Forests exert significant biogeophysical cooling effects(CE)through processes such as increased evapotranspiration,reduced albedo,and enhanced surface roughness.However,little is known about the extent to which elevat...Forests exert significant biogeophysical cooling effects(CE)through processes such as increased evapotranspiration,reduced albedo,and enhanced surface roughness.However,little is known about the extent to which elevation-induced temperature differences bias the observed CE and how this bias interacts with the underlying biogeophysical mechanisms.In this study,we integrated multisensor remote sensing products and Shuttle Radar Topography Mission(SRTM)elevation data on the Google Earth Engine(GEE)platform,and applied a spatial-temporal window regression approach to quantify and correct the sensitivity of land surface temperature(LST)to elevation for forest pixels across China from 2001 to 2022.First,we found that forest LST exhibited a significant negative relationship with elevation,leading to systematic CE overestimation by 0.61 K during the day and 0.60 K at night compared with altitudecorrected CE values.Second,after correction,the CE showed clear spatial heterogeneity,with stronger daytime cooling in tropical(-0.54 K)and temperate forests(-0.24 K),and warming in cold(+0.11 K)and arid regions(+0.53 K),while most regions experienced nighttime warming.Among forest types,evergreen needleleaf forests(ENF)exhibited the strongest daytime cooling(-0.36 K),whereas deciduous broadleaf(DBF)and open shrublands(OS)tended to warm.Third,mechanism analysis revealed that elevation correction strengthened the correlations of CE with leaf area index(LAI)and evapotranspiration,while maintaining a significant negative correlation with albedo,indicating that both radiative and non-radiative processes jointly shape the unbiased CE.These findings provide a more accurate quantification of forest CE by eliminating elevation-induced bias,which providing a more accurate assessment of the climate mitigation potential of forests,which is crucial for developing more effective forest management and ecological restoration strategies.展开更多
在海洋强国战略实施背景下,浮式生产储油卸油装置(Floating Production Storage and Offloading,FPSO)对深远海及海上边际油气田的勘测与开发有着重要意义。基于PatSnap专利数据平台,从时间态势、地域分布、重要申请人和核心技术分类等...在海洋强国战略实施背景下,浮式生产储油卸油装置(Floating Production Storage and Offloading,FPSO)对深远海及海上边际油气田的勘测与开发有着重要意义。基于PatSnap专利数据平台,从时间态势、地域分布、重要申请人和核心技术分类等角度对FPSO生产系统领域专利技术的演化路径进行分析,研究结果表明:FPSO生产系统领域的技术发展具有明显的阶段性和区域集中特征;其技术主要围绕油气水处理、生产装置和储存装置三个领域展开,具体涉及蒸发气体的冷却、回收再利用、再液化处理、上部结构的支撑装置、储罐强度等方面,其中蒸发气处理系统相关技术和储罐结构设计是FPSO生产系统领域的技术重点。展开更多
基于2006-2016年近10年的长期监测数据,对乌江下游两座高坝的修建对底栖动物群落结构的影响效应进行研究.结果表明:大坝蓄水前后底栖动物群落结构发生显著变化,不同时期的群落结构差异明显.蜉蝣目稚虫对生境的剧烈变动不适应,软体动物...基于2006-2016年近10年的长期监测数据,对乌江下游两座高坝的修建对底栖动物群落结构的影响效应进行研究.结果表明:大坝蓄水前后底栖动物群落结构发生显著变化,不同时期的群落结构差异明显.蜉蝣目稚虫对生境的剧烈变动不适应,软体动物田螺科和觹螺科的一些种类对生境的剧烈扰动较为适应,生活史较短的机会主义物种在水库淹没区和坝下河段逐渐定殖下来.建坝以及大坝的运行调度对乌江下游底栖动物的群落结构产生了重大影响,底栖动物群落结构随着时间发生一定程度的演替.在底栖动物所有类群中,软体动物对栖息地的丧失以及流量的剧烈波动具有较高的耐受性,水生昆虫相对较不耐受环境的剧烈变化,而甲壳动物的适应性极强.百分比模式相似性指数(Percent Model Affinity,PMA)的变动趋势可有效地反映大坝对底栖动物群落的影响效应,其均值随离坝距离的增加而呈现逐步增加的趋势,表明大坝调度对水生态造成的负面影响会随着离坝距离的增加而逐步弱化,这与河流不连续体理论(Serial Discontinuity Concept,SDC)的预测趋势基本一致.根据长期监测成果,蜉蝣目扁蜉科、四节蜉科、细裳蜉科以及毛翅目纹石蛾科的种群恢复状况以及PMA指数可作为评估大坝不利影响减缓措施效果的依据.展开更多
