Plant Diversity and Black-Necked CraneDistribution in Caohai Wetland, Southwestern China

The Caohai Wetland is an important habitat for many rare birds, such as black-necked cranes. This study focused on the species composition and diversity of plants in the seven main habitats of black-necked cranes in the CaohaiWetland, and on the distribution characteristics of black-necked cranes in these habitats in the winter season from November in 2022 to March in 2023. A total of 138 species belonging to 111 genera, 40 families, 23 orders and 4 classes and 2 phyla were recorded during field investigations involving 31 investigated plots, which comprised 112 quadrats. Among the different investigated plots in the seven habitats ofblack-necked cranes, the Shannon-Wienerindex values ranged from 0.1125 to 2.4800. Notably, plant species diversity decreased in almost all habitats from the terrestrial zone to the water-land transitional zone and from the water-land transitional zone to the shallow water zone. The water level, habitat area, microcirculation heterogeneity and grazing activitiesare critical factors related to plant species diversity. In this winter, about 2,469 black-necked cranes overwintered in the seven main habitats. Black-necked cranes inhabiting in Huyelin (HYL) and Wenjiatun (WJT) are of absolute advantage in terms of population among the seven major habitats. To better protect the habitat of black necked cranes, we need to control the spread of tall plants, scientifically regulate the plant community structure of the habitat in combining with black necked crane feeding habits, and to regulate the water level of Caohai Lake reasonably to ensure sufficient water-land transitional zone and shallow water zone for black-necked cranes to inhabit.