The ceo-geographical division of forest insects in China is generally divided into 4 levels: region, subrcgion, area and province. The region is formed by isolation of ocean, high mountain and desert etc. The division...The ceo-geographical division of forest insects in China is generally divided into 4 levels: region, subrcgion, area and province. The region is formed by isolation of ocean, high mountain and desert etc. The division of subrcgion is on the basis of resistance of extreme temperature humidity in winter. The division of area or province is on the basis of landform, type of vegetation in forest zone and temperature zone.展开更多
In China the research in the phusiology of forest in inseets began in the 1970s,and in the 1980s a great deal of research works was done in this field,a lot of which were concen-trated on the isolation,identification ...In China the research in the phusiology of forest in inseets began in the 1970s,and in the 1980s a great deal of research works was done in this field,a lot of which were concen-trated on the isolation,identification and synthesis of sex pheromones on the injurious forest in-seets with in Lepidopteron and Coleopteron.In the field of tree resistance physiology,some ad-vanees were achieved in the resislance mechanism of poplar to Longicorn beetles and prominents.The research of the resistance of plne to Matsucoccusmalsumurae Kuwana is now also going on.In addition,the seductive function of plant sex seducements to the Longicorn bee-tle and its digestion physiology are also being studied.Many reports on the analysis of proteins,isoenzymes and amino acids applied to classification of Longicorn beetles,Pine moths and Aphids have been published.A relatively deep insight was gained in the physiological characters of overwintering larvae of Coleophoradahuriea Flkv.in the deep cold region of Hellongjiang展开更多
Under global climate change,high and low temperature extremes can drive shifts in species distributions.Across the range of a species,thermal tolerance is based on acclimatization,plasticity,and may undergo selection,...Under global climate change,high and low temperature extremes can drive shifts in species distributions.Across the range of a species,thermal tolerance is based on acclimatization,plasticity,and may undergo selection,shaping resilience to temperature stress.In this study,we measured variation in cold temperature tolerance of early instar larvae of an invasive forest insect,Lymantria dispar dispar L.(Lepidoptera:Erebidae),using populations sourced from a range of climates within the current introduced range in the Eastern United States.We tested for population differences in chill coma recovery(CCR)by measuring recovery time following a period of exposure to a nonlethal cold temperature in 2 cold exposure experiments.A 3rd experiment quantified growth responses after CCR to evaluate sublethal effects.Our results indicate that cold tolerance is linked to regional climate,with individuals from populations sourced from colder climates recovering faster from chill coma.While this geographic gradient is seen in many species,detecting this pattern is notable for an introduced species founded from a single point-source introduction.We demonstrate that the cold temperatures used in our experiments occur in nature during cold spells after spring egg hatch,but impacts to growth and survival appear low.We expect that population differences in cold temperature performance manifest more from differences in temperature-dependent growth than acute exposure.Evaluating intraspecific variation in cold tolerance increases our understanding of the role of climatic gradients on the physiology of an invasive species,and contributes to tools for predicting further expansion.展开更多
An investigation method with sample plots was used to study insect communities in four different growth phases of natural Populus euphratica forests, which are juvenile, middle aged, over-mature and degraded forests, ...An investigation method with sample plots was used to study insect communities in four different growth phases of natural Populus euphratica forests, which are juvenile, middle aged, over-mature and degraded forests, in Tarim, Xinjiang in July, 2005 and April, 2006. In our studies, 5,116 insect specimens, belonging to 12 orders, 61 families and 141 species, were collected. Lepidoptera and Coleoptera were the dominant orders. In middle-aged forests, species, individual numbers and diversity indices of insect com-munities were higher than those in other woodlands. The species richness and diversity indices were lowest in degraded forests be-cause of extremely scarce vegetation.展开更多
