Red turpentine beetle （RTB）, Dendroctongs valens LeConte, is a destructive forest invasive species in China, it mainly attacks Pings tabuliformis and P. bungeana. So far it has spread rapidly to the provinces of Sha...Red turpentine beetle （RTB）, Dendroctongs valens LeConte, is a destructive forest invasive species in China, it mainly attacks Pings tabuliformis and P. bungeana. So far it has spread rapidly to the provinces of Shanxi, Hebei, Henan, Shanxi and Beijing since its first outbreak in Shanxi Province in 1998, and has caused extensive tree mortality. Space-time dynamics of D. valens population and spatial sampling technique based on its spatial distribution pattern were ana- lyzed using geostatistical methods in the pure P. tabuliforis forests and mixedwood stands which were at different damage levels. According to the spatial distribu- tion of D. valeas population, the specific spatial sampling technique was also studied, and then was compared with traditional sampling technique. The spatial sam- piing technique combined with sampling theory and the biological characteristics of D. valens population, which not only could calcnlate the error of the sampling, but also could discuss the optimal sampling number and the optimum size of plot according to different damage levels and different stand types. This helps to explain population expansion and colonization mechanism of D. valens, and to provide a good reference for adopting snitable control measures.展开更多
Carabid beetles,predatory insects,are abundant in forests and sensitive to environmental changes.The distribution patterns and diversity of carabid beetles in several natural forests were studied to provide a basis fo...Carabid beetles,predatory insects,are abundant in forests and sensitive to environmental changes.The distribution patterns and diversity of carabid beetles in several natural forests were studied to provide a basis for evaluating the importance of a forest in the protection of carabid beetle diversity.Carabids were captured by pitfall traps during their seasonal activity from 2012 to 2013 in a poplar-birch forest,ash-walnut forest and broad-leaved Korean pine forest.A total of 5252 individuals,representing 21 species,were collected.Carabid abundance was highest in the broad-leaved Korean pine forest and lowest in the ash-walnut forest.Carabus billbergi Mannerheim and Pterostichus pertinax(Tschitscherine)were the dominant beetle species in each stand.Carabus canaliculatus Adams was dominant in the poplar-birch and ash-walnut forests,and Leistus niger Gebler was dominant in the ash-walnut forest.The carabids were affected differently by stand factors.C.billbergi and P.pertinax was positively correlated with mean DBH.C.canaliculatus and L.niger were not positively correlated with any stand factors.The broad-leaved Korean pine forest with greater age,large DBH and thick leaf litter fostered a high diversity of carabid species.The main yearly activity period for most carabids was during July.Different carabid species responded differently to seasonality,and the activity period of several species was relatively late(August)in the year.展开更多
The investigation was conducted on the spatial and temporal distributions of soil organic mater （SOM） in the mixed plantations of alder （Aluns crernastogyne） and cypress （Cupressus funebris ） （MPAC）, which dis...The investigation was conducted on the spatial and temporal distributions of soil organic mater （SOM） in the mixed plantations of alder （Aluns crernastogyne） and cypress （Cupressus funebris ） （MPAC）, which distributed in the hilly areas of central Sichuan Basin （HACSB）. The results show that： （1） the spatial distribution of SOM among different sites at the same age are not significant before 15-year-old, but significant at 20-year-old, and not significant again after 25-year-old; （2） the SOM contents in 0-15 cm and 15-30 cm layers increase sharply from 10- to 15-year-old, and decline gradually from 15- to 30- year-old; the SOM contents of the 30-year-old PCP were 80. 38% and 78.42% higher than that of the 10-year-old, but 29.16% and 53.37% lower than that of 15-year-old in the 0-15 cm and 15-30 cm layers, respectively. The decrease of SOM contents would lead to the degradation of soil fertility and the decline of forest productivity.展开更多
