The role of shrub (Potentilla fruticosa) on ecosystem CO2 fluxes in an alpine shrub meadow

Recent studies have shown that alpine meadows on the Qinghai-Tibetan plateau act as significant CO 2 sinks. On the plateau, alpine shrub meadow is one of typical grassland ecosystems. The major alpine shrub on the plateau is Potentilla fruticosa L. (Rosaceae), which is distributed widely from 3 200 to 4 000 m. Shrub species play an important role on carbon sequestration in grassland ecosystems. In addition, alpine shrubs are sensitive to climate change such as global warming. Considering global warming, the biomass and productivity of P. fruticosa will increase on Qinghai-Tibetan Plateau. Thus, understanding the carbon dynamics in alpine shrub meadow and the role of shrubs around the upper distribution limit at present is essential to predict the change in carbon sequestration on the plateau. However, the role of shrubs on the carbon dynamics in alpine shrub meadow remains unclear. The objectives of the present study were to evaluate the magnitude of CO 2 exchange of P. fruticosa shrub patches around the upper distribution limit and to elucidate the role of P. fruticosa on ecosystem CO 2 fluxes in an alpine meadow.