基于Sentinel-2A影像的杭州湾南岸湿地植被特征及其候鸟生境分析

互花米草的入侵与扩张占据了其他植物的生态位，在一定程度上，改变甚至破坏了滩涂景观，对原生生态系统造成了消极影响。利用2019-2021年Sentinel-2A影像，结合最大似然分类法与决策树分类法对杭州湾南岸互花米草等多种生境类型加以识别，并进一步讨论生境变迁对迁徙候鸟的影响。结果表明：（1）决策树分类法总体精度更高且细节信息更为丰富，但存在较为明显的漏分现象；（2） 2019-2021年互花米草分布范围不断扩大且空间分布愈发离散，严重侵占芦苇、光滩等生境的生态位，导致总体生境景观趋于破碎；（3）受互花米草入侵的影响，适宜鸻鹬类候鸟栖息的光滩与海三棱藨草生境面积锐减，整体生境状况愈发复杂多样，候鸟适宜生境面积呈明显减少趋势。

Vegetation characteristics and habitat analysis of migratory birds in southern Hangzhou Bay wetland based on Sentinel-2A imagery

The invasion and expansion of Spartina alterniflora occupied the niche of other plants, changed or even destroyed the beach landscape to a certain extent, and had a negative impact on the original ecosystem. Based on Sentinel-2A images from 2019 to 2021, we combine maximum likelihood classification and decision tree classification to identify a variety of habitat types, including Sparta alterniflora, along the southern coast of Hangzhou Bay, and the effects of habitat changes on migratory birds are further discussed. The results show that: (1) The overall accuracy of decision tree classification is higher and the details are more abundant, but there are obvious omissions. (2) From 2019 to 2021, Spartina alterniflora continues to expand and its spatial distribution becomes more and more discrete which seriously encroach on the niche of Phragmites australis, bare beach and other habitats, resulting in the overall habitat landscape tends to be broken. (3) Under the influence of the invasion of Spartina alterniflora, the habitat area of bare beach and Scirpus mariqueter which are suitable for migratory birds decreases sharply, the overall habitat becomes more complex and diverse, and the suitable habitat area of migratory birds decreases obviously.