Floristic Inventory and Quantitative Vegetation Analysis of Tropical Dry Deciduous

Tree diversity, species richness, basal area, population structure and distribution patterns were investigated in disturbed, moderately disturbed and undisturbed areas of the tropical dry deciduous forest of Piranmalai, Eastern Ghats in Tamil Nadu. The forest areas were selected based on the disturbance index. Six sites of 0.1ha area were established in the Piranmalai forest. Two sites, Nehru park (N.P) and Foot hill (F.H), were located close to the mining, quarrying and human settlement area, while two other sites, Vannar iruppu (V.I) and Alaguchokkan (A.C), are located in a selective felling area, and two others, Dhargha area (D.A) and Veerappan koil (V.K), are situated in a relatively undisturbed forest. These are 3 to 5 K.m apart in the forest disturbed stand (60 % disturbance index), Moderately Disturbed stand (30 % disturbance index), and Undisturbed stand (10 % disturbance index). Tree species richness varied along the disturbance gradient in different stands. The undisturbed stand showed the highest species richness (11 – 9). Species richness was lowest (5-4) in the Disturbed stand, while in the Moderately Disturbed stand the diversity was somewhat higher (8 – 7). The Shannon – Wiener index for tree species ranged from 1.33 to 2.184 in all the stands. The highest tree diversity was recorded in the undisturbed stand and the lowest in the Disturbed stand. The stands differed with respect to the tree species composition at the family and generic level