Large uncertainties exist on the current carbon dioxide uptake by European forests. One of the reasons is, that the high variation of observed CO2 uptake rates cannot be directly attributed to forest canopy traits or environmental conditions. Therefore, we propose to look much closer at the processes that infer the carbon budgets of forests than done in previous work. With the proposed Fellowship the two involved scientists aim at advancing knowledge on the determinants for the gross canopy photosynthesis rates (Pg) at the example of three European temperate forests. An intensive training programme is proposed in two major areas of concern: (i) training in eco-physiological field methods and (ii) training in advanced methods to examine the mathematical properties of biophysical models, and, thereby, of the biophysical systems themselves. In both training areas an exceptional expertise exists at the Host Institution. Complementary expertise is brought in by the Fellow. A key element of the collaborative Pg research is the application of the three dimensional forest stand model MAESTRA. During the Fellowship structural and physiological model parameters will be collected in two Danish and one German forest. Emphasis will be placed on the accurate determination of t he quantum yield of photosynthetic electron transport. Simulated Pg will be compared with independent CO2 and water vapour flux observations at different spatial scales. Rigorous statistical analyses will detect systematic and random differences between the model output and the observations. These will be interpreted in terms of model performance and flux data quality. A model sensitivity study using a Monte Carlo framework will yield the desirable uncertainty estimate of the model output. Finally, the mode l will be used to explain differences in CO2 uptake rates and patterns across the three forests in terms of canopy traits and weather conditions.
Call for proposal
See other projects for this call