The Nilgiri plateau was once covered entirely by a mosaic of shola forests and grasslands. This ecology was important in supporting large herds of herbivores and other animals, and also served as a crucial watershed for the plains around. For thousands of years, indigenous peoples communities lived in harmony with this ecology. Within a pan of 200 years all this changed. In the 1800s, 'exotic' species were introduced to meet ornamental, firewood, timber and industrial needs. Over the course of two centuries, exotic species like tea and plantation crops were often planted en masse, indiscriminately.
Large scale planting triggered certain more invasive varieties to spread into areas they had never been seen before, replacing large parts of a native grassland that overran 70% of the plateau. By 1988, over 11,000 hectares of grasslands were converted to plantations.
They now grow unchecked in many former shola forests and grasslands. Today man-animal conflict has escalated in the Nilgiris. Invasive shrubs like 'prosopis' can be toxic and cause severe indigestion and tooth decay to wildlife, who then stray into fields more often due to the absence of fodder in the wild. Regenerating native species proves to thus be a multi pronged solution to replenishing feeding grounds of wild animals, regenerating hydrologies and streams, and enriching the soil
About the ecological history of this landscape in the book Voice of a Sentient Highland