Although broad-scale inter-specific patterns of leaf traits are influenced by climate, soil, and taxonomic identity, integrated assessments of these drivers remain rare. Here, we quantify these drivers in a field study of 171 plant species in 174 sites across Chinese grasslands, including the Tibetan Plateau, Inner Mongolia, and Xinjiang. General linear models were used to partition leaf trait variation. Of the total variation in leaf traits, on average 27% is due to taxonomic or phylogenetic differences among species within sites (pure species effect), 29% to variation among sites within species (pure site effect), 38% to joint effects of taxonomic and environmental factors (shared effect), and 6. 2% to within-site and within-species variation. Examining the pure site effect, climate explained 7. 8%, soil explained 7. 4%, and climate and soil variables together accounted for 11%, leaving 18% of the inter-site variation due to factors other than climate or soil. The results do not support the hypothesis that soil fertility is the "missing link" to explain leaf trait variation unexplained by climatic factors. Climate- and soil-induced leaf adaptations occur mostly among species, and leaf traits vary little within species in Chinese grassland plants, despite strongly varying climate and soil conditions.
Bibliographical noteFunding Information:
Acknowledgments The authors are grateful to Cunzhu Liang, Zhongling Liu, Zongyuan Zhu, and Qing Du for plant species identification in the field, and Shilong Piao for providing climate data. This research was supported by the National Natural Science Foundation of China (Grant 30870381 to J.-S.H. and A3 Foresight Program to J.F.) and the Ministry of Science and Technology of People’s Republic of China (Project 2007BAC06B01 to J.-S.H.). J.-S.H. was supported partially by a Sino-Swiss Science and Technology Cooperation Research Fellowship Program of the Swiss National Science Foundation.
- Functional traits
- Inner Mongolia
- Leaf economics spectrum
- Soil fertility
- Tibetan Plateau