Du land tenure systems paly a role in conserving tree diversity? A case study from coffee agroforestry systems of Kodagu, India

The Kodagu district in South India is located in the central part of Western Ghats, one of the world hot spots of biodiversity. This region was densely forested up to the mid-Nineteenth Century and is one of the major areas of coffee cultivation in India. The coffee-based agroforestry systems (AFS) of Kodagu are good examples of human-managed forests that contain a good stocking of diverse tree species. Hence, these farms can be called coffee agroforests. The management of vegetation or canopy cover in these coffee AFS is mainly regulated by the rights given to the planters. The trees in the coffee AFS could be owned either by the forest department or the plantation owner. Though there are 32 distinct tenure systems, they can be broadly grouped into two major categories, redeemed and unredeemed lands. These complex land tenures determine timber extraction and in turn their structure and diversity. The present study indicates that density and basal area of trees were not significantly different among the redeemed and unredeemed plantations, which could be attributed to the replacement of harvested trees by the farmers. On the other hand, the diversity of trees was higher in unredeemed plantations compared to plantations under redeemed tenure. As coffee AFS under unredeemed tenure are more diverse, they in turn provide better ecological and economic benefits to planters such as better quality coffee, lesser insect pest damage, and additional returns from timber and pepper for which tree standards are essential. These coffee agroforests also serve as corridors for unique fauna such as elephants and birds. Hence the tenure of the land is a major factor that regulates the type of trees and in turn the biodiversity present in coffee plantations and at the landscape level. (Texte intégral)