Water erosion is a major cause of desertification and reforestation is the major means of control.
One of the major causes of environmental degradation in Spain is forest fires. Other causes include logging, over-grazing and agriculture in marginal areas. Reforestation has been extensively carried out to combat desertification and more than 2.5 million hectares have been reforested since 1940. Over the last few years there was a sizable drop in reforestation, due to lack of cooperation by private landowners due to a lack of incentives, criticism by the environmental movement on the use of pine species, and the absence of legal instruments that provide incentives. The new national plan is attempting to remedy these problems.