2014年 第0卷 第1期
2014, 0(1): 5-14.
doi: 10.1007/s11769-014-0651-z
摘要:
Awareness of the adverse ecological effects of road and other large construction projects has resulted in a rapidly growing demand to quantitatively predict and evaluate the effects on gene flow among plants and animals in natural habitats. In this study, we evaluated the effects of different road construction scenarios on animal species movement by using the methods of ecological landscape connectivity in the typical regions of Yunnan Province, China. The results showed landscape connectivity levels (Probability of Connectivity (PC)) decreased after road construction and species with lower dispersal abilities were more affected to the subsequent habitat fragmentation. First level roads affected landscape connectivity most significantly. At a distance of 100 m, the PC index decreased more than 50%. Further analysis suggested that the use of landscape connectivity to assess landscape processes revealed the adverse effects on the species movement more effectively compared with the traditional landscape pattern analysis. In addition, we conducted a graph theory and a least-cost modeling discussion, it is obvious that they are powerful tools to represent and analyze landscape networks with respect to related species movement. Network analysis offers a quantitative and simple but effective tool for ecological process assessment and biological conservation on large scales.
Awareness of the adverse ecological effects of road and other large construction projects has resulted in a rapidly growing demand to quantitatively predict and evaluate the effects on gene flow among plants and animals in natural habitats. In this study, we evaluated the effects of different road construction scenarios on animal species movement by using the methods of ecological landscape connectivity in the typical regions of Yunnan Province, China. The results showed landscape connectivity levels (Probability of Connectivity (PC)) decreased after road construction and species with lower dispersal abilities were more affected to the subsequent habitat fragmentation. First level roads affected landscape connectivity most significantly. At a distance of 100 m, the PC index decreased more than 50%. Further analysis suggested that the use of landscape connectivity to assess landscape processes revealed the adverse effects on the species movement more effectively compared with the traditional landscape pattern analysis. In addition, we conducted a graph theory and a least-cost modeling discussion, it is obvious that they are powerful tools to represent and analyze landscape networks with respect to related species movement. Network analysis offers a quantitative and simple but effective tool for ecological process assessment and biological conservation on large scales.
2014, 0(1): 15-27.
doi: 10.1007/s11769-014-0652-y
摘要:
The structure and function of network is a central issue in landscape ecology. Road networks with hierarchical structure are crucial for understanding landscape dynamics. In this study, we compared the distribution of national road, provincial road, county road and rural road in the Three Parallel Rivers Region (TPRR) in Yunnan Province of China, and estimated the effect of roads (and other factors) on the spatial patterns of land use and land cover with logistic regression. In addition, we analyzed the land use and land cover change (LUCC) and landscape fragmentation in 1989-2005 along a buffer zone of the primary traffic corridor, national road G214. The results showed that, county and rural roads had much higher percentage of length extending into more natural habitats at higher elevation and steeper slope, compared with the higher level roads in this region. While the distributions of natural land cover types were dominated by environmental factors, human land use types i.e., building land and farmland types were significantly related with roads, linking more closely with lower level roads. The LUCC dynamics (1989-2005) of the G214 buffer zone showed a general trend of land transformation from conifer forests and valley arid shrubs to building land and farmland, and from ice and snow to alpine shrubs and forests. With the length of G214 unchanged during the time, the overall landscape pattern changed little in the buffer zone, but habitat fragmentation and area decrease had occurred for the natural vegetation types, in contrast to patch mergence and expansion of human land use types, and landscape fragmentation was intensified above 2500 m a.s.l. but declined below the elevation. The results indicated the dynamics of landscape composition and patch type level distribution in spite of the stability of the overall landscape pattern, and implied the potential role of roads, especially the low level roads on landscape changes.
