Wentao Luo, Robert J. Griffin-Nolan, Lin Song, Niwu Te, Jiaqi Chen, Yuan Shi, Taofeek O. Muraina, Zhengwen Wang, Melinda D. Smith, Qiang Yu, Alan K. Knapp, Xingguo Han, Scott L. Collins
Global climate change is expected to increase rainfall variability, potentially increasing the frequency of extreme droughts during this century. Intensified drought will impact ecosystem functioning, with many ecosystems expected to experience a reduction in primary productivity. Understanding how plant communities will respond to these droughts is a major challenge in ecology. Few studies, however, have investigated both the drought resistance and recovery of community-scale traits, with even less research on the relative effects of inter- vs. intra-specific trait variability on such responses.
To address this knowledge gap, here we describe results from a long-term drought and recovery experiment conducted in cold-semiarid grasslands of China (Inner Mongolia). We found that drought altered both inter- and intra-specific trait variability, leading to significant shifts in some CWM traits. Interestingly, these CWM traits completely recovered following the extreme drought. The shifts in CWM traits in response to drought were primarily driven by intraspecific trait adjustments, while both components contributed to recovery. Importantly, inter- and intra-specific adjustments in CWMs did not always occur in the same direction, with antagonistic effects leading to lack of a response in CWMs in some cases and enhanced responses in others.
These results have important implications for evaluating the impacts of future drought on cold-semiarid plant communities and could improve predictive models of ecosystem sensitivity to extreme drought.