Temporal Shifts in Community Dominance and Regenerative Capacity of Tropical Forests in Central India

Tropical forests cover approx. 17 million hectares of India’s total geographical area and are facing serious threats from deforestation, habitat fragmentation, and climate change, leading to biodiversity loss and ecosystem degradation. Our study enumerates the shifts in community composition of Central Indian tropical forests through Preservation Plots over a 30-year period. A total of 99 tree species (including 3 lianas) belonging to 79 genera and 32 families were identified by conducting the two-phytosociology survey. In 1991, 87 tree species were recorded, while in 2021, only 79 trees species were recorded. Sorensen similarity and Bray-Curtis dissimilarity indices were used to assess the changes in species composition across 125 quadrats, each 0.1 hectares in size. In which 87 plots resulted in higher dissimilarity index (0.2 to 1.0) indicating considerable shifts in composition whereas, only 28 plots exhibited higher similarity index (0.0 to 0.8) revealing minimal change and 10 plots remained unchanged in their species composition. The species dominance based on Importance Value Index indicated a remarkable change of community shift. Also, the regenerative potential of trees revealed 59 regenerating species from two surveys. In 1991, 51 regenerating species were recorded, with Fabaceae being the most dominant family. In 2021, it decreased to 44 species, with Fabaceae still being dominant. We obtained significant changes (p=  0.05) after comparing the individuals density (ha-1), basal area (m2 ha-1), and diversity indices between 1991 and 2021. Each Preservation Plot exhibited unique patterns of change in species composition and their regeneration ability. At saplings and seedlings stage, we investigated change in density/ha of each species throughout the Preservation Plots and found significant increasing and decreasing trend of regeneration (*). It is concluded that Preservation Plots plays vital role in long-term monitoring and assessment of change in community biodiversity, species structure and composition.