In the Northwest Pacific Ocean, the squid jigging fisheries from China, Japan and other countries and regions have targeted the west winter-spring cohort of neon flying squid(Ommastrephes bartramii) from August to N...In the Northwest Pacific Ocean, the squid jigging fisheries from China, Japan and other countries and regions have targeted the west winter-spring cohort of neon flying squid(Ommastrephes bartramii) from August to November since the 1970 s. This squid is a short-lived ecological opportunist with a life-span of about one year,and its population is labile and recruitment variability is driven by the environment or climate change. This variability provides a challenge for ones to forecast the key habitats affected by climate change. The catch data of O. bartramii from Chinese squid jigging fishery and the satellite-derived sea surface temperature(SST) data are used in the Northwest Pacific Ocean from August to November of 1998 to 2004, the SST preferences of O.bartramii corresponding to high values of catch per fishing day(CPUE) are determined and monthly potential habitats are predicted using a histogram analysis of the SST data. The possible changes in the potential habitats of O. bartramii in the Northwest Pacific Ocean are estimated under four climate change scenarios based on the Fourth Assessment Report(AR4) of the Intergovernmental Panel on Climate Change, i.e., 0.5, 1, 2 and 4°C increases in the SST because of the climate change. The results reveal an obvious poleward shift of the potential habitats of O. bartramii in the Northwest Pacific Ocean.展开更多
Understanding the spatial distribution of plant species and their dynamic changes in arid areas is crucial for addressing the challenges posed by climate change.Haloxylon ammodendron shelterbelts are essential for the...Understanding the spatial distribution of plant species and their dynamic changes in arid areas is crucial for addressing the challenges posed by climate change.Haloxylon ammodendron shelterbelts are essential for the protection of plant resources and the control of desertification in Central Asia.Thus far,the potential suitable habitats of H.ammodendron in Central Asia are still uncertain in the future under global climate change conditions.This study utilised the maximum entropy(MaxEnt)model to combine the current distribution data of H.ammodendron with its growth-related data to analyze the potential distribution pattern of H.ammodendron across Central Asia.The results show that there are suitable habitats of H.ammodendron in the Aralkum Desert,northern slopes of the Tianshan Mountains,and the upstream of the Tarim River and western edge of the Taklimakan Desert in the Tarim Basin under the current climate conditions.The period from 2021 to 2040 is projected to undergo significant changes in the suitable habitat area of H.ammodendron in Central Asia,with a projected 15.0% decrease in the unsuitable habitat area.Inland areas farther from the ocean,such as the Caspian Sea and Aralkum Desert,will continue to experience a decrease in the suitable habitats of H.ammodendron.Regions exhibiting frequent fluctuations in the habitat suitability levels are primarily found along the axis stretching from Astana to Kazakhskiy Melkosopochnik in Kazakhstan.These regions can transition into suitable habitats under varying climate conditions,requiring the implementation of appropriate human intervention measures to prevent desertification.Future climate conditions are expected to cause an eastward shift in the geometric centre of the potential suitable habitats of H.ammodendron,with the extent of this shift amplifying alongside more greenhouse gas emissions.This study can provide theoretical support for the spatial configuration of H.ammodendron shelterbelts and desertification control in Central Asia,emphasising the importance of proactive measures to adapt to climate change in the future.展开更多
The general aim of this study is to find the relationship between the panda distribution and human activities. Comparison of the potential panda habitat and the real panda distribution shows a difference between them....The general aim of this study is to find the relationship between the panda distribution and human activities. Comparison of the potential panda habitat and the real panda distribution shows a difference between them. Seven human activities were identified and analyzed. They are settlements, farming, road construction, firewood collection, timber production, mining and Chinese medicinal plant collection. The spatial distributions of these activities were characterized. The analysis of their spatial distributions and the pandas' habitat and distribution revealed that there is a relation existing between the human activities and the panda distribution, and the Giant Pandas have disappeared from the areas where the human activities are concentrated. GIS is the main tool used in this study to collect, store, retrieve, transform and present the spatial data of human activities and panda habitat and distribution in Wolong Nature Reserve.展开更多
