A forest may be defined as the land mass occupied with high density of trees. A forest collectively comprises not only the community of just plants, tress, herbs and shrubs; but also the animals, birds, insects and micro-organisms as well. It is an ecosystem of the relationship between biotic (living) and abiotic (Non-living like soil, climate and water) components. It functions as habitat for a variety of organisms, thus constituting one of the most important aspects of the Earth's biosphere. The Forest cover in India is 678,333 sq. km and constitutes 20.63% of its geographical area. Among this dense forest constitutes 390,564 sq. km (11.88%) and open forest 287,769 sq. km (8.75%). The geographical area of U.T. Chandigarh is 114 sq. km and another 26 sq. km of hilly area which has been declared as 'Sukhna Wildlife Sanctuary'; which was acquired for soil conservation works. The total forest area of Chandigarh in 2001 was just 39 sq. km and the other tree cover was 2 sq km only (SFR 2001). However, due to the continuous efforts of the Forests Department along with the other departments of UT, Chandigarh, the area under forests has now increased to 48.03 sq. Km and the tree cover to more than 9 sq. km (till 2015). Thus, the total green cover (forest cover tree cover) of Chandigarh as per F.S.I. report 'SFR-2015' is 40.73% of its total geographical area.
* Less than one hectare area of Sukhna Sanctuary may be under encroachment due to non demarcation of interstate boundary between U.T. and Haryana. Administration has taken various steps to conserve the biodiversity in forest area such as eradication of exotics species like Lantana which adversely affects the growth of indigenous species. Forest department has set target to plant lakh of saplings every year and always achieve more than that. The details of the different aspects of forests area of Chandigarh are described as follows: