Abstract:

To determine the appropriate plot size for estimating plant diversity of different types of alpine grassland on the Qinghai-Tibetan Plateau (QTP), i.e. alpine meadow, alpine steppe and alpine desert, seven models were applied in the examination of species-area relationships. Depending on the optimal species-area relationship curves, the minimum sizes of sampling plot for each type of grassland under healthy and degraded conditions were obtained. The findings were as follows: (1) Non-saturation curve models were most suitable for describing species-area relationships of alpine grasslands on the QTP; (2) For all three types of alpine grassland, the minimum plot size for healthy grasslands was larger than that for degraded ones; (3) Minimum plot sizes for estimating plant diversity were 108 m² and 82 m², respectively, for healthy and degraded alpine meadow, 130 m² and 81 m², respectively, for healthy and degraded alpine steppe, and 60 m² and 41 m², respectively, for healthy and degraded alpine desert.

Key words: Qinghai-Tibetan Plateau, alpine grasslands, species-area relationship, minimum plot size