arizona, USA. The three major findings of our research were: (1) xylem resin ducts in live trees were >10% larger (diameter), >25% denser (no. of resin ducts mm(-2)), and composed >50% more area per unit ring growth than dead trees; (2) measures of defense, such as resin duct production (no. of resin ducts year(-1)) and the proportion of xylem ring area to resin ducts, not growth, were the best model parameters of ponderosa pine mortality; and (3) most correlations between annual variation in growth and resin duct characteristics were positive suggesting that conditions conducive to growth also increase resin duct production. Our results suggest that trees that survive drought and subsequent bark beetle attacks invest more carbon in resin defense than trees that die, and that carbon allocation to resin ducts is a more important determinant of tree mortality than allocation to radial growth.

  4. Limited response of ponderosa pine bole defenses to wounding and fungi.

    Science.gov (United States)

    Gaylord, Monica L; Hofstetter, Richard W; Kolb, Thomas E; Wagner, Michael R

    2011-04-01

    Tree defense against bark beetles (Curculionidae: Scolytinae) and their associated fungi generally comprises some combination of constitutive (primary) and induced (secondary) defenses. In pines, the primary constitutive defense against bark beetles consists of preformed resin stored in resin ducts. Induced defenses at the wound site (point of beetle entry) in pines may consist of an increase in resin flow and necrotic lesion formation. The quantity and quality of both induced and constitutive defenses can vary by species and season. The inducible defense response in ponderosa pine is not well understood. Our study examined the inducible defense response in ponderosa pine using traumatic mechanical wounding, and wounding with and without fungal inoculations with two different bark beetle-associated fungi (Ophiostoma minus and Grosmannia clavigera). Resin flow did not significantly increase in response to any treatment. In addition, necrotic lesion formation on the bole after fungal inoculation was minimal. Stand thinning, which has been shown to increase water availability, had no, or inconsistent, effects on inducible tree defense. Our results suggest that ponderosa pine bole defense against bark beetles and their associated fungi is primarily constitutive and not induced.

  5. Microanalysis characterization of bioactive protein-bound polysaccharides produced by Amanita ponderosa cultures.

    Science.gov (United States)

    Salvador, Cátia; Martins, M Rosário; Caldeira, A Teresa

    2015-02-01

    Different compounds of edible mushrooms are responsible for their bioactivity. The ability to synthesize polysaccharides, namely protein-polysaccharide (PPS) complexes, is related to the antioxidant capacity of these compounds and present great interest in preventing a number of diseases, including cancer, cardiovascular and auto-immune diseases, and accelerated aging. Amanita ponderosa are wild edible mushrooms that grow in Mediterranean "montado" areas [Portuguese name given to cork oak (Quercus suber) and holm oak (Quercus ilex) forests]. The aim of this study was to evaluate the production of PPS complexes obtained from A. ponderosa cultures using a new microanalytical approach to quickly and easily monitor the production process. Microanalysis using Fourier-transform infrared using attenuated total reflection and Raman spectroscopy of PPS samples showed spectra compatible with identification of this type of compound in culture extracts. PPS separated by size-exclusion chromatography showed seven main complexes. Molecular weights of the main PPS complexes isolated from cultures ranged between 1.5 and 20 kDa and did not present toxicity against Artemia salina, demonstrating the potential of A. ponderosa as a source of biologically active compounds with nutraceutical value. Application of this microanalytical approach to monitoring the production of PPS compounds can be successfully applied in biotechnological processes.

  6. Structural injury underlying mottling in ponderosa pine needles exposed to ambient ozone concentrations in the San Bernardino Mountains near Los Angeles, California

    Science.gov (United States)

    Pierre Vollenweider; Mark E. Fenn; Terry Menard; Madeleine Gunthardt-Goerg; Andrzej Bytnerowicz

    2013-01-01

    For several decades, southern California experienced the worst ozone pollution ever reported. Peak ozone concentrations have, however, declined steadily since 1980. In this study, the structural injuries underlying ozone symptoms in needles of ponderosa pine (Pinus ponderosa Dougl. ex Laws.) collected in summer 2006 from one of the most polluted sites in the San...

  7. 87Sr/86Sr sourcing of ponderosa pine used in Anasazi great house construction at Chaco Canyon, New Mexico

    Science.gov (United States)

    Reynolds, Amanda C.; Betancourt, Julio L.; Quade, Jay; Patchett, P. Jonathan; Dean, Jeffery S.; Stein, John

    2005-01-01

    Previous analysis of 87Sr/86Sr ratios shows that 10th through 12th century Chaco Canyon was provisioned with plant materials that came from more than 75 km away. This includes (1) corn (Zea mays) grown on the eastern flanks of the Chuska Mountains and floodplain of the San Juan River to the west and north, and (2) spruce (Picea sp.) and fir (Abies sp.) beams from the crest of the Chuska and San Mateo Mountains to the west and south. Here, we extend 87Sr/86Sr analysis to ponderosa pine (Pinus ponderosa) prevalent in the architectural timber at three of the Chacoan great houses (Pueblo Bonito, Chetro Ketl, Pueblo del Arroyo). Like the architectural spruce and fir, much of the ponderosa matches the 87Sr/86Sr ratios of living trees in the Chuska Mountains. Many of the architectural ponderosa, however, have similar ratios to living trees in the La Plata and San Juan Mountains to the north and Lobo Mesa/Hosta Butte to the south. There are no systematic patterns in spruce/fir or ponderosa provenance by great house or time, suggesting the use of stockpiles from a few preferred sources. The multiple and distant sources for food and timber, now based on hundreds of isotopic values from modern and archeological samples, confirm conventional wisdom about the geographic scope of the larger Chacoan system. The complexity of this procurement warns against simple generalizations based on just one species, a single class of botanical artifact, or a few isotopic values.

  8. Overstory Tree Mortality in Ponderosa Pine and Spruce-Fir Ecosystems Following a Drought in Northern New Mexico

    Directory of Open Access Journals (Sweden)

    Brian P. Oswald

    2016-10-01

    Full Text Available Drought-caused tree dieback is an issue around the world as climates change and many areas become dryer and hotter. A drought from 1998–2004 resulted in a significant tree dieback event in many of the wooded areas in portions of the Jemez Mountains and the adjacent Pajarito Plateau in northern New Mexico. The objectives of this study were to evaluate and quantify the differences in tree mortality before and after a recent drought in ponderosa pine and spruce-fir ecosystems, and to assess the effect of mechanical thinning on ponderosa pine mortality. Significant increases in mortality were observed in the unthinned ponderosa pine ecosystem. Mortality varied significantly between species and within size classes. Mechanical thinning of ponderosa pines reduced overstory mortality to non-significant levels. A lack of rainfall, snowfall, and increases in daily minimum temperature contributed most to the mortality. Adaptive management, including the use of thinning activities, appear to moderate the impact of climate change on ponderosa pine forests in this region, increasing the long-term health of the ecosystem. The impact of climate change on the spruce-fir ecosystems may accelerate successional changes.

  9. Pine Defensive Monoterpene α-Pinene Influences the Feeding Behavior of Dendroctonus valens and Its Gut Bacterial Community Structure

    Directory of Open Access Journals (Sweden)

    Letian Xu

    2016-11-01

    Full Text Available The exposure to plant defense chemicals has negative effects on insect feeding activity and modifies insect gut microbial community composition. Dendroctonus valens is a very destructive forest pest in China, and harbors a large diversity and abundance of gut microorganisms. Host pine defensive chemicals can protect the pines from attack by the holobiont. In this study, boring length of D. valens feeding on 0 mg/g α-pinene and 9 mg/g α-pinene concentration in phloem media for 6 and 48 h were recorded, and their gut bacterial communities were analyzed in parallel. Nine milligram per gram α-pinene concentration significantly inhibited boring length of D. valens and altered its gut microbial community structure after 6 h. The inhibition of boring length from 9 mg/g α-pinene in diets ceased after 48 h. No significant differences of the bacterial communities were observed between the beetles in 0 and 9 mg/g α-pinene concentration in phloem media after 48 h. Our results showed that the inhibition of the feeding behavior of D. valens and the disturbance to its gut bacterial communities in 9 mg/g α-pinene concentration in phloem media after 6 h were eliminated after 48 h. The resilience of gut bacterial community of D. valens may help the beetle catabolize pine defense chemical.

  10. Factors influencing the geographical distribution of Dendroctonus rhizophagus (Coleoptera: Curculionidae: Scolytinae) in the Sierra Madre Occidental, México.

    Science.gov (United States)

    Mendoza, Ma Guadalupe; Salinas-Moreno, Yolanda; Olivo-Martínez, Antonio; Zúñiga, Gerardo

    2011-06-01

    The bark beetle, Dendroctonus rhizophagus Thomas & Bright, is endemic to the Sierra Madre Occidental (SMOC) in México. This bark beetle is a major pest of the seedlings and young saplings of several pine species that are of prime importance to the nation's forest industry. Despite the significance of this bark beetle as a pest, its biology, ecology, and distribution are poorly known. Three predictive modeling approaches were used as a first approximation to identify bioclimatic variables related to the presence of D. rhizophagus in the SMOC and to obtain maps of its potential distribution within the SMOC, which is a morphotectonic province. Our results suggest that the bark beetle could have an almost continuous distribution throughout the major mountain ranges of the SMOC. This beetle has a relatively narrow ecological niche with respect to some temperature and precipitation variables and inhabits areas with climatic conditions that are unique from those usually prevalent in the SMOC. However, the bark beetle has a broad ecological niche with respect to the number of hosts that it attacks. At the macro-scale level, the D. rhizophagus distribution occurs within the wider distribution of its main hosts. The limit of the geographical distribution of this bark beetle coincides with the maximum temperature isotherms. Our results imply a preference for temperate habitats, which leads to the hypothesis that even minor changes in climate may have significant effects on its distribution and abundance.

  11. Morphology of the Male Reproductive System and Spermiogenesis of Dendroctonus armandi Tsai and Li (Coleoptera: Curculionidae: Scolytinae).

    Science.gov (United States)

    Wu, Yi-Fei; Wei, Lu-Sha; Anthony Torres, Mark; Zhang, Xu; Wu, Shao-Ping; Chen, Hui

    2017-01-01

    Studying the reproductive attributes of pests is central to understanding their life cycle history and in crafting management strategies to regulate, if not bring down, their population below threshold levels. In this article, the morphology of the male reproductive tract, topology of the spermatozoa, and salient features of spermiogenesis in the Chinese white pine beetle, Dendroctonus armandi Tsai and Li was studied to provide baseline information for further pest management studies. Results showed that male reproductive tract of this species differs from those documented in other Coleopterans by having 20 testicular tubules in each testis and the presence of two types of accessory glands. The spermatozoon is seen having peculiar characteristics such as an "h"-shaped acrosomal vesicle with a "puff"-like expansion, one centriole, one large spongy body, and two accessory bodies. Despite with some morphological differences of the male reproductive organ, spermatogenesis in this organism is similar to other Coleopterans. Overall, detailed studies regarding the components of the primary male reproductive organ of this beetle species would expand the knowledge on the less-understood biology of Coleopteran pests and would help in designing regulatory measures to conserve endemic and indigenous pine trees in China. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  12. Cytochrome P450 complement (CYPome) of Candida oregonensis, a gut-associated yeast of bark beetle, Dendroctonus rhizophagus.

    Science.gov (United States)

    Hernández-Martínez, Fabiola; Briones-Roblero, Carlos Iván; Nelson, David R; Rivera-Orduña, Flor Nohemí; Zúñiga, Gerardo

    2016-09-01

    Bark beetles (Curculionidae: Scolytinae) and associated microorganisms must overcome a complex tree's defence system, which includes toxic monoterpenes, to successfully complete their life cycle. A number of studies have suggested these microorganisms could have ecological roles related with the nutrition, detoxification, and semiochemical production. In particular, in filamentous fungi symbionts, cytochrome P450 (CYP) have been involved with terpenoid detoxification and biotransformation processes. Candida oregonensis has been isolated from the gut, ovaries, and frass of different bark beetle species, and it is a dominant species in the Dendroctonus rhizophagus gut. In this study, we identify, characterise, and infer the phylogenetic relationships of C. oregonensis CYP genes. The results indicate that the cytochrome P450 complement (CYPome) is composed of nine genes (CYP51F1, CYP61A1, CYP56D1, CYP52A59, CYP52A60, CYP52A61, CYP52A62, CYP5217A8, and CYP5217B1), which might participate in primary metabolic reactions such as sterol biosynthesis, biodegradation of xenobiotic, and resistance to environmental stress. The prediction of the cellular location suggests that these CYPs to be anchored to the plasma membrane, membranes of the endoplasmic reticulum, mitochondria, and peroxisomes. These findings lay the foundation for future studies about the functional role of P450s, not only for yeasts, but also for the insects with which they interact. Copyright © 2016 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  13. Pine Defensive Monoterpene α-Pinene Influences the Feeding Behavior of Dendroctonus valens and Its Gut Bacterial Community Structure.

    Science.gov (United States)

    Xu, Letian; Shi, Zhanghong; Wang, Bo; Lu, Min; Sun, Jianghua

    2016-11-01

    The exposure to plant defense chemicals has negative effects on insect feeding activity and modifies insect gut microbial community composition. Dendroctonus valens is a very destructive forest pest in China, and harbors a large diversity and abundance of gut microorganisms. Host pine defensive chemicals can protect the pines from attack by the holobiont. In this study, boring length of D. valens feeding on 0 mg/g α-pinene and 9 mg/g α-pinene concentration in phloem media for 6 and 48 h were recorded, and their gut bacterial communities were analyzed in parallel. Nine milligram per gram α-pinene concentration significantly inhibited boring length of D. valens and altered its gut microbial community structure after 6 h. The inhibition of boring length from 9 mg/g α-pinene in diets ceased after 48 h. No significant differences of the bacterial communities were observed between the beetles in 0 and 9 mg/g α-pinene concentration in phloem media after 48 h. Our results showed that the inhibition of the feeding behavior of D. valens and the disturbance to its gut bacterial communities in 9 mg/g α-pinene concentration in phloem media after 6 h were eliminated after 48 h. The resilience of gut bacterial community of D. valens may help the beetle catabolize pine defense chemical.

  14. Temperature alters the relative abundance and population growth rates of species within the Dendroctonus frontalis (Coleoptera: Curculionidae) community.

    Science.gov (United States)

    Evans, L M; Hofstetter, R W; Ayres, M P; Klepzig, K D

    2011-08-01

    Temperature has strong effects on metabolic processes of individuals and demographics of populations, but effects on ecological communities are not well known. Many economically and ecologically important pest species have obligate associations with other organisms; therefore, effects of temperature on these species might be mediated by strong interactions. The southern pine beetle (Dendroctonus frontalis Zimmermann) harbors a rich community of phoretic mites and fungi that are linked by many strong direct and indirect interactions, providing multiple pathways for temperature to affect the system. We tested the effects of temperature on this community by manipulating communities within naturally infested sections of pine trees. Direct effects of temperature on component species were conspicuous and sometimes predictable based on single-species physiology, but there were also strong indirect effects of temperature via alteration of species interactions that could not have been predicted based on autecological temperature responses. Climatic variation, including directional warming, will likely influence ecological systems through direct physiological effects as well as indirect effects through species interactions.

  15. Community structure of gut fungi during different developmental stages of the Chinese white pine beetle (Dendroctonus armandi).

    Science.gov (United States)

    Hu, Xia; Li, Ming; Chen, Hui

    2015-02-12

    The Chinese white pine beetle is arguably the most destructive forest insect in the Qinling Mountains in Northern China. Little is known about the structure of the fungal communities associated with Dendroctonus armandi, even though this wood-boring insect plays important roles in ecosystem and biological invasion processes that result in huge economic losses in pine forests. The aim of this study was to investigate the fungal community structure present in the galleries and guts of D. armandi at different developmental stages using PCR-denaturing gradient gel electrophoresis (DGGE). Analysis of PCR-amplified 18S rRNA gene fragments of fungi from the guts of D. armandi revealed fungal communities of low complexity that differed according to the developmental stage. Yeast of the genus Candida and the filamentous fungi Ophiostoma predominated in D. armandi and its galleries. In particular, Candida accounted for 56% of the fungal community in the pupal stage. Characterizing the evolution and content of the intestinal microbial community structure in D. armandi may facilitate the development of new pest control strategies.

  16. Differences in the structure of the gut bacteria communities in development stages of the Chinese white pine beetle (Dendroctonus armandi).

    Science.gov (United States)

    Hu, Xia; Wang, Chunyan; Chen, Hui; Ma, Junning

    2013-10-18

    The Chinese white pine beetle Dendroctonus armandi Tsai and Li, is arguably the most destructive forest insect in the Qinling Mountains in Northern China. Little is known about the structure of the bacterial communities associated with D. armandi even though this wood-boring insect plays important roles in ecosystem and biological invasion processes that result in huge economic losses in pine forests. The aim of this study was to investigate the composition of the bacterial communities present in the guts of D. armandi at different developmental stages using a culture-independent method involving PCR-denaturing gradient gel electrophoresis (DGGE). Analysis of PCR-amplified 16S rRNA gene fragments of bacteria from the guts of larvae, pupae, and male and female adults revealed bacterial communities of low complexity that differed according to the developmental stage. Citrobacter spp. and Pantoea spp. predominated in larvae and adults, whereas Methylobacterium was the dominant genus at the pupal stage. The main difference between the guts of male and female adults was the greater dominance of Citrobacter in females. Previous studies suggest that the bacterial community associated with D. armandi guts may influence insect development. The data obtained in this study regarding the phylogenetic relationships and the community structure of intestinal bacteria at different developmental stages of the D. armandi life cycle contribute to our understanding of D. armandi and could aid the development of new pest control strategies.

  17. 华山松大小蠹化学信息物质%Semiochemicals of Dendroctonus armandi

    Institute of Scientific and Technical Information of China (English)

    谢寿安; 丁彦

    2010-01-01

    在常温下(25℃)解剖华山松大小蠹(Dendroctonus armandi Tsai et Li)的雌、雄虫,以正己烷为溶剂提取华山松大小蠹的后肠和粪便挥发物,并进行GC-MS分析.结果表明:在室温状态下,雌虫后肠挥发物中含有23种物质,主要为萜酸类、萜烯类、雌雄甾类、醇类和醛类等;雄虫后肠中有25种,以有机酸(树脂型萜酸居多)、酯类化合物和萜烯类化合物为其主要成分;粪便中有33种,树脂型的萜酸最多.华山松大小蠹的化学活性物质以萜类化合物为主.

  18. Differences in the Structure of the Gut Bacteria Communities in Development Stages of the Chinese White Pine Beetle (Dendroctonus armandi

    Directory of Open Access Journals (Sweden)

    Junning Ma

    2013-10-01

    Full Text Available The Chinese white pine beetle Dendroctonus armandi Tsai and Li, is arguably the most destructive forest insect in the Qinling Mountains in Northern China. Little is known about the structure of the bacterial communities associated with D. armandi even though this wood-boring insect plays important roles in ecosystem and biological invasion processes that result in huge economic losses in pine forests. The aim of this study was to investigate the composition of the bacterial communities present in the guts of D. armandi at different developmental stages using a culture-independent method involving PCR-denaturing gradient gel electrophoresis (DGGE. Analysis of PCR-amplified 16S rRNA gene fragments of bacteria from the guts of larvae, pupae, and male and female adults revealed bacterial communities of low complexity that differed according to the developmental stage. Citrobacter spp. and Pantoea spp. predominated in larvae and adults, whereas Methylobacterium was the dominant genus at the pupal stage. The main difference between the guts of male and female adults was the greater dominance of Citrobacter in females. Previous studies suggest that the bacterial community associated with D. armandi guts may influence insect development. The data obtained in this study regarding the phylogenetic relationships and the community structure of intestinal bacteria at different developmental stages of the D. armandi life cycle contribute to our understanding of D. armandi and could aid the development of new pest control strategies.

  19. Study on the biological characteristic of Dendroctonus valensle%强大小蠹生物学特性研究

    Institute of Scientific and Technical Information of China (English)

    苗振旺; 周维民; 霍履远; 王晓丽; 范俊秀; 赵明梅

    2001-01-01

    强大小蠹(Dendroctonus valens LeConte)是近年来发现为害油松的国内新纪录种,1998年在山西省阳城、沁水等县首次发现,此后在全省各地暴发成灾.该虫在榆次市、太岳山林区一年发生一代,主要以老熟幼虫和成虫在树干基部或根部的皮层内越冬,也有少数以2龄~3龄幼虫或蛹越冬.越冬成虫于5月中下旬大量出孔扬飞,6月上旬为产卵盛期,6月中旬为孵化盛期,8月中旬为化蛹盛期,9月上旬为子代成虫羽化盛期.越冬老熟幼虫于7月中旬大量化蛹,7月下旬为羽化盛期,8月上中旬为产卵盛期,8月中旬为卵孵化盛期,发育不整齐,有世代重叠现象.

  20. 红脂大小蠹发生规律研究%Occurrence Regularity of Dendroctonus valens

    Institute of Scientific and Technical Information of China (English)

    常宝山; 刘随存; 赵小梅; 孙永明; 马峰; 徐庭祥

    2001-01-01

    红脂大小蠹(Dendroctonus valens)1998年7月在山西省阳城县阳陵林场首次发现,为害并可致死健康油松、华山松,是国内新纪录种.该虫在晋城地区一年发生2代,以成虫、蛹、幼虫在树干基部和主、侧根皮层的取食坑道内越冬.成虫3月中旬开始活动,4月下旬开始侵入寄主,5月上中旬为越冬代成虫扬飞、侵入和产卵盛期,8月中下旬为第一代成虫扬飞、侵入和产卵盛期,10月下旬第二代成虫开始羽化.在温度、湿度和寄主等因子的共同影响下,其发育不太整齐,有世代重叠现象.

  1. Climate Drives Episodic Conifer Establishment after Fire in Dry Ponderosa Pine Forests of the Colorado Front Range, USA

    Directory of Open Access Journals (Sweden)

    Monica T. Rother

    2017-05-01

    Full Text Available In recent years, warming climate and increased fire activity have raised concern about post-fire recovery of western U.S. forests. We assessed relationships between climate variability and tree establishment after fire in dry ponderosa pine forests of the Colorado Front Range. We harvested and aged over 400 post-fire juvenile ponderosa pine (Pinus ponderosa and Douglas-fir (Pseudotsuga menziesii trees using an improved tree-ring based approach that yielded annually-resolved dates and then assessed relationships between climate variability and pulses of tree establishment. We found that tree establishment was largely concentrated in years of above-average moisture availability in the growing season, including higher amounts of precipitation and more positive values of the Palmer Drought Severity Index. Under continued climate change, drier conditions associated with warming temperatures may limit forest recovery after fire, which could result in lower stand densities or shifts to non-forested vegetation in some areas.

  2. Nitrogen spatial heterogeneity influences diversity following restoration in a ponderosa pine forest, Montana.

    Science.gov (United States)

    Gundale, Michael J; Metlen, Kerry L; Fiedler, Carl E; DeLuca, Thomas H

    2006-04-01

    The resource heterogeneity hypothesis (RHH) is frequently cited in the ecological literature as an important mechanism for maintaining species diversity. The RHH has rarely been evaluated in the context of restoration ecology in which a commonly cited goal is to restore diversity. In this study we focused on the spatial heterogeneity of total inorganic nitrogen (TIN) following restoration treatments in a ponderosa pine (Pinus ponderosa)/Douglas-fir (Pseudotsuga menziesii) forest in western Montana, USA. Our objective was to evaluate relationships between understory species richness and TIN heterogeneity following mechanical thinning (thin-only), prescribed burning (burn-only), and mechanical thinning with prescribed burning (thin/burn) to discern the ecological and management implications of these restoration approaches. We employed a randomized block design, with three 9-ha replicates of each treatment and an untreated control. Within each treatment, we randomly established a 20 x 50 m (1000 m2) plot in which we measured species richness across the entire plot and in 12 1-m(2) quadrats randomly placed within each larger plot. Additionally, we measured TIN from a grid consisting of 112 soil samples (0-5 cm) in each plot and computed standard deviations as a measure of heterogeneity. We found a correlation between the net increase in species richness and the TIN standard deviations one and two years following restoration treatments, supporting RHH. Using nonmetric multidimensional scaling ordination and chi-squared analysis, we found that high and low TIN quadrats contained different understory communities in 2003 and 2004, further supporting RHH. A comparison of restoration treatments demonstrated that thin/burn and burn-only treatments created higher N heterogeneity relative to the control. We also found that within prescribed burn treatments, TIN heterogeneity was positively correlated with fine-fuel consumption, a variable reflecting burn severity. These

  3. Soil compaction effects on water status of ponderosa pine assessed through 13C/12C composition.

    Science.gov (United States)

    Gomez, G Armando; Singer, Michael J; Powers, Robert F; Horwath, William R

    2002-05-01

    Soil compaction is a side effect of forest reestablishment practices resulting from use of heavy equipment and site preparation. Soil compaction often alters soil properties resulting in changes in plant-available water. The use of pressure chamber methods to assess plant water stress has two drawbacks: (1) the measurements are not integrative; and (2) the method is difficult to apply extensively to establish seasonal soil water status. We evaluated leaf carbon isotopic composition (delta13C) as a means of assessing effects of soil compaction on water status and growth of young ponderosa pine (Pinus ponderosa var. ponderosa Dougl. ex Laws) stands across a range of soil textures. Leaf delta13C in cellulose and whole foliar tissue were highly correlated. Leaf delta13C in both whole tissue and cellulose (holocellulose) was up to 1.0 per thousand lower in trees growing in non-compacted (NC) loam or clay soils than in compacted (SC) loam or clay soils. Soil compaction had the opposite effect on leaf delta13C in trees growing on sandy loam soil, indicating that compaction increased water availability in this soil type. Tree growth response to compaction also varied with soil texture, with no effect, a negative effect and a positive effect as a result of compaction of loam, clay and sandy loam soils, respectively. There was a significant correlation between 13C signature and tree growth along the range of soil textures. Leaf delta13C trends were correlated with midday stem water potentials. We conclude that leaf delta13C can be used to measure retrospective water status and to assess the impact of site preparation on tree growth. The advantage of the leaf delta13C approach is that it provides an integrative assessment of past water status in different aged leaves.

  4. Partitioning of water flux in a Sierra Nevada ponderosa pine plantation

    Science.gov (United States)

    Kurpius, M.R.; Panek, J.A.; Nikolov, N.T.; McKay, M.; Goldstein, Allen H.

    2003-01-01

    The weather patterns of the west side of the Sierra Nevada Mountains (cold, wet winters and hot, dry summers) strongly influence how water is partitioned between transpiration and evaporation and result in a specific strategy of water use by ponderosa pine trees (Pinus ponderosa) in this region. To investigate how year-round water fluxes were partitioned in a young ponderosa pine ecosystem in the Sierra Nevada Mountains, water fluxes were continually measured from June 2000 to May 2001 using a combination of sap flow and eddy covariance techniques (above- and below-canopy). Water fluxes were modeled at our study site using a biophysical model, FORFLUX. During summer and fall water fluxes were equally partitioned between transpiration and soil evaporation while transpiration dominated the water fluxes in winter and spring. The trees had high rates of canopy conductance and transpiration in the early morning and mid-late afternoon and a mid-day depression during the dry season. We used a diurnal centroid analysis to show that the timing of high canopy conductance and transpiration relative to high vapor pressure deficit (D) shifted with soil moisture: during periods of low soil moisture canopy conductance and transpiration peaked early in the day when D was low. Conversely, during periods of high soil moisture canopy conductance and transpiration peaked at the same time or later in the day than D. Our observations suggest a general strategy by the pine trees in which they maximize stomatal conductance, and therefore carbon fixation, throughout the day on warm sunny days with high soil moisture (i.e. warm periods in winter and late spring) and maximize stomatal conductance and carbon fixation in the morning through the dry periods. FORFLUX model estimates of evaporation and transpiration were close to measured/calculated values during the dry period, including the drought, but underestimated transpiration and overestimated evaporation during the wet period. ?? 2003

  5. Climate effects on fire regimes and tree recruitment in Black Hills ponderosa pine forests.

    Science.gov (United States)

    Brown, Peter M

    2006-10-01

    Climate influences forest structure through effects on both species demography (recruitment and mortality) and disturbance regimes. Here, I compare multi-century chronologies of regional fire years and tree recruitment from ponderosa pine forests in the Black Hills of southwestern South Dakota and northeastern Wyoming to reconstructions of precipitation and global circulation indices. Regional fire years were affected by droughts and variations in both Pacific and Atlantic sea surface temperatures. Fires were synchronous with La Niñas, cool phases of the Pacific Decadal Oscillation (PDO), and warm phases of the Atlantic Multidecadal Oscillation (AMO). These quasi-periodic circulation features are associated with drought conditions over much of the western United States. The opposite pattern (El Niño, warm PDO, cool AMO) was associated with fewer fires than expected. Regional tree recruitment largely occurred during wet periods in precipitation reconstructions, with the most abundant recruitment coeval with an extended pluvial from the late 1700s to early 1800s. Widespread even-aged cohorts likely were not the result of large crown fires causing overstory mortality, but rather were caused by optimal climate conditions that contributed to synchronous regional recruitment and longer intervals between surface fires. Synchronous recruitment driven by climate is an example of the Moran effect. The presence of abundant fire-scarred trees in multi-aged stands supports a prevailing historical model for ponderosa pine forests in which recurrent surface fires affected heterogenous forest structure, although the Black Hills apparently had a greater range of fire behavior and resulting forest structure over multi-decadal time scales than ponderosa pine forests of the Southwest that burned more often.

  6. Stand-replacing wildfires increase nitrification for decades in southwestern ponderosa pine forests.

    Science.gov (United States)

    Kurth, Valerie J; Hart, Stephen C; Ross, Christopher S; Kaye, Jason P; Fulé, Peter Z

    2014-05-01

    Stand-replacing wildfires are a novel disturbance within ponderosa pine (Pinus ponderosa) forests of the southwestern United States, and they can convert forests to grasslands or shrublands for decades. While most research shows that soil inorganic N pools and fluxes return to pre-fire levels within a few years, we wondered if vegetation conversion (ponderosa pine to bunchgrass) following stand-replacing fires might be accompanied by a long-term shift in N cycling processes. Using a 34-year stand-replacing wildfire chronosequence with paired, adjacent unburned patches, we examined the long-term dynamics of net and gross nitrogen (N) transformations. We hypothesized that N availability in burned patches would become more similar to those in unburned patches over time after fire as these areas become re-vegetated. Burned patches had higher net and gross nitrification rates than unburned patches (P < 0.01 for both), and nitrification accounted for a greater proportion of N mineralization in burned patches for both net (P < 0.01) and gross (P < 0.04) N transformation measurements. However, trends with time-after-fire were not observed for any other variables. Our findings contrast with previous work, which suggested that high nitrification rates are a short-term response to disturbance. Furthermore, high nitrification rates at our site were not simply correlated with the presence of herbaceous vegetation. Instead, we suggest that stand-replacing wildfire triggers a shift in N cycling that is maintained for at least three decades by various factors, including a shift from a woody to an herbaceous ecosystem and the presence of fire-deposited charcoal.

  7. Frequent fire alters nitrogen transformations in ponderosa pine stands of the inland northwest.

    Science.gov (United States)

    DeLuca, Thomas H; Sala, Anna

    2006-10-01

    Recurrent, low-severity fire in ponderosa pine (Pinus ponderosa)/interior Douglas-fir (Pseudotsuga menziesii var. glauca) forests is thought to have directly influenced nitrogen (N) cycling and availability. However, no studies to date have investigated the influence of natural fire intervals on soil processes in undisturbed forests, thereby limiting our ability to understand ecological processes and successional dynamics in this important ecosystem of the Rocky Mountain West. Here, we tested the standing hypothesis that recurrent fire in ponderosa pine/Douglas-fir forests of the Inland Northwest decreases total soil N, but increases N turnover and nutrient availability. We compared soils in stands unburned over the past 69-130 years vs. stands exposed to two or more fires over the last 130 years at seven distinct locations in two wilderness areas. Mineral soil samples were collected from each of the seven sites in June and July of 2003 and analyzed for pH, total C and N, potentially mineralizable N (PMN), and extractable NH4+, NO3-, PO4(-3), Ca+2, Mg+2, and K+. Nitrogen transformations were assessed at five sites by installing ionic resin capsules in the mineral soil in August of 2003 and by conducting laboratory assays of nitrification potential and net nitrification in aerobic incubations. Total N and PMN decreased in stands subjected to multiple fires. This loss of total N and labile N was not reflected in concentrations of extractable NH4+ and NO3-. Rather, multiple fires caused an increase in NO3 sorbed on ionic resins, nitrification potential, and net nitrification in spite of the burned stands not having been exposed to fire for at least 12-17 years. Charcoal collected from a recent fire site and added to unburned soils increased nitrification potential, suggesting that the decrease of charcoal in the absence of fire may play an important role in N transformations in fire-dependent ecosystems in the long term. Interestingly, we found no consistent effect of

  8. Vegetation management for reducing mortality of ponderosa pine seedlings from Thomomys spp

    Science.gov (United States)

    Barnes, V.G.; Anthony, M.; ,

    1995-01-01

    The effects of vegetation management on Mazama pocket gopher activity and damage to ponderosa pine seedlings were studied using atrazine herbicide to alter the habitat. Atrazine treatments were applied to a large treatment unit and observed effects were compared to an untreated control unit. The greatly reduced forb and grass cover on the treated unit was associated with a corresponding decrease in pocket gopher activity. Times until seedlings first incurred gopher damage and overall survival of two cohorts of seedlings were greatly increased on the treated unit.

  9. 我国红脂大小蠹生物学与防治研究概况%Progresses on Dendroctonus valens

    Institute of Scientific and Technical Information of China (English)

    张强; 陈安良; 郝双红; 张兴

    2004-01-01

    红脂大小蠹(Dendroctonus valens)是近年严重危害我国北方油松林的森林害虫.本文总结了5 a来我国红脂大小蠹的生物学和防治方法研究进展,建议在防治红脂大小蠹时,应加强检疫工作,防止扩散,加强天敌利用工作,大力发展信息素防治法,同时积极研究新的化学防治方法.

  10. 落叶松大小蠹在中国适生性分析%Analysis of suitability for Dendroctonus simplex Leconte in China

    Institute of Scientific and Technical Information of China (English)

    王齐; 王志明; 郭建波; 魏春艳; 洪泽源

    2010-01-01

    运用CLIMEX软件和ArcGIS软件,对落叶松大小蠹Dendroctonus simplex Leconte在中国的适生区进行了预测.结果表明:落叶松大小蠹在我国有很高的适生性,适生范围涉及30个省、市、区,其中黑龙江、吉林、内蒙古、新疆东部、西藏中部和青海为高度适生区.

  11. Yeast diversity associated with invasive Dendroctonus valens killing Pinus tabuliformis in China using culturing and molecular methods.

    Science.gov (United States)

    Lou, Qiao-Zhe; Lu, Min; Sun, Jiang-Hua

    2014-08-01

    Bark beetle-associated yeasts are much less studied than filamentous fungi, yet they are also considered to play important roles in beetle nutrition, detoxification, and chemical communication. The red turpentine beetle, Dendroctonus valens, an invasive bark beetle introduced from North America, became one of the most destructive pests in China, having killed more than 10 million Pinus tabuliformis as well as other pine species. No investigation of yeasts associated with this bark beetle in its invaded ranges has been conducted so far. The aim of this study was to assess the diversity of yeast communities in different microhabitats and during different developmental stages of Den. valens in China using culturing and denaturing gradient gel electrophoresis (DGGE) approaches and to compare the yeast flora between China and the USA. The yeast identity was confirmed by sequencing the D1/D2 domain of LSU ribosomal DNA (rDNA). In total, 21 species (13 ascomycetes and eight basidiomycetes) were detected by culturing method, and 12 species (11 ascomycetes and one basidiomycetes) were detected by molecular methods from China. The most frequent five species in China were Candida piceae (Ogataea clade), Cyberlindnera americana, Candida oregonensis (Metschnikowia clade), Candida nitratophila (Ogataea clade) and an undescribed Saccharomycopsis sp., detected by both methods. Seven species were exclusively detected by DGGE. Ca. oregonensis (Metschnikowia clade) was the most frequently detected species by DGGE method. Eight species (all were ascomycetes) from the USA were isolated; seven of those were also found in China. We found significant differences in yeast total abundance as well as community composition between different developmental stages and significant differences between the surface and the gut. The frass yeast community was more similar to that of Den. valens surface or larvae than to the community of the gut or adults. Possible functions of the yeast associates are

  12. Seasonal Phenology and Life-History of Dendroctonus simplex (Coleoptera: Curculionidae) in the Great Lakes Region of North America.

    Science.gov (United States)

    McKee, Fraser R; Aukema, Brian H

    2016-08-01

    The eastern larch beetle, Dendroctonus simplex LeConte (Coleoptera: Curculionidae), is distributed throughout the North American boreal forest sympatric with its primary host, the eastern larch or tamarack, Larix laricina (Du Roi) K. Koch. Outbreaks of eastern larch beetles are typically small and associated with stressed tamaracks. Since 2000, however, an outbreak has killed >90,000 ha of tamarack in Minnesota and surrounding Great Lakes region. Identifying the causes of this epidemic is challenging due to knowledge gaps regarding the insect's biology. We present field data from 2011 to 2014 on degree days associated with spring emergence, dispersal, host colonization, and re-emergence from colonized hosts by mature adult beetles, as well as degree days associated with larval development, and prewinter emergence by adult progeny at study sites in northern Minnesota. After initial host colonization in early spring we found that a second brood was established in early summer by re-emerging parents. In 2012, a third brood was established. Across study years, first broods developed to adults by late summer, with many beetles relocating to the base of the host tree to overwinter. Second broods often reached adulthood and initiated prewinter emergence. The third brood of 2012 overwintered as adults, pupae, and late-instars, resuming development the following spring. Each spring, emergence of adult beetles from all broods established the previous year was highly synchronous. Knowledge of the biology of eastern larch beetles along the southern margin of their range aids in understanding how population dynamics may change with a changing climate.

  13. The great spruce bark beetle (Dendroctonus micans Kug.) (Coleoptera: Scolytidae) in Lithuania: occurrence, phenology, morphology and communities of associated fungi.

    Science.gov (United States)

    Menkis, A; Lynikienė, J; Marčiulynas, A; Gedminas, A; Povilaitienė, A

    2016-11-22

    We studied the occurrence, morphology and phenology of Dendroctonus micans in Lithuania and the fungi associated with the beetle at different developmental stages. The occurrence of D. micans was assessed in 19 seed orchards (at least 40 years old) of Picea abies (L. Karst.) situated in different parts of the country. Bark beetle phenology was studied in two sites: a seed orchard of P. abies and a plantation of Picea pungens (Engelm.). D. micans morphology was assessed under the dissection microscope using individuals at different developmental stages that were sampled during phenology observations. Communities of fungi associated with D. micans were studied using both fungal culturing methods and direct high-throughput sequencing from D. micans. Results showed that the incidence D. micans was relatively rare and D. micans was mainly detected in central and eastern Lithuania. The life cycle included the following stages: adult, egg, I-V developmental stage larvae and pupa. However, development of D. micans was quicker and its nests larger under the bark of P. pungens than of P. abies, indicating the effect of the host species. Fungal culturing and direct high-throughput sequencing revealed that D. micans associated fungi communities were species rich and dominated by yeasts from a class Saccharomycetes. In total, 319 fungal taxa were sequenced, among which Peterozyma toletana (37.5% of all fungal sequences), Yamadazyma scolyti (30.0%) and Kuraishia capsulate (17.7%) were the most common. Plant pathogens and blue stain fungi were also detected suggesting their potentially negative effects to both tree health and timber quality.

  14. Electrophysiological and behavioral responses of the bark beetle Dendroctonus rhizophagus to volatiles from host pines and conspecifics.

    Science.gov (United States)

    Cano-Ramírez, Claudia; Armendáriz-Toledano, Francisco; Macías-Sámano, Jorge E; Sullivan, Brian T; Zúñiga, Gerardo

    2012-05-01

    The bark beetle Dendroctonus rhizophagus is endemic to northwestern Mexico where it kills immature pines < 3 m tall. We report the first investigation of the chemical ecology of this pest of forest regeneration. We used GC-EAD to assess olfactory sensitivity of this species to volatile compounds from: resin of a major host, Pinus arizonica; mid/hindguts of single, gallery-initiating females; and mate-paired males within galleries of attacked host trees in the field. Antennae of both sexes responded to monoterpenes α-pinene, β-pinene and 3-carene as well as to the beetle-derived oxygenated monoterpenes fenchyl alcohol, myrtenal, cis-verbenol, trans-verbenol, verbenone, and myrtenol. These monoterpenes were quantified from pre-emerged D. rhizophagus adults forced to attack host tissue in the laboratory, and from individuals dissected from naturally-attacked hosts at different stages of colonization. In both bioassays, myrtenol and trans-verbenol were the most abundant volatiles, and trans-verbenol was the only one produced in significantly greater quantities by females than males in a naturally-colonized host. Two field experiments were performed to evaluate behavioral responses of D. rhizophagus to antennally-active monoterpenes. Results show that 3-carene was significantly attractive either alone or in a ternary (1:1:1) combination with α-pinene and β-pinene, whereas neither α-pinene nor β-pinene alone were attractive. None of the beetle-associated oxygenated monoterpenes enhanced the attractiveness of the ternary mixture of monoterpenes, while verbenone either alone or combined with the other five oxygenated terpenes reduced D. rhizophagus attraction to the ternary mixture. The results suggest that attraction of D. rhizophagus to the host tree P. arizonica is mediated especially by 3-carene. There was no conclusive evidence for an aggregation or sex attractant pheromone.

  15. Diversity and expression of P450 genes from Dendroctonus valens LeConte (Curculionidae: Scolytinae) in response to different kairomones.

    Science.gov (United States)

    López, María Fernanda; Cano-Ramírez, Claudia; Cesar-Ayala, Ana K; Ruiz, Enrico A; Zúñiga, Gerardo

    2013-05-01

    Bark beetles (Curculionidae: Scolytinae) are major cause of woody plants death in the world. They colonize the stem and other parts of trees recognizing host-produced specific compounds (kairomones) and insect pheromones. Bark beetle's antennae and alimentary canal participate in the host selection identifying chemical compounds produced by trees and insects, and also in the metabolism and detoxification of these compounds. The red turpentine beetle (RTB), Dendroctonus valens LeConte, is an unaggressive species that colonize > 40 pine species (Pinaceae) in North and Central America. Several studies suggest that bark beetle cytochrome P450 enzymes are involved in monoterpene oxidation. In this study we identified by means of PCR, cloning, sequencing, and bioinformatic analysis, eleven full-length genes: five CYP4, four CYP6, and two CYP9 in the antennae and gut region of RTB, after stimulation with vapors of monoterpenes: (±)-α-pinene, (R)-(+)-α-pinene, (S)-(-)-β-pinene, (S)-(-)-α-pinene and (+)-3-carene; pine trees volatiles used by RTB as kairomones. The recovered cDNA of these genes vary from 1.5 kb to 1.8 kb and the open frame encodes from 496 to 562 amino acid proteins. The bioinformatic analysis suggests that the majority of P450 proteins encoded by these genes are membrane anchored in the endoplasmic reticulum. RT-qPCR assays showed differential expression of all CYP genes between male and female. The gene expression was dependent of monoterpenes and exposure time, with some of them sex, antennae and gut region specific. Significant differences among monoterpenes, gut region, antennae and exposure time were found. Our results suggest that some of these genes may be involved in the detoxification process of these compounds during tree colonization. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Evaluating High Release Rate MCH (3-Methylcyclohex-2-en-1-one) Treatments for Reducing Dendroctonus pseudotsugae (Coleoptera: Curculionidae) Infestations.

