Pollen analysis
The origin of the shola forest and grassland complex has been the subject of scientific debate. Some early researchers suggested that the floristic composition represents a stable final state or climax vegetation. This stability is maintained by climatic conditions such as frost which allow the grass to grow but kill off any forest seedlings. Others have suggested that the grassland may have been created and maintained by early pastoralists and point out that fire has a major role in the maintenance of the grassland. There is evidence for both and several features of the forest trees and the grasslands that have been considered and debated. Pollen analysis from bogs in the Nilgiris suggest that the complex of grassland and forest existed 35,000 years ago, long before human impact began. Long term studies on the dynamic processes of vegetation change continue.