Soil degradation, landscape and climate variations in a Mediterranean agro-forest system (Thriasio, Greece): proposal for a desertification indicator using time series analysis

As a contribution to soil degradation and desertification monitoring in the northern Mediterranean basin, the present study investigates long-term climate variations in the traditional agro-forest system of Thriasio Plain (Greece) by examining month average temperature, precipitation, relative humidity, Standardised Precipitation Index (SPI) and de Martonne index time series between 1958 and 2011. In the last twenty years, the area experienced an increased anthropogenic pressure due to urbanisation and industrialisation processes. Results indicate a moderate trend towards a warmer and drier climate with a slight increase in the range of the observed values for precipitation and temperature. Relative humidity decrease by 0.1% per year at both year and month base. Results point out the complexity of climate variations at the local scale and the importance of air humidity trends depending on rainfall and temperature regimes in the Mediterranean basin.