    Science.gov (United States)

    Brookes, Harrison M; Ross, Darrell W; Strand, Tara M; Thistle, Harold W; Ragenovich, Iral R; Lowrey, Laura L

    2016-12-01

    Current recommendations for applying the antiaggregation pheromone 3-methylcyclohex-2-en-1-one (MCH) to protect live trees from Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, infestation are to space individual passive releasers (MCH bubble capsules) on a 12- by 12-m grid throughout areas to be protected. Previous field studies and a theoretical study using a puff dispersion model to predict pheromone concentrations have shown that releasers emitting higher rates of MCH spaced farther apart may be as effective as the established standard treatment. During 2012 and 2013, we tested higher release rates of MCH at correspondingly wider spacings to keep the total amount of MCH released per unit area equal in all treatments. In 2012 near Challis, ID, treatments included the established standard release rate and spacing, four and six times the standard release rate at correspondingly wider spacings, and an untreated control. In 2013 near Ketchum, ID, treatments included the established standard release rate and spacing, five and seven times the standard release rate at correspondingly wider spacings, and an untreated control. Results from both years indicated that all MCH treatments were equally effective in reducing Douglas-fir beetle infestation. Using higher release rate formulations at wider spacings will reduce labor costs of installing MCH treatments, and, in cases where it is necessary, retrieving the releasers as well. In addition to reducing labor costs, the revised treatment protocol may increase the feasibility of treating areas that currently may not be possible due to treatment costs. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Flying the nest: male dispersal and multiple paternity enables extrafamilial matings for the invasive bark beetle Dendroctonus micans.

    Science.gov (United States)

    Fraser, C I; Brahy, O; Mardulyn, P; Dohet, L; Mayer, F; Grégoire, J-C

    2014-10-01

    There is an evolutionary trade-off between the resources that a species invests in dispersal versus those invested in reproduction. For many insects, reproductive success in patchily-distributed species can be improved by sibling-mating. In many cases, such strategies correspond to sexual dimorphism, with males-whose reproductive activities can take place without dispersal-investing less energy in development of dispersive resources such as large body size and wings. This dimorphism is particularly likely when males have little or no chance of mating outside their place of birth, such as when sperm competition precludes successful fertilisation in females that have already mated. The economically important bark beetle pest species Dendroctonus micans (Coleoptera: Curculionidae, Scolytinae) has been considered to be exclusively sibling-mating, with 90% of females having already mated with their brothers by emergence. The species does not, however, show strong sexual dimorphism; males closely resemble females, and have been observed flying through forests. We hypothesised that this lack of sexual dimorphism indicates that male D. micans are able to mate with unrelated females, and to sire some or all of their offspring, permitting extrafamilial reproduction. Using novel microsatellite markers, we carried out cross-breeding laboratory experiments and conducted paternity analyses of resulting offspring. Our results demonstrate that a second mating with a less-related male can indeed lead to some offspring being sired by the latecomer, but that most are sired by the first, sibling male. We discuss these findings in the context of sperm competition versus possible outbreeding depression.

  18. Radial growth rate increases in naturally occurring ponderosa pine trees: a late-20th century CO2 fertilization effect?

    Science.gov (United States)

    Soulé, Peter T; Knapp, Paul A

    2006-01-01

    The primary objective of this study was to determine if gradually increasing levels of atmospheric CO2, as opposed to 'step' increases commonly employed in controlled studies, have a positive impact on radial growth rates of ponderosa pine (Pinus ponderosa) in natural environments, and to determine the spatial extent and variability of this growth enhancement. We developed a series of tree-ring chronologies from minimally disturbed sites across a spectrum of environmental conditions. A series of difference of means tests were used to compare radial growth post-1950, when the impacts of rising atmospheric CO2 are best expressed, with that pre-1950. Spearman's correlation was used to relate site stress to growth-rate changes. Significant increases in radial growth rates occurred post-1950, especially during drought years, with the greatest increases generally found at the most water-limited sites. Site harshness is positively related to enhanced radial growth rates. Atmospheric CO2 fertilization is probably operative, having a positive effect on radial growth rates of ponderosa pine through increasing water-use efficiency. A CO2-driven growth enhancement may affect ponderosa pine growing under both natural and controlled conditions.

  19. Defoliation of interior Douglas-fir elicits carbon transfer and stress signalling to ponderosa pine neighbors through ectomycorrhizal networks.

    Science.gov (United States)

    Song, Yuan Yuan; Simard, Suzanne W; Carroll, Allan; Mohn, William W; Zeng, Ren Sen

    2015-02-16

    Extensive regions of interior Douglas-fir (Pseudotsuga menziesii var. glauca, IDF) forests in North America are being damaged by drought and western spruce budworm (Choristoneura occidentalis). This damage is resulting from warmer and drier summers associated with climate change. To test whether defoliated IDF can directly transfer resources to ponderosa pine (Pinus ponderosae) regenerating nearby, thus aiding in forest recovery, we examined photosynthetic carbon transfer and defense enzyme response. We grew pairs of ectomycorrhizal IDF 'donor' and ponderosa pine 'receiver' seedlings in pots and isolated transfer pathways by comparing 35 μm, 0.5 μm and no mesh treatments; we then stressed IDF donors either through manual defoliation or infestation by the budworm. We found that manual defoliation of IDF donors led to transfer of photosynthetic carbon to neighboring receivers through mycorrhizal networks, but not through soil or root pathways. Both manual and insect defoliation of donors led to increased activity of peroxidase, polyphenol oxidase and superoxide dismutase in the ponderosa pine receivers, via a mechanism primarily dependent on the mycorrhizal network. These findings indicate that IDF can transfer resources and stress signals to interspecific neighbors, suggesting ectomycorrhizal networks can serve as agents of interspecific communication facilitating recovery and succession of forests after disturbance.

  20. Long-term benefits to the growth of ponderosa pines from controlling southwestern pine tip moth (Lepidoptera: Tortricidae) and weeds.

    Science.gov (United States)

    Wagner, Michael R; Chen, Zhong

    2004-12-01

    The southwestern pine tip moth, Rhyacionia neomexicana (Dyar) (Lepidoptera: Tortricidae), is a native forest pest that attacks seedlings and saplings of ponderosa pine, Pinus ponderosa Dougl. ex Laws, in the southwestern United States. Repeated attacks can cause severe deformation of host trees and significant long-term growth loss. Alternatively, effective control of R. neomexicana, vegetative competition, or both in young pine plantations may increase survival and growth of trees for many years after treatments are applied. We test the null hypothesis that 4 yr of R. neomexicana and weed control with insecticide, weeding, and insecticide plus weeding would not have any residual effect on survival and growth of trees in ponderosa pine plantation in northern Arizona 14 yr post-treatment, when the trees were 18 yr old. Both insecticide and weeding treatment increased tree growth and reduced the incidence of southwestern pine tip moth damage compared with the control. However, weeding alone also significantly increased tree survival, whereas insecticide alone did not. The insecticide plus weeding treatment had the greatest tree growth and survival, and the lowest rate of tip moth damage. Based on these results, we rejected our null hypothesis and concluded that there were detectable increases in the survival and growth of ponderosa pines 14 yr after treatments applied to control R. neomexicana and weeds.

  1. CO2 AND N-FERTILIZATION EFFECTS ON FINE ROOT LENGTH, PRODUCTION, AND MORTALITY: A 4-YEAR PONDEROSA PINE STUDY

    Science.gov (United States)

    We conducted a 4-year study of Pinus ponderosa fine root (<2 mm) responses to atmospheric CO2 and N-fertilization. Seedlings were grown in open-top chambers at 3 CO2 levels (ambient, ambient+175 mol/mol, ambient+350 mol/mol) and 3 N-fertilization levels (0, 10, 20 g?m-2?yr-1). ...

  2. Simulating historical disturbance regimes and stand structures in old-forest ponderosa pine/Douglas-fir forests

    Science.gov (United States)

    Mike Hillis; Vick Applegate; Steve Slaughter; Michael G. Harrington; Helen Smith

    2001-01-01

    Forest Service land managers, with the collaborative assistance from research, applied a disturbance based restoration strategy to rehabilitate a greatly-altered, high risk Northern Rocky Mountain old-forest ponderosa pine-Douglas-fir stand. Age-class structure and fire history for the site have been documented in two research papers (Arno and others 1995, 1997)....

  3. Abundance and characteristics of lignin liquid intermediates in wood (Pinus ponderosa Dougl. ex Laws.) during hot water extraction

    Science.gov (United States)

    Manuel Raul Pelaez-Samaniego; Vikram Yadama; Manuel Garcia-Perez; Eini Lowell

    2015-01-01

    The objective of this research was to investigate the effects of the conditions of hot water extraction (HWE) on abundance, properties, and structure of lignin depolymerization products. HWE of extracted softwood (ponderosa pine) was conducted using temperatures from 140 to 320°C for 90 min. HWE materials were then subjected to a soxhlet...

  4. Long-term effects of fuel treatments on aboveground biomass accumulation in ponderosa pine forests of the northern Rocky Mountains

    Science.gov (United States)

    Kate A. Clyatt; Christopher R. Keyes; Sharon M. Hood

    2017-01-01

    Fuel treatments in ponderosa pine forests of the northern Rocky Mountains are commonly used to modify fire behavior, but it is unclear how different fuel treatments impact the subsequent production and distribution of aboveground biomass, especially in the long term. This research evaluated aboveground biomass responses 23 years after treatment in two silvicultural...

  5. Effect of dietary protein level and quebracho tannin on consumption of pine needles (Pinus ponderosa) by beef cows

    Science.gov (United States)

    Ponderosa pine trees occupy over 15 million hectares of rangeland in western North America. Pregnant cows often consume pine needles (PN), and subsequently abort. The protein-to-energy ratio may be important in the ability of cattle to tolerate dietary terpenes. Tannins often co-occur with terpenes ...

  6. Making a stand: five centuries of population growth in colonizing populations of Pinus ponderosa.

    Science.gov (United States)

    Lesser, Mark R; Jackson, Stephen T

    2012-05-01

    The processes underlying the development of new populations are important for understanding how species colonize new territory and form viable long-term populations. Life-history-mediated processes such as Allee effects and dispersal capability may interact with climate variability and site-specific factors to govern population success and failure over extended time frames. We studied four disjunct populations of ponderosa pine in the Bighorn Basin of north-central Wyoming to examine population growth spanning more than five centuries. The study populations are separated from continuous ponderosa pine forest by distances ranging from 15 to >100 km. Strong evidence indicates that the initial colonizing individuals are still present, yielding a nearly complete record of population history. All trees in each population were aged using dendroecological techniques. The populations were all founded between 1530 and 1655 cal yr CE. All show logistic growth patterns, with initial exponential growth followed by a slowing during the mid to late 20th century. Initial population growth was slower than expectations from a logistic regression model at all four populations, but increased during the mid-18th century. Initial lags in population growth may have been due to strong Allee effects. A combination of overcoming Allee effects and a transition to favorable climate conditions may have facilitated a mid-18th century pulse in population growth rate.

  7. Comparison of ponderosa pines as feed and nonfeed trees for abert squirrels.

    Science.gov (United States)

    Pederson, J C; Welch, B L

    1985-02-01

    Twigs from five ponderosa pine trees (Pinus ponderosa) used by Abert squirrels (Sciurus aberti) as feed trees and five nonfeed trees were collected every 45 days and their monoterpenoid and nutrient content determined. Thet tests (unpaired observations) detected no significant difference in the level of monoterpenoids in the outer bark of feed (0.77%) and nonfeed (0.75%) trees. The same was true for inner bark of feed (0.10%) and nonfeed (0.16%) trees. Monoterpenoid levels in outer bark (0.75%) were significantly higher than inner bark (0.13%). The inner bark is what is eaten by Abert squirrels. Protein and other nutrients did not differ significantly between feed and nonfeed trees. However, both outer and inner bark were easier to remove from the woody portion of the feed tree twigs than those twigs collected from nonfeed trees. Therefore, due to the lack of differences in monoterpenoid and nutrient content between feed and nonfeed trees, we attributed the use of certain trees for use as feed trees to the ease of peeling and separating outer from inner bark.

  8. Height-related growth declines in ponderosa pine are not due to carbon limitation.

    Science.gov (United States)

    Sala, Anna; Hoch, Günter

    2009-01-01

    Decreased gas exchange as trees grow tall has been proposed to explain age-related growth declines in trees. We examined changes of mobile carbon stores (starch, sugars and lipids) with tree height in ponderosa pine (Pinus ponderosa) at two sites differing in water availability, and tested the following hypotheses: (1) carbon supply does not become increasingly limited as trees grow tall; rather, the concentration of mobile carbon compounds increases with tree height reflecting greater reductions of carbon sink activities relative to carbon assimilation; and (2) increases of stored mobile carbon compounds with tree height are greater in drier sites. Height-related growth reductions were associated with significant increases of non-structural carbohydrates (NSC) and lipid concentrations in all tissues in the upper canopy and of NSC in the bole. Lipid concentrations in the bole decreased with tree height, but such decrease is not necessarily inconsistent with non-limiting carbon supply in tall trees. Furthermore, we found stronger increases of mobile carbon stores with tree height at the dry site relative to the moist site. Our results provide first direct evidence that carbon supply does not limit growth in tall trees and that decreases of water availability might negatively impact growth processes more than net-photosynthesis.

  9. Maize, switchgrass, and ponderosa pine biochar added to soil increased herbicide sorption and decreased herbicide efficacy.

    Science.gov (United States)

    Clay, Sharon A; Krack, Kaitlynn K; Bruggeman, Stephanie A; Papiernik, Sharon; Schumacher, Thomas E

    2016-08-02

    Biochar, a by-product of pyrolysis made from a wide array of plant biomass when producing biofuels, is a proposed soil amendment to improve soil health. This study measured herbicide sorption and efficacy when soils were treated with low (1% w/w) or high (10% w/w) amounts of biochar manufactured from different feedstocks [maize (Zea mays) stover, switchgrass (Panicum vigatum), and ponderosa pine (Pinus ponderosa)], and treated with different post-processing techniques. Twenty-four hour batch equilibration measured sorption of (14)C-labelled atrazine or 2,4-D to two soil types with and without biochar amendments. Herbicide efficacy was measured with and without biochar using speed of seed germination tests of sensitive species. Biochar amended soils sorbed more herbicide than untreated soils, with major differences due to biochar application rate but minor differences due to biochar type or post-process handling technique. Biochar presence increased the speed of seed germination compared with herbicide alone addition. These data indicate that biochar addition to soil can increase herbicide sorption and reduce efficacy. Evaluation for site-specific biochar applications may be warranted to obtain maximal benefits without compromising other agronomic practices.

  10. Western juniper and ponderosa pine ecotonal climate-growth relationships across landscape gradients in southern Oregon

    Science.gov (United States)

    Knutson, K.C.; Pyke, D.A.

    2008-01-01

    Forecasts of climate change for the Pacific northwestern United States predict warmer temperatures, increased winter precipitation, and drier summers. Prediction of forest growth responses to these climate fluctuations requires identification of climatic variables limiting tree growth, particularly at limits of free species distributions. We addressed this problem at the pine-woodland ecotone using tree-ring data for western juniper (Juniperus occidentalis var. occidentalis Hook.) and ponderosa pine (Pinus ponderosa Dougl. ex Loud.) from southern Oregon. Annual growth chronologies for 1950-2000 were developed for each species at 17 locations. Correlation and linear regression of climate-growth relationships revealed that radial growth in both species is highly dependent on October-June precipitation events that recharge growing season soil water. Mean annual radial growth for the nine driest years suggests that annual growth in both species is more sensitive to drought at lower elevations and sites with steeper slopes and sandy or rocky soils. Future increases in winter precipitation could increase productivity in both species at the pine-woodland ecotone. Growth responses, however, will also likely vary across landscape features, and our findings suggest that heightened sensitivity to future drought periods and increased temperatures in the two species will predominantly occur at lower elevation sites with poor water-holding capacities. ?? 2008 NRC.

  11. Fire-induced erosion and millennial-scale climate change in northern ponderosa pine forests.

    Science.gov (United States)

    Pierce, Jennifer L; Meyer, Grant A; Jull, A J Timothy

    2004-11-04

    Western US ponderosa pine forests have recently suffered extensive stand-replacing fires followed by hillslope erosion and sedimentation. These fires are usually attributed to increased stand density as a result of fire suppression, grazing and other land use, and are often considered uncharacteristic or unprecedented. Tree-ring records from the past 500 years indicate that before Euro-American settlement, frequent, low-severity fires maintained open stands. However, the pre-settlement period between about ad 1500 and ad 1900 was also generally colder than present, raising the possibility that rapid twentieth-century warming promoted recent catastrophic fires. Here we date fire-related sediment deposits in alluvial fans in central Idaho to reconstruct Holocene fire history in xeric ponderosa pine forests and examine links to climate. We find that colder periods experienced frequent low-severity fires, probably fuelled by increased understory growth. Warmer periods experienced severe droughts, stand-replacing fires and large debris-flow events that comprise a large component of long-term erosion and coincide with similar events in sub-alpine forests of Yellowstone National Park. Our results suggest that given the powerful influence of climate, restoration of processes typical of pre-settlement times may be difficult in a warmer future that promotes severe fires.

  12. Effects of long-term elevated atmospheric CO{sub 2} concentrations on Pinus ponderosa

    Energy Technology Data Exchange (ETDEWEB)

    Surano, K.A.; Kercher, J.R. [eds.

    1993-10-01

    This report details the results from an experiment of the effects of long-term elevated atmospheric CO{sub 2} concentrations on ponderosa pine (Pinus ponderosa Laws.) saplings and seedlings. The study began in 1983 as a pilot study designed to explore the feasibility of using open-top chambers for continuous multi-year exposures on sapling-sized trees and to examine possible CO{sub 2} responses so that future research could be adequately designed. however, following the first year of exposure, preliminary results from the study indicated that measurements of CO{sub 2} responses should be intensified. Open-top chambers proved suitable for use in multiyear exposures of mature trees. With respect to the preliminary examination of CO{sub 2} responses, many interesting observations were made. The nature of the preliminary results suggests that future long-term field CO{sub 2} exposures on perennial species may be critical to the understanding and preparation for future environments. Other research reported here attempted to adapt an existing western coniferous forest growth and succession model for use in elevated CO{sub 2} scenarios using differential species responses, and assessed the usefulness of the model in that regard. Seven papers have been processed separately for inclusion in the appropriate data bases.

  13. 红脂大小蠹诱捕效果影响因素分析%Influencing Factors of the Effect of Trapping Dendroctonus valens LeConte

    Institute of Scientific and Technical Information of China (English)

    郭保平

    2012-01-01

    The influencing factors of trapping Dendroctonus valens LeConte have been analyzed by use of placing the traps in different positions in Pinus koraiensis pure forest. The results showed that with increase in distance from the forest edge, the trapping effect became worse. For inside forest, outside forest and forest edge, the trapping effect in forest edge was the best. With the inetreasing of canopy density, the trapping quantity decreased. The traps should be placed in forest edge or the place with small canopy density for controlling Dendroctonus valens LeConte by use of traps.%采用在红松纯林不同位置放置诱捕器的方法,分析了影响红脂大小蠹诱捕的因素。结果表明:距林缘距离越大,诱捕效果越差;对于林内、林外和林缘来说,林缘诱捕效果最好;随着郁闭度的增大,诱捕数量减少。因此,在用诱捕器防治红脂大小蠹时,应将诱捕器放置在林缘或者郁闭度较小的地方。

  14. Isozyme markers associated with O(3) tolerance indicate shift in genetic structure of ponderosa and Jeffrey pine in Sequoia National Park, California.

    Science.gov (United States)

    Staszak, J; Grulke, N E; Marrett, M J; Prus-Glowacki, W

    2007-10-01

    Effects of canopy ozone (O(3)) exposure and signatures of genetic structure using isozyme markers associated with O(3) tolerance were analyzed in approximately 20-, approximately 80-, and >200-yr-old ponderosa (Pinus ponderosa Dougl. ex Laws.) and Jeffrey pine (Pinus jeffreyi Grev. & Balf.) in Sequoia National Park, California. For both species, the number of alleles and genotypes per loci was higher in parental trees relative to saplings. In ponderosa pine, the heterozygosity value increased, and the fixation index indicated reduction of homozygosity with increasing tree age class. The opposite tendencies were observed for Jeffrey pine. Utilizing canopy attributes known to be responsive to O(3) exposure, ponderosa pine was more symptomatic than Jeffrey pine, and saplings were more symptomatic than old growth trees. We suggest that these trends are related to differing sensitivity of the two species to O(3) exposure, and to higher O(3) exposures and drought stress that younger trees may have experienced during germination and establishment.

  15. Diesel fuel oil for increasing mountain pine beetle mortality in felled logs

    Science.gov (United States)

    S. A. Mata; J. M. Schmid; D. A. Leatherman

    2002-01-01

    Diesel fuel oil was applied to mountain pine beetle (Dendroctonus ponderosae Hopkins) infested bolts of ponderosa pine (Pinus ponderosa Lawson) in early June. Just prior to the fuel oil application and 6 weeks later, 0.5 ft2 bark samples were removed from each bolt and the numbers of live beetles counted....

  16. Suitability of live and fire-killed small-diameter ponderosa and lodgepole pine trees for manufacturing a new structural wood composite.

    Science.gov (United States)

    Linton, J M; Barnes, H M; Seale, R D; Jones, P D; Lowell, E C; Hummel, S S

    2010-08-01

    Finding alternative uses for raw material from small-diameter trees is a critical problem throughout the United States. In western states, a lack of markets for small-diameter ponderosa pine (Pinus ponderosa) and lodgepole pine (Pinus contorta) can contribute to problems associated with overstocking. To test the feasibility of producing structural composite lumber (SCL) beams from these two western species, we used a new technology called steam-pressed scrim lumber (SPSL) based on scrimming technology developed in Australia. Both standing green and fire-killed ponderosa and lodgepole pine logs were used in an initial test. Fire-killed logs of both species were found to be unsuitable for producing SPSL but green logs were suitable for producing SPSL. For SPSL from green material, ponderosa pine had significantly higher modulus of rupture and work-to-maximum load values than did SPSL from lodgepole pine. Modulus of elasticity was higher for lodgepole pine. The presence of blows was greater with lodgepole pine than with ponderosa. Blows had a negative effect on the mechanical properties of ponderosa pine but no significant effect on the mechanical properties of SPSL from lodgepole pine. An evaluation of non-destructive testing methods showed that X-ray could be used to determine low density areas in parent beams. The use of a sonic compression wave tester for NDE evaluation of modulus of rupture showed some promise with SPSL but requires further research.

  17. Controls on vegetation structure in Southwestern ponderosa pine forests, 1941 and 2004.

    Science.gov (United States)

    Bakker, Jonathan D; Moore, Margaret M

    2007-09-01

    Long-term studies can broaden our ecological understanding and are particularly important when examining contingent effects that involve changes to dominance by long-lived species. Such a change occurred during the last century in Southwestern (USA) ponderosa pine (Pinus ponderosa) forests. We used five livestock grazing exclosures established in 1912 to quantify vegetation structure in 1941 and 2004. Our objectives were to (1) assess the effects of historical livestock grazing on overstory structure and age distribution, (2) assess the effects of recent livestock grazing and overstory on understory vegetation, and (3) quantify and explain changes in understory vegetation between 1941 and 2004. In 1941, canopy cover of tree regeneration was significantly higher inside exclosures. In 2004, total tree canopy cover was twice as high, density was three times higher, trees were smaller, and total basal area was 40% higher inside exclosures. Understory species density, herbaceous plant density, and herbaceous cover were negatively correlated with overstory vegetation in both years. Most understory variables did not differ between grazing treatments in 1941 but were lower inside exclosures in 2004. Differences between grazing treatments disappeared once overstory effects were accounted for, indicating that they were due to the differential overstory response to historical livestock grazing practices. Between 1941 and 2004, species density declined by 34%, herbaceous plant density by 37%, shrub cover by 69%, total herbaceous cover by 59%, graminoid cover by 39%, and forb cover by 82%. However, these variables did not differ between grazing treatments or years once overstory effects were accounted for, indicating that the declines were driven by the increased dominance of the overstory during this period. Our results demonstrate that historical livestock grazing practices are an aspect of land-use history that can affect ecosystem development. Grazing history must be

  18. Quantifying post-fire ponderosa pine snags using GIS techniques on scanned aerial photographs

    Science.gov (United States)

    Kent, Kevin

    Snags are an important component of forest ecosystems because of their utility in forest-nutrient cycling and provision of critical wildlife habitat, as well as associated fuel management concerns relating to coarse woody debris (CWD). Knowledge of snag and CWD trajectories are needed for land managers to plan for long-term ecosystem change in post-fire regimes. This need will likely be exacerbated by increasingly warm and dry climatic conditions projected for the U.S. Southwest. One of the best prospects for studying fire-induced landscape change beyond the plot scale, but still at a resolution sufficient to resolve individual snags, is to utilize the available aerial photography record. Previous field-based studies of snag and CWD loads in the Southwest have relied on regional chronosequences to judge the recovery dynamic of ponderosa pine (Pinus ponderosa) burns. This previous research has been spatially and temporally restricted because of field survey extent limitations and uncertainty associated with the chronosequence approach (i.e., space-for-time substitution), which does not consider differences between specific site conditions and histories. This study develops highly automated methods for remotely quantifying and characterizing the spatial and temporal distribution of large snags associated with severe forest fires from very high resolution (VHR) landscape imagery I obtained from scans of aerial photos. Associated algorithms utilize the sharp edges, shape, shadow, and contrast characteristics of snags to enable feature recognition. Additionally, using snag shadow length, image acquisition time, and location information, heights were estimated for each identified snag. Furthermore, a novel solution was developed for extracting individual snags from areas of high snag density by overlaying parallel lines in the direction of the snag shadows and extracting local maxima lines contained by each snag polygon. Field survey data coincident to imagery coverage

  19. Water limitations to carbon exchange in old-growth and young ponderosa pine stands.

    Science.gov (United States)

    Irvine, J; Law, B E; Anthoni, P M; Meinzer, F C

    2002-02-01

    We investigated the impact of seasonal soil water deficit on the processes driving net ecosystem exchange of carbon (NEE) in old-growth and recently regenerating ponderosa pine (Pinus ponderosa Doug. ex Laws.) stands in Oregon. We measured seasonal patterns of transpiration, canopy conductance and NEE, as well as soil water, soil temperature and soil respiration. The old-growth stand (O) included two primary age classes (50 and 250 years), had a leaf area index (LAI) of 2.1 and had never been logged. The recently regenerating stand (Y) consisted predominantly of 14-year-old ponderosa pine with an LAI of 1.0. Both stands experienced similar meteorological conditions with moderately cold wet winters and hot dry summers. By August, soil volumetric water content within the upper 30 cm had declined to a seasonal minimum of 0.07 at both sites. Between April and June, both stands showed similar rates of transpiration peaking at 0.96 mm day(-1); thereafter, trees at the Y site showed increasing drought stress with canopy stomatal resistance increasing 6-fold by mid-August relative to values for trees at the O site. Over the same period, predawn water potential (psi(pd)) of trees at the Y site declined from -0.54 to -1.24 MPa, whereas psi(pd) of trees at the O site remained greater than -0.8 MPa throughout the season. Soil respiration at the O site showed a strong seasonal correlation with soil temperature with no discernible constraints imposed by declining soil water. In contrast, soil respiration at the Y site peaked before seasonal maximal soil temperatures and declined thereafter with declining soil water. No pronounced seasonal pattern in daytime NEE was observed at either site between April and September. At the Y site this behavior was driven by concurrent soil water limitations on soil respiration and assimilation, whereas there was no evidence of seasonal soil water limitations on either process at the O site.

  20. Native root xylem embolism and stomatal closure in stands of Douglas-fir and ponderosa pine: mitigation by hydraulic redistribution.

    Science.gov (United States)

    Domec, J-C; Warren, J M; Meinzer, F C; Brooks, J R; Coulombe, R

    2004-09-01

    Hydraulic redistribution (HR), the passive movement of water via roots from moist to drier portions of the soil, occurs in many ecosystems, influencing both plant and ecosystem-water use. We examined the effects of HR on root hydraulic functioning during drought in young and old-growth Douglas-fir [ Pseudotsuga menziesii (Mirb.) Franco] and ponderosa pine ( Pinus ponderosa Dougl. Ex Laws) trees growing in four sites. During the 2002 growing season, in situ xylem embolism, water deficit and xylem vulnerability to embolism were measured on medium roots (2-4-mm diameter) collected at 20-30 cm depth. Soil water content and water potentials were monitored concurrently to determine the extent of HR. Additionally, the water potential and stomatal conductance ( g(s)) of upper canopy leaves were measured throughout the growing season. In the site with young Douglas-fir trees, root embolism increased from 20 to 55 percent loss of conductivity (PLC) as the dry season progressed. In young ponderosa pine, root embolism increased from 45 to 75 PLC. In contrast, roots of old-growth Douglas-fir and ponderosa pine trees never experienced more than 30 and 40 PLC, respectively. HR kept soil water potential at 20-30 cm depth above -0.5 MPa in the old-growth Douglas-fir site and -1.8 MPa in the old-growth ponderosa pine site, which significantly reduced loss of shallow root function. In the young ponderosa pine stand, where little HR occurred, the water potential in the upper soil layers fell to about -2.8 MPa, which severely impaired root functioning and limited recovery when the fall rains returned. In both species, daily maximum g(s) decreased linearly with increasing root PLC, suggesting that root xylem embolism acted in concert with stomata to limit water loss, thereby maintaining minimum leaf water potential above critical values. HR appears to be an important mechanism for maintaining shallow root function during drought and preventing total stomatal closure.

  1. Lessons from the fires of 2000: Post-fire heterogeneity in ponderosa pine forests

    Science.gov (United States)

    Kotliar, Natasha B.; Haire, Sandra L.; Key, Carl H.; Omni, Phillip N.; Joyce, Linda A.

    2003-01-01

    We evaluate burn-severity patterns for six burns that occurred in the southern Rocky Mountains and the Colorado Plateau in 2000. We compare the results of two data sources: Burned Area Rehabilitations Teams (BAER) and a spatial burnseverity model derived from satellite imagery (the Normalized Burn Ratio; NBR). BAER maps tended to overestimate area of severe burns and underestimate area of moderate-severity burns relative to NBR maps. Low elevation and more southern ponderosa pine burns were predominantly understory burns, whereas burns at higher elevations and farther north had a greater component of high-severity burns. Thus, much, if not most, of the area covered by these burns appears to be consistent with historic burns and contributes to healthy functioning ecosystems.

  2. Presence of carbaryl in the smoke of treated lodgepole and ponderosa pine bark

    Science.gov (United States)

    Peterson, Chris J.; Costello, Sheryl L.

    2013-02-01

    Lodgepole and ponderosa pine trees were treated with a 2% carbaryl solution at recreational areas near Fort Collins, CO, in June 2010 as a prophylactic bole spray against the mountain pine beetle. Bark samples from treated and untreated trees were collected one day following application and at 4-month intervals for one year. The residual amount of carbaryl was determined, and bark samples were burned to examine the smoke for the active ingredient. Smoke recovered from spiked bark samples showed a very high correlation between the treated rate and the concentration recovered from the smoke. Residual carbaryl on the bark was relatively stable throughout the study and carbaryl was detected in the smoke throughout the duration of the test.

  3. Response of young ponderosa pines, shrubs, and grasses to two release treatments. Forest Service research note

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, P.M.; Everest, G.A.

    1996-07-01

    To release a young pine plantation on a medium site in central California, herbicides and mulches were applied soon after planting to study their effectiveness. Bearclover is an aggressive shrub species that resprouts from rhizomes after disturbance, and must be controlled if young conifer seedlings are to become established. After 4 years, resprouting bearclover plants numbered 282,000 per acre in the control, but less than 4,000 per acre in the plots treated by herbicides. Mean foliar cover was 63 percent versus 1 percent for control and herbicide plots, respectively. Ponderosa pine seedlings were significantly taller, had larger mean diameters, and survived better in the herbicide treatment than counterparts in mulched plots and control. The 5-foot square mulches were ineffective for controlling bearclover. Cheatgrass invaded the plantation in the second year, and after 2 more years became abundant in herbicide plots and plentiful in the control.

  4. Carbon and water fluxes from ponderosa pine forests disturbed by wildfire and thinning.

    Science.gov (United States)

    Dore, S; Kolb, T E; Montes-Helu, M; Eckert, S E; Sullivan, B W; Hungate, B A; Kaye, J P; Hart, S C; Koch, G W; Finkral, A

    2010-04-01

    Disturbances alter ecosystem carbon dynamics, often by reducing carbon uptake and stocks. We compared the impact of two types of disturbances that represent the most likely future conditions of currently dense ponderosa pine forests of the southwestern United States: (1) high-intensity fire and (2) thinning, designed to reduce fire intensity. High-severity fire had a larger impact on ecosystem carbon uptake and storage than thinning. Total ecosystem carbon was 42% lower at the intensely burned site, 10 years after burning, than at the undisturbed site. Eddy covariance measurements over two years showed that the burned site was a net annual source of carbon to the atmosphere whereas the undisturbed site was a sink. Net primary production (NPP), evapotranspiration (ET), and water use efficiency were lower at the burned site than at the undisturbed site. In contrast, thinning decreased total ecosystem carbon by 18%, and changed the site from a carbon sink to a source in the first posttreatment year. Thinning also decreased ET, reduced the limitation of drought on carbon uptake during summer, and did not change water use efficiency. Both disturbances reduced ecosystem carbon uptake by decreasing gross primary production (55% by burning, 30% by thinning) more than total ecosystem respiration (TER; 33-47% by burning, 18% by thinning), and increased the contribution of soil carbon dioxide efflux to TER. The relationship between TER and temperature was not affected by either disturbance. Efforts to accurately estimate regional carbon budgets should consider impacts on carbon dynamics of both large disturbances, such as high-intensity fire, and the partial disturbance of thinning that is often used to prevent intense burning. Our results show that thinned forests of ponderosa pine in the southwestern United States are a desirable alternative to intensively burned forests to maintain carbon stocks and primary production.

  5. Forest thinning and soil respiration in a ponderosa pine plantation in the Sierra Nevada.

    Science.gov (United States)

    Tang, Jianwu; Qi, Ye; Xu, Ming; Misson, Laurent; Goldstein, Allen H

    2005-01-01

    Soil respiration is controlled by soil temperature, soil water, fine roots, microbial activity, and soil physical and chemical properties. Forest thinning changes soil temperature, soil water content, and root density and activity, and thus changes soil respiration. We measured soil respiration monthly and soil temperature and volumetric soil water continuously in a young ponderosa pine (Pinus ponderosa Dougl. ex P. Laws. & C. Laws.) plantation in the Sierra Nevada Mountains in California from June 1998 to May 2000 (before a thinning that removed 30% of the biomass), and from May to December 2001 (after thinning). Thinning increased the spatial homogeneity of soil temperature and respiration. We conducted a multivariate analysis with two independent variables of soil temperature and water and a categorical variable representing the thinning event to simulate soil respiration and assess the effect of thinning. Thinning did not change the sensitivity of soil respiration to temperature or to water, but decreased total soil respiration by 13% at a given temperature and water content. This decrease in soil respiration was likely associated with the decrease in root density after thinning. With a model driven by continuous soil temperature and water time series, we estimated that total soil respiration was 948, 949 and 831 g C m(-2) year(-1) in the years 1999, 2000 and 2001, respectively. Although thinning reduced soil respiration at a given temperature and water content, because of natural climate variability and the thinning effect on soil temperature and water, actual cumulative soil respiration showed no clear trend following thinning. We conclude that the effect of forest thinning on soil respiration is the combined result of a decrease in root respiration, an increase in soil organic matter, and changes in soil temperature and water due to both thinning and interannual climate variability.

  6. Ponderosa pine snag densities following multiple fires in the Gila Wilderness, New Mexico

    Science.gov (United States)

    Holden, Z.A.; Morgan, P.; Rollins, M.G.; Wright, R.G.

    2006-01-01

    Fires create and consume snags (standing dead trees), an important structural and ecological component of ponderosa pine forests. The effects of repeated fires on snag densities in ponderosa pine forests of the southwestern USA have not been studied. Line intercept sampling was used to estimate snag densities in areas of the Gila Wilderness that had burned one to three times under Wildland Fire Use for Resource Benefit (WFU), a fire management policy implemented since 1974 aimed at restoring natural fire regimes. Twenty randomly located transects were measured in areas burned since 1946; six in once-burned areas, six in twice-burned areas and eight in thrice-burned areas. The mean density ?? standard errors of large (>47.5 cm dbh) snags for areas that burned once, twice and thrice was 7.0 ?? 2.7, 4.4 ?? 1.1 and 4.1 ?? 1.3 snags/ha, respectively. Differences in snag densities between once- and multiple-burned areas were significant (F-test; p < 0.05). There was no significant difference in density of large snags between twice- and thrice-burned areas. Proportions of type 1 snags (recently created) were higher in once- and twice-burned areas than in areas that burned three times, likely reflecting high tree mortality and snag recruitment resulting from an initial entry fire. Type 3 snags (charred by previous fire) were more abundant in areas that burned multiple times. The lack of differences in snag densities between areas that burned two and three times suggests that repeated fires leave many snags standing. The increasing proportion of type 3 snags with repeated fires supports this conclusion. ?? 2005 Elsevier B.V. All rights reserved.

  7. Multiple View Zenith Angle Observations of Reflectance From Ponderosa Pine Stands

    Science.gov (United States)

    Johnson, Lee F.; Lawless, James G. (Technical Monitor)

    1994-01-01

    Reflectance factors (RF(lambda)) from dense and sparse ponderosa pine (Pinus ponderosa) stands, derived from radiance data collected in the solar principal plane by the Advanced Solid-State Array Spectro-radiometer (ASAS), were examined as a function of view zenith angle (theta(sub v)). RF(lambda) was maximized with theta(sub v) nearest the solar retrodirection, and minimized near the specular direction throughout the ASAS spectral region. The dense stand had much higher RF anisotropy (ma)dmurn RF is minimum RF) in the red region than did the sparse stand (relative differences of 5.3 vs. 2.75, respectively), as a function of theta(sub v), due to the shadow component in the canopy. Anisotropy in the near-infrared (NIR) was more similar between the two stands (2.5 in the dense stand and 2.25 in the sparse stand); the dense stand exhibited a greater hotspot effect than 20 the sparse stand in this spectral region. Two common vegetation transforms, the NIR/red ratio and the normalized difference vegetation index (NDVI), both showed a theta(sub v) dependence for the dense stand. Minimum values occurred near the retrodirection and maximum values occurred near the specular direction. Greater relative differences were noted for the NIR/red ratio (2.1) than for the NDVI (1.3). The sparse stand showed no obvious dependence on theta(sub v) for either transform, except for slightly elevated values toward the specular direction.

  8. Restoring forest structure and process stabilizes forest carbon in wildfire-prone southwestern ponderosa pine forests.

    Science.gov (United States)

    Hurteau, Matthew D; Liang, Shuang; Martin, Katherine L; North, Malcolm P; Koch, George W; Hungate, Bruce A

    2016-03-01

    Changing climate and a legacy of fire-exclusion have increased the probability of high-severity wildfire, leading to an increased risk of forest carbon loss in ponderosa pine forests in the southwestern USA. Efforts to reduce high-severity fire risk through forest thinning and prescribed burning require both the removal and emission of carbon from these forests, and any potential carbon benefits from treatment may depend on the occurrence of wildfire. We sought to determine how forest treatments alter the effects of stochastic wildfire events on the forest carbon balance. We modeled three treatments (control, thin-only, and thin and burn) with and without the occurrence of wildfire. We evaluated how two different probabilities of wildfire occurrence, 1% and 2% per year, might alter the carbon balance of treatments. In the absence of wildfire, we found that thinning and burning treatments initially reduced total ecosystem carbon (TEC) and increased net ecosystem carbon balance (NECB). In the presence of wildfire, the thin and burn treatment TEC surpassed that of the control in year 40 at 2%/yr wildfire probability, and in year 51 at 1%/yr wildfire probability. NECB in the presence of wildfire showed a similar response to the no-wildfire scenarios: both thin-only and thin and burn treatments increased the C sink. Treatments increased TEC by reducing both mean wildfire severity and its variability. While the carbon balance of treatments may differ in more productive forest types, the carbon balance benefits from restoring forest structure and fire in southwestern ponderosa pine forests are clear.

  9. Community occupancy responses of small mammals to restoration treatments in ponderosa pine forests, northern Arizona, USA.

    Science.gov (United States)

    Kalies, E L; Dickson, B G; Chambers, C L; Covington, W W

    2012-01-01

    In western North American conifer forests, wildfires are increasing in frequency and severity due to heavy fuel loads that have accumulated after a century of fire suppression. Forest restoration treatments (e.g., thinning and/or burning) are being designed and implemented at large spatial and temporal scales in an effort to reduce fire risk and restore forest structure and function. In ponderosa pine (Pinus ponderosa) forests, predominantly open forest structure and a frequent, low-severity fire regime constituted the evolutionary environment for wildlife that persisted for thousands of years. Small mammals are important in forest ecosystems as prey and in affecting primary production and decomposition. During 2006-2009, we trapped eight species of small mammals at 294 sites in northern Arizona and used occupancy modeling to determine community responses to thinning and habitat features. The most important covariates in predicting small mammal occupancy were understory vegetation cover, large snags, and treatment. Our analysis identified two generalist species found at relatively high occupancy rates across all sites, four open-forest species that responded positively to treatment, and two dense-forest species that responded negatively to treatment unless specific habitat features were retained. Our results indicate that all eight small mammal species can benefit from restoration treatments, particularly if aspects of their evolutionary environment (e.g., large trees, snags, woody debris) are restored. The occupancy modeling approach we used resulted in precise species-level estimates of occupancy in response to habitat attributes for a greater number of small mammal species than in other comparable studies. We recommend our approach for other studies faced with high variability and broad spatial and temporal scales in assessing impacts of treatments or habitat alteration on wildlife species. Moreover, since forest planning efforts are increasingly focusing on

  10. Sensitivity of ring growth and carbon allocation to climatic variation vary within ponderosa pine trees.

    Science.gov (United States)

    Kerhoulas, Lucy P; Kane, Jeffrey M

    2012-01-01

    Most dendrochronological studies focus on cores sampled from standard positions (main stem, breast height), yet vertical gradients in hydraulic constraints and priorities for carbon allocation may contribute to different growth sensitivities with position. Using cores taken from five positions (coarse roots, breast height, base of live crown, mid-crown branch and treetop), we investigated how radial growth sensitivity to climate over the period of 1895-2008 varies by position within 36 large ponderosa pines (Pinus ponderosa Dougl.) in northern Arizona. The climate parameters investigated were Palmer Drought Severity Index, water year and monsoon precipitation, maximum annual temperature, minimum annual temperature and average annual temperature. For each study tree, we generated Pearson correlation coefficients between ring width indices from each position and six climate parameters. We also investigated whether the number of missing rings differed among positions and bole heights. We found that tree density did not significantly influence climatic sensitivity to any of the climate parameters investigated at any of the sample positions. Results from three types of analyses suggest that climatic sensitivity of tree growth varied with position height: (i) correlations of radial growth and climate variables consistently increased with height; (ii) model strength based on Akaike's information criterion increased with height, where treetop growth consistently had the highest sensitivity and coarse roots the lowest sensitivity to each climatic parameter; and (iii) the correlation between bole ring width indices decreased with distance between positions. We speculate that increased sensitivity to climate at higher positions is related to hydraulic limitation because higher positions experience greater xylem tensions due to gravitational effects that render these positions more sensitive to climatic stresses. The low sensitivity of root growth to all climatic variables

  11. Bole girdling affects metabolic properties and root, trunk and branch hydraulics of young ponderosa pine trees.

    Science.gov (United States)

    Domec, Jean-Christophe; Pruyn, Michele L

    2008-10-01

    Effects of trunk girdling on seasonal patterns of xylem water status, water transport and woody tissue metabolic properties were investigated in ponderosa pine (Pinus ponderosa Dougl. ex P. Laws.) trees. At the onset of summer, there was a sharp decrease in stomatal conductance (g(s)) in girdled trees followed by a full recovery after the first major rainfall in September. Eliminating the root as a carbohydrate sink by girdling induced a rapid reversible reduction in g(s). Respiratory potential (a laboratory measure of tissue-level respiration) increased above the girdle (branches and upper trunk) and decreased below the girdle (lower trunk and roots) relative to control trees during the growing season, but the effect was reversed after the first major rainfall. The increase in branch respiratory potential induced by girdling suggests that the decrease in g(s) was caused by the accumulation of carbohydrates above the girdle, which is consistent with an observed increase in leaf mass per area in the girdled trees. Trunk girdling did not affect native xylem embolism or xylem conductivity. Both treated and control trunks experienced loss of xylem conductivity ranging from 10% in spring to 30% in summer. Girdling reduced xylem growth and sapwood to leaf area ratio, which in turn reduced branch leaf specific conductivity (LSC). The girdling-induced reductions in g(s) and transpiration were associated with a decrease in leaf hydraulic conductance. Two years after girdling, when root-to-shoot phloem continuity had been restored, girdled trees had a reduced density of new wood, which increased xylem conductivity and whole-tree LSC, but also vulnerability to embolism.

