Bofedales,high-altitude Andean peatlands,are critical to the sustainability of mountain ecosystems and the livelihoods of pastoral communities.This study presents findings from a transdisciplinary research project foc...Bofedales,high-altitude Andean peatlands,are critical to the sustainability of mountain ecosystems and the livelihoods of pastoral communities.This study presents findings from a transdisciplinary research project focused on two bofedal systems,Sorapata and Aychuta,within Bolivia's Sajama National Park.Using vegetation assessments from 2012 to 2018,we identified a marked decline in cushion-forming species(Distichia muscoides and Oxychloe andina),and a clear shift in community composition,indicating a trend toward desiccation.Land cover analyses from 2014 to 2021 revealed a contraction of dense bofedales and an expansion of dry bofedales and bare soil,indicating sustained degradation.These dynamics manifested differently across sites.In Sorapata,degradation was dominant,although localized irrigation practices implemented in 2018 facilitated partial recovery in one sector.These varied trajectories reveal simultaneous processes of decline and recovery.In contrast,Aychuta maintained relatively stable cushion-dominant vegetation,though vegetation surveys and land cover analyses both revealed early shifts in composition and cover associated with climate change.Together,these patterns reveal simultaneous processes of decline,stability,and recovery.Ecological findings align with interviews with indigenous herders,who attribute degradation to reduced precipitation,rising temperatures,and seismic activity,while emphasizing the role of water management in bofedal restoration.Our results highlight the vulnerability of bofedales to climatic and environmental stressors,emphasizing the importance of integrated water management strategies in their conservation under changing climatic conditions.We advocate for transdisciplinary approaches that combine ecological research,integrate multi-year vegetation surveys,remote sensing,and traditional ecological knowledge to enhance our understanding and conservation of these critical socioecological systems.展开更多
Accurate sea surface flux measurements are crucial for understanding the global water and energy cycles. The oceanic evaporation, which is a major component of the global oceanic fresh water flux, is useful for predic...Accurate sea surface flux measurements are crucial for understanding the global water and energy cycles. The oceanic evaporation, which is a major component of the global oceanic fresh water flux, is useful for predicting oceanic circulation and transport. The global Goddard Satellite-based Surface Turbulent Fluxes Version-2 （GSSTF2; July 1987–December 2000） dateset that was o？cially released in 2001 has been widely used by scientific community for global energy and water cycle research, and regional and short period data analyses. We have recently been funded by NASA to resume processing the GSSTF dataset with an objective of continually producing a uniform dataset of sea surface turbulent fluxes, derived from remote sensing data. The dataset is to be reprocessed and brought up-to-date （GSSTF2b） using improved input datasets such as a recently upgraded NCEP/DOE sea surface temperature reanalysis, and an upgraded surface wind and microwave brightness temperature V6 dataset （Version 6） from the Special Sensor Microwave Imager （SSM/I） produced by Remote Sensing Systems （RSS）. A second new product （GSSTF3） is further proposed with a finer temporal （12-h） and spatial （0.25° × 0.25°） resolution. GSSTF2b （July 1987–December 2008） and GSSTF3 （July 1999–December 2009） will be released for the research community to use by late 2009 and early 2011, respectively.展开更多
It is difficulties for the computer simulation method to study radiation regime at large-scale.Simplified coniferous model was investigated in the present study.It makes the computer simulation methods such as L-syste...It is difficulties for the computer simulation method to study radiation regime at large-scale.Simplified coniferous model was investigated in the present study.It makes the computer simulation methods such as L-systems and radiosity-graphics combined method(RGM) more powerful in remote sensing of heterogeneous coniferous forests over a large-scale region.L-systems is applied to render 3-D coniferous forest scenarios,and RGM model was used to calculate BRF(bidirectional reflectance factor) in visible and near-infrared regions.Results in this study show that in most cases both agreed well.Meanwhile at a tree and forest level,the results are also good.展开更多
