Zonation-based prioritization of vegetation conservation for terminal lakes in drylands

Abstract

Terminal lakes are imperative to regulate regional climate and construct an ecological barrier in drylands. In recent decades, many terminal lakes have shrinked sharply and undergo seriously ecosystems degradation because of climate change and human activities. In order to restore the decline of the world's terminal lakes, various restoration programs, such as ecological water transfer, have been implemented worldwide to increase the area of the terminal lake while ignore restore the vegetation around the lake, especially the priority restored location, area and vegetation types. We used Zonation to generate a framework to identify the vegetation conservation priority sequence of the terminal lake in drylands based on the remote sensing dataset. And then taking the Taitema Lake, Northwest China, as a study area, analyzed the vegetation conservation priority sequence of Taitema Lake. We found that the vegetation of Taitema Lake is mainly perennial herbs, whose distribution area accounts for 57.7% of the total vegetation area, shrubs for 39.6%, and annual herbs for the least, 2.7%. The high-priority areas for vegetation protection are mainly distributed in the lacustrine plain area of Taitema Lake, where the high-priority areas for vegetation protection of perennial herbs and annual herbs are distributed in the lacustrine plain at the end of Qarqan River, and the high-priority areas for vegetation protection of shrubs are distributed in the lacustrine plain at the end of Tarim River. In each priority area, the area of perennial herbs is between 50 and 60%, shrubs are between 30 and 45%, and annual herbs are between 0%–11%. The framework developed in this study can effectively determine the conservation priority location, area and types of vegetation around the terminal lakes in drylands with easily available dataset like NDVI, and provide a basis for the precise conservation of vegetation around the terminal lake.