Soil degradation and desertification induced by vegetation removal in a semiarid environment

Abstract

The fragile soils at the transition between semiarid and arid areas are continuously threatened by human activity, which frequently involves the elimination of plant cover. We studied the impact of vegetation removal on soil characteristics in senliarid Mediterranean Spain using two plots (15 m x 5 m), installed on a north facing slope of 23%.Vegetation was removed from one of the plots (disturbed plot), and changes in the soil characteristics were compared with an undisturbed control plot. Fifty-five months after vegetation removal the organic carbon content decreased bj 35%, the percentage of stable aggregates by 31% and soil bulk density increased by 8%.The models that best represented the changes of these parameters with time were linear equations. There were no significant differences between the water retention capacity or saturated hydraulic conductivity of the treatments. The rapid loss of soil organic matter and the consequences in terms of physical soil properties were considered to be the main factors in soil degradation. No symptoms of natural recovery were observed in the disturbed plot and the tendency was for a steady deterioration in soil behaviour. This means that human activity or climatic change leading to less vegetation could result in irreversible soil degradation in semiarid areas.

Causes and underlying processes of measurement variability in field erosion plots in Mediterranean conditions

“…The data recording period in this area extends from 1989 until 2003. Results of the studies carried out in this area using this set-up can be found in Castillo et al (1997), Albaladejo et al (1998) and Martínez-Mena et al (2000, 2002.…”

Climatic and anthropogenic controls of topsoil features in the semi‐arid East Asian steppe

“…Human activities have been commonly overestimated when identifying the causes of soil degradation [Lal et al, 1998]. Some researchers have recognized that climatic change leading to less vegetation could result in irreversible soil degradation in semiarid areas [Albaladejo et al, 1998], but they did not give a quantitative assessment. How and to what degree climate change will cause soil degradation at both global and regional scales remains unclear and thus to be further explored.…”

Requirements for success of reforestation projects in a semiarid low‐mountain region of the Jinsha River Basin, southwestern China

“…Chou (1987) reported that only shrubs and grasses could be grown in the arid and semiarid conditions. Albaladejo et al (1998) has observed that the fragile ecosystems at the transition between semiarid and arid areas are not able to recover fully after a severe disruption such as vegetation removal. However, in the central part of Yuanmou, Yunnan Province there is a history of six to eight years of successful reforestation projects (72-77 per cent survival) on areas of approximately 100 ha.…”