- The Shola forests of South India derive their name from the Tamil word solai, which means a ‘tropical rain forest’.
- Classified as ‘Southern Montane Wet Temperate Forest’ the Sholas are found in the upper reaches of the Nilgiris, Annamalai’s, Palni hills, Kalakadu, Mundanthurai and Kanyakumari in the states of Tamil Nadu and Kerala.
- These forests are found sheltered in valleys with sufficient moisture and proper drainage, at an altitude of more than 1,500 metres.
- The upper reaches are covered with grasslands, known as Shola grasslands.
- The vegetation that grows in Shola forests is evergreen. The trees are stunted and have many branches. Their rounded and dense canopies appear in different colours.
- Generally, the leaves are small in size and leathery. Red-coloured young leaves turning into different colours on maturity is a prominent characteristic of the Shola forests.
- Epiphytes like lichens, ferns and bryophytes usually grow on the trees.
- The occurrence of Himalayan plants like rhododendron in these Shola forests is a mystery.
Significance of Sholas
- Sholas thus act as ‘overhead water tanks’. They play a major role in conserving water supply of the Nilgiris’ streams.
- The trees are slow-growing varieties which produce timber of little or no value and probably take at least a century to mature.
- The rolling grasslands found on top of the Western Ghats, enhance the beauty of the region. Usually, Shola forests and grasslands are found in a ratio of 1:5.
- The rain received from the Southwest and Northeast monsoons is harvested by the Shola forest-grassland ecosystem, leading to the formation of the Bhavani river that finally drains into the Cauvery.
- Thus, the Shola forest-grassland ecosystem of the Nilgiris, also supports the prosperity of Cauvery delta farmers.
- As tree species of the montane, evergreen forests are flammable, regeneration of any Shola tree species is completely prevented except for Rhododendron nilagiricum, the only Shola tree that can tolerate fire.
Threats to Shola forests
- the Sholas have begun to gradually shrink due to the introduction of alien plant species and annual fire occurrences.
- Alien species like Sticky Snakeroot, Gorse and Scotch Broom introduced during British rule, have encroached upon the grasslands.
- During 1840, tree species such as Acacia and Eucalyptus were introduced from Australia.
- Afterwards, between 1886 and 1891, Pine and Cypress were introduced, again from Australia. As the alien species grew, the forests and grasslands gradually became degraded and shrank.
- In addition, unscientific agricultural practices like growing tea on the slopes, cattle grazing and fuel wood collection have become serious causes for degradation.
- Unregulated tourism has created concrete jungles, traffic congestion and caused the generation of garbage.
Wrath of Eucalyptus
- During 1849, the extent of Shola forests was 8,600 hectares (ha), grasslands 29,875 ha and agriculture was 10,875 ha.
- No wattle or eucalyptus was planted in the area at that time.
- The comparison of the results of the 1849 and 1992 studies shows that cultivation of tea, wattle and eucalyptus has reduced the Shola forest-grassland ecosystem to a great extent.
- After realizing the seriousness of the situation, the government banned the planting of wattle and eucalyptus completely in 1987.
- Ecological restoration and biodiversity conservation were given importance.
- Under the Hill Area Development Programme since the mid-1980s, seedlings have been planted in degraded patches and protected with chain-link fences to restore the forests.
- Special Shola forest protection committees were formed involving teachers, nature lovers, ecologists, environmentalists, students and villagers in the Nilgiris.
- They were motivated to remove plastic garbage from the nearby forests, protect Shola trees, remove alien species and learn about the importance of the Sholas.
- Presently, the Tamil Nadu forest department is now focusing on eradicating wattle, providing fencing and planting shola seedlings in degraded shola forests.