The structure and function of network is a central issue in landscape ecology. Road networks with hierarchical structure are crucial for understanding landscape dynamics. In this study, we compared the distribution of national road, provincial road, county road and rural road in the Three Parallel Rivers Region (TPRR) in Yunnan Province of China, and estimated the effect of roads (and other factors) on the spatial patterns of land use and land cover with logistic regression. In addition, we analyzed the land use and land cover change (LUCC) and landscape fragmentation in 1989-2005 along a buffer zone of the primary traffic corridor, national road G214. The results showed that, county and rural roads had much higher percentage of length extending into more natural habitats at higher elevation and steeper slope, compared with the higher level roads in this region. While the distributions of natural land cover types were dominated by environmental factors, human land use types i.e., building land and farmland types were significantly related with roads, linking more closely with lower level roads. The LUCC dynamics (1989-2005) of the G214 buffer zone showed a general trend of land transformation from conifer forests and valley arid shrubs to building land and farmland, and from ice and snow to alpine shrubs and forests. With the length of G214 unchanged during the time, the overall landscape pattern changed little in the buffer zone, but habitat fragmentation and area decrease had occurred for the natural vegetation types, in contrast to patch mergence and expansion of human land use types, and landscape fragmentation was intensified above 2500 m a.s.l. but declined below the elevation. The results indicated the dynamics of landscape composition and patch type level distribution in spite of the stability of the overall landscape pattern, and implied the potential role of roads, especially the low level roads on landscape changes.
2014, 0(1): 28-38.
doi: 10.1007/s11769-014-0653-x
摘要:
Roads are conspicuous components in a river landscape; however, their impacts on river landscape patterns and ecological processes have not been systematically studied at the watershed scale. In this paper, the Lancang River Valley in Yunnan Province, China was selected as a case to study road lateral disconnection and crossing impacts and identify river-road network interaction. This study was primarily focused on the road impacts on soil erosion intensity and patch density by using GIS analysis at different scales and explored their distribution with terrain factors. The results showed that river density revealed spatial autocorrelation although both of the roads and rivers were distributed unevenly in the valley. The lateral road (road curvature ≥ 1.1) proportion correlated with soil erosion intensity (p ≤ 0.01) at the small sub-basin scale. Soil erosion intensity decreased with increasing lateral road buffer width. Light erosion generally accounted for a large proportion of the erosion in the lateral road buffer zones (1.0-4.0 km), while higher class lateral roads imposed greater impacts on soil erosion than lower class roads, which primarily had a moderate erosion level. In addition, the results of road-river intersection density indicated that road crossing impacts were significantly correlated with patch density at the small sub-basin scale. Topography factor (percent of slope > 25° in each sub-basin had a close relationship with the ratio of total length of road line with curvature value ≥ 1.1 to the total number of intersections. The correlation (p ≤ 0.01) between road impacts and terrain factor revealed that topography affected the road impact distribution in the Lancang River Valley.
Roads are conspicuous components in a river landscape; however, their impacts on river landscape patterns and ecological processes have not been systematically studied at the watershed scale. In this paper, the Lancang River Valley in Yunnan Province, China was selected as a case to study road lateral disconnection and crossing impacts and identify river-road network interaction. This study was primarily focused on the road impacts on soil erosion intensity and patch density by using GIS analysis at different scales and explored their distribution with terrain factors. The results showed that river density revealed spatial autocorrelation although both of the roads and rivers were distributed unevenly in the valley. The lateral road (road curvature ≥ 1.1) proportion correlated with soil erosion intensity (p ≤ 0.01) at the small sub-basin scale. Soil erosion intensity decreased with increasing lateral road buffer width. Light erosion generally accounted for a large proportion of the erosion in the lateral road buffer zones (1.0-4.0 km), while higher class lateral roads imposed greater impacts on soil erosion than lower class roads, which primarily had a moderate erosion level. In addition, the results of road-river intersection density indicated that road crossing impacts were significantly correlated with patch density at the small sub-basin scale. Topography factor (percent of slope > 25° in each sub-basin had a close relationship with the ratio of total length of road line with curvature value ≥ 1.1 to the total number of intersections. The correlation (p ≤ 0.01) between road impacts and terrain factor revealed that topography affected the road impact distribution in the Lancang River Valley.
