Climate change, impacts and vulnerability in Europe ... - MemoFin.fr

Climate impacts on environmental systemscan convert peatlands into carbon sources ratherthan sinks. Likewise, inappropriate cultivation ofsoils and the application of nitrogen fertilisers canlead to emissions of CO 2and N 2O.Selection of indicatorsThis section presents three indicators that measureimportant climate-sensitive properties of soils:• Soil organic carbon: Soil organic carbon ispotentially impacted by climate change, andchanges in soil organic carbon in turn have animpact on climate change.• Soil erosion: Soil erosion by water and wind isalready affecting soils across Europe, therebythreatening many of the services soils provide.as a consequence of climate change may indicate anextinction risk of local soil biota (see Box 3.4).Finally, when documenting and modelling changesin soil indicators, it is not always feasible to tracklong-term changes (signal) given the significantshort-term variations (noise) that may occur(e.g. seasonal variations of soil organic carbon dueto land management). Therefore, detected changescannot always be attributed to climate changeeffects, as climate is only one of the soil-formingfactors. Human activity can be more determining,both in measured/modelled past trends (baseline),and if projections including all possible factors wereto be made. The latter points towards the critical roleof effective land use and management in mitigatingand adapting to climate change.• Soil moisture: Soil moisture is a key factorfor ecosystems, which is determined by soilcharacteristics, vegetation and climatic factors.Furthermore, the final Section presents informationon the effects of negative precipitation anomalies ona major soil function, biomass production. Anothersoil-related indicator, which relates to changes inpermafrost, is presented in Section 2.3.6.Uncertainty and data gapsQuantitative information, from both observationsand modelling, on the past trends and impactsof climate change on soil and the various relatedfeedbacks, is very limited. For example, data havebeen collected in forest soil surveys (e.g. ICP Forests,BioSoil and FutMon projects), but issues with surveyquality in different countries makes comparisonbetween countries (and between surveys) difficult(Hiederer and Durrant, 2010). To date, assessmentshave relied mainly on local case studies thathave analysed how soil reacts under changingclimate in combination with evolving agriculturaland forest practices. Thus, European-widesoil information to help policymakers identifyappropriate adaptation measures is absent. There isan urgent need to establish harmonised monitoringnetworks to provide a better and more quantitativeunderstanding of this system. Currently, EU-widesoil indicators are (partly) based on estimates andmodelling studies, most of which have not yet beenvalidated. Nevertheless, in absence of quantification,other evidences can indicate emerging risks. Forexample, shifting tree lines in mountainous regionsClimate change, impacts and vulnerability in Europe 2012147