Covering one-third of Earth’s landmass, forests perform vital tasks across the globe. Different types of forests in India and the world provide green cover to being the biosphere reserves, forests have a lot of importance with over 1.6 billion people, including over 2,000 native cultures directly depending upon the forests. The forests provide livelihoods, shelter, fuel, food and hence are an important part of our ecosystem. However, despite all of these benefits, deforestation has been a growing concern over the years. To help create awareness about this, and to engage more people around the world in environment-friendly practices, the March 21 is celebrated as the World Forest Day.
United Nations General Assembly passed a resolution on December 21, 2012, to declare March 21 as the international forest day. With the resolution, United Nations hopes to encourage its member states to actively participate in events related to forests and promotion of the various benefits of them. Activities like tree planting have also been made part of the event. The aim is also to raise awareness amongst people over the role of forests in poverty eradication, environmental sustainability, and for food security.
Forests provide shelter to over 80 per cent of the terrestrial species of animals, plants and insects and hence with the widespread destruction that is happening at the rate of 13 million hectares per year, these species have been having a hard time adapting. This has further led to a loss of some species from their natural environment and from the habitat thus leading to fears of extinction.
Types of Forests in India
‘Forests and energy’ have been decided as the theme for this year’s international forest day. The reason behind this theme is to showcase the importance of wood energy in improving people’s lives, mitigating climate change, and in empowering sustainable development.
Wood is a source of renewable energy used all over the country and the world extensively for a long list of resources. Not only is it used for energy generation but also for creating furniture, for paper, construction or other items of daily use and the list is endless.
Wood energy helps deal with climate change and works in tandem with sustainable development, showcasing the further need for the forests. Forests are known to hold energy content around ten times of the annual energy consumption of the world!
India has various types of forests in different parts of the country. The total forest and tree cover in India is 79.42 million hectare, approximately 24.16 per cent of India’s geographical area (India State of Forest Report 2015, Ministry of Environment and Forests, Government of India). Description of major types of forests in India according to Sir Harry George Champion and S.K. Seth (1968) is as follow –
Tropical Wet Evergreen Forests
These are tall, dense and multi-layered forests generally found in regions having rainfall in excess of 2500 mm and are distributed mainly in the Western Ghats, Upper Assam, Arunachal Pradesh, Andaman and Nicobar Islands. The flora in these forests has Malayan affinities. Bamboos and canes occur in specific locations. Ferns and epiphytes are also common.
Tropical Semi-Evergreen Forests
These forests occur in areas adjoining tropical wet evergreen, and form a transition between evergreen and moist deciduous forests. They are found locally in the Western Ghats, Assam, Arunachal Pradesh, parts of Odisha and Andaman and Nicobar Islands. The canopies are not continuous and species richness is lower. Bamboos, canes, ferns, and epiphytes are abundant.
Tropical Moist Deciduous Forests
These forests are distributed mainly in the Western Ghats, Assam, Arunachal Pradesh, Mizoram, Bihar, West Bengal, Odisha, and Uttaranchal. This forest type occurs in a strip along the foothills of Himalaya, another strip along the east side of Western Ghats and in a large area in Chhota Nagpur and north-east hills. These forests are common in areas where rainfall is 1500-2000 mm with a dry season of 4 to 6 months. The most important forest communities are those consisting of sal (Shorea robusta) and teak (Tectona grandis).
Littoral and Swamps Forests
These forests consist of evergreen species of varying densities and height. These forests are mostly in their developmental stage; they occur throughout the country, wherever wet and waterlogged conditions prevail. The littoral and tidal forests occur along the coast, the latter being especially associated with deltas of larger rivers. Swamp forests occur in north-east India along major river systems. Mangrove forests are generally dominated by trees of the genera – Rhizophora, Avicennia, Sonneratia, Bruguiera Kandelia and Ceriops.
Tropical Dry Deciduous Forests
These forests occur from Kanyakumari to the foothills of the Himalaya in irregular wide strips in areas having rainfall between 750 mm and 1250 mm. They are concentrated in Rajasthan, Madhya Pradesh, Maharashtra, Odisha, Uttar Pradesh, Karnataka, Andhra Pradesh and Tamil Nadu. Dry teak and dry sal communities predominate in the southern and northern regions respectively. In some areas both these species are absent and a mixture of trees like Anogeissus pendula, Boswellia serrata, Hardwickia binata, Acacia nilotica, Madhuca indica, and Butea monosperma occupies the area. Acacia catechu and Dalbergia sissoo are conspicuously present on newly formed soils.
Tropical Thorn Forest
These forests occupy a large strip in Southern Punjab, Haryana, Northern Gujarat and almost entire Rajasthan, where rainfall is about 250 mm and 750 mm. Such forests are also found over a large area in the upper Gangetic plains and Deccan plateau.These forests are open, consisting of short trees, generally belonging to thorny leguminous species. The characteristic species include Prosopis cineraria, Acacia leucophloea, Acacia nilotica, Ziziphus spp, and Salvadora spp. Acacia tortilis and Prosopis chilensis have been widely planted in this region.
Tropical Dry Evergreen Forest
These forests are found in a relatively small area on the Carnatic coast, which receives little or no summer rainfall. The forests are low but often dense with hard-leaved evergreen trees in which thorny species predominate. The characteristic species are Memecylon edule, and Maba buxifolia.
Sub Tropical Broad leaved Hill Forest
These forests occur in the lower slopes of the Himalaya in Bengal and Assam and on other hill ranges such as Khasi, Nilgiri, Mahabaleshwar, Pachmarhi, Amarkantak and Parasnath. Important species in the south- ern hills are Syzygium cumini, Ficus spp, and some species of Lauraceae. The northern form consists of species like Quercus and Castanopsis.
Sub Tropical Pine Forest
Sub-tropical chir pine (Pinus roxburghii) forest occurs throughout the central and western Himalaya, and Khasi pine forest occurs in Khasi hills. These forests are almost pure throughout their zone of distribution. The understorey is also not pronounced. These are distributed in several Himalayan states.
Sub Tropical Dry Evergreen Forest
These forests occur in areas with low rainfall and consist of xerophytic, thorny and small-leaved evergreen species. Such forests are localized in the northwest corner of the country. The typical species are Olea cuspidata and Acacia modesta in the top canopy and Dodonea shrub in the degraded forests.
Montane Wet Temperate Forest
These forests are a characteristic feature of the eastern Himalaya and are found between 1800 m and 3000 m elevation in high rainfall areas. Some of the tops of southern hills, e.g. Nilgiris, are also occupied by these forests. In northern form of these forests, characteristic genera are Quercus, Castanopsis, Machilus, and Rhododendron. In the south- ern hills, important species belong to Syzygium and Ternostroemia. Rhododendron nilagiricum is an important component in Nilgiri hills. The forests are luxuriant with dense undergrowth.
Himalayan Moist Temperate Forest
These are commercially important forests and are found between 1500 m and 3000 m elevations in the Himalaya. These are con- centrated in the central and western Himalaya, except in areas where rainfall is below 1000 mm.These forests are classified into two forms; the lower form consists of Quercus leucotri- chophora, Quercus. Floribunda, Pinus wallichiana and Cedrus deodara. As the altitude increases, the upper form consisting of Abies pindrow, Picea smithiana, and Quercus semecarpifolia becomes dominant.
Himalayan Dry Temperate Forest
These are open evergreen forests with open scrub undergrowth. These forests occur in the upper ranges of the Himalaya in low rainfall areas. These forests consist of both coniferous and broad-leaved species. In the western Himalaya, the characteristic species are Pinus gerardiana, Cedrus deodara and Quercus ilex. At higher elevation, Juniperus macrop– oda communities are also found. In the eastern Himalaya, the common species are from Abies and Picea. In higher hills, Juniperus wallichiana is common. Locally, between 2500 and 4000 m elevation, a few other species like Larix griffithiana, Populus euphereti– ca, Salix spp., Hippophoe spp. and Myricaria spp. also occur.
Sub Alpine Forest
These forests occur throughout the Himalaya above 3000 m elevation up to the tree limit. Some of the characteristic species in the western Himalaya are Abies spectabilis and Betula utilis while those in the eastern Himalaya are Abies densa and Betula spp. High- level blue pine (Pinus wallichiana) forests occur on exposed sites. Rhododentron forms the understorey.
International forest day marks the importance of forests in our lives. One of the major sources of oxygen, forests’ have a greater role to play in the earth’s ecosystem. And hence need to be conserved with proper mandates on protection of forests!