Over the last decades and centuries,European mountain landscapes have experienced substantial transformations.Natural and anthropogenic LULC changes(land use and land cover changes), especially agro-pastoral activitie...Over the last decades and centuries,European mountain landscapes have experienced substantial transformations.Natural and anthropogenic LULC changes(land use and land cover changes), especially agro-pastoral activities,have directly influenced the spatial organization and composition of European mountain landscapes.For the past sixty years, natural reforestation has been occurring due to a decline in both agricultural production activities and rural population.Stakeholders, to better anticipate future changes,need spatially and temporally explicit models to identify areas at risk of land change and possible abandonment.This paper presents an integrated approach combining forecasting scenarios and a LULC changes simulation model to assess where LULC changes may occur in the Pyrenees Mountains,based on historical LULC trends and a range of future socio-economic drivers.The proposed methodologyconsiders local specificities of the Pyrenean valleys,sub-regional climate and topographical properties,and regional economic policies.Results indicate that some regions are projected to face strong abandonment, regardless of the scenario conditions.Overall, high rates of change are associated with administrative regions where land productivity is highly dependent on socio-economic drivers and climatic and environmental conditions limit intensive(agricultural and/or pastoral) production and profitability.The combination of the results for the four scenarios allows assessments of where encroachment(e.g.colonization by shrublands) and reforestation are the most probable.This assessment intends to provide insight into the potential future development of the Pyrenees to help identify areas that are the most sensitive to change and to guide decision makers to help their management decisions.展开更多
Abstract The author introduces the w-function defined on the considered spacelike graph M. Under the growth conditions w = o（log z） and w = o（r）, two Bernstein type theorems for M in Rm^n＋m are got, where z and r...Abstract The author introduces the w-function defined on the considered spacelike graph M. Under the growth conditions w = o（log z） and w = o（r）, two Bernstein type theorems for M in Rm^n＋m are got, where z and r are the pseudo-Euclidean distance and the distance function on M to some fixed point respectively. As the ambient space is a curved pseudo- Riemannian product of two Riemannian manifolds （∑1,g1） and （∑2,g2） of dimensions n and m, a Bernstein type result for n =2 under some curvature conditions on E1 and E2 and the growth condition w = o（r） is also got. As more general cases, under some curvature conditions on the ambient space and the growth condition w = o（r） or w = o（√r）, the author concludes that if M has parallel mean curvature, then M is maximal.展开更多
基金supported by the MODE RESPYR project(ANR 2010 JCJC 1804-01)founded by the French National Science Agency(ANR)
文摘Over the last decades and centuries,European mountain landscapes have experienced substantial transformations.Natural and anthropogenic LULC changes(land use and land cover changes), especially agro-pastoral activities,have directly influenced the spatial organization and composition of European mountain landscapes.For the past sixty years, natural reforestation has been occurring due to a decline in both agricultural production activities and rural population.Stakeholders, to better anticipate future changes,need spatially and temporally explicit models to identify areas at risk of land change and possible abandonment.This paper presents an integrated approach combining forecasting scenarios and a LULC changes simulation model to assess where LULC changes may occur in the Pyrenees Mountains,based on historical LULC trends and a range of future socio-economic drivers.The proposed methodologyconsiders local specificities of the Pyrenean valleys,sub-regional climate and topographical properties,and regional economic policies.Results indicate that some regions are projected to face strong abandonment, regardless of the scenario conditions.Overall, high rates of change are associated with administrative regions where land productivity is highly dependent on socio-economic drivers and climatic and environmental conditions limit intensive(agricultural and/or pastoral) production and profitability.The combination of the results for the four scenarios allows assessments of where encroachment(e.g.colonization by shrublands) and reforestation are the most probable.This assessment intends to provide insight into the potential future development of the Pyrenees to help identify areas that are the most sensitive to change and to guide decision makers to help their management decisions.
文摘Abstract The author introduces the w-function defined on the considered spacelike graph M. Under the growth conditions w = o（log z） and w = o（r）, two Bernstein type theorems for M in Rm^n＋m are got, where z and r are the pseudo-Euclidean distance and the distance function on M to some fixed point respectively. As the ambient space is a curved pseudo- Riemannian product of two Riemannian manifolds （∑1,g1） and （∑2,g2） of dimensions n and m, a Bernstein type result for n =2 under some curvature conditions on E1 and E2 and the growth condition w = o（r） is also got. As more general cases, under some curvature conditions on the ambient space and the growth condition w = o（r） or w = o（√r）, the author concludes that if M has parallel mean curvature, then M is maximal.
