定量评价人类出行活动强度(下文简称“人类出行强度”)是进行人类干扰研究的基础,对于生物多样性保护具有重要意义。考虑到城市与非城市区域之间的差异,为了提高人类出行强度对环境变量的响应程度,本文针对云南省非城市区域,基于腾讯位...定量评价人类出行活动强度(下文简称“人类出行强度”)是进行人类干扰研究的基础,对于生物多样性保护具有重要意义。考虑到城市与非城市区域之间的差异,为了提高人类出行强度对环境变量的响应程度,本文针对云南省非城市区域,基于腾讯位置大数据,利用地理探测器和最大熵模型探究环境变量对人类出行强度的影响。结果表明,影响云南省人类出行强度的各环境变量在交互作用下呈现双因子增强或非线性增强类型,距居民点距离与地表覆盖类型共同作用下对人类出行强度的解释力达到最大;最大熵模型的预测精度达到“好”的标准(Area Under Curve,AUC=0.855),研究区内的人类出行强度大致呈“东高、西低”的分布格局,距居民点距离、地表覆盖类型、距道路距离和坡度是主要的影响变量,累积贡献率超过90%;从整体上看,云南省内的人类出行活动集中于地势平缓、气候温暖、雨量适中且交通便利的居民区附近,实验结果对于揭示人类出行的分异性影响因素有价值,可为云南省的物种保护与规划等工作提供参考。展开更多
Based on data from 22 sample plots and applying the Canonical Correspondence Analysis (CCA),this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu Basi...Based on data from 22 sample plots and applying the Canonical Correspondence Analysis (CCA),this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu Basin,which is situated in the easternmost end of the Tianshan Mountains,Xinjiang Uygur Autonomous Region,China.For the zonal vegetation,community diversity of mountain vegetation is higher than that of the desert vegetation due to environmental factors.The CCA ordination diagram revealed that the composition and distribution of vegetation types are mainly determined by altitude,soil pH and soil salt content.With increasing elevation,the soil pH and total salt content decrease but the contents of soil organic matter,soil water,total nitrogen and total phosphorus increase gradually.In the CCA ordination diagrams,the sample plots and main species can be divided into five types according to their adaptations to the environmental factors.Type I is composed of desert vegetation distributed on the low mountains,hills,plains and deserts below an elevation of 1900 m;type II is distributed in the mountain and desert ecotone with an elevation of 1900-2300 m,and includes steppe desert,desert steppe and wetland meadow;type III is very simply composed of only salinized meadow;type IV is distributed above an elevation of 2300 m,containing mountain steppe,meadow steppe,subalpine meadow and alpine meadow;type V only contains salinized meadow.The results show that with increasing elevation,species combination changes from the xerophytic shrubs,semi-shrubs and herbs distributed in the low altitude zone with arid climate to the cold-tolerant perennial herbs growing in the high altitudinal zone with cold climate.展开更多
The Gurbantunggut Desert is the largest stable and semi-stable sand desert in China, yet few data exist on vegetation pattern and species-environment relationships for these diverse desert landscapes. The sand dunes o...The Gurbantunggut Desert is the largest stable and semi-stable sand desert in China, yet few data exist on vegetation pattern and species-environment relationships for these diverse desert landscapes. The sand dunes of the survey area are mainly of the longi- tudinal form from north to south, but checkerboard-shaped and honeycomb-shaped forms are also present, with the height of 10-50 m. We measured vegetation and soil data on north-south transects and compared them with vegetation and soil data on east-west transects. Analysis revealed that the varying trend and strength of the species diversity, dominance and cover of the plant communities in the longitudinal and transverse directions across the landscape are significantly different. The results of CCA ordination show that the microhabitats of soil organic matter （OM）, soil salts （TS）, sorting index （ σ ）, topsoil water-content （SM） and pH relate to the differences in vegetation observed as differences in species assemblage from salt-intolerant ephemerals, micro-subshrubs and subshrubs to salt-tolerant shrubs and micro-arbors. The terrain （alt.） and soil texture （the contents of Mz and Ф 1） affect the spatial differentiation of many species. However, this spatial differentiation is not so marked on transects running longitudinally with the landscape, in the same direction as the dunes. The species of the desert vegetation have formed three assemblages under the action of habitat gradients, relating to three sections running transversely across the landscape, at right angles to the direction of the dune crests. In the mid-east section of the study area the topography is higher, with sand-lands or dune-slopes with coarse particles. Here the dominant vegetation comprises shrubs and subshrubs of Seriphidium santofium and Ephedra distachya, with large numbers of ephemeral and ephemeroid plants of Senecio subdentatus, and Carex physodes in spring and summer. On the soil of the dune-slopes in the mid-west of the study area, with coarse particles and abundant TK, the plant assemblage of Haloxylon persicum, Soranthus meyeri and Agriophyllum squarrosum is developed. The species composition in the east marginal belt of the study area has similar characteristics to the mid-west section. There is no corresponding section in the north-south transects （except for the north and south margins）. This is because the habitats of most plants are located in the middle of the microhabitat gradients in the north-south direction in the desert.展开更多