  12. Carbon Stocks and Climate Change: Management Implications in Northern Arizona Ponderosa Pine Forests

    Directory of Open Access Journals (Sweden)

    Benjamin Bagdon

    2014-04-01

    Full Text Available Researchers have observed climate-driven shifts of forest types to higher elevations in the Southwestern US and predict further migration coupled with large-scale mortality events proportional to increases in radiative forcing. Range contractions of forests are likely to impact the total carbon stored within a stand. This study examines the dynamics of Pinus ponderosa stands under three climate change scenarios in Northern Arizona using the Climate Forest Vegetation Simulator (Climate-FVS model to project changes in carbon pools. A sample of 90 stands were grouped according to three elevational ranges; low- (1951 to 2194 m, mid- (2194 to 2499 m, and high- (2499 to 2682 m. elevation stands. Growth, mortality, and carbon stores were simulated in the Climate-FVS over a 100 year timespan. We further simulated three management scenarios for each elevational gradient and climate scenario. Management included (1 a no-management scenario, (2 an intensive-management scenario characterized by thinning from below to a residual basal area (BA of 18 m2/ha in conjunction with a prescribed burn every 10 years, and (3 a moderate-management scenario characterized by a thin-from-below treatment to a residual BA of 28 m2/ha coupled with a prescribed burn every 20 years. Results indicate that any increase in aridity due to climate change will produce substantial mortality throughout the elevational range of ponderosa pine stands, with lower elevation stands projected to experience the most devastating effects. Management was only effective for the intensive-management scenario; stands receiving this treatment schedule maintained moderately consistent levels of basal area and demonstrated a higher level of resilience to climate change relative to the two other management scenarios. The results of this study indicate that management can improve resiliency to climate change, however, resource managers may need to employ more intensive thinning treatments than

  13. Investigation of the current population of Dendroctonus micans (Kugelann (Coleoptera: Curculionidae and colonization rate of Rhizophagus grandis Gyllenhal (Coleoptera: Monotomidae in spruce forests of Artvin

    Directory of Open Access Journals (Sweden)

    Hazan Alkan Akıncı

    2017-04-01

    Full Text Available In this study, current population of Dendroctonus micans (Kugelann (Coleoptera: Curculionidae, and colonization status of its specific predator Rhizophagus grandis Gyllenhal (Coleoptera: Monotomidae in spruce forests of Artvin were investigated. Field works were conducted in a total of 30 sampling plots and along 20 transects. Sampling plots were 30 × 10 m in size and transects 50 m long. Presently, D. micans has a “very low infestation” rate in Artvin spruce forests and D. micans infestation rate is 4.1 times lower than the early 2000s. The trees at the stands edges were attacked more than trees in stand closure. All the larval galleries of D. micans were colonized by R. grandis. R. grandis could colonize larval galleries of its prey even in endemic conditions.

  14. 红脂大小蠹发生危害及其防治%Occurrence and control of Dendroctonus valens LeConte

    Institute of Scientific and Technical Information of China (English)

    刘光生; 王俊华; 韩惠娟; 王建平

    2003-01-01

    @@ 红脂大小蠹(Dendroctonus valens Leconte),属鞘翅目,小蠹科,大小蠹属,是油松林毁灭性害虫之一.1998年山西省暴发危害,受灾面积约200万hm2,吕梁地区受害面积11万hm2.为了科学、有效地防治此虫保护森林,于2000~2002年在交城县会立乡关帝山林区定点对此虫生物学特性,及其与物候关系进行了调查研究.

  15. Pest risk analysis of red turpentine beetle(Dendroctonus valens)%森林有害生物红脂大小蠹的危险性分析

    Institute of Scientific and Technical Information of China (English)

    宋玉双; 杨安龙; 何嫩江

    2000-01-01

    该文参照国际上有害生物危险性分析(Pest Risk Analysis,简写PRA)方法,从有害生物的国内分布状况、潜在的危害性、寄主植物的经济重要性、传播扩散的可能性以及危险性的管理难度等几个方面进行定性和定量分析,对红脂大小蠹Dendroctonus valens的危险性做出综合评价.评价结果表明红脂大小蠹在我国属于高度危险的森林有害生物.

  16. The experimentation of pharmic prevention and cure on Dendroctonus valens%红脂大小蠹药物防治试验

    Institute of Scientific and Technical Information of China (English)

    孙启洋; 姚印随; 吕松江; 张文清

    2005-01-01

    本文采用塑料布密闭熏杀、毒签插孔和虫孔注药三种方法分别对红脂大小蠹Dendroctonus valens Leconte新侵入活立木和伐桩进行了防治试验.结果表明,每株投放3~5片磷化铝进行密闭熏杀、新侵入活立木和伐桩进行毒签插孔、甲胺磷10倍液进行虫孔注药防治,杀虫效果均较理想;毒签插孔、虫孔注药防治费用明显低于塑料布密闭熏杀.

  17. A review of precipitation and temperature control on seedling emergence and establishment for ponderosa and lodgepole pine forest regeneration

    Science.gov (United States)

    Petrie, Matthew; Wildeman, A.M.; Bradford, John B.; Hubbard, R.M.; Lauenroth, W.K.

    2016-01-01

    The persistence of ponderosa pine and lodgepole pine forests in the 21st century depends to a large extent on how seedling emergence and establishment are influenced by driving climate and environmental variables, which largely govern forest regeneration. We surveyed the literature, and identified 96 publications that reported data on dependent variables of seedling emergence and/or establishment and one or more independent variables of air temperature, soil temperature, precipitation and moisture availability. Our review suggests that seedling emergence and establishment for both species is highest at intermediate temperatures (20 to 25 °C), and higher precipitation and higher moisture availability support a higher percentage of seedling emergence and establishment at daily, monthly and annual timescales. We found that ponderosa pine seedlings may be more sensitive to temperature fluctuations whereas lodgepole pine seedlings may be more sensitive to moisture fluctuations. In a changing climate, increasing temperatures and declining moisture availability may hinder forest persistence by limiting seedling processes. Yet, only 23 studies in our review investigated the effects of driving climate and environmental variables directly. Furthermore, 74 studies occurred in a laboratory or greenhouse, which do not often replicate the conditions experienced by tree seedlings in a field setting. It is therefore difficult to provide strong conclusions on how sensitive emergence and establishment in ponderosa and lodgepole pine are to these specific driving variables, or to investigate their potential aggregate effects. Thus, the effects of many driving variables on seedling processes remain largely inconclusive. Our review stresses the need for additional field and laboratory studies to better elucidate the effects of driving climate and environmental variables on seedling emergence and establishment for ponderosa and lodgepole pine.

  18. Resource Limitations Influence Growth and Vigor of Idaho Fescue, a Common Understory Species in Pacific Northwest Ponderosa Pine Forests

    Directory of Open Access Journals (Sweden)

    Craig A. Carr

    2016-12-01

    Full Text Available Alterations in under-canopy resource availability associated with elevated ponderosa pine (Pinus ponderosa Dougl. abundance can negatively influence understory vegetation. Experimental evidence linking under-canopy resource availability and understory vegetation is scarce. Yet this information would be beneficial in developing management strategies to recover desired understory species. We tested the effects of varying nitrogen (N and light availability on Idaho fescue (Festuca idahoensis Elmer, the dominant understory species in ponderosa pine/Idaho fescue plant associations in eastern Oregon. In a greenhouse experiment, two levels of N (50 kg∙N∙ha−1 and 0 kg∙N∙ha−1 and shade (80% shade and 0% shade were applied in a split-plot design to individual potted plants grown in soil collected from high abundance pine stands. Plants grown in unshaded conditions produced greater root (p = 0.0027 and shoot (p = 0.0017 biomass and higher cover values (p = 0.0378 compared to those in the shaded treatments. The addition of N had little effect on plant growth (p = 0.1602, 0.5129, and 0.0853 for shoot biomass, root biomass, and cover, respectively, suggesting that soils in high-density ponderosa pine stands that lack understory vegetation were not N deficient and Idaho fescue plants grown in these soils were not N limited. Management activities that increase under-canopy light availability will promote the conditions necessary for Idaho fescue recovery. However, successful restoration may be constrained by a lack of residual fescue or the invasion of more competitive understory vegetation.

  19. Effects of acidic fog on seedlings of Pinus ponderosa and Abies concolor: foliar injury, physiological and biochemical responses.

    Science.gov (United States)

    Takemoto, B K; Bytnerowicz, A

    1993-01-01

    Seedlings of Pinus ponderosa (ponderosa pine) and Abies concolor (white fir) were exposed to acidic fog (pH 2.0, 3.0 or 4.0) in open-field plots for six weeks. The two species exhibited dissimilar injury responses; neither current year nor previous year needles of ponderosa pine were injured by pH 2.0 fog, but current year needles exhibited higher membrane permeability responses (i.e. needle extract conductivity, K+ concentration). In comparison, both needle age classes in white fir were significantly injured by pH 2.0 fog, but no significant effects on membrane permeability were observed. For both species, whole-study average rates of net photosynthesis in previous year needles were lower in plants exposed to pH 2.0 fog than in plants treated with pH 4.0 fog. While decreased process rates coincided with leaf necrosis in white fir, stomatal closure appeared to be the mechanism of inhibition in ponderosa pine with pH 2.0 fog (i.e. no visible injury). The findings of the present study provide evidence that frequent applications of highly acidic fog (i.e. pH 2.0-3.0) can cause temporal alterations in membrane permeability and gas exchange rates in western conifer seedlings, in the presence or absence of visible injury. However, because incipient effects on other measures of foliage health were species-specific (i.e. concentrations of starch, photosynthetic pigments, inorganic nutrients), a general mechanism of phytotoxicity could not be identified.

  20. Trends in Snag Populations in Drought-Stressed Mixed-Conifer and Ponderosa Pine Forests (1997–2007

    Directory of Open Access Journals (Sweden)

    Joseph L. Ganey

    2012-01-01

    Full Text Available Snags provide important biological legacies, resources for numerous species of native wildlife, and contribute to decay dynamics and ecological processes in forested ecosystems. We monitored trends in snag populations from 1997 to 2007 in drought-stressed mixed-conifer and ponderosa pine (Pinus ponderosa Dougl. ex Laws forests, northern Arizona. Median snag density increased by 75 and 90% in mixed-conifer and ponderosa pine forests, respectively, over this time period. Increased snag density was driven primarily by a large pulse in drought-mediated tree mortality from 2002 to 2007, following a smaller pulse from 1997 to 2002. Decay-class composition and size-class composition of snag populations changed in both forest types, and species composition changed in mixed-conifer forest. Increases in snag abundance may benefit some species of native wildlife in the short-term by providing increased foraging and nesting resources, but these increases may be unsustainable in the long term. Observed changes in snag recruitment and fall rates during the study illustrate the difficulty involved in modeling dynamics of those populations in an era of climate change and changing land management practices.

  1. Late Holocene geomorphic record of fire in ponderosa pine and mixed-conifer forests, Kendrick Mountain, northern Arizona, USA

    Science.gov (United States)

    Jenkins, S.E.; Hull, Sieg C.; Anderson, D.E.; Kaufman, D.S.; Pearthree, P.A.

    2011-01-01

    Long-term fire history reconstructions enhance our understanding of fire behaviour and associated geomorphic hazards in forested ecosystems. We used 14C ages on charcoal from fire-induced debris-flow deposits to date prehistoric fires on Kendrick Mountain, northern Arizona, USA. Fire-related debris-flow sedimentation dominates Holocene fan deposition in the study area. Radiocarbon ages indicate that stand-replacing fire has been an important phenomenon in late Holocene ponderosa pine (Pinus ponderosa) and ponderosa pine-mixed conifer forests on steep slopes. Fires have occurred on centennial scales during this period, although temporal hiatuses between recorded fires vary widely and appear to have decreased during the past 2000 years. Steep slopes and complex terrain may be responsible for localised crown fire behaviour through preheating by vertical fuel arrangement and accumulation of excessive fuels. Holocene wildfire-induced debris flow events occurred without a clear relationship to regional climatic shifts (decadal to millennial), suggesting that interannual moisture variability may determine fire year. Fire-debris flow sequences are recorded when (1) sufficient time has passed (centuries) to accumulate fuels; and (2) stored sediment is available to support debris flows. The frequency of reconstructed debris flows should be considered a minimum for severe events in the study area, as fuel production may outpace sediment storage. ?? IAWF 2011.

  2. Areas of Agreement and Disagreement Regarding Ponderosa Pine and Mixed Conifer Forest Fire Regimes: A Dialogue with Stevens et al.

    Science.gov (United States)

    Odion, Dennis C; Hanson, Chad T; Baker, William L; DellaSala, Dominick A; Williams, Mark A

    2016-01-01

    In a recent PLOS ONE paper, we conducted an evidence-based analysis of current versus historical fire regimes and concluded that traditionally defined reference conditions of low-severity fire regimes for ponderosa pine (Pinus ponderosa) and mixed-conifer forests were incomplete, missing considerable variability in forest structure and fire regimes. Stevens et al. (this issue) agree that high-severity fire was a component of these forests, but disagree that one of the several sources of evidence, stand age from a large number of forest inventory and analysis (FIA) plots across the western USA, support our findings that severe fire played more than a minor role ecologically in these forests. Here we highlight areas of agreement and disagreement about past fire, and analyze the methods Stevens et al. used to assess the FIA stand-age data. We found a major problem with a calculation they used to conclude that the FIA data were not useful for evaluating fire regimes. Their calculation, as well as a narrowing of the definition of high-severity fire from the one we used, leads to a large underestimate of conditions consistent with historical high-severity fire. The FIA stand age data do have limitations but they are consistent with other landscape-inference data sources in supporting a broader paradigm about historical variability of fire in ponderosa and mixed-conifer forests than had been traditionally recognized, as described in our previous PLOS paper.

  3. Areas of Agreement and Disagreement Regarding Ponderosa Pine and Mixed Conifer Forest Fire Regimes: A Dialogue with Stevens et al.

    Directory of Open Access Journals (Sweden)

    Dennis C Odion

    Full Text Available In a recent PLOS ONE paper, we conducted an evidence-based analysis of current versus historical fire regimes and concluded that traditionally defined reference conditions of low-severity fire regimes for ponderosa pine (Pinus ponderosa and mixed-conifer forests were incomplete, missing considerable variability in forest structure and fire regimes. Stevens et al. (this issue agree that high-severity fire was a component of these forests, but disagree that one of the several sources of evidence, stand age from a large number of forest inventory and analysis (FIA plots across the western USA, support our findings that severe fire played more than a minor role ecologically in these forests. Here we highlight areas of agreement and disagreement about past fire, and analyze the methods Stevens et al. used to assess the FIA stand-age data. We found a major problem with a calculation they used to conclude that the FIA data were not useful for evaluating fire regimes. Their calculation, as well as a narrowing of the definition of high-severity fire from the one we used, leads to a large underestimate of conditions consistent with historical high-severity fire. The FIA stand age data do have limitations but they are consistent with other landscape-inference data sources in supporting a broader paradigm about historical variability of fire in ponderosa and mixed-conifer forests than had been traditionally recognized, as described in our previous PLOS paper.

  4. A comparison of the metabolism of the abortifacient compounds from Ponderosa pine needles in conditioned versus naive cattle.

    Science.gov (United States)

    Welch, K D; Gardner, D R; Pfister, J A; Panter, K E; Zieglar, J; Hall, J O

    2012-12-01

    Isocupressic acid (ICA) is the abortifacient compound in ponderosa pine (Pinus ponderosa L.) needles, which can cause late-term abortions in cattle (Bos taurus). However, cattle rapidly metabolize ICA to agathic acid (AGA) and subsequent metabolites. When pine needles are dosed orally to cattle, no ICA is detected in their serum, whereas AGA is readily detected. Recent research has demonstrated that AGA is also an abortifacient compound in cattle. The observation has been made that when cattle are dosed with labdane acids for an extended time, the concentration of AGA in serum increases for 1 to 2 d but then decreases to baseline after 5 to 6 d even though they are still being dosed twice daily. Therefore, in this study we investigated whether cattle conditioned to pine needles metabolize ICA, and its metabolites, faster than naïve cattle. Agathic acid was readily detected in the serum of naïve cattle fed ponderosa pine needles, whereas very little AGA was detected in the serum of cattle conditioned to pine needles. We also compared the metabolism of ICA in vitro using rumen cultures from pine-needle-conditioned and naïve cattle. In the rumen cultures from conditioned cattle, AGA concentrations were dramatically less than rumen cultures from naïve cattle. Thus, an adaptation occurs to cattle conditioned to pine needles such that the metabolism AGA by the rumen microflora is altered.

  5. Stomata open at night in pole-sized and mature ponderosa pine: implications for O3 exposure metrics.

    Science.gov (United States)

    Grulke, N E; Alonso, R; Nguyen, T; Cascio, C; Dobrowolski, W

    2004-09-01

    Ponderosa pine (Pinus ponderosa Dougl. ex Laws.) is widely distributed in the western USA. We report the lack of stomatal closure at night in early summer for ponderosa pine at two of three sites investigated. Trees at a third site with lower nitrogen dioxide and nitric acid exposure, but greater drought stress, had slightly open stomata at night in early summer but closed stomata at night for the rest of the summer. The three sites had similar background ozone exposure during the summer of measurement (2001). Nighttime stomatal conductance (gs) ranged from one tenth to one fifth that of maximum daytime values. In general, pole-sized trees ( 250 years old). In late summer, nighttime gs was low (< 3.0 mmol H2O m(-2) s(-1)) for both tree size classes at all sites. Measurable nighttime gs has also been reported in other conifers, but the values we observed were higher. In June, nighttime ozone (O3) uptake accounted for 9, 5 and 3% of the total daily O3 uptake of pole-sized trees from west to east across the San Bernardino Mountains. In late summer, O3 uptake at night was < 2% of diel uptake at all sites. Nocturnal O3 uptake may contribute to greater oxidant injury development, especially in pole-sized trees in early summer.

  6. Progress report for the project: Comparison of the response of mature branches and seedlings of Pinus ponderosa to atmospheric pollution

    Energy Technology Data Exchange (ETDEWEB)

    Houpis, J.L.J.; Anderson, P.D.; Benes, S.E.; Phelps, S.P.; Loeffler, A.T.

    1990-09-01

    This progress report details Lawrence Livermore National Laboratory's (LLNL) performance regarding the projects Comparison of the Response of Mature Branches and Seedlings of Pinus ponderosa to Atmospheric Pollution'' and Effects of Ozone, acid Precipitation, and Their Interactions on Mature Branches and Seedlings of Ponderosa Pine'' for the months of November 1989 to June 1990. During the last eight months, we have initiated ozone and acid precipitation exposures, and we began intensive growth, morphological, and physiological measurements. During these major physiological measurement periods, we measured photosynthesis, transpiration, stomatal conductance, respiration, antioxidant activity, pigmentation, and foliar nutrient concentration. We have also concluded the analysis of our branch autonomy experiment, which we conducted in the fall. We determined that virtually no carbon is exported among branches in close proximity to one another. This conclusion assists in validating the approach of using branches and branch exposure chambers as a means of assessing the effects of air pollution on mature trees of Ponderosa pine. 6 refs., 4 figs., 3 tabs.

  7. Three studies on ponderosa pine management on the Warm Springs Indian Reservation: stocking control in uneven-aged stands, forest products from fire-damage trees, and fuels reduction

    Science.gov (United States)

    John V. Arena

    2005-01-01

    Over 60,000 acres of ponderosa pine (Pinus ponderosa P. and C. Lawson) forest on the Warm Springs Indian Reservation (WSIR) in Oregon are managed using an uneven-age system. Three on-going studies on WSIR address current issues in the management of pine forests: determining levels of growing stock for uneven-age management, fire effects on wood...

  8. Identification and Quarantine for 3 Species Dendroctonus Erichson in China%浅析我国分布的3种大小蠹的识别与检疫管理

    Institute of Scientific and Technical Information of China (English)

    吴中虹

    2011-01-01

    对红脂大小蠹、华山松大小蠹和云杉大小蠹的形态特征、为害寄主以及危害症状进行了比较分析,提出了检疫管理措施,为进境口岸针对性检疫和保护我国的林木资源提供参考。%This paper compares the morphological characteristics and harm characteristics of Dendroctonus valens,D, armandi and D. micans. Combined with the practical situation of port inspection and quarantine, the paper proposes thequarantine measures against the three species Dendroctonus Erichson.

  9. Ectomycorrhizal fungi associated with ponderosa pine and Douglas-fir: a comparison of species richness in native western North American forests and Patagonian plantations from Argentina.

    Science.gov (United States)

    Barroetaveña, C; Cázares, E; Rajchenberg, M

    2007-07-01

    The putative ectomycorrhizal fungal species registered from sporocarps associated with ponderosa pine and Douglas-fir forests in their natural range distribution (i.e., western Canada, USA, and Mexico) and from plantations in south Argentina and other parts of the world are listed. One hundred and fifty seven taxa are reported for native ponderosa pine forests and 514 taxa for native Douglas-fir forests based on available literature and databases. A small group of genera comprises a high proportion of the species richness for native Douglas-fir (i.e., Cortinarius, Inocybe, and Russula), whereas in native ponderosa pine, the species richness is more evenly distributed among several genera. The comparison between ectomycorrhizal species richness associated with both trees in native forests and in Patagonia (Argentina) shows far fewer species in the latter, with 18 taxa for the ponderosa pine and 15 for the Douglas-fir. Epigeous species richness is clearly dominant in native Douglas-fir, whereas a more balanced relation epigeous/hypogeous richness is observed for native ponderosa pine; a similar trend was observed for Patagonian plantations. Most fungi in Patagonian Douglas-fir plantations have not been recorded in plantations elsewhere, except Suillus lakei and Thelephora terrestris, and only 56% of the fungal taxa recorded in Douglas-fir plantations around the world are known from native forests, the other taxa being new associations for this host, suggesting that new tree + ectomycorrhizal fungal taxa associations are favored in artificial situations as plantations.

  10. Homeostatic maintenance of ponderosa pine gas exchange in response to stand density changes.

    Science.gov (United States)

    McDowell, Nate G; Adams, Henry D; Bailey, John D; Hess, Marcey; Kolb, Thomas E

    2006-06-01

    Homeostatic maintenance of gas exchange optimizes carbon gain per water loss. Homeostasis is regulated by short-term physiological and long-term structural mechanisms, both of which may respond to changes in resource availability associated with competition. Therefore, stand density regulation via silvicultural manipulations may facilitate growth and survival through mechanisms operating at both short and long timescales. We investigated the responses of ponderosa pine (Pinus ponderosa) to stand basal area manipulations in Arizona, USA. Stand basal area was manipulated to seven replicated levels in 1962 and was maintained for four decades by decadal thinning. We measured basal area increment (BAI) to assess the response and sustainability of wood growth, carbon isotope discrimination (A) inferred from annual rings to assess the response of crown gas exchange, and ratios of leaf area to sapwood area (A(l):A(s)) to assess longer term structural acclimation. Basal area treatments increased soil water potential (r2 = 0.99) but did not affect photosynthetic capacity. BAI increased within two years of thinning, and the 40-year mean BAI was negatively correlated with stand basal area (r2 = 0.98). delta was negatively correlated with stand basal area for years 5 through 12 after thinning (r2 = 0.90). However, delta was relatively invariant with basal area for the period 13-40 years after initial thinning despite maintenance of treatment basal areas via repeated decadal thinnings. Independent gas exchange measurements verified that the ratio of photosynthesis to stomatal conductance was invariant with basal area, but absolute values of both were elevated at lower basal areas. A(l):A(s) was negatively correlated with basal area (r2 = 0.93). We hypothesize that increased A(l):A(s) is a homeostatic response to increased water availability that maximizes water-use efficiency and whole-tree carbon uptake. Elevated A(l):A(s) of trees at low basal areas was associated with greater

  11. Comparison of different real time VOC measurement techniques in a ponderosa pine forest

    Science.gov (United States)

    Kaser, L.; Karl, T.; Schnitzhofer, R.; Graus, M.; Herdlinger-Blatt, I. S.; DiGangi, J. P.; Sive, B.; Turnipseed, A.; Hornbrook, R. S.; Zheng, W.; Flocke, F. M.; Guenther, A.; Keutsch, F. N.; Apel, E.; Hansel, A.

    2013-03-01

    Volatile organic compound (VOC) mixing ratios measured by five independent instruments are compared at a forested site dominated by ponderosa pine (Pinus Ponderosa) during the BEACHON-ROCS field study in summer 2010. The instruments included a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS), a Proton Transfer Reaction Quadrupole Mass Spectrometer (PTR-MS), a Fast Online Gas-Chromatograph coupled to a Mass Spectrometer (GC/MS; TOGA), a Thermal Dissociation Chemical Ionization Mass Spectrometer (PAN-CIMS) and a Fiber Laser-Induced Fluorescence Instrument (FILIF). The species discussed in this comparison include the most important biogenic VOCs and a selected suite of oxygenated VOCs that are thought to dominate the VOC reactivity at this particular site as well as typical anthropogenic VOCs that showed low mixing ratios at this site. Good agreement was observed for methanol, the sum of the oxygenated hemiterpene 2-methyl-3-buten-2-ol (MBO) and the hemiterpene isoprene, acetaldehyde, the sum of acetone and propanal, benzene and the sum of methyl ethyl ketone (MEK) and butanal. Measurements of the above VOCs conducted by different instruments agree within 20%. The ability to differentiate the presence of toluene and cymene by PTR-TOF-MS is tested based on a comparison with GC-MS measurements, suggesting a study-average relative contribution of 74% for toluene and 26% for cymene. Similarly, 2-hydroxy-2-methylpropanal (HMPR) is found to interfere with the sum of methyl vinyl ketone and methacrolein (MVK + MAC) using PTR-(TOF)-MS at this site. A study-average relative contribution of 85% for MVK + MAC and 15% for HMPR was determined. The sum of monoterpenes measured by PTR-MS and PTR-TOF-MS was generally 20-25% higher than the sum of speciated monoterpenes measured by TOGA, which included α-pinene, β-pinene, camphene, carene, myrcene, limonene, cineole as well as other terpenes. However, this difference is consistent throughout the study, and

  12. Soil responses to management, increased precipitation, and added nitrogen in ponderosa pine forests.

    Science.gov (United States)

    Hungate, Bruce A; Hart, Stephen C; Selmants, Paul C; Boyle, Sarah I; Gehring, Catherine A

    2007-07-01

    Forest management, climatic change, and atmospheric N deposition can affect soil biogeochemistry, but their combined effects are not well understood. We examined the effects of water and N amendments and forest thinning and burning on soil N pools and fluxes in ponderosa pine forests near Flagstaff, Arizona (USA). Using a 15N-depleted fertilizer, we also documented the distribution of added N into soil N pools. Because thinning and burning can increase soil water content and N availability, we hypothesized that these changes would alleviate water and N limitation of soil processes, causing smaller responses to added N and water in the restored stand. We found little support for this hypothesis. Responses of fine root biomass, potential net N mineralization, and the soil microbial N to water and N amendments were mostly unaffected by stand management. Most of the soil processes we examined were limited by N and water, and the increased N and soil water availability caused by forest restoration was insufficient to alleviate these limitations. For example, N addition caused a larger increase in potential net nitrification in the restored stand, and at a given level of soil N availability, N addition had a larger effect on soil microbial N in the restored stand. Possibly, forest restoration increased the availability of some other limiting resource, amplifying responses to added N and water. Tracer N recoveries in roots and in the forest floor were lower in the restored stand. Natural abundance delta15N of labile soil N pools were higher in the restored stand, consistent with a more open N cycle. We conclude that thinning and burning open up the N cycle, at least in the short-term, and that these changes are amplified by enhanced precipitation and N additions. Our results suggest that thinning and burning in ponderosa pine forests will not increase their resistance to changes in soil N dynamics resulting from increased atmospheric N deposition or increased

  13. Pelletized ponderosa pine bark for adsorption of toxic heavy metals from water

    Directory of Open Access Journals (Sweden)

    Tshabalala, M. A.

    2007-02-01

    Full Text Available Bark flour from ponderosa pine (Pinus ponderosa was consolidated into pellets using citric acid as cross-linking agent. The pellets were evaluated for removal of toxic heavy metals from synthetic aqueous solutions. When soaked in water, pellets did not leach tannins, and they showed high adsorption capacity for Cu(II, Zn(II, Cd(II, and Ni(II under both equilibrium and dynamic adsorption conditions. The experimental data for Cd(II and Zn(II showed a better fit to the Langmuir than to the Freundlich isotherm. The Cu(II data best fit the Freundlich isotherm, and the Ni(II data fitted both Freundlich and Langmuir isotherms equally. According to the Freundlich constant KF, adsorption capacity of pelletized bark for the metal ions in aqueous solution, pH 5.1 ± 0.2, followed the order Cd(II > Cu(II > Zn(II >> Ni(II; according to the Langmuir constant b, adsorption affinity followed the order Cd(II >> Cu(II ≈ Zn(II >> Ni(II. Although data from dynamic column adsorption experiments did not show a good fit to the Thomas kinetic adsorption model, estimates of sorption affinity series of the metal ions on pelletized bark derived from this model were not consistent with the series derived from the Langmuir or Freundlich isotherms and followed the order Cu(II > Zn(II ≈ Cd(II > Ni(II. According to the Thomas kinetic model, the theoretical maximum amounts of metal that can be sorbed on the pelletized bark in a column at influent concentration of ≈10 mg/L and flow rate = 5 mL/min were estimated to be 57, 53, 50, and 27 mg/g for copper, zinc, cadmium, and nickel, respectively. This study demonstrated the potential for converting low-cost bark residues to value-added sorbents using starting materials and chemicals derived from renewable resources. These sorbents can be applied in the removal of toxic heavy metals from waste streams with heavy metal ion concentrations of up to 100 mg/L in the case of Cu(II.

  14. Comparison of different real time VOC measurement techniques in a ponderosa pine forest

    Directory of Open Access Journals (Sweden)

    L. Kaser

    2012-10-01

    Full Text Available Volatile organic compound (VOC mixing ratios measured by five independent instruments are compared at a forested site dominated by ponderosa pine (Pinus Ponderosa during the BEACHON-ROCS field study in summer 2010. The instruments included a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS, a Proton Transfer Reaction Quadrupole Mass Spectrometer (PTR-MS, a Fast Online Gas-Chromatograph coupled to a Mass Spectrometer (GC/MS; TOGA, a Thermal Dissociation Chemical Ionization Mass Spectrometer (PAN-CIMS and a Fiber Laser-Induced Fluorescence Instrument (FILIF. The species discussed in this comparison include the most important biogenic VOCs and a selected suite of oxygenated VOCs that are thought to dominate the VOC reactivity at this particular site as well as typical anthropogenic VOCs that showed low mixing ratios at this site. Good agreement was observed for methanol, the sum of the oxygenated hemiterpene 2-methyl-3-buten-2-ol (MBO and the hemiterpene isoprene, acetaldehyde, the sum of acetone and propanal, benzene and the sum of methyl ethyl ketone (MEK and butanal. Measurements of the above VOCs conducted by different instruments agree within 20%. The ability to differentiate the presence of toluene and cymene by PTR-TOF-MS is tested based on a comparison with GC-MS measurements, suggesting a study-average relative contribution of 74% for toluene and 26% for cymene. Similarly, 2-hydroxy-2-methylpropanal (HMPR is found to interfere with the sum of methyl vinyl ketone and methacrolein (MVK+MAC using PTR-(TOF-MS at this site. A study-average relative contribution of 85% for MVK+MAC and 15% for HMPR was determined. The sum of monoterpenes measured by PTR-MS and PTR-TOF-MS was generally 20–25% higher than the sum of speciated monoterpenes measured by TOGA, which included α-pinene, β-pinene, camphene, carene, myrcene, limonene, cineole as well as other terpenes. However, this difference is consistent throughout the

  15. Comparison of different real time VOC measurement techniques in a ponderosa pine forest

    Directory of Open Access Journals (Sweden)

    L. Kaser

    2013-03-01

    Full Text Available Volatile organic compound (VOC mixing ratios measured by five independent instruments are compared at a forested site dominated by ponderosa pine (Pinus Ponderosa during the BEACHON-ROCS field study in summer 2010. The instruments included a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS, a Proton Transfer Reaction Quadrupole Mass Spectrometer (PTR-MS, a Fast Online Gas-Chromatograph coupled to a Mass Spectrometer (GC/MS; TOGA, a Thermal Dissociation Chemical Ionization Mass Spectrometer (PAN-CIMS and a Fiber Laser-Induced Fluorescence Instrument (FILIF. The species discussed in this comparison include the most important biogenic VOCs and a selected suite of oxygenated VOCs that are thought to dominate the VOC reactivity at this particular site as well as typical anthropogenic VOCs that showed low mixing ratios at this site. Good agreement was observed for methanol, the sum of the oxygenated hemiterpene 2-methyl-3-buten-2-ol (MBO and the hemiterpene isoprene, acetaldehyde, the sum of acetone and propanal, benzene and the sum of methyl ethyl ketone (MEK and butanal. Measurements of the above VOCs conducted by different instruments agree within 20%. The ability to differentiate the presence of toluene and cymene by PTR-TOF-MS is tested based on a comparison with GC-MS measurements, suggesting a study-average relative contribution of 74% for toluene and 26% for cymene. Similarly, 2-hydroxy-2-methylpropanal (HMPR is found to interfere with the sum of methyl vinyl ketone and methacrolein (MVK + MAC using PTR-(TOF-MS at this site. A study-average relative contribution of 85% for MVK + MAC and 15% for HMPR was determined. The sum of monoterpenes measured by PTR-MS and PTR-TOF-MS was generally 20–25% higher than the sum of speciated monoterpenes measured by TOGA, which included α-pinene, β-pinene, camphene, carene, myrcene, limonene, cineole as well as other terpenes. However, this difference is consistent throughout the study

  16. Net Ecosystem Fluxes of Hydrocarbons from a Ponderosa Pine Forest in Colorado

    Science.gov (United States)

    Rhew, R. C.; Turnipseed, A. A.; Ortega, J. V.; Smith, J. N.; Guenther, A. B.; Shen, S.; Martinez, L.; Koss, A.; Warneke, C.; De Gouw, J. A.; Deventer, M. J.

    2015-12-01

    Light (C2-C4) alkenes, light alkanes and isoprene (C5H8) are non-methane hydrocarbons that play important roles in the photochemical production of tropospheric ozone and in the formation of secondary organic aerosols. Natural terrestrial fluxes of the light hydrocarbons are poorly characterized, with global emission estimates based on limited field measurements. In 2014, net fluxes of these compounds were measured at the Manitou Experimental Forest Observatory, a semi-arid ponderosa pine forest in the Colorado Rocky Mountains and site of the prior BEACHON campaigns. Three field intensives were conducted between June 17 and August 10, 2014. Net ecosystem flux measurements utilized a relaxed eddy accumulation system coupled to an automated gas chromatograph. Summertime average emissions of ethene and propene were up to 90% larger than those observed from a temperate deciduous forest. Ethene and propene fluxes were also correlated to each other, similar to the deciduous forest study. Emissions of isoprene were small, as expected for a coniferous forest, and these fluxes were not correlated with either ethene or propene. Unexpected emissions of light alkanes were also observed, and these showed a distinct diurnal cycle. Understory flux measurements allowed for the partitioning of fluxes between the surface and the canopy. Full results from the three field intensives will be compared with environmental variables in order to parameterize the fluxes for use in modeling emissions.

  17. Contributions of biogenic volatile organic compounds to net ecosystem carbon flux in a ponderosa pine plantation

    Science.gov (United States)

    Bouvier-Brown, Nicole C.; Schade, Gunnar W.; Misson, Laurent; Lee, Anita; McKay, Megan; Goldstein, Allen H.

    2012-12-01

    When assessing net ecosystem exchange (NEE) and net ecosystem carbon balance (NECB), respiration is generally assumed to be the only significant loss of carbon to the atmosphere. However, carbon is also emitted from ecosystems in the form of biogenic volatile organic compounds (BVOCs). Here we consider the magnitude of systematic difference caused by omitting this additional carbon loss from the net ecosystem carbon balance, as compared to the NEE term, of the ponderosa pine plantation at Blodgett Forest. We find that 9.4 (range 6.2-12.5) g C m-2 yr-1 were emitted from this ecosystem as BVOCs. This is 4.0 (2.0-7.9) % of annual NEE, and neglecting this additional loss of carbon causes an overestimation of carbon storage for this rapidly growing commercial forest plantation. For ecosystems that are not storing carbon as rapidly, where photosynthesis and respiration are more closely balanced, ignoring BVOC emission may cause a larger error in the estimation of NECB.

  18. Temperature and light acclimation of photosynthetic capacity in seedlings and mature trees of Pinus ponderosa

    Directory of Open Access Journals (Sweden)

    Bahram Momen

    2014-03-01

    Full Text Available A preliminary step to understand the impact of possible rise in temperature on carbon dynamics of forests is to examine the temperature elasticity of key processes involved in carbon fixation in forest trees. For seedling and mature ponderosa pines of three genotypes, we used a response-surface methodology and ANOVA to evaluate changes in maximum net photosynthesis (An max, and corresponding light (LAn max and temperature (TAn max to diurnal and seasonal changes in ambient temperature during summer and autumn. As seasonal ambient temperature decreased: (1 An max did not change in seedlings or mature trees, (2 LAn max did not change in mature trees, but it decreased for current-yr foliage of seedlings from 964 to 872 µmol photons m-2 s-1, and (3 TAn max did not change in seedlings but it decreased in mature trees for both current- and one-yr-old foliage, from 26.8 to 22.2, and 24.6 to 21.7 C, respectively.

  19. Primer registro de Naupactus ruizi (Coleoptera: Curculionoidea asociado con Pinus ponderosa (Gymnospermae: Pinaceae en Patagonia

    Directory of Open Access Journals (Sweden)

    Cecilia A. GOMEZ

    2006-01-01

    Full Text Available Naupactus ruizi (Brèthes es un gorgojo de rostro corto, distribuido en la Argentina y Chile, que habita en ambientes áridos asociado con vegetación xerofítica y alcanza el rango más austral entre los miembros de la tribu Naupactini. Un relevamiento de insectos y de patógenos como plagas potenciales, realizado durante el 2005 en plantaciones de Pinus spp. en la Patagonia andina argentina, resultó en el hallazgo de adultos de N. ruizi que se alimentaban de acículas de Pinus ponderosa Dougl. ex Laws. Este hallazgo es sorprendente dado que las especies de Naupactini, consumen casi exclusivamente angiospermas. Interpretamos que el cambio de huésped, habría ocurrido como consecuencia de una colonización reciente favorecida por la amplia distribución geográfica del gorgojo y su capacidad para sobrevivir en hábitats marginales, donde probablemente las plantas nativas son escasas y el nuevo huésped presenta una gran abundancia local.

  20. Expression, purification and characterization of an endoglucanase from Serratia proteamaculans CDBB-1961, isolated from the gut of Dendroctonus adjunctus (Coleoptera: Scolytinae).

    Science.gov (United States)

    Cano-Ramírez, Claudia; Santiago-Hernández, Alejandro; Rivera-Orduña, Flor Nohemí; García-Huante, Yolanda; Zúñiga, Gerardo; Hidalgo-Lara, María Eugenia

    2016-12-01

    Serratia proteamaculans CDBB-1961, a gut symbiont from the roundheaded pine beetle Dendroctonus adjunctus, displayed strong cellulolytic activity on agar-plates with carboxymethyl cellulose (CMC) as carbon source. Automatic genome annotation of S. proteamaculans made possible the identification of a single endoglucanase encoding gene, designated spr cel8A. The predicted protein, named Spr Cel8A shows high similarity (59-94 %) to endo-1,4-β-D-glucanases (EC 3.2.1.4) from the glycoside hydrolase family 8 (GH8). The gene spr cel8A has an ORF of 1113 bp, encoding a 371 amino acid residue protein (41.2 kDa) with a signal peptide of 23 amino acid residues. Expression of the gene spr cel8A in Escherichia coli yields a mature recombinant endoglucanase 39 kDa. Cel8A displayed optimal activity at pH 7.0 and 40 °C, with a specific activity of 0.85 U/mg. The enzyme was stable at pH from 4 to 8.5, retaining nearly 40-80 % of its original activity, and exhibited a half-life of 8 days at 40 °C. The K m and V max values for Spr Cel8A were 6.87 mg/ml and 3.5 μmol/min/mg of protein, respectively, using CMC as substrate. The final principle products of Spr Cel8A-mediated hydrolysis of CMC were cellobiose, cello oligosaccharides and a small amount of glucose, suggesting that Spr Cel8A is an endo-β-1,4-glucanase manifesting exo-activity. This is the first report regarding the functional biochemical and molecular characterization of an endoglucanase from S. proteamaculans, found in the gut-associated bacteria community of Dendroctonus bark beetles. These results contribute to improved understanding of the functional role played by this bacterium as a symbiont of bark beetles.

  1. Effects of climate variability and accelerated forest thinning on watershed-scale runoff in southwestern USA ponderosa pine forests.

