Analyzing and measuring the spatial distribution pattern of human settlement environment suitability in Beichuan County China is of great significance for optimizing population distribution and promoting human develop...Analyzing and measuring the spatial distribution pattern of human settlement environment suitability in Beichuan County China is of great significance for optimizing population distribution and promoting human development and environmental protection. Based on the DEM data and other data of Beichuan County, this paper uses GIS and ENVI software to extract four spatial distribution data of vegetation coverage index, topographic relief, hydrological index and natural disaster risk, and the spatial distribution pattern of natural suitability of human settlement environment in Beichuan County was obtained through overlay analysis. The results show: 1) Most of the areas with small topographic relief are located in the southeast of the study area, which is New Beichuan County and Anchang Town and Yong’an Town. The vegetation coverage index in the eastern region is higher, while the vegetation coverage index in the western and other high altitude regions is lower because there are more grasslands. 2) From the perspective of spatial distribution, Beichuan County as a whole is rich in water resources in the central and eastern part of the county, while the west is short of water resources;Chenjiaba Township, Guixi Town and Old Beichuan County are located on the fault zone with high natural disaster risk, the natural disaster risk is high in Piankou Township and Xiaoba Town and Kaiping Township Area. 3) The human settlement environment index of Beichuan county is 19.72 - 85.25;The natural suitability is the highest in the southeast, followed by the central and western regions, and the worst is located in the Piankou-Xiaoba and Old Beichuan-Guixi fault zones. 4) The general suitable area in Beichuan County is the largest, accounting for 30.4% of the total area of the study area. More suitable area ranked second, accounting for 29.33%;critical fitness suitable area accounted for 17.87%;the area of suitable highly suitable area accounted for 14.06%, and the unsuitable area accounted for 8.32%. Reasonable and efficient development and use of local resources is an inevitable way for the sustainable development of Beichuan County.展开更多
Leaf functional traits are adaptations that enable plants to live under various environmental conditions. This study aims to determine the differences in leaf functional traits among plants grouped by growth habit, le...Leaf functional traits are adaptations that enable plants to live under various environmental conditions. This study aims to determine the differences in leaf functional traits among plants grouped by growth habit, leaf life span,leaf lifestyle, leaf form, and origin. Specific leaf area（SLA） of perennial or evergreen species was lower than that of annual or deciduous species because longer-lived leaves of perennial or evergreen species require more investment in structural integrity and/or defense against disturbances, especially with any resource constraint. SLA of large individuals was lower than that of small individuals. The low SLA in large individuals can improve their response to changing light and water conditions because increasing plant height is advantageous for light competition, but it can also impose a cost in terms of structural support and water transport. Petioles of plants with compound leaves were significantly longer than those of simple leaves because branching is expensive in terms of gaining height. SLA of plants increased with increasing invasiveness accordingly, and SLA of invasive plants was higher than that of their native congeners because invasive plants should invest more biomass on leaf growth rather than leaf structures per unit area to achieve a higher growth rate.Overall, variation in leaf functional traits among different groups may play an adaptive role in the successful survival of plants under diverse environments because leaf functional traits can lead to pronounced effects on leaf function,especially the acquisition and use of light. Plant species with different growth and leaf traits balance resource acquisition and leaf construction to minimize trade-offs and achieve fitness advantages in their natural habitat.展开更多
Aims Numerous studies have showed that the balance between negative and positive plant–plant interactions shifted along environmental gradients.But little is known how the positive or negative plant–plant interactio...Aims Numerous studies have showed that the balance between negative and positive plant–plant interactions shifted along environmental gradients.But little is known how the positive or negative plant–plant interactions varied with temporal fluctuating habitat conditions and plant ontogenetic phases.Methods In a 2-year experiment,the four perennial grasses(Kobresia humilis,Stipa aliena,Elymus nutans and Saussurea superba)were grown under four interaction treatments(no root or shoot interaction,only shoot interaction,only root interaction,root and shoot interaction).Intensity of above-and belowground interactions is proposed to vary with the fluctuation of seasonal climatic conditions and soil available nutrients.Here we report measurements of above-and belowground interactions during entire growing season.Correlation between plant interaction intensity and seasonal soil available N as well as habitat climate conditions was also performed.Important findings Our experiment found that root interactions had negative effect on plant growth for the four species during growing season.However,both negative and positive shoot interactions occurred among the four species.Despite there being shoot facilitative effect for E.nutans and S.superba,the full interaction was negative,suggested that root interaction take more important role on plant growth than that of shoot interaction.The interaction between root and shoot effect varied as a function of species identity and growth phases.The weak correlation of plant interaction intensity to habitat environmental factors suggested that plant ontogenetic characteristics may be primary factors causing temporal variation in plant interaction.展开更多
