Abstract:

Aims β diversity reflects species turnover rate across environmental gradients, and this study attempts to use β diversity to reveal relevant ecological processes underlying the changes in plant community composition along a disturbance gradient induced by small burrowing herbivores.
Methods This study conducted a field survey at Gangcha County in the Qingzang Plateau to determine the effect of disturbance intensities of plateau pika (Ochotona curzoniae) on the β diversity of an alpine meadow measured by Whittaker’s index. Then a variance decomposition was used to measure the contribution of individual species to overall β diversity (SCBD) and single interference sites to overall β diversity (LCBD) according presence- absence community matrix.
Important findings The turnover rate of species in the plant community first increased and then decreased with the increase of the disturbance intensities induced by plateau pika. Species with intermediate site occupancy had a greater contribution to β diversity, in which Agropyron cristatum, Artemisia hedinii and Anemone rivular var. flore-minore were the single-species plants that contributed the most to the β diversity of the study regions. The disturbance plot T₀ with the absence of plateau pika had the greatest contribution to the β diversity of whole study region. LCBD of individual site was negetively related to species richness of that individual site, and had no significant correlation with the disturbed intensity of plateau pika. These results indicate that alpine meadows distributed in high LCBD and Agropyron cristatum, Artemisia hedinii and Anemone rivularis var. flore-minore with high SCBD should be protected to conserve plant diversity when the plateau pikas are present.

Key words: plateau pika, alpine meadow, β diversity, disturbance, correlation