    Science.gov (United States)

    Robles, Marcos D; Marshall, Robert M; O'Donnell, Frances; Smith, Edward B; Haney, Jeanmarie A; Gori, David F

    2014-01-01

    The recent mortality of up to 20% of forests and woodlands in the southwestern United States, along with declining stream flows and projected future water shortages, heightens the need to understand how management practices can enhance forest resilience and functioning under unprecedented scales of drought and wildfire. To address this challenge, a combination of mechanical thinning and fire treatments are planned for 238,000 hectares (588,000 acres) of ponderosa pine (Pinus ponderosa) forests across central Arizona, USA. Mechanical thinning can increase runoff at fine scales, as well as reduce fire risk and tree water stress during drought, but the effects of this practice have not been studied at scales commensurate with recent forest disturbances or under a highly variable climate. Modifying a historical runoff model, we constructed scenarios to estimate increases in runoff from thinning ponderosa pine at the landscape and watershed scales based on driving variables: pace, extent and intensity of forest treatments and variability in winter precipitation. We found that runoff on thinned forests was about 20% greater than unthinned forests, regardless of whether treatments occurred in a drought or pluvial period. The magnitude of this increase is similar to observed declines in snowpack for the region, suggesting that accelerated thinning may lessen runoff losses due to warming effects. Gains in runoff were temporary (six years after treatment) and modest when compared to mean annual runoff from the study watersheds (0-3%). Nonetheless gains observed during drought periods could play a role in augmenting river flows on a seasonal basis, improving conditions for water-dependent natural resources, as well as benefit water supplies for downstream communities. Results of this study and others suggest that accelerated forest thinning at large scales could improve the water balance and resilience of forests and sustain the ecosystem services they provide.

  2. Can a fake fir tell the truth about Swiss needle cast? (paper)

    Science.gov (United States)

    A key question in dendrochronology to reconstruct forest disturbance history is how to distinguish between the effects of Swiss needle cast (SNC) and other forest disturbance agents (e.g., Arceuthobium spp., Armillaria, Phaseolus schweinitzii, Dendroctonus ponderosae, Dendroctonu...

  3. Can a fake fir tell the truth about Swiss needle cast? (paper)

    Science.gov (United States)

    A key question in dendrochronology to reconstruct forest disturbance history is how to distinguish between the effects of Swiss needle cast (SNC) and other forest disturbance agents (e.g., Arceuthobium spp., Armillaria, Phaseolus schweinitzii, Dendroctonus ponderosae, Dendroctonu...

  4. Overstory Tree Mortality in Ponderosa Pine and Spruce-Fir Ecosystems Following a Drought in Northern New Mexico

    OpenAIRE

    Brian P. Oswald; Sean C. Dugan; Balice, Randy G.; Daniel R. Unger

    2016-01-01

    Drought-caused tree dieback is an issue around the world as climates change and many areas become dryer and hotter. A drought from 1998–2004 resulted in a significant tree dieback event in many of the wooded areas in portions of the Jemez Mountains and the adjacent Pajarito Plateau in northern New Mexico. The objectives of this study were to evaluate and quantify the differences in tree mortality before and after a recent drought in ponderosa pine and spruce-fir ecosystems, and to assess the ...

  5. Mattesia weiseri sp. nov., a new neogregarine (Apicomplexa: Lipotrophidae) pathogen of the great spruce bark beetle, Dendroctonus micans (Coleoptera: Curculionidae, Scolytinae).

    Science.gov (United States)

    Yaman, Mustafa; Radek, Renate

    2015-08-01

    A new neogregarine pathogen of the great spruce bark beetle, Dendroctonus micans (Coleoptera: Curculionidae, Scolytinae), is described based on light microscopy and ultrastructural characteristics. The pathogen infects the fat body and the hemolymph of the beetle. The infection was nonsynchronous so that different developmental stages could be observed simultaneously in the hemolymph. All life stages from sporozoite to oocyst of the pathogen including micronuclear and macronuclear merozoites were detected. The sporozoites measured about 8.7 × 1.9 μm and trophozoites, 11.9 × 3.3 μm. Micronuclear merozoites seen in the hemolymph were motile, elongate, slightly broader at the anterior pole, and measured 18.4 × 2.0 μm. Macronuclear merozoites had a size of ca. 16.4 × 2.3 μm. Gametogamy results in the formation of two paired oocysts within a gametocyst. The lemon-shaped oocyst measured 10.9 × 6.1 μm and had a very thick wall (375-450 nm). All morphological and ultrastructural characteristics of the life cycle stages indicate that the described neogregarine in D. micans is clearly different from known Mattesia species infecting bark beetles, and from any other described Mattesia spp. Therefore, we create a new species, Mattesia weiseri sp. nov.

  6. Contributions by Host Trees and Insect Activity to Bacterial Communities in Dendroctonus valens (Coleoptera: Curculionidae) Galleries, and Their High Overlap With Other Microbial Assemblages of Bark Beetles.

    Science.gov (United States)

    Mason, Charles J; Hanshew, Alissa S; Raffa, Kenneth F

    2016-04-01

    Bark beetles are associated with a diversity of symbiotic microbiota that can mediate interactions with their host plants. Dendroctonus valens LeConte is a widely distributed bark beetle in North and Central America, and initiates solitary attacks on several species of Pinus in the Great Lakes region. In this study, we aimed to further characterize the bacterial community associated with D. valens feeding galleries using next-generation sequencing, and the possible contributions of both tree-resident and insect-associated bacteria to these consortia. We found that D. valens galleries harbor a diversity of microbial associates. Many of these associates were classified into a few taxonomic groups, of which Gammaproteobacteria were the most abundant class. Of the Gammaproteobacteria detected, many formed clades with 16S-rRNA sequences of bacteria previously associated with D. valens Many of the bacteria sequences detected in the galleries were similar to bacteria that function in detoxification, kairomone metabolism, and nitrogen fixation and cycling. The abundance of bacteria in galleries were 7× and 44× higher than in the surrounding uninfested tissues, and that were not attacked by D. valens, respectively. This suggests that the bacteria present in beetle galleries are largely introduced by D. valens and proliferate in this environment. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Isolation and expression of cytochrome P450 genes in the antennae and gut of pine beetle Dendroctonus rhizophagus (Curculionidae: Scolytinae) following exposure to host monoterpenes.

    Science.gov (United States)

    Cano-Ramírez, Claudia; López, María Fernanda; Cesar-Ayala, Ana K; Pineda-Martínez, Verónica; Sullivan, Brian T; Zúñiga, Gerardo

    2013-05-10

    Bark beetles oxidize the defensive monoterpenes of their host trees both to detoxify them and convert them into components of their pheromone system. This oxidation is catalyzed by cytochrome P450 enzymes and occurs in different tissues of the insect, including the gut (i.e., the site where the beetle's pheromones are produced and accumulated) and the antennae (i.e., the olfactory organs used for perception of airborne defensive monoterpenes as well as other host-associated compounds and pheromones). We identified ten new CYP genes in the pine beetle Dendroctonus rhizophagus in either antennae or gut tissue after stimulation with the vapors of major host monoterpenes α-pinene, β-pinene and 3-carene. Five genes belong to the CYP4 family, four to the CYP6 family and one to the CYP9 family. Differential expression of almost all of the CYP genes was observed between sexes, and within these significant differences among time, stimuli, anatomical region, and their interactions were found upon exposure to host monoterpenes. Increased expression of cytochrome P450 genes suggests that they play a role in the detoxification of monoterpenes released by this insect's host trees. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Two CYP4 genes of the Chinese white pine beetle, Dendroctonus armandi (Curculionidae: Scolytinae), and their transcript levels under different development stages and treatments.

    Science.gov (United States)

    Dai, L; Wang, C; Zhang, X; Yu, J; Zhang, R; Chen, H

    2014-10-01

    Bark beetles oxidize the defensive monoterpenes of their host trees both to detoxify them and to convert them into components of their pheromone system. This oxidation is catalysed by cytochrome P450 (CYP) enzymes and occurs in different stages of the insect. We identified two new CYP4 genes in the Chinese white pine beetle (Dendroctonus armandi), and carried out bioinformatic analysis one the full-length nucleic acid sequences and deduced amino acid sequences. Differential expression of the CYP4 genes was observed between sexes, and within these significant differences amongst development stages, fed on phloem of Pinus armandi and exposed to stimuli((±)- α-pinene, (R)-(+)- α-pinene, (S)-(-)-α-pinene, (S)-(-)-β-pinene and (+)-3-carene) at 8 and 24 h, and their interactions were found upon exposure to host monoterpenes. Increased expression of CYP4 genes suggested that they play a role in the detoxification of monoterpenes released by the host trees. The differential transcript accumulation patterns of these bark beetle CYP4 genes provides insight into the ecological interactions of D. armandi with its host pine. © 2014 The Royal Entomological Society.

  9. Characterisation of GST genes from the Chinese white pine beetle Dendroctonus armandi (Curculionidae: Scolytinae) and their response to host chemical defence.

    Science.gov (United States)

    Dai, Lulu; Ma, Junning; Ma, Mingyuan; Zhang, Haoqiang; Shi, Qi; Zhang, Ranran; Chen, Hui

    2016-04-01

    Bark beetles rely on their detoxifying enzymes to resist the defensive terpenoids of host trees. Glutathione S-transferases (GSTs) conjugate xenobiotic compounds with a glutathione moiety (GSH) and often work in tandem with cytochromes P450 or other enzymes that aid in the detoxification, sequestration or excretion of toxic compounds. We identified nine new GST genes in the Chinese white pine beetle (Dendroctonus armandi) and carried out a bioinformatics analysis on the deduced full-length amino acid sequences. These genes belong to four different classes (epsilon, sigma, omega and theta). Differential transcript levels of each class of GST genes were observed between sexes, and, within these levels, significant differences were found among the different adult substages that were fed phloem of Pinus armandi and exposed to six stimuli [(±)-α-pinene, (-)-α-pinene, (-)-β-pinene, (+)-3-carene, (±)-limonene and turpentine] at 8 and 24 h. The increased transcription levels of GST genes suggested that they have some relationship with the detoxification of terpenoids that are released by host trees. The mediating oxidative stress that is caused by monoterpene might be the main role of the bark beetle GSTs. © 2015 Society of Chemical Industry.

  10. Cytochrome P450s from the Chinese white pine beetle, Dendroctonus armandi (Curculionidae: Scolytinae): Expression profiles of different stages and responses to host allelochemicals.

    Science.gov (United States)

    Dai, Lulu; Ma, Mingyuan; Wang, Chunyan; Shi, Qi; Zhang, Ranran; Chen, Hui

    2015-10-01

    Bark beetles oxidize the defensive allelochemicals from their host trees to both detoxify and convert these materials into components of their pheromone system. The ability of this insect to adapt to its chemical environment might be explained by the action of major detoxification enzymes such as cytochrome P450s (or CYPs). Sixty-four sequences coding for P450s were identified, and most of the transcripts were found to be expressed in the larvae, pupae and adults of Dendroctonus armandi. To gain information on how these genes help D. armandi overcome the host defense, differential transcript levels of the CYP genes were observed between sexes and within the sexes. Significant differences were observed among developmental stages, in feeding on the phloem of Pinus armandi and in exposure to stimuli ((±)-α-pinene, (S)-(-)-α-pinene, (S)-(-)-β-pinene, (+)-3-carene, (±)-limonene and turpentine oil) for 8 h. We investigated the effect of sex and generations on the survivorship of individual D. armandi that were exposed to host volatiles at concentrations comparable to constitutive and induced levels of defense using fumigant exposure to understand the ability of the beetles to tolerate host defensive chemicals. The differential transcript accumulation patterns of CYP genes of these bark beetle provided insight into the ecological interactions of D. armandi with its host pine. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Genetic heterogeneity in a cyclical forest pest, the southern pine beetle, Dendroctonus frontalis, is differentiated into east and west groups in the southeastern United States.

    Science.gov (United States)

    Schrey, Natalie M; Schrey, Aaron W; Heist, Edward J; Reeve, John D

    2011-01-01

    The southern pine beetle, Dendroctonus frontalis Zimmerman (Coleoptera: Curculionidae) is an economically important pest species throughout the southeastern United States, Arizona, Mexico, and Central America. Previous research identified population structure among widely distant locations, yet failed to detect population structure among national forests in the state of Mississippi. This study uses microsatellite variation throughout the southeastern United States to compare the southern pine beetle's pattern of population structure to phylogeographic patterns in the region, and to provide information about dispersal. Bayesian clustering identified east and west genetic groups spanning multiple states. The east group had lower heterozygosity, possibly indicating greater habitat fragmentation or a more recent colonization. Significant genetic differentiation (θ(ST) = 0.01, p < 0.0001) followed an isolation-by-distance pattern (r = 0.39, p < 0.001) among samples, and a hierarchical AMOVA indicated slightly more differentiation occurred between multi-state groups. The observed population structure matches a previously identified phylogeographic pattern, division of groups along the Appalachian Mountain/Apalachicola River axis. Our results indicate that the species likely occurs as a large, stable metapopulation with considerable gene flow among subpopulations. Also, the relatively low magnitude of genetic differentiation among samples suggests that southern pine beetles may respond similarly to management across their range.

  12. 陕西红脂大小蠹天敌种类调查%The investigation of natural enemies of Dendroctonus valens in Shaanxi

    Institute of Scientific and Technical Information of China (English)

    王培新; 贺虹; 李健康; 邢建宏; 李孟楼

    2007-01-01

    对陕西红脂大小蠹Dendroctonus valens LeConte危害区的天敌种类调查表明,寄生于红脂大小蠹的病原真菌共有5种,其中幼虫期有头孢霉Cephalosporium sp.、球孢白僵菌Beauveria bassiana和拟卵孢霉Ovulariopsis sp.,成虫期有球孢白僵菌Beauveria bassiana、枝顶孢霉Acremonium sp.、头孢霉Cephalosporium sp.、木霉Trichoderma sp.4种,其中以球孢白僵菌和枝顶孢霉Acremonium sp.的致病能力最为显著.捕食性天敌昆虫主要有西岳蛇蛉Agulla xiyue Yang et Chou、日本弓背蚁Camponotus japionicus Mayr、中华红林蚁Formica sinensis Wheeler、蚁形郭公甲Thanasimus formicarius(L.)及纤细阎甲Platysoma attenuata(LeConte),它们对红脂大小蠹均有较明显的控制作用.寄生性天敌主要有1种寄生蝇和1种茧蜂.

  13. Study on the Biological Characteristic of Dendroctonus valens in Zezhou of Shanxi%泽州县红脂大小蠹生物学特性研究

    Institute of Scientific and Technical Information of China (English)

    李东霞

    2009-01-01

    ;红脂大小蠢(Dendroctonus valens)是我国重要的外来入侵生物,属国家检疫性害虫之一.红脂大小蠢在山西省泽州县分布于伊候山林场、巴公镇、大阳镇,寄主植物有油松、白皮松、华山松.该虫在泽州县1 a发生1代,以成虫和幼虫以及少量的蛹在树干基部或根部的皮层内越冬;采取性诱、化学防治、伐除虫害木、检疫、生物防治、营林等技术进行了防治,防治效果达80%以上,虫株率可控制在1‰以下.

  14. A Preliminary Study of the Biological Character of Dendroctonus armandi%华山松大小蠹生物学特性初步研究

    Institute of Scientific and Technical Information of China (English)

    王兴旺; 张紫晋; 杨伟; 杨春平; 李峰

    2014-01-01

    通过林间和室内观察相结合的方法,研究了四川省南江县华山松大小蠢Dendroctonus armandi的生活史和生活习性.试验结果表明,华山松大小蠹在南江县1 a发生1代或2a发生3代,主要以幼虫在树干韧皮部越冬,极少数以成虫和卵越冬.越冬幼虫化蛹始见于3月下旬,4月~5月为化蛹盛期,成虫于4月中下旬开始扬飞,5月~6月为盛期.成虫产卵期始于4月下旬,7月新一代成虫开始出孔扬飞,部分幼虫直接进入越冬阶段.

  15. Harm and Control of the Dendroctonus valens in Malan Forestry Farm%马栏林场红脂大小蠹危害与防治

    Institute of Scientific and Technical Information of China (English)

    张文龙; 刘高潮

    2014-01-01

    采用定点观测和标准样地调查方法,研究了马栏林区红脂大小蠢(Dendroctonus valens LeConte)生物学特性和危害规律.红脂大小蠢在子午岭南段的马栏林区1a发生1代,以成虫越冬.主要为害胸径10~30 cm的油松,海拔1 300~1 600 m油松林被害严重,林地不同部位之间受害程度沟谷底部、山脊>林缘>林内;山顶>半阳坡>阴坡.采用树干塑料密封薄膜磷化铝熏蒸、树干注射40%氧化乐果乳油、40%敌敌畏乳油都可达到85%以上防治效果.

  16. Distribution of black carbon in Ponderosa pine litter and soils following the High Park wildfire

    Science.gov (United States)

    Boot, C. M.; Haddix, M.; Paustian, K.; Cotrufo, M. F.

    2014-12-01

    Black carbon (BC), the heterogeneous product of burned biomass, is a critical component in the global carbon cycle, yet timescales and mechanisms for incorporation into the soil profile are not well understood. The High Park Fire, which took place in northwestern Colorado in the summer of 2012, provided an opportunity to study the effects of both fire intenstiy and geomorphology on properties of carbon (C), nitrogen (N), and BC in the Cache La Poudre River drainage. We sampled montane Ponderosa pine litter, 0-5 cm soils, and 5-15 cm soils four months post-fire in order to examine the effects of slope and burn intensity on %C, C stocks, %N and black carbon (g kg-1 C, and g m-2). We developed and implemented the benzene polycarboxylic acid (BPCA) method for quantifying BC. With regard to slope, we found that steeper slopes had higher C : N than shallow slopes, but that there was no difference in black carbon content or stocks. BC content was greatest in the litter in burned sites (19 g kg-1 C), while BC stocks were greatest in the 5-15 cm subsurface soils (23 g m-2). At the time of sampling, none of the BC deposited on the land surface post-fire had been incorporated into to either the 0-5 cm or 5-15 cm soil layers. The ratio of B5CA : B6CA (less condensed to more condensed BC) indicated there was significantly more older, more processed BC at depth. Total BC soil stocks were relatively low compared to other fire-prone grassland and boreal forest systems, indicating most of the BC produced in this system is likely transported off the surface through erosion events. Future work examining mechanisms for BC transport will be required for understanding the role BC plays in the global carbon cycle.

  17. Eddy covariance methane measurements at a Ponderosa pine plantation in California

    Directory of Open Access Journals (Sweden)

    T. Röckmann

    2009-11-01

    Full Text Available Long term methane flux measurements have been mostly performed with plant or soil enclosure techniques on specific components of an ecosystem. New fast response methane analyzers make it possible to use the eddy covariance (EC technique instead. The EC technique is advantageous because it allows continuous flux measurements integrating over a larger and more representative area including the complete ecosystem, and allows fluxes to be observed as environmental conditions change naturally without disturbance. We deployed the closed-path Fast Methane analyzer (FMA from Los Gatos Research Ltd and demonstrate its performance for EC measurements at a Ponderosa pine plantation at the Blodgett Forest site in central California. The fluctuations of the CH4 concentration measured at 10 Hz appear to be small and their standard deviation is comparable to the magnitude of the signal noise (±5 ppbv. Consequently, the power spectra typically have a white noise signature at the high frequency end (a slope of +1. Nevertheless, in the frequency range important for turbulent exchange, the cospectra of CH4 compare very well with all other scalar cospectra confirming the quality of the FMA measurements are good for the EC technique. We furthermore evaluate the complications of combined open and closed-path measurements when applying the Webb-Pearman-Leuning (WPL corrections (Webb et al., 1980 and the consequences of a phase lag between the water vapor and methane signal inside the closed path system. The results of diurnal variations of CH4 concentrations and fluxes are summarized and compared to the monthly results of process-based model calculations.

  18. Mountain pine beetle selectivity in old-growth ponderosa pine forests, Montana, USA.

    Science.gov (United States)

    Knapp, Paul A; Soulé, Peter T; Maxwell, Justin T

    2013-05-01

    A historically unprecedented mountain pine beetle (MPB) outbreak affected western Montana during the past decade. We examined radial growth rates (AD 1860-2007/8) of co-occurring mature healthy and MPB-infected ponderosa pine trees collected at two sites (Cabin Gulch and Kitchen Gulch) in western Montana and: (1) compared basal area increment (BAI) values within populations and between sites; (2) used carbon isotope analysis to calculate intrinsic water-use efficiency (iWUE) at Cabin Gulch; and (3) compared climate-growth responses using a suite of monthly climatic variables. BAI values within populations and between sites were similar until the last 20-30 years, at which point the visually healthy populations had consistently higher BAI values (22-34%) than the MPB-infected trees. These results suggest that growth rates two-three decades prior to the current outbreak diverged between our selected populations, with the slower-growing trees being more vulnerable to beetle infestation. Both samples from Cabin Gulch experienced upward trends in iWUE, with significant regime shifts toward higher iWUE beginning in 1955-59 for the visually healthy trees and 1960-64 for the MPB-infected trees. Drought tolerance also varied between the two populations with the visually healthy trees having higher growth rates than MPB-infected trees prior to infection during a multi-decadal period of drying summertime conditions. Intrinsic water-use efficiency significantly increased for both populations during the past 150 years, but there were no significant differences between the visually healthy and MPB-infected chronologies.

  19. Development of genetic diversity, differentiation and structure over 500 years in four ponderosa pine populations.

    Science.gov (United States)

    Lesser, M R; Parchman, T L; Jackson, S T

    2013-05-01

    Population history plays an important role in shaping contemporary levels of genetic variation and geographic structure. This is especially true in small, isolated range-margin populations, where effects of inbreeding, genetic drift and gene flow may be more pronounced than in large continuous populations. Effects of landscape fragmentation and isolation distance may have implications for persistence of range-margin populations if they are demographic sinks. We studied four small, disjunct populations of ponderosa pine over a 500-year period. We coupled demographic data obtained through dendroecological methods with microsatellite data to discern how and when contemporary levels of allelic diversity, among and within-population levels of differentiation, and geographic structure, arose. Alleles accumulated rapidly following initial colonization, demonstrating proportionally high levels of gene flow into the populations. At population sizes of approximately 100 individuals, allele accumulation saturated. Levels of genetic differentiation among populations (F(ST) and Jost's D(est)) and diversity within populations (F(IS)) remained stable through time. There was no evidence of geographic genetic structure at any time in the populations' history. Proportionally, high gene flow in the early stages of population growth resulted in rapid accumulation of alleles and quickly created relatively homogenous genetic patterns among populations. Our study demonstrates that contemporary levels of genetic diversity were formed quickly and early in population development. How contemporary genetic diversity accumulates over time is a key facet of understanding population growth and development. This is especially relevant given the extent and speed at which species ranges are predicted to shift in the coming century.

  20. Eddy covariance fluxes of acyl peroxy nitrates (PAN, PPN, and MPAN above a Ponderosa pine forest

    Directory of Open Access Journals (Sweden)

    G. M. Wolfe

    2008-09-01

    Full Text Available During the Biosphere Effects on AeRosols and Photochemistry EXperiment 2007 (BEARPEX-2007, we observed eddy covariance (EC fluxes of speciated acyl peroxy nitrates (APNs, including peroxyacetyl nitrate (PAN, peroxypropionyl nitrate (PPN and peroxymethacryloyl nitrate (MPAN, above a Ponderosa pine forest in the western Sierra Nevada. All APN fluxes are net downward during the day, with a median midday PAN exchange velocity of −0.3 cm s−1; nighttime storage-corrected APN EC fluxes are smaller than daytime fluxes but still downward. Analysis with a standard resistance model shows that loss of PAN to the canopy is not controlled by turbulent or molecular diffusion. Stomatal uptake contributes to 25–50% of the observed downward PAN flux. Vertical gradients in the PAN thermal decomposition (TD rate explain a similar fraction of the flux, suggesting that a significant portion of the PAN flux into the forest results from chemical processes in the canopy. The remaining "unidentified" portion of the net PAN flux (~15% is ascribed to deposition or reactive uptake on non-stomatal surfaces (e.g. leaf cuticles or soil. Shifts in temperature, moisture and ecosystem activity during the summer – fall transition alter the relative contribution of stomatal uptake, non-stomatal uptake and thermochemical gradients to the net PAN flux. Daytime PAN and MPAN exchange velocities are a factor of 3 smaller than those of PPN during the first two weeks of the measurement period, consistent with strong intra-canopy chemical production of PAN and MPAN during this period. The depositional loss of APNs can be 3–21% of the gross gas-phase TD loss depending on temperature. As a source of nitrogen to the biosphere, PAN deposition is approximately 4–19% of that due to dry deposition of nitric acid at this site.

  1. Eddy covariance fluxes of acyl peroxy nitrates (PAN, PPN and MPAN above a Ponderosa pine forest

    Directory of Open Access Journals (Sweden)

    G. M. Wolfe

    2009-01-01

    Full Text Available During the Biosphere Effects on AeRosols and Photochemistry EXperiment 2007 (BEARPEX-2007, we observed eddy covariance (EC fluxes of speciated acyl peroxy nitrates (APNs, including peroxyacetyl nitrate (PAN, peroxypropionyl nitrate (PPN and peroxymethacryloyl nitrate (MPAN, above a Ponderosa pine forest in the western Sierra Nevada. All APN fluxes are net downward during the day, with a median midday PAN exchange velocity of −0.3 cm s−1; nighttime storage-corrected APN EC fluxes are smaller than daytime fluxes but still downward. Analysis with a standard resistance model shows that loss of PAN to the canopy is not controlled by turbulent or molecular diffusion. Stomatal uptake can account for 25 to 50% of the observed downward PAN flux. Vertical gradients in the PAN thermal decomposition (TD rate explain a similar fraction of the flux, suggesting that a significant portion of the PAN flux into the forest results from chemical processes in the canopy. The remaining "unidentified" portion of the net PAN flux (~15% is ascribed to deposition or reactive uptake on non-stomatal surfaces (e.g. leaf cuticles or soil. Shifts in temperature, moisture and ecosystem activity during the summer – fall transition alter the relative contribution of stomatal uptake, non-stomatal uptake and thermochemical gradients to the net PAN flux. Daytime PAN and MPAN exchange velocities are a factor of 3 smaller than those of PPN during the first two weeks of the measurement period, consistent with strong intra-canopy chemical production of PAN and MPAN during this period. Depositional loss of APNs can be 3–21% of the gross gas-phase TD loss depending on temperature. As a source of nitrogen to the biosphere, PAN deposition represents approximately 4–19% of that due to dry deposition of nitric acid at this site.

  2. Short-term ecological consequences of collaborative restoration treatments in ponderosa pine forests of Colorado

    Science.gov (United States)

    Briggs, Jenny S.; Fornwalt, Paula J.; Feinstein, Jonas A.

    2017-01-01

    Ecological restoration treatments are being implemented at an increasing rate in ponderosa pine and other dry conifer forests across the western United States, via the USDA Forest Service’s Collaborative Forest Landscape Restoration (CFLR) program. In this program, collaborative stakeholder groups work with National Forests (NFs) to adaptively implement and monitor ecological restoration treatments intended to offset the effects of many decades of anthropogenic stressors. We initiated a novel study to expand the scope of treatment effectiveness monitoring efforts in one of the first CFLR landscapes, Colorado’s Front Range. We used a Before/After/Control/Impact framework to evaluate the short-term consequences of treatments on numerous ecological properties. We collected pre-treatment and one year post-treatment data on NF and partner agencies’ lands, in 66 plots distributed across seven treatment units and nearby untreated areas. Our results reflected progress toward several treatment objectives: treated areas had lower tree density and basal area, greater openness, no increase in exotic understory plants, no decrease in native understory plants, and no decrease in use by tree squirrels and ungulates. However, some findings suggested the need for adaptive modification of both treatment prescriptions and monitoring protocols: treatments did not promote heterogeneity of stand structure, and monitoring methods may not have been robust enough to detect changes in surface fuels. Our study highlights both the effective aspects of these restoration treatments, and the importance of initiating and continuing collaborative science-based monitoring to improve the outcomes of broad-scale forest restoration efforts.

  3. Masting in ponderosa pine: comparisons of pollen and seed over space and time.

    Science.gov (United States)

    Mooney, Kailen A; Linhart, Yan B; Snyder, Marc A

    2011-03-01

    Many plant species exhibit variable and synchronized reproduction, or masting, but less is known of the spatial scale of synchrony, effects of climate, or differences between patterns of pollen and seed production. We monitored pollen and seed cone production for seven Pinus ponderosa populations (607 trees) separated by up to 28 km and 1,350 m in elevation in Boulder County, Colorado, USA for periods of 4-31 years for a mean per site of 8.7 years for pollen and 12.1 for seed cone production. We also analyzed climate data and a published dataset on 21 years of seed production for an eighth population (Manitou) 100 km away. Individual trees showed high inter-annual variation in reproduction. Synchrony was high within populations, but quickly became asynchronous among populations with a combination of increasing distance and elevational difference. Inter-annual variation in temperature and precipitation had differing influences on seed production for Boulder County and Manitou. We speculate that geographically variable effects of climate on reproduction arise from environmental heterogeneity and population genetic differentiation, which in turn result in localized synchrony. Although individual pines produce pollen and seed, only one-third of the covariation within trees was shared. As compared to seed cones, pollen had lower inter-annual variation at the level of the individual tree and was more synchronous. However, pollen and seed production were similar with respect to inter-annual variation at the population level, spatial scales of synchrony and associations with climate. Our results show that strong masting can occur at a localized scale, and that reproductive patterns can differ between pollen and seed cone production in a hermaphroditic plant.

  4. Distribution of black carbon in Ponderosa pine litter and soils following the High Park wildfire

    Directory of Open Access Journals (Sweden)

    C. M. Boot

    2014-12-01

    Full Text Available Black carbon (BC, the heterogeneous product of burned biomass, is a critical component in the global carbon cycle, yet timescales and mechanisms for incorporation into the soil profile are not well understood. The High Park Fire, which took place in northwestern Colorado in the summer of 2012, provided an opportunity to study the effects of both fire intenstiy and geomorphology on properties of carbon (C, nitrogen (N, and BC in the Cache La Poudre River drainage. We sampled montane Ponderosa pine litter, 0–5 cm soils, and 5–15 cm soils four months post-fire in order to examine the effects of slope and burn intensity on %C, C stocks, %N and black carbon (g kg−1 C, and g m−2. We developed and implemented the benzene polycarboxylic acid (BPCA method for quantifying BC. With regard to slope, we found that steeper slopes had higher C : N than shallow slopes, but that there was no difference in black carbon content or stocks. BC content was greatest in the litter in burned sites (19 g kg−1 C, while BC stocks were greatest in the 5–15 cm subsurface soils (23 g m−2. At the time of sampling, none of the BC deposited on the land surface post-fire had been incorporated into to either the 0–5 cm or 5–15 cm soil layers. The ratio of B5CA : B6CA (less condensed to more condensed BC indicated there was significantly more older, more processed BC at depth. Total BC soil stocks were relatively low compared to other fire-prone grassland and boreal forest systems, indicating most of the BC produced in this system is likely transported off the surface through erosion events. Future work examining mechanisms for BC transport will be required for understanding the role BC plays in the global carbon cycle.

  5. EFFECTS OF CLIMATE VARIABILITY ON THE CARBON DIOXIDE, WATER, AND SENSIBLE HEAT FLUXES ABOVE A PONDEROSA PINE PLANTATION IN THE SIERRA NEVADA, CA. (R826601)

    Science.gov (United States)

    AbstractFluxes of CO2, water vapor, and sensible heat were measured by the eddy covariance method above a young ponderosa pine plantation in the Sierra Nevada Mountains (CA) over two growing seasons (1 June¯10 September 1997 and 1 May&#...

  6. Individual tree diameter increment model for managed even-aged stands of ponderosa pine throughout the western United States using a multilevel linear mixed effects model

    Science.gov (United States)

    Fabian C.C. Uzoh; William W. Oliver

    2008-01-01

    A diameter increment model is developed and evaluated for individual trees of ponderosa pine throughout the species range in the United States using a multilevel linear mixed model. Stochastic variability is broken down among period, locale, plot, tree and within-tree components. Covariates acting at tree and stand level, as breast height diameter, density, site index...

  7. Extreme late-summer drought causes neutral annual carbon balance in southwestern ponderosa pine forests and grasslands

    Science.gov (United States)

    Kolb, Thomas; Dore, Sabina; Montes-Helu, Mario

    2013-03-01

    We assessed the impacts of extreme late-summer drought on carbon balance in a semi-arid forest region in Arizona. To understand drought impacts over extremes of forest cover, we measured net ecosystem production (NEP), gross primary production (GPP), and total ecosystem respiration (TER) with eddy covariance over five years (2006-10) at an undisturbed ponderosa pine (Pinus ponderosa) forest and at a former forest converted to grassland by intense burning. Drought shifted annual NEP from a weak source of carbon to the atmosphere to a neutral carbon balance at the burned site and from a carbon sink to neutral at the undisturbed site. Carbon fluxes were particularly sensitive to drought in August. Drought shifted August NEP at the undisturbed site from sink to source because the reduction of GPP (70%) exceeded the reduction of TER (35%). At the burned site drought shifted August NEP from weak source to neutral because the reduction of TER (40%) exceeded the reduction of GPP (20%). These results show that the lack of forest recovery after burning and the exposure of undisturbed forests to late-summer drought reduce carbon sink strength and illustrate the high vulnerability of forest carbon sink strength in the southwest US to predicted increases in intense burning and precipitation variability.

  8. Short-Term Belowground Responses to Thinning and Burning Treatments in Southwestern Ponderosa Pine Forests of the USA

    Directory of Open Access Journals (Sweden)

    Steven T. Overby

    2016-02-01

    Full Text Available Microbial-mediated decomposition and nutrient mineralization are major drivers of forest productivity. As landscape-scale fuel reduction treatments are being implemented throughout the fire-prone western United States of America, it is important to evaluate operationally how these wildfire mitigation treatments alter belowground processes. We quantified these important belowground components before and after management-applied fuel treatments of thinning alone, thinning combined with prescribed fire, and prescribed fire in ponderosa pine (Pinus ponderosa stands at the Southwest Plateau, Fire and Fire Surrogate site, Arizona. Fuel treatments did not alter pH, total carbon and nitrogen (N concentrations, or base cations of the forest floor (O horizon or mineral soil (0–5 cm during this 2-year study. In situ rates of net N mineralization and nitrification in the surface mineral soil (0–15 cm increased 6 months after thinning with prescribed fire treatments; thinning only resulted in net N immobilization. The rates returned to pre-treatment levels after one year. Based on phospholipid fatty acid composition, microbial communities in treated areas were similar to untreated areas (control in the surface organic horizon and mineral soil (0–5 cm after treatments. Soil potential enzyme activities were not significantly altered by any of the three fuel treatments. Our results suggest that a variety of one-time alternative fuel treatments can reduce fire hazard without degrading soil fertility.

  9. Interactive effects of historical logging and fire exclusion on ponderosa pine forest structure in the northern Rockies.

    Science.gov (United States)

    Naficy, Cameron; Sala, Anna; Keeling, Eric G; Graham, Jon; DeLuca, Thomas H

    2010-10-01

    Increased forest density resulting from decades of fire exclusion is often perceived as the leading cause of historically aberrant, severe, contemporary wildfires and insect outbreaks documented in some fire-prone forests of the western United States. Based on this notion, current U.S. forest policy directs managers to reduce stand density and restore historical conditions in fire-excluded forests to help minimize high-severity disturbances. Historical logging, however, has also caused widespread change in forest vegetation conditions, but its long-term effects on vegetation structure and composition have never been adequately quantified. We document that fire-excluded ponderosa pine forests of the northern Rocky Mountains logged prior to 1960 have much higher average stand density, greater homogeneity of stand structure, more standing dead trees and increased abundance of fire-intolerant trees than paired fire-excluded, unlogged counterparts. Notably, the magnitude of the interactive effect of fire exclusion and historical logging substantially exceeds the effects of fire exclusion alone. These differences suggest that historically logged sites are more prone to severe wildfires and insect outbreaks than unlogged, fire-excluded forests and should be considered a high priority for fuels reduction treatments. Furthermore, we propose that ponderosa pine forests with these distinct management histories likely require distinct restoration approaches. We also highlight potential long-term risks of mechanical stand manipulation in unlogged forests and emphasize the need for a long-term view of fuels management.

  10. Traps and attractants for wood-boring insects in ponderosa pine stands in the Black Hills, South Dakota.

    Science.gov (United States)

    Costello, Sheryl L; Negrón, José F; Jacobi, William R

    2008-04-01

    Recent large-scale wildfires have increased populations of wood-boring insects in the Black Hills of South Dakota. Because little is known about possible impacts of wood-boring insects in the Black Hills, land managers are interested in developing monitoring techniques such as flight trapping with semiochemical baits. Two trap designs and four semiochemical attractants were tested in a recently burned ponderosa pine, Pinus ponderosa Dougl. ex Laws., forest in the Black Hills. Modified panel and funnel traps were tested in combination with the attractants, which included a woodborer standard (ethanol and alpha-pinene), standard plus 3-carene, standard plus ipsenol, and standard plus ipsdienol. We found that funnel traps were equally efficient or more efficient in capturing wood-boring insects than modified panel traps. Trap catches of cerambycids increased when we added the Ips spp. pheromone components (ipsenol or ipsdienol) or the host monoterpene (3-carene) to the woodborer standard. During the summers of 2003 and 2004, 18 cerambycid, 14 buprestid, and five siricid species were collected. One species of cerambycid, Monochamus clamator (LeConte), composed 49 and 40% of the 2003 and 2004 trap catches, respectively. Two other cerambycids, Acanthocinus obliquus (LeConte) and Acmaeops proteus (Kirby), also were frequently collected. Flight trap data indicated that some species were present throughout the summer, whereas others were caught only at the beginning or end of the summer.

  11. Effects of bark beetle attack on canopy fuel flammability and crown fire potential in lodgepole pine and Engelmann spruce forests

    Science.gov (United States)

    Wesley G. Page; Martin E. Alexander; Michael J. Jenkins

    2015-01-01

    Large wildland fires in conifer forests typically involve some degree of crowning, with their initiation and propagation dependent upon several characteristics of the canopy fuels. Recent outbreaks of mountain pine beetle (Dendroctonus ponderosae Hopkins) in lodgepole pine (Pinus contorta Dougl. var. latifolia E ngelm.) forests and spruce beetle (Dendroctonus...

  12. Examining historical and current mixed-severity fire regimes in ponderosa pine and mixed-conifer forests of western North America.

    Science.gov (United States)

    Odion, Dennis C; Hanson, Chad T; Arsenault, André; Baker, William L; Dellasala, Dominick A; Hutto, Richard L; Klenner, Walt; Moritz, Max A; Sherriff, Rosemary L; Veblen, Thomas T; Williams, Mark A

    2014-01-01

    There is widespread concern that fire exclusion has led to an unprecedented threat of uncharacteristically severe fires in ponderosa pine (Pinus ponderosa Dougl. ex. Laws) and mixed-conifer forests of western North America. These extensive montane forests are considered to be adapted to a low/moderate-severity fire regime that maintained stands of relatively old trees. However, there is increasing recognition from landscape-scale assessments that, prior to any significant effects of fire exclusion, fires and forest structure were more variable in these forests. Biota in these forests are also dependent on the resources made available by higher-severity fire. A better understanding of historical fire regimes in the ponderosa pine and mixed-conifer forests of western North America is therefore needed to define reference conditions and help maintain characteristic ecological diversity of these systems. We compiled landscape-scale evidence of historical fire severity patterns in the ponderosa pine and mixed-conifer forests from published literature sources and stand ages available from the Forest Inventory and Analysis program in the USA. The consensus from this evidence is that the traditional reference conditions of low-severity fire regimes are inaccurate for most forests of western North America. Instead, most forests appear to have been characterized by mixed-severity fire that included ecologically significant amounts of weather-driven, high-severity fire. Diverse forests in different stages of succession, with a high proportion in relatively young stages, occurred prior to fire exclusion. Over the past century, successional diversity created by fire decreased. Our findings suggest that ecological management goals that incorporate successional diversity created by fire may support characteristic biodiversity, whereas current attempts to "restore" forests to open, low-severity fire conditions may not align with historical reference conditions in most ponderosa

  13. Examining historical and current mixed-severity fire regimes in ponderosa pine and mixed-conifer forests of western North America.

    Directory of Open Access Journals (Sweden)

    Dennis C Odion

    Full Text Available There is widespread concern that fire exclusion has led to an unprecedented threat of uncharacteristically severe fires in ponderosa pine (Pinus ponderosa Dougl. ex. Laws and mixed-conifer forests of western North America. These extensive montane forests are considered to be adapted to a low/moderate-severity fire regime that maintained stands of relatively old trees. However, there is increasing recognition from landscape-scale assessments that, prior to any significant effects of fire exclusion, fires and forest structure were more variable in these forests. Biota in these forests are also dependent on the resources made available by higher-severity fire. A better understanding of historical fire regimes in the ponderosa pine and mixed-conifer forests of western North America is therefore needed to define reference conditions and help maintain characteristic ecological diversity of these systems. We compiled landscape-scale evidence of historical fire severity patterns in the ponderosa pine and mixed-conifer forests from published literature sources and stand ages available from the Forest Inventory and Analysis program in the USA. The consensus from this evidence is that the traditional reference conditions of low-severity fire regimes are inaccurate for most forests of western North America. Instead, most forests appear to have been characterized by mixed-severity fire that included ecologically significant amounts of weather-driven, high-severity fire. Diverse forests in different stages of succession, with a high proportion in relatively young stages, occurred prior to fire exclusion. Over the past century, successional diversity created by fire decreased. Our findings suggest that ecological management goals that incorporate successional diversity created by fire may support characteristic biodiversity, whereas current attempts to "restore" forests to open, low-severity fire conditions may not align with historical reference conditions in

  14. An integrated model of environmental effects on growth, carbohydrate balance, and mortality of Pinus ponderosa forests in the southern Rocky Mountains.

    Directory of Open Access Journals (Sweden)

    Christina L Tague

    Full Text Available Climate-induced tree mortality is an increasing concern for forest managers around the world. We used a coupled hydrologic and ecosystem carbon cycling model to assess temperature and precipitation impacts on productivity and survival of ponderosa pine (Pinus ponderosa. Model predictions were evaluated using observations of productivity and survival for three ponderosa pine stands located across an 800 m elevation gradient in the southern Rocky Mountains, USA, during a 10-year period that ended in a severe drought and extensive tree mortality at the lowest elevation site. We demonstrate the utility of a relatively simple representation of declines in non-structural carbohydrate (NSC as an approach for estimating patterns of ponderosa pine vulnerability to drought and the likelihood of survival along an elevation gradient. We assess the sensitivity of simulated net primary production, NSC storage dynamics, and mortality to site climate and soil characteristics as well as uncertainty in the allocation of carbon to the NSC pool. For a fairly wide set of assumptions, the model estimates captured elevational gradients and temporal patterns in growth and biomass. Model results that best predict mortality risk also yield productivity, leaf area, and biomass estimates that are qualitatively consistent with observations across the sites. Using this constrained set of parameters, we found that productivity and likelihood of survival were equally dependent on elevation-driven variation in temperature and precipitation. Our results demonstrate the potential for a coupled hydrology-ecosystem carbon cycling model that includes a simple model of NSC dynamics to predict drought-related mortality. Given that increases in temperature and in the frequency and severity of drought are predicted for a broad range of ponderosa pine and other western North America conifer forest habitats, the model potentially has broad utility for assessing ecosystem vulnerabilities.

