Context
- According to a report filed by an expert committee formed by the Madras High Court, expanding plantations like tea and eucalyptus along with foreign and invasive species in the Nilgiris can wipe out Shola vegetation.
Flora:
The grasslands consist of different species of grass and mostly the following species are seen widely,
- Chrysopogon zeylanicus
- Cymbopogon flexuosus
- Arundinella ciliata
- Arundinella mesophylla
- Arundinella tuberculata
- Themeda tremula
- Sehima nervosum.
The Shola forests exhibit high endemism due to their pronounced isolation and distinct climatic conditions. The plants and animals residing here originate exclusively in this particular region, making them distinct from species found anywhere else in the world.
Fauna:
Animals exclusive to these forests flourish, as some of these creatures have uniquely adjusted to the distinct landscape found only in this world. This region exclusively harbors numerous amphibian species, along with select mammal species and primates native to the southern Western Ghats
Some of them are,
Large animals like Tiger, Elephants, Leopard, and Gaurs are also found to inhabit the grassland-shola complex.
Details About Shola Vegetation:
- 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, Anamalais, Palni hills, Kalakadu, Mundanthurai and Kanyakumari in the states of Tamil Nadu and Kerala.
- These forests are found valleys with sufficient moisture and proper drainage, at an altitude of more than 1,500 metres. Grasslands, known as Shola grasslands, cover the upper reaches.
- 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. These are remnants of the vegetation driven to South India during the Quaternary Ice Age, about 2.6 million years ago, with subsequent changes in the tropics of South India.
- Sholas play a major role in conserving water supply of the Nilgiris’ streams. “The Sholas of the plateau are slow-growing varieties which produce probably take at least a century to mature. So they are of immense use in protecting source of water supply.” Sholas thus act as ‘overhead water tanks’.
- The rain received from the Southwest and Northeast monsoons is harvested by the Shola forest-grassland ecosystem. Thus 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.
- This unique landscape is native only to the Southern Western Ghats.
- They are found only in the high altitude mountains of the states Karnataka, Kerala and Tamil Nadu. Nowhere else in the world exist such a kind of forests.
Concerns
- Unfortunately, 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.
- Land use studies undertaken on the Nilgiri Biosphere Reserve between 1849 and 1992 show the extent of the damage. During 1849, the extent of Shola forests was 8,600 hectares (ha), grasslands 29,875 ha and agriculture was 10,875 ha. During that time, individuals did not plant wattle or eucalyptus trees in the area.
- In 1992, researchers discovered that the extent of Sholas was 4,225 ha, grasslands covered 4,700 ha, agriculture occupied 12,400 ha, tea plantations encompassed 11,475 ha, wattle plantations spanned 9,775 ha, and eucalyptus plantations covered 5,150 ha.
- 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.
Expert Committee Findings:
- According to a report filed by an expert committee threatening expansion of foreign and tea plantations threaten native dry deciduous, moist deciduous and thorn forests and grasslands there.
- This change in vegetation will result in loss of water sources and is already leading to massive landslides.
- The committee recognises the deleterious impact of invasive species like eucalyptus, tea plantations and wattle and naturalised alien species like Lantana camara, Opuntia stricta, Chromolaena odorata, Parthenium hysterophorus and Senna spectabilis on the Shola forest and grasslands.
- The wattle is replacing grasslands and Shola forests. The plantations of Eucalyptus, pines and cupressus have virtually wiped out grasslands and sholas. The massive tea gardens also replaced the vegetation.
- The expert committee visited the Mudumalai Tiger Reserve and found that around 60 per cent (690 square kilometres) of the entire core and buffer area of the reserve is under invasion.
- The domination of invasive species in the Western Ghats was between 65 and 75 per cent, according to data presented by the state government.
- Invasive species occupied areas showed no secondary or fresh growth of indigenous trees, plants, or grass, which elephants rely on as food. Moreover, the attempts made by the forest department to manage the invasive alien species has had little or no success, according to the report.
Committee Recommendations:
- The committee suggested in the report, removal of exotics and invasive alien species and subsequent ecological restoration of weed-free landscapes. This will require well-knitted management structure and resources.
- The committee recommended that there is an urgent need to map the extent of foreign plantations. The spread of invasive alien species and loss of grasslands in each forest division of the Nilgiris.
FAQs about Shola vegetation
Shola ecosystems, located in the Western Ghats of India, stand out as distinctive montane forests renowned for their abundant biodiversity and landscapes veiled in mist.
Invasive species outcompete native plants, disrupt the food chain. They alter the habitat’s physical structure, leading to a decline in native species.
Individuals can support conservation efforts by participating in reforestation drives, spreading awareness, and supporting local initiatives focused on protecting Shola ecosystems.
Invasive species threaten several native species in Shola ecosystems, including the Nilgiri marten, the Nilgiri tahr (an endangered mountain goat), and various endemic plant species like the Neelakurinji flower.
Invasive species often have rapid growth rates and high reproductive capabilities. They might lack natural predators or face fewer limitations in their new environment, allowing them to outcompete native species for resources and take over the habitat.