Tree density, basal area and species diversity in a disturbed dry tropicalforest of northern India: implications for conservation

Background

Dry tropical forest communities are among the world’s most threatened systems. Rapid measures are required to protect and restore them in degraded landscapes. For planning conservation strategies, there is a need to determine the essential measurable properties, such as number of species and basal area, that best describe the dry forest vegetation and its environment, and to document quantitative relationships among them.

Research goals & methods

This paper examines the relationships between forest basal area and diversity components (number of species and evenness) for a disturbed dry tropical forest of northern India. Data were collected from five sites located in the Vindhyan dry tropical forest of India, selected on the basis of satellite images and field observations to represent the entire range of conditions in terms of canopy cover and disturbance regimes. Across sites, diversity and tree density were positively related with total tree basal area. Considering basal area as a surrogate of biomass and net production, diversity is found to be positively associated with productivity. A positive relationship between basal area, tree density and species diversity may be an important characteristic of the dry forest, where recurring disturbance does not permit concentration of biomass or stems in only a few strong competitors. However, the relationships of basal area with density, alpha diversity and evenness remain statistically significant only when data from all sites, including the extremely disturbed one, are used in the analysis

Conclusions & takeaways

To enhance the tree diversity of these forests, the variability in tree basal area should be reduced by regulating local disturbances. Conservation activities, particularly fuelwood plantations near human settlements, deferred grazing and canopy enrichment through multi-species plantations of nursery-raised or wild-collected seedlings of desirable species within the forest patches of low basal area, may help attain restoration goals. The success of reforestation programs depends on successful collaboration with forest-dwelling communities.