The Vegetation Dynamics and Climate Change Responses by Leaf Area Index in the Mu Us Desert

Abstract

Knowing the long-dated dynamic changes of vegetation in the Mu Us Desert is critical for strengthening sustainable management of vegetation restoration projects in the next planned cycle until 2050. To predict leaf area indexes (LAIs) under long-dated climate scenarios (2013–2050) in the Mu Us Desert, the relationship between earlier meteorological data and LAI was tracked with regression analysis on the basis of LAI data from the Global Land Surface Satellite (GLASS) and the grid meteorological data during 1982–2012, and the LAIs were estimated based on five-Global Circulation Model (GCM) ensemble means under three representative concentration pathways (RCP 2.6, RCP 4.5 and RCP 8.5). We found an increasing trend in precipitation and a significant increase in potential evapotranspiration (PET) during the earlier period in the Mu Us Desert, and that could continue into the long-dated under three RCPs in the Mu Us Desert. Warming trends occur in the earlier and long-dated periods for annual average air temperature. Compared with the observations, the temperature rises respectively by 0.6 ℃, 0.7 ℃, and 1 ℃ under the three RCPs mentioned above. The annual maximum LAI largely increased with a rate-of-change of 0.029 m2·m−2·yr-1. Precipitation has been a major influencing factor to vegetation dynamics and growth in the Mu Us Desert. The permissible LAIs by 2050 are 0.42–0.88 m2·m−2, 0.42–0.87 m2·m−2, and 0.41–0.87 m2·m−2 under the three RCPs, respectively. Contrasted with the baseline period (1982–2012), the LAI is found to be already close to the current value in the northwestern and southern Mu Us Desert.