  15. 塑料裙干基密闭熏蒸法防治红脂大小蠹试验%Basal airtight fumigation in plastic skirts against Dendroctonus valens

    Institute of Scientific and Technical Information of China (English)

    苗振旺; 郭保平; 张晓波; 王晓俪; 赵明梅; 芦学林

    2002-01-01

    红脂大小蠹 Dendroctonus valens LeConte 是危害油松的国内新纪录种.在红脂大小蠹主要侵入部位,树干距地面50cm的主干上用0.06mm厚度的塑料布围成塑料裙,内置56%的磷化铝片剂(3.2g/片),每株3~4片进行密闭熏杀防治红脂大小蠹,效果可达93.6%以上.

  16. 华山松大小蠹不同龄期幼虫酯酶同工酶的比较研究%Study on Esterase Isoenzymes of Dendroctonus armandi Larvae in Different Growth Periods

    Institute of Scientific and Technical Information of China (English)

    谢寿安; 吕淑杰; 袁锋; 刘紫英

    2002-01-01

    利用聚丙烯酰胺凝胶电泳技术对华山松大小蠹(Dendroctonus armandi)不同龄期幼虫的酯酶同工酶进行了分析测试.结果表明华山松大小蠹不同龄期幼虫的酯酶同工酶具有个体间的差异,其差异主要表现在酶带带数、迁移率、酶带染色深浅、酶带宽窄等方面.

  17. 北京地区红脂大小蠹空间分布型与抽样技术研究%The spatial distribution pattern and sampling technique of Dendroctonus valens in Beijing

    Institute of Scientific and Technical Information of China (English)

    潘杰; 王涛; 宗世祥; 温俊宝; 骆有庆

    2010-01-01

    对北京地区红脂大小蠹Dendroctonus valens LeConte空间分布型进行了研究.结果表明红脂大小蠹成聚集分布,其聚集原因是由红脂大小蠹本身的聚集行为或聚集行为与环境的异质性共同作用引起.同时,应用Iwao统计方法,提出了最适理论抽样数和最佳序贯抽样模型.

  18. 红脂大小蠹、华山松大小蠹和云杉大小蠹形态学比较%On External Structure of Dendroctonus valens、D. armandi and D. micans

    Institute of Scientific and Technical Information of China (English)

    吕淑杰; 谢寿安; 张军灵; 李大寨

    2002-01-01

    对陕西省渭南地区的红脂大小蠹(Dendroctonus valens)、秦巴林区的华山松大小蠹 (D. armandi)和祁连山林区的云杉大小蠹(D. micans)的形态学进行了比较研究,结果表明,3种大小蠹在形态特征、危害症状等方面有显著差异.

  19. Strategies for preventing invasive plant outbreaks after prescribed fire in ponderosa pine forest

    Science.gov (United States)

    Symstad, Amy J.; Newton, Wesley E.; Swanson, Daniel J.

    2014-01-01

    Land managers use prescribed fire to return a vital process to fire-adapted ecosystems, restore forest structure from a state altered by long-term fire suppression, and reduce wildfire intensity. However, fire often produces favorable conditions for invasive plant species, particularly if it is intense enough to reveal bare mineral soil and open previously closed canopies. Understanding the environmental or fire characteristics that explain post-fire invasive plant abundance would aid managers in efficiently finding and quickly responding to fire-caused infestations. To that end, we used an information-theoretic model-selection approach to assess the relative importance of abiotic environmental characteristics (topoedaphic position, distance from roads), pre-and post-fire biotic environmental characteristics (forest structure, understory vegetation, fuel load), and prescribed fire severity (measured in four different ways) in explaining invasive plant cover in ponderosa pine forest in South Dakota’s Black Hills. Environmental characteristics (distance from roads and post-fire forest structure) alone provided the most explanation of variation (26%) in post-fire cover of Verbascum thapsus (common mullein), but a combination of surface fire severity and environmental characteristics (pre-fire forest structure and distance from roads) explained 36–39% of the variation in post-fire cover of Cirsium arvense (Canada thistle) and all invasives together. For four species and all invasives together, their pre-fire cover explained more variation (26–82%) in post-fire cover than environmental and fire characteristics did, suggesting one strategy for reducing post-fire invasive outbreaks may be to find and control invasives before the fire. Finding them may be difficult, however, since pre-fire environmental characteristics explained only 20% of variation in pre-fire total invasive cover, and less for individual species. Thus, moderating fire intensity or targeting areas

  20. Effect of body condition on consumption of pine needles (Pinus ponderosa) by beef cows.

    Science.gov (United States)

    Pfister, J A; Panter, K E; Gardner, D R; Cook, D; Welch, K D

    2008-12-01

    We determined whether cows in low (LBC) or high body condition (HBC) would consume different amounts of green pine needles (Pinus ponderosa). Cows (mature; open Hereford and Hereford x Angus) were fed a maintenance basal diet (alfalfa pellets) for Exp. 1 and 2; during Exp. 3 and 4, cows were fed high-protein and high-energy diets, respectively. Experiment 5 was a grazing study on rangeland during winter in South Dakota; diets were determined by using bite counts. Mean BCS (1 = emaciated, 9 = obese) was 7.5 for HBC cows and pine needles than did HBC cows (5.5 +/- 0.25 vs. 1.0 +/- 0.14 g/kg of BW daily, respectively). During Exp. 2, there was a day x treatment interaction (P = 0.001) as LBC cows consumed variable, but greater, amounts of pine needles than did HBC cows (3.7 +/- 0.19 vs. 1.3 +/- 0.12 g/kg of BW daily, respectively). When fed a high-protein/low-energy diet, LBC cows ate more (P = 0.04) pine needles than did HBC cows. When fed a low-protein/high-energy diet, there was a day x treatment interaction (P = 0.001) because LBC cows consumed more pine needles than did HBC cows for the first 3 d of the study, and then consumption by LBC animals decreased during the last 4 d. These experiments suggest that the protein:energy ratio may be an important factor in the ability of cows to tolerate terpenes, and that cows were not able to sustain an increased quantity of needle consumption on a low-protein diet. During the 25-d grazing study, there was a day x treatment interaction (P = 0.001) as LBC animals selected more pine needles (up to 25% of daily bites) on some days compared with HBC cows. Weather influenced pine needle consumption because pine needle bites by LBC cows were related (r(2) = 0.60; P = 0.001) to days of greater snow depth and lower minimum daily temperatures. Both LBC and HBC cows increased selection of pine needles from trees during cold, snowy weather, but the magnitude of the increase was greater for LBC cows. The LBC cows consumed more pine

  1. Eddy covariance methane measurements at a Ponderosa pine plantation in California

    Directory of Open Access Journals (Sweden)

    C. J. P. P. Smeets

    2009-02-01

    Full Text Available Long term methane flux measurements have been mostly performed with plant or soil enclosure techniques on specific components of an ecosystem. New fast response methane analyzers make it possible to use the eddy covariance (EC technique instead. The EC technique is advantageous because it allows continuous flux measurements integrating over a larger and more representative area including the complete ecosystem, and allows fluxes to be observed as environmental conditions change naturally without disturbance. We deployed the closed-path Fast Methane Analyser (FMA from Los Gatos Research Ltd and demonstrate its performance for EC measurements at a Ponderosa pine plantation at the Blodgett Forest site in central California. CH4 concentrations measured at 10 Hz showed a relatively high noise level that was caused by a software related problem. Nevertheless, in the frequency range important for turbulent exchange, the cospectra of CH4 compare very well with all other scalar cospectra confirming the quality of the FMA measurements are good for the EC technique. The low-pass filtering characteristics of our closed-path system and the use of the Webb-Pearman-Leuning (WPL corrections for a combination of open and closed-path sensors are discussed using a large ensemble of cospectra. The diurnal variation of the methane concentration was up to 60 ppbv with an average of 1843 ppbv. Concentrations increased from morning to late afternoon as upslope flow from the valley below carried polluted air to the site, and then decreased through the night as downslope flow carried cleaner air from aloft. The fluxes were consistently directed downward with a well defined diurnal pattern, averaging −35±40 ng m−2 s−1 during the daytime. The detection limit of the system was estimated at 22 ng m−2 s−1. The average CH4 deposition during the daytime was higher than the average value for

  2. Litter and dead wood dynamics in ponderosa pine forests along a 160-year chronosequence.

    Science.gov (United States)

    Hall, S A; Burke, I C; Hobbs, N T

    2006-12-01

    Disturbances such as fire play a key role in controlling ecosystem structure. In fire-prone forests, organic detritus comprises a large pool of carbon and can control the frequency and intensity of fire. The ponderosa pine forests of the Colorado Front Range, USA, where fire has been suppressed for a century, provide an ideal system for studying the long-term dynamics of detrital pools. Our objectives were (1) to quantify the long-term temporal dynamics of detrital pools; and (2) to determine to what extent present stand structure, topography, and soils constrain these dynamics. We collected data on downed dead wood, litter, duff (partially decomposed litter on the forest floor), stand structure, topographic position, and soils for 31 sites along a 160-year chronosequence. We developed a compartment model and parameterized it to describe the temporal trends in the detrital pools. We then developed four sets of statistical models, quantifying the hypothesized relationship between pool size and (1) stand structure, (2) topography, (3) soils variables, and (4) time since fire. We contrasted how much support each hypothesis had in the data using Akaike's Information Criterion (AIC). Time since fire explained 39-80% of the variability in dead wood of different size classes. Pool size increased to a peak as material killed by the fire fell, then decomposed rapidly to a minimum (61-85 years after fire for the different pools). It then increased, presumably as new detritus was produced by the regenerating stand. Litter was most strongly related to canopy cover (r2 = 77%), suggesting that litter fall, rather than decomposition, controls its dynamics. The temporal dynamics of duff were the hardest to predict. Detrital pool sizes were more strongly related to time since fire than to environmental variables. Woody debris peak-to-minimum time was 46-67 years, overlapping the range of historical fire return intervals (1 to > 100 years). Fires may therefore have burned under a

  3. Distribution of black carbon in ponderosa pine forest floor and soils following the High Park wildfire

    Science.gov (United States)

    Boot, C. M.; Haddix, M.; Paustian, K.; Cotrufo, M. F.

    2015-05-01

    Biomass burning produces black carbon (BC), effectively transferring a fraction of the biomass C from an actively cycling pool to a passive C pool, which may be stored in the soil. Yet the timescales and mechanisms for incorporation of BC into the soil profile are not well understood. The High Park fire (HPF), which occurred in northwestern Colorado in the summer of 2012, provided an opportunity to study the effects of both fire severity and geomorphology on properties of carbon (C), nitrogen (N) and BC in the Cache La Poudre River drainage. We sampled montane ponderosa pine forest floor (litter plus O-horizon) and soils at 0-5 and 5-15 cm depth 4 months post-fire in order to examine the effects of slope and burn severity on %C, C stocks, %N and BC. We used the benzene polycarboxylic acid (BPCA) method for quantifying BC. With regard to slope, we found that steeper slopes had higher C : N than shallow slopes but that there was no difference in BPCA-C content or stocks. BC content was greatest in the forest floor at burned sites (19 g BPCA-C kg-1 C), while BC stocks were greatest in the 5-15 cm subsurface soils (23 g BPCA-C m-2). At the time of sampling, unburned and burned soils had equivalent BC content, indicating none of the BC deposited on the land surface post-fire had been incorporated into either the 0-5 or 5-15 cm soil layers. The ratio of B6CA : total BPCAs, an index of the degree of aromatic C condensation, suggested that BC in the 5-15 cm soil layer may have been formed at higher temperatures or experienced selective degradation relative to the forest floor and 0-5 cm soils. Total BC soil stocks were relatively low compared to other fire-prone grassland and boreal forest systems, indicating most of the BC produced in this system is likely lost, either through erosion events, degradation or translocation to deeper soils. Future work examining mechanisms for BC losses from forest soils will be required for understanding the role BC plays in the global

  4. Effects of CO{sub 2} and nitrogen fertilization on soils planted with ponderosa pine

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.W.

    1996-12-01

    The effects of elevated CO{sub 2} (ambient, 525, and 700 {micro}l l{sup -1})and N fertilization (0, 10, and 20 g N m{sup 2} yr{sup -1}) on soil pCO{sub 2}, CO{sub 2} efflux, soil solution chemistry, and soil C and nutrients in an open-top chamber study with Pinus ponderosa are described. Soil pCO{sub 2} and CO{sub 2} efflux were significantly greater with elevated CO{sub 2}, at first (second growing season) in the 525 {micro}l l{sup -1} and later (fourth and fifth growing seasons) in the 700 {micro}l l{sup -1} CO{sub 2} treatments. Soil solution HCO{sub 3}{sup -} concentrations were temporarily elevated in the 525 {micro}l l{sup -1} CO{sub 2} treatment during the second growing season, consistent with the elevated pCO{sub 2}. Nitrogen fertilization had no consistent effect on soil pCO{sub 2} or CO{sub 2} efflux, but did have the expected negative effect on exchangeable Ca{sup 2+}, K{sup +}, and Mg{sup 2+}, presumed to be caused by increased nitrate leaching. Elevated CO{sub 2} had no consistent effects on exchangeable Ca{sup 2+}, K{sup +}, and Mg{sup 2+}, but did cause temporary reductions in soil NO{sup 3{sup -}} (second growing season). Statistically significant negative effects of elevated CO{sub 2} on soil extractable P were noted in the third and sixth growing seasons. However, these patterns in extractable P reflected pre-treatment differences, which, while not statistically significant, followed the same pattern. Statistically significant effects of elevated CO{sub 2} on total C and N in soils were noted in the third and sixth growing seasons, but these effects were inconsistent among N treatments and years. The clearest effect of elevated CO{sub 2} was in the case of C/N ratio in year 6, where there was a consistent, positive effect. The increases in C/N ratio with elevated CO{sub 2} in year six were largely a result of reductions in soil N rather than increases in soil C. Future papers will assess whether this apparent reduction in soil N could have been

  5. Variable responses by southern pine beetle, Dendroctonus frontalis Zimmermann, to the pheromone component endo-brevicomin: influence of enantiomeric composition, release rate, and proximity to infestations.

    Science.gov (United States)

    Sullivan, Brian T; Dalusky, Mark J; Mori, Kenji; Brownie, Cavell

    2011-04-01

    The male-produced bicyclic acetal endo-brevicomin is a component of the pheromone blend that mediates colonization of host pines by the bark beetle Dendroctonus frontalis Zimmermann. Efforts to identify its behavioral function have been complicated by contrasting reports that it either enhances or reduces attraction of flying beetles. Our studies failed to support the hypothesis that this published variability is due to differences in release rate and/or the enantiomeric composition [i.e., the beetle-produced (+)-enantiomer vs. the racemate] of the endo-brevicomin used in the experiments. In trapping trials within active D. frontalis infestations, racemic and (+)-endo-brevicomin did not differ from each other in behavioral effects when tested at seven different release rates ranging from 0.005 to 3 mg/d. At the highest release rates, racemic and (+)-endo-brevicomin similarly reduced catches in traps baited with an attractant (frontalin and turpentine), but neither enhanced catches at any release rate. Furthermore, the activity of racemic endo-brevicomin baits depended on trap proximity to D. frontalis infestations. Addition of these baits to attractant-baited traps located inside active infestations reduced catches, but they enhanced catches at traps located either 100 or 200 m outside these infestations. The contrasting responses may reflect differences in host-seeking strategies by either aggregated or dispersing D. frontalis, and may be elicited by differing abundance of natural sources of semiochemicals or differing responsiveness of beetles inside vs. outside of infestations. We suspect that much of the published variability in D. frontalis responses to endo-brevicomin is attributable to differing proximity of experimental field sites to infestations.

  6. Respuesta kairomonal de coleópteros asociados a Dendroctonus frontalis y dos especies de Ips (Coleoptera: Curculionidae en bosques de Chiapas, México Kairomonal response of coleopterans associated with Dendroctonus frontalis and two Ips species (Coleoptera: Curculionidae in forest of Chiapas, Mexico

    Directory of Open Access Journals (Sweden)

    Bernardo Domínguez-Sánchez

    2008-06-01

    Full Text Available Se evaluó la diversidad de escarabajos descortezadores y la respuesta diferencial de sus coleópteros asociados a feromonas comerciales de agregación, en bosques de pino del estado de Chiapas, México. Durante los meses de junio a octubre del 2006, se colocaron 40 trampas multiembudo tipo Lindgren cebadas con las feromonas racémicas frontalina, ipsenol e ipsdienol y un testigo (sin feromona. La captura fue más abundante para los escarabajos descortezadores Dendroctonus frontalis (Zimmermann con frontalina, y de Ips spp. con ipsenol e ipsdienol. Se registró respuesta kairomonal específica de los depredadores Temnochila chlorodia (Mannerheim, Enoclerus ablusus (Barr y Elacatis sp. hacia las feromonas de agregación. Tanto para descortezadores como para depredadores, las mayores abundancias fueron registradas durante el verano y a comienzos del otoño. Temmnochila chlorodia exhibió una atracción diferencial hacia los semioquímicos evaluados, mientras que E. ablusus, Elacatis sp. y Leptostylus sp. fueron atraídos principalmente por las feromonas ipsenol e ipsdienol. Además, por primera vez para México se determinó la respuesta kairomonal del fitófago Leptostylus sp. (Cerambycidae. Estos resultados indican que hay una comunicación intra e inter específica entre los escarabajos descortezadores y sus especies asociadas que promueven interacciones de competencia y depredación.We assessed the bark beetle diversity and the response of associated predators to aggregation pheromones in pine forests in Chiapas, Mexico. From June to October 2006, 40 Lindgren funnel traps were established with different baits that included frontalin, ipsenol and ipsdienol pheromones and a control (without pheromone. We registered the attractiveness of frontalin to the bark beetle Dendroctonus frontalis (Zimmermann, and ipsenol and ipsdienol to Ips spp. Kairomonal specific response of the predators Temnochila chlorodia (Mannerheim, Enoclerus ablusus (Barr and

  7. Primer registro de Naupactus ruizi (Coleoptera: Curculionoidea asociado con Pinus ponderosa (Gymnospermae: Pinaceae en Patagonia First record of Naupactus ruizi (Coleoptera: Curculionoidea associated to Pinus ponderosa (Gymnospermae: Pinaceae in Patagonia

    Directory of Open Access Journals (Sweden)

    Cecilia A. Gómez

    2006-07-01

    Full Text Available Naupactus ruizi (Brèthes es un gorgojo de rostro corto, distribuido en la Argentina y Chile, que habita en ambientes áridos asociado con vegetación xerofítica y alcanza el rango más austral entre los miembros de la tribu Naupactini. Un relevamiento de insectos y de patógenos como plagas potenciales, realizado durante el 2005 en plantaciones de Pinus spp. en la Patagonia andina argentina, resultó en el hallazgo de adultos de N. ruizi que se alimentaban de acículas de Pinus ponderosa Dougl. ex Laws. Este hallazgo es sorprendente dado que las especies de Naupactini, consumen casi exclusivamente angiospermas. Interpretamos que el cambio de huésped, habría ocurrido como consecuencia de una colonización reciente favorecida por la amplia distribución geográfica del gorgojo y su capacidad para sobrevivir en hábitats marginales, donde probablemente las plantas nativas son escasas y el nuevo huésped presenta una gran abundancia local.Naupactus ruizi (Brèthes is a broad-nosed weevil recorded from Argentina and Chile , that inhabits arid environments with xerophitic vegetation and reaches the southern most distribution of the tribe Naupactini. A survey of potential insect pests and pathogens of plantations of Pinus spp. and other forest species, conducted during 2005 in Argentinean Patagonian Andean forestations, allowed to find N. ruizi feeding on pine needles of Pinus ponderosa Dougl. ex Laws. This finding was unexpected, since species of Naupactini consume almost exclusively angiosperms. We interpret that the new host association may represent a recent host shift, probably facilitated by the broad range of the weevil, its capacity to survive in marginal habitats where natural hosts are scarce, and the local abundance of the new host.

  8. Combustion characteristics of Ponderosa Pine bark. Technical progress report No. 7, September 16, 1977--September 15, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Junge, D.C.

    1978-12-01

    Significant quantities of wood residue fuels are presently being used in industrial steam generating facilities. Recent studies indicate that substantial additional quantities of wood residue fuels are available for energy generation in the form of steam and/or electricity. A limited data base on the combustion characteristics of wood residue fuels has resulted in the installation and operation of inefficient combustion systems for these fuels. This investigation of the combustion characteristics of wood residue fuels was undertaken to provide a data base which could be used to optimize the combustion of such fuels. Optimization of the combustion process in industrial boilers serves to improve combustion efficiency and to reduce air pollutant emissions generated in the combustion process. Data are presented on the combustion characteristics of Ponderosa Pine bark. The data were obtained in a pilot scale combustion test facility at Oregon State University.

  9. Mountain Pine Beetle

    Science.gov (United States)

    Gene D. Amman; Mark D. McGregor; Robert E. Jr. Dolph

    1989-01-01

    The mountain pine beetle, Dendroctonus ponderosae Hopkins, is a member of a group of beetles known as bark beetles: Except when adults emerge and attack new trees, the mountain pine beetle completes its life cycle under the bark. The beetle attacks and kills lodgepole, ponderosa, sugar, and western white pines. Outbreaks frequently develop in lodgepole pine stands that...

  10. Mountain pine beetle, a major disturbance agent in US Western coniferous forests: A synthesis of the state of knowledge [Research In Review

    Science.gov (United States)

    Jose F. Negron; Christopher J. Fettig

    2014-01-01

    In recent years, the mountain pine beetle, Dendroctonus ponderosae, has impacted 8.9 million hectares of forests in the western United States. Historically a common occurrence in western forests, particularly in lodgepole and ponderosa pine, the magnitude and extent of recent outbreaks have exceeded past events since written records are available and have occurred in...

  11. Influences of canopy photosynthesis and summer rain pulses on root dynamics and soil respiration in a young ponderosa pine forest.

    Science.gov (United States)

    Misson, Laurent; Gershenson, Alexander; Tang, Jianwu; McKay, Megan; Cheng, Weixin; Goldstein, Allen

    2006-07-01

    Our first objective was to link the seasonality of fine root dynamics with soil respiration in a ponderosa pine (Pinus ponderosa P. & C. Lawson) plantation located in the Sierra Nevada of California. The second objective was to examine how canopy photosynthesis influences fine root initiation, growth and mortality in this ecosystem. We compared CO2 flux measurements with aboveground and belowground root dynamics. Initiation of fine root growth coincided with tree stem thickening and shoot elongation, preceding new needle growth. In the spring, root, shoot and stem growth occurred simultaneously with the increase in canopy photosynthesis. Compared with the other tree components, initial growth rate of fine roots was the highest and their growing period was the shortest. Both above and belowground components completed 90% of their growth by the end of July and the growing season lasted approximately 80 days. The period for optimal growth is short at the study site because of low soil temperatures during winter and low soil water content during summer. High photosynthetic rates were observed following unusual late-summer rains, but tree growth did not resume. The autotrophic contribution to soil respiration was 49% over the whole season, with daily contributions ranging between 18 and 87%. Increases in soil and ecosystem respiration were observed during spring growth; however, the largest variation in soil respiration occurred during summer rain events when no growth was observed. Both the magnitude and persistence of the soil respiration pulses were positively correlated with the amount of rain. These pulses accounted for 16.5% of soil respiration between Days 130 and 329.

  12. Response of brown-headed cowbirds and three host species to thinning treatments in low-elevation ponderosa pine forests along the northern Colorado Front Range

    Science.gov (United States)

    Keeley, W.H.; Germaine, Stephen S.; Stanley, Thomas R.; Spaulding, Sarah A.; Wanner, C.E.

    2013-01-01

    Thinning ponderosa pine (Pinus ponderosa) forests to achieve desired ecological conditions remains a priority in the North American west. In addition to reducing the risk of high-severity wildfires in unwanted areas, stand thinning may increase wildlife and plant diversity and provide increased opportunity for seedling recruitment. We initiated conservative (i.e. minimal removal of trees) ponderosa stand thinning treatments with the goals of reducing fire risk and improving habitat conditions for native wildlife and flora. We then compared site occupancy of brown-headed cowbirds (Molothrus ater), chipping sparrows (Spizella passerina), plumbeous vireos (Vireo plumbeus), and western wood-pewees (Contopus sordidulus) in thinned and unthinned (i.e., control) forest stands from 2007 to 2009. Survey stations located in thinned stands had 64% fewer trees/ha, 25% less canopy cover, and 23% less basal area than stations in control stands. Occupancy by all three host species was negatively associated with tree density, suggesting that these species respond favorably to forest thinning treatments in ponderosa pine forests. We also encountered plumbeous vireos more frequently in plots closer to an ecotonal (forest/grassland) edge, an association that may increase their susceptibility to edge-specialist, brood parasites like brown-headed cowbirds. Occupancy of brown-headed cowbirds was not related to forest metrics but was related to occupancy by plumbeous vireos and the other host species in aggregate, supporting previous reports on the affiliation between these species. Forest management practices that promote heterogeneity in forest stand structure may benefit songbird populations in our area, but these treatments may also confer costs associated with increased cowbird occupancy. Further research is required to understand more on the complex relationships between occupancy of cowbirds and host species, and between cowbird occupancy and realized rates of nest parasitism.

  13. Isolation and expression of HMG-CoA synthase and HMG-CoA reductase genes in different development stages, tissues and treatments of the Chinese white pine beetle, Dendroctonus armandi (Curculionidae: Scolytinae).

    Science.gov (United States)

    Yu, Jiamin; Dai, Lulu; Zhang, Ranran; Li, Zhumei; Pham, Thanh; Chen, Hui

    2015-09-01

    We isolated two full-length cDNAs encoding 3-hydroxy-3-methyl-glutaryl coenzyme A synthase (HMG-S) and 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-R) from the Chinese white pine beetle (Dendroctonus armandi), and carried out some bioinformatic analysis on the full-length nucleic acid sequences and deduced amino acid sequences. Differential expression of the DaHMG-S and DaHMG-R genes was observed between sexes (emerged adults), and within these significant differences among development stage, tissue distribution, fed on phloem of Pinus armandi and topically applied juvenile hormone (JH) III. Increase of DaHMG-S and DaHMG-R mRNA levels in males suggested that they may play a role in mevalonate pathway. Information from the present study might contribute to understanding the relationship between D. armandi and its semiochemical production. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. 进境原木上截获的落叶松大小蠹及其扩散风险浅析%Dendroctonus simplex from the imported log and the risk analysis of its spread

    Institute of Scientific and Technical Information of China (English)

    郑茂灿; 叶剑雄; 徐清元

    2007-01-01

    2006年,莆田口岸先后几次从美国阿拉斯加进口原木中截获到一种大小蠹,经鉴定复核,确定为落叶松大小蠹(Dendroctonus simplex Leconte).该种在国内未见分布和相关研究报道.本文详细描述了落叶松大小蠹的形态特征、地理分布、寄主植物、生物学特性及危害等,并对其检疫重要性进行了分析.

  15. Study on Attractant Effect of Different Traps on Dendroctonus valens%不同诱捕器对红脂大小蠹引诱效果的研究

    Institute of Scientific and Technical Information of China (English)

    孙永明; 樊慧萍; 苗俊玲

    2004-01-01

    选用十字型诱捕器、漏斗型诱捕器、狭槽型诱捕器、粘虫胶型诱捕器,采用随机区组的研究方法,在林间对红脂大小蠹(Dendroctonus valens Leconte)进行了引诱效果的研究.结果表明,十字型诱捕器对红脂大小蠹的引诱效果最好,漏斗型诱捕器和狭槽型诱捕器次之,但与十字型诱捕器诱捕量的差异不显著,粘虫胶型诱捕器引诱效果极差,建议在生产中推广使用十字型诱捕器.

  16. Isolation and extreme sex-specific expression of cytochrome P450 genes in the bark beetle, Ips paraconfusus, following feeding on the phloem of host ponderosa pine, Pinus ponderosa.

    Science.gov (United States)

    Huber, D P W; Erickson, M L; Leutenegger, C M; Bohlmann, J; Seybold, S J

    2007-06-01

    We have identified cDNAs and characterized the expression of 13 novel cytochrome P450 genes of potential importance in host colonization and reproduction by the California fivespined ips, Ips paraconfusus. Twelve are of the Cyp4 family and one is of the Cyp9 family. Following feeding on host Pinus ponderosa phloem, bark beetle transcript levels of several of the Cyp4 genes increased or decreased in males only or in both sexes. In one instance (IparaCyp4A5) transcript accumulated significantly in females, but declined significantly in males. The Cyp9 gene (Cyp9T1) transcript levels in males were > 85 000 x higher at 8 h and > 25 000 x higher at 24 h after feeding compared with nonfed controls. Transcript levels in females were approximately 150 x higher at 24 h compared with nonfed controls. Cyp4G27 transcript was present constitutively regardless of sex or feeding and served as a better housekeeping gene than beta-actin or 18S rRNA for the real-time TaqMan polymerase chain reaction analysis. The expression patterns of Cyp4AY1, Cyp4BG1, and, especially, Cyp9T1 in males suggest roles for these genes in male-specific aggregation pheromone production. The differential transcript accumulation patterns of these bark beetle P450s provide insight into ecological interactions of I. paraconfusus with its host pines.

  17. Prediction on potential distributions of Dendroctonus frontalis Zimmermann in China using CLIMEX and GIS%基于CLIMEX和GIS的南松大小蠹在中国的适生性分析

    Institute of Scientific and Technical Information of China (English)

    姚剑; 杜宇; 马平; 李生贵; 蒋小龙; 陈雪娇; 张萍; 李云飞

    2011-01-01

    南松大小蠹Dendroctonus frontalis Zimmermann是美洲地区危害松杉类针叶树种的蛀干害虫.本文采用CLIMEX模型与ArcGIS分析相结合的预测方法,通过确定南松大小蠹的CLIMEX气候适应性参数,分析了南松大小蠹在我国的适生范围,并利用南松大小蠹的最低致死温度对适生范围进行限制.结果表明南松大小蠢在我国可能适宜其定殖的地区范围较广,其中在山东、河南、陕西、安徽中北部、山西南部、湖北中北部、四川部分地区和云南部分地区非常适合该小蠹的生存.%Dendroctonus frontalis Zimmermann is one of the most economically important pests of Pinus plantations in America. Based on the biology of D. frontalis and climate data, potential suitable habitat for D. frontalis in China was predicted using CLIMEX and ArcGIS. The results show that D. frontalis has a wide potential distribution in China.Predicted optimum areas for establishment were most of north and southwestern China, including Shandong, Henan,Shanxi, Anhui, Shanxi, Hubei, Sichuan, Yunnan.

  18. Impact of prescribed fire and other factors on cheatgrass persistence in a Sierra Nevada ponderosa pine forest

    Science.gov (United States)

    Keeley, J.E.; McGinnis, T.W.

    2007-01-01

    Following the reintroduction of fire Bromus tectorum has invaded the low elevation ponderosa pine forests in parts of Kings Canyon National Park, California. We used prescribed burns, other field manipulations, germination studies, and structural equation modelling, to investigate how fire and other factors affect the persistence of cheatgrass in these forests. Our studies show that altering burning season to coincide with seed maturation is not likely to control cheatgrass because sparse fuel loads generate low fire intensity. Increasing time between prescribed fires may inhibit cheatgrass by increasing surface fuels (both herbaceous and litter), which directly inhibit cheatgrass establishment, and by creating higher intensity fires capable of killing a much greater fraction of the seed bank. Using structural equation modelling, postfire cheatgrass dominance was shown to be most strongly controlled by the prefire cheatgrass seedbank; other factors include soil moisture, fire intensity, soil N, and duration of direct sunlight. Current fire management goals in western conifer forests are focused on restoring historical fire regimes; however, these frequent fire regimes may enhance alien plant invasion in some forest types. Where feasible, fire managers should consider the option of an appropriate compromise between reducing serious fire hazards and exacerbating alien plant invasions. ?? IAWF 2007.

  19. Growing season soil moisture following restoration treatments of varying intensity in semi-arid ponderosa pine forests

    Science.gov (United States)

    O'Donnell, F. C.; Springer, A. E.; Sankey, T.; Masek Lopez, S.

    2014-12-01

    Forest restoration projects are being planned for large areas of overgrown semi-arid ponderosa pine forests of the Southwestern US. Restoration involves the thinning of smaller trees and prescribed or managed fire to reduce tree density, restore a more natural fire regime, and decrease the risk of catastrophic wildfire. The stated goals of these projects generally reduced plant water stress and improvements in hydrologic function. However, little is known about how to design restoration treatments to best meet these goals. As part of a larger project on snow cover, soil moisture, and groundwater recharge, we measured soil moisture, an indicator of plant water status, in four pairs of control and restored sites near Flagstaff, Arizona. The restoration strategies used at the sites range in both amount of open space created and degree of clustering of the remaining trees. We measured soil moisture using 30 cm vertical time domain reflectometry probes installed on 100 m transects at 5 m intervals so it would be possible to analyze the spatial pattern of soil moisture. Soil moisture was higher and more spatially variable in the restored sites than the control sites with differences in spatial pattern among the restoration types. Soil moisture monitoring will continue until the first snow fall, at which point measurements of snow depth and snow water equivalent will be made at the same locations.

  20. Climatic Versus Biotic Constraints on Carbon and Water Fluxes in Seasonally Drought-affected Ponderosa Pine Ecosystems. Chapter 2

    Science.gov (United States)

    Schwarz, P. A.; Law, B. E.; Williams, M.; Irvine, J.; Kurpius, M.; Moore, D.

    2005-01-01

    We investigated the relative importance of climatic versus biotic controls on gross primary production (GPP) and water vapor fluxes in seasonally drought-affected ponderosa pine forests. The study was conducted in young (YS), mature (MS), and old stands (OS) over 4 years at the AmeriFlux Metolius sites. Model simulations showed that interannual variation of GPP did not follow the same trends as precipitation, and effects of climatic variation were smallest at the OS (50%), and intermediate at the YS (<20%). In the young, developing stand, interannual variation in leaf area has larger effects on fluxes than climate, although leaf area is a function of climate in that climate can interact with age-related shifts in carbon allocation and affect whole-tree hydraulic conductance. Older forests, with well-established root systems, appear to be better buffered from effects of seasonal drought and interannual climatic variation. Interannual variation of net ecosystem exchange (NEE) was also lowest at the OS, where NEE is controlled more by interannual variation of ecosystem respiration, 70% of which is from soil, than by the variation of GPP, whereas variation in GPP is the primary reason for interannual changes in NEE at the YS and MS. Across spatially heterogeneous landscapes with high frequency of younger stands resulting from natural and anthropogenic disturbances, interannual climatic variation and change in leaf area are likely to result in large interannual variation in GPP and NEE.

  1. Alteration of foliar flavonoid chemistry induced by enhanced UV-B radiation in field-grown Pinus ponderosa, Quercus rubra and Pseudotsuga menziesii.

    Science.gov (United States)

    Warren, Jeffrey M; Bassman, John H; Mattinson, D Scott; Fellman, John K; Edwards, Gerald E; Robberecht, Ronald

    2002-03-01

    Chromatographic analyses of foliage from several tree species illustrate the species-specific effects of UV-B radiation on both quantity and composition of foliar flavonoids. Pinus ponderosa, Quercus rubra and Pseudotsuga menziesii were field-grown under modulated ambient (1x) and enhanced (2x) biologically effective UV-B radiation. Foliage was harvested seasonally over a 3-year period, extracted, purified and the flavonoid fraction applied to a mu Bondapak/C(18) column HPLC system sampling at 254 nm. Total flavonoid concentrations in Quercus rubra foliage were more than twice (leaf area basis) that of the other species; Pseudotsuga menziesii foliage had intermediate levels and P. ponderosa had the lowest concentrations of total flavonoids. No statistically significant UV-B radiation-induced effects were found in total foliar flavonoid concentrations for any species; however, concentrations of specific compounds within each species exhibited significant treatment effects. Higher (but statistically insignificant) levels of flavonoids were induced by UV-B irradiation in 1- and 2-year-old P. ponderosa foliage. Total flavonoid concentrations in 2-year-old needles increased by 50% (1x ambient UV-B radiation) or 70% (2x ambient UV-B radiation) from that of 1-year-old tissue. Foliar flavonoids of Q. rubra under enhanced UV-B radiation tended to shift from early-eluting compounds to less polar flavonoids eluting later. There were no clear patterns of UV-B radiation effects on 1-year-old P. menziesii foliage. However, 2-year-old tissue had slightly higher foliar flavonoids under the 2x UV-B radiation treatment compared to ambient levels. Results suggest that enhanced UV-B radiation will alter foliar flavonoid composition and concentrations in forest tree species, which could impact tissue protection, and ultimately, competition, herbivory or litter decomposition.

  2. Using lidar and effective LAI data to evaluate IKONOS and Landsat 7 ETM+ vegetation cover estimates in a ponderosa pine forest

    Science.gov (United States)

    Chen, X.; Vierling, Lee; Rowell, E.; DeFelice, Tom

    2004-01-01

    Structural and functional analyses of ecosystems benefit when high accuracy vegetation coverages can be derived over large areas. In this study, we utilize IKONOS, Landsat 7 ETM+, and airborne scanning light detection and ranging (lidar) to quantify coniferous forest and understory grass coverages in a ponderosa pine (Pinus ponderosa) dominated ecosystem in the Black Hills of South Dakota. Linear spectral mixture analyses of IKONOS and ETM+ data were used to isolate spectral endmembers (bare soil, understory grass, and tree/shade) and calculate their subpixel fractional coverages. We then compared these endmember cover estimates to similar cover estimates derived from lidar data and field measures. The IKONOS-derived tree/shade fraction was significantly correlated with the field-measured canopy effective leaf area index (LAIe) (r2=0.55, pvegetation index (EVI) calculated from IKONOS imagery showed a negative correlation with the field measured tree canopy effective LAI and lidar tree cover response (r2=0.30, r=−0.55 and r2=0.41, r=−0.64, respectively; pvegetation fractions in this ecosystem than using normalized difference of vegetation index (NDVI). Coarsening the IKONOS data to 30 m resolution imagery revealed a stronger relationship with lidar tree measures (r2=0.77, p<0.001) than at 4 m resolution (r2=0.58, p<0.001). Unmixed tree/shade fractions derived from 30 m resolution ETM+ imagery also showed a significant correlation with the lidar data (r2=0.66, p<0.001). These results demonstrate the power of using high resolution lidar data to validate spectral unmixing results of satellite imagery, and indicate that IKONOS data and Landsat 7 ETM+ data both can serve to make the important distinction between tree/shade coverage and exposed understory grass coverage during peak summertime greenness in a ponderosa pine forest ecosystem.

  3. Observations and models of emissions of volatile terpenoid compounds from needles of ponderosa pine trees growing in situ: control by light, temperature and stomatal conductance.

    Science.gov (United States)

    Harley, Peter; Eller, Allyson; Guenther, Alex; Monson, Russell K

    2014-09-01

    Terpenoid emissions from ponderosa pine (Pinus ponderosa subsp. scopulorum) were measured in Colorado, USA over two growing seasons to evaluate the role of incident light, needle temperature, and stomatal conductance in controlling emissions of 2-methyl-3-buten-2-ol (MBO) and several monoterpenes. MBO was the dominant daylight terpenoid emission, comprising on average 87% of the total flux, and diurnal variations were largely determined by light and temperature. During daytime, oxygenated monoterpenes (especially linalool) comprised up to 75% of the total monoterpenoid flux from needles. A significant fraction of monoterpenoid emissions was dependent on light and 13CO2 labeling studies confirmed de novo production. Thus, modeling of monoterpenoid emissions required a hybrid model in which a significant fraction of emissions was dependent on both light and temperature, while the remainder was dependent on temperature alone. Experiments in which stomata were forced to close using abscisic acid demonstrated that MBO and a large fraction of the monoterpene flux, presumably linalool, could be limited at the scale of seconds to minutes by stomatal conductance. Using a previously published model of terpenoid emissions, which explicitly accounts for the physicochemical properties of emitted compounds, we were able to simulate these observed stomatal effects, whether induced experimentally or arising under naturally fluctuation conditions of temperature and light. This study shows unequivocally that, under naturally occurring field conditions, de novo light-dependent monoterpenes comprise a significant fraction of emissions in ponderosa pine. Differences between the monoterpene composition of ambient air and needle emissions imply a significant non-needle emission source enriched in Δ-3-carene.

  4. Estimating stand structure using discrete-return lidar: an example from low density, fire prone ponderosa pine forests

    Science.gov (United States)

    Hall, S. A.; Burke, I.C.; Box, D. O.; Kaufmann, M. R.; Stoker, Jason M.

    2005-01-01

    The ponderosa pine forests of the Colorado Front Range, USA, have historically been subjected to wildfires. Recent large burns have increased public interest in fire behavior and effects, and scientific interest in the carbon consequences of wildfires. Remote sensing techniques can provide spatially explicit estimates of stand structural characteristics. Some of these characteristics can be used as inputs to fire behavior models, increasing our understanding of the effect of fuels on fire behavior. Others provide estimates of carbon stocks, allowing us to quantify the carbon consequences of fire. Our objective was to use discrete-return lidar to estimate such variables, including stand height, total aboveground biomass, foliage biomass, basal area, tree density, canopy base height and canopy bulk density. We developed 39 metrics from the lidar data, and used them in limited combinations in regression models, which we fit to field estimates of the stand structural variables. We used an information–theoretic approach to select the best model for each variable, and to select the subset of lidar metrics with most predictive potential. Observed versus predicted values of stand structure variables were highly correlated, with r2 ranging from 57% to 87%. The most parsimonious linear models for the biomass structure variables, based on a restricted dataset, explained between 35% and 58% of the observed variability. Our results provide us with useful estimates of stand height, total aboveground biomass, foliage biomass and basal area. There is promise for using this sensor to estimate tree density, canopy base height and canopy bulk density, though more research is needed to generate robust relationships. We selected 14 lidar metrics that showed the most potential as predictors of stand structure. We suggest that the focus of future lidar studies should broaden to include low density forests, particularly systems where the vertical structure of the canopy is important

  5. Non-native plant invasions in managed and protected ponderosa pine/Douglas-fir forests of the Colorado Front Range

    Science.gov (United States)

    Fornwalt, P.J.; Kaufmann, M.R.; Huckaby, L.S.; Stoker, J.M.; Stohlgren, T.J.

    2003-01-01

    We examined patterns of non-native plant diversity in protected and managed ponderosa pine/Douglas-fir forests of the Colorado Front Range. Cheesman Lake, a protected landscape, and Turkey Creek, a managed landscape, appear to have had similar natural disturbance histories prior to European settlement and fire protection during the last century. However, Turkey Creek has experienced logging, grazing, prescribed burning, and recreation since the late 1800s, while Cheesman Lake has not. Using the modified-Whittaker plot design to sample understory species richness and cover, we collected data for 30 0.1 ha plots in each landscape. Topographic position greatly influenced results, while management history did not. At both Cheesman Lake and Turkey Creek, low/riparian plots had highest native and non-native species richness and cover; upland plots (especially east/west-facing, south-facing and flat, high plots) had the lowest. However, there were no significant differences between Cheesman Lake and Turkey Creek for native species richness, native species cover, non-native species richness, or non-native species cover for any topographic category. In general, non-native species richness and cover were highly positively correlated with native species richness and/or cover (among other variables). In total, 16 non-native species were recorded at Cheesman Lake and Turkey Creek; none of the 16 non-native species were more common at one site than another. These findings suggest that: (1) areas that are high in native species diversity also contain more non-native species; (2) both protected and managed areas can be invaded by non-native plant species, and at similar intensities; and (3) logging, grazing, and other similar disturbances may have less of an impact on non-native species establishment and growth than topographic position (i.e., in lowland and riparian zones versus upland zones).

