Stem xylem-specific hydraulic conductivity (KS) represents the potential for plant water transport normalized by xylem cross section, length, and driving force. Variation in KS has implications for plant transpiration and photosynthesis, growth and survival, and also the geographic distribution of species. Clarifying the global-scale patterns of KS and its major drivers is needed to achieve a better understanding of how plants adapt to different environmental conditions, particularly under climate change scenarios. Here, we compiled a xylem hydraulics dataset with 1,186 species-at-site combinations (975 woody species representing 146 families, from 199 sites worldwide), and investigated how KS varied with climatic variables, plant functional types, and biomes. Growing-season temperature and growing-season precipitation drove global variation in KS independently. Both the mean and the variation in KS were highest in the warm and wet tropical regions, and lower in cold and dry regions, such as tundra and desert biomes. Our results suggest that future warming and redistribution of seasonal precipitation may have a significant impact on species functional diversity, and is likely to be particularly important in regions becoming warmer or drier, such as high latitudes. This highlights an important role for KS in predicting shifts in community composition in the face of climate change.
Bibliographical noteFunding Information:
We are grateful to the editor and reviewers for their constructive suggestions and comments on an earlier version of this manuscript. We thank Brendan Choat for his suggestions on data collection, Megan K. Bartlett and Yusuke Onoda for their comments on the manuscript, and Zeqing Ma for his suggestions on figure presentation. We also thank Xiaojuan Liu and Shaowei Jiang for their data contribution. This work was funded by the National Natural Science Foundation of China (31825005 and 31570405), and the Institution of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences (ISEE2018YB01). The authors declare no conflict of interest.
- functional types
- hydraulic diversity
- species distribution
- water transport
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't