Reply to Wang et al.: Uncertainty of terrestrial ecosystem CO_2 exchange of the Tibetan Plateau

摘要

We welcome the letter from Wang et al. (1) regarding the uncertainty in eddy covariance (EC) measurements on the Tibetan Plateau (TP) and appreciate the opportunity to clarify our thinking. Our study focuses on the CO_2 exchange between the air and plants/soil on the TP (2), rather than the carbon (C) balance of the whole region; for instance, we did not measure the C sources/sinks in water bodies (3). Furthermore, different approaches tend to yield inconsistent results regarding the CO_2 sink of a region-for example, in the Arctic (4, 5). Our estimate, based upon 32 EC towers, which challenges previous estimates in this region, is not necessarily an overestimation.