Plant biodiversity data are prerequisites for the sustainable management of a forest. We used quantitative ecological tools to determine the species composition, diversity (richness and evenness), population structure, distribution patterns, and regeneration status of trees in a Tropical Moist Sal Forest of Eastern Ghats, India. For this purpose, a field inventory was conducted during 2020–2022 in sixteen 1.0 ha forest stands along a human-induced disturbance gradient. A total of 161 species (61 trees, 40 shrubs, 60 herbs) belonging to 77 families and 143 genera were recorded in the 16.0 ha of forest area. The results revealed a significant (p < 0.01) decrease in the tree and shrub species density, basal area, species richness, and diversity along the gradient of disturbance. However, in the case of herbs, the Shannon–Weiner diversity index increased significantly (p < 0.01) with increasing disturbance levels. Irrespective of forest types and disturbance levels, the tree diameter class (10–30 cm) accounted for the highest stem density in the forest. A mixed trend was found in the case of the basal area; the >41 cm diameter class constituted the highest basal area in the Pure Sal Forest while the 10–30 cm class was in the Moist Deciduous Forest without Sal. Tree species richness was found higher in lower diameter classes. Disturbances impacted the distribution pattern of trees; in the Pure Sal Forest, the contagious distribution of trees were 61.54%, 40%, and 12.5% in undisturbed, low-disturbed, and moderately disturbed sites, respectively. The percent of trees showing random and regular distribution increased with the increased level of disturbance in all forest types. The number of tree species having good regeneration decreased with the increased disturbance intensity in all forest types. Frequent grazing, repeated forest fires, and poor soil seed banks at the Moderately Disturbed site were the main reasons for the poor/no regeneration of Pterocarpus marsupium, Adina cordifolia, Terminalia bellerica, and some other economical species. Significant changes in structural attributes of the tree community revealed the impact of human-induced disturbances in the Moist Sal Forests of Eastern Ghats. The disturbance mosaics promoted the growth of many invasive weed species and lianas, depleting the number of valuable species in the forest. This study suggests the adaption of sustainable biodiversity conservation approaches through the active participation of the tribal so that the remnants the Moist Sal Forests of Eastern Ghats can be controlled to prevent further degradation.

The present study investigates the influence of Sal-dominated forests on the floristic composition, diversity and distribution pattern, and population structure of associated trees in a part of Eastern Ghats. Two forest communities viz., Sal-dominated Moist Deciduous Forest (SDMDF) and Moist Deciduous Forest without Sal (MDFWS) were selected for the study. Both these forests had sandy loam and acidic soil, though organic carbon was relatively higher (0.61%) in SDMDF than MDFWS (0.22%). While the SDMDF had 77 species (28 trees, 24 shrubs and 25 herbs) belonging to 51 families and 67 genera, the MDFWS had 111 species (44 trees, 22 shrubs and 45 herbs) belonging to 64 families and 104 genera. While Dipterocarpaceae was the dominant family in SDMDF, Combretaceae was dominant family in MDFWS. Both forest types showed an inverse J-shaped population structure indicating regenerating population. Phyllanthus emblica in SDMDF and Pterospermum xylocarpum and Schrebera swieteioides in MDFWS showed no regeneration. The results suggest that MDFWS maintain higher species diversity and ecosystem vitality than the SDMDF.