Temporal (1958-1995) pattern of change in a cultural landscape of northwestern Portugal: implications for fire occurrence

In this paper we test the hypothesis that landscape changes in a region of Northern Portugal (Minho) in the last 40 years could be predicted from soci oeconomic and political history. The major predicted changes were related t o agricultural abandonment and afforestation. We further predicted that the se changes contributed to increased fire risk. Analysis of aerial photograp hy for the years 1958, 1968, 1983 and 1995 in a study area of 3700 ha revea led a significant decline in agricultural areas and low shrublands and an i ncrease in tall shrublands and forests. This represented a 20-40% increase in fuel accumulation at a landscape level, suggesting that the abandonment of farming activities is a major driving force of increasing fire occurrenc e in the region. With one exception, all the predictions were partly or tot ally confirmed. This study confirms that socioeconomic factors might explai n a significant part of the variation in landscape composition across time, in the Mediterranean region.