2014, 0(1): 39-49.
doi: 10.1007/s11769-014-0654-9
摘要:
Road network is a critical component of public infrastructure, and the supporting system of social and economic development. Based on a modified kernel density estimate (KDE) algorithm, this study evaluated the road service capacity provided by a road network composed of multi-level roads (i.e. national, provincial, county and rural roads), by taking account of the differences of effect extent and intensity for roads of different levels. Summarized at town scale, the population burden and the annual rural economic income of unit road service capacity were used as the surrogates of social and economic demands for road service. This method was applied to the road network of the Three Parallel River Region, the northwestern Yunnan Province, China to evaluate the development of road network in this region. In results, the total road length of this region in 2005 was 3.70 × 104 km, and the length ratio between national, provincial, county and rural roads was 1:2:8:47. From 1989 to 2005, the regional road service capacity increased by 13.1%, of which the contributions from the national, provincial, county and rural roads were 11.1%, 19.4%, 22.6%, and 67.8%, respectively, revealing the effect of‘All Village Accessible’policy of road development in the mountainous regions in the last decade. The spatial patterns of population burden and economic requirement of unit road service suggested that the areas farther away from the national and provincial roads have higher road development priority (RDP). Based on the modified KDE model and the framework of RDP evaluation, this study provided a useful approach for developing an optimal plan of road development at regional scale.
Road network is a critical component of public infrastructure, and the supporting system of social and economic development. Based on a modified kernel density estimate (KDE) algorithm, this study evaluated the road service capacity provided by a road network composed of multi-level roads (i.e. national, provincial, county and rural roads), by taking account of the differences of effect extent and intensity for roads of different levels. Summarized at town scale, the population burden and the annual rural economic income of unit road service capacity were used as the surrogates of social and economic demands for road service. This method was applied to the road network of the Three Parallel River Region, the northwestern Yunnan Province, China to evaluate the development of road network in this region. In results, the total road length of this region in 2005 was 3.70 × 104 km, and the length ratio between national, provincial, county and rural roads was 1:2:8:47. From 1989 to 2005, the regional road service capacity increased by 13.1%, of which the contributions from the national, provincial, county and rural roads were 11.1%, 19.4%, 22.6%, and 67.8%, respectively, revealing the effect of‘All Village Accessible’policy of road development in the mountainous regions in the last decade. The spatial patterns of population burden and economic requirement of unit road service suggested that the areas farther away from the national and provincial roads have higher road development priority (RDP). Based on the modified KDE model and the framework of RDP evaluation, this study provided a useful approach for developing an optimal plan of road development at regional scale.
2014, 0(1): 50-59.
doi: 10.1007/s11769-014-0655-8
摘要:
Traditionally, patch-based analysis at the landscape scale fragmentation has been used in the study of landscape ecology while the study of boundary and node has not been considered as much detail until recently. This study investigated the possibility of applying boundary-and node-based methods in landscape pattern analysis to the upper reaches of the Minjiang River in the southwestern China. Boundary-based and node-based landscape indices were selected to be used in analyzing changes in landscape patterns, and the results were compared with analysis using traditional pattern indices. We compared the responses of patch-area-based, boundary-length-based and node-number-based indices, and concluded that boundary-based and node-based indices are more sensitive to disturbance than patch-based indices with various patterns, and node-based indices are even more sensitive than boundary-based ones. Thus, the results suggest that boundary-based and node-based pattern analysis methods provide helpful supplementary information to traditional patch-based pattern analysis methods. The results about pattern dynamics of landscapes in the upper reaches of the Minjiang River based on boundaries and nodes showed that with human disturbance, the dominance of forest landscape was weakened by other landscape types; thus the landscape pattern of the study area became more homogeneous and the boundary network became more complex. These changes further augmented disturbance interfaces in the landscape and increased the possibilities of further landscape fragmentation.