Eleven species of alien invasive forest insect pests have been found since the early time that insect species had been taken recorded in China. Their origins, inland distribution, invasive time, hosts, causing damage ...Eleven species of alien invasive forest insect pests have been found since the early time that insect species had been taken recorded in China. Their origins, inland distribution, invasive time, hosts, causing damage are recorded in this paper for the evidence of biological invasion. Their control methods are also studied or discussed.展开更多
Insects respond to changes in microhabitat caused by canopy disturbance, and thus can be used to examine the ecological impacts of harvesting. Single-tree selection harvesting is the most common silvicultural system u...Insects respond to changes in microhabitat caused by canopy disturbance, and thus can be used to examine the ecological impacts of harvesting. Single-tree selection harvesting is the most common silvicultural system used to emulate local small-scale natural disturbance and maintain uneven-aged forest structure in temperate forests. Here, we test for differences in richness, abundance, and composition of hymenopteran and saproxylic insect assemblages at four different taxon levels （selected insect orders; and all hymenopteran families, and braconid subfamilies and morphospecies） between the canopy and understory of unharvested and single-tree selection harvested sites in a northern temperate forest from central Canada. Harvesting had no effect on insect assemblage richness, composition or abundance at the three highest taxon levels （order, family and subfamily）. Similarly, richness and abundance at the lowest-taxon level （braconid morphospecies） were similar, although composition differed slightly between unharvested and harvested stands. Insect assemblages were vertically stratified, with generally higher abundance （for Diptera, Hymenoptera, some hymenopteran families and braconid subfamilies） and richness （for braconid morphospecies） in the understory than the canopy. In particular, composition of the braconid morphospecies assemblage showed relatively low similarity between the understory and canopy. Single-tree selection harvesting appears to influence wood-associated insect taxa only subtly through small changes in community composition at the lowest taxon level, and thus is recommended as a conservative approach for managing these northern temperate forests.展开更多
Saproxylic insect assemblages are essential functional components of forest ecosystems that can be affected by forest management.We used a split-plot ANOVA design to analyze differences in selected saproxylic insects...Saproxylic insect assemblages are essential functional components of forest ecosystems that can be affected by forest management.We used a split-plot ANOVA design to analyze differences in selected saproxylic insects（all arthropod orders and dipteran and parasitic hymenopteran families） emerging from dead wood of sites with different logging histories（horse-logged,mechanically-logged and unlogged）,tree species（Populus and Picea）,stage of decay（early-and late-decay stages） and posture（standing and downed logs） in the boreal forest of central Canada.No clear effects of logging history were seen for the studied taxa; however,interaction between logging history and other dead wood features was apparent.Cecidomyiidae consistently emerged more from Populus than from Picea dead wood.Most of the studied saproxylic families were more abundant in late-decay than in early-decay wood.Dipterans of the Cecidomyiidae,Ceratopogonidae,Empididae,Mycetophilidae and Sciaridae families,and hymenopterans of the Diapriidae and Ichneumonidae families were significantly more abundant in downed than in standing dead wood.In contrast,Mymaridae was most abundant in standing dead wood.Our study provides evidence that some insects at high taxonomic levels respond differently to dead wood quality,and this could inform future management strategies in the boreal forest for the conservation of saproxylic fauna and their ecological functions.展开更多
Using tree-ring analysis, we show that the dynamics of forest tent caterpillar [Malacosoma disstria (Hbn.)] outbreaks in Alberta, Canada shifted at the turn of the 20th century from cyclic, synchronous behaviour 1850-...Using tree-ring analysis, we show that the dynamics of forest tent caterpillar [Malacosoma disstria (Hbn.)] outbreaks in Alberta, Canada shifted at the turn of the 20th century from cyclic, synchronous behaviour 1850-1910 to complex, asynchronous behavior 1910-1993. This shift in dynamics coincided with the emergence in 1910 of a latitudinal gradient in outbreak stability and periodicity reflecting a similar gradient in the periodicity of winter temperatures. We postulate that the synchronizing strength of winter temperatures has diminished as a result of climate warming, and that any synchronizing strength due to inter-population migration has been superseded by regionalized patterns of periodic forcing caused by weak low-frequency variability in winter temperatures. We speculate that a decrease in polar vorticity at the start of the 20th century led to increased meridional jet stream flow and more frequent arctic weather anomalies, resulting in a loss of synchronous decadal periodicity in outbreak occurrence. These changes in insect disturbance probabilities, including rising uncertainty, have profound consequences for forest disturbance risk management.展开更多
