Surrounded by tea estates, eucalyptus plantations and other exotic plants, the patchy grasslands in Valley View along the Grand Duff Road in Udhagamandalam are one of the few remaining remnants of the expansive grasslands that once carpeted the slopes of the upper Nilgiris.
After the introduction of invasive, exotic species of flora such as eucalyptus, wattle and blue gum by the British, and the proliferation of tea estates, most of the grasslands that used to be ideal habitats for herbivores have disappeared.
The invasive species taking over the grasslands has had cumulative negative impact on local ecology and the environment. While the invasive species consume lots of water, the loss of the grasslands has led to depletion of groundwater level.
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The native inhabitants of the Nilgiris, the Todas, have seen the effects, said Dr. Tarun Chhabra, a dentist and an expert on Toda culture. “The Todas make use of a grass known as Eriochrysis rangachari, a type of swamp grass endemic to the Nilgiris, to build huts,” said Mr. Chhabra.
While the grass used to be found across the upper slopes of the Nilgiris, it has now become restricted to a few patches in Kundah due to the disappearance of wetlands.
N. Mohanraj, a renowned conservationist, said that grasslands are important as they replenish streams and small water sources. “Grasslands act like a sponge, as below the surface for around 50 cm is packed with humus. Moreover, grasslands also harvest water from mist all around the year and are the most important source of water for small streams,” he said.
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Such is the effect of the invasive species on pristine grasslands, that wattle has been sprouting sporadically inside the Mukurthi National Park.
Srinivas R. Reddy, Field Director of the Mukurthi National Park, said that 75 hectares of the park were cleared of wattle in 2013, while 125 were cleared in 2014 and 50 hectares were cleared in 2015, in the 78 sq.km park.
“We have a systematic removal process, whereby the wattle trees are felled. But the trees disburse seed material, which sprouts even after the main tree is removed. So we remove the seedlings every year for three years,” said Mr. Reddy.
As the wattle are extremely resilient, the field director has sent a proposal for the removal process to be continued for a period of five years.
Dr. V. Ramsundar, formerly with the horticulture department in Udhagamandalam, said that in many parts of the Nilgiris, Pennisetum clandestinum, known as kikuyu grass, introduced by the British from parts of Africa, have taken over vast swathes of territory.
However, even though they are alien species, he believes that the grass is not harmful to the overall ecological balance. “Herbivores consume kikuyu grass, which also prevents soil erosion and forest fires from spreading,” said Mr. Ramsundar.
Though the forest department has taken up commendable afforestation policies, with the reintroduction of Shola tree species to the landscape, experts believe that there needs to be an equal focus on ensuring that grasslands are also restored. Dr. Tarun Chhabra said that the forest department is replacing invasive species with Shola, which he said was not ideal.
Dr. S. Rajan, Scientist (in-charge), Central Council for Research in Homoeopathy, said that the restoration of grasslands was a feasible project.
“We need to remove eucalyptus and wattle from the landscape, and in around 5 to 10 years, the grasslands will regenerate themselves when left undisturbed,” he said.