Barren soil undergoes several changes in its physical and chemical properties when brought under tree cover. Trees influence the soil by providing shade and litter at the surface and through their roots in the sub-surface layers.

Over the last four decades exploitation of natural resources to meet increasing societal demands for land based products has caused significant changes in land use and land cover not only in nature's best gifted regions but also environmentally sensitive arid regions.

The planning of conservation measures to conserve water and soil resources taking hydrological planning unit as micro-watershed is considered to be effective.

Nanjido, an island in Republic of South Korea, at the end of the Han River was made a landfill site in 1978. Fifteen years later, the site had to be closed due to the extensive damage caused by the pollution of soil, air, surface and underground water. In 1996, the Seoul Metropolitan Government decided to continue till 2020.

Biomass estimation and productivity studies were conducted in 3, 6 and 9 years old plantations of Dalbergia sissoo in sodic lands of Sultanpur District in Eastern Uttar Pradesh, India. A set of regression equations for biomass production per unit area was also developed to be applied on regional basis.