文摘Analyzing and measuring the spatial distribution pattern of human settlement environment suitability in Beichuan County China is of great significance for optimizing population distribution and promoting human development and environmental protection. Based on the DEM data and other data of Beichuan County, this paper uses GIS and ENVI software to extract four spatial distribution data of vegetation coverage index, topographic relief, hydrological index and natural disaster risk, and the spatial distribution pattern of natural suitability of human settlement environment in Beichuan County was obtained through overlay analysis. The results show: 1) Most of the areas with small topographic relief are located in the southeast of the study area, which is New Beichuan County and Anchang Town and Yong’an Town. The vegetation coverage index in the eastern region is higher, while the vegetation coverage index in the western and other high altitude regions is lower because there are more grasslands. 2) From the perspective of spatial distribution, Beichuan County as a whole is rich in water resources in the central and eastern part of the county, while the west is short of water resources;Chenjiaba Township, Guixi Town and Old Beichuan County are located on the fault zone with high natural disaster risk, the natural disaster risk is high in Piankou Township and Xiaoba Town and Kaiping Township Area. 3) The human settlement environment index of Beichuan county is 19.72 - 85.25;The natural suitability is the highest in the southeast, followed by the central and western regions, and the worst is located in the Piankou-Xiaoba and Old Beichuan-Guixi fault zones. 4) The general suitable area in Beichuan County is the largest, accounting for 30.4% of the total area of the study area. More suitable area ranked second, accounting for 29.33%;critical fitness suitable area accounted for 17.87%;the area of suitable highly suitable area accounted for 14.06%, and the unsuitable area accounted for 8.32%. Reasonable and efficient development and use of local resources is an inevitable way for the sustainable development of Beichuan County.
基金supported by the National Natural Science Foundation of China(31300343)Natural Science Foundation of Jiangsu Province,China(BK20130500)Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment,Research Foundation for Advanced Talents,Jiangsu University(12JDG086)
文摘Leaf functional traits are adaptations that enable plants to live under various environmental conditions. This study aims to determine the differences in leaf functional traits among plants grouped by growth habit, leaf life span,leaf lifestyle, leaf form, and origin. Specific leaf area（SLA） of perennial or evergreen species was lower than that of annual or deciduous species because longer-lived leaves of perennial or evergreen species require more investment in structural integrity and/or defense against disturbances, especially with any resource constraint. SLA of large individuals was lower than that of small individuals. The low SLA in large individuals can improve their response to changing light and water conditions because increasing plant height is advantageous for light competition, but it can also impose a cost in terms of structural support and water transport. Petioles of plants with compound leaves were significantly longer than those of simple leaves because branching is expensive in terms of gaining height. SLA of plants increased with increasing invasiveness accordingly, and SLA of invasive plants was higher than that of their native congeners because invasive plants should invest more biomass on leaf growth rather than leaf structures per unit area to achieve a higher growth rate.Overall, variation in leaf functional traits among different groups may play an adaptive role in the successful survival of plants under diverse environments because leaf functional traits can lead to pronounced effects on leaf function,especially the acquisition and use of light. Plant species with different growth and leaf traits balance resource acquisition and leaf construction to minimize trade-offs and achieve fitness advantages in their natural habitat.
基金National Natural Science Foundation of China(grant no.30600070)the National Basic Research program of China(grant no.2005CB422005).
文摘Aims Numerous studies have showed that the balance between negative and positive plant–plant interactions shifted along environmental gradients.But little is known how the positive or negative plant–plant interactions varied with temporal fluctuating habitat conditions and plant ontogenetic phases.Methods In a 2-year experiment,the four perennial grasses(Kobresia humilis,Stipa aliena,Elymus nutans and Saussurea superba)were grown under four interaction treatments(no root or shoot interaction,only shoot interaction,only root interaction,root and shoot interaction).Intensity of above-and belowground interactions is proposed to vary with the fluctuation of seasonal climatic conditions and soil available nutrients.Here we report measurements of above-and belowground interactions during entire growing season.Correlation between plant interaction intensity and seasonal soil available N as well as habitat climate conditions was also performed.Important findings Our experiment found that root interactions had negative effect on plant growth for the four species during growing season.However,both negative and positive shoot interactions occurred among the four species.Despite there being shoot facilitative effect for E.nutans and S.superba,the full interaction was negative,suggested that root interaction take more important role on plant growth than that of shoot interaction.The interaction between root and shoot effect varied as a function of species identity and growth phases.The weak correlation of plant interaction intensity to habitat environmental factors suggested that plant ontogenetic characteristics may be primary factors causing temporal variation in plant interaction.
