1. Global change impact on ecosystems Reinhart Ceulemans and Ivan Nijs University of Antwerp, Department of Biology (UA-PLECO)

2. Impact on ‘structure, function and distribution of ecosystems’ (productivity, control measures, C sequestration) Impact on ‘water and hydrology’ (hydrological basins, flow, sensitive fen ecosystems) Impact on ‘biodiversity’ (extinction, control measures) Interactions ‘ecosystems - CO 2 and other GHG’ (terrestrial sink, land use, soil acidification) ‘What drives ecosystem changes ?’ (one or more factors, social ‘drivers’)

3. C-stocks in terrestrial ecosystems and soil (F. Veroustraete, VITO and B. Van Wesemael, UCL) StocksPer unit area (ton C / ha) Totals Belgium (kton C) Forest biomass94.453,800 Humus in forests61.535,000 Soil, 0-30 cm58 (10-190)144,000 Soil, 0-100 cm98 (18-986)241,000

4. Fluxes of C - terrestral ecosystems and soil (F. Veroustraete, VITO and B. Van Wesemael, UCL) FluxesPer unit area (ton C / ha / year) Total Belgium (kton C / year) NEP all vegetation 4.814,600 NEP forest accretion 5.02,800 Forest felling2.11,200 Soil via management ?500-800

5. Terrestrial ecosystems = carbon sink? Net ecosystem-productivity (NEP) Belgium: 14,500 kton C per year (1997) (C-Fix model, VITO)

6. Total amount of C in soil is much larger than in wood and forests Geographical link between carbon stock in the soil and vegetation productivity Agricultural zones: low soil carbon Source: (Lettens et al., 2004)

7. Evolution of C-sequestration (L. François, ULg) Carbon sequestration will increase under global change conditions, but in function of: (i) age; (ii) changing weather conditions; (iii) forest management.

8. Plant and animal species disppear today by approximately 1,000 x the natural speed of extinction climate change pollution overhunting and overfishing habitat-destruction biological invasions landscape fragmentation eutrophication

9. Population viability analysis (E. Le Boulangé, UCL) 1775 1973 Lienne vallei, Lierneux

10. current situation Model: predicts population size of vulnerable species under different scenarios of change + grazing + warmer climate

11. CARAIB model (Ulg, L. François)

12. Agricultural area: 50% grassland Grassland species adapted to a moderate climate aprmayjunjulaugsep +-+- Growth response to a warmer climate

13. “Change is seldom driven by a single factor” (H. Geist, UCL) CO 2 concentration: higher Air temperature: higher Climate: more extreme Biodiversity: lower Invasive exotics: more Habitat fragmentation: stronger … interaction?

14. Exotic invasive plants