Plant stoichiometric coupling among all elements is fundamental to maintaining growth-related ecosystem functions. However, our understanding of nutrient balance in response to global changes remains greatly limited to plant carbon : nitrogen : phosphorus (C : N : P) coupling. Here we evaluated nine element stoichiometric variations with one meta-analysis of 112 global change experiments conducted across global terrestrial ecosystems and one synthesis over 1900 species observations along natural environment gradients across China. We found that experimentally increased soil N and P respectively enhanced plant N : potassium (K), N : calcium (Ca) and N : magnesium (Mg), and P : K, P : Ca and P : Mg, and natural increases in soil N and P resulted in qualitatively similar responses. The ratios of N and P to base cations decreased both under experimental warming and with naturally increasing temperature. With decreasing precipitation, these ratios increased in experiments but decreased under natural environments. Based on these results, we propose a new stoichiometric framework in which all plant element contents and their coupling are not only affected by soil nutrient availability, but also by plant nutrient demand to maintain diverse functions under climate change. This study offers new insights into understanding plant stoichiometric variations across a full set of mineral elements under global changes.
Bibliographical noteFunding Information:
We are grateful to the scientists who contributed the valuable data for this global synthesis. This study was financially supported by the National Natural Science Foundation of China (31625006, 31470528, 31600356), the International Fellowship Initiative, Institute of Geographic Sciences and Natural Resources Research, CAS (2017DS01), the Ministry of Science and Technology of China (2016YFC0501803), the Thousand Youth Talents Plan Project and the National Natural Science Foundation of China (41473068).
© 2018 The Authors. New Phytologist © 2018 New Phytologist Trust
- global changes
- natural environmental variation
- nutrient balance
- plant functions
- soil nutrient