Spatiotemporal Changes in Waterfowl Habitat Suitability in the Caohai Lake Wetland and Responses to Human Activities

The Caohai Lake wetland is one of the most important wetlands in China and is also one of the most important overwintering areas for waterfowl. However, the spatiotemporal changes in the waterfowl habitat’s suitability and its response patterns to human activities are still unclear. Understanding these patterns is key to plateau wetland biodiversity conservation. In this study, remote sensing, the geographic information system, and global positioning system (3S) technology were employed, and the water source status, disturbance, shelter, and food availability were used as evaluation factors for waterfowl habitat selection. A suitability evaluation model was constructed to evaluate the spatiotemporal characteristics of the Caohai Lake wetland habitat’s suitability in 2000, 2010, and 2022, and to evaluate the response mechanisms of the waterfowl toward human activities. The results show the following: (1) there were frequent changes in the suitability grade of the study area from 2000 to 2022, and there was an overall trend toward improvement as the areas of suitable regions continuously increased. This was due to the continuous improvements in water source status, food availability, and shelter. (2) Human disturbances gradually increased from 2000 to 2022, and the human disturbance index was negatively correlated with the waterfowl habitat suitability. (3) There were significant spatial differences in the suitable waterfowl habitats. The marshlands near the banks of the lake were the regions with optimum and good suitability, while the areas of poor suitability and unsuitable regions were the deep-water areas, roads, and residential areas with high human disturbance, along with the regions near these areas. It is vital to further decrease human disturbances, in order to increase the habitat suitability of the study area.