Assessing carbon (C) sequestration in forest ecosystems is fundamental to supply information to monitoring, reporting and verification (MRV) for reducing deforestation and forest degradation (REDD). The spatially-expl...Assessing carbon (C) sequestration in forest ecosystems is fundamental to supply information to monitoring, reporting and verification (MRV) for reducing deforestation and forest degradation (REDD). The spatially-explicit version of Forest-DNDC (FDNDC) was evaluated using plot-based observations from Nez Perce-Clearwater National Forest (NPCNF) in Idaho of United States and used to assess C stocks in?about 16,000 km2. The model evaluation indicated that the FDNDC can be used to assess C stocks with disturbances in this temperate forest with a proper model performance efficiency and small error between observations and simulations. Aboveground biomass in this forest was 85.1 Mg C ha-1 in 2010. The mean aboveground biomass in the forest increased by about 0.6 Mg C ha-1 yr-1 in the last 20 years from 1990 to 2010 with spatial mean stand age about 98 years old in 2010. Spatial differences in distributions of biomass, net primary production and net ecosystem product are substantial. The spatial divergence in C sequestration is mainly associated with the spatial disparities in stand age due to disturbances, secondly with ecological drivers and species. Climate variability and change can substantially impact C stocks in the forest based on the climatic variability of spatial climate data for a 33-year period from 1981 to 2013. Temperature rise can produce more biomass in NPCNF, but biomass cannot increase with an increase in precipitation in this forest. The simulation with disturbances using observations and estimates for the time period from 1991 to 2011?showed the effects of disturbances on C stocks in forests. The impacts of fires and insects on C stocks in this forest are highly dependent on the severity, the higher, the more C loss to atmosphere due to?fires, and the more dead woods produced by fires and insects. The rates of biomass increase with an increase in stand age are different among the species. The changes in forest C stocks?in the forest are almost species specific, non-linear and complex. The increase in aboveground biomass with an increase in stand age can be described by a high-order polynomial.展开更多
文摘The ceo-geographical division of forest insects in China is generally divided into 4 levels: region, subrcgion, area and province. The region is formed by isolation of ocean, high mountain and desert etc. The division of subrcgion is on the basis of resistance of extreme temperature humidity in winter. The division of area or province is on the basis of landform, type of vegetation in forest zone and temperature zone.
文摘In China the research in the phusiology of forest in inseets began in the 1970s,and in the 1980s a great deal of research works was done in this field,a lot of which were concen-trated on the isolation,identification and synthesis of sex pheromones on the injurious forest in-seets with in Lepidopteron and Coleopteron.In the field of tree resistance physiology,some ad-vanees were achieved in the resislance mechanism of poplar to Longicorn beetles and prominents.The research of the resistance of plne to Matsucoccusmalsumurae Kuwana is now also going on.In addition,the seductive function of plant sex seducements to the Longicorn bee-tle and its digestion physiology are also being studied.Many reports on the analysis of proteins,isoenzymes and amino acids applied to classification of Longicorn beetles,Pine moths and Aphids have been published.A relatively deep insight was gained in the physiological characters of overwintering larvae of Coleophoradahuriea Flkv.in the deep cold region of Hellongjiang
基金conducted under USDA APHIS permit numbers P526P-17-03681 and P526P-20-02026(K.L.G.)and P526P-16-04388(D.P.)supported by the National Science Foundation under Grant DEB 1702701(K.L.G.)and 1702312(D.P.)under the Macrosystems Biology Program and the Thomas F.and Kate Miller Jeffress Memorial Trust+1 种基金funding was provided by the Slow-the-Spread Foundationthe University of Richmond School of Arts&Sciences.
