LAUSR

Abstract The ecosystems of Mongolia are among the most sensitive to global climate change because they are located in the circumpolar boreal zone, with its arid and semiarid climate. This study used the Carnegie-Ames-Stanford Approach (CASA) model parameterized by meteorological and remote-sensing data to quantify vegetation net primary productivity (NPP) for Mongolia for 1982–2011 and further constructed a map of the relative contributions of climatic constraints to NPP. The results showed that 30-year average NPP in Mongolia varied spatially from 18.1 to 662.8 g C/m2, with an average of 228.2 g C/m2. From the map of climatic constraints on NPP, it was estimated that temperature constrains NPP variation over about 3.9% of Mongolia's land area, whereas precipitation constraints are dominant over about 77.5%. NPP in temperature-constrained regions has continuously increased from 1982 to 2011, with an annual increment of 2.18 g C/m2 (R = 0.61, p