Last month, I passed the PhD application at DESS, Tsinghua University. I’m very excited that I can continue my study at Tsinghua University next year as a member of LPICEA. Considering my educational background and the development of LPICEA，I will focus on the improvement of vegetation dynamics in Noah MP (a land surface model) (Niu et al. 2011) and this is also my research proposal at THU.
My first PhD project is about improving the photosynthesis module in Noah MP base on the optimality principle of P model. This will allow us to quantify the potential effect of photosynthetic acclimation on future climate-carbon feedback. Currently, the simulation ability of photosynthesis diverges markedly between different models due to the uncertain photosynthetic traits and parameters (Rogers et al. 2017). For example, as a key parameter of photosynthesis, Vcmax (the capacities for carboxylation) is set as a constant value for the same vegetation type in Noah MP, which may contribute to error for the simulation because Vcmax acclimates to environmental variables with time and space (Zhang et al. 2015). Another parameter, leaf internal carbon dioxide (CO2) partial pressure (Ci) is a convergence value obtained by iterative calculation in Noah MP, therefore it is time-consuming. Based on a simple evolutionary optimality hypothesis, a gross primary production model (the P-model) provides a robust theory and a potential basis for the reformulation of the photosynthesis in next-generation earth system models. Therefore, the formula for these parameters can be turned into a very simple form after we consider the optimality principle (Wang et al. 2017).
We are looking forward the simulation ability of photosynthesis can be improved after considering the optimality principle. Meanwhile, we also wonder to know how would plant adaptive behavior modify the interaction between atmosphere and terrestrial.
Niu, G.-Y., Z.-L. Yang, K. E. Mitchell, F. Chen, M. B. Ek, M. Barlage, A. Kumar, K. Manning, D. Niyogi, E. Rosero, M. Tewari & Y. Xia (2011) The community Noah land surface model with multiparameterization options (Noah-MP): 1. Model description and evaluation with local-scale measurements. Journal of Geophysical Research, 116.
Rogers, A., B. Medlyn, J. Dukes, G. Bonan, S. von Caemmerer, M. Dietze, J. Kattge, A. Leakey, L. Mercado, Ü. Niinemets, I. Prentice, S. Serbin, S. Sitch, D. Way & S. Zaehle (2017) A roadmap for improving the representation of photosynthesis in Earth system models. New Phytologist, 213, 22-42.
Wang, H., I. C. Prentice, T. F. Keenan, T. W. Davis, I. J. Wright, W. K. Cornwell, B. J. Evans & C. Peng (2017) Towards a universal model for carbon dioxide uptake by plants. Nat Plants, 3, 734-741.
Zhang, Y., L. Guanter, J. A. Berry, J. Joiner, V. D. T. Christiaan, A. Huete, A. Gitelson, M. Voigt & P. K?Hler (2015) Estimation of vegetation photosynthetic capacity from space-based measurements of chlorophyll fluorescence for terrestrial biosphere models. Global Change Biology, 20, 3727-3742.