Shrubland ecosystems in Europe under climatic changes: preliminary results from a Mediterranean-type ecosystem

The future climate is likely to be warmer and severe summer droughts are likely to occur more often. Elevated temperatures and extended droughts are predicted to have a large influence on the functioning of natural and semi-natural environments both directly and through interactions with land management and pollutant loading. Thus, climatic changes may have particular strong effects on vulnerable ecosystems, which are already subjected to other stresses such as elevated N deposition, intensive grazing or the risk of fire. VULCAN - Vulnerability assessment of shrubland ecosystems in Europe under climatic change (see the companion paper submitted by Beier and Spano) - is a common European research project conducted in Denmark, United Kingdom, the Netherlands, Spain, Italy and Hungary investigating the effects of climate change on the functioning of vulnerable European shrublands. Six shrubland ecosystems are studied along a temperature, moisture and N-deposition gradient. Experimental manipulation of the climatic conditions at field scale is conducted employing a newly developed "night time warming" technique and an automated covering system to extend summer drought. The differences in important ecosystem processes among different sites may indicate the long-term consequences of climatic changes, or it may serve as a strong tool for evaluating the sensitivity of terrestrial ecosystem under different climatic conditions. In this paper the experimental site located in Sardinia, Italy, is presented. The site is a typical Mediterranean-type ecosystem located in a firebreak strip where a natural re-colonization process started in 1993 after fire and mechanic clearings. The experimental plots, covered by vegetation with a maximum height of 1 m, include sclerophyll species, some scattered shrubs and several herbaceous plants. Preliminary results on the responses in ecosystem functioning and processes (effects on soil, plants, and soil water) to the experimental treatments (warming and drought) are reported.