Effects Of The Expansion Of Phragmites Australis On The Wintering Behavior Of Black-necked Cranes (Grus Nigricollis) In Caohai Nature Reserve, Guizhou Provinc

The Black-necked Crane(Grus nigricollis)is the last of 15 species of the family,The only migratory birds that grow and breed on the plateau.Guizhou Caohai Wetland is one of the most important wintering grounds for the eastern population of Black-necked Cranes,About 2,000 Black-necked Cranes overwinter in the Caohai every year,Moved to Caohai Wetland at the end of October,moved away from Caohai at the end of the next March.The quality of wintering habitats influenced their life history throughout the overwintering period.In recent years.Caohai wetland marsh standing water plant reed(Phragmites australis)from the north bank-southeast-south rapid expansion spread,Forcing the reduction,fragmentation and discontinuity of the Black-necked Crane wintering habitat.In order to find out the impact of reed expansion and spread on the overwintering habitat selection and utilization of black-necked cranes?This study included reed and black-necked cranes in Caohai National Nature Reserve.The spatial pattern analysis of the grass-shore zone,reed community and black-necked crane habitat type by fixed-point observation,sample method and spatial pattern analysis,Exploring the influence of reed expansion on the behavioral activity of black-necked crane population variation and habitat type selection from the perspective of landscape ecology principles,The study results are presented as follows.1.The expansion area of reed plants in the lakeside zone of Caohai wetland shows an increasing trend,By 2022,the total area of reed expansion is about 429.10 hectares.Reed communities continued to spread from north to south,Two night habitats of Liujiaxiang and Zhujiawan in the south are affected by reed invasion,Resulting in a biased selection of habitat and foraging sites in black-necked cranes.2.The population of black-necked cranes in Caohai Wetland over the years,Growing from 35 in 1975 to 2,898 in 2023,After several vicissitudes of life,the population of black-necked cranes grows rapidly,and the population size is getting larger and larger.This indicates that the influence of reed expansion on the population number of black-necked cranes has not reached a certain threshold.3.The continuous expansion of reeds squeezes the living space of rare wintering birds such as black-necked cranes,The selection of night habitat of black-necked cranes shifted southward,and the area gradually shrinks,There are even new choices of the surrounding marshes as a night habitat.4.The area of outdoor foraging ground of black-necked cranes has gradually increased,And to the northwest direction of the farming area outward expansion,Foraging sites are farther away from the habitat than usual.5.Control mode of the reed:By comparing the three reed control methods of artificial ploughing,flooding and cutting,The preferred plant plants,such as hydroonion,watskiva,hydrosedge,and rushes,had the best results.