Long-term changes in precipitation and temperature patterns and their possible impacts on vegetation (Tolfa-Cerite area, central Italy)

Climate change is a major global issue that impacts vegetation, agriculture, biodiversity and human safety. These impacts are predicted to be intense in the Mediterranean region. The aim of this paper is to define how local climatic trends are affecting plant communities in the Tolfa-Cerite area (Northern Latium), which is a semi-coastal area with Mediterranean to broad-leaf vegetation. Climate data analysis covered a long time period (1951-2007), considering 18 gauging stations. Data were analyzed using geostatistical methods and descriptive statistics. Climate trends and drought indicators, in relation to different vegetation associations, were analyzed using the zonal statistic tool (ArcGIS). During the investigated period, rainfall showed a uniform decreasing trend, while temperature increased, with an irregular trend. The specialization of climatic data showed a shift towards a thermo-Mediterranean bioclimate. Local climatic trends showed to have more severe impacts on specific plant communities (mesophilous forests, endangered shrubland-pastures, relict associations of meadows, etc). The observed trends towards aridity occurred in many areas covered by vulnerable plant communities. Considering the predicted changes in climate conditions for the Mediterranean area, these communities will face a further aridity increase. A permanent monitoring of these communities may increase the effectiveness of conservation policies and sustainable regional planning