© 2018 by the authors. Carbon-use efficiency (CUE) is the proportion of gross primary production converted to net primary production. Changes to CUE strongly influence ecosystem carbon budgets and turnover. Little is known about the response of ecosystem CUE to human-induced land-use change, which limits the accurate evaluation of the environmental influence of large-scale steppe-use changes in northern China. We investigated the components of ecosystem carbon exchange and CUE under three typical steppe-use patterns in Xilinhot, Inner Mongolia. The results showed that CUE in grazing and grazing-excluded steppe were not significantly different (both over 0.7) but were significantly higher than in cultivated steppe (0.57). Ecosystem respiration and its components, including autotrophic respiration (Ra), aboveground respiration, heterotrophic respiration and belowground respiration showed significant negative correlation with CUE. Ra is the most important factor explaining the variation of CUE between different steppe-use patterns (p < 0.001, 97%); Ra change may be the primary factor driving CUE variation between steppe-use patterns. Leaf area index of diff erent grassland-use patterns also showed a significant negative correlation with CUE (p < 0.001, 91%). These findings may help to improve accurate prediction of the environmental and climatic consequences of large-scale land-use change.
Li, Y., Fan, J., & Hu, Z. (2018). Comparison of carbon-use efficiency among different land-use patterns of the temperate steppe in the northern China pastoral farming ecotone. Sustainability (Switzerland), 10(2). https://doi.org/10.3390/su10020487