Floral diversity, composition, and recruitment on the karstland of Baratang Island, India

Abstract

Karst-land vegetation was never before documented from India. Baratang limestone karst area, in tropical evergreen, semi-evergreen forests of the Andaman and Nicobar Islands, is the biggest and most dense cave complex with more than 175 underground caverns. We surveyed the limestone karst area of Baratang Island to understand vegetation diversity, composition and recruitment pattern. We encountered 90 tree species in the study area. Our result indicated dissimilarity in species diversity (F = 320.06; p < 0.001) and composition (P = 0.001; A = 0.031) among the trees and recruitment classes, where the diversity increased with the age of the vegetation classes (trees > saplings > seedlings). Tree diversity showed a positive correlation with the diversity of saplings and seedlings (Spearman's correlation coefficient: saplings =0. 25; p = 0.011; seedling =0.31; p = 0.002). We found that the dominant and co-dominant species in the karstic landscapes depicts exclusive vegetation patterns than the non-karstic areas. A better understanding of forest dynamics might prove a useful tool in the research of the fast-changing, sensitive karst ecosystems. Therefore, we strongly recommend further studies about karst-land vegetation in India.