The study of species and phylogenetic diversity on karst forest along Lijiang River

Abstract Forest community is the key point of global biodiversity conservation for its large number of species. Over the centuries, many scholars have tried to reveal the community diversity of forests such as tropical rainforests. But we know very little about karst forests because it is distributed in very few areas of the world. Lijiang river basin, a subtropical karst forest area, is a vital biodiversity hotspot in South China. In this paper, we aimed to reveal the characteristics of forestry species diversity in the karst area of Lijiang River by Hill diversity and two beta diversity partitioning method. We also studied the phylogenetic diversity and established a pedigree tree for the karst forest in the whole basin. Our findings showed that alpha diversity and beta diversity was quite different between the watershed. The alpha diversity indices in the upper reaches were significantly higher than that of the rest reaches, while the beta diversity was extreme variation among planted forest than natural forest. The decomposition of beta diversity in these karst forests showed that the diffusion limitation was the main driving force causing the beta diversity difference. The phylogenetic structure showed that the midstream karst forest had more distantly related species than other basins. We found that upstream forest was under species invasion while midstream karst forest was under factitious threatened. We suggest that the karst forests in the Lijiang River basin should be protected immediately. This study also filled the gap in the study of karst forests in subtropical regions.