Here,we quantitatively determine temporal and spatial distribution characteristics of main grain crops in the West Liaohe River basin,Inner Mongolia,China,from 2000 to 2010 based on MODIS remote sensing data and NDVI ...Here,we quantitatively determine temporal and spatial distribution characteristics of main grain crops in the West Liaohe River basin,Inner Mongolia,China,from 2000 to 2010 based on MODIS remote sensing data and NDVI time series information for the years 2000,2005 and 2010.Phenological calendars and a decisionmaking tree extraction model were also used to obtain spatial distribution information of spring maize,spring wheat and soybean.We found that in 2010,the sown area of the main grain crops in the West Liaohe River basin was 11 965.08km2,of which,the sown area for spring maize accounted for 92.28%and was concentrated in the lower reaches of the region.Spring wheat accounted for 3.14% and was mainly in the middle reaches.Soybean accounted for 4.58% and was predominantly in the upper reaches.From 2000 to 2005,the sown area of these grain crops in the West Liaohe River basin grew by 29.77%,mainly in the lower reaches： spring maize grew by 38.99%,spring wheat by 39.04% and soybean by 21.27%.From 2005 to 2010,growth in the sown area of these crops was slow（5.18% growth） and mainly in the lower reaches of the basin.The sown area of spring maize increased,but decreased for both spring wheat and soybean.展开更多
[Objective] Study on the spatial distribution of summer precipitation patterns and interannual and interdecadal variability. [Method] The summer precipitation patterns were obtained from standard field of summer preci...[Objective] Study on the spatial distribution of summer precipitation patterns and interannual and interdecadal variability. [Method] The summer precipitation patterns were obtained from standard field of summer precipitation data for 160 observation stations in China during 1951 -2000 by the utilization of empirical orthogonal function （EOF）, and characteristics of interannual and interdecadal variability were analyzed. [Result] The summer precipitation mainly distributes in eastern part of China; The 1 st, 2nd and 3rd EOF modes of spatial distribution are especially remarkable as well consistent with the results of previous reports about three rainfall patterns from analysis on the percentages of precipitation anomaly of summer. [Conclusion] There exists interannual and interdecadal variability for summer precipitation in China.展开更多
基金Supported by Research Project of Jiangsu Entry-Exit Inspection and Quarantine Bureau(2015KJ49)Project of Beijing Municipal Education Commission(JD100220888)+2 种基金Project of Beijing Excellent Talents Funding(D Class)Project of Beijing Municipal Education Commission(JD100220888)Beijing Excellent Talents Funding(D Class)Project "Study on Prevention and Control Technology of Dendroctonus valens"
文摘Red turpentine beetle （RTB）, Dendroctongs valens LeConte, is a destructive forest invasive species in China, it mainly attacks Pings tabuliformis and P. bungeana. So far it has spread rapidly to the provinces of Shanxi, Hebei, Henan, Shanxi and Beijing since its first outbreak in Shanxi Province in 1998, and has caused extensive tree mortality. Space-time dynamics of D. valens population and spatial sampling technique based on its spatial distribution pattern were ana- lyzed using geostatistical methods in the pure P. tabuliforis forests and mixedwood stands which were at different damage levels. According to the spatial distribu- tion of D. valeas population, the specific spatial sampling technique was also studied, and then was compared with traditional sampling technique. The spatial sam- piing technique combined with sampling theory and the biological characteristics of D. valens population, which not only could calcnlate the error of the sampling, but also could discuss the optimal sampling number and the optimum size of plot according to different damage levels and different stand types. This helps to explain population expansion and colonization mechanism of D. valens, and to provide a good reference for adopting snitable control measures.
