Recent changes of climate and livestock productions on the Tibetan Plateau and in situ observations of NEE

Abstract

Grassland occupies about 50% of the Tibetan Plateau and acts as a carbon sink nowadays. Climate warming may increase the productivity of the grassland and may also accelerate carbon releasing at the same time, especially when grassland degradation occurs. We have been measured the CO₂ flux at a wide-distributed alpine meadow since 2001 and at a wide-distributed alpine wetland since 2009 by eddy covariance (EC) method on the Tibetan Plateau. Recent climatic change and change of livestock production in relation with in situ observation of grassland net ecosystem CO₂ exchange (NEE) are analyzed. We find that livestock production increased more greatly in recent years although the climate warming is not so clear as before and in situ NEE observation does not show any increase trend. It is suggested that the expansion of artificial grassland plays a critical role in promoting livestock production in recent years due to there is very good linear relationship between the increased amount of meat production and annual production of fodder after 2001 in Xizang.