In the present research,the authors measured parameters of richness,cover and importance value of ephemeral and ephemeroid plants on south-north and east-west transects in the Gurbantünggüt Desert in early s...In the present research,the authors measured parameters of richness,cover and importance value of ephemeral and ephemeroid plants on south-north and east-west transects in the Gurbantünggüt Desert in early spring,and investigated and analyzed the microhabitats,such as terrain,geomorphology,soil physical-chemical properties and crusts. By comparison,the regional differences in the ephemeral distribution in the desert were revealed. The species of ephemeral plants in the south and center are the richest and those in the west are the poorest in the desert. The cover of ephemeral plants in the mid-south is higher than that in the north,and that in the mid-east is higher than that in the west. The response of ephemeral plants to the spatial variation of the desert habitat forms the population-habitat gradient of ephemeral plants. The characteristics are:(1) In the habitat with higher terrain,coarser textured soil with poorer sorting and correspondingly higher organic matter and lower alkali-saline contents,Carex physoides and Eremopyrum orientale are the dominant ephemeral plants;(2) In the dry habitat with lower terrain,looser textured soil,some organic matter,alkali-saline soil,and developed crust,the ephemeral plants Alyssum linifolium and Erodium oxyrrhynchum are of characteristic of drought and alkali-saline tolerance;(3) In the habitat with lower terrain,some water and more alkali-saline soil,the ephemeral plants Neotorularia torulosa and Hypecoum parviflorum being of alkali-saline tolerance are mainly developed. However,most ephemerals are distributed in a habitat order of higher terrain,some organic,and less alkali-saline soil on the above-mentioned ephemeral population-habitat gradient. The spatial gradient of variation in desert microhabitats is small,and as a whole,the physio-logical character of mesophytism is represented by the desert ephemerals.展开更多
文摘定量评价人类出行活动强度(下文简称“人类出行强度”)是进行人类干扰研究的基础,对于生物多样性保护具有重要意义。考虑到城市与非城市区域之间的差异,为了提高人类出行强度对环境变量的响应程度,本文针对云南省非城市区域,基于腾讯位置大数据,利用地理探测器和最大熵模型探究环境变量对人类出行强度的影响。结果表明,影响云南省人类出行强度的各环境变量在交互作用下呈现双因子增强或非线性增强类型,距居民点距离与地表覆盖类型共同作用下对人类出行强度的解释力达到最大;最大熵模型的预测精度达到“好”的标准(Area Under Curve,AUC=0.855),研究区内的人类出行强度大致呈“东高、西低”的分布格局,距居民点距离、地表覆盖类型、距道路距离和坡度是主要的影响变量,累积贡献率超过90%;从整体上看,云南省内的人类出行活动集中于地势平缓、气候温暖、雨量适中且交通便利的居民区附近,实验结果对于揭示人类出行的分异性影响因素有价值,可为云南省的物种保护与规划等工作提供参考。
基金Under the auspices of National Natural Science Foundation of China(No.41171157)
文摘Based on data from 22 sample plots and applying the Canonical Correspondence Analysis (CCA),this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu Basin,which is situated in the easternmost end of the Tianshan Mountains,Xinjiang Uygur Autonomous Region,China.For the zonal vegetation,community diversity of mountain vegetation is higher than that of the desert vegetation due to environmental factors.The CCA ordination diagram revealed that the composition and distribution of vegetation types are mainly determined by altitude,soil pH and soil salt content.With increasing elevation,the soil pH and total salt content decrease but the contents of soil organic matter,soil water,total nitrogen and total phosphorus increase gradually.In the CCA ordination diagrams,the sample plots and main species can be divided into five types according to their adaptations to the environmental factors.Type I is composed of desert vegetation distributed on the low mountains,hills,plains and deserts below an elevation of 1900 m;type II is distributed in the mountain and desert ecotone with an elevation of 1900-2300 m,and includes steppe desert,desert steppe and wetland meadow;type III is very simply composed of only salinized meadow;type IV is distributed above an elevation of 2300 m,containing mountain steppe,meadow steppe,subalpine meadow and alpine meadow;type V only contains salinized meadow.The results show that with increasing elevation,species combination changes from the xerophytic shrubs,semi-shrubs and herbs distributed in the low altitude zone with arid climate to the cold-tolerant perennial herbs growing in the high altitudinal zone with cold climate.
