Plant population mapping and quantitative assessment of peri-urban vegetation of Ranchi, eastern India

Abstract

The composition of species, as well as their population and regeneration status of tree species, provide an important ecological foundation for assessing the current state and rate of ecosystem degradation. Therefore, the present study aimed to determine the plant species composition with population and regeneration status of the 40 different tree species in peri-urban vegetation of Ranchi, eastern India using 52 belt transects each of 0.10 ha. A total of 58 different plant species of 49 genera and 26 families were recorded with the majority (86%) of native Indian origin species. The 14% of exotic origin species included dominant invasives in herb, shrub, and tree layers viz., Mesosphaerum suaveolens (L.) Kuntze. (2949 ind. ha⁻¹), Lantana camara L. (1667 ind. ha⁻¹), and Acacia mangium Willd. (33 ind. ha⁻¹), respectively. On the other hand, 59% of the total plant species were IUCN Red-listed including Endangered (Tectona grandis L.f.), Near Threatened (Aegle maremlos (L.) Corrêa), Data Deficient (Mangifera indica L.), and Least Concern (Dalbergia sissoo Roxb. ex DC). Total adult tree density and basal cover were 541 ind. ha⁻¹ and 24.93 m² ha⁻¹, respectively and Shorea robusta C.F.Gaertn. was the most dominant tree (295 ind. ha⁻¹) recorded in the majority of the studied patches (87%) where adult tree density (ind. ha^{− 1}) ranged from 10 to 1520 with a mean of 363 ± 49 (SE) signifying that the majority of the studied urban vegetation was Sal dominated forest patches. The total density of tree seedlings (22,627 ind. ha⁻¹) was highest in the studied peri-urban vegetation of Ranchi followed by total tree saplings density (2677 ind. ha⁻¹) and adult tree (GBH ≥ 10 cm) density (541 ind. ha⁻¹) signifying good regeneration status (density of seedlings > saplings > adults) of the peri-urban vegetation of Ranchi. was the most common human disturbance observed in 31% of the total studied patches. No regeneration of 56% of the total tree species, the prevalence of human disturbances in the 48% studied patches, and the occurrence of invasives in all three layers of vegetation in the studied peri-urban vegetation signify the ongoing biotic and abiotic pressure on the survival of different plant species at various growth stages. Besides, the predominance of plant species of rare and very rare occurrences (56.9%), IUCN Red-listed (59%) with a total of 84% native Indian origin species demonstrated the importance of the studied peri-urban vegetation and warrants for immediate conservation measures to protect it from further depletion.