文摘Under global climate change,high and low temperature extremes can drive shifts in species distributions.Across the range of a species,thermal tolerance is based on acclimatization,plasticity,and may undergo selection,shaping resilience to temperature stress.In this study,we measured variation in cold temperature tolerance of early instar larvae of an invasive forest insect,Lymantria dispar dispar L.(Lepidoptera:Erebidae),using populations sourced from a range of climates within the current introduced range in the Eastern United States.We tested for population differences in chill coma recovery(CCR)by measuring recovery time following a period of exposure to a nonlethal cold temperature in 2 cold exposure experiments.A 3rd experiment quantified growth responses after CCR to evaluate sublethal effects.Our results indicate that cold tolerance is linked to regional climate,with individuals from populations sourced from colder climates recovering faster from chill coma.While this geographic gradient is seen in many species,detecting this pattern is notable for an introduced species founded from a single point-source introduction.We demonstrate that the cold temperatures used in our experiments occur in nature during cold spells after spring egg hatch,but impacts to growth and survival appear low.We expect that population differences in cold temperature performance manifest more from differences in temperature-dependent growth than acute exposure.Evaluating intraspecific variation in cold tolerance increases our understanding of the role of climatic gradients on the physiology of an invasive species,and contributes to tools for predicting further expansion.
文摘An investigation method with sample plots was used to study insect communities in four different growth phases of natural Populus euphratica forests, which are juvenile, middle aged, over-mature and degraded forests, in Tarim, Xinjiang in July, 2005 and April, 2006. In our studies, 5,116 insect specimens, belonging to 12 orders, 61 families and 141 species, were collected. Lepidoptera and Coleoptera were the dominant orders. In middle-aged forests, species, individual numbers and diversity indices of insect com-munities were higher than those in other woodlands. The species richness and diversity indices were lowest in degraded forests be-cause of extremely scarce vegetation.
文摘Eleven species of alien invasive forest insect pests have been found since the early time that insect species had been taken recorded in China. Their origins, inland distribution, invasive time, hosts, causing damage are recorded in this paper for the evidence of biological invasion. Their control methods are also studied or discussed.
基金funded by the Richard Ivey Foundationthe Haliburton ForestWild Life Reserve
文摘Insects respond to changes in microhabitat caused by canopy disturbance, and thus can be used to examine the ecological impacts of harvesting. Single-tree selection harvesting is the most common silvicultural system used to emulate local small-scale natural disturbance and maintain uneven-aged forest structure in temperate forests. Here, we test for differences in richness, abundance, and composition of hymenopteran and saproxylic insect assemblages at four different taxon levels （selected insect orders; and all hymenopteran families, and braconid subfamilies and morphospecies） between the canopy and understory of unharvested and single-tree selection harvested sites in a northern temperate forest from central Canada. Harvesting had no effect on insect assemblage richness, composition or abundance at the three highest taxon levels （order, family and subfamily）. Similarly, richness and abundance at the lowest-taxon level （braconid morphospecies） were similar, although composition differed slightly between unharvested and harvested stands. Insect assemblages were vertically stratified, with generally higher abundance （for Diptera, Hymenoptera, some hymenopteran families and braconid subfamilies） and richness （for braconid morphospecies） in the understory than the canopy. In particular, composition of the braconid morphospecies assemblage showed relatively low similarity between the understory and canopy. Single-tree selection harvesting appears to influence wood-associated insect taxa only subtly through small changes in community composition at the lowest taxon level, and thus is recommended as a conservative approach for managing these northern temperate forests.
基金supported by the Ontario Ministry of Natural Resources and Forestry(OMNRF)funded through the Sustainable Forest Management Network and the Faculty of Forestry,University of Toronto
文摘Saproxylic insect assemblages are essential functional components of forest ecosystems that can be affected by forest management.We used a split-plot ANOVA design to analyze differences in selected saproxylic insects（all arthropod orders and dipteran and parasitic hymenopteran families） emerging from dead wood of sites with different logging histories（horse-logged,mechanically-logged and unlogged）,tree species（Populus and Picea）,stage of decay（early-and late-decay stages） and posture（standing and downed logs） in the boreal forest of central Canada.No clear effects of logging history were seen for the studied taxa; however,interaction between logging history and other dead wood features was apparent.Cecidomyiidae consistently emerged more from Populus than from Picea dead wood.Most of the studied saproxylic families were more abundant in late-decay than in early-decay wood.Dipterans of the Cecidomyiidae,Ceratopogonidae,Empididae,Mycetophilidae and Sciaridae families,and hymenopterans of the Diapriidae and Ichneumonidae families were significantly more abundant in downed than in standing dead wood.In contrast,Mymaridae was most abundant in standing dead wood.Our study provides evidence that some insects at high taxonomic levels respond differently to dead wood quality,and this could inform future management strategies in the boreal forest for the conservation of saproxylic fauna and their ecological functions.
文摘Using tree-ring analysis, we show that the dynamics of forest tent caterpillar [Malacosoma disstria (Hbn.)] outbreaks in Alberta, Canada shifted at the turn of the 20th century from cyclic, synchronous behaviour 1850-1910 to complex, asynchronous behavior 1910-1993. This shift in dynamics coincided with the emergence in 1910 of a latitudinal gradient in outbreak stability and periodicity reflecting a similar gradient in the periodicity of winter temperatures. We postulate that the synchronizing strength of winter temperatures has diminished as a result of climate warming, and that any synchronizing strength due to inter-population migration has been superseded by regionalized patterns of periodic forcing caused by weak low-frequency variability in winter temperatures. We speculate that a decrease in polar vorticity at the start of the 20th century led to increased meridional jet stream flow and more frequent arctic weather anomalies, resulting in a loss of synchronous decadal periodicity in outbreak occurrence. These changes in insect disturbance probabilities, including rising uncertainty, have profound consequences for forest disturbance risk management.
文摘Assessing carbon (C) sequestration in forest ecosystems is fundamental to supply information to monitoring, reporting and verification (MRV) for reducing deforestation and forest degradation (REDD). The spatially-explicit version of Forest-DNDC (FDNDC) was evaluated using plot-based observations from Nez Perce-Clearwater National Forest (NPCNF) in Idaho of United States and used to assess C stocks in?about 16,000 km2. The model evaluation indicated that the FDNDC can be used to assess C stocks with disturbances in this temperate forest with a proper model performance efficiency and small error between observations and simulations. Aboveground biomass in this forest was 85.1 Mg C ha-1 in 2010. The mean aboveground biomass in the forest increased by about 0.6 Mg C ha-1 yr-1 in the last 20 years from 1990 to 2010 with spatial mean stand age about 98 years old in 2010. Spatial differences in distributions of biomass, net primary production and net ecosystem product are substantial. The spatial divergence in C sequestration is mainly associated with the spatial disparities in stand age due to disturbances, secondly with ecological drivers and species. Climate variability and change can substantially impact C stocks in the forest based on the climatic variability of spatial climate data for a 33-year period from 1981 to 2013. Temperature rise can produce more biomass in NPCNF, but biomass cannot increase with an increase in precipitation in this forest. The simulation with disturbances using observations and estimates for the time period from 1991 to 2011?showed the effects of disturbances on C stocks in forests. The impacts of fires and insects on C stocks in this forest are highly dependent on the severity, the higher, the more C loss to atmosphere due to?fires, and the more dead woods produced by fires and insects. The rates of biomass increase with an increase in stand age are different among the species. The changes in forest C stocks?in the forest are almost species specific, non-linear and complex. The increase in aboveground biomass with an increase in stand age can be described by a high-order polynomial.
