Biodiversity conservation and management of lake wetlands based on the spatiotemporal evolution patterns of crane habitats

Abstract

The typical lake wetlands in the middle and lower reaches of the Yangtze River are important wintering sites of cranes in China. The spatiotemporal evolution of crane populations and their habitats has great value in clarifying the pivotal role of regional lake wetlands in biodiversity conservation. Therefore, 2562 data points of four crane species were selected in this study. The data reflected the distributional position of the cranes over the period 2000-2020. Twelve surrounding environmental factors were selected to investigate the spatiotemporal evolution in the study area by using the MaxEnt model. The Jackknife method was used to identify the main environmental factors affecting the choice of crane habitats. The results indicated that: (1) Developed land in the study area increased by 42,795.81 hm². The crane populations were mainly distributed in the farmland and mudflat, and their number decreased yearly. (2) From 2000 to 2020, the area of suitable crane habitat experienced an overall decrease. Specifically, the mid-suitable area dwindled by 6234.23 hm², marking a substantial reduction of 52.05 %. Similarly, the most suitable area saw a decline of 786.41 hm², representing a noteworthy decrease of 71.09 %. (3) The findings from the analysis of influencing factors revealed a dynamic pattern over the years. Habitat type, water density, and distance to water were the main influencing factors in the study area from 2000 to 2020. This study provides a new perspective on the conservation and structural habitat restoration of crane populations in the middle and lower reaches of the Yangtze River.

Keywords: Crane habitats; Lake wetlands; MaxEnt model; Spatiotemporal evolution.