  6. Thermotolerance and heat stress responses of Douglas-fir and ponderosa pine seedling populations from contrasting climates.

    Science.gov (United States)

    Marias, Danielle E; Meinzer, Frederick C; Woodruff, David R; McCulloh, Katherine A

    2016-12-21

    Temperature and the frequency and intensity of heat waves are predicted to increase throughout the 21st century. Germinant seedlings are expected to be particularly vulnerable to heat stress because they are in the boundary layer close to the soil surface where intense heating occurs in open habitats. We quantified leaf thermotolerance and whole-plant physiological responses to heat stress in first-year germinant seedlings in two populations each of Pinus ponderosa P. and C. Lawson (PIPO) and Pseudotsuga menziesii (Mirb.) Franco (PSME) from climates with contrasting precipitation and temperature regimes. Thermotolerance of detached needles was evaluated using chlorophyll fluorescence (FV/FM, FO) and electrolyte leakage. PSME was more heat tolerant than PIPO according to both independent assessments of thermotolerance. Following exposure of whole seedlings to a simulated heat wave at 45 °C for 1 h in a growth chamber, we monitored FV/FM, photosynthesis, stomatal conductance, non-structural carbohydrates (NSCs) and carbon isotope ratios (δ(13)C) for 14 days. Heat treatment induced significant reductions in FV/FM in both species and a transient reduction in photosynthetic gas exchange only in PIPO 1 day after treatment. Heat treatment induced an increase in glucose + fructose concurrent with a decrease in starch in both species, whereas total NSC and sucrose were not affected by heat treatment. The negative relationship between glucose + fructose and starch observed in treated plants may be due to the conversion of starch to glucose + fructose to aid recovery from heat-induced damage. Populations from drier sites displayed greater δ(13)C values than those from wetter sites, consistent with higher intrinsic water-use efficiency and drought resistance of populations from drier climates. Thermotolerance and heat stress responses appeared to be phenotypically plastic and representative of the environment in which plants were grown, whereas intrinsic water

  7. Satellite Image-based Estimates of Snow Water Equivalence in Restored Ponderosa Pine Forests in Northern Arizona

    Science.gov (United States)

    Sankey, T.; Springer, A. E.; O'Donnell, F. C.; Donald, J.; McVay, J.; Masek Lopez, S.

    2014-12-01

    The U.S. Forest Service plans to conduct forest restoration treatments through the Four Forest Restoration Initiative (4FRI) on hundreds of thousands of acres of ponderosa pine forest in northern Arizona over the next 20 years with the goals of reducing wildfire hazard and improving forest health. The 4FRI's key objective is to thin and burn the forests to create within-stand openings that "promote snowpack accumulation and retention which benefit groundwater recharge and watershed processes at the fine (1 to 10 acres) scale". However, little is known about how these openings created by restoration treatments affect snow water equivalence (SWE) and soil moisture, which are key parts of the water balance that greatly influence water availability for healthy trees and for downstream water users in the Sonoran Desert. We have examined forest canopy cover by calculating a Normalized Difference Vegetation Index (NDVI), a key indicator of green vegetation cover, using Landsat satellite data. We have then compared NDVI between treatments at our study sites in northern Arizona and have found statistically significant differences in tree canopy cover between treatments. The control units have significantly greater forest canopy cover than the treated units. The thinned units also have significantly greater tree canopy cover than the thin-and-burn units. Winter season Landsat images have also been analyzed to calculate Normalized Difference Snow Index (NDSI), a key indicator of snow water equivalence and snow accumulation at the treated and untreated forests. The NDSI values from these dates are examined to determine if snow accumulation and snow water equivalence vary between treatments at our study sites. NDSI is significantly greater at the treated units than the control units. In particular, the thinned forest units have significantly greater snow cover than the control units. Our results indicate that forest restoration treatments result in increased snow pack

  8. Emissions and ambient distributions of Biogenic Volatile Organic Compounds (BVOC in a Ponderosa pine ecosystem: interpretation of PTR-MS mass spectra

    Directory of Open Access Journals (Sweden)

    S. Kim

    2009-10-01

    Full Text Available Two proton-transfer-reaction mass spectrometry systems were deployed at the Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen-Southern Rocky Mountain 2008 field campaign (BEACHON-SRM08; July to September 2008 at the Manitou Forest observatory in a Ponderosa pine woodland near Woodland Park, Colorado USA to simultaneously measure BVOC emissions and ambient distributions of their oxidation products. Here, we present mass spectral analysis in a wide range of masses (m/z=40+ to 210+ to assess our understanding of BVOC emissions and their photochemical process inside of the forest canopy. The biogenic terpenoids, 2-methyl-3-butene-2-ol (MBO, 50.2% and several monoterpenes (MT, 33.5% were identified as the dominant BVOC emissions from a transmission corrected mass spectrum, averaged over the daytime (11 am to 3 p.m., local time of three days. To assess contributions of oxidation products of local BVOC, we calculate a oxidation product spectrum with the OH- and ozone-initiated oxidation product distribution mass spectra of two major BVOC at the ecosystem (MBO and β-pinene that were observed from laboratory oxidation experiments. A majority (~73% of the total signal could be explained by known compounds. The remainder are attributed to oxidation products of BVOC, emitted from nearby ecosystems and transported to the site, and oxidation products of unidentified BVOC emitted from the Ponderosa pine ecosystem.

  9. Electronics and electronic systems

    CERN Document Server

    Olsen, George H

    1987-01-01

    Electronics and Electronic Systems explores the significant developments in the field of electronics and electronic devices. This book is organized into three parts encompassing 11 chapters that discuss the fundamental circuit theory and the principles of analog and digital electronics. This book deals first with the passive components of electronic systems, such as resistors, capacitors, and inductors. These topics are followed by a discussion on the analysis of electronic circuits, which involves three ways, namely, the actual circuit, graphical techniques, and rule of thumb. The remaining p

  10. STUDIES ON THE MORPHOLOGICAL CHARACTERS AND BIONOMICS OF DENDROCTONUS VALENS LECONTE%红脂大小蠹形态学特征及生物学特性研究

    Institute of Scientific and Technical Information of China (English)

    张历燕; 陈庆昌; 张小波

    2002-01-01

    红脂大小蠹又名强大小蠹(Dendroctonus valens LeConte),为国内新纪录种,是油松(Pinus tabulaeformis Carr.)的毁灭性害虫,可导致几十年生的油松在较短期内死亡.越冬虫态以成虫和老熟幼虫为主,占77.5%,2~3龄幼虫为辅,占21.7 %,少数以蛹越冬,占0.8%.其生活史以成虫越冬的1a 1代,以老熟幼虫越冬的需跨年度才能完成1个世代发育,以小幼虫越冬的需3a完成2代或2a完成1代.在种群密度较低时,危害生长衰弱的过火木、新伐倒木及新的伐桩,种群密度大时,能迅速入侵胸径≥10cm、树龄在20a生以上的健康木.在郁闭度较低的油松林分中,红脂大小蠹的危害明显高于郁闭度高的林分.

  11. 华山松大小蠹带菌部位及贮菌器结构研究%THE MYCANGIUM POSITION AND STRUCTURE OF THE BARK BEETLE DENDROCTONUS ARMANDI

    Institute of Scientific and Technical Information of China (English)

    陈辉; 袁锋

    2000-01-01

    研究了秦岭林区华山松大小蠹(Dendroctonus armandi)带菌部位及贮菌器结构,结果表明:华山松大小蠹成虫具有前胸背板体壁凹陷和刺毛构成的贮菌器,用于携带和传播真菌,其所携带真菌种类以穿孔细帚霉Leptographium terebrantis和小线嘴壳Ophiostoma minus为主,以真菌孢子为唯一携带方式,并在成虫入侵健康寄主华山松时将携带真菌孢子接种于华山松木质部.华山松大小蠹消化道内不具有含菌细胞和特化的带菌结构,消化道内存在的真菌也没有菌丝发育形成的附着孢或吸盘结构,使真菌不能被有效地贮存或携带于华山松大小蠹成虫消化道内,从而达到对真菌的有效传播和导致华山松大小蠹与真菌共生的联系.

  12. 马栏林区红脂大小蠹及天敌昆虫诱捕效果研究%Trapping Effects of Dendroctonus valens and Its Natural Enemies

    Institute of Scientific and Technical Information of China (English)

    张中社; 赵俊侠; 乔宽

    2015-01-01

    对陕西省旬邑县马栏林场8个林区小班红脂大小蠹(Dendroctonus valens)进行诱捕及数据分析,对每个诱捕器内红脂大小蠹的平均变化数进行了数学模拟回归,并建立了数学模型.结果表明,红脂大小蠹成虫及天敌昆虫的发生均呈“S”变化,其最高日出虫时期在6月上旬.“S”形变化曲线具体分为缓慢增加期(3月下旬-4月下旬)、快速增加期(5月上旬-5月下旬)、快速减少期(6月上旬-6月下旬)和缓慢减少期(7月上旬-7月下旬)4个阶段;红脂大小蠹雌虫总数以及日出虫数均高于雄虫,且高峰期早出现2d左右.成虫总数也高于天敌昆虫数量,高峰期早出现2d.

  13. Influence of Slope and Aspect on Dendroctonus valens LeConte Occurrence%坡向与坡度对红脂大小蠹发生的影响

    Institute of Scientific and Technical Information of China (English)

    高浩洁

    2012-01-01

    The influence of slope and aspect on Dendroctonus valens LeConte occurrence were studied. The results showed that, in terms of aspect, the top peak of slope suffered heaviest damage with the damage rate reaching 40. 89%. Regarding slope, the damage rate reached 17.79% and 14. 98% respectively on gentle slope and steep slope, indicating gentle slope suffers less damage than steep slope.%对红脂大小蠹的发生与坡度及坡向的关系进行了研究。结果表明,对于不同坡向来说,山顶受害程度最重,被害率达到了40.89%;而对于不同坡度来说,红脂大小蠹的危害差异显著,缓坡和陡坡的被害率分别达到了17.79%和14.98%,缓坡危害程度大于陡坡。

  14. Distribution and Optimal Sampling Model of Larval Dendroctonus armandi%华山松大小蠹幼虫分布状态及最佳抽样模型

    Institute of Scientific and Technical Information of China (English)

    赵利敏; 陈锐; 何杰

    2008-01-01

    在陕西省留坝县的华山松(Pinus armandi)林区,对华山松大小蠹(Dendroctonus arman-di)种群密度、分布状态和抽样模型进行了研究.结果表明:华山松大小蠹幼虫密度在华山松树干1~10 m高度范围内各不相等;危害致死华山松成年树的华山松大小蠹种群密度为23.2~52.8头·dm-2,平均37.4头·dm-2;平均值与树干4 m高处样方虫数均值接近;华山松大小蠹幼虫在树干上集中分布于树干7~8 m高处.

  15. Differentiation of CO Ⅰ gene of the exotic red turpentine beetle Dendroctonus valens%外来入侵种红脂大小蠹COⅠ基因分化的研究

    Institute of Scientific and Technical Information of China (English)

    姚剑; 温劲松; 张龙娃; 李云飞; 陈雪娇; 余晓峰

    2010-01-01

    红脂大小蠹Dendroctonus valens LeConte为近年来危害最为严重的外来入侵生物.本研究利用特异引物扩增出红脂大小蠹CO Ⅰ基因序列(GenBank登录号:GQ495096-GQ495128),在160个位点中发现3个该种与大小蠹属其他种不同的特异位点;比较不同地理种群的红脂大小蠹,发现中国种群间遗传分化不明显,说明入侵种的瓶颈效应,而遗传变异是入侵种与环境长期互作的结果;基于CO Ⅰ基因序列比对的研究发现,入侵中国的红脂大小蠹与该虫原发生地北美洲部分种群具有同源性.

  16. 拟双角斯氏线虫侵染红脂大小蠹幼虫的研究%INFECTIVITY OF ENTOMOPATHGENIC NEMATODE STEINERNEMA CERATOPHORUM TO BARK BEETLE DENDROCTONUS VALENS LARVAE

    Institute of Scientific and Technical Information of China (English)

    简恒; 杨秀芬; 刘峥; 杨怀文; 苗振旺

    2002-01-01

    @@ 红脂大小蠹又名强大小蠹(Dendroctonus valens LeConte) 主要危害30a以上或胸径10cm以上的健康油松.成虫一般在树干基部至1m左右处入侵,入侵后先向上蛀食一段韧皮部,然后向下取食,危害可达根部40cm.每头雌成虫可产卵110余粒,幼虫孵化后继续蛀食韧皮部,形成共同虫道.虫道环树干一周切断形成层,造成树木死亡.该虫具有繁殖快、成灾快、传播快、致死快的"四快"特点,其危害严重性不亚于松材线虫.

  17. 大小蠹植物引诱剂对红脂大小蠹诱引效果试验%Inducing Experiment of Attractants to Dendroctonus valens LeConte

    Institute of Scientific and Technical Information of China (English)

    苗振旺; 赵明梅; 芦学林

    2002-01-01

    2000年至2001年,在山西省榆次区庆城林场应用加拿大生产的大小蠹类植物引诱荆对红脂大小蠹(Dendroctonus valens LeConte)成虫发生期进行了监测,并开展了大量诱杀试验。结果表明,该引诱剂对红脂大小蠹成虫有较强的引诱作用,60个诱捕器在成虫扬飞期共诱到大小蠹成虫7119头。应用诱捕器后,林地红脂大小蠹被害率下降54.5%,平均侵入孔数下降58.7%。可用于红脂大小蠹的监测和防治。

  18. Spatial and temporal corroboration of a fire-scar-based fire history in a frequently burned ponderosa pine forest.

    Science.gov (United States)

    Farris, Calvin A; Baisan, Christopher H; Falk, Donald A; Yool, Stephen R; Swetnam, Thomas W

    2010-09-01

    Fire scars are used widely to reconstruct historical fire regime parameters in forests around the world. Because fire scars provide incomplete records of past fire occurrence at discrete points in space, inferences must be made to reconstruct fire frequency and extent across landscapes using spatial networks of fire-scar samples. Assessing the relative accuracy of fire-scar fire history reconstructions has been hampered due to a lack of empirical comparisons with independent fire history data sources. We carried out such a comparison in a 2780-ha ponderosa pine forest on Mica Mountain in southern Arizona (USA) for the time period 1937-2000. Using documentary records of fire perimeter maps and ignition locations, we compared reconstructions of key spatial and temporal fire regime parameters developed from documentary fire maps and independently collected fire-scar data (n = 60 plots). We found that fire-scar data provided spatially representative and complete inventories of all major fire years (> 100 ha) in the study area but failed to detect most small fires. There was a strong linear relationship between the percentage of samples recording fire scars in a given year (i.e., fire-scar synchrony) and total area burned for that year (y = 0.0003x + 0.0087, r2 = 0.96). There was also strong spatial coherence between cumulative fire frequency maps interpolated from fire-scar data and ground-mapped fire perimeters. Widely reported fire frequency summary statistics varied little between fire history data sets: fire-scar natural fire rotations (NFR) differed by fire return intervals (MFI) for large-fire years (i.e., > or = 25% of study area burned) were identical between data sets (25.5 yr); fire-scar MFIs for all fire years differed by 1.2 yr from documentary records. The known seasonal timing of past fires based on documentary records was furthermore reconstructed accurately by observing intra-annual ring position of fire scars and using knowledge of tree-ring growth

  19. Undisturbed and disturbed above canopy ponderosa pine emissions: PTR-TOF-MS measurements and MEGAN 2.1 model results

    Science.gov (United States)

    Kaser, L.; Karl, T.; Guenther, A.; Graus, M.; Schnitzhofer, R.; Turnipseed, A.; Fischer, L.; Harley, P.; Madronich, M.; Gochis, D.; Keutsch, F. N.; Hansel, A.

    2013-12-01

    We present the first eddy covariance flux measurements of volatile organic compounds (VOCs) using a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) above a ponderosa pine forest in Colorado, USA. The high mass resolution of the PTR-TOF-MS enabled the identification of chemical sum formulas. During a 30 day measurement period in August and September 2010, 649 different ion mass peaks were detected in the ambient air mass spectrum (including primary ions and mass calibration compounds). Eddy covariance with the vertical wind speed was calculated for all ion mass peaks. On a typical day, 17 ion mass peaks, including protonated parent compounds, their fragments and isotopes as well as VOC-H+-water clusters, showed a significant flux with daytime average emissions above a reliable flux threshold of 0.1 mg compound m-2 h-1. These ion mass peaks could be assigned to seven compound classes. The main flux contributions during daytime (10:00-18:00 LT) are attributed to the sum of 2-methyl-3-buten-2-ol (MBO) and isoprene (50%), methanol (12%), the sum of acetic acid and glycolaldehyde (10%) and the sum of monoterpenes (10%). The total MBO + isoprene flux was composed of 10% isoprene and 90% MBO. There was good agreement between the light- and temperature dependency of the sum of MBO and isoprene observed for this work and those of earlier studies. The above canopy flux measurements of the sum of MBO and isoprene and the sum of monoterpenes were compared to emissions calculated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN 2.1). The best agreement between MEGAN 2.1 and measurements was reached using emission factors determined from site-specific leaf cuvette measurements. While the modeled and measured MBO + isoprene fluxes agree well, the emissions of the sum of monoterpenes is underestimated by MEGAN 2.1. This is expected as some factors impacting monoterpene emissions, such as physical damage of needles and branches due to

  20. Undisturbed and disturbed above canopy ponderosa pine emissions: PTR-TOF-MS measurements and MEGAN 2.1 model results

    Directory of Open Access Journals (Sweden)

    L. Kaser

    2013-06-01

    Full Text Available We present the first eddy covariance flux measurements of volatile organic compounds (VOCs using a proton-transfer-reaction time-of-flight mass-spectrometer (PTR-TOF-MS above a ponderosa pine forest in Colorado, USA. The high mass resolution of the PTR-TOF-MS enabled the identification of chemical sum formulas. During a 30 day measurement period in August and September 2010, 649 different ion mass peaks were detected in the ambient air mass spectrum (including primary ions and mass calibration compounds. Eddy covariance with the vertical wind speed was calculated for all ion mass peaks. On a typical day, 17 ion mass peaks including protonated parent compounds, their fragments and isotopes as well as VOC-H+-water clusters showed a significant flux with daytime average emissions above a reliable flux threshold of 0.1 mg compound m−2 h−1. These ion mass peaks could be assigned to seven compound classes. The main flux contributions during daytime (10:00–18:00 LT are attributed to the sum of 2-methyl-3-buten-2-ol (MBO and isoprene (50%, methanol (12%, the sum of acetic acid and glycolaldehyde (10% and the sum of monoterpenes (10%. The total MBO + isoprene flux was composed of 10% isoprene and 90% MBO. There was good agreement between the light and temperature dependency of the sum of MBO and isoprene observed for this work and those of earlier studies. The above canopy flux measurements of the sum of MBO and isoprene and the sum of monoterpenes were compared to emissions calculated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN 2.1. The best agreement between MEGAN 2.1 and measurements was reached using emission factors determined from site specific leaf cuvette measurements. While the modelled and measured MBO + isoprene fluxes agree well the emissions of the sum of monoterpenes is underestimated by MEGAN 2.1. This is expected as some factors impacting monoterpene emissions, such as physical damage of needles and

  1. Undisturbed and disturbed above canopy ponderosa pine emissions: PTR-TOF-MS measurements and MEGAN 2.1 model results

    Energy Technology Data Exchange (ETDEWEB)

    Kaser, L.; Karl, T.; Guenther, A.; Graus, M.; Schnitzhofer, R.; Turnipseed, A.; Fischer, L.; Harley, P.; Madronich, M.; Gochis, D.; Keutsch, F. N.; Hansel, A.

    2013-01-01

    We present the first eddy covariance flux measurements of volatile organic compounds (VOCs) using a proton-transfer-reaction time-of-flight mass-spectrometer (PTR-TOFMS) above a ponderosa pine forest in Colorado, USA. The high mass resolution of the PTR-TOF-MS enabled the identification of chemical sum formulas. During a 30 day measurement period in August and September 2010, 649 different ion mass peaks were detected in the ambient air mass spectrum (including primary ions and mass calibration ompounds). Eddy covariance with the vertical wind speed was calculated for all ion mass peaks. On a typical day, 17 ion mass peaks including protonated parent compounds, their fragments and isotopes as well as VOC-H+-water clusters showed a significant flux with daytime average emissions above a reliable flux threshold of 0.1mgcompoundm-2 h-1. These ion mass peaks could be assigned to seven compound classes. The main flux contributions during daytime (10:00-18:00 LT) are attributed to the sum of 2-methyl-3-buten-2-ol (MBO) and isoprene (50 %), methanol (12%), the sum of acetic acid and glycolaldehyde (10%) and the sum of monoterpenes (10 %). The total MBO+isoprene flux was composed of 10% isoprene and 90% MBO. There was good agreement between the light and temperature dependency of the sum of MBO and isoprene observed for this work and those of earlier studies. The above canopy flux measurements of the sum of MBO and isoprene and the sum of 20 monoterpenes were compared to emissions calculated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN 2.1). The best agreement between MEGAN 2.1 and measurements was reached using emission factors determined from site specific leaf cuvette measurements. While the modelled and measured MBO+isoprene fluxes agree well the emissions of the sum of monoterpenes is underestimated by MEGAN 2.1. This is expected as some factors impacting monoterpene emissions, such as physical damage of needles and branches due to storms, are

  2. Metasystox-R, applied in mauget injectors, ineffective in protecting individual ponderosa pines from western pine beetles. Forest Service research note

    Energy Technology Data Exchange (ETDEWEB)

    Haverty, M.I.; Shea, P.J.; Wenz, J.M.

    1996-12-31

    The effectiveness of registered application rates of the insecticide metasystox-R applied with Mauget tree injectors (INJECT-A-CIDE) was assessed in two strategies: (1) treatment of trees before western pine beetle attack (preventive treatment), and (2) treatment of trees after attack by western pine beetle (remedial treatment) for protection of individual, high-value ponderosa pine. This field test was conducted on the western slope of the Sierra Nevada on the Eldorado National Forest in central California by using three treatments: metasystox-R injected about 14 days before the onset of beetle attack; metasystox-R injected about 7 days after the onset of beetle attack; and an untreated check.

  3. Emissions and ambient distributions of Biogenic Volatile Organic Compounds (BVOC in a ponderosa pine ecosystem: interpretation of PTR-MS mass spectra

    Directory of Open Access Journals (Sweden)

    S. Kim

    2010-02-01

    Full Text Available Two proton-transfer-reaction mass spectrometry systems were deployed at the Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen-Southern Rocky Mountain 2008 field campaign (BEACHON-SRM08; July to September, 2008 at the Manitou Forest Observatory in a ponderosa pine woodland near Woodland Park, Colorado USA. The two PTR-MS systems simultaneously measured BVOC emissions and ambient distributions of their oxidation products. Here, we present mass spectral analysis in a wide range of masses (m/z 40+ to 210+ to assess our understanding of BVOC emissions and their photochemical processing inside of the forest canopy. The biogenic terpenoids, 2-methyl-3-butene-2-ol (MBO, 50.2% and several monoterpenes (MT, 33.5% were identified as the dominant BVOC emissions from a transmission corrected mass spectrum (PTR-MS, averaged over the daytime (11 a.m. to 3 p.m., local time of three days. To assess contributions of oxidation products of local BVOC, we calculate an oxidation product spectrum with the OH- and ozone-initiated oxidation product distribution mass spectra of two major BVOC emissions at the ecosystem (MBO and β-pinene that were observed from laboratory oxidation experiments. The majority (~76% of the total signal in the transmission corrected PTR-MS spectra could be explained by identified compounds. The remainder are attributed to oxidation products of BVOC emitted from nearby ecosystems and transported to the site, and oxidation products of unidentified BVOC emitted from the ponderosa pine ecosystem.

  4. Observations and models of emissions of volatile terpenoid compounds from needles of ponderosa pine trees growing in situ: control by light, temperature and stomatal conductance

    Energy Technology Data Exchange (ETDEWEB)

    Harley, Peter; Eller, Allyson; Guenther, Alex; Monson, Russell K.

    2014-07-12

    Terpenoid emissions from ponderosa pine (Pinus ponderosa subsp. scopulorum) were measured in Colorado, USA over two growing seasons to evaluate the role of incident light, needle temperature and stomatal conductance in controlling emissions of 2-methyl-3-buten-2-ol (MBO) and several monoterpenes. MBO was the dominant daylight terpenoid emission, comprising on average 87% of the total flux, and diurnal variations were largely determined by light and temperature. During daytime, oxygenated monoterpenes (especially linalool) comprised up to 75% of the total monoterpenoid flux from needles. A significant fraction of monoterpenoid emissions was light dependent and 13CO2 labeling studies confirmed de novo production. Thus, modeling of monoterpenoid emissions required a hybrid model in which a significant fraction of emissions was dependent on both light and temperature, while the remainder was dependent on temperature alone. Experiments in which stomata were forced to close using abscisic acid demonstrated that MBO and a large fraction of the monoterpene flux, presumably linalool, could be limited at the scale of seconds to minutes by stomatal conductance. Using a previously published model of terpenoid emissions which explicitly accounts for the physico-chemical properties of emitted compounds, we are able to simulate these observed stomatal effects, whether induced through experimentation or arising under naturally fluctuation conditions of temperature and light. This study shows unequivocally that, under naturally occurring field conditions, de novo light dependent monoterpenes can comprise a large fraction of emissions. Differences between the monoterpene composition of ambient air and needle emissions imply a significant non-needle emission source enriched in Δ-3-carene.

  5. Effects of branch height on leaf gas exchange, branch hydraulic conductance and branch sap flux in open-grown ponderosa pine.

    Science.gov (United States)

    Hubbard, Robert M; Bond, Barbara J; Senock, Randy S; Ryan, Michael G

    2002-06-01

    Recent studies have shown that stomata respond to changes in hydraulic conductance of the flow path from soil to leaf. In open-grown tall trees, branches of different heights may have different hydraulic conductances because of differences in path length and growth. We determined if leaf gas exchange, branch sap flux, leaf specific hydraulic conductance, foliar carbon isotope composition (delta13C) and ratios of leaf area to sapwood area within branches were dependent on branch height (10 and 25 m) within the crowns of four open-grown ponderosa pine (Pinus ponderosa Laws.) trees. We found no difference in leaf gas exchange or leaf specific hydraulic conductance from soil to leaf between the upper and lower canopy of our study trees. Branch sap flux per unit leaf area and per unit sapwood area did not differ between the 10- and 25-m canopy positions; however, branch sap flux per unit sapwood area at the 25-m position had consistently lower values. Branches at the 25-m canopy position had lower leaf to sapwood area ratios (0.17 m2 cm-2) compared with branches at the 10-m position (0.27 m2 cm-2) (P = 0.03). Leaf specific conductance of branches in the upper crown did not differ from that in the lower crown. Other studies at our site indicate lower hydraulic conductance, sap flux, whole-tree canopy conductance and photosynthesis in old trees compared with young trees. This study suggests that height alone may not explain these differences.

  6. Shallow geothermal investigations into the existence of the Valles Caldera outflow plume near Ponderosa and Jemez Pueblo, north-central, New Mexico

    Science.gov (United States)

    Salaz, Robert Ezekiel

    Geothermal research within the Jemez Mountains spans several decades and is documented in many papers. This study serves to extend the research boundary to the south and east outside of Valles caldera and Canon de San Diego, where the main occurrences of geothermal activity are located. The focus of this investigation is to test for a deep ~900 m, stratigraphically-bound thermal aquifer within the Madera Limestone along the western margin of the Santo Domingo basin transition zone near Ponderosa and Jemez Pueblo, in north-central New Mexico. Numerous springs were sampled for aqueous geochemistry to identify leakage of a deeper geothermal aquifer into shallow aquifers. Wells were sampled for temperature anomalies. In addition, two travertine deposits were analyzed for stable isotope composition and one deposit was dated using U-Series techniques to assess the timing and origin of deposition. This study is important because researchers in other extensional basins have identified reasonably good geothermal reservoirs in deep carbonate aquifers that are similar in geologic setting to the Madera Limestone aquifer of this study. The existence of a deep geothermal aquifer near Ponderosa and Jemez Pueblo, New Mexico could prove to be another prospect for geothermal exploration in the Jemez Mountains. Aqueous geochemistry of springs are plotted on ternary Piper diagrams to help classify similar geochemical trends and group these trends into recognizable patterns. These data indicate calcium carbonate rich waters in the north that may gradationally change to alkaline type waters as they flow south through the study area. Contrasting this data, SiO2 and TDS concentrations show two separate systems that may indicate separate confined aquifers. Two distinct TDS regions are observed, one with higher concentrations (>1000 ppm) shows a decrease from N-S and one with lower concentrations (ProQuest.).

  7. Evaluación genética en etapa de vivero de áreas productoras de semillas (APS de Pino Ponderosa en Nordpatagonia

    Directory of Open Access Journals (Sweden)

    SCHINELLI, T.1;

    2012-08-01

    Full Text Available El Pino Ponderosa (Pinus ponderosa Dougl. ex Laws es la principal especie forestal implantada en secanoen la Patagonia. Su potencialidad productiva y la disponibilidad de tierras para su cultivo permiten proyectarla continuidad de su uso en plantaciones comerciales, para lo que es indispensable asegurar la provisión desemillas de adecuada calidad genética. Las semillas utilizadas en la última década se produjeron en una seriede rodales mediante ensayos para evaluar su descendencia. El objetivo del presente trabajo es evaluar estosrodales ensayando su descendencia. En este primer reporte presentamos los resultados de una evaluaciónen etapa de vivero. Se ensayaron 31 procedencias locales seleccionadas (Áreas Productoras de Semillas,APS en dos sitios, midiendo altura y diámetro a la altura del cuello en plantines de 2 años de edad. A través de análisis de la varianza se probó un claro efecto de interacción entre las APS y los sitios, y también diferencias entre las APS dentro de cada sitio. Seguidamente, se establecieron rankings de las APS por sitio y variable evaluada. A través de comparaciones de a pares se formaron grupos homogéneos. También se estimó la estabilidad genotípica de las APS por medio del cálculo de sus ecovalencias. Los resultados son aún preliminares, pero el haber probado diferencias en tan temprana edad nos alerta sobre la importancia de la procedencia de las semillas a utilizar para la producción comercial. Se espera que estas diferencias se acentúen en edades más avanzadas. Para probarlo, ya se han establecido ensayos de plantación.

  8. Adaptability to climate change in forestry species: drought effects on growth and wood anatomy of ponderosa pines growing at different competition levels

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, M. E.; Gyenge, J. E.; Urquiza, M. M.; Varela, S.

    2012-11-01

    More stressful conditions are expected due to climatic change in several regions, including Patagonia, South-America. In this region, there are no studies about the impact of severe drought events on growth and wood characteristics of the most planted forestry species, Pinus ponderosa (Doug. ex-Laws). The objective of this study was to quantify the effect of a severe drought event on annual stem growth and functional wood anatomy of pines growing at different plantation densities aiming to understand how management practices can help to increase their adaptability to climate change. Growth magnitude and period, specific hydraulic conductivity, and anatomical traits (early- and late wood proportion, lumen diameter, cell-wall thickness, tracheid length and bordered pit dimensions) were measured in the ring 2008-2009, which was formed during drought conditions. This drought event decreased annual stem growth by 30-38% and 58-65% respect to previous mean growth, in open vs. closed stand trees, respectively, indicating a higher sensitivity of the latter, which is opposite to reports from the same species growing in managed native forests in USA. Some wood anatomical variables did differ in more water stressed trees (lower cell wall thickness of early wood cells and higher proportion of small-lumen cells in late wood), which in turn did not affect wood function (hydraulic conductivity and resistance to implosion). Other anatomical variables (tracheid length, pit dimensions, early- and late wood proportion, lumen diameter of early wood cells) did not differ between tree sizes and plantation density. The results suggest that severe drought affects differentially the amount but not the function and quality of formed wood in ponderosa pine growing at different competition levels. (Author) 41 refs.

  9. 华山松大小蠹对几种寄主挥发物组分的EAG和行为反应%Electroantennographic and behavioral responses of Dendroctonus armandi(Coleoptera:Ipidae)to host plant volatiles

    Institute of Scientific and Technical Information of China (English)

    王茹琳; 杨伟; 杨佐忠; 陈小平; 杨春平; 李强; 李锋; 陈春茂

    2011-01-01

    为筛选适宜配制华山松大小蠹(Dendroctonus armandi)引诱剂的有效化学成分,用触角电位仪和Y型嗅觉仪测定了华山松大小蠹雌、雄虫对华山松挥发物主要成分的触角电生理(EAG)和行为反应.结果表明:在0.01、0.1、1、10、100 μg 5种刺激剂量下,7种化合物在特定浓度下均有明确的EAG反应;雌、雄虫对月桂烯、(+)-3-蒈烯、β-石竹烯3种化合物及雄虫对(+)-α-蒎烯、柠檬烯的EAG相对电位的最大值均出现在10μg刺激条件下;在10 μg刺激剂量条件下,雌虫对(+)-α-蒎烯、β-蒎烯和(+)-3-蒈烯有明显的正趋向反应,正趋向率均高于72%且显著高于雄成虫对3种挥发物的正趋向率;在1 μg刺激下,只有雄虫对(+)-3-蒈烯有一定正趋向反应;而在100μg条件下,(-)-α-蒎烯对雌、雄虫均有一定驱避作用.该研究结果可为开发华山松大小蠹林间引诱剂提供借鉴.%In order to screen attractive chemicals for trapping male and female Dendroctonus armandi, electroantennography and Y-tube olfactometer were used to test the electroantennographic ( EAG) and behavioral responses of D. armandi adults to the main components of the volatiles from Pinus armandii. At the dosages 0. 01, 0. 1, 1, 10, and 100 μg, seven test chemicals at their proper dosages all induced clear EAG responses. At the dosage 10 μg, myrcene, (+) -3- carene, and β-caryophyllene all elicited the highest EAG values to both the female and the male D. armandi adults, and (+) -α-pinene and limonene elicited the highest EAG values to the male D. armandi adults. Also at the dosage 10 μg, ( +) -α-pinene, β-pinene , and ( +) -3 -carene induced an obvious correct taxis response of the females, with the correct response percentages of the females being significantly higher ( >72% ) than those of the males. At the dosage 1 μg, only (+) -3-carene was attractive to the males. At the dosage 100 μg, ( -) -α-pinene had definite repellent

  10. Evaluation on control effect of parasitoids on Dendroctonus armandi population%寄生性天敌对华山松大小蠹种群控制作用评价

    Institute of Scientific and Technical Information of China (English)

    李菊; 谢寿安; 吕淑杰; 丁彦; 巩雪峰; 徐生福

    2009-01-01

    对秦岭林区优势先锋虫种华山松大小蠹 Dendroctonus armandi 寄生蜂种群的林问分布规律进行了研究.在标准地调查基础上,选择华山松大小蠹虫害木作为解析木,分期分批采集华山松大小蠹幼虫和蛹进行室内饲养.结果表明:秦岭林区华山松大小蠹有寄生蜂7种.在河谷地带华山松林中寄生蜂种类最多,7种寄生蜂都有分布,总寄生率最高(37.5%~42.5%),其它依次为竹子华山松林、鹿蹄草华山松林、苔草华山松林、山坡下部华山松林;华山松虫害木树干不同部位寄生蜂种群组成和总寄生率不同,华山松大小蠹寄生蜂种群在华山松虫害木树干上的垂直分布与华山松大小蠹种群相吻合,说明华山松大小蠹种群和寄生蜂种群长期以来建立了相互制约而又相互依存的密切关系.

  11. Using tree recruitment patterns and fire history to guide restoration of an unlogged ponderosa pine/Douglas-fir landscape in the southern Rocky Mountains after a century of fire suppression

    Science.gov (United States)

    Kaufmann, M.R.; Huckaby, L.S.; Fornwalt, P.J.; Stoker, J.M.; Romme, W.H.

    2003-01-01

    Tree age and fire history were studied in an unlogged ponderosa pine/Douglas-fir (Pinus ponderosa/Pseudotsuga menziesii) landscape in the Colorado Front Range mountains. These data were analysed to understand tree survival during fire and post-fire recruitment patterns after fire, as a basis for understanding the characteristics of, and restoration needs for, an ecologically sustainable landscape. Comparisons of two independent tree age data sets indicated that sampling what subjectively appear to be the five oldest trees in a forest polygon could identify the oldest tree. Comparisons of the ages of the oldest trees in each data set with maps of fire history suggested that delays in establishment of trees, after stand-replacing fire, ranged from a few years to more than a century. These data indicate that variable fire severity, including patches of stand replacement, and variable temporal patterns of tree recruitment into openings after fire were major causes of spatial heterogeneity of patch structure in the landscape. These effects suggest that restoring current dense and homogeneous ponderosa pine forests to an ecologically sustainable and dynamic condition should reflect the roles of fires and variable patterns of tree recruitment in regulating landscape structure.

  12. Mountain Pine Beetles Colonizing Historical and Naïve Host Trees Are Associated with a Bacterial Community Highly Enriched in Genes Contributing to Terpene Metabolism

    OpenAIRE

    Adams, Aaron S; Aylward, Frank O.; Adams, Sandye M; Erbilgin, Nadir; Aukema, Brian H.; Currie, Cameron R; Suen, Garret; Raffa, Kenneth F.

    2013-01-01

    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...

  13. Hard electronics; Hard electronics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    In the fields of power conversion devices and broadcasting/communication amplifiers, high power, high frequency and low losses are desirable. Further, for electronic elements in aerospace/aeronautical/geothermal surveys, etc., heat resistance to 500degC is required. Devices which respond to such hard specifications are called hard electronic devices. However, with Si which is at the core of the present electronics, the specifications cannot fully be fulfilled because of the restrictions arising from physical values. Accordingly, taking up new device materials/structures necessary to construct hard electronics, technologies to develop these to a level of IC were examined and studied. They are a technology to make devices/IC of new semiconductors such as SiC, diamond, etc. which can handle higher temperature, higher power and higher frequency than Si and also is possible of reducing losses, a technology to make devices of hard semiconducter materials such as a vacuum microelectronics technology using ultra-micro/high-luminance electronic emitter using negative electron affinity which diamond, etc. have, a technology to make devices of oxides which have various electric properties, etc. 321 refs., 194 figs., 8 tabs.

  14. Electronic Cigarettes

    Science.gov (United States)

    ... New FDA Regulations Text Size: A A A Electronic Cigarettes Electronic cigarettes (e-cigarettes) are battery operated products designed ... more about: The latest news and events about electronic cigarettes on this FDA page Electronic cigarette basics ...

  15. The Electron

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, George

    1972-01-01

    Electrons are elementary particles of atoms that revolve around and outside the nucleus and have a negative charge. This booklet discusses how electrons relate to electricity, some applications of electrons, electrons as waves, electrons in atoms and solids, the electron microscope, among other things.

  16. Hard electronics; Hard electronics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Hard material technologies were surveyed to establish the hard electronic technology which offers superior characteristics under hard operational or environmental conditions as compared with conventional Si devices. The following technologies were separately surveyed: (1) The device and integration technologies of wide gap hard semiconductors such as SiC, diamond and nitride, (2) The technology of hard semiconductor devices for vacuum micro- electronics technology, and (3) The technology of hard new material devices for oxides. The formation technology of oxide thin films made remarkable progress after discovery of oxide superconductor materials, resulting in development of an atomic layer growth method and mist deposition method. This leading research is expected to solve such issues difficult to be easily realized by current Si technology as high-power, high-frequency and low-loss devices in power electronics, high temperature-proof and radiation-proof devices in ultimate electronics, and high-speed and dense- integrated devices in information electronics. 432 refs., 136 figs., 15 tabs.

  17. Overshoot in Leaf Development of Ponderosa Pine in Wet Years Leads to Bark Beetle Outbreaks on Fine-Textured Soils in Drier Years

    Science.gov (United States)

    Peterman, W. L.; Waring, R. H.

    2014-12-01

    Frequent outbreaks of insects and diseases have been recorded in forests of western North America during the past few decades, but the distribution of these outbreaks has not been uniform. In some cases, recent climatic variations along with the age and density of forests may explain some spatial variation. Forest managers and policy makers would benefit if areas prone to disturbance could be recognized so that mitigating actions could be taken. In this paper, we used two ponderosa pine-dominated sites in western Montana, U.S.A. to apply a modelling approach that couples information from remote sensing, soil surveys, and local weather stations to assess where bark beetle outbreaks might first occur and why. There was a slight downward trend in precipitation for both sites over the period between 1998 and 2010, and, interannual variability was high. Some years showed large increases followed by sharp decreases. Both sites had similar topography and fire histories, but bark beetle activity occurred earlier and more severely on one site than the other. The initial canopy density of the two sites was also similar, with leaf area indices derived via Landsat imagery ranging between 1.6- 2.0 m2 m-2. We wondered if the difference in bark beetle activity might be related to soils that were fine-textured at site I and coarse-textured at site II. We applied a process-based stand growth model (3-PG) to analyze the data and evaluate the hypotheses.

  18. Variability in the intraspecific response of Pinus ponderosa seedlings subjected to long-term exposure to elevated CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Houpis, J.L.J.; Anschel, D.J. [Lawrence Livermore National Lab., CA (United States). Health and Ecological Assessment Div.; Pushnik, J.C. [California State Univ., Chico, CA (United States). Dept. of Biological Sciences; Anderson, P.D. [Forest Service, Rhinelander, WI (United States)

    1995-01-01

    The authors are investigating the effects of elevated CO{sub 2} and intraspecific variability on Pinus ponderosa. To analyze intraspecific variability, they included seedling source (family) as an additional treatment, using a split-plot experimental design. The three elevated CO{sub 2} treatments were ambient (approx. 350 ppm CO{sub 2}), ambient + 175 ppm CO{sub 2} and ambient +350 ppm CO{sub 2}. Their study uses the source/sink control framework at several key integrating steps, incorporating the long-term effects of elevated CO{sub 2} (insuring sufficient time for the expression of any long-term physiological and biochemical acclimation to occur) and genetics (using multiple species and multiple known genetic sources) in an attempt to ascertain the extent of overall regulation contributed by selected independent regulatory process at the physiological, biochemical and structural level. In order to assess intraspecific variability, this paper reports on the integration of measurements of photosynthesis, chlorophyll fluorescence, pigmentation, RuBPCase, SPSase to quantify the effects of elevated CO{sub 2} on the growth response of various families of the same species.

  19. Mountain pine beetle in high-elevation five-needle white pine ecosystems

    Science.gov (United States)

    Barbara Bentz; Elizabeth Campbell; Ken Gibson; Sandra Kegley; Jesse Logan; Diana Six

    2011-01-01

    Across western North America mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Curculionidae, Scolytinae), populations are growing at exponential rates in pine ecosystems that span a wide range of elevations. As temperature increased over the past several decades, the flexible, thermally-regulated life-history strategies of mountain pine beetle have allowed...

  20. Monitoring white pine blister rust infection and mortality in whitebark pine in the Greater Yellowstone ecosystem

    Science.gov (United States)

    Cathie Jean; Erin Shanahan; Rob Daley; Gregg DeNitto; Dan Reinhart; Chuck Schwartz

    2011-01-01

    There is a critical need for information on the status and trend of whitebark pine (Pinus albicaulis) in the Greater Yellowstone Ecosystem (GYE). Concerns over the combined effects of white pine blister rust (WPBR, Cronartium ribicola), mountain pine beetle (MPB, Dendroctonus ponderosae), and climate change prompted an interagency working group to design and implement...

