Context-A Coonoor-based trust proposes to plant more than 10,000 trees in the Nilgiris. However, there is a problem: almost all of them are exotic flora — from avenue trees such as jacaranda, podocarpus, pine and bottlebrush.

Challenges of planting exotic trees:

• Exotic trees such as pine, podocarpus and cypress trees have a huge impact on soil chemistry on the ground where they are planted, preventing native grass, plants and herbs from taking root underneath the canopy.
• It has a knock-on effect on wildlife resulting in their vacating the areas.
• When exotics take root in a particular area they increase the water demand in that region, impacting not just the Nilgiris but other districts further downstream that rely on rivers emanating from the hills.
• Growing exotic trees in the Nilgiris is counterproductive to conservation and ensuring biodiversity.
• The roots of these trees are very shallow and the trees can be uprooted by high velocity winds and heavy rain, which characterise the monsoons in the Nilgiris.

Why Exotic trees:

• Forest Department has only enough native trees to afforest their reserve forests, so they do not give out any saplings to private individuals.
• They lead to better soil stability of the slopes on which they are planted.

Nilgiri hills

• It forms parts of western ghat shared among Tamil Nadu, Kerala, Karnataka.
• Its northern boundary is formed by Moyar river and southern by Pal ghat.
• Moyar river separate it from karnataka plateu while pal ghat separate it from Annaimalai.
• It is part of Niligiri biosphere reserve.