Climate change and forest ecosystem dynamics

An evaluation of process-based models of forest growth showed that several models, including FORGRO, were able to produce accurate estimates of carbon and water fluxes at several forest sites of Europe. Responses were in relatively good agreement with the expected responses obtained by experimental studies, and models were able to deal with new conditions and explore the likely effects of climate change.

The effect of climate change on forest development was assessed for three forests stands in The Netherlands using a gap model which was made climate sensitive by including the effects of climate change scenario IPCC IS92A on growth (FORGRO results), phenology (FORGRO results), and seed production (regression analysis). Results showed that climate change is likely to cause subtle changes rather than abrupt changes in forest development in the Netherlands, and that forest development on sandy soils in the Netherlands is not likely to be influenced significantly by climate change over the coming 50 years.

The impact of climate change on the production, nature and recreation values of forests was studied using a simple economic model, and showed that response are likely to be relatively small during the first century, and are related to the successional status of the forest. Linking of detailed process-based models with gap models enables interpretation of climate change effects beyond a change in tree growth only, and is an important tool for investigating the effects of climate change on the development of mixed forests. The modelling approach presented in this project (process-based growth models -> gap models -> economic model) is a useful tool to support policy decisions in the light of climate change and forests.