  1. Limber pine forests on the leading edge of white pine blister rust distribution in Northern Colorado

    Science.gov (United States)

    Jennifer G. Klutsch; Betsy A. Goodrich; Anna W. Schoettle

    2011-01-01

    The combined threats of the current mountain pine beetle (Dendroctonus ponderosae, MPB) epidemic with the imminent invasion of white pine blister rust (caused by the non-native fungus Cronartium ribicola, WPBR) in limber pine (Pinus flexilis) forests in northern Colorado threatens the limber pine's regeneration cycle and ecosystem function. Over one million...

  2. Model-based time-series analysis of FIA panel data absent re-measurements

    Science.gov (United States)

    Raymond L. Czaplewski; Mike T. Thompson

    2013-01-01

    An epidemic of lodgepole pine (Pinus contorta) mortality from the mountain pine beetle (Dendroctonus ponderosae) has swept across the Interior West. Aerial surveys monitor the areal extent of the epidemic, but only Forest Inventory and Analysis (FIA) field data support a detailed assessment at the tree level. Dynamics of the lodgepole pine population occur at a more...

  3. Persistent reduced ecosystem respiration after insect disturbance in high elevation forests

    Science.gov (United States)

    David J. P. Moore; Nicole A. Trahan; Phil Wilkes; Tristan Quaife; Britton B. Stephens; Kelly Elder; Ankur R. Desai; Jose Negron; Russell K. Monson

    2013-01-01

    Amid a worldwide increase in tree mortality, mountain pine beetles (Dendroctonus ponderosae Hopkins) have led to the death of billions of trees from Mexico to Alaska since 2000. This is predicted to have important carbon, water and energy balance feedbacks on the Earth system. Counter to current projections, we show that on a decadal scale, tree mortality causes no...

  4. Mountain pine beetle population sampling: inferences from Lindgren pheromone traps and tree emergence cages

    Science.gov (United States)

    Barbara J. Bentz

    2006-01-01

    Lindgren pheromone traps baited with a mountain pine beetle (Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae, Scolytinae)) lure were deployed for three consecutive years in lodgepole pine stands in central Idaho. Mountain pine beetle emergence was also monitored each year using cages on infested trees. Distributions of beetles caught in...

  5. Mountain pine beetles use volatile cues to locate host limber pine and avoid non-host Great Basin bristlecone pine

    Science.gov (United States)

    Curtis A. Gray; Justin B. Runyon; Michael J. Jenkins; Andrew D. Giunta

    2015-01-01

    The tree-killing mountain pine beetle (Dendroctonus ponderosae Hopkins) is an important disturbance agent of western North American forests and recent outbreaks have affected tens of millions of hectares of trees. Most western North American pines (Pinus spp.) are hosts and are successfully attacked by mountain pine beetles whereas a handful of pine species are not...

  6. Mountain pine beetle attack alters the chemistry and flammability of lodgepole pine foliage

    Science.gov (United States)

    Wesley G. Page; Michael J. Jenkins; Justin B. Runyon

    2012-01-01

    During periods with epidemic mountain pine beetle (Dendroctonus ponderosae Hopkins) populations in lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) forests, large amounts of tree foliage are thought to undergo changes in moisture content and chemistry brought about by tree decline and death. However, many of the presumed changes have yet to be...

  7. Interactions among the mountain pine beetle, fires, and fuels

    Science.gov (United States)

    Michael J. Jenkins; Justin B. Runyon; Christopher J. Fettig; Wesley G. Page; Barbara J. Bentz

    2014-01-01

    Bark beetle outbreaks and wildfires are principal drivers of change in western North American forests, and both have increased in severity and extent in recent years. These two agents of disturbance interact in complex ways to shape forest structure and composition. For example, mountain pine beetle, Dendroctonus ponderosae Hopkins, epidemics alter forest fuels with...

  8. A range-wide restoration strategy for whitebark pine (Pinus albicaulis)

    Science.gov (United States)

    Robert E. Keane; D. F. Tomback; C. A. Aubry; A. D. Bower; E. M. Campbell; C. L. Cripps; M. B. Jenkins; M. F. Mahalovich; M. Manning; S. T. McKinney; M. P. Murray; D. L. Perkins; D. P. Reinhart; C. Ryan; A. W. Schoettle; C. M. Smith

    2012-01-01

    Whitebark pine (Pinus albicaulis), an important component of western high-elevation forests, has been declining in both the United States and Canada since the early Twentieth Century from the combined effects of mountain pine beetle (Dendroctonus ponderosae) outbreaks, fire exclusion policies, and the spread of the exotic disease white pine blister rust (caused by the...

  9. Dose-dependent pheromone responses of mountain pine beetle in stands of lodgepole pine

    Science.gov (United States)

    Daniel R. Miller; B. Staffan Lindgren; John H. Borden

    2005-01-01

    We conducted seven behavioral choice tests with Lindgren multiple-funnel traps in stands of mature lodgepole pine in British Columbia, from 1988 to 1994, to determine the dosedependent responses of the mountain pine beetle, Dendroctonus ponderosae Hopkins, to its pheromones. Amultifunctional dose-dependent response was exhibited by D. ...

  10. Verbenone: Dose-Dependent Interruption of Pheromone-Based Attraction of Three Sympatric Species of Pine Bark Beetles (Coleoptera: Scolytidae)

    Science.gov (United States)

    Daniel R. Miller; John H. Borden; B. Staffan Lindgren

    1995-01-01

    Verbenone significantly reduced catches of Ips latidens (LeConte), I. pini (Say), and Dendroctonus ponderosae Hopkins in multiple-funnel traps, baited with aggregation pheromones, in stands of lodgepole pine in southern British Columbia. Interruption of attraction was dose dependent for all three species. There...

  11. Selection for resistance to white pine blister rust affects the abiotic stress tolerances of limber pine

    Science.gov (United States)

    Patrick J. Vogan; Anna W. Schoettle

    2015-01-01

    Limber pine (Pinus flexilis) mortality is increasing across the West as a result of the combined stresses of white pine blister rust (Cronartium ribicola; WPBR), mountain pine beetle (Dendroctonus ponderosae), and dwarf mistletoe (Arceuthobium cyanocarpum) in a changing climate. With the continued spread of WPBR, extensive mortality will continue with strong selection...

  12. Pre-dispersal seed predator dynamics at the northern limits of limber pine distribution

    Science.gov (United States)

    Vernon S. Peters

    2011-01-01

    Limber pine (Pinus flexilis) is listed provincially as endangered in the northern part of its geographic range (Alberta) due to the high mortality caused by white pine blister rust (WPBR) (Cronartium ribicola) and mountain pine beetle (Dendroctonus ponderosae), and limited regeneration opportunities due to fire exclusion. In the case of an endangered species, seed...

  13. Evaluation of mountain beetle-infested lodgepole pine for cellulosic ethanol production by sulfite pretreatment to overcome recalcitrance of lignocellulose

    Science.gov (United States)

    X. Luo; R. Gleisner; S. Tian; J. Negron; W. Zhu; E. Horn; X. J. Pan; J. Y. Zhu

    2010-01-01

    The potentials of deteriorated mountain pine beetle (Dendroctonus ponderosae)-killed lodgepole pine (Pinus contorta) trees for cellulosic ethanol production were evaluated using the sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) process. The trees were harvested from two sites in the United States Arapaho-Roosevelt National Forest, Colorado....

  14. Why Mountain Pine Beetle Exacerbates a Principal-agent Relationship: Exploring Strategic Policy Responses to Beetle Attack in a Mixed Species Forest

    NARCIS (Netherlands)

    Bogle, T.; Kooten, van G.C.

    2012-01-01

    The management of public forestland is often carried out by private forest companies, in which case the landowner needs to exercise care in dealing with catastrophic natural disturbance. We use the mountain pine beetle (Dendroctonus ponderosae Hopkins, 1902) damage in British Columbia to explore how

  15. Assessing the potential for maladaptation during active management of limber pine populations: A common garden study detects genetic differentiation in response to soil moisture in the Southern Rocky Mountains

    Science.gov (United States)

    Erin M. Borgman; Anna W. Schoettle; Amy L. Angert

    2015-01-01

    Active management is needed to sustain healthy limber pine (Pinus flexilis E. James) forests in the Southern Rocky Mountains (henceforth, Southern Rockies), as they are threatened by the interaction of the mountain pine beetle (Dendroctonus ponderosae Hopkins) epidemic, climate change, and the spread of the non-native pathogen that causes white pine blister...

  16. Why Mountain Pine Beetle Exacerbates a Principal-agent Relationship: Exploring Strategic Policy Responses to Beetle Attack in a Mixed Species Forest

    NARCIS (Netherlands)

    Bogle, T.; Kooten, van G.C.

    2012-01-01

    The management of public forestland is often carried out by private forest companies, in which case the landowner needs to exercise care in dealing with catastrophic natural disturbance. We use the mountain pine beetle (Dendroctonus ponderosae Hopkins, 1902) damage in British Columbia to explore how

  17. Ambient Electronics

    Science.gov (United States)

    Sekitani, Tsuyoshi; Someya, Takao

    2012-10-01

    We report the recent research progress and future prospects of flexible and printed electronics, focusing on molecular electronic material-based thin-film transistors, which are expected to usher in a new era of electronics.

  18. Electron cooling

    Science.gov (United States)

    Meshkov, I.; Sidorin, A.

    2004-10-01

    The brief review of the most significant and interesting achievements in electron cooling method, which took place during last two years, is presented. The description of the electron cooling facilities-storage rings and traps being in operation or under development-is given. The applications of the electron cooling method are considered. The following modern fields of the method development are discussed: crystalline beam formation, expansion into middle and high energy electron cooling (the Fermilab Recycler Electron Cooler, the BNL cooler-recuperator, cooling with circulating electron beam, the GSI project), electron cooling in traps, antihydrogen generation, electron cooling of positrons (the LEPTA project).

  19. Adventitious Bud Induction and Plantlet Regeneration in vitro from Mature Zygotic Embryos of Ponderosa Pine%离体条件下西黄松成熟合子胚不定芽的诱导及植株再生

    Institute of Scientific and Technical Information of China (English)

    李科友; 唐德瑞; 李林; 朱海兰; 赵忠; 侯琳

    2008-01-01

    Adventitious buds were induced from the excised mature zygotic embryos of Ponderosa Pine (Pinus ponderosa). Thehighest induction rate (65.8%) of adventitious buds was obtained with 10-fold multiplication at the highest and 7-foldformation of adventitious buds. Buds proliferation and elongation were achieved on 1/2GD and 1/2SH without growth regulators.A proper amount of activated charcoal promoted adventitious buds elongation and root' growth. The adventitious shoots ofPonderosa Pine were used to induce adventitious roots on 1/2GD and 1/2SH media supplemented with different concentrations ofNAA and GA . The results showed that NAA played a determinative role in initiating the adventitious roots. Sixteen point sevenpaper, the experimental results showed that roots were successfully induced from cultured mature zygotic embryos of PonderosaPine.%以西黄松成熟胚为外植体诱导不定芽,在GD+9.85~19.70 μmol·L'-1 6-BA+0.0~14.42 μmol·L-1 NAA上不定芽诱导率最高达65.8%,平均增殖率为7,最大增殖率达10;不定芽形成有2种途径,即子叶直接形成不定芽和子叶组织再分化形成不定芽;NAA不利于外植体不定芽的诱导;不定芽的生长和扩繁采用不加生长调节剂的1/2 GD和1/2 SH培养基;培养基中加入适量的活性炭有利于不定芽和根的生长.不定嫩梢在1/2 GD和1/2 SH附加不同浓度NAA和GA,3的培养基上进行生根诱导,试验结果表明:NAA对不定根的形成起主要作用,在1/2 GD+28.84 μmol·L'-1 NAA+4.17 μmol·L'-1 GA,3培养基中不定梢的生根率为16.7%.在离体培养条件下,以西黄松成熟胚为外植体获得了再生植株.

  20. Whole System Carbon Exchange of Small Stands of Pinus Ponderosa Growing at Different CO{sub 2} concentrations in open top chambers

    Energy Technology Data Exchange (ETDEWEB)

    Ball, J. Timothy; Ross, Peter D.; Picone, John B.; Eichelmann, Hillar Y.; Ross, Gregory N.

    1996-12-01

    Functional understanding of the carbon cycle from the molecular to the global level is a high scientific priority requiring explanation of the relationship between fluxes at different spatial and temporal scales. We describe methods used to convert an open top chamber into both closed and open flow gas exchange systems utilized to measure such fluxes. The systems described consist of temporary modifications to an open top chamber, and are put in place for several days on one or several open top chambers. In the closed system approach, a chamber is quickly sealed for a short, predetermined time interval, the change in gas concentrations is measured, then the chamber is unsealed and ventilated. In the open flow system approach, airflow into the open top chamber is measured by trace gas injection, and the air stream concentration of CO{sub 2} and water vapor is measured before and after injection into the chamber. The closed chamber approach can resolve smaller fluxes, but causes transient increases in chamber air temperature, and has a high labor requirement. The open flow approach reduces the deviation of measuring conditions from ambient, may be semi-automated (requiring less labor), allows a more frequent sampling interval, but cannot resolve low fluxes well. Data demonstrating the capabilities of these systems show that, in open canopies of ponderosa pine, scaling fluxes from leaves to whole canopies is well approximated from summation of leaf P{sub s} rates. Flux measurements obtained from these systems can be a valuable contribution to our understanding whole system material fluxes, and challenge our understanding of ecosystem carbon budgets.

  1. Average Stand Age from Forest Inventory Plots Does Not Describe Historical Fire Regimes in Ponderosa Pine and Mixed-Conifer Forests of Western North America.

    Science.gov (United States)

    Stevens, Jens T; Safford, Hugh D; North, Malcolm P; Fried, Jeremy S; Gray, Andrew N; Brown, Peter M; Dolanc, Christopher R; Dobrowski, Solomon Z; Falk, Donald A; Farris, Calvin A; Franklin, Jerry F; Fulé, Peter Z; Hagmann, R Keala; Knapp, Eric E; Miller, Jay D; Smith, Douglas F; Swetnam, Thomas W; Taylor, Alan H

    Quantifying historical fire regimes provides important information for managing contemporary forests. Historical fire frequency and severity can be estimated using several methods; each method has strengths and weaknesses and presents challenges for interpretation and verification. Recent efforts to quantify the timing of historical high-severity fire events in forests of western North America have assumed that the "stand age" variable from the US Forest Service Forest Inventory and Analysis (FIA) program reflects the timing of historical high-severity (i.e. stand-replacing) fire in ponderosa pine and mixed-conifer forests. To test this assumption, we re-analyze the dataset used in a previous analysis, and compare information from fire history records with information from co-located FIA plots. We demonstrate that 1) the FIA stand age variable does not reflect the large range of individual tree ages in the FIA plots: older trees comprised more than 10% of pre-stand age basal area in 58% of plots analyzed and more than 30% of pre-stand age basal area in 32% of plots, and 2) recruitment events are not necessarily related to high-severity fire occurrence. Because the FIA stand age variable is estimated from a sample of tree ages within the tree size class containing a plurality of canopy trees in the plot, it does not necessarily include the oldest trees, especially in uneven-aged stands. Thus, the FIA stand age variable does not indicate whether the trees in the predominant size class established in response to severe fire, or established during the absence of fire. FIA stand age was not designed to measure the time since a stand-replacing disturbance. Quantification of historical "mixed-severity" fire regimes must be explicit about the spatial scale of high-severity fire effects, which is not possible using FIA stand age data.

  2. Characterization of vegetation properties: Canopy modeling of pinyon-juniper and ponderosa pine woodlands; Final report. Modeling topographic influences on solar radiation: A manual for the SOLARFLUX model

    Energy Technology Data Exchange (ETDEWEB)

    Rich, P.M.; Hetrick, W.A.; Saving, S.C.

    1994-12-31

    This report is comprised of two studies. The first study focuses on plant canopies in pinyon-juniper woodland, ponderosa pine woodland, and waste sites at Los Alamos National Laboratory which involved five basic areas of research: (1) application of hemispherical photography and other gap fraction techniques to study solar radiation regimes and canopy architecture, coupled with application of time-domain reflectometry to study soil moisture; (2) detailed characterization of canopy architecture using stand mapping and allometry; (3) development of an integrated geographical information system (GIS) database for relating canopy architecture with ecological, hydrological, and system modeling approaches; (4) development of geometric models that simulate complex sky obstruction, incoming solar radiation for complex topographic surfaces, and the coupling of incoming solar radiation with energy and water balance, with simulations of incoming solar radiation for selected native vegetation and experimental waste cover design sites; and (5) evaluation of the strengths and limitations of the various field sampling techniques. The second study describes an approach to develop software that takes advantage of new generation computers to model insolation on complex topographic surfaces. SOLARFLUX is a GIS-based (ARC/INFO, GRID) computer program that models incoming solar radiation based on surface orientation (slope and aspect), solar angle (azimuth and zenith) as it shifts over time, shadows caused by topographic features, and atmospheric conditions. This manual serves as the comprehensive guide to SOLARFLUX. Included are discussions on modelling insolation on complex surfaces, the theoretical approach, program setup and operation, and a set of applications illustrating characteristics of topographic insolation modelling.

  3. Average Stand Age from Forest Inventory Plots Does Not Describe Historical Fire Regimes in Ponderosa Pine and Mixed-Conifer Forests of Western North America.

    Directory of Open Access Journals (Sweden)

    Jens T Stevens

    Full Text Available Quantifying historical fire regimes provides important information for managing contemporary forests. Historical fire frequency and severity can be estimated using several methods; each method has strengths and weaknesses and presents challenges for interpretation and verification. Recent efforts to quantify the timing of historical high-severity fire events in forests of western North America have assumed that the "stand age" variable from the US Forest Service Forest Inventory and Analysis (FIA program reflects the timing of historical high-severity (i.e. stand-replacing fire in ponderosa pine and mixed-conifer forests. To test this assumption, we re-analyze the dataset used in a previous analysis, and compare information from fire history records with information from co-located FIA plots. We demonstrate that 1 the FIA stand age variable does not reflect the large range of individual tree ages in the FIA plots: older trees comprised more than 10% of pre-stand age basal area in 58% of plots analyzed and more than 30% of pre-stand age basal area in 32% of plots, and 2 recruitment events are not necessarily related to high-severity fire occurrence. Because the FIA stand age variable is estimated from a sample of tree ages within the tree size class containing a plurality of canopy trees in the plot, it does not necessarily include the oldest trees, especially in uneven-aged stands. Thus, the FIA stand age variable does not indicate whether the trees in the predominant size class established in response to severe fire, or established during the absence of fire. FIA stand age was not designed to measure the time since a stand-replacing disturbance. Quantification of historical "mixed-severity" fire regimes must be explicit about the spatial scale of high-severity fire effects, which is not possible using FIA stand age data.

  4. 油松萜烯成分变化与红脂大小蠹的反应特性%The variance in monoterpene composition of Pinus tabuliformis and their effect on the electrophsiological and behavioral responses of Dendroctonus valens

    Institute of Scientific and Technical Information of China (English)

    张龙娃; 刘柱东; 姚剑

    2009-01-01

    采用顶空采样方法,比较健康油松、人工损伤油松以及抗性油松在单萜烯成分组成上的差异.GC.MS分析表明,在自然状况下,油松树干释放的萜烯类成分很少,以α-蒎烯占绝对优势(>97%);人工损伤后,油松萜烯类成分明显增多,除α-蒎烯为主要成分外,还包括β-蒎烯、月桂烯、柠檬烯、萜品油烯、β-水芹烯、长叶烯等;而抗性油松萜烯类成分更为复杂.对3类油松主要单萜类成分的相对含量方差分析表明,α-蒎烯的相对含量呈显著降低;3-蒈烯在损伤寄主中相对含量最高,在抗性寄主中相对含量与自然状态下没有差异.柠檬烯、莰烯、萜品油烯在抗性寄主中相对比率显著增加.而β-蒎烯、月桂烯、β-水芹烯相对含量在3个处理中变化不大.在此基础上,比较红脂大小蠢Dendroctonus valens LeConte对油松主要单萜类成分的触角电位及嗅觉行为反应.结果表明.室内触角电位、嗅觉试验与先前林间试验结果相一致,即红脂大小蠹对(+).3.蒈烯表现出最强的电生理和行为反应.对R-(+)-α-蒎烯和S-(-)-α-蒎烯研究发现,红脂大小蠹对α-蒎烯2个对映体的触角电位、嗅觉行为无显著不同.结合油松单萜类含量变化特点与红脂大小蠹行为反应,认为3-蒈烯相对含量上升可能作为易感寄主特点;而柠檬烯、莰烯、萜品油烯相对比率增加则代表了抗性或者非适合寄主的特征.

  5. Electron Microscopy.

    Science.gov (United States)

    Beer, Michael

    1980-01-01

    Reviews technical aspects of structure determination in biological electron microscopy (EM). Discusses low dose EM, low temperature microscopy, electron energy loss spectra, determination of mass or molecular weight, and EM of labeled systems. Cites 34 references. (CS)

  6. Electron Microscopy.

    Science.gov (United States)

    Beer, Michael

    1980-01-01

    Reviews technical aspects of structure determination in biological electron microscopy (EM). Discusses low dose EM, low temperature microscopy, electron energy loss spectra, determination of mass or molecular weight, and EM of labeled systems. Cites 34 references. (CS)

  7. Understand electronics

    CERN Document Server

    Bishop, Owen

    2013-01-01

    Understand Electronics provides a readable introduction to the exciting world of electronics for the student or enthusiast with little previous knowledge. The subject is treated with the minimum of mathematics and the book is extensively illustrated.This is an essential guide for the newcomer to electronics, and replaces the author's best-selling Beginner's Guide to Electronics.The step-by-step approach makes this book ideal for introductory courses such as the Intermediate GNVQ.

  8. Electronic components

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Components provides a basic grounding in the practical aspects of using and selecting electronics components. The book describes the basic requirements needed to start practical work on electronic equipment, resistors and potentiometers, capacitance, and inductors and transformers. The text discusses semiconductor devices such as diodes, thyristors and triacs, transistors and heat sinks, logic and linear integrated circuits (I.C.s) and electromechanical devices. Common abbreviations applied to components are provided. Constructors and electronics engineers will find the book useful

  9. Bark beetle management guidebook

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    This guidebook is designed to provide a background to bark beetle management practices consistent with the British Columbia Forest Practices Code, as well as specific practices for managing mountain pine beetle (Dendroctonus ponderosae), spruce beetle (Dendroctonus rufipennis), and Douglas-fir beetle (Dendroctonus pseudotsugae). It describes their general biology and distribution in British Columbia, their life cycles and population dynamics, and symptoms of bark beetle attack. General management strategies presented include prevention (a long-term approach), suppression, holding actions, and salvage. Strategies appropriate to specific bark beetles include aerial surveys, ground detection, baiting, harvesting, and use of insecticides. The guidebook includes brief mention of other bark beetles (Scolytids and other Dendroctonus species) and a glossary.

  10. Electronic Prescribing

    Science.gov (United States)

    ... Do you prescribe electronically?” For more information about electronic prescribing, call 1-800-MEDICARE (1-800-633- ... TTY users should call 1-877-486-2048 . Electronic eRx Prescribing I went to the pharmacy, and ...

  11. Basic electronics

    CERN Document Server

    Holbrook, Harold D

    1971-01-01

    Basic Electronics is an elementary text designed for basic instruction in electricity and electronics. It gives emphasis on electronic emission and the vacuum tube and shows transistor circuits in parallel with electron tube circuits. This book also demonstrates how the transistor merely replaces the tube, with proper change of circuit constants as required. Many problems are presented at the end of each chapter. This book is comprised of 17 chapters and opens with an overview of electron theory, followed by a discussion on resistance, inductance, and capacitance, along with their effects on t

  12. Electronic Government and Electronic Participation

    NARCIS (Netherlands)

    Tambouris, E.; Scholl, H.J.; Janssen, M.F.W.H.A.; Wimmer, M.A.; Tarabanis, K.; Gascó, M.; Klievink, A.J.; Lindgren, I.; Milano, M.; Panagiotopoulos, P.; Pardo, T.A.; Parycek, P.; Sæbø, O.

    2015-01-01

    Electronic government and electronic participation continue to transform the public sector and society worldwide and are constantly being transformed themselves by emerging information and communication technologies. This book presents papers from the 14th International Federation for Information P

  13. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  14. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  15. Electronic Commerce

    Directory of Open Access Journals (Sweden)

    Slavko Đerić

    2016-12-01

    Full Text Available Electronic commerce can be defined in different ways. Any definition helps to understand and explain that concept as better as possible.. Electronic commerce is a set of procedures and technologies that automate the tasks of financial transactions using electronic means. Also, according to some authors, electronic commerce is defined as a new concept, which is being developed and which includes process of buying and selling or exchanging products, services or information via computer networks, including the Internet. Electronic commerce is not limited just to buying and selling, but it also includes all pre-sales and after-sales ongoing activities along the supply chain. Introducing electronic commerce, using the Internet and Web services in business, realizes the way to a completely new type of economy - internet economy.

  16. Micropower electronics

    CERN Document Server

    Keonjian, Edward

    1964-01-01

    Micropower Electronics deals with the operation of modern electronic equipment at micropower levels and the problems associated with micropower electronics. Topics covered include the relations between minimum required power density and frequency response for semiconductor triode amplifiers; physical realization of digital logic circuits; micropower microelectronic subsystems; and metal-oxide-semiconductor field-effect devices for micropower logic circuitry. This book is comprised of 10 chapters and begins with an analysis of fundamental relationships and basic requirements pertinent to the ph

  17. Semicontinuous measurements of gas-particle partitioning of organic acids in a ponderosa pine forest using a MOVI-HRToF-CIMS

    Science.gov (United States)

    Yatavelli, R. L. N.; Stark, H.; Thompson, S. L.; Kimmel, J. R.; Cubison, M. J.; Day, D. A.; Campuzano-Jost, P.; Palm, B. B.; Hodzic, A.; Thornton, J. A.; Jayne, J. T.; Worsnop, D. R.; Jimenez, J. L.

    2014-02-01

    Hundreds of gas- and particle-phase organic acids were measured in a rural ponderosa pine forest in Colorado, USA, during BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen - Rocky Mountain Biogenic Aerosol Study). A recently developed micro-orifice volatilization impactor high-resolution time-of-flight chemical ionization mass spectrometer (MOVI-HRToF-CIMS) using acetate (CH3C(O)O-) as the reagent ion was used to selectively ionize and detect acids semicontinuously from 20 to 30 August 2011, with a measurement time resolution of ~1.5 h. At this site 98% of the organic acid mass is estimated to be in the gas phase, with only ~2% in the particle phase. We investigated gas-particle partitioning, quantified as the fraction in the particle phase (Fp), of C1-C18 alkanoic acids, six known terpenoic acids, and bulk organic acids vs. carbon number. Data were compared to the absorptive partitioning model and suggest that bulk organic acids at this site follow absorptive partitioning to the organic aerosol mass. The rapid response (<1-2 h) of partitioning to temperature changes for bulk acids suggests that kinetic limitations to equilibrium are minor, which is in contrast to conclusions of some recent laboratory and field studies, possibly due to lack of very low ambient relative humidities at this site. Time trends for partitioning of individual and groups of acids were mostly captured by the model, with varying degrees of absolute agreement. Species with predicted substantial fractions in both the gas and particle phases show better absolute agreement, while species with very low predicted fractions in one phase often show poor agreement, potentially due to thermal decomposition, inlet adsorption, or other issues. Partitioning to the aqueous phase is predicted to be smaller than to the organic phase for alkanoic and bulk acids, and has different trends with time and carbon number than observed experimentally. This is due

  18. Semi-continuous measurements of gas/particle partitioning of organic acids in a ponderosa pine forest using a MOVI-HRToF-CIMS

    Science.gov (United States)

    Yatavelli, R. L. N.; Stark, H.; Thompson, S. L.; Kimmel, J. R.; Cubison, M. J.; Day, D. A.; Campuzano-Jost, P.; Palm, B. B.; Thornton, J. A.; Jayne, J. T.; Worsnop, D. R.; Jimenez, J. L.

    2013-06-01

    Hundreds of gas and particle phase organic acids were measured in a rural ponderosa pine forest in Colorado, USA, during the Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen - Rocky Mountain Biogenic Aerosol Study (BEACHON-RoMBAS). A recently developed Micro-Orifice Volatilization Impactor High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (MOVI-HRToF-CIMS) using acetate (CH3C(O)O-) as the reagent ion was used to selectively ionize and detect acids semi-continuously from 20-30 August 2011, with a measurement time resolution of ~1.5 h. At this site 98% of the organic acid mass is estimated to be in the gas-phase, with only ~2% in the particle phase. We investigated gas/particle partitioning, quantified as the fraction in the particle phase (Fp), of C1-C18 alkanoic acids, six known terpenoic acids and total bulk organic acids. Data were compared to the absorptive partitioning model and suggest that bulk organic acids at this site follow absorptive partitioning to the organic aerosol mass. The rapid response (<1-2 h) of partitioning to temperature changes for bulk acids suggests that kinetic limitations to equilibrium are minor, which is in contrast to conclusions of some recent laboratory and field studies, possibly due to lack of very low ambient relative humidities at this site. Time trends for partitioning of individual and groups of acids were mostly captured by the model, with varying degrees of absolute agreement. Species with predicted substantial fractions in both the gas and particle phases show better absolute agreement, while species with very low predicted fractions in one phase often show agreement on trends, but poor absolute agreement, potentially due to thermal decomposition, inlet adsorption, or other issues. Based on measurement-model comparison we conclude that species carbon number and oxygen content, together with ambient temperature control the volatility of organic acids and are good

  19. Semi-continuous measurements of gas/particle partitioning of organic acids in a ponderosa pine forest using a MOVI-HRToF-CIMS

    Directory of Open Access Journals (Sweden)

    R. L. N. Yatavelli

    2013-06-01

    Full Text Available Hundreds of gas and particle phase organic acids were measured in a rural ponderosa pine forest in Colorado, USA, during the Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen – Rocky Mountain Biogenic Aerosol Study (BEACHON-RoMBAS. A recently developed Micro-Orifice Volatilization Impactor High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (MOVI-HRToF-CIMS using acetate (CH3C(OO- as the reagent ion was used to selectively ionize and detect acids semi-continuously from 20–30 August 2011, with a measurement time resolution of ~1.5 h. At this site 98% of the organic acid mass is estimated to be in the gas-phase, with only ~2% in the particle phase. We investigated gas/particle partitioning, quantified as the fraction in the particle phase (Fp, of C1–C18 alkanoic acids, six known terpenoic acids and total bulk organic acids. Data were compared to the absorptive partitioning model and suggest that bulk organic acids at this site follow absorptive partitioning to the organic aerosol mass. The rapid response (<1–2 h of partitioning to temperature changes for bulk acids suggests that kinetic limitations to equilibrium are minor, which is in contrast to conclusions of some recent laboratory and field studies, possibly due to lack of very low ambient relative humidities at this site. Time trends for partitioning of individual and groups of acids were mostly captured by the model, with varying degrees of absolute agreement. Species with predicted substantial fractions in both the gas and particle phases show better absolute agreement, while species with very low predicted fractions in one phase often show agreement on trends, but poor absolute agreement, potentially due to thermal decomposition, inlet adsorption, or other issues. Based on measurement-model comparison we conclude that species carbon number and oxygen content, together with ambient temperature control the volatility of organic

  20. Does overshoot in leaf development of ponderosa pine in wet years leads to bark beetle outbreaks on fine-textured soils in drier years?

    Directory of Open Access Journals (Sweden)

    Wendy Peterman

    2014-12-01

    Full Text Available Background Frequent outbreaks of insects and diseases have been recorded in the native forests of western North America during the last few decades, but the distribution of these outbreaks has been far from uniform. In some cases, recent climatic variations may explain some of this spatial variation along with the presence of expansive forests composed of dense, older trees. Forest managers and policy makers would benefit if areas especially prone to disturbance could be recognized so that mitigating actions could be taken. Methods We use two ponderosa pine-dominated sites in western Montana, U.S.A. to apply a modeling approach that couples information acquired via remote sensing, soil surveys, and local weather stations to assess where bark beetle outbreaks might first occur and why. Although there was a general downward trend in precipitation for both sites over the period between 1998 and 2010 (slope = −1.3, R2 = 0.08, interannual variability was high. Some years showed large increases followed by sharp decreases. Both sites had similar topography and fire histories, but bark beetle activity occurred earlier (circa 2000 to 2001 and more severely on one site than on the other. The initial canopy density of the two sites was also similar, with leaf area indices ranging between 1.7-2.0 m2·m−2. We wondered if the difference in bark beetle activity was related to soils that were higher in clay content at site I than at site II. To assess this possibility, we applied a process-based stand growth model (3-PG to analyze the data and evaluate the hypotheses. Results We found that when wet years were followed by drier years, the simulated annual wood production per unit of leaf area, a measure of tree vigor, dropped below a critical threshold on site I but not on site II. Conclusion We concluded that the difference in vulnerability of the two stands to beetle outbreaks can be explained largely by differences in gross photosynthesis

  1. Microfluidic electronics.

    Science.gov (United States)

    Cheng, Shi; Wu, Zhigang

    2012-08-21

    Microfluidics, a field that has been well-established for several decades, has seen extensive applications in the areas of biology, chemistry, and medicine. However, it might be very hard to imagine how such soft microfluidic devices would be used in other areas, such as electronics, in which stiff, solid metals, insulators, and semiconductors have previously dominated. Very recently, things have radically changed. Taking advantage of native properties of microfluidics, advances in microfluidics-based electronics have shown great potential in numerous new appealing applications, e.g. bio-inspired devices, body-worn healthcare and medical sensing systems, and ergonomic units, in which conventional rigid, bulky electronics are facing insurmountable obstacles to fulfil the demand on comfortable user experience. Not only would the birth of microfluidic electronics contribute to both the microfluidics and electronics fields, but it may also shape the future of our daily life. Nevertheless, microfluidic electronics are still at a very early stage, and significant efforts in research and development are needed to advance this emerging field. The intention of this article is to review recent research outcomes in the field of microfluidic electronics, and address current technical challenges and issues. The outlook of future development in microfluidic electronic devices and systems, as well as new fabrication techniques, is also discussed. Moreover, the authors would like to inspire both the microfluidics and electronics communities to further exploit this newly-established field.

  2. Paper electronics.

    Science.gov (United States)

    Tobjörk, Daniel; Österbacka, Ronald

    2011-05-03

    Paper is ubiquitous in everyday life and a truly low-cost substrate. The use of paper substrates could be extended even further, if electronic applications would be applied next to or below the printed graphics. However, applying electronics on paper is challenging. The paper surface is not only very rough compared to plastics, but is also porous. While this is detrimental for most electronic devices manufactured directly onto paper substrates, there are also approaches that are compatible with the rough and absorptive paper surface. In this review, recent advances and possibilities of these approaches are evaluated and the limitations of paper electronics are discussed.

  3. Electron holography

    CERN Document Server

    Tonomura, Akira

    1993-01-01

    Holography was devised for breaking through the resolution limit of electron microscopes The advent of a "coherent" field emission electron beam has enabled the use of Electron Holography in various areas of magnetic domain structures observation, fluxon observation in superconductors, and fundamental experiments in physics which have been inaccessible using other techniques After examining the fundamentals of electron holography and its applications to the afore mentioned fields, a detailed discussion of the Aharonov-Bohm effect and the related experiments is presented Many photographs and illustrations are included to elucidate the text

  4. Polymer electronics

    CERN Document Server

    Hsin-Fei, Meng

    2013-01-01

    Polymer semiconductor is the only semiconductor that can be processed in solution. Electronics made by these flexible materials have many advantages such as large-area solution process, low cost, and high performance. Researchers and companies are increasingly dedicating time and money in polymer electronics. This book focuses on the fundamental materials and device physics of polymer electronics. It describes polymer light-emitting diodes, polymer field-effect transistors, organic vertical transistors, polymer solar cells, and many applications based on polymer electronics. The book also disc

  5. Electronic Photography

    Science.gov (United States)

    Payne, Meredith Lindsay

    1995-01-01

    The main objective was to assist in the production of electronic images in the Electronic Photography Lab (EPL). The EPL is a new facility serving the electronic photographic needs of the Langley community. The purpose of the Electronic Photography lab is to provide Langley with access to digital imaging technology. Although the EPL has been in operation for less than one year, almost 1,000 images have been produced. The decision to establish the lab was made after careful determination of the centers needs for electronic photography. The LaRC community requires electronic photography for the production of electronic printing, Web sites, desktop publications, and its increased enhancement capabilities. In addition to general use, other considerations went into the planning of the EPL. For example, electronic photography is much less of a burden on the environment compared to conventional photography. Also, the possibilities of an on-line database and retrieval system could make locating past work more efficient. Finally, information in an electronic image is quantified, making measurements and calculations easier for the researcher.

  6. Electron Bifurcation

    Energy Technology Data Exchange (ETDEWEB)

    Peters, John W.; Miller, Anne-Frances; Jones, Anne K.; King, Paul W.; Adams, Michael W. W.

    2016-04-01

    Electron bifurcation is the recently recognized third mechanism of biological energy conservation. It simultaneously couples exergonic and endergonic oxidation-reduction reactions to circumvent thermodynamic barriers and minimize free energy loss. Little is known about the details of how electron bifurcating enzymes function, but specifics are beginning to emerge for several bifurcating enzymes. To date, those characterized contain a collection of redox cofactors including flavins and iron-sulfur clusters. Here we discuss the current understanding of bifurcating enzymes and the mechanistic features required to reversibly partition multiple electrons from a single redox site into exergonic and endergonic electron transfer paths.

  7. Printed Electronics

    Science.gov (United States)

    Crain, John M. (Inventor); Lettow, John S. (Inventor); Aksay, Ilhan A. (Inventor); Korkut, Sibel (Inventor); Chiang, Katherine S. (Inventor); Chen, Chuan-Hua (Inventor); Prud'Homme, Robert K. (Inventor)

    2016-01-01

    Printed electronic device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed electronic devices is further disclosed.

  8. 红脂大小蠹的捕食性天敌——大唼蜡甲发育和温度的关系研究%Study on the Relationship between Growth and Environmental Temperature of Rhizophagus grandis (Coleoptera: Rhizophagidae), An Important Predator of Dendroctonus valens (Coleoptera: Scolytidae)

    Institute of Scientific and Technical Information of China (English)

    魏建荣; 丁保福; 唐艳龙; 赵建兴; 杨忠岐

    2010-01-01

    @@ 大唼蜡甲(Rhizophagus grandis Gyllenhal) 属鞘翅目唼蜡甲科(Coleoptera: Rhizophagidae),是云杉大小蠹(Dendroctonus micans Kugelann)(鞘翅目:小蠹科)(Coleoptera:Scolytidae)的主要捕食性天敌,其成虫和幼虫均可捕食云杉大小蠹的卵、幼虫和蛹,在自然调节这种重要害虫的种群数量上发挥着重要作用[1-2].云杉大小蠹原分布于前苏联,我国黑龙江、辽宁、青海、甘肃、四川省也有分布,从上世纪初逐渐向西、向南扩散至欧洲的法国、英国,现分布于欧亚大陆的几乎所有的云杉(Picea spp.)的针叶林中.其天敌大唼腊甲随后也跟随云杉大小蠹的扩散而逐步迁移,但自然传播的速度很慢,种群数量较低,在云杉大小蠹新传入区很难达到自然控制的程度.为此,欧洲一些国家开展了大唼腊甲的引进、人工繁殖和释放防治云杉大小蠹的研究.如早在1963年格鲁吉亚就研究利用其防治云杉大小蠹[3].上世纪中后期,云杉大小蠹在欧洲大发生,严重危害挪威云杉(Picea abies (L.) Karst.).为了防治这种重要的蛀干害虫,比利时从上世纪50年代起就开展了利用大唼腊甲生物防治云杉大小蠹的研究.1978年,英国和法国等国家先后从比利时引进大唼蜡甲,取得了良好的控制效果[4-5].随后美国也引进大唼腊甲防治黑脂大小蠹(Dendroctonus terebrans Olivier)[6].

  9. Electron optics

    CERN Document Server

    Grivet, Pierre; Bertein, F; Castaing, R; Gauzit, M; Septier, Albert L

    1972-01-01

    Electron Optics, Second English Edition, Part I: Optics is a 10-chapter book that begins by elucidating the fundamental features and basic techniques of electron optics, as well as the distribution of potential and field in electrostatic lenses. This book then explains the field distribution in magnetic lenses; the optical properties of electrostatic and magnetic lenses; and the similarities and differences between glass optics and electron optics. Subsequent chapters focus on lens defects; some electrostatic lenses and triode guns; and magnetic lens models. The strong focusing lenses and pris

  10. Electronic diagrams

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Diagrams is a ready reference and general guide to systems and circuit planning and in the preparation of diagrams for both newcomers and the more experienced. This book presents guidelines and logical procedures that the reader can follow and then be equipped to tackle large complex diagrams by recognition of characteristic 'building blocks' or 'black boxes'. The goal is to break down many of the barriers that often seem to deter students and laymen in learning the art of electronics, especially when they take up electronics as a spare time occupation. This text is comprised of nin

  11. Digital electronics

    CERN Document Server

    Morris, John

    2013-01-01

    An essential companion to John C Morris's 'Analogue Electronics', this clear and accessible text is designed for electronics students, teachers and enthusiasts who already have a basic understanding of electronics, and who wish to develop their knowledge of digital techniques and applications. Employing a discovery-based approach, the author covers fundamental theory before going on to develop an appreciation of logic networks, integrated circuit applications and analogue-digital conversion. A section on digital fault finding and useful ic data sheets completes th

  12. Electronic identity

    CERN Document Server

    de Andrade, Norberto Nuno Gomes; Argles, David

    2014-01-01

    With the increasing availability of electronic services, security and a reliable means by which identity is verified is essential.Written by Norberto Andrade the first chapter of this book provides an overview of the main legal and regulatory aspects regarding electronic identity in Europe and assesses the importance of electronic identity for administration (public), business (private) and, above all, citizens. It also highlights the role of eID as a key enabler of the economy.In the second chapter Lisha Chen-Wilson, David Argles, Michele Schiano di Zenise and Gary Wills discuss the user-cent

  13. Stretchable electronics

    CERN Document Server

    Someya, Takao

    2012-01-01

    With its comprehensive coverage this handbook and ready reference brings together some of the most outstanding scientists in the field to lay down the undisputed knowledge on how to make electronics stretchable.As such, it focuses on gathering and evaluating the materials, designs, models and technologies that enable the fabrication of fully elastic electronic devices which can sustain high strain. Furthermore, it provides a review of those specific applications that directly benefit from highly compliant electronics, including transistors, photonic devices and sensors. In addition to stre

  14. Starting electronics

    CERN Document Server

    Brindley, Keith

    2005-01-01

    Starting Electronics is unrivalled as a highly practical introduction for hobbyists, students and technicians. Keith Brindley introduces readers to the functions of the main component types, their uses, and the basic principles of building and designing electronic circuits. Breadboard layouts make this very much a ready-to-run book for the experimenter; and the use of multimeter, but not oscilloscopes, puts this practical exploration of electronics within reach of every home enthusiast's pocket. The third edition has kept the simplicity and clarity of the original. New material

  15. Polymer electronics

    CERN Document Server

    Geoghegan, Mark

    2013-01-01

    Polymer electronics is the science behind many important new developments in technology, such as the flexible electronic display (e-ink) and many new developments in transistor technology. Solar cells, light-emitting diodes, and transistors are all areas where plastic electronics is likely to, or is already having, a serious impact on our daily lives. With polymer transistors and light-emitting diodes now being commercialised, there is a clear need for a pedagogic text thatdiscusses the subject in a clear and concise fashion suitable for senior undergraduate and graduate students. The content

  16. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...... technology from kW to MW, discuss which power electronic solutions are most feasible and used today....

