Comparison of floristic diversity of evergreen forest inferred from different sampling approaches in the Eastern Ghats of Tamil Nadu, India

Floristic inventory and diversity studies are conducted using various sampling methods. The present study compared floristic diversity of an evergreen forest of Kolli Hill based on three sampling methods, viz. (a) ad hoc (AH) vegetation survey, (b) stratified random plot (SRP) and (c) bigger plot (BP). The evergreen forest area (2889.5 ha) was classified with IRS 1D LISS III satellite data and the evergreen area belonging to different reserve forests were subset. Floristic inventory with SRP was carried out on 0.1% of total evergreen area using 20 x 20 m plot. An earlier study done on the same locality was considered as the BP. The AH, SRP and BP recorded, 121, 91 and 78 tree species respectively. The mean tree densities were 547 and 478 trees ha(-1) and the mean basal areas were 46.74 and 43.6 m(2) ha(-1) in SRP and BP respectively. All the diversity indices calculated based on SRP with 3 ha sampling area and BP with 8 ha sampling area varied considerably.