INTERRELATIONSHIPS BETWEEN LAND ABANDONMENT AND LAND DEGRADATION - A CASE FROM THE ECUADORIAN-ANDES

Although accelerated rainfall runoff and soil erosion in inhabited mou ntain regions are often linked to cultivation practices on steep hills ides, fields that have been abandoned can pose an even greater risk of rapid runoff and soil erosion. This paper presents new evidence of la nd degradation resulting from land abandonment in the Ecuadorian Andes and examines the Andean case in light of recent research on land aban donment from the Pyrenees and Himalaya. The Ecuadorian data, based on 109 field rainfall simulation experiments, indicate that runoff and er osion rates on abandoned/fallow fields are significantly higher than t hose of cultivated lands. Analyses of total percent carbon show abando ned/fallow field soil samples to contain significantly less organic ma tter than those under other land uses. Continued degradation and high runoff coefficients in abandoned/fallow fields in both the Andes and t he Pyrenees are linked to the ongoing, informal use of these lands for grazing. Active management strategies are required to reverse the res ulting scenario of increasing land degradation.