Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the envir...Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the environmental factors that are responsible for the variations in species composition and richness of alpine shrublands using numerical methods. In the present study, we investigated vegetation and associated environmental variables from 45 sample plots in the middle Qilian Mountains of the northwestern China to classify different community types and to elucidate the species- environment relationships. We also estimated the relative contributions of topography and site conditions to spatial distribution patterns of the shrub communities using the variation partitioning. The results showed that four shrub community types were identified and striking differences in fioristic composition were found among them. Species composition greatly depended on elevation, slope, shrub cover, soil pH and organic carbon. The important determinants of species richness were soil bulk density and slope. No significant differences in species richness were detected among the community types. Topography and site conditions had almost equal effects on compositional variation. Nonetheless,a large amount of the variation in species composition remained unexplained.展开更多
Understanding the environmental factors that influence tree species composition is essential for successful management of biodiversity and sustainable use of community forest resources.This study aims to assess tree s...Understanding the environmental factors that influence tree species composition is essential for successful management of biodiversity and sustainable use of community forest resources.This study aims to assess tree species composition and distribution in the deciduous Ban Mae Chiang Rai Lum Community Forest in Northern Thailand and to analyze the influence of environmental factors on tree biodiversity in the forest.We conducted a stratified systematic sampling of the forest’s total area of 3925 ha,and twenty-five 0.16 ha survey plots were established in three different stands of the deciduous forests to estimate and characterize the difference in biological diversity among the stands.Canonical correspondence analysis(CCA)was used to investigate the environment factors affecting such differences in biodiversity of the stands.The results showed a high diversity of trees in the forest as 197 species,144 genera,and 62 plant families were recorded.The CCA ordination identified the environmental factors—the most important of which were elevation,distance to streams,soil moisture,organic matter,and distance to communities—that signifi-cantly influenced the diversity and distribution of tree species(p<0.05)in the community forest.Our findings indicate that the implementation of drought reduction measures such as building check dams,fire protection,and monitoring community forest-product usage would be recommended to further biodiversity conservation and the sustainable use of community forest resources.展开更多
Vegetation and soil surveys were conducted under different site conditions in 2007-2011 to study species diversity using richness, evenness and diversity indices, in the middle portion of the Heihe River Basin. The re...Vegetation and soil surveys were conducted under different site conditions in 2007-2011 to study species diversity using richness, evenness and diversity indices, in the middle portion of the Heihe River Basin. The relationship between species distribution and soil environmental factors was also studied by Canonical Correspondence Analysis （CCA）. Results show that vegetation coverage and species diversity were the highest in the interdune lowland, and the lowest in the mobile dime. Results of the Hill＇s index （di- versity ordering） shows that species diversity is reduced along decreasing soil water content, and the order of species diversity was interdune lowland, flat slope, fixed dune, semifixed dune and mobile dune. The influence degree of soil factors on vegetation dis- tribution was soil water content 〉 pH 〉 total K 〉 organic matter 〉 available N 〉 total N 〉 available K 〉 total P 〉 saline content 〉 available P. Soil water content and pH were important factors significantly affecting spatial distribution difference of vegetation, the environmental explanation was 98%.展开更多
Types and structure of plant communities in the Yellow River Delta were investigated by using detrended canonical correspondence analyses （DCCAs） and a two-way indicator species analysis （TWINSPAN）. The distributi...Types and structure of plant communities in the Yellow River Delta were investigated by using detrended canonical correspondence analyses （DCCAs） and a two-way indicator species analysis （TWINSPAN）. The distribution pattern and influential factors of the plant communities were also analyzed by testing elevation, slope, soil characteristics, longitude and latitude of 134 vegetation samples collected by representative plot sampling methods. Results showed that all the 134 vegetation samples could be divided into seven vegetation groups, separately dominated by Robinia pseucdoacacia, Imperata cylindrical, Miscanthus saccharifleus, Suaeda salsa, Aeluropus sinensis, Phragmites australis and Tamarix chinensis. The vegetation distribution pattern was mainly related to elevation, ground water depth and soil characteristics such as salinity and soluble potassium. Among the factors affecting distribution pattern of the plant communities, the species matrix explained by non-spatial environmental variation accounts for 45.2% of total variation. Spatial variation and spatial-structured environmental variation explain 11.8%, and 2.2%, respectively. Remained 40.8% of undetermined variation is attributed to biological and stochastic factors.展开更多
The relationships between invasive plant species and environmental and anthropogenic factors were analyzed in five nature reserves in northern China. The distribution of invasive plants was analyzed using a Canonical ...The relationships between invasive plant species and environmental and anthropogenic factors were analyzed in five nature reserves in northern China. The distribution of invasive plants was analyzed using a Canonical Correspondence Analysis. Stepwise backward multiple regression was then done to identify the most important environmental and anthropogenic factors determining the richness and distribution of alien plants in the reserves. Total invasive plant richness varied was 25 species, 12 species, 13 species, five species and five species across the nature reserves. Invasive species richness decreased in response to environmental factors such as maximum temperature and minimum precipitation and increased in line with human activities, the total area of farmland and volume of freight. Tropical plant species declined from 31% to zero while the species originally from North America gradually increased. In respect of family composition of invasive species, most species belonged to the composites, whose proportion increased from 15%-40% from north to south across the five nature reserves while species from other families varied greatly along this gradient. Life-forms of invasive plant species varied between the reserves, but annual and perennial herbs were generally dominant. Pathways of such species were highly related to human activities and utilizations.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 91025002)
文摘Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the environmental factors that are responsible for the variations in species composition and richness of alpine shrublands using numerical methods. In the present study, we investigated vegetation and associated environmental variables from 45 sample plots in the middle Qilian Mountains of the northwestern China to classify different community types and to elucidate the species- environment relationships. We also estimated the relative contributions of topography and site conditions to spatial distribution patterns of the shrub communities using the variation partitioning. The results showed that four shrub community types were identified and striking differences in fioristic composition were found among them. Species composition greatly depended on elevation, slope, shrub cover, soil pH and organic carbon. The important determinants of species richness were soil bulk density and slope. No significant differences in species richness were detected among the community types. Topography and site conditions had almost equal effects on compositional variation. Nonetheless,a large amount of the variation in species composition remained unexplained.
