In this paper,based on the common soil erosion model,the Three-River Headwaters region was select for study object. GIS methods are applied to conduct Semi-quantitative assessment for different types of soil erosion,a...In this paper,based on the common soil erosion model,the Three-River Headwaters region was select for study object. GIS methods are applied to conduct Semi-quantitative assessment for different types of soil erosion,and some results are concluded. The water erosion occurs in High Mountain and extra-high mountain of Yushu,Nangqian,Banma and Jiuzhi County in the southeast and south of the Three-River Headwaters region. The degree of erosion is prone to topography,precipitation,river and human activity. The freeze-thaw erosion mainly distributes in the northwest of the Three-River Headwaters region. The area of middle and above middle erosion degree accounts for roughly 50%.展开更多
The Tonle Sap Lake is home to three types of communities： land-based, water-based and land-water based communities, whose livelihoods are dependent on Lake＇s resources. This paper examines how fishing communities in...The Tonle Sap Lake is home to three types of communities： land-based, water-based and land-water based communities, whose livelihoods are dependent on Lake＇s resources. This paper examines how fishing communities in the Tonic Sap Lake make their living in the context of declined resources, increased competition between fishers, the resources politics and the increased trades around the Lake. The paper concludes that in the old day, communities around the lake were related to one another through bartering rice and fish. However, at present, as resources declining, these communities compete over resources, and in doing so, they build relationship and connection with powerful elites including officials, fish traders and the fishing operators, who could protect them in fishing. As a consequence, fishers are trapped in the webs of vicious cycle of poverty, conflicts, corruption and patronage system and exploited and sucked in these webs.展开更多
The resource-based city can divides according to the Israeli resource type and development phase two big standards. The resource-based city economic transformation strategy first should from the macroscopic level, see...The resource-based city can divides according to the Israeli resource type and development phase two big standards. The resource-based city economic transformation strategy first should from the macroscopic level, seek for the regional economic development the new superiority, next should act according to the new regional development favorable condition that establishes the pattern of industrial transformation from the microscopic level.展开更多
This paper examines human impact on stands and individual trees of Pinus yunnanensis growing near the small mountain villages of Pianshui and Yangjuan in southwestern Sichuan Province,China.In an effort to assess whet...This paper examines human impact on stands and individual trees of Pinus yunnanensis growing near the small mountain villages of Pianshui and Yangjuan in southwestern Sichuan Province,China.In an effort to assess whether use of these forests was sustainable,we examined the effects of human use in two ways.First,we directly measured the effect of cutting branches,for fuel and fodder,on tree growth.We hypothesized that branch cutting would negatively impact tree growth.We established 12 plots on four hills and compared 14 pairs of trees,one tree in each pair with an apparently full crown and the other with a considerable portion of the crown removed.Second,we assessed stand and tree properties over a 500 m elevation gradient above the villages where we hypothesized that as elevation increases,stand and tree properties should show fewer human impacts.Although extensive branch cutting reduced the live crown,tree height and diameter,compensatory processes likely enabled trees to recover and to add basal area increments(BAIs) similar to those added by trees with full crowns.Trees and stands close to villages showed less growth and lower basal areas,respectively,than stands and trees at intermediate or distant elevations from villages.Areas relatively close to the villages showed considerable effects of human-related disturbances such as branch cutting,grazing,tree and shrub removal,losses of litter,and human and animal trails.Such areas had increased soil erosion and often loss of the ‘A' horizon.Stands close to villages had younger trees,lower stand basal areas,smaller basal area increments,and more stumps.Our results suggest an increasingly vulnerable interface between occupants of these two villages and their surrounding forests.展开更多
The mountainous hydrological process usually shows high variation to climate change and human action. In the Longitudinal Range-Gorge Region（LRGR）, Southwestern China and Southeast Asian, the transboundary runoff va...The mountainous hydrological process usually shows high variation to climate change and human action. In the Longitudinal Range-Gorge Region（LRGR）, Southwestern China and Southeast Asian, the transboundary runoff variations are much more sensitive and complex under the interaction of climate change, ＂corridor-barrier＂ functions in LRGR,and dams building. In this paper, based on the long hydrological records（1956-2013） from three mainstream hydrological stations in Nu River,Lancang River, and Red River, the region runoff variations were analyzed. The results show out： i） the regional runoff changes were strongly influenced by the ＂Corridor-Barrier＂ functions in LRGR from west to east, the variability extent of annual runoff increased, but tended to decrease after 2009 and the reduced extents also increased; ii） the annual runoff change in the three rivers had high concentration degrees; iii） there were periodicities of 33 years of runoff change in Nu River and Lancang River, and 30 years in Red River, and the lower flow period would continue for 8-9 years in Nu River and Lancang River but only for 4 years in Red River; iv） since 2010, as the two mega dams of Xiaowan and Nuozhadu built in Lancang River mainstream, their variations of annual runoff were quite different. The research results could offer a scientific base for sustainable utilization,conservation, and management of the regional water resources展开更多
Nowadays, mowing has an increasing role in the management of semi-natural and nature conservation areas. Semi-dry grasslands have been planted on cleared areas of forest in the Pannon Mountains, which would be reclaim...Nowadays, mowing has an increasing role in the management of semi-natural and nature conservation areas. Semi-dry grasslands have been planted on cleared areas of forest in the Pannon Mountains, which would be reclaimed by forest without use of the areas by humans. In our work we analysed cleared grasslands. The questions we tried to answer were which changes were caused by different land use, how favourable mowing can be for the purpose of grassland management and nature protection, do the composition of the plant species and the diversity vary within two years when conditions of precipitation are different. In four sampling areas, in 4 × 10 quadrats we registered the plant species and their cover values. We performed a site assessment in April, June and October, 2013-2014. We analysed the data by using cluster and ordination processes and we compared the sampling areas on the basis of the humidity preference and Shannon＇s index of diversity. According to the results, the composition of species and diversity on the analysed areas used for different purposes considerably deviate from each other. Further, we found a difference between two portions of the area whose had minor deviation in water management.展开更多
文摘In this paper,based on the common soil erosion model,the Three-River Headwaters region was select for study object. GIS methods are applied to conduct Semi-quantitative assessment for different types of soil erosion,and some results are concluded. The water erosion occurs in High Mountain and extra-high mountain of Yushu,Nangqian,Banma and Jiuzhi County in the southeast and south of the Three-River Headwaters region. The degree of erosion is prone to topography,precipitation,river and human activity. The freeze-thaw erosion mainly distributes in the northwest of the Three-River Headwaters region. The area of middle and above middle erosion degree accounts for roughly 50%.