Traditionally, patch-based analysis at the landscape scale fragmentation has been used in the study of landscape ecology while the study of boundary and node has not been considered as much detail until recently. This study investigated the possibility of applying boundary-and node-based methods in landscape pattern analysis to the upper reaches of the Minjiang River in the southwestern China. Boundary-based and node-based landscape indices were selected to be used in analyzing changes in landscape patterns, and the results were compared with analysis using traditional pattern indices. We compared the responses of patch-area-based, boundary-length-based and node-number-based indices, and concluded that boundary-based and node-based indices are more sensitive to disturbance than patch-based indices with various patterns, and node-based indices are even more sensitive than boundary-based ones. Thus, the results suggest that boundary-based and node-based pattern analysis methods provide helpful supplementary information to traditional patch-based pattern analysis methods. The results about pattern dynamics of landscapes in the upper reaches of the Minjiang River based on boundaries and nodes showed that with human disturbance, the dominance of forest landscape was weakened by other landscape types; thus the landscape pattern of the study area became more homogeneous and the boundary network became more complex. These changes further augmented disturbance interfaces in the landscape and increased the possibilities of further landscape fragmentation.
2014, 0(1): 60-70.
doi: 10.1007/s11769-014-0656-7
摘要:
Many nature reserves are established to protect the habitat needs of particular endangered species of interest but their effectiveness for protecting other species is questionable. In this study, this effectiveness was evaluated in a nature reserve network located in the Qinling Mountains, Shaanxi Province, China. The network of reserves was established mainly for the conservation of the giant panda, a species considered as a surrogate for the conservation of many other endangered species in the region. The habitat suitability of nine protected species, including the giant panda, was modeled by using Maximum Entropy (MAXENT) and their spatial congruence was analyzed. Habitat suitability of these species was also overlapped with nature reserve boundaries and their management zones (i.e., core, buffer and experimental zones). Results show that in general the habitat of the giant panda constitutes a reasonable surrogate of the habitat of other protected species, and giant panda reserves protect a relatively high proportion of the habitat of other protected species. Therefore, giant panda habitat conservation also allows the conservation of the habitat of other protected species in the region. However, a large area of suitable habitat was excluded from the nature reserve network. In addition, four species exhibited a low proportion of highly suitable habitat inside the core zones of nature reserves. It suggests that a high proportion of suitable habitat of protected species not targeted for conservation is located in the experimental and buffer zones, thus, is being affected by human activities. To increase their conservation effectiveness, nature reserves and their management zones need to be re-examined in order to include suitable habitat of more endangered species. The procedures described in this study can be easily implemented for the conservation of many endangered species not only in China but in many other parts of the world.
Many nature reserves are established to protect the habitat needs of particular endangered species of interest but their effectiveness for protecting other species is questionable. In this study, this effectiveness was evaluated in a nature reserve network located in the Qinling Mountains, Shaanxi Province, China. The network of reserves was established mainly for the conservation of the giant panda, a species considered as a surrogate for the conservation of many other endangered species in the region. The habitat suitability of nine protected species, including the giant panda, was modeled by using Maximum Entropy (MAXENT) and their spatial congruence was analyzed. Habitat suitability of these species was also overlapped with nature reserve boundaries and their management zones (i.e., core, buffer and experimental zones). Results show that in general the habitat of the giant panda constitutes a reasonable surrogate of the habitat of other protected species, and giant panda reserves protect a relatively high proportion of the habitat of other protected species. Therefore, giant panda habitat conservation also allows the conservation of the habitat of other protected species in the region. However, a large area of suitable habitat was excluded from the nature reserve network. In addition, four species exhibited a low proportion of highly suitable habitat inside the core zones of nature reserves. It suggests that a high proportion of suitable habitat of protected species not targeted for conservation is located in the experimental and buffer zones, thus, is being affected by human activities. To increase their conservation effectiveness, nature reserves and their management zones need to be re-examined in order to include suitable habitat of more endangered species. The procedures described in this study can be easily implemented for the conservation of many endangered species not only in China but in many other parts of the world.
