India, with the second largest global population, was once a land of dense jungles, exotic wildlife, and incredible culture. It still is known for all three of the above, although the hardest hit might be the forests of this beautiful land. Today, India’s forests make up approximately 21% of her land area, although reports debate the exact percentage. However, one thing is clear – forests are a crucial component to maintaining India’s abundant biodiversity and retaining its title as one of the world’s 17 most biodiverse nations.

We live in a time of unprecedented forest degradation, courtesy of a lack of concern for our natural resources and a lack of awareness by those supposedly in charge of protecting them. It falls upon scientists to take forth the issue and spread awareness, as I hope to do today.

So, what are these forests of India, and what biodiversity do they hold in their depths? Why do we need to care about their survival?

The major forest types of India and their locations in the subcontinent can be seen in the above map. India lies at the juncture of three biogeographic realms – the Indo-Malayan , the Eurasian, and the Afro-tropical. The country is a megabiodiverse region, but faces growing anthropogenic pressures on its wild spaces. Forests comprise an important part of India’s wilderness, providing habitat to a plethora of wildlife and hosting over 17,500 species of flowering plants. They are also the birthplace of India’s watersheds, providing potable water to a rising population and supporting agriculture as well.

Forests can be classified based on various factors. The most common is the climate factor; temperature and precipitation dictate the type of vegetation found in an area, tree density, tree height, and soil moisture and organic matter. Forests can also be classified based on elevation; evergreen tree species tend to occur at higher elevations while deciduous forests reign supreme at lower elevations. Another classification method is tree leaf type (needles vs. broad-leaves). In this anthropogenic era, forests are also known based on the level of human alteration or disturbance that they face. Primary, or old-growth, forests are undisturbed relics of the past. Secondary and tertiary forests face increasing levels of alteration and regrowth of dominant plant species, with an ever-changing species composition.

In 1968, Champion and Seth came up with a classification system for Indian biomes and delineated 16 major forest types and 221 minor forest types in the subcontinent. Reddy et al. (2015) went a step further and classified forest types in India into multiple levels of forest classes. The total forest area was deemed to be 6,25,565 sq. km. (19.03% of total geographic area in 2015) and Level 1 forest types included the following:

1. Tropical moist forest
2. Tropical dry forest
3. Subtropical forest
4. Temperature forest
5. Sub-alpine forest

Of these types, tropical moist forests cover the largest extent of India’s geographical area (49%), followed by tropical dry forests (36.17%) and subtropical forests (7%). However, the authors went further and sub-divided these climatic forest types into two more levels of subtypes based on phenology and biogeography, not just climate. The following table shows the different types of forests in the different levels:

The Deccan Plateau has the highest forest cover of India’s biogeographic zones, followed by Northeast India and the Eastern Himalayas. Moist deciduous forests are the most widely distributed forest type across the subcontinent.

Now, let’s take a look at a few choice forest types of India:

Tropical wet evergreen forests: Birds flutter beneath a dense canopy, the understory rustles with the sound of insects, amphibians, reptiles, and rodents. Small mammals scurry along, and larger mammals such as deer, gaur, and elephants keep a lookout for predators, which include the tiger, leopard, and wild dog. These are the forests of the Western Ghats, Northeast India, and the Andaman and Nicobar Islands, dense, remote, and relatively unexplored. The forests around Mysuru and on the drive to Ooty or other hill stations in the Karnataka-Tamil Nadu-Kerala area are examples of this forest type. These are where India’s old-growth, primary forests make their final stand. My fieldwork often leads me into these rainforests, where the chirping of birds, the eerie hooting call of langurs, and the sawing cry of the leopard are the music in my ears.  

Tropical dry evergreen forest: The drive from Karnataka into Tamil Nadu or Andhra Pradesh brings about a change in foliage. The lush wet rainforests of the Western Ghats make way for a drier, equally dense forest, home to wild dogs, sloth bears, and the tiny chevrotain (mouse deer). These forests are nestled in the rainshadow of the Western and Eastern Ghats, receiving moisture with the onset of the northeast monsoon in the winter months. Here, felling and land conversion has left tiny pockets of untouched forest, while most forests here are secondary growth with a relatively low canopy (10-m).

Subtropical dry evergreen forest: Short stubby trees and thorny evergreen shrubs distinguish this unique forest type from the others present in India. A long hot and dry season rules these forests, and trees retain their leaves year-round to prevent undue water loss. These forests are found in the Shivalik hills and the lower Himalayas, up to an elevation of 1500 metres. Birds call in high sweet tunes, sambar peer worriedly at passing people with large eyes, and leopards prowl through these forests in the late twilight hours. During my time in Mussoorie, and subsequent travels in Rajaji National Park, I encountered vast stretches of these forests, the gateway to the snowpeaks of the Greater Himalayas.

Tropical thorn forest: The rolling hills of the Aravallis give way to an expanse of low open forest, dry, dust-swept, and full of thorns. Nilgai rest beneath these thorny trees, wary of prowling tigers and Indian wolves. The yodeling of jackals cuts through the stillness of the night air, and sambar boom alarm calls in response. These are the thorn scrub forests of semi-arid Rajasthan, at the edges of the tiger haven known as Ranthambhore. Here, the greenery of the Aravalli Hills blends steadily into the Thar Desert, creating this semi-arid zone of trees, the last forest before the golden sands take over the landscape. Hardwood species, used to water scarcity, are prevalent, and winds whip a fine layer of sand and dust over vegetation here. The few rivers that carve a blue ribbon through the landscape are livegivers – the Chambal and her tributaries reign supreme in this region. In South India, thorn forests can be seen in southern Andhra Pradesh, northern Tamil Nadu, and parts of Deccan Karnataka.

India’s forests face a growing threat as the human population continues to rise and encroachment for development exceeds conservation efforts. Protected Areas (PAs) are some of the last strongholds for India’s forests, granting legal protection to the trees and wildlife that reside there. However, with the growth of settlements around PAs, even forests are no longer safe against human activities including felling, lopping, and the collection of non-timber forest products. Deforestation for development is a primary cause of forest fragmentation. Dams, barrages, roads and other linear intrusions, and plantations are some of the causes of deforestation.

India was famed for its dense jungles, which were immortalized in folklore and other literature. But will future generations ever see the grandeur of India’s forests, and her biodiversity, if conservation and preservation of these landscapes are not made forefront in the agenda of the government and people?