"Many uncertainties still exist about forest dynamic responses to climate change. One major source of uncertainty is how mechanisms at the scale of individuals are linked to ecosystem-level functioning (i.e. carbon exchange, water balance and biodiversity). This project will address this question by developing a modeling framework to analyze forest-climate interactions and ecological mechanisms controlling the response of forests to climate change. The framework will be used to develop a mechanistic forest ecosystem model and examine the impact of multiple, interacting effects of climate change on forests at a broad spatial scale (>10 km²). This aim will be exemplified addressing forest functioning of primary temperate rainforests of southern South America (SSA, 37-43°S). Tree species traits that can account for the variation in tree species dominance along large-scale climatic gradients will be identified, and used to constrain parameters controlling species responses to climate. The model will be calibrated and tested using an extensive field data collection of SSA forests obtained by this project. Simulation experiments will be conducted to investigate multiple, interacting effects of climate change on forests under different future scenarios. Results from this project will contribute in narrowing uncertainties related to future ecosystem services provided by primary forests under a changing environment. This research can contribute to determine climate change threats on biodiversity of SSA and produce a high quality baseline data for future research. By estimating carbon and water fluxes from SSA forests at regional scales, the proposed research will contribute for the first time to understanding ecosystems feedbacks with the atmosphere in this region. The results will help to assess the role of these forests in the carbon cycle. The generalized modeling approach will also produce a tool applicable to other forest ecosystems."