Background:Large-scale hunting and various anthropogenic pressures in the recent past have pushed the Asiatic caracal(Caracal caracal schmitzi),an elusive medium-sized and locally threatened felid species towards loca...Background:Large-scale hunting and various anthropogenic pressures in the recent past have pushed the Asiatic caracal(Caracal caracal schmitzi),an elusive medium-sized and locally threatened felid species towards local extinction in India.Though widely distributed historically,it has been sparsely reported from several regions of central and northern states in India till twentieth century.Later,the species distribution became confined only to the states of Rajasthan,Gujarat and Madhya Pradesh,which have had reported sightings in the twenty-first century.In order to highlight the potentially suitable habitats for Asiatic caracals in India,we targeted forth-filtering of the spatial model ensemble by creating and utilizing the validated and spatially thinned species presence information(n=69)and related ecological variables(aridity,NDVI,precipitation seasonality,temperature seasonality,terrain ruggedness),filtered with anthropological variable(nightlight).Results:Out of eight spatial prediction models,the two most parsimonious models,Random Forest(AUC 0.91)and MaxEnt(AUC 0.89)were weighted and ensembled.The ensemble model indicated several clustered habitats,covering 1207.83 km^(2)areas in Kachchh(Gujarat),Aravalli mountains(Rajasthan),Malwa plateau(Rajasthan and Madhya Pradesh),and Bundelkhand region(Madhya Pradesh)as potentially suitable habitats for caracals.Output probabilities of pixels were further regressed with converted vegetation height data within selected highly potential habitats,i.e.,Ranthambore Kuno Landscape(RKL)(suitability~0.44+0.03(vegetation height)^(**),R^(2)=0.27).The regression model inferred a significant positive relation between vegetation height and habitat suitability,hence the lowest ordinal class out of three classes of converted vegetation height was masked out from the RKL,which yielded in an area of 567 km^(2) as potentially highly suitable habitats for caracals,which can be further proposed as survey areas and conservation priority areas for caracals.Conclusion:The study charts out the small pockets of landscape in and around dryland protected areas,suitable for caracal in the Indian context,which need attention for landscape conservation.展开更多
基金The National Key Technologies Research and Development Program of China under contract No.2013BAD13B00the Public Science and Technology Research Funds Project of Ocean under contract No.20155014the Shanghai Universities First-class Disciplines Project(Fisheries)
文摘In the Northwest Pacific Ocean, the squid jigging fisheries from China, Japan and other countries and regions have targeted the west winter-spring cohort of neon flying squid(Ommastrephes bartramii) from August to November since the 1970 s. This squid is a short-lived ecological opportunist with a life-span of about one year,and its population is labile and recruitment variability is driven by the environment or climate change. This variability provides a challenge for ones to forecast the key habitats affected by climate change. The catch data of O. bartramii from Chinese squid jigging fishery and the satellite-derived sea surface temperature(SST) data are used in the Northwest Pacific Ocean from August to November of 1998 to 2004, the SST preferences of O.bartramii corresponding to high values of catch per fishing day(CPUE) are determined and monthly potential habitats are predicted using a histogram analysis of the SST data. The possible changes in the potential habitats of O. bartramii in the Northwest Pacific Ocean are estimated under four climate change scenarios based on the Fourth Assessment Report(AR4) of the Intergovernmental Panel on Climate Change, i.e., 0.5, 1, 2 and 4°C increases in the SST because of the climate change. The results reveal an obvious poleward shift of the potential habitats of O. bartramii in the Northwest Pacific Ocean.
基金supported by the the Basic Frontier Project of Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences(E3500201)the Xinjiang Tianshan Talent Program(2022TSYCLJ0002)the Fundamental Research Funds for the Central Universities(ZY20240223).
