Co-regulation of photosynthetic capacity by nitrogen, phosphorus and magnesium in a subtropical Karst forest in China

Jing Wang; Xuefa Wen; Xinyu Zhang; Shenggong Li; Da-Yong Zhang

doi:10.1038/s41598-018-25839-1

Co-regulation of photosynthetic capacity by nitrogen, phosphorus and magnesium in a subtropical Karst forest in China

Sci Rep. 2018 May 9;8(1):7406. doi: 10.1038/s41598-018-25839-1.

Authors

Jing Wang^{1

2

3}, Xuefa Wen^{4

5}, Xinyu Zhang^{6

7}, Shenggong Li^{1

2}, Da-Yong Zhang³

Affiliations

¹ Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
² College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100190, China.
³ School of Life Sciences, Beijing Normal University, Beijing, 100875, China.
⁴ Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China. wenxf@igsnrr.ac.cn.
⁵ College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100190, China. wenxf@igsnrr.ac.cn.
⁶ Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China. zhangxy@igsnrr.ac.cn.
⁷ College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100190, China. zhangxy@igsnrr.ac.cn.

Abstract

Leaf photosynthetic capacity is mainly constrained by nitrogen (N) and phosphorus (P). Little attention has been given to the photosynthetic capacity of mature forests with high calcium (Ca) and magnesium (Mg) in the Karst critical zone. We measured light-saturated net photosynthesis (A_sat), photosynthetic capacity (maximum carboxylation rate [V_cmax], and maximum electron transport rate [J_max]) as well as leaf nutrient contents (N, P, Ca, Mg, potassium [K], and sodium [Na]), leaf mass per area (LMA), and leaf thickness (LT) in 63 dominant plants in a mature subtropical forest in the Karst critical zone in southwestern China. Compared with global data, plants showed higher A_sat for a given level of P. V_cmax and J_max were mainly co-regulated by N, P, Mg, and LT. The ratios of V_cmax to N or P, and J_max to N or P were significantly positively related to Mg. We speculate that the photosynthetic capacity of Karst plants can be modified by Mg because Mg can enhance photosynthetic N and P use efficiency.

Publication types

Research Support, Non-U.S. Gov't