RESUMO
As a wetland of international importance, the ecological function zone of the Sanjiang Plain (EFZSP) plays an important role in maintaining waterfowl habitat. With the increasing disturbance of human beings, land use and climate changes, habitat suitability for waterfowls (HSW) has drawn greater attention of ecologists. In this study, Landsat TM/ETM+/OLI and HJ-1B images in 1990, 2000, 2010 and 2015 were used to obtain land cover classification by object-based image analysis, and the entropy and analytic hierarchy process methods were adopted to determine the factors and their weights, the factors selected in this study included water condition (lake and river density), disturbance factor (residence and road density), shelter condition (land cover type and slope), and food abundance (NDVI). Finally, the evaluation results of habitat suitability of year 1990, 2000, 2010, and 2015 were achieved based on the habitat suitability index (HSI) system, and the spatio-temporal dynamics and driving forces causing the changes were analyzed. The results showed that the excellent level of HSW mainly distributed in abundant water areas, especially along the riparian zone of the Heilongjiang River, Naoli River, Ussuri River, Muling River and Xingkai Lake. Its area decreased by 3.2% from 1990 to 2015 because of wetland reclamation. The good level of HSW concentrated in Raohe County over the past 25 years, the condition of Hulin County and Fuyuan County were improved to a good level from 2010 to 2015 due to the substantial increase of paddy field areas. The fair level of HSW distributed dispersedly, and the areas first increased from 1990 to 2000 and then decreased during 2000-2010 and 2010-2015 periods. The areas of poor le-vel increased by 6.7% from 1990 to 2000 and decreased by 3.1% from 2000 to 2015. The change of HSW level in this study area was dominated by land cover change, and both of the increasing population and economy and the drying and worming climate resulted in the decline of the HSW level, whereas the establishment of nature reserves is crucial to protect habitat for waterfowls.