Vegetation and Soil Dynamics : Insights from Prosopis juliflora- Intruded Areas in Hastinapur Wildlife Sanctuary

Abstract

Ecological study on plant diversity and soil characteristics of two contrasting sites (Prosopis juliflora-invaded and non-invaded) in Hastinapur Wildlife Sanctuary was undertaken to understand the structure of vegetation and soils and implication of exotic dominance in a dry tropical region of India. Seasonal floristic composition was recorded for one year through monthly visits. Phytosociological study of the two sites in each of three seasons was carried out by sampling a total of 120 quadrats (each 1mx1m, n= 20×3×2). Plant species density and abundance was estimated for both sites in each season. Seasonal surface soil (0–10 cm) samples were analyzed for soil pH, moisture content, organic C, and total N. Species occurrences and their relative abundance data were used to estimate alpha and beta diversity. A total of 76 plant species from 29 families were recorded (Malvaceae, Fabaceae and Asteraceae being top dominants). Maximum flora was recorded in rainy season at both sites, higher at non-invaded sites in all seasons. Beta diversity followed similar trend, higher in rainy season and at non-invaded than invaded sites, highest being 13.2 at non-invaded site in rainy season. Dominants changed with site and season. Vegetation patches were distinct in drier seasons compared to rainy months. Soil organic carbon, total nitrogen and C : N ratios were high at invaded sites compared to non-invaded sites except in summer season. While higher diversity and higher similarity amongst different sites in rainy season indicated a homogenization impact in Indian dry tropical regions, higher diversity at non-invaded site suggested implication of diversity-reducing impact of tree invader Prosopis juliflora.