Soil erosion in Mediterranean chestnut tree plantations at risk due to climate change and land abandonment

Chestnut cultivation is a type of traditional centennial exploitation in southern areas of Extremadura. Currently, chestnut is in danger of extinction due to the effects of climate change, some diseases (e.g. Cryphonectria parasitica) and land mismanagement. The high temporal variability of rainfall leads to soil erosion in chestnut cultivation. New forms of management are proposed to try, among other things, to reduce soil losses. This study quantifies soil losses in areas under tree canopies and open areas considering two different age plantations; 1990s and 1960s. To achieve the proposed goal 18 erosion plots were installed as paired plots under tree canopies and open areas in both plantations. The total amount of rainfall per event, tree cover, bare soil, runoff coefficient and sediment concentration were also measured in every plot. The results showed that the highest percentage of bare soil (> 45%) coincides with the period of greatest tree cover (> 75%). The open areas and the youngest plantation showed soil losses higher than the areas under the tree and the oldest plantation. In addition, soil losses increase as higher percentages of bare soil are recorded. We conclude that the size of the trees and a better soil stability in older plantations help reduce soil losses.