A global scale mechanistic model of photosynthetic capacity (LUNA V1.0)

Geoscientific Model Development

C. J.Wilson¹  J. D.Muss¹  S. D.Wullschleger¹  J. B.Fisher¹  C.Xu¹  R. A.Fisher¹  J. A.Vrugt¹  A.Rogers¹  A. A.Ali¹  E. C.Massoud¹  N. G.McDowell¹  P. B.Reich¹ 

DOI  :  10.5194/gmd-9-587-2016

学科分类：天文学(综合)

来源: Copernicus Publications

【 摘 要 】

Although plant photosynthetic capacity as determined by the maximumcarboxylation rate (i.e., V_c, max25) and the maximum electron transportrate (i.e., J_max25) at a reference temperature (generally 25 °C) isknown to vary considerably in space and time in response to environmentalconditions, it is typically parameterized in Earth system models (ESMs) withtabulated values associated with plant functional types. In this study, wehave developed a mechanistic model of leaf utilization of nitrogen forassimilation (LUNA) to predict photosynthetic capacity at theglobal scale under different environmental conditions. We adopt anoptimality hypothesis to nitrogen allocation among light capture, electrontransport, carboxylation and respiration. The LUNA model is able toreasonably capture the measured spatial and temporal patterns ofphotosynthetic capacity as it explains  ∼  55 % of the globalvariation in observed values of V_c, max25 and  ∼  65 % of the variation in the observed values of J_max25. Modelsimulations with LUNA under current and future climate conditionsdemonstrate that modeled values of V_c, max25 are most affected inhigh-latitude regions under future climates. ESMs that relate the values ofV_c, max25 or J_max25 to plant functional types only are likely tosubstantially overestimate future global photosynthesis.

【 授权许可】

Unknown