Patterns of plant diversity at high altitudes on the Qinghai-Tibetan Plateau

Aims To describe the biodiversity patterns of plants along an altitudinal gradient oil the Quighai-Tibetan Plateau and to clarify file bias in plant specimen records at high altitude Methods We conducted a large-scale investigation of vegetation at a wide range of altitudes, focusing oil a high-altitudinal range (3 200-5 200 m) at different locations on the Qinghai-Tibetan Plateau We then compared the altitudinal distribution of plant species obtained from our field investigation with that in plant specimen records from published sources and an online database Important Findings Our data provide evidence that altitude plays a large role in regulating species composition on the Qinghai-Tibetan Plateau WC Could not, however, detect a clear relationship between altitude and spe cies richness, although a weak monotonically increasing trend of richness was detected with increasing altitude According to specimen records, most species have been sampled at a wide range of altitudes, and the average range of 145 species is >2 000 m Despite this wide range, more than half of the species we observed were at higher altitudes than the specimen records indicate High-altitude areas have probably been so poorly sampled that Only a small fraction of the resident species has been recorded This' Study clearly shows the regional bias of specimen records in the Qinghai-Tibetan Plateau