Abstract: [Objective] In order to reveal the ant distribution feature in southeastern Tibet, the ant distribution patterns in Galongla Mountains and Medog Valley were investigated. This study would provide a reference for biodiversity protection in the region. [Method] Sample-plot and searching methods were used to investigate distribution patterns of ant species in Galongla Mountains and Medog Valley. A sample-plot was set at every 250 m along the altitude. Within each selected sample-plot, five quadrats, each with 1 m×1 m, were set and the quadrat spacing was 10 m. In each quadrat, the ants from the land surface, soil and plants were investigated. After the sample-plot investigation, all places in the sample-plot were investigated by 5 people for one hour. [Result] A total of 20 371 ant individuals were collected from Galongla Mountains and Medog Valley, and belonged to 96 species, 45 genera, and 8 subfamilies of Formicidae. The subfamily of Myrmicinae was richest in genera and species (18 genera and 44 species involved) among the 8 subfamilies, followed by Ponerinae with 24 species in 10 genera. The subfamilies of Pseudomyrmecinae, Dorylinae and Leptanillinae each had only 1 genus and 1 species. The genus of Pheidole was richest in species (10 species involved) among the 45 genera. Most ant species from Galongla Mountains and Medog Valley distributed below the elevation of 2 000 m. Over the all species, Pheidole sagei had the widest range in vertical distribution, and the elevation difference was up to 1 510 m. Valley rainforest was richest in ant species among the 10 habitat types. The ant species nesting and forage on the ground were the richest among all types of nesting and forge sites. In addition, some species could also forge on the tree. Moreover, 95 ant species distributed in south slope and only 5 species distributed in north slope. Myrmica bactriana occupied the widest range of habitats, nesting and forage sites.[Conclusion] The distribution of ant species in Galongla Mountains and Medog Vally is restricted by altitude and plant richness. At the same time, distribution patterns of ant species are affected by slope aspect. As for nesting and forging sites choice, ants firstly ensure the nest relatively dry and the plentiful source of food. Thus ants choose different habitat and foraging and nesting sites, which would avoid the intraspecific and interspecific competition and be in favor of the establishment and development of ant colony.

Key words: Formicidae, ants, vertical distribution, habitat splitting, Southeastern Tibet