基金funded by the Chilean National Agency for Research and Development(ANID)(MILENIO–NCS2022_009,FONDAP 1523A0003,and PFCHA/DOCTORADO NACIONAL/2020–21201693)the support of the Universidad de Tarapacá(UTA Mayor 5744-25)+1 种基金the support of the NASA ROSES LCLUC Program,Contract NNH15CN72C(NNH15CN7)the support of ANID Fondecyt Iniciación 11250991-2025。
文摘Bofedales,high-altitude Andean peatlands,are critical to the sustainability of mountain ecosystems and the livelihoods of pastoral communities.This study presents findings from a transdisciplinary research project focused on two bofedal systems,Sorapata and Aychuta,within Bolivia's Sajama National Park.Using vegetation assessments from 2012 to 2018,we identified a marked decline in cushion-forming species(Distichia muscoides and Oxychloe andina),and a clear shift in community composition,indicating a trend toward desiccation.Land cover analyses from 2014 to 2021 revealed a contraction of dense bofedales and an expansion of dry bofedales and bare soil,indicating sustained degradation.These dynamics manifested differently across sites.In Sorapata,degradation was dominant,although localized irrigation practices implemented in 2018 facilitated partial recovery in one sector.These varied trajectories reveal simultaneous processes of decline and recovery.In contrast,Aychuta maintained relatively stable cushion-dominant vegetation,though vegetation surveys and land cover analyses both revealed early shifts in composition and cover associated with climate change.Together,these patterns reveal simultaneous processes of decline,stability,and recovery.Ecological findings align with interviews with indigenous herders,who attribute degradation to reduced precipitation,rising temperatures,and seismic activity,while emphasizing the role of water management in bofedal restoration.Our results highlight the vulnerability of bofedales to climatic and environmental stressors,emphasizing the importance of integrated water management strategies in their conservation under changing climatic conditions.We advocate for transdisciplinary approaches that combine ecological research,integrate multi-year vegetation surveys,remote sensing,and traditional ecological knowledge to enhance our understanding and conservation of these critical socioecological systems.
基金supported by the Making Earth System data records for Use in Research En-vironments (MEaSUREs) Program of NASA Science Mission Directorate-Earth Science Division
文摘Accurate sea surface flux measurements are crucial for understanding the global water and energy cycles. The oceanic evaporation, which is a major component of the global oceanic fresh water flux, is useful for predicting oceanic circulation and transport. The global Goddard Satellite-based Surface Turbulent Fluxes Version-2 （GSSTF2; July 1987–December 2000） dateset that was o？cially released in 2001 has been widely used by scientific community for global energy and water cycle research, and regional and short period data analyses. We have recently been funded by NASA to resume processing the GSSTF dataset with an objective of continually producing a uniform dataset of sea surface turbulent fluxes, derived from remote sensing data. The dataset is to be reprocessed and brought up-to-date （GSSTF2b） using improved input datasets such as a recently upgraded NCEP/DOE sea surface temperature reanalysis, and an upgraded surface wind and microwave brightness temperature V6 dataset （Version 6） from the Special Sensor Microwave Imager （SSM/I） produced by Remote Sensing Systems （RSS）. A second new product （GSSTF3） is further proposed with a finer temporal （12-h） and spatial （0.25° × 0.25°） resolution. GSSTF2b （July 1987–December 2008） and GSSTF3 （July 1999–December 2009） will be released for the research community to use by late 2009 and early 2011, respectively.
基金the Chinese National Natural Science Foundation Project(40701124)the Chinese Hi-tech Research and Development Program Project(2006AA12Z114)
文摘It is difficulties for the computer simulation method to study radiation regime at large-scale.Simplified coniferous model was investigated in the present study.It makes the computer simulation methods such as L-systems and radiosity-graphics combined method(RGM) more powerful in remote sensing of heterogeneous coniferous forests over a large-scale region.L-systems is applied to render 3-D coniferous forest scenarios,and RGM model was used to calculate BRF(bidirectional reflectance factor) in visible and near-infrared regions.Results in this study show that in most cases both agreed well.Meanwhile at a tree and forest level,the results are also good.
