Responses of reproduction and important value of dominant plant species in different plant functional type in Kobresia meadow to temperature increase

Abstract

Responses of reproduction and IV (important value) of dominant plant species in different PFT to warming were studied at a Kobresia meadow in the Tibetan Autonomous State of Qinghai Province, China (37A degrees 29'aEuro"37A degrees 45' N, 101A degrees 12'aEuro"101A degrees 33' E, 3900 m asl) using the temperature gradient method formalized by the ITEX. Responses of Elymus nutans and Poa pratensis (Gramineous PFT) to increasing temperature were similar. The numbers of tillers, buds and IV increased in the chambers treated with higher temperature compared to the control without treatments (CK). Responses of Kobresia humilis and Carex alrofusca (Cyperaceae PFT) to increasing temperature were different, that is, the numbers of tillers and IV reached the maximum in different temperature among species, the numbers of buds decreased with the temperature increasing. The number of buds and IV of Lagotis brachystachya (Forbs PFT) decreased with the warming, but the number of stolons was initially large, and then decreased with increasing temperature. The number of buds of Ranunculus brotherusii (Forbs PFT) increased with the temperature increasing in the first year, but decreased in the second year; and IV decreased with the temperature warming. Under conditions of continued warming in the future, PFT structure will be significantly changed, Cyperaceae PFT dominant plant species original position will be replaced by Gramineae PFT dominant plant species. Cyperaceae plants will become the dominant species, and some species belonging to Forbs PFT will be eliminated from the community.