1923年,美国第一本,也是世界第一本草原管理学方面的教材——RANGE AND PASTURE MANAGEMENT(《草原与放牧地管理学》)出版。本文通过对该书的作者、内容(前言、正文和索引)、对美国草原管理学教育和教材的重要影响、对我国草原管理学同...1923年,美国第一本,也是世界第一本草原管理学方面的教材——RANGE AND PASTURE MANAGEMENT(《草原与放牧地管理学》)出版。本文通过对该书的作者、内容(前言、正文和索引)、对美国草原管理学教育和教材的重要影响、对我国草原管理学同类教材建设的意义进行介绍和论述,以纪念该书出版100周年。展开更多
Aims Grasslands are the world’s most extensive terrestrial ecosystem,and are a major feed source for livestock.Meeting increasing demand for meat and other dairy products in a sustainable manner is a big challenge.At...Aims Grasslands are the world’s most extensive terrestrial ecosystem,and are a major feed source for livestock.Meeting increasing demand for meat and other dairy products in a sustainable manner is a big challenge.At a field scale,Global Positioning System and ground-based sensor technologies provide promising tools for grassland and herd management with high precision.With the growth in availability of spaceborne remote sensing data,it is therefore important to revisit the relevant methods and applications that can exploit this imagery.In this article,we have reviewed the(i)current status of grassland monitoring/observation methods and applications based on satellite remote sensing data,(ii)the technological and methodological developments to retrieve different grassland biophysical parameters and management characteristics(i.e.degradation,grazing intensity)and(iii)identified the key remaining challenges and some new upcoming trends for future development.Important Findings The retrieval of grassland biophysical parameters have evolved in recent years from classical regression analysis to more complex,efficient and robust modeling approaches,driven by satellite data,and are likely to continue to be the most robust method for deriving grassland information,however these require more high quality calibration and validation data.We found that the hypertemporal satellite data are widely used for time series generation,and particularly to overcome cloud contamination issues,but the current low spatial resolution of these instruments precludes their use for field-scale application in many countries.This trend may change with the current rise in launch of satellite constellations,such as RapidEye,Sentinel-2 and even the microsatellites such as those operated by Skybox Imaging.Microwave imagery has not been widely used for grassland applications,and a better understanding of the backscatter behaviour from different phenological stages is needed for more reliable products in cloudy regions.The development of hyperspectral satellite instrumentation and analytical methods will help for more detailed discrimination of habitat types,and the development of tools for greater end-user operation.展开更多
文摘1923年,美国第一本,也是世界第一本草原管理学方面的教材——RANGE AND PASTURE MANAGEMENT(《草原与放牧地管理学》)出版。本文通过对该书的作者、内容(前言、正文和索引)、对美国草原管理学教育和教材的重要影响、对我国草原管理学同类教材建设的意义进行介绍和论述,以纪念该书出版100周年。
基金Teagasc Walsh Fellowship Program for funding this research.
文摘Aims Grasslands are the world’s most extensive terrestrial ecosystem,and are a major feed source for livestock.Meeting increasing demand for meat and other dairy products in a sustainable manner is a big challenge.At a field scale,Global Positioning System and ground-based sensor technologies provide promising tools for grassland and herd management with high precision.With the growth in availability of spaceborne remote sensing data,it is therefore important to revisit the relevant methods and applications that can exploit this imagery.In this article,we have reviewed the(i)current status of grassland monitoring/observation methods and applications based on satellite remote sensing data,(ii)the technological and methodological developments to retrieve different grassland biophysical parameters and management characteristics(i.e.degradation,grazing intensity)and(iii)identified the key remaining challenges and some new upcoming trends for future development.Important Findings The retrieval of grassland biophysical parameters have evolved in recent years from classical regression analysis to more complex,efficient and robust modeling approaches,driven by satellite data,and are likely to continue to be the most robust method for deriving grassland information,however these require more high quality calibration and validation data.We found that the hypertemporal satellite data are widely used for time series generation,and particularly to overcome cloud contamination issues,but the current low spatial resolution of these instruments precludes their use for field-scale application in many countries.This trend may change with the current rise in launch of satellite constellations,such as RapidEye,Sentinel-2 and even the microsatellites such as those operated by Skybox Imaging.Microwave imagery has not been widely used for grassland applications,and a better understanding of the backscatter behaviour from different phenological stages is needed for more reliable products in cloudy regions.The development of hyperspectral satellite instrumentation and analytical methods will help for more detailed discrimination of habitat types,and the development of tools for greater end-user operation.
