Spatial patterns of vegetation carbon sinks and sources under water constraint in Central Asia

Abstract

The terrestrial ecosystem carbon cycle is a major contributing factor in the rise in global average temperature. Based on the net ecosystem production (NEP) calculation model and classifications, the spatial distribution patterns of carbon sources and sinks for vegetation in Central Asia are analyzed. The results show obvious zonal characteristics in the distribution of carbon sources and sinks. Carbon source areas form the majority and are mainly located in south-central Kazakhstan and parts of Uzbekistan and Turkmenistan, while most carbon sink areas are located in northern Kazakhstan, Kyrghyzstan and Tajikistan. NEP shows a downward trend during 2000–2015, indicating decreasing capacities of low and high carbon sinks in forest land, sparse vegetation, and bare areas. Even a weakening in the carbon sink capacity resulted in no significant decrease, indicating instead a decline in grassland quality. The change in NEP matches the change in terrestrial net primary productivity (NPP). Water is the limiting factor for ecological attributes in arid and semi-arid areas, with drought influencing both the carbon budget and balance. These conclusions are critical for maintaining ecological stability and sustainable economic development in the Silk Road Economic Belt.