基金Under the auspices of National Social Sciences Foundation of China(No.21BJY114)。
文摘Forests exert significant biogeophysical cooling effects(CE)through processes such as increased evapotranspiration,reduced albedo,and enhanced surface roughness.However,little is known about the extent to which elevation-induced temperature differences bias the observed CE and how this bias interacts with the underlying biogeophysical mechanisms.In this study,we integrated multisensor remote sensing products and Shuttle Radar Topography Mission(SRTM)elevation data on the Google Earth Engine(GEE)platform,and applied a spatial-temporal window regression approach to quantify and correct the sensitivity of land surface temperature(LST)to elevation for forest pixels across China from 2001 to 2022.First,we found that forest LST exhibited a significant negative relationship with elevation,leading to systematic CE overestimation by 0.61 K during the day and 0.60 K at night compared with altitudecorrected CE values.Second,after correction,the CE showed clear spatial heterogeneity,with stronger daytime cooling in tropical(-0.54 K)and temperate forests(-0.24 K),and warming in cold(+0.11 K)and arid regions(+0.53 K),while most regions experienced nighttime warming.Among forest types,evergreen needleleaf forests(ENF)exhibited the strongest daytime cooling(-0.36 K),whereas deciduous broadleaf(DBF)and open shrublands(OS)tended to warm.Third,mechanism analysis revealed that elevation correction strengthened the correlations of CE with leaf area index(LAI)and evapotranspiration,while maintaining a significant negative correlation with albedo,indicating that both radiative and non-radiative processes jointly shape the unbiased CE.These findings provide a more accurate quantification of forest CE by eliminating elevation-induced bias,which providing a more accurate assessment of the climate mitigation potential of forests,which is crucial for developing more effective forest management and ecological restoration strategies.
文摘在海洋强国战略实施背景下,浮式生产储油卸油装置(Floating Production Storage and Offloading,FPSO)对深远海及海上边际油气田的勘测与开发有着重要意义。基于PatSnap专利数据平台,从时间态势、地域分布、重要申请人和核心技术分类等角度对FPSO生产系统领域专利技术的演化路径进行分析,研究结果表明:FPSO生产系统领域的技术发展具有明显的阶段性和区域集中特征;其技术主要围绕油气水处理、生产装置和储存装置三个领域展开,具体涉及蒸发气体的冷却、回收再利用、再液化处理、上部结构的支撑装置、储罐强度等方面,其中蒸发气处理系统相关技术和储罐结构设计是FPSO生产系统领域的技术重点。
文摘基于2006-2016年近10年的长期监测数据,对乌江下游两座高坝的修建对底栖动物群落结构的影响效应进行研究.结果表明:大坝蓄水前后底栖动物群落结构发生显著变化,不同时期的群落结构差异明显.蜉蝣目稚虫对生境的剧烈变动不适应,软体动物田螺科和觹螺科的一些种类对生境的剧烈扰动较为适应,生活史较短的机会主义物种在水库淹没区和坝下河段逐渐定殖下来.建坝以及大坝的运行调度对乌江下游底栖动物的群落结构产生了重大影响,底栖动物群落结构随着时间发生一定程度的演替.在底栖动物所有类群中,软体动物对栖息地的丧失以及流量的剧烈波动具有较高的耐受性,水生昆虫相对较不耐受环境的剧烈变化,而甲壳动物的适应性极强.百分比模式相似性指数(Percent Model Affinity,PMA)的变动趋势可有效地反映大坝对底栖动物群落的影响效应,其均值随离坝距离的增加而呈现逐步增加的趋势,表明大坝调度对水生态造成的负面影响会随着离坝距离的增加而逐步弱化,这与河流不连续体理论(Serial Discontinuity Concept,SDC)的预测趋势基本一致.根据长期监测成果,蜉蝣目扁蜉科、四节蜉科、细裳蜉科以及毛翅目纹石蛾科的种群恢复状况以及PMA指数可作为评估大坝不利影响减缓措施效果的依据.
