04.14.2020

Quantitative analysis of the contributions of land use change and CO2 fertilization to carbon use efficiency on the Tibetan Plateau

Xin Luo, Binghao Jia and Xin Lai

Highlights

  • The contributions of climate factors, CO2 fertilization and land use change to CUE on the TP are quantitatively examined.
  • LULCC shows higher positive contributions to annual mean CUE than CO2 fertilization on the TP.
  • Precipitation and temperature have positive correlations with CUE, while solar radiation has a negative correlation.

Abstract

Carbon use efficiency (CUE) is a key element in the vegetation carbon cycle, and determines how vegetation allocates carbon. Here, our research provides the spatio-temporal variations of CUE on the Tibetan Plateau (TP) based on ensemble simulations from 12 terrestrial ecosystem models. Moreover, the experimental design of simulations adds one time-varying driver at a time, thus quantitative analysis of the response of CUE to climate factors (i.e., temperature, precipitation and radiation), land use and land cover change (LULCC), and CO2 fertilization can be investigated. Results show that average CUE value of the multi-model simulations (0.583 ± 0.064) on the TP is slightly lower than that derived from the satellite-based product, the Moderate Resolution Imaging Spectroradiometer (0.646). However, CUE varies greatly among models due to differences in simulating plant photosynthetic productivity and respiratory rate, with range of 0.489–0.661. LULCC and CO2 fertilization contribute 4.24% and 0.79% of the annual mean CUE, respectively. Among the climatic factors, temperature and precipitation have positive correlations with CUE over most areas of the TP while solar radiation shows a negative impact.

The full article appeared on the Science of the Total Environment website at https://www.sciencedirect.com/science/article/pii/S0048969720321239]]>

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