This project tests a Dynamic Global Vegetation Model (DGVM) using reconstructions of past vegetation for North America and Europe based on paleoecological data. The DGVM is driven by past climate simulated with a fully coupled General Circulation Model (GCM), and the paleovegetation reconstructions are taken from continental scale databases of pollen and plant macrofossil data covering North America and Europe. Past vegetation can also serve as a direct proxy of past climate variations, and recent studies have shown that a DGVM can be used to help interpret the climate signal from pollen and macrofossil data. These techniques allow assessment of the role of non-climatic factors (e.g., CO2) in driving vegetation change. The project is able to identify and reduce bias in climate reconstructions for glacial periods, where these factors are significantly different from the present day.
DGVMs are one of the primary tools used to understand how terrestrial ecosystems might be affected by future climate change under various scenarios. By studying past periods, the predictive ability of these models in simulating ecosystem change under conditions that are different from the present day can be tested. The results from the model runs can also be used to investigate past changes in services provided by terrestrial ecosystems, including carbon sequestration and water resources. The work will also provide an assessment of the GCM used to simulate past climates, which will help to understand its skill in simulating future global change. The project results will include a consistent dataset of environmental conditions covering the last 21000 years. This will be made publicly available at the end of the project, and will provide a context for archeological studies and studies of land-surface history and processes. These results will be transformed into publicly accessible online teaching resources.