2014, 0(1): 71-82.
doi: 10.1007/s11769-014-0657-6
摘要:
Formulation of different ecological zone plans according to the corresponding protection targets and the necessity of proper conservation policy is one of the measures to achieve the goal of ecological conservation in China. In order to clarify the interrelation among key ecological zone plans, this paper carried out the research on spatial relation of priority areas of biodiversity conservation and three key ecological areas (key ecological function areas, key regions of ecological service function, national nature reserves) and the research on ecological conditions, based on multi-scale ecological spatial theme information, which incorporates elements like ecological quality and type, and by the aid of spatial information analysis and GIS modeling. The results showed a contrastively fine spatial consistency with 68.8% of priority areas of biodiversity conservation overlapping with three key ecological areas. Although the environment in priority areas of biodiversity conservation were in good conditions, protection pressure is also increasing, powerful supervision and protection should not be ignored. The environmental conditions in the overlapping areas, as a whole, were superior to those in the non-overlapping areas. Since two areas have different characteristics, targeted protection measures should be formulated based on this difference, which will be very important for biodiversity conservation in priority areas of biodiversity conservation.
Formulation of different ecological zone plans according to the corresponding protection targets and the necessity of proper conservation policy is one of the measures to achieve the goal of ecological conservation in China. In order to clarify the interrelation among key ecological zone plans, this paper carried out the research on spatial relation of priority areas of biodiversity conservation and three key ecological areas (key ecological function areas, key regions of ecological service function, national nature reserves) and the research on ecological conditions, based on multi-scale ecological spatial theme information, which incorporates elements like ecological quality and type, and by the aid of spatial information analysis and GIS modeling. The results showed a contrastively fine spatial consistency with 68.8% of priority areas of biodiversity conservation overlapping with three key ecological areas. Although the environment in priority areas of biodiversity conservation were in good conditions, protection pressure is also increasing, powerful supervision and protection should not be ignored. The environmental conditions in the overlapping areas, as a whole, were superior to those in the non-overlapping areas. Since two areas have different characteristics, targeted protection measures should be formulated based on this difference, which will be very important for biodiversity conservation in priority areas of biodiversity conservation.
2014, 0(1): 83-92.
doi: 10.1007/s11769-014-0658-5
摘要:
Poverty reduction and environmental protection are two global tasks for sustainable development. The study perspective has changed over time, from narrowly focusing on poverty reduction to comprehensively strengthening human-welfare. We reviewed key references targeting the theoretical content and practical approach relying on poverty, environment protection and ecosystem services. We discussed the contradicting views on the relationship of poverty and environmental degradation, and then illustrated the study progress of a cutting-age topic-ecosystem services which pave a way to address poverty reduction and environmental protection together. At last, we investigated essential factors that affect the development and environmental protection. Considering the evolution of the concept of poverty, we found that the environment has occupied an increasing proportion in the cognizance of poverty. The relationship between poverty and environmental degradation is regional uniqueness. In practical aspect, projects based on the management and valuation assessment of ecosystem services draw researchers' attention all over the world. The appropriate scale, essential economic incentives, morality, law and social equality are key factors affecting individuals' decisions which directly relate to the sustainable development.
Poverty reduction and environmental protection are two global tasks for sustainable development. The study perspective has changed over time, from narrowly focusing on poverty reduction to comprehensively strengthening human-welfare. We reviewed key references targeting the theoretical content and practical approach relying on poverty, environment protection and ecosystem services. We discussed the contradicting views on the relationship of poverty and environmental degradation, and then illustrated the study progress of a cutting-age topic-ecosystem services which pave a way to address poverty reduction and environmental protection together. At last, we investigated essential factors that affect the development and environmental protection. Considering the evolution of the concept of poverty, we found that the environment has occupied an increasing proportion in the cognizance of poverty. The relationship between poverty and environmental degradation is regional uniqueness. In practical aspect, projects based on the management and valuation assessment of ecosystem services draw researchers' attention all over the world. The appropriate scale, essential economic incentives, morality, law and social equality are key factors affecting individuals' decisions which directly relate to the sustainable development.