基金supported by the Southeast Asian Regional Center for Graduate Study and Research in Agriculture(SEARCA)-ASEAN Working Group on Social Forestry Strategic Response Fund(ASRF)under the ASEANSwiss Partnership on Social Forestry and Climate Change and by the R&D Program for Forest Science Technology(Project No.2018113C10-2020-BB01)provided by Korea Forest Service(Korea Forestry Promotion Institute).
文摘Understanding the environmental factors that influence tree species composition is essential for successful management of biodiversity and sustainable use of community forest resources.This study aims to assess tree species composition and distribution in the deciduous Ban Mae Chiang Rai Lum Community Forest in Northern Thailand and to analyze the influence of environmental factors on tree biodiversity in the forest.We conducted a stratified systematic sampling of the forest’s total area of 3925 ha,and twenty-five 0.16 ha survey plots were established in three different stands of the deciduous forests to estimate and characterize the difference in biological diversity among the stands.Canonical correspondence analysis(CCA)was used to investigate the environment factors affecting such differences in biodiversity of the stands.The results showed a high diversity of trees in the forest as 197 species,144 genera,and 62 plant families were recorded.The CCA ordination identified the environmental factors—the most important of which were elevation,distance to streams,soil moisture,organic matter,and distance to communities—that signifi-cantly influenced the diversity and distribution of tree species(p<0.05)in the community forest.Our findings indicate that the implementation of drought reduction measures such as building check dams,fire protection,and monitoring community forest-product usage would be recommended to further biodiversity conservation and the sustainable use of community forest resources.
基金financially supported by the National Natural Sciences Foundation of China (91025026 and 31070359)
文摘Vegetation and soil surveys were conducted under different site conditions in 2007-2011 to study species diversity using richness, evenness and diversity indices, in the middle portion of the Heihe River Basin. The relationship between species distribution and soil environmental factors was also studied by Canonical Correspondence Analysis （CCA）. Results show that vegetation coverage and species diversity were the highest in the interdune lowland, and the lowest in the mobile dime. Results of the Hill＇s index （di- versity ordering） shows that species diversity is reduced along decreasing soil water content, and the order of species diversity was interdune lowland, flat slope, fixed dune, semifixed dune and mobile dune. The influence degree of soil factors on vegetation dis- tribution was soil water content 〉 pH 〉 total K 〉 organic matter 〉 available N 〉 total N 〉 available K 〉 total P 〉 saline content 〉 available P. Soil water content and pH were important factors significantly affecting spatial distribution difference of vegetation, the environmental explanation was 98%.
基金Foundation project： This study was financially supported by the Na- tional Natural Science Foundation of China （No. 40771172） and the orientation project of the Chinese Academy of Sciences （No. kzcx2-yw-308）
文摘Types and structure of plant communities in the Yellow River Delta were investigated by using detrended canonical correspondence analyses （DCCAs） and a two-way indicator species analysis （TWINSPAN）. The distribution pattern and influential factors of the plant communities were also analyzed by testing elevation, slope, soil characteristics, longitude and latitude of 134 vegetation samples collected by representative plot sampling methods. Results showed that all the 134 vegetation samples could be divided into seven vegetation groups, separately dominated by Robinia pseucdoacacia, Imperata cylindrical, Miscanthus saccharifleus, Suaeda salsa, Aeluropus sinensis, Phragmites australis and Tamarix chinensis. The vegetation distribution pattern was mainly related to elevation, ground water depth and soil characteristics such as salinity and soluble potassium. Among the factors affecting distribution pattern of the plant communities, the species matrix explained by non-spatial environmental variation accounts for 45.2% of total variation. Spatial variation and spatial-structured environmental variation explain 11.8%, and 2.2%, respectively. Remained 40.8% of undetermined variation is attributed to biological and stochastic factors.
基金the China Bureau of Foreign Experts, the Ministry of Education of China (111 Program, Grant 2008-B08044)"985 Programme" of Minzu University of China (Grant Number MUC98504-14, MUC98507-08)
文摘The relationships between invasive plant species and environmental and anthropogenic factors were analyzed in five nature reserves in northern China. The distribution of invasive plants was analyzed using a Canonical Correspondence Analysis. Stepwise backward multiple regression was then done to identify the most important environmental and anthropogenic factors determining the richness and distribution of alien plants in the reserves. Total invasive plant richness varied was 25 species, 12 species, 13 species, five species and five species across the nature reserves. Invasive species richness decreased in response to environmental factors such as maximum temperature and minimum precipitation and increased in line with human activities, the total area of farmland and volume of freight. Tropical plant species declined from 31% to zero while the species originally from North America gradually increased. In respect of family composition of invasive species, most species belonged to the composites, whose proportion increased from 15%-40% from north to south across the five nature reserves while species from other families varied greatly along this gradient. Life-forms of invasive plant species varied between the reserves, but annual and perennial herbs were generally dominant. Pathways of such species were highly related to human activities and utilizations.
