| As the largest freshwater lake wetland in China,the Poyang Lake Wetland is also the largest migratory bird protection area in the world.Currently,research on migratory birds in the Poyang Lake Wetland mainly focuses on changes in the population structure of migratory birds,the landscape pattern of migratory bird habitat,and its influencing factors.In order to better understand the changing characteristics of typical migratory bird habitats in the Poyang Lake wetland in recent years,this study extracted the seasonal landscape types of the Poyang Lake during the high and low water periods in the past two decades based on RS and GIS technology,analyzed in more detail the interannual change characteristics of its landscape types,and explored the water inflow and outflow mechanisms and wetland landscape succession rules of the Poyang Lake.At the same time,quantitative analysis was conducted on the impact factors of typical migratory bird habitat in Poyang Lake wetland from the landscape scale,and the suitability of migratory bird habitat in 2000,2010,and 2020 was evaluated using the principles of landscape ecology.A wetland migratory bird habitat suitability evaluation model was constructed for typical migratory birds in Poyang Lake,and the change characteristics of wetland migratory bird habitat in the past 20 years were analyzed from multiple perspectives,and its driving mechanism was elaborated.Using the GAP analysis method and combining the current situation of the Poyang Lake Wetland Nature Reserve,the gaps in ecological protection of migratory birds in the Poyang Lake Wetland were explored,and specific strategies for protecting the habitat of migratory birds in the Poyang Lake Wetland were proposed through comprehensive consideration from various aspects.The main research contents and results are as follows:(1)The interpretation and classification of seasonal remote sensing images of Poyang Lake in2005,2010,2015,and 2020 show that;Generally,in March,Poyang Lake starts to be supplied by Ganjiang River,Xiuhe River,Xinjiang River,Raohe River,Fuhe River and other water sources.In September,the water of Poyang Lake flows out to the Yangtze River.The area of Poyang Lake area in the study area during the flood season is generally within the range of 1800～2100km~2,while the area of water patches in the dry season is as low as 532.66km~2,and the area of water body in the flood season of Poyang Lake in September 2020 has an abnormal value,that is,the highest is2704.07km~2.(2)Establish an evaluation model for habitat suitability of migratory birds in the Poyang Lake wetland,and analyze the current situation of habitat suitability of migratory birds in the study area in 2020;In 2020,the area of unsuitable habitat patches dominated the study area,with an area of8630.91km~2,accounting for 44.80%.The patch areas of less suitable habitats and general suitable habitats are relatively smaller,accounting for 28.93%and 18.81%of the total area of the study area,respectively.The suitable habitat patch area and the more suitable habitat patch area accounted for6.41%and 1.04%respectively.(3)Establish a migration habitat transfer matrix for migratory birds in the study area and analyze it;In the past 20 years,the suitable habitat for migratory birds in the Poyang Lake wetland has generally shown a degradation trend.From 2000 to 2010,19.19%and 36.63%of the general suitable habitat in the research area were degraded into unsuitable habitat and less suitable habitat,respectively.The degradation rate of the more suitable habitat was 53.15%,the transformation area reached 1264.36km~2,and the degradation rate of the suitable habitat was 49.79%.From 2010 to2020,the proportion of the unsuitable habitat increased slightly,and its wetland migratory bird habitat showed a certain degree of improvement.(4)Based on the principles of landscape ecology,the relevant landscape pattern indices in the study area were analyzed and obtained;suitable for habitat in 2010 The SHAPE＿AM value was 9.92higher than in 2000 and 2020,and the AI value of suitable habitats continued to rise.The patch area of suitable habitat for migratory birds in Poyang Lake Wetland has shown a downward trend over the past 20 years,and the concentration degree of its suitable habitat distribution has gradually increased.The SHDI value decreased from 1.38 in 2000 to 1.25 in 2010,and then increased to 1.26in 2020.The change rule of the SHEI value is consistent with that of SHDI.The various types of habitats of migratory birds in the Poyang Lake wetland are relatively evenly distributed in space.(5)Based on the GAP analysis of the existing nature reserve of Poyang Lake;In 2000,the sum of the suitable habitat areas for three species of migratory birds in the Poyang Lake National Nature Reserve was 234.94 km2,and the proportion of suitable habitats for migratory birds in each nature reserve reached over 90%.GAP analysis shows that there is a gap in ecological protection in the Poyang Lake region.Based on the current research situation,this paper proposes strategies for protecting migratory birds in the Poyang Lake wetland from five aspects. |
PDF Full Text Request