Studies On The Identification And Landscape Pattern Changes Of Important Stopover Sites Of Siberian Cranes

Siberian crane(Grus leucogeranus)is listed as the national first class protected wild animal and a flagship species of wetland conservation and listed as a "critically endangered" species on the International Union for Conservation of Nature(IUCN).Siberian crane is also the flagship species of wetland ecosystem protection.It needs to cross many important stopover sites on the migration route.The landscape structure of the habitat plays an extremely important role in the migration and stop of Siberian crane.With the intensification of human activities in recent years and the influence of many factors such as climate change,the landscape of Siberian crane wetland has changed drastically,the integrity of the wetland has been reduced,and the ecological function of the wetland has been destroyed,which has seriously threatened the number and distribution of Siberian crane in the wetland.Protection is imminent.Therefore,we need to focus on controlling the interference of human activities on wetlands by improving the land use pattern,which is of great significance to the protection of local species such as Siberian crane and the ecological diversity of the wetlands on which they depend.This study used the positioning data of 21 satellites tracking Siberian crane from 2014 to2020 to identify and classify all the stopover sites during the tracking of Siberian crane.At the same time,the method of supervision and classification was used to interpret the remote sensing images of Chinese Siberian crane’s important stopover sites in 2015 and 2020 respectively,and the land use information of each time phase was obtained and quantitatively described and analyzed the land of Chinese Siberian crane’s important stopover sites Changes in utilization/cover types and evolution of landscape patterns provide a scientific management basis for comprehensive and effective protection of Siberian crane habitat.The main research conclusions are as follows:(1)Based on the satellite tracking of 13 Siberian cranes with complete migration routes,a total of 187 stopover sites were identified,including 11 important stopover sites abroad and 14 important stopover sites in China.This study found for the first time six important stopover sites for Siberian cranes in China,namely the Lena River,Kytalyk Nature Reserve,Ygannya River,Suturuokha Lake,Uyandina River,Argaka Lake,Selennyakh Lake,Balyma Lake,Iindigirka River,Badyarikha River and Serediska Lake.There are 14 important stopover sites in China,among which 10 are the important stopover sites in Northeast China.There are 6important stopover sites for Siberian crane in China discovered for the first time: Lianhuan Lake of Durbert Mongolian Autonomous County,Heilongjiang Province,Zhurihennaur Lake of Horqin Right Wing Middle Banner and Wulanwusu Reservoir of Aohan County,Inner Mongolia Autonomous Region,Shijiu Lake at the junction of Anhui and Jiangsu Provinces,middle reaches of Pihe River of Luan City,Anhui Province,and Qishui of Qichun County,Hubei Province.(2)From 2015 to 2020,the land use of the important stopover sites for Siberian crane in China has changed significantly,and the landscape types with large changes in the area ratio are cultivated land and grassland.Cultivated land is the land category with the most growth.Among them,the rest areas with more cultivated land growth include Wolong Lake Reserve,Huanzidong Wetland Park and Wulanwusu Reservoir.Only the area of cultivated land in the Tumuji Nature Reserve,Hulesitainor Wetland Park and Agula Wetland Park decreased slightly,and the area was basically the same as in previous years,and the overall arable land showed an increasing trend.Grassland is the land category with the most reduction.Among them,the resting places with more grassland reduction are Huanzidong Wetland Park,Wolong Lake Nature Reserve,the middle reaches of Pihe River,Wulanwusu Reservoir,Shijiu Lake,and Qishui.The largest increase is in the Tumuji Nature Reserve,and the overall grassland shows a decreasing trend.The area of the water area has decreased overall,among which the area of lakes has decreased,while the area of rivers,mudflat and reservoir ponds have increased slightly.In short,the habitat suitable for Siberian crane has decreased.(3)From 2015 to 2020,the various land use types of the important stopover sites of the Siberian crane in China have transferred to each other,and to varying degrees.The transfer of grassland,lakes,construction land,and forest land is greater than the new increase,and the new increase of cultivated land,rivers,reservoir ponds,unused land and mudflat is greater than the transfer.Among them,the main transfer types of grassland are cultivated land and unused land,the main transfer types of cultivated land is grassland,and the main transfer types of lakes are cultivated land,grassland and unused land.This indicates that part of the Siberian crane habitat has been converted into cultivated land and unused land,and there is a trend of reduced habitat area and deterioration of habitat quality.(4)From the perspective of the patch type level index,the study area has shown a trend of fragmentation as a whole during 2015-2020,especially the fragmentation of natural landscape patches is obvious.From the perspective of the landscape index of these two periods,the grassland The area proportion(PLAND)of the whole patch type of natural wetland decreased,the number of patches(NP)and patch density(PD)increased,and the maximum patch index(LPI)decreased,while the overall patches of non-wetland landscapes such as cultivated land and construction land The type area(PLAND)increases,the number of plaques(NP)and plaque density(PD)decrease,and the maximum plaque index(LPI)increases.This shows that the types of wetland landscapes in the study area tend to decrease,and the wetland landscapes are transformed into non-wetland landscapes.Non-wetland landscapes have gradually become the dominant landscapes in the study area,and wetland habitats are increasingly lacking.From the perspective of the overall landscape level index,the concentration index in the study area has shown an upward trend during the five-year period,while the diversity index and evenness index have shown a downward trend.The landscape pattern of the study area generally develops in the direction of high agglomeration,low uniformity,and reduced landscape diversity,indicating that the distribution ratio of the area of each landscape type is unbalanced,and the landscape pattern is developing in the direction of simplification.