Leaf chlorophyll content as a proxy for leaf photosynthetic capacity

作者：Holly Croft, Jing M. Chen, Xiangzhong Luo, Paul Bartlett, Bin Chen, Ralf M. Staebler · 发表于：Global Change Biology · 年份：2016 · DOI：10.1111/gcb.13599 · 被引用次数：749 · 研究领域：Plant Water Relations and Carbon Dynamics、Remote Sensing in Agriculture、Plant responses to elevated CO2

Abstract Improving the accuracy of estimates of forest carbon exchange is a central priority for understanding ecosystem response to increased atmospheric CO 2 levels and improving carbon cycle modelling. However, the spatially continuous parameterization of photosynthetic capacity (Vcmax) at global scales and appropriate temporal intervals within terrestrial biosphere models ( TBM s) remains unresolved. This research investigates the use of biochemical parameters for modelling leaf photosynthetic capacity within a deciduous forest. Particular attention is given to the impacts of seasonality on both leaf biophysical variables and physiological processes, and their interdependent relationships. Four deciduous tree species were sampled across three growing seasons (2013–2015), approximately every 10 days for leaf chlorophyll content (Chl Leaf ) and canopy structure. Leaf nitrogen (N Area ) was also measured during 2014. Leaf photosynthesis was measured during 2014–2015 using a Li‐6400 gas‐exchange system, with A‐Ci curves to model Vcmax. Results showed that seasonality and variations between species resulted in weak relationships between Vcmax normalized to 25°C ( ) and N A rea ( R 2 = 0.62, P < 0.001), whereas Chl Leaf demonstrated a much stronger correlation with ( R 2 = 0.78, P < 0.001). The relationship between Chl Leaf and N Area was also weak ( R 2 = 0.47, P < 0.001), possibly due to the dynamic partitioning of nitrogen, between and within photosynthetic and nonphotosynth...