A4 Integration of ecophysiological processes and biotic interactions within a dynamic vegetation model (LSMBio): tree hydraulics, trait diversity, tree recruitment and insect herbivory [funded by DFG]
PI(s) for this project:
Prof. Dr. Thomas Hickler
This project describes how biological processes investigated in the partner projects of RESPECT will be integrated into a Land Surface Model (LSM) framework, which will enable us to address central hypotheses of the overall research unit (RU). The core of this work is based on LPJ-GUESS, a widely used Dynamic Vegetation Model (DVM), which has also been coupled with climate models and will serve as the biological component LSM-Bio of the overall framework developed by RESPECT. RESPECT will establish a very ambitious standardized measurement and plot system, which will provide a unique and excellent data base for further developing, parameterizing and evaluation our LSM-Bio. This holistic design includes measurements of plants traits, biotic interactions, soil characteristics, climate, and ecosystem functioning, including our two target functions (biomass growth and evapotranspiration), which are key to improving process representations in a LSM. Our LSM-Bio LPJ-GUESS already combines detailed representations of forest succession, which are important to account for biotic interactions, with generalized ecophysiological and biogeochemical process representations, which are strongly linked to ecosystem functioning and enable coupling with climate models. Thus, by bringing together the well-established generalised processes implementations in LPJ-GUESS and the extensive regional datasets, the envisioned LSM-Bio will capture ecophysiological and ecological processes at an, for a LSM, unprecedented level of detail, which is necessary to capture the complex ecology, ecosystem and climate dynamics of montane rainforests in Ecuador. Model developments will include schemes for plant hydraulic architecture, functional trait diversity and dynamics, biotic effects on forest regeneration and insect herbivory. It is the inclusion of all of these regionally relevant processes which will allow us to address three of the fundamental RU hypotheses outlined in the framework proposal concerning the resistance of the target functions to climate or land use change. In collaboration with the other partners, the LSM-Bio will also be coupled with an atmospheric model (LSMAtmo) and a hydrological model (LSM-Hydro) to form the LSM framework. Furthermore, inputs and outputs will be exchanged with land use and ecosystem services models to infer optimal land use strategies. Thus, the project here is strongly intervened with all other projects of the RU. The first phase, which we apply for here, will focuson plot-scale developments and evaluations. Spatial extrapolation and gridded simulations covering a larger area and more dynamic coupling between the model subcomponents of the overall LSM framework, including climate scenario simulations, are envisioned for the second phase.