Preliminary Survey On Cave Biodiversity In Du'an Karst Of Northern Guangxi

In Du'an Yao Autonomous County(Northern Guangxi), karstic lands cover 3, 863 km2, about 94% of the total area. Du'an Karst holds numerous cave-dwelling animals. The paper is a preliminary result of cave biodiversity surveys in Du'an Karst carried out in recent years, with the main points as follows.1. In total, 65 limestone caves were surveyed in Du'an Karst since 2013, with collecting of 1550 cave-dwelling animal specimens. Up to date, 102 species(or morphological species) were identified, belonging to 56 genera, 46 families, 30 orders, 13 classes and 5 phyla. Among them, 76 and 36 species were Arthropoda(about 74.51 % of all the cave animals) and Insecta(about 47.31% of Arthropoda), respectively. The dominant groups were woodlices(5 species in 3 genera and 3 families), millipedes(15 species in 5 genera, 5 families and 3 orders), ground beetles(19 species in 7 genus and 4 tribes), cave fishes(9 species in 5 genus and 3 familes), springtails(5 species in 3 genus and 3 families) and cave crickets(several sepcies in genus Diestrammena). Other animals occasionally seen in cave were frogs(4 species in 3 genera and 2 families), pseudoscorpions(2 species in 2 genera and 2 families), cockroaches, bugs and so on. Blind fishes and blind beetles belonging to trechini were renowned as the flagship species in aquatic and terrestrial habitats respectively. There were 32 common cave species of vascular plants in Du'an Karst, belonging to 26 genera and 22 families.2. Cave biodiversity is comparatively rich in Du'ankarst area. In particular, 15 species of blind trechine beetles have been discovered from the limited area, accounting for 13.51% of all known species in China, or 42.86% of all known species in Guangxi. While, 9 species of typical cave fishes were recorded in Du'an Karst, as more as 9.0% and 14.52% of the total recorded species in China and Guangxi respectively. Among cave fishes, 3 species were completely blind speies, as 7.89% and 14.29% for China and Guangxi respectively. In addition, millipedes and woodlices were also very rich in Du'an Karst.3. Endemism of cave animals is very high in Du'an Karst. Cave is a relatively isolated and fragile ecosystem, all troglobetic animals in Du'an Karst were narrowly distributed, with the endemism is as high as 100%. Therefore, all of them are worth to be protected by law.However, this work is only a start regarding to the numerous cave resources in Du'an Karst. It is expected that more and more cave animals will be discovered in Du'an within near future.