INTRODUCTION
Disturbances can cause significant changes in ecological processes(1) and can be classified into three main types, based upon their intensity, duration and size, as large, medium and small.(2) There are many studies on the impact of disturbance upon natural resources or natural phenomena, such as storms, fire, etc., but also human activities which create severe and continuous impacts. Forests are one of the renewable resources that are disturbed by humans. There are many
changes in disturbed forests, such as species diversity and composition,(3-7) and soil properties and organic matter, which are ecologically sensitive in tropical forest ecosystems.(8,9) Agricultural activities are well known to not only reduce the biodiversity but also to diminish the soil quality and lead to the permanent degradation of land productivity, especially after prolonged practice in any given area.(10)