Avian Diversity Comparison in Karst Farming Area of Southeastern Yunnan

The growth of cultivated land is thought to be a major factor in the ecosystem's degradation and biodiversity loss in the karst mountainous regions of southwest China. To investigate the impact of avian diversity in various agricultural habitats in the karst areas, we conducted bird surveys using the line transect method in Maguan County, Yunnan Province, between January 2017 and March 2018. There were 66 transcects set up in all. The habitats of the transects were divided into 4 types according to the intensity of agriculture: control plot woodland, low-intensity agriculture, medium-intensity agriculture, and high-intensity agriculture. The results were as follows: a total of 255 bird species were recorded, including 156 species in woodland, 167 species in low-intensity agriculture, 179 species in medium-intensity agriculture, and 120 species in high-intensity agriculture. During the breeding season, the species richness, functional diversity and phylogenetic diversity of birds differed significantly among habitats, with the highest levels found in the medium-intensity agriculture. In the non-breeding season, there was no significant difference in the diversity index of different habitats. Correlation matrix analysis showed that there were seasonal differences in habitat preferences of bird feeding communities. From this, the impact of agricultural intensity on bird diversity during the breeding season showed more pronounced than during the non-breeding season. The medium-intensity habitat had higher bird diversity and complex functional groups. Bird diversity in woodlands is low, but these areas provide essential shelter for some species. Thus, it's crucial to enhance forest protection in karst areas and prevent the conversion of mixed agroforestry habitats to high-intensity agricultural land.