基金supported by grants from the National Natural Science Foundation of China(31600517)the Science and Technology Development Project of Jilin Province(20180201059NY)+2 种基金Science and Technology Research Project of Jilin Provincial Education Department(JJKH20190651KJ)Open Project of Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains,Ministry of Education(GPES202003)National College Students’Innovation and Entrepreneurship Training Program(202110201030)。
文摘Carabid beetles,predatory insects,are abundant in forests and sensitive to environmental changes.The distribution patterns and diversity of carabid beetles in several natural forests were studied to provide a basis for evaluating the importance of a forest in the protection of carabid beetle diversity.Carabids were captured by pitfall traps during their seasonal activity from 2012 to 2013 in a poplar-birch forest,ash-walnut forest and broad-leaved Korean pine forest.A total of 5252 individuals,representing 21 species,were collected.Carabid abundance was highest in the broad-leaved Korean pine forest and lowest in the ash-walnut forest.Carabus billbergi Mannerheim and Pterostichus pertinax(Tschitscherine)were the dominant beetle species in each stand.Carabus canaliculatus Adams was dominant in the poplar-birch and ash-walnut forests,and Leistus niger Gebler was dominant in the ash-walnut forest.The carabids were affected differently by stand factors.C.billbergi and P.pertinax was positively correlated with mean DBH.C.canaliculatus and L.niger were not positively correlated with any stand factors.The broad-leaved Korean pine forest with greater age,large DBH and thick leaf litter fostered a high diversity of carabid species.The main yearly activity period for most carabids was during July.Different carabid species responded differently to seasonality,and the activity period of several species was relatively late(August)in the year.
文摘The investigation was conducted on the spatial and temporal distributions of soil organic mater （SOM） in the mixed plantations of alder （Aluns crernastogyne） and cypress （Cupressus funebris ） （MPAC）, which distributed in the hilly areas of central Sichuan Basin （HACSB）. The results show that： （1） the spatial distribution of SOM among different sites at the same age are not significant before 15-year-old, but significant at 20-year-old, and not significant again after 25-year-old; （2） the SOM contents in 0-15 cm and 15-30 cm layers increase sharply from 10- to 15-year-old, and decline gradually from 15- to 30- year-old; the SOM contents of the 30-year-old PCP were 80. 38% and 78.42% higher than that of the 10-year-old, but 29.16% and 53.37% lower than that of 15-year-old in the 0-15 cm and 15-30 cm layers, respectively. The decrease of SOM contents would lead to the degradation of soil fertility and the decline of forest productivity.
基金National Natural Science Foundation of China(41271541)
文摘Here,we quantitatively determine temporal and spatial distribution characteristics of main grain crops in the West Liaohe River basin,Inner Mongolia,China,from 2000 to 2010 based on MODIS remote sensing data and NDVI time series information for the years 2000,2005 and 2010.Phenological calendars and a decisionmaking tree extraction model were also used to obtain spatial distribution information of spring maize,spring wheat and soybean.We found that in 2010,the sown area of the main grain crops in the West Liaohe River basin was 11 965.08km2,of which,the sown area for spring maize accounted for 92.28%and was concentrated in the lower reaches of the region.Spring wheat accounted for 3.14% and was mainly in the middle reaches.Soybean accounted for 4.58% and was predominantly in the upper reaches.From 2000 to 2005,the sown area of these grain crops in the West Liaohe River basin grew by 29.77%,mainly in the lower reaches： spring maize grew by 38.99%,spring wheat by 39.04% and soybean by 21.27%.From 2005 to 2010,growth in the sown area of these crops was slow（5.18% growth） and mainly in the lower reaches of the basin.The sown area of spring maize increased,but decreased for both spring wheat and soybean.
文摘[Objective] Study on the spatial distribution of summer precipitation patterns and interannual and interdecadal variability. [Method] The summer precipitation patterns were obtained from standard field of summer precipitation data for 160 observation stations in China during 1951 -2000 by the utilization of empirical orthogonal function （EOF）, and characteristics of interannual and interdecadal variability were analyzed. [Result] The summer precipitation mainly distributes in eastern part of China; The 1 st, 2nd and 3rd EOF modes of spatial distribution are especially remarkable as well consistent with the results of previous reports about three rainfall patterns from analysis on the percentages of precipitation anomaly of summer. [Conclusion] There exists interannual and interdecadal variability for summer precipitation in China.