2014, 0(1): 93-103.
doi: 10.1007/s11769-014-0659-4
摘要:
The development of modern agriculture has resulted in much homogenization of the landscape consisting of large patches of farmland, so small remnant non-crop habitats especially linear corridors play an important role in the conservation of species and the maintenance of ecosystem functions. However, little attention has been paid to the effects of corridors structural characteristics on the plant species restricted to such habitats. In this study, we selected three types of corridors including ditch, hedgerow and road, and analyzed their structural characteristics. The plant species presented in these corridors were investigated, and the species diversity, abundance and frequency were estimated. Moreover, spatial arrangements of corridors were classified into different types to discuss whether there were significant effects of corridor network on plant distribution. The results show that three types of corridors have different effects on plant species composition and diversity. The one-one combined corridor networks and total network associated by three corridors have more complex structural features than each single type of corridor. However, there is no strong correlation between the corridor networks with their plant species. We suggest that carrying out a pointed vegetation survey at corridor intersections to further test the relationships between structural features of corridor and plants is necessary.
The development of modern agriculture has resulted in much homogenization of the landscape consisting of large patches of farmland, so small remnant non-crop habitats especially linear corridors play an important role in the conservation of species and the maintenance of ecosystem functions. However, little attention has been paid to the effects of corridors structural characteristics on the plant species restricted to such habitats. In this study, we selected three types of corridors including ditch, hedgerow and road, and analyzed their structural characteristics. The plant species presented in these corridors were investigated, and the species diversity, abundance and frequency were estimated. Moreover, spatial arrangements of corridors were classified into different types to discuss whether there were significant effects of corridor network on plant distribution. The results show that three types of corridors have different effects on plant species composition and diversity. The one-one combined corridor networks and total network associated by three corridors have more complex structural features than each single type of corridor. However, there is no strong correlation between the corridor networks with their plant species. We suggest that carrying out a pointed vegetation survey at corridor intersections to further test the relationships between structural features of corridor and plants is necessary.
2014, 0(1): 104-112.
doi: 10.1007/s11769-013-0647-0
摘要:
The altitudinal pattern of vegetation is usually identified by field surveys, however, these can only provide discrete data on a local mountain. Few studies identifying and analyzing the altitudinal vegetation pattern on a regional scale are available. This study selected central Inner Mongolia as the study area, presented a method for extracting vegetation patterns in altitudinal and horizontal directions. The data included a vegetation map at a 1:1 000 000 scale and a digital elevation model at a 1:250 000 scale. The three-dimensional vegetation pattern indicated the distribution probability for each vegetation type and the transition zones between different vegetation landscapes. From low to high elevations, there were five vegetation types in the southern mountain flanks, including the montane steppe, broad-leaved forest, coniferous mixed forest, montane dwarf-scrub and sub-alpine shrub-meadow. Correspondingly, only four vegetation types were found in the northern flanks, except for the montane steppe. This study could provide a general model for understanding the complexity and diversity of mountain environment and landscape.
The altitudinal pattern of vegetation is usually identified by field surveys, however, these can only provide discrete data on a local mountain. Few studies identifying and analyzing the altitudinal vegetation pattern on a regional scale are available. This study selected central Inner Mongolia as the study area, presented a method for extracting vegetation patterns in altitudinal and horizontal directions. The data included a vegetation map at a 1:1 000 000 scale and a digital elevation model at a 1:250 000 scale. The three-dimensional vegetation pattern indicated the distribution probability for each vegetation type and the transition zones between different vegetation landscapes. From low to high elevations, there were five vegetation types in the southern mountain flanks, including the montane steppe, broad-leaved forest, coniferous mixed forest, montane dwarf-scrub and sub-alpine shrub-meadow. Correspondingly, only four vegetation types were found in the northern flanks, except for the montane steppe. This study could provide a general model for understanding the complexity and diversity of mountain environment and landscape.