  17. Electronic Elections

    DEFF Research Database (Denmark)

    Schürmann, Carsten

    2009-01-01

    Electronic voting technology is a two edged sword. It comes with many risks but brings also many benefits. Instead of flat out rejecting the technology as uncontrollably dangerous, we advocate in this paper a different technological angle that renders electronic elections trustworthy beyond...... the usual levels of doubt. We exploit the trust that voters currently have into the democratic process and model our techniques around that observation accordingly. In particular, we propose a technique of trace emitting computations to record the individual steps of an electronic voting machine...... for a posteriori validation on an acceptably small trusted computing base. Our technology enables us to prove that an electronic elections preserves the voter’s intent, assuming that the voting machine and the trace verifier are independent....

  18. Electronic plants

    Science.gov (United States)

    Stavrinidou, Eleni; Gabrielsson, Roger; Gomez, Eliot; Crispin, Xavier; Nilsson, Ove; Simon, Daniel T.; Berggren, Magnus

    2015-01-01

    The roots, stems, leaves, and vascular circuitry of higher plants are responsible for conveying the chemical signals that regulate growth and functions. From a certain perspective, these features are analogous to the contacts, interconnections, devices, and wires of discrete and integrated electronic circuits. Although many attempts have been made to augment plant function with electroactive materials, plants’ “circuitry” has never been directly merged with electronics. We report analog and digital organic electronic circuits and devices manufactured in living plants. The four key components of a circuit have been achieved using the xylem, leaves, veins, and signals of the plant as the template and integral part of the circuit elements and functions. With integrated and distributed electronics in plants, one can envisage a range of applications including precision recording and regulation of physiology, energy harvesting from photosynthesis, and alternatives to genetic modification for plant optimization. PMID:26702448

  19. ELECTRONIC SIGNATURES

    African Journals Online (AJOL)

    10332324

    'electronic signature' means data attached to, incorporated in, or logically ... See Cwele v S 2012 4 All SA 497 (SCA); Mohlabeng v Minister of Safety and Security ... ZAKZPHC 51 (2 September 2010); Delta Finance, a Division of Wesbank, ...

  20. Electron Microprobe

    Data.gov (United States)

    Federal Laboratory Consortium — The JEOL JXA-8600 is a conventional hairpin filament thermal emission electron microprobe that is more than 20 years old. It is capable of performing qualitative and...

  1. Electronic commerce

    OpenAIRE

    Veselková, Zdeňka

    2012-01-01

    The thesis deals with a description of electronic commerce from its beginning up to present situation in this area. It explains basic terms connected with electronic commerce and it summarizes the relevant legislation. Moreover it describes e-contracts and rights and duties of both contractual parties. The main view is the view of Internet retailer, which is reflected in the practical part focused on concrete problems of retailers.

  2. 华山松大小蠹共生真菌对华山松木质部危害的解剖学研究%Microstructure of blue-stain fungi (Leptographium terebrantis) associated with Dendroctonus armandi in the xylem tissue of Pinus armandi

    Institute of Scientific and Technical Information of China (English)

    陈辉; 唐明

    2002-01-01

    通过对野外和人工接种条件下,华山松大小蠹(Dendroctonus armandi)共生真菌(Leptographium terebrantis)对寄主华山松木质部危害的解剖学研究,结果表明,华山松大小蠹共生真菌随华山松大小蠹入侵健康寄主华山松木质部组织,真菌菌丝首先在其木质部树脂道内发育,分解木质部树脂道泌脂细胞,堵塞树脂道;通过菌丝在木质部交叉场薄壁细胞内及管胞细胞间和管胞细胞内的扩展,使寄主华山松树脂代谢、抗性物质代谢和水分代谢紊乱,木质部边材组织蓝变.

  3. 红脂大小蠹对油松的危害及越冬前后干、根部分布调查%Damage of Dendroctonus valens on Pinus tabulaeformis and its distribution on trunk and root before and after overwintering period

    Institute of Scientific and Technical Information of China (English)

    吴建功; 赵明梅; 张长明; 郭保平; 李建中; 牛璇; 李丽峰; 芦学林

    2002-01-01

    红脂大小蠹Dendroctonus valens Leconte大面积为害油松,造成健康油松大量死亡,在我国尚属首次.选用定点观察和线路踏查相结合的方法,从1999年到2001年5月,对该虫为害油松进行了详细调查.胸径10cm以上的油松受害较重,且胸径越粗受害越重.最细3cm的油松也受害,有虫株率5%~11%,最高达40%,受害株死亡率3.6%,最高达38%.以成虫侵入干基70cm段集中为害,高达180cm.侵入孔流出凝脂.在干部越冬的成虫和幼虫,越冬后死亡.该虫也为害根部,在根部同样可以产卵并发育为成虫,能正常越冬,成为新的扩散虫源.

  4. Molecular Electronics

    DEFF Research Database (Denmark)

    Jennum, Karsten Stein

    This thesis includes the synthesis and characterisation of organic compounds designed for molecular electronics. The synthesised organic molecules are mainly based on two motifs, the obigo(phenyleneethynylenes) (OPE)s and tetrathiafulvalene (TTF) as shown below. These two scaffolds (OPE and TTF......) are chemically merged together to form cruciform-like structures that are an essential part of the thesis. The cruciform molecules were subjected to molecular conductance measurements to explore their capability towards single-crystal field-effect transistors (Part 1), molecular wires, and single electron......, however, was obtained by a study of a single molecular transistor. The investigated OPE5-TTF compound was captured in a three-terminal experiment, whereby manipulation of the molecule’s electronic spin was possible in different charge states. Thus, we demonstrated how the cruciform molecules could...

  5. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    energy at the end-user should also be set up. Deregulation of energy has in the past lowered the investment in larger power plants, which means the need for new electrical power sources will be high in the near future. Two major technologies will play important roles to solve the future problems. One...... is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...

  6. Electron Spectroscopy

    Science.gov (United States)

    Siegbahn, Kai

    Wilhelm Conrad Röntgen's discovery of X radiation in 1895 in Wörzburg resulted in an immediate break-through not only in physics but also in Society, the latter mainly because of its sensational radiological applications. Within a short time it furthermore indirectly led to the discovery of radioactivity by Henri Becquerel. The discovery of X radiation opened the gate to modern atomic physics, and radioactivity to nuclear physics. Later on, the discovery of X-ray diffraction by Laue, Friedrich and Knipping in 1912 initiated the field of X-ray spectroscopy with its fundamental contributions to atomic and crystal structures. Secondary electrons were early observed in the scattered radiation when X-rays were hitting a sample. The development of the corresponding electron spectroscopy had to wait a much longer time for its maturity. A survey of electron spectroscopy is presented.

  7. Electronic Commerce

    Energy Technology Data Exchange (ETDEWEB)

    Laird, N. [NRG Information Services Inc., Calgary, AB (Canada)

    1995-11-01

    The concept of electronic commerce in the gas industry was discussed. It was defined as the integration of communication technology, advanced information processing capability and business standards, to improve effectiveness of the business process. Examples of electronic data interchange from the automotive, airline, and banking industry were given. The objective of using this technology in the gas industry was described as the provision of one electronic facility to make seamless contractual and operational arrangements for moving natural gas across participating pipelines. The benefit of seamless integration - one readily available standard system used by several companies - was highlighted. A list of value-added services such as the free movement of bulletins, directories, nominations,and other documents was provided.

  8. Spin electronics

    CERN Document Server

    Buhrman, Robert; Daughton, James; Molnár, Stephan; Roukes, Michael

    2004-01-01

    This report is a comparative review of spin electronics ("spintronics") research and development activities in the United States, Japan, and Western Europe conducted by a panel of leading U.S. experts in the field. It covers materials, fabrication and characterization of magnetic nanostructures, magnetism and spin control in magnetic nanostructures, magneto-optical properties of semiconductors, and magnetoelectronics and devices. The panel's conclusions are based on a literature review and a series of site visits to leading spin electronics research centers in Japan and Western Europe. The panel found that Japan is clearly the world leader in new material synthesis and characterization; it is also a leader in magneto-optical properties of semiconductor devices. Europe is strong in theory pertaining to spin electronics, including injection device structures such as tunneling devices, and band structure predictions of materials properties, and in development of magnetic semiconductors and semiconductor heterost...

  9. Molecular Electronics

    DEFF Research Database (Denmark)

    Jennum, Karsten Stein

    ) are chemically merged together to form cruciform-like structures that are an essential part of the thesis. The cruciform molecules were subjected to molecular conductance measurements to explore their capability towards single-crystal field-effect transistors (Part 1), molecular wires, and single electron......This thesis includes the synthesis and characterisation of organic compounds designed for molecular electronics. The synthesised organic molecules are mainly based on two motifs, the obigo(phenyleneethynylenes) (OPE)s and tetrathiafulvalene (TTF) as shown below. These two scaffolds (OPE and TTF......, however, was obtained by a study of a single molecular transistor. The investigated OPE5-TTF compound was captured in a three-terminal experiment, whereby manipulation of the molecule’s electronic spin was possible in different charge states. Thus, we demonstrated how the cruciform molecules could...

  10. Greening Electronics

    DEFF Research Database (Denmark)

    Pizzol, Massimo; Søes Kokborg, Morten; Thomsen, Marianne

    Based on a literature review with focus on hazardous substances in waste electric and electronic equipment (WEEE) and numbers from a Danish treatment facility a flow analysis for specific substances has been conducted. Further, the accessible knowledge on human and environmental effects due...

  11. Superconducting electronics

    NARCIS (Netherlands)

    Rogalla, Horst

    1994-01-01

    During the last decades superconducting electronics has been the most prominent area of research for small scale applications of superconductivity. It has experienced quite a stormy development, from individual low frequency devices to devices with high integration density and pico second switching

  12. Electronic Portfolios.

    Science.gov (United States)

    Purves, Alan C.

    1996-01-01

    Outlines three forms of electronic portfolio based on a student's work, a class project about a specific topic, and a class seminar on a broad topic. Discusses logistical problems of management, access, and cross-referencing; technical problems of input, access, and copying; and theoretical issues of the lack of realia, of ownership and copyright,…

  13. Electronic Money.

    Science.gov (United States)

    Schilling, Tim

    Thirty years ago a cashless society was predicted for the near future; paper currency and checks would be an antiquated symbol of the past. Consumers would embrace a new alternative for making payments: electronic money. But currency is still used for 87% of payments, mainly for "nickel and dime" purchases. And checks are the payment…

  14. Electronic spectroscopies

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Schoonheydt, R.A.

    2000-01-01

    Diffuse reflectance spectroscopy (DRS) in the ultraviolet, visible and near-infrared region is a versatile spectroscopic technique, as both d-d and charge transfer transitions of supported TMI can be probed. One of the advantages of electronic spectroscopy is that the obtained information is

  15. Electronic Homework.

    Science.gov (United States)

    Lee, Fong-lok; Heyworth, Rex M.

    The Electronic Homework assistant system is composed of two components: the Computer Tutor and the Homework Administrator. The Computer Tutor is an intelligent tutoring system that can provide personal assistance like supplying hints, checking errors, providing remediation and prioritizing problems. The Homework Administrator is a teacher's…

  16. Greening Electronics

    DEFF Research Database (Denmark)

    Pizzol, Massimo; Søes Kokborg, Morten; Thomsen, Marianne

    Based on a literature review with focus on hazardous substances in waste electric and electronic equipment (WEEE) and numbers from a Danish treatment facility a flow analysis for specific substances has been conducted. Further, the accessible knowledge on human and environmental effects due to po...

  17. Electronic Government

    DEFF Research Database (Denmark)

    Wimmer, Maria A.; Traunmüller, Roland; Grönlund, Åke

    This book constitutes the refereed proceedings of the 4th International Conference on Electronic Government, EGOV 2005, held in Copenhagen, Denmark, in August 2005. The 30 revised papers presented were carefully reviewed and selected from numerous submissions, and assess the state-of-the-art in e...

  18. Electronic detectors for electron microscopy.

    Science.gov (United States)

    Faruqi, A R; McMullan, G

    2011-08-01

    Electron microscopy (EM) is an important tool for high-resolution structure determination in applications ranging from condensed matter to biology. Electronic detectors are now used in most applications in EM as they offer convenience and immediate feedback that is not possible with film or image plates. The earliest forms of electronic detector used routinely in transmission electron microscopy (TEM) were charge coupled devices (CCDs) and for many applications these remain perfectly adequate. There are however applications, such as the study of radiation-sensitive biological samples, where film is still used and improved detectors would be of great value. The emphasis in this review is therefore on detectors for use in such applications. Two of the most promising candidates for improved detection are: monolithic active pixel sensors (MAPS) and hybrid pixel detectors (of which Medipix2 was chosen for this study). From the studies described in this review, a back-thinned MAPS detector appears well suited to replace film in for the study of radiation-sensitive samples at 300 keV, while Medipix2 is suited to use at lower energies and especially in situations with very low count rates. The performance of a detector depends on the energy of electrons to be recorded, which in turn is dependent on the application it is being used for; results are described for a wide range of electron energies ranging from 40 to 300 keV. The basic properties of detectors are discussed in terms of their modulation transfer function (MTF) and detective quantum efficiency (DQE) as a function of spatial frequency.

  19. Electronic Aggression

    Centers for Disease Control (CDC) Podcasts

    2007-11-20

    Aggression is no longer limited to the school yard. New forms of electronic media, such as blogs, instant messaging, chat rooms, email, text messaging, and the internet are providing new arenas for youth violence to occur.  Created: 11/20/2007 by National Center for Injury Prevention and Control, Division of Violence Prevention.   Date Released: 11/28/2007.

  20. Interacting Electrons

    Science.gov (United States)

    Martin, Richard M.; Reining, Lucia; Ceperley, David M.

    2016-06-01

    Preface; Part I. Interacting Electrons: Beyond the Independent-Particle Picture: 1. The many electron problem: introduction; 2. Signatures of electron correlation; 3. Concepts and models for interacting electrons; Part II. Foundations of Theory for Many-Body Systems: 4. Mean fields and auxiliary systems; 5. Correlation functions; 6. Many-body wavefunctions; 7. Particles and quasi-particles; 8. Functionals in many-particle physics; Part III. Many-Body Green's Function Methods: 9. Many-body perturbation theory: expansion in the interaction; 10. Many-body perturbation theory via functional derivatives; 11. The RPA and the GW approximation for the self-energy; 12. GWA calculations in practice; 13. GWA calculations: illustrative results; 14. RPA and beyond: the Bethe-Salpeter equation; 15. Beyond the GW approximation; 16. Dynamical mean field theory; 17. Beyond the single-site approximation in DMFT; 18. Solvers for embedded systems; 19. Characteristic hamiltonians for solids with d and f states; 20. Examples of calculations for solids with d and f states; 21. Combining Green's functions approaches: an outlook; Part IV. Stochastic Methods: 22. Introduction to stochastic methods; 23. Variational Monte Carlo; 24. Projector quantum Monte Carlo; 25. Path integral Monte Carlo; 26. Concluding remarks; Part V. Appendices: A. Second quantization; B. Pictures; C. Green's functions: general properties; D. Matsubara formulation for Green's functions for T ̸= 0; E. Time-ordering, contours, and non-equilibrium; F. Hedin's equations in a basis; G. Unique solutions in Green's function theory; H. Properties of functionals; I. Auxiliary systems and constrained search; J. Derivation of the Luttinger theorem; K. Gutzwiller and Hubbard approaches; References; Index.

  1. ELECTRON GUN

    Science.gov (United States)

    Christofilos, N.C.; Ehlers, K.W.

    1960-04-01

    A pulsed electron gun capable of delivering pulses at voltages of the order of 1 mv and currents of the order of 100 amperes is described. The principal novelty resides in a transformer construction which is disposed in the same vacuum housing as the electron source and accelerating electrode structure of the gun to supply the accelerating potential thereto. The transformer is provided by a plurality of magnetic cores disposed in circumferentially spaced relation and having a plurality of primary windings each inductively coupled to a different one of the cores, and a helical secondary winding which is disposed coaxially of the cores and passes therethrough in circumferential succession. Additional novelty resides in the disposition of the electron source cathode filament input leads interiorly of the transformer secondary winding which is hollow, as well as in the employment of a half-wave filament supply which is synchronously operated with the transformer supply such that the transformer is pulsed during the zero current portions of the half-wave cycle.

  2. Basic electronics

    CERN Document Server

    Tayal, DC

    2010-01-01

    The second edition of this book incorporates the comments and suggestions of my friends and students who have critically studied the first edition. In this edition the changes and additions have been made and subject matter has been rearranged at some places. The purpose of this text is to provide a comprehensive and up-to-date study of the principles of operation of solid state devices, their basic circuits and application of these circuits to various electronic systems, so that it can serve as a standard text not only for universities and colleges but also for technical institutes. This book

  3. Electronic materials

    CERN Document Server

    Kwok, H L

    2010-01-01

    The electronic properties of solids have become of increasing importance in the age of information technology. The study of solids and materials, while having originated from the disciplines of physics and chemistry, has evolved independently over the past few decades. The classical treatment of solid-state physics, which emphasized classifications, theories and fundamental physical principles, is no longer able to bridge the gap between materials advances and applications. In particular, the more recent developments in device physics and technology have not necessarily been driven by new conc

  4. Electronic Router

    Science.gov (United States)

    Crusan, Jason

    2005-01-01

    Electronic Router (E-Router) is an application program for routing documents among the cognizant individuals in a government agency or other organization. E-Router supplants a prior 14 NASA Tech Briefs, May 2005 system in which paper documents were routed physically in packages by use of paper slips, packages could be lost, routing times were unacceptably long, tracking of packages was difficult, and there was a need for much photocopying. E-Router enables a user to create a digital package to be routed. Input accepted by E-Router includes the title of the package, the person(s) to whom the package is to be routed, attached files, and comments to reviewers. Electronic mail is used to notify reviewers of needed actions. The creator of the package can, at any time, see the status of the package in the routing structure. At the end of the routing process, E-Router keeps a record of the package and of approvals and/or concurrences of the reviewers. There are commercial programs that perform the general functions of E-Router, but they are more complicated. E-Router is Web-based, easy to use, and does not require the installation or use of client software.

  5. Modeling Phloem Temperatures Relative to Mountain Pine Beetle Phenology

    OpenAIRE

    Lewis, Matthew Jared

    2011-01-01

    We explore a variety of methods to estimate phloem temperatures from ambient air temperatures suitable for the mountain pine beetle, Dendroctonus ponderosae. A model's ability to induce the same phenology generated from observed phloem temperatures measures its effectiveness rather than a simple reconstruction of phloem temperatures. From a model's phenology results we are able to ascertain whether the model produces a similar amount of developmental energy exhibited by observed phloem temper...

  6. Persistent reduced ecosystem respiration after insect disturbance in high elevation forests

    OpenAIRE

    2013-01-01

    Amid a worldwide increase in tree mortality, mountain pine beetles (Dendroctonus ponderosae Hopkins) have led to the death of billions of trees from Mexico to Alaska since 2000. This is predicted to have important carbon, water and energy balance feedbacks on the Earth system. Counter to current projections, we show that on a decadal scale, tree mortality causes no increase in ecosystem respiration from scales of several square metres up to an 84 km2 valley. Rather, we found comparable declin...

  7. Practical electronics handbook

    CERN Document Server

    Sinclair, Ian R

    2013-01-01

    Practical Electronics Handbook, Third Edition provides the frequently used and highly applicable principles of electronics and electronic circuits.The book contains relevant information in electronics. The topics discussed in the text include passive and active discrete components; linear and digital I.C.s; microprocessors and microprocessor systems; digital-analogue conversions; computer aids in electronics design; and electronic hardware components.Electronic circuit constructors, service engineers, electronic design engineers, and anyone with an interest in electronics will find the book ve

  8. Electronic Preprints

    Science.gov (United States)

    Hanisch, R.

    1999-12-01

    Despite the tremendous advances in electronic publications and the increasing rapidity with which papers are now moving from acceptance into ``print,'' preprints continue to be an important mode of communication within the astronomy community. The Los Alamos e-preprint service, astro-ph, provides for rapid and cost-free (to authors and readers) dissemination of manuscripts. As the use of astro-ph has increased the number of paper preprints in circulation to libraries has decreased, and institutional preprint series appear to be waning. It is unfortunate, however, that astro-ph does not function in collaboration with the refereed publications. For example, there is no systematic tracking of manuscripts from preprint to their final, published form, and as a centralized archive it is difficult to distribute the tracking and maintenance functions. It retains documents that have been superseded or have become obsolete. We are currently developing a distributed preprint and document management system which can support both distributed collections of preprints (e.g., traditional institutional preprint series), can link to the LANL collections, can index other documents in the ``grey'' literature (observatory reports, telescope and instrument user's manuals, calls for proposals, etc.), and can function as a manuscript submission tool for the refereed journals. This system is being developed to work cooperatively with the refereed literature so that, for example, links to preprints are updated to links to the final published papers.

  9. Sustainable Management of Electronics

    Science.gov (United States)

    To provide information on EPAs strategy for electronics stewardship, certified electronics recyclers and the Challenge; as well as where to donate unwanted electronics, how to calculate benefits, and what's going on with electronics mgmt in their states.

  10. EDITORIAL: Synaptic electronics Synaptic electronics

    Science.gov (United States)

    Demming, Anna; Gimzewski, James K.; Vuillaume, Dominique

    2013-09-01

    Conventional computers excel in logic and accurate scientific calculations but make hard work of open ended problems that human brains handle easily. Even von Neumann—the mathematician and polymath who first developed the programming architecture that forms the basis of today's computers—was already looking to the brain for future developments before his death in 1957 [1]. Neuromorphic computing uses approaches that better mimic the working of the human brain. Recent developments in nanotechnology are now providing structures with very accommodating properties for neuromorphic approaches. This special issue, with guest editors James K Gimzewski and Dominique Vuillaume, is devoted to research at the serendipitous interface between the two disciplines. 'Synaptic electronics', looks at artificial devices with connections that demonstrate behaviour similar to synapses in the nervous system allowing a new and more powerful approach to computing. Synapses and connecting neurons respond differently to incident signals depending on the history of signals previously experienced, ultimately leading to short term and long term memory behaviour. The basic characteristics of a synapse can be replicated with around ten simple transistors. However with the human brain having around 1011 neurons and 1015 synapses, artificial neurons and synapses from basic transistors are unlikely to accommodate the scalability required. The discovery of nanoscale elements that function as 'memristors' has provided a key tool for the implementation of synaptic connections [2]. Leon Chua first developed the concept of the 'The memristor—the missing circuit element' in 1971 [3]. In this special issue he presents a tutorial describing how memristor research has fed into our understanding of synaptic behaviour and how they can be applied in information processing [4]. He also describes, 'The new principle of local activity, which uncovers a minuscule life-enabling "Goldilocks zone", dubbed the

  11. Electronic Mimosa

    Science.gov (United States)

    Gupta, Sanjay; Datta, Meera S.; Rana, Vivek; Grover, Shailesh

    1996-04-01

    This paper describes the design of a low-cost, 2D, electromagnetic tracking device for personal computers. This interface makes use of the well-known principle of electromagnetic induction to locate the position of a transmitter in an x-y plane. This device has a ring which is worn by the user on the index finger. The computer monitor is overlaid with a transparent screen equipped with tuned electromagnetic sensors. These sensors pick up the signals transmitted by the transmitter coil on the finger. The receiver circuit extracts the envelope of the received signal and digitizes it. These digitized values of x and y axis signals are read by the computer through the standard parallel port. The system software running on the computer calculates the x and y co-ordinates of the transmitter coil and displays a cursor at that location. The transmitter also has a button which can be used like a mouse button. This keypress information is also transmitted by the electromagnetic means. The device driver for this tracker replaces the standard mouse driver. Hence most applications which use a mouse can also use this tracker. Its name `Mimosa' indicates that the user need not touch the screen (Mimosa Pudica is the Latin name of a plant whose leaves wilt when touched). Presently work is on to achieve uniform sensitivity over the entire screen and reducing transmitter power consumption. In order to demonstrate its working, a small, 3D game was written. The player has to reach a pre-defined location after traversing through a maze. The paper describes the interface electronics, system software, mechanical design and the sample application.

  12. Carbon Nanotube Electron Gun

    Science.gov (United States)

    Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)

    2013-01-01

    An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

  13. Mapping the infestation of Dendroctonus armandi in Shennongjia forested region using Landsat and MaxEnt model%基于最大熵模型的神农架林区华山松大小蠹灾害遥感监测

    Institute of Scientific and Technical Information of China (English)

    马望; 房磊; 方国飞; 于跃; 张旭; 杨健

    2016-01-01

    掌握森林病虫害的发生范围和危害程度,对于森林管理部门制定及时、有效的防治决策至关重要.本研究以2014年湖北省神农架林区华山松大小蠹(Dendroctonus armandi)灾害为背景,以野外调查数据、多光谱陆地资源卫星影像(Landsat)和数字高程模型(DEM)为基础数据源,结合最大熵(MaxEnt)模型和迭代阈值分割算法,提出了适用于复杂林区的森林病虫害遥感监测方法(MaxEnt-Segmentation),实现了神农架林区华山松大小蠹灾害空间分布范围和灾害程度的专题制图与精度评价.同时,为衡量所提出方法对于灾害程度评估的可靠性与准确度,本文还与传统光谱指数分析法进行了对比研究.结果表明:结合遥感光谱指数、海拔、坡度及有效太阳辐射等环境因子构建的MaxEnt模型能够较为准确地监测华山松大小蠹灾害发生范围,受试者工作特征曲线下面积(AUC)值为0.938;当分类类型包括健康、轻度和重度时,MaxEnt-Segmentation法分类精度最高达73.68%,明显高于传统光谱指数分析法(64.47%),表明该算法能够提高森林虫灾监测精度,适合用于植被类型多样、地形复杂林区的病虫害遥感监测.

  14. Anatomical characteristics in xylem tissue of Pinus armandi infected by the bark beetle Dendroctonus armandi(Coleoptera: Scolytidae) and its associated blue-stain fungus Ceratocystis polonica%华山松大小蠹及其伴生蓝变真菌对华山松木质部危害的解剖学特征

    Institute of Scientific and Technical Information of China (English)

    谢寿安; 吕淑杰; Axel SHOPF2; 丁彦; 侯秋实; 李彩棉

    2008-01-01

    为揭示华山松大小蠹和伴生蓝变真菌引起秦岭华山松枯萎的机制,选择秦岭北坡沣峪林场境35年树龄的健康华山松Pinus armandi为研究对象,对接种华山松大小蠹Dendroctonus armandi及与其伴生的蓝变真菌Ceratocystis polonica引起的寄主树木木质部形态变化进行了解剖观察.结果表明:接种致病性蓝变真菌C.polonica 1周后的4株华山松的木质部组织内,蓝变区域显著增加.4~6周后蓝变区域不再增加;而在接种无菌琼脂的2株对照华山松的木质部组织内,没有检测到蓝变区域.研究结果提示蓝变真菌C.polonica,是致死秦岭华山松的重要病原菌,该伴生菌随华山松大小蠹入侵健康寄主华山松木质部组织,在木质部定居并分解木质部,堵塞树脂道,致使寄主华山松树脂代谢和水分代谢紊乱.该研究结果表明,虽然华山松大小蠹长期以来被认为是致死华山松的毁灭性小蠹虫,但是其共生蓝变真菌C.polonnica对成熟华山松的致害作用不应该被忽视.

  15. 红脂大小蠹后肠挥发性物质的鉴定、触角电位和室内趋向实验%Identification and electroantennal olfactory and behavioral tests of hindgut-produced volatiles of the red turpentine beetle, Dendroctonus valens LeConte( Coleoptera:Scolytidae)

    Institute of Scientific and Technical Information of China (English)

    闫争亮; 方宇凌; 孙江华; 张钟宁

    2004-01-01

    对外来松树害虫红脂大小蠹Dendroctonus valens LeConte的信息化学物质进行了研究.通过GC-MS测定,鉴定出红脂大小蠹后肠挥发性物质中,除了含有松树挥发性物质α-蒎烯、β-蒎烯、3-蒈烯、月桂烯和柠檬烯外,还含有马鞭草烯醇和马鞭草烯酮;利用触角电位技术,对马鞭草烯醇、马鞭草烯酮以及在林间引诱效果最好的3-(+)-蒈烯进行了触角电生理测试;利用Y-型双向选择嗅觉仪对这些物质进行了室内趋向实验.实验结果表明:1 μg的马鞭草烯醇、马鞭草烯酮和3-(+)-蒈烯引起雌雄触角的电位反应分别达416 μV/470 μV、597 μV/630 μV和926 μV/1 099 μV.浓度为1 μL/mL的马鞭草烯酮引起红脂大小蠢的正趋向反应,而在100 μL/mL浓度下引起红脂大小蠹的负趋向反应;在1 μL/mL的浓度下,3-(+)-蒈烯引起了红脂大小蠹正趋向反应,而马鞭草烯醇则对红脂大小蠹具有驱避作用,说明这些物质在红脂大小蠹搜寻寄主和调节虫口密度方面起着重要作用.

  16. Nano-Electronics and Bio-Electronics

    Science.gov (United States)

    Srivastava, Deepak; Kwak, Dochan (Technical Monitor)

    2001-01-01

    Viewgraph presentation on Nano-Electronics and Bio-Electronics is discussed. Topics discussed include: NASA Ames nanotechnology program, Potential Carbon Nanotube (CNT) application, CNT synthesis,Computational Nanotechnology, and protein nanotubes.

  17. Electronics for LHC Experiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This document gathers the abstracts of most presentations made at this workshop on electronics for the large hadron collider (LHC) experiments. The presentations were arranged into 6 sessions: 1) electronics for tracker, 2) trigger electronics, 3) detector control systems, 4) data acquisition, 5) electronics for calorimeters and electronics for muons, and 6) links, power systems, grounding and shielding, testing and quality assurance.

  18. Interface Electronic Circuitry for an Electronic Tongue

    Science.gov (United States)

    Keymeulen, Didier; Buehler, Martin

    2007-01-01

    Electronic circuitry has been developed to serve as an interface between an electronic tongue and digital input/output boards in a laptop computer that is used to control the tongue and process its readings. Electronic tongues can be used for a variety of purposes, including evaluating water quality, analyzing biochemicals, analyzing biofilms, and measuring electrical conductivities of soils.

  19. 一种红脂大小蠹天敌切头郭公虫Clerus sp.生物学初探%Biological study of the decapitator checkered beetle Clerus sp.,a natural enemy of the invasive bark beetle Dendroctonus valens

    Institute of Scientific and Technical Information of China (English)

    王海河; 董刚毅; 徐冰冰; 刘柱东

    2013-01-01

    The red turpentine beetle Dendroctonus valens LeConte,native to North America,is one of the most destructive invasive forest pests in China,having killed more than 6 million pine trees since its first outbreak in 1999.Most research has focused on the chemical communication of this species and relatively little is known about its natural enemies.In this paper we investigate the potential of using the decapitator checkered beetle (Clerus spp.) to control the red turpentine beetle.Field trapping showed that Clerus sp.is attracted to a lure (3-carene) extracted from D.valens and that some D.valens bark beetles were decapitated.Moreover,decapitator beetles took flight out about one week after the flight of D.valens and its numbers were correlated with those of D.valens.Laboratory experiments showed that decapitator beetles weigh about 15.5 mg on average and that its predatory capability was significantly correlated with its body weight.Decapitators survived,on average,38 d and the longest-lived survived 53 d,and could prey on an average of three D.valens adults per 10 days (range 1 to 8 individuals).Olfactory assays showed that decapitator beetles were attracted to a lure for D.valens and that the D.valens aggregation pheromone frontalin did not increase the attractiveness of the lure.These results show the potential of using Clerus sp.to biologically control the invasive bark beetle D.valens in China.%红脂大小蠹Dendroctonus valens LeConte,原产于北美,于20世纪80年代随木材贸易传入我国山西,是一种危害油松、白皮松、华山松等松科植物的毁灭性入侵害虫.本文对红脂大小蠹天敌切头郭公甲虫Clerus sp.的基本生物学特征进行了初步探讨.野外诱捕发现,红脂大小蠹诱剂3-蒈烯能诱捕到切头郭公甲虫Clerus sp.,并观察到此郭公甲虫紧抱红脂大小蠹的捕食行为及红脂大小蠹头部被切下的残骸.诱捕动态监测表明切头郭公甲虫与红脂大小蠹的发生在时间和

  20. Electron beam focusing system

    Energy Technology Data Exchange (ETDEWEB)

    Dikansky, N.; Nagaitsev, S.; Parkhomchuk, V.

    1997-09-01

    The high energy electron cooling requires a very cold electron beam. Thus, the electron beam focusing system is very important for the performance of electron cooling. A system with and without longitudinal magnetic field is presented for discussion. Interaction of electron beam with the vacuum chamber as well as with the background ions and stored antiprotons can cause the coherent electron beam instabilities. Focusing system requirements needed to suppress these instabilities are presented.

  1. Electronics and Information

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Previously founded as CCPITMachinery and Electronics Sub-council and CCOIC Machinery and Electronics Chamber of Corn-merce in June, 1988, CCPIT Electronics Sub-Council and CCOIC Electronics Chamber of Commerce were established in May, 1993, and then renamed as CCPIT Electronics and Information Industry Sub-council and CCOIC Electronics and Infor-mation Industry Chamber of Commerce (CCPITECC) in September 1999.

  2. Electronic Correlations in Electron Transfer Systems

    Science.gov (United States)

    Bulla, Ralf; Tornow, Sabine; Anders, Frithjof

    Electron transfer processes play a central role in many chemical and biological systems. Already the transfer of a single electron from the donor to the acceptor can be viewed as a complicated many-body problem, due to the coupling of the electron to the infinitely many environmental degrees of freedom, realized by density fluctuations of the solvent or molecular vibrations of the protein matrix. We focus on the quantum mechanical modelling of two-electron transfer processes whose dynamics is governed by the Coulomb interaction between the electrons as well as the environmental degrees of freedoms represented by a bosonic bath. We identify the regime of parameters in which concerted transfer of the two electrons occurs and discuss the influence of the Coulomb repulsion and the coupling strength to the environment on the electron transfer rate. Calculations are performed using the non-perturbative numerical renormalization group approach for both equilibrium and non-equilibrium properties.

  3. Electron Microscopy Center (EMC)

    Data.gov (United States)

    Federal Laboratory Consortium — The Electron Microscopy Center (EMC) at Argonne National Laboratory develops and maintains unique capabilities for electron beam characterization and applies those...

  4. Investigations on Electronic Materials

    OpenAIRE

    E. Pugnor; T. Kormány

    1982-01-01

    Electronics has been described as a materials oriented technology. In this sense a short review is given concerning: the connection of materials characterization to the design and processing of electronic components; the most important materials characterization methods used for electronic materials; the strategy of organizing a complete material characterization system for selected electronic components.

  5. Electron-attachment processes

    Science.gov (United States)

    Christophorou, L. G.; McCorkle, D. L.; Christodoulides, A. A.

    Topics covered include: modes of production of negative ions, techniques for the study of electron attachment processes, dissociative electron attachment to ground state molecules, dissociative electron attachment to hot molecules (effects of temperature on dissociative electron attachment), molecular parent negative ions, and negative ions formed by ion pair processes and by collisions of molecules with ground state and Rydberg atoms.

  6. Electronic Health Records

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Electronic Health Records KidsHealth > For Teens > Electronic Health Records Print A A A What's in ... t happen overnight, they are coming. Understanding EHRs Electronic health records (EHR) — also called electronic medical records ( ...

  7. Introduction to electronics

    CERN Document Server

    CERN. Geneva

    2005-01-01

    Electronics in HEP experiments: specificities and evolution The Art of Electronics: is there something beyond Ohm's law? Basic building blocks of Analog electronics: quickly understanding a schematic Charge preamps, current preamps and future preamps, shaping and the rest Electronics noise: fundamental and practical Evolution of technology: ASICs, FPGAs...

  8. Introduction to Electronics course

    CERN Document Server

    CERN. Geneva HR-RFA

    2006-01-01

    Electronics in HEP experiments: specificities and evolution The Art of Electronics: is there something beyond Ohm's law? Basic building blocks of Analog electronics: quickly understanding a schematic Charge preamps, current preamps and future preamps, shaping and the rest Electronics noise: fundamental and practical Evolution of technology: ASICs, FPGAs...

  9. Electronic Health Records

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Electronic Health Records KidsHealth > For Teens > Electronic Health Records A A A What's in this ... t happen overnight, they are coming. Understanding EHRs Electronic health records (EHR) — also called electronic medical records ( ...

  10. Introduction to Electronic Marketing.

    Science.gov (United States)

    Dilbeck, Lettie

    These materials for a five-unit course were developed to introduce secondary and postsecondary students to the use of electronic equipment in marketing. The units cover the following topics: electronic marketing as a valid marketing approach; telemarketing; radio electronic media marketing; television electronic media marketing; and cable TV…

  11. Hybrid printed electronics

    NARCIS (Netherlands)

    Koetse, M.; Smits, E.; Rubingh, E.; Teunissen, P.; Kusters, R.; Abbel, R.; Brand, J. van den

    2016-01-01

    Although many electronic functionalities can be realized by printed or organic electronics, short-term marketable products often require robust, reproducible, and nondisturbing technologies. In this chapter we show how hybrid electronics, a combination of printed circuitry, thin-film electronics,

  12. Electron transfer reactions

    CERN Document Server

    Cannon, R D

    2013-01-01

    Electron Transfer Reactions deals with the mechanisms of electron transfer reactions between metal ions in solution, as well as the electron exchange between atoms or molecules in either the gaseous or solid state. The book is divided into three parts. Part 1 covers the electron transfer between atoms and molecules in the gas state. Part 2 tackles the reaction paths of oxidation states and binuclear intermediates, as well as the mechanisms of electron transfer. Part 3 discusses the theories and models of the electron transfer process; theories and experiments involving bridged electron transfe

  13. Electronics engineer's reference book

    CERN Document Server

    Mazda, F F

    1989-01-01

    Electronics Engineer's Reference Book, Sixth Edition is a five-part book that begins with a synopsis of mathematical and electrical techniques used in the analysis of electronic systems. Part II covers physical phenomena, such as electricity, light, and radiation, often met with in electronic systems. Part III contains chapters on basic electronic components and materials, the building blocks of any electronic design. Part IV highlights electronic circuit design and instrumentation. The last part shows the application areas of electronics such as radar and computers.

  14. Practical microwave electron devices

    CERN Document Server

    Meurant, Gerard

    2013-01-01

    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  15. Electronics engineer's reference book

    CERN Document Server

    Turner, L W

    1976-01-01

    Electronics Engineer's Reference Book, 4th Edition is a reference book for electronic engineers that reviews the knowledge and techniques in electronics engineering and covers topics ranging from basics to materials and components, devices, circuits, measurements, and applications. This edition is comprised of 27 chapters; the first of which presents general information on electronics engineering, including terminology, mathematical equations, mathematical signs and symbols, and Greek alphabet and symbols. Attention then turns to the history of electronics; electromagnetic and nuclear radiatio

  16. 加拿大哥伦比亚省美国黄松广义代数差分型地位指数模型%Generalized Algebraic Difference Site Index Model for Ponderosa Pine in British Columbia, Canada

    Institute of Scientific and Technical Information of China (English)

    赵磊; 倪成才; Gordon Nigh

    2012-01-01

    基于3种常用的理论生长模型,利用代数差分法和广义代数差分法推导8个差分型地位指数模型.模型拟合采用加拿大哥伦比亚省美国黄松林分79个临时样地的纵向剖面解析木数据和分类变量回归的参数估计方法,模型筛选采用统计指标和图形分析相结合的方法,并着重突出了图形分析的重要性;同时,本文对于最佳模型的应用也进行了较为全面的分析研究.结果表明:1)广义差分型地位指数模型具有更高的预测性能;2)基于Hossfeld IV生长模型的广义差分型地位指数模型表现出了最佳的性能,推荐采用该模型对加拿大哥伦比亚省30~200年的美国黄松林分进行树高生长预测和立地质量分类;3)依据预测的相对误差,确定100年为最佳指数年龄.%Based upon 3 widely used base models, a total of 8 ADA/GADA site index models were derived. The data for these models in this study were obtained from 79 pith-split stem analysis plots and the estimation method was "indicator variable approach". We used both fit statistics and visual analysis to select the best-fit model, and attached more importance to the visual analysis. A comprehensive application analysis was also given to the selected model. The results showed; 1) GADA outperformed ADA with respect to predictions. 2) A GADA model derived from Hossfeld IV presented the best prediction ability. It was suggested that the model be used to predict dominant height and to estimate site index for ponderosa pine stands ranging 30 -200 years in British Columbia, Canada. 3 ) The best site index age was age of 100 years, based upon relative errors of predictions.

  17. Single electron-ics with carbon nanotubes

    NARCIS (Netherlands)

    Götz, G.T.J.

    2010-01-01

    We experimentally investigate Quantum Dots, formed in Carbon Nanotubes. The first part of this thesis deals with charge sensing on such quantum dots. The charge sensor is a metallic Single-electron-transistor, sensitive to the charge of a single electron on the quantum dot. We use this technique for

  18. Electron-electron interactions in disordered systems

    CERN Document Server

    Efros, AL

    1985-01-01

    ``Electron-Electron Interactions in Disordered Systems'' deals with the interplay of disorder and the Coulomb interaction. Prominent experts give state-of-the-art reviews of the theoretical and experimental work in this field and make it clear that the interplay of the two effects is essential, especially in low-dimensional systems.

  19. VIRTUAL ELECTRONIC COMPONENTS OF THE ELECTRONIC EQUIPMENT

    Directory of Open Access Journals (Sweden)

    E. Lazarevich

    2013-01-01

    Full Text Available The article is present new idea of the creation, developments and improvements of the electronic equipment of complex systems by means of the virtual electronic components. The idea of the virtual electronic components is a presentation and perception of the creation and developments of the equipment on two forming: real – in the manner of standard marketed block of the intellectual property and image – in the manner of virtual component. The real component in most cases slows the development of the electronic equipment. The imaginary component is the «locomotive» of development of the electronic equipment. The Imaginary component contains the scientific has brushed against developer. The scientific has brushed against developer reveals of itself in the manner of virtual component on the modern level of the design rates of microelectronics.

  20. Electron transporting semiconducting polymers in organic electronics.

    Science.gov (United States)

    Zhao, Xingang; Zhan, Xiaowei

    2011-07-01

    Significant progress has been achieved in the preparation of semiconducting polymers over the past two decades, and successful commercial devices based on them are slowly beginning to enter the market. However, most of the conjugated polymers are hole transporting, or p-type, semiconductors that have seen a dramatic rise in performance over the last decade. Much less attention has been devoted to electron transporting, or n-type, materials that have lagged behind their p-type counterparts. Organic electron transporting materials are essential for the fabrication of organic p-n junctions, organic photovoltaic cells (OPVs), n-channel organic field-effect transistors (OFETs), organic light-emitting diodes (OLEDs) and complementary logic circuits. In this critical review we focus upon recent developments in several classes of electron transporting semiconducting polymers used in OLEDs, OFETs and OPVs, and survey and analyze what is currently known concerning electron transporting semiconductor architecture, electronic structure, and device performance relationships (87 references).