Task 5.3.2 CARAIB Dynamic Vegetation Modelling

Process-based dynamic vegetation models (DVM) are tools of choice to study the carbon cycling , the impacts of droughts on ecosystems and forest fires and the species or biome distribution in relation with past, present and future climate change.
With an improved dynamic scheme, CARAIB vegetation model has been used to investigate the impacts of future climate change on European forest ecosystems under several 1951-2100 climate projections. The net primary productivity (NPP) should increase in high latitudes and altitudes (by up to 40 % or even 60-100 %)  due to longer growing seasons while it should decrease in temperate (by up to 50 %) and in warmer regions, e.g. Mediterranean area (by up to 80 %), due to summer droughts more recurrent than in the present (Dury et al., 2011). The more frequent and more severe soil water stress episodes, especially in southern and Central Europe, also lead  to an increase of NPP interannual variability. In the Mediterranean basin, the area burned by wildfire can be expected to increase by a factor of 3-5 at the end of the 21st century compared to present. Future species or biome distributions are also simulated to locate the areas of future potential ecosystem disruption.
A dispersal module has been implemented into CARAIB.  European scale simulations have been performed over the Holocene to study postglacial re-colonization of the continent by three temperate tree species (Abies alba, Fagus sylvatica and Picea abies). The relative roles that played the climate conditions, the species dispersal capacities and the inter-specific competition in the re-colonization rates have been studied. Simulated speeds and routes of species spread are compared with pollen and macrofossil records. Simulations highlight the important role of competition in species dispersion.

Publications:

• Dury, M., Hambuckers, A., Warnant, P., Henrot, A., Favre, E., Ouberdous, M. & François, L., (2011). Responses of European forest ecosystems to 21st century climate: assessing changes in interannual variability and fire intensity. IForest 4, 82-99.
• Dury, M., Lehsten, D.,  Dullinger, S., Polska, A., Hülber, K.,  Cheddadi, R., Laborde, H., Sykes, M.T.,  Hickler, T., Singarayer, J., François, L. & Warnant P., 2011. Simulating the Holocene re-colonization of Europe by tree species using dynamic vegetation models. European Geosciences Union, General Assembly 2011, Vienna, Austria, April 3-8, 2011. Geophys. Res. Abstracts, Vol. 13, EGU2011-11169-1, 2011.