The footprint of marginal agriculture in the Mediterranean mountain landscape: An analysis of the Central Spanish Pyrenees.

Agriculture forms an essential part of the mountains of the Mediterranean. For centuries, large areas were cultivated to feed the local population, with highly marginal slopes being tilled at times of heavy demographic pressure, using the shifting agriculture system. A great deal of agricultural land was abandoned during the 20th century, giving rise to secondary succession processes that tend to eliminate the agricultural footprint. However, revegetation is a highly complex process leading to areas with dense, well-structured plant cover, and other open areas of scrubland. This article studies the role of traditional agriculture in the deterioration of the landscape. By using experimental plots in the Central Pyrenees to reproduce traditional agriculture and abandonment, maps of field types, and current uses and ground cover, it could be confirmed that shifting agriculture has caused very heavy soil loss, which explains the deterioration of the landscape on several slopes. Burning scrub and adding the ash to the soil as a fertilizer did not greatly help to improve soil quality, but caused high rates of erosion and a very slow process of regrowth. The average data obtained from the shifting experimental plots recorded losses of 1356kghayears, 1.6 times more than the plot of fertilized cereal, and 8.2 times more than the dense scrub plot. Following abandonment, losses in the shifting agriculture plot were almost three times higher than the abandoned sloping field plot. Traditional shifting agriculture in the Pyrenees is the main cause of the deterioration of the landscape 50-70years after agriculture ceased.