1. ICP Forests EB.AIR/WG.1/2011/5 2011 Report „Effects of air pollution on forests“ Two studies Forest soil condition Bruno De Vos et al. (FSCC at INBO, Belgium) Forest biodiversity under deposition impact Co-operation with ICP M&M Max Posch et al. (CCE) Hans-Dieter Nagel et al. (ÖKO-DATA) Data from ICP Forests (Levels I and II) EC (Regulation Forest Focus)

2. ICP Forests EB.AIR/WG.1/2011/5 Forest soil condition and its change Two forest soil surveys On more than 5.000 Level I plots ICP Forests:1986-1996 EC: 2004-2008 under Regulation (EC) 2152/2003 Forest Focus (application of ICP Forests methods) Present report focus on C/N ratio C/N index Base saturation pH

3. ICP Forests EB.AIR/WG.1/2011/5 C/N ratio In healthy forests: C/N ratio on forest floor (C/N FF ) higher C/N ratio in mineral soil (C/N MIN ) Under high N-pollution loads: C/N FF < C/N MIN  Useful indicator for excess N: C/N FF C/N index =--------- C/N MIN

4. ICP Forests EB.AIR/WG.1/2011/5 C/N index C/N index < 1 Organic matter and nutrient cycling disturbed Risk to forest health Areas of C/N index < 1 Red (France, Germany, Latvia) C/N index Lower in central/western Europe Higher in northern, eastern and southern Europe

5. ICP Forests EB.AIR/WG.1/2011/5 Base saturation Gradient Lower in northern Europe Higher in southern Europe Geologic origin Upper mineral soil (0-10 cm) Central Europe Soils with low base saturation (< 20%) Result of acid deposition Share of plots with low base saturation First survey: 48% Second survey: 28% Recovery

6. ICP Forests EB.AIR/WG.1/2011/5 pH Changes between two surveys Increase on plots with acid soils (pH < 4.0) Decrease on plots with less acid soils (pH > 4.0)

7. ICP Forests EB.AIR/WG.1/2011/5 Development of forest biodiversity Deposition scenario „NATIONAL“ Implementation of emission-related legislation in EU-27 (Latest version by CCE) Application of VSD+ 20 Level II plots 12 countries Changes from 2000 to 2050 C/N Base saturation Application BERN Results of VSD+ as input variables Response of plant communities simulated

8. ICP Forests EB.AIR/WG.1/2011/5 Results of BERN Adaptation of plant communities to site conditions High on 10 plots Full regeneration potential High vitality Moderate on 5 plots Low regeneration potential Reduced vitality Low on 4 plots No regeneration potential Low vitality

9. ICP Forests EB.AIR/WG.1/2011/5 Presently growing tree species Adaptation determined for Present time 2050 Site conditions predicted to deteriorate on 4 plots to improve on 3 plots For all 19 plots „target tree species“