The diversity of the natural environment, which controls the intrinsic quality of the natural resource base which is utilized for production. It includes soil characteristics and their productivity, the biodiversity of natural (or spontaneous) plant life, and of the soil biota. It takes account of physical and chemical aspects of the soil, surface and near-surface physical and biological processes, hydrology, microclimate, and also variability and variation in all these elements (Brookfield and Stocking (1999) Glob. Env. Change 9, 2). Geertsima and Pojar (2007) Geomorph. 89, 1–2 recognize several types of biophysical/ecological diversity: site diversity, soil diversity, and derivative habitat or ecosystem (including aquatic ecosystems) diversity.