2014, 0(1): 113-125.
doi: 10.1007/s11769-014-0660-y
摘要:
The protecting requirements and functional connectivity of species in isolated habitat patches are crucial factors of eco-network planning. This study aimed to improve the method of eco-network planning for species conservation. Ecoprofiling was used to group the species by similar behavior types, namely, choice of ecosystem, area requirement, and short distance dispersal abilities. A least-cost model was used to simulate the optimal corridor location to maintain functional connectivity. A combination of ecoprofile and least-cost model was hired to develop an eco-network that promoted species conservation. A case study was also conducted in Beijing, China. In addition to the required ecosystem, habitat area is an important parameter for habitat extraction. Habitat area can remove noise habitat patches because of lacking area. Short-distance dispersal can be used to identify corridor requirements and avoid unnecessary building requirements. Species with various dispersal abilities exhibit significant differences in terms of corridor length and location requirement. Habitat isolation is the main threat for weakly mobile species, and habitat loss is the major risk of mobile species protection. Different species groups also exhibit distinct landscape pattern demands for an eco-network, and the eco-network planning based on specific species can not protect other species. We proposed that a combination of ecoprofile and least-cost model improved the efficiency of species conservation by eco-network planning.
The protecting requirements and functional connectivity of species in isolated habitat patches are crucial factors of eco-network planning. This study aimed to improve the method of eco-network planning for species conservation. Ecoprofiling was used to group the species by similar behavior types, namely, choice of ecosystem, area requirement, and short distance dispersal abilities. A least-cost model was used to simulate the optimal corridor location to maintain functional connectivity. A combination of ecoprofile and least-cost model was hired to develop an eco-network that promoted species conservation. A case study was also conducted in Beijing, China. In addition to the required ecosystem, habitat area is an important parameter for habitat extraction. Habitat area can remove noise habitat patches because of lacking area. Short-distance dispersal can be used to identify corridor requirements and avoid unnecessary building requirements. Species with various dispersal abilities exhibit significant differences in terms of corridor length and location requirement. Habitat isolation is the main threat for weakly mobile species, and habitat loss is the major risk of mobile species protection. Different species groups also exhibit distinct landscape pattern demands for an eco-network, and the eco-network planning based on specific species can not protect other species. We proposed that a combination of ecoprofile and least-cost model improved the efficiency of species conservation by eco-network planning.
2014, 0(1): 126-136.
doi: 10.1007/s11769-013-0635-4
摘要:
This article presents the findings of a study of the spheres of urban influence with regard to all cities in China (not including Hong Kong, Macau and Taiwan Province of China) in the years 1990, 2000 and 2009. An optimized gravity model with comprehensive time distance was used to carry out a detailed analysis of the spatial patterns of Chinese spheres of urban influence and the spatial characteristics of urban agglomerations. Such urban agglomerations are characterized by high density population and a developed economy, which are also considered as the national competition unit. This paper initially identifies four spatial patterns of urban agglomerations based on the spatial layout of city groups during their evolution. Some basic characteristics of urban agglomerations are outlined, including the number of cities, the size of cities and the functions of urban centers. These characteristics are examined by using statistical methods and Geographic Information System (GIS). The main findings from this research are that the development stages and structures of urban agglomerations in China vary significantly. It is also clear that the stages and evolution of spatial patterns are strongly affected and dominated by both policy and location factors.
This article presents the findings of a study of the spheres of urban influence with regard to all cities in China (not including Hong Kong, Macau and Taiwan Province of China) in the years 1990, 2000 and 2009. An optimized gravity model with comprehensive time distance was used to carry out a detailed analysis of the spatial patterns of Chinese spheres of urban influence and the spatial characteristics of urban agglomerations. Such urban agglomerations are characterized by high density population and a developed economy, which are also considered as the national competition unit. This paper initially identifies four spatial patterns of urban agglomerations based on the spatial layout of city groups during their evolution. Some basic characteristics of urban agglomerations are outlined, including the number of cities, the size of cities and the functions of urban centers. These characteristics are examined by using statistical methods and Geographic Information System (GIS). The main findings from this research are that the development stages and structures of urban agglomerations in China vary significantly. It is also clear that the stages and evolution of spatial patterns are strongly affected and dominated by both policy and location factors.
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