Ecosystem is a fundamental organizational unit of the biosphere in which biological communities interact with their non-biological environment through energy flows and material cycles.Ecosystem science is the study of...Ecosystem is a fundamental organizational unit of the biosphere in which biological communities interact with their non-biological environment through energy flows and material cycles.Ecosystem science is the study of patterns,processes,and services of ecosystems.Since the 1990s,rising concerns regarding global climate change,biodiversity loss,ecosystem degradation,and sustainability of the human-dominated biosphere have stimulated the growth of ecosystem science,which is expected to provide systematic solutions to many of these major issues facing human societies.This paper provides a comprehensive review of the current progress in ecosystem science and identifies some key research challenges facing this discipline.We demonstrate that a key feature of the current progress in ecosystem science is its evolution from primarily theoretical explorations toward more systematic,integrative and application-oriented studies.Specifically,five major changes in the discipline over the past several decades can be identified.These include:(1)the expansion of the primary goal from understanding nature to include human activities;(2)the broadening of the research focus from single ecosystem types to macro-ecosystems comprising multiple regional ecosystems;(3)the shifting of research methods from small-scale observations and experiments to large-scale observations,network experiments,and model simulations;(4)the increasing attention to comprehensive integration of ecosystem components,processes,and scales;and(5)the shifting from a primarily biology-oriented focus to an integrated multi-disciplinary scientific field.While ecosystem science still faces many challenges in the future,these directional changes,along with the rapidly enriched research tools and data acquisition capabilities,lay a promising ground for the discipline’s future as a fundamental scientific basis for solving many environmental challenges facing human societies.展开更多
The alpine treeline ecotone is an important component of mountain ecosystems of the Nepal Himalaya; it plays a vital role in the livelihood of indigenous people,and provides ecosystem services. However,the region face...The alpine treeline ecotone is an important component of mountain ecosystems of the Nepal Himalaya; it plays a vital role in the livelihood of indigenous people,and provides ecosystem services. However,the region faces a problem of paucity of data on treeline characteristics at the regional and landscape scales. Therefore,we used Remote Sensing(RS),and Geographic Information Science(GIS) approaches to investigate cross-scale interactions in the treeline ecotone. Additionally,European Space Agency land cover map,International Center for Integrated Mountain Development(ICIMOD) land cover map,ecological map of Nepal,and United States Geological Survey Shuttle Radar Topography Mission-Digital Elevation Model were used to analyze treeline pattern at the regional scale. Digital Globe high-resolution satellite imagery of Barun(eastern Nepal) and Manang(central Nepal) were used to study treeline patterns at the landscape scale. Treeline elevation ranges from 3300-4300 m above sea level. Abies spectabilis,Betula utilis,and Pinus wallichiana are the main treeline-forming species in the Nepal Himalaya. There is an east to west treeline elevationgradient at the regional scale. No slope exposure is observed at the regional scale; however,at the landscape scale,slope exposure is present only in a disturbed area(Manang). Topography and human disturbance are the main treeline controlling factor in Barun and Manang respectively.展开更多
文摘Ecosystem is a fundamental organizational unit of the biosphere in which biological communities interact with their non-biological environment through energy flows and material cycles.Ecosystem science is the study of patterns,processes,and services of ecosystems.Since the 1990s,rising concerns regarding global climate change,biodiversity loss,ecosystem degradation,and sustainability of the human-dominated biosphere have stimulated the growth of ecosystem science,which is expected to provide systematic solutions to many of these major issues facing human societies.This paper provides a comprehensive review of the current progress in ecosystem science and identifies some key research challenges facing this discipline.We demonstrate that a key feature of the current progress in ecosystem science is its evolution from primarily theoretical explorations toward more systematic,integrative and application-oriented studies.Specifically,five major changes in the discipline over the past several decades can be identified.These include:(1)the expansion of the primary goal from understanding nature to include human activities;(2)the broadening of the research focus from single ecosystem types to macro-ecosystems comprising multiple regional ecosystems;(3)the shifting of research methods from small-scale observations and experiments to large-scale observations,network experiments,and model simulations;(4)the increasing attention to comprehensive integration of ecosystem components,processes,and scales;and(5)the shifting from a primarily biology-oriented focus to an integrated multi-disciplinary scientific field.While ecosystem science still faces many challenges in the future,these directional changes,along with the rapidly enriched research tools and data acquisition capabilities,lay a promising ground for the discipline’s future as a fundamental scientific basis for solving many environmental challenges facing human societies.
文摘The alpine treeline ecotone is an important component of mountain ecosystems of the Nepal Himalaya; it plays a vital role in the livelihood of indigenous people,and provides ecosystem services. However,the region faces a problem of paucity of data on treeline characteristics at the regional and landscape scales. Therefore,we used Remote Sensing(RS),and Geographic Information Science(GIS) approaches to investigate cross-scale interactions in the treeline ecotone. Additionally,European Space Agency land cover map,International Center for Integrated Mountain Development(ICIMOD) land cover map,ecological map of Nepal,and United States Geological Survey Shuttle Radar Topography Mission-Digital Elevation Model were used to analyze treeline pattern at the regional scale. Digital Globe high-resolution satellite imagery of Barun(eastern Nepal) and Manang(central Nepal) were used to study treeline patterns at the landscape scale. Treeline elevation ranges from 3300-4300 m above sea level. Abies spectabilis,Betula utilis,and Pinus wallichiana are the main treeline-forming species in the Nepal Himalaya. There is an east to west treeline elevationgradient at the regional scale. No slope exposure is observed at the regional scale; however,at the landscape scale,slope exposure is present only in a disturbed area(Manang). Topography and human disturbance are the main treeline controlling factor in Barun and Manang respectively.
