Nitrogen and phosphorus availabilities interact to modulate leaf trait scaling relationships across six plant functional types in a controlled-environment study
Nitrogen and phosphorus availabilities interact to modulate leaf trait scaling relationships across six plant functional types in a controlled-environment study
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DOI：
10.1111/nph.14591
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发表时间：
2017-08-01
期刊：
影响因子：
9.4
通讯作者：
Atkin, Owen K.
中科院分区：
文献类型：
--
作者：
Crous, Kristine Y.;O'Sullivan, Odhran S.;Atkin, Owen K.
氮(N)和磷(P)在叶片代谢中起着关键作用，因此在田间研究中，化学成分性状与代谢率之间存在很强的耦合。然而，在这样的研究中，很难理清营养供应本身对性状-性状关系的影响。本研究评估了6种植物功能类型（PTFs） 37种植物在受控环境下，高氮和低氮（分别为5 mM和0.4 mM）和P（分别为1 mM和2 μ M）供应对光合作用(A)和呼吸(R)（黑暗和光明）的影响。当氮供应不受限制时，低磷供应增加了基于区域的对数-对数A-N或R-N关系的缩放指数（斜率），而在低氮供应下没有P效应。相反，A-P和R-P关系的标度指数受到P和N供给的影响。R: A和叶片R的光抑制均不受养分供给的影响。营养处理的光抑制率为26%；草本植物的光抑制程度低于木本植物。由于氮磷供应调节叶片性状-性状关系，下一代陆地生物圈模型在预测碳交换时可能需要考虑氮磷有效性的限制如何影响性状-性状关系。
Nitrogen (N) and phosphorus (P) have key roles in leaf metabolism, resulting in a strong coupling of chemical composition traits to metabolic rates in field-based studies. However, in such studies, it is difficult to disentangle the effects of nutrient supply per se on trait-trait relationships.Our study assessed how high and low N (5 mM and 0.4 mM, respectively) and P (1 mM and 2 mu M, respectively) supply in 37 species from six plant functional types (PTFs) affected photosynthesis (A) and respiration (R) (in darkness and light) in a controlled environment.Low P supply increased scaling exponents (slopes) of area-based log-log A-N or R-N relationships when N supply was not limiting, whereas there was no P effect under low N supply. By contrast, scaling exponents of A-P and R-P relationships were altered by P and N supply. Neither R : A nor light inhibition of leaf R was affected by nutrient supply. Light inhibition was 26% across nutrient treatments; herbaceous species exhibited a lower degree of light inhibition than woody species.Because N and P supply modulates leaf trait-trait relationships, the next generation of terrestrial biosphere models may need to consider how limitations in N and P availability affect trait-trait relationships when predicting carbon exchange.