文摘The Tonle Sap Lake is home to three types of communities： land-based, water-based and land-water based communities, whose livelihoods are dependent on Lake＇s resources. This paper examines how fishing communities in the Tonic Sap Lake make their living in the context of declined resources, increased competition between fishers, the resources politics and the increased trades around the Lake. The paper concludes that in the old day, communities around the lake were related to one another through bartering rice and fish. However, at present, as resources declining, these communities compete over resources, and in doing so, they build relationship and connection with powerful elites including officials, fish traders and the fishing operators, who could protect them in fishing. As a consequence, fishers are trapped in the webs of vicious cycle of poverty, conflicts, corruption and patronage system and exploited and sucked in these webs.
文摘The resource-based city can divides according to the Israeli resource type and development phase two big standards. The resource-based city economic transformation strategy first should from the macroscopic level, seek for the regional economic development the new superiority, next should act according to the new regional development favorable condition that establishes the pattern of industrial transformation from the microscopic level.
基金Financial support was provided by an Asian Studies Grant to Harrell, NSF - IGERT 0333408the School of Environmental and Forest SciencesUniversity of Washington, Seattle, WA, USA
文摘This paper examines human impact on stands and individual trees of Pinus yunnanensis growing near the small mountain villages of Pianshui and Yangjuan in southwestern Sichuan Province,China.In an effort to assess whether use of these forests was sustainable,we examined the effects of human use in two ways.First,we directly measured the effect of cutting branches,for fuel and fodder,on tree growth.We hypothesized that branch cutting would negatively impact tree growth.We established 12 plots on four hills and compared 14 pairs of trees,one tree in each pair with an apparently full crown and the other with a considerable portion of the crown removed.Second,we assessed stand and tree properties over a 500 m elevation gradient above the villages where we hypothesized that as elevation increases,stand and tree properties should show fewer human impacts.Although extensive branch cutting reduced the live crown,tree height and diameter,compensatory processes likely enabled trees to recover and to add basal area increments(BAIs) similar to those added by trees with full crowns.Trees and stands close to villages showed less growth and lower basal areas,respectively,than stands and trees at intermediate or distant elevations from villages.Areas relatively close to the villages showed considerable effects of human-related disturbances such as branch cutting,grazing,tree and shrub removal,losses of litter,and human and animal trails.Such areas had increased soil erosion and often loss of the ‘A' horizon.Stands close to villages had younger trees,lower stand basal areas,smaller basal area increments,and more stumps.Our results suggest an increasingly vulnerable interface between occupants of these two villages and their surrounding forests.
基金funded by the National Key Research and Development Program of China(Grant No.2016YFA0601600)the Key Project of National Natural Science Foundation of China(Grant No.U1202232)
文摘The mountainous hydrological process usually shows high variation to climate change and human action. In the Longitudinal Range-Gorge Region（LRGR）, Southwestern China and Southeast Asian, the transboundary runoff variations are much more sensitive and complex under the interaction of climate change, ＂corridor-barrier＂ functions in LRGR,and dams building. In this paper, based on the long hydrological records（1956-2013） from three mainstream hydrological stations in Nu River,Lancang River, and Red River, the region runoff variations were analyzed. The results show out： i） the regional runoff changes were strongly influenced by the ＂Corridor-Barrier＂ functions in LRGR from west to east, the variability extent of annual runoff increased, but tended to decrease after 2009 and the reduced extents also increased; ii） the annual runoff change in the three rivers had high concentration degrees; iii） there were periodicities of 33 years of runoff change in Nu River and Lancang River, and 30 years in Red River, and the lower flow period would continue for 8-9 years in Nu River and Lancang River but only for 4 years in Red River; iv） since 2010, as the two mega dams of Xiaowan and Nuozhadu built in Lancang River mainstream, their variations of annual runoff were quite different. The research results could offer a scientific base for sustainable utilization,conservation, and management of the regional water resources
文摘Nowadays, mowing has an increasing role in the management of semi-natural and nature conservation areas. Semi-dry grasslands have been planted on cleared areas of forest in the Pannon Mountains, which would be reclaimed by forest without use of the areas by humans. In our work we analysed cleared grasslands. The questions we tried to answer were which changes were caused by different land use, how favourable mowing can be for the purpose of grassland management and nature protection, do the composition of the plant species and the diversity vary within two years when conditions of precipitation are different. In four sampling areas, in 4 × 10 quadrats we registered the plant species and their cover values. We performed a site assessment in April, June and October, 2013-2014. We analysed the data by using cluster and ordination processes and we compared the sampling areas on the basis of the humidity preference and Shannon＇s index of diversity. According to the results, the composition of species and diversity on the analysed areas used for different purposes considerably deviate from each other. Further, we found a difference between two portions of the area whose had minor deviation in water management.