基金Fund from the Forestry Bureau of Fukang CityThe Director's Fund of the Xinjiang Institute of Ecology and Geology,CAS
文摘The Gurbantunggut Desert is the largest stable and semi-stable sand desert in China, yet few data exist on vegetation pattern and species-environment relationships for these diverse desert landscapes. The sand dunes of the survey area are mainly of the longi- tudinal form from north to south, but checkerboard-shaped and honeycomb-shaped forms are also present, with the height of 10-50 m. We measured vegetation and soil data on north-south transects and compared them with vegetation and soil data on east-west transects. Analysis revealed that the varying trend and strength of the species diversity, dominance and cover of the plant communities in the longitudinal and transverse directions across the landscape are significantly different. The results of CCA ordination show that the microhabitats of soil organic matter （OM）, soil salts （TS）, sorting index （ σ ）, topsoil water-content （SM） and pH relate to the differences in vegetation observed as differences in species assemblage from salt-intolerant ephemerals, micro-subshrubs and subshrubs to salt-tolerant shrubs and micro-arbors. The terrain （alt.） and soil texture （the contents of Mz and Ф 1） affect the spatial differentiation of many species. However, this spatial differentiation is not so marked on transects running longitudinally with the landscape, in the same direction as the dunes. The species of the desert vegetation have formed three assemblages under the action of habitat gradients, relating to three sections running transversely across the landscape, at right angles to the direction of the dune crests. In the mid-east section of the study area the topography is higher, with sand-lands or dune-slopes with coarse particles. Here the dominant vegetation comprises shrubs and subshrubs of Seriphidium santofium and Ephedra distachya, with large numbers of ephemeral and ephemeroid plants of Senecio subdentatus, and Carex physodes in spring and summer. On the soil of the dune-slopes in the mid-west of the study area, with coarse particles and abundant TK, the plant assemblage of Haloxylon persicum, Soranthus meyeri and Agriophyllum squarrosum is developed. The species composition in the east marginal belt of the study area has similar characteristics to the mid-west section. There is no corresponding section in the north-south transects （except for the north and south margins）. This is because the habitats of most plants are located in the middle of the microhabitat gradients in the north-south direction in the desert.
基金Supported by the Forestry Bureau of Fukang City, the Director’s fund of the Xinjiang Institute of Ecology and Geology, CAS and Xinjiang Grassland Project of GEF
文摘In the present research,the authors measured parameters of richness,cover and importance value of ephemeral and ephemeroid plants on south-north and east-west transects in the Gurbantünggüt Desert in early spring,and investigated and analyzed the microhabitats,such as terrain,geomorphology,soil physical-chemical properties and crusts. By comparison,the regional differences in the ephemeral distribution in the desert were revealed. The species of ephemeral plants in the south and center are the richest and those in the west are the poorest in the desert. The cover of ephemeral plants in the mid-south is higher than that in the north,and that in the mid-east is higher than that in the west. The response of ephemeral plants to the spatial variation of the desert habitat forms the population-habitat gradient of ephemeral plants. The characteristics are:(1) In the habitat with higher terrain,coarser textured soil with poorer sorting and correspondingly higher organic matter and lower alkali-saline contents,Carex physoides and Eremopyrum orientale are the dominant ephemeral plants;(2) In the dry habitat with lower terrain,looser textured soil,some organic matter,alkali-saline soil,and developed crust,the ephemeral plants Alyssum linifolium and Erodium oxyrrhynchum are of characteristic of drought and alkali-saline tolerance;(3) In the habitat with lower terrain,some water and more alkali-saline soil,the ephemeral plants Neotorularia torulosa and Hypecoum parviflorum being of alkali-saline tolerance are mainly developed. However,most ephemerals are distributed in a habitat order of higher terrain,some organic,and less alkali-saline soil on the above-mentioned ephemeral population-habitat gradient. The spatial gradient of variation in desert microhabitats is small,and as a whole,the physio-logical character of mesophytism is represented by the desert ephemerals.