文摘Understanding the spatial distribution of plant species and their dynamic changes in arid areas is crucial for addressing the challenges posed by climate change.Haloxylon ammodendron shelterbelts are essential for the protection of plant resources and the control of desertification in Central Asia.Thus far,the potential suitable habitats of H.ammodendron in Central Asia are still uncertain in the future under global climate change conditions.This study utilised the maximum entropy(MaxEnt)model to combine the current distribution data of H.ammodendron with its growth-related data to analyze the potential distribution pattern of H.ammodendron across Central Asia.The results show that there are suitable habitats of H.ammodendron in the Aralkum Desert,northern slopes of the Tianshan Mountains,and the upstream of the Tarim River and western edge of the Taklimakan Desert in the Tarim Basin under the current climate conditions.The period from 2021 to 2040 is projected to undergo significant changes in the suitable habitat area of H.ammodendron in Central Asia,with a projected 15.0% decrease in the unsuitable habitat area.Inland areas farther from the ocean,such as the Caspian Sea and Aralkum Desert,will continue to experience a decrease in the suitable habitats of H.ammodendron.Regions exhibiting frequent fluctuations in the habitat suitability levels are primarily found along the axis stretching from Astana to Kazakhskiy Melkosopochnik in Kazakhstan.These regions can transition into suitable habitats under varying climate conditions,requiring the implementation of appropriate human intervention measures to prevent desertification.Future climate conditions are expected to cause an eastward shift in the geometric centre of the potential suitable habitats of H.ammodendron,with the extent of this shift amplifying alongside more greenhouse gas emissions.This study can provide theoretical support for the spatial configuration of H.ammodendron shelterbelts and desertification control in Central Asia,emphasising the importance of proactive measures to adapt to climate change in the future.
文摘The general aim of this study is to find the relationship between the panda distribution and human activities. Comparison of the potential panda habitat and the real panda distribution shows a difference between them. Seven human activities were identified and analyzed. They are settlements, farming, road construction, firewood collection, timber production, mining and Chinese medicinal plant collection. The spatial distributions of these activities were characterized. The analysis of their spatial distributions and the pandas' habitat and distribution revealed that there is a relation existing between the human activities and the panda distribution, and the Giant Pandas have disappeared from the areas where the human activities are concentrated. GIS is the main tool used in this study to collect, store, retrieve, transform and present the spatial data of human activities and panda habitat and distribution in Wolong Nature Reserve.
文摘Background:Large-scale hunting and various anthropogenic pressures in the recent past have pushed the Asiatic caracal(Caracal caracal schmitzi),an elusive medium-sized and locally threatened felid species towards local extinction in India.Though widely distributed historically,it has been sparsely reported from several regions of central and northern states in India till twentieth century.Later,the species distribution became confined only to the states of Rajasthan,Gujarat and Madhya Pradesh,which have had reported sightings in the twenty-first century.In order to highlight the potentially suitable habitats for Asiatic caracals in India,we targeted forth-filtering of the spatial model ensemble by creating and utilizing the validated and spatially thinned species presence information(n=69)and related ecological variables(aridity,NDVI,precipitation seasonality,temperature seasonality,terrain ruggedness),filtered with anthropological variable(nightlight).Results:Out of eight spatial prediction models,the two most parsimonious models,Random Forest(AUC 0.91)and MaxEnt(AUC 0.89)were weighted and ensembled.The ensemble model indicated several clustered habitats,covering 1207.83 km^(2)areas in Kachchh(Gujarat),Aravalli mountains(Rajasthan),Malwa plateau(Rajasthan and Madhya Pradesh),and Bundelkhand region(Madhya Pradesh)as potentially suitable habitats for caracals.Output probabilities of pixels were further regressed with converted vegetation height data within selected highly potential habitats,i.e.,Ranthambore Kuno Landscape(RKL)(suitability~0.44+0.03(vegetation height)^(**),R^(2)=0.27).The regression model inferred a significant positive relation between vegetation height and habitat suitability,hence the lowest ordinal class out of three classes of converted vegetation height was masked out from the RKL,which yielded in an area of 567 km^(2) as potentially highly suitable habitats for caracals,which can be further proposed as survey areas and conservation priority areas for caracals.Conclusion:The study charts out the small pockets of landscape in and around dryland protected areas,suitable for caracal in the Indian context,which need attention for landscape conservation.