Correlated increases in population and dema nd for food over rece nt decades have caused remarkable changes in cropland area globally. Utilizing the latest data product provided by the European Space Agency (ESA), thi...Correlated increases in population and dema nd for food over rece nt decades have caused remarkable changes in cropland area globally. Utilizing the latest data product provided by the European Space Agency (ESA), this paper an alyzes annual trends and spatiotemporal variati ons in cropla nd area and discusses cropla nd con version, I osses, and in creases globally between 1992 and 2015 at a 300 m resoluti on. The results show that the global area of cropla nd in creased rapidly between 1992 and 2004, more slowly between 2004 and 2012, and began to decrease gradually since 2012. First, an increasing trend in cropland area has been maintained solely in Africa;all other regions are characterized by decreasing trends in later periods despite different transition points and change rates. A reduction in cropland area frequently emerged earlier in high-income countries. Second, increase rates in cropland area have largely decreased in recent years while the overall rate of loss has remained almost the same. Hotspot areas of global cropland increases are mainly concentrated around the edge of the Amazon forest, Eurasian Steppe, and Sahara Desert. These hotspot areas of global cropland loss shifted from Europe to Asia while built-up areas have expanded at the expense of cropland.展开更多
Ecological quality is defined as the stability, adaptability and resilience of an ecosystem. Monitoring and assessing ecological quality are important bases for China’s ecological civilization construction. The natio...Ecological quality is defined as the stability, adaptability and resilience of an ecosystem. Monitoring and assessing ecological quality are important bases for China’s ecological civilization construction. The national key research and development program "Technologies and guidelines for monitoring ecological quality of terrestrial ecosystems in China", launched in July 2017, includes plans to study the observation technologies and provide guidelines on the ecological in-situ observation, the regional biodiversity and ecosystem function monitoring and its applications, all of which contribute to national ecological quality assessment. A year after its implementation,some important progress has been achieved, such as building the indicator system for comprehensive monitoring of ecological quality and improvement of the methods, mass data transmission, infrared camera-based monitoring of biodiversity, multi-angle automatic spectral observation systems, and unmanned aerial vehicle(UAV) based desert monitoring. We have organized this special issue and attempted to introduce the monitoring techniques and assessment methods on ecological quality from different perspectives in order to further promote the development of ecology and its observation methods.展开更多
基金National Natural Science Foundation of China(91325302)
文摘Correlated increases in population and dema nd for food over rece nt decades have caused remarkable changes in cropland area globally. Utilizing the latest data product provided by the European Space Agency (ESA), this paper an alyzes annual trends and spatiotemporal variati ons in cropla nd area and discusses cropla nd con version, I osses, and in creases globally between 1992 and 2015 at a 300 m resoluti on. The results show that the global area of cropla nd in creased rapidly between 1992 and 2004, more slowly between 2004 and 2012, and began to decrease gradually since 2012. First, an increasing trend in cropland area has been maintained solely in Africa;all other regions are characterized by decreasing trends in later periods despite different transition points and change rates. A reduction in cropland area frequently emerged earlier in high-income countries. Second, increase rates in cropland area have largely decreased in recent years while the overall rate of loss has remained almost the same. Hotspot areas of global cropland increases are mainly concentrated around the edge of the Amazon forest, Eurasian Steppe, and Sahara Desert. These hotspot areas of global cropland loss shifted from Europe to Asia while built-up areas have expanded at the expense of cropland.
基金The National Key Basic Research and Development Program(2017YFC0503800)
文摘Ecological quality is defined as the stability, adaptability and resilience of an ecosystem. Monitoring and assessing ecological quality are important bases for China’s ecological civilization construction. The national key research and development program "Technologies and guidelines for monitoring ecological quality of terrestrial ecosystems in China", launched in July 2017, includes plans to study the observation technologies and provide guidelines on the ecological in-situ observation, the regional biodiversity and ecosystem function monitoring and its applications, all of which contribute to national ecological quality assessment. A year after its implementation,some important progress has been achieved, such as building the indicator system for comprehensive monitoring of ecological quality and improvement of the methods, mass data transmission, infrared camera-based monitoring of biodiversity, multi-angle automatic spectral observation systems, and unmanned aerial vehicle(UAV) based desert monitoring. We have organized this special issue and attempted to introduce the monitoring techniques and assessment methods on ecological quality from different perspectives in order to further promote the development of ecology and its observation methods.
