Photosynthesis and carbon fluxes in agroforestry systems

IMG 1876

For a better understanding of biomass production of fast-growing trees in agroforestry systems more detailed ecophysiological informations and their annual carbon balances are required. Carbon gain by photosynthesis is a predominant factor for plant growth and to estimate biomass allocation at the tree, stand and landscape level. Hence, biochemical photosynthesis models are widely used to estimate diurnal and annual carbon uptake on the leaf level and scaling up to predict carbon fluxes on the canopy level. However, biochemical parameters are often difficult to determine under field conditions, and therefore we develop an empirical photosynthesis model based on gas exchange parameters and their dependence from microclimatic parameters, which can be easily obtained in the field. For up-scaling from leaf photosynthesis to annual tree carbon balance the structure of hedgerow, which is influencing the physiological functions and interactions must be taken into account. Our specific objectives are, therefore, to developed a leaf carbon model driven by light and modulated by temperature and air humidity. The seasonal variation of CO2 uptake and release can be then modeled and up-scaled to estimate the annual carbon fluxes of sun and shade leaves of black locust and poplars in agroforestry system.

In cooperation with University of Hohenheim, Institute of Botany.

       © Maik Veste 2017  -  Last update:  21JAN2017                            Impressum