Differences in tree species diversity and soil nutrient status in a tropical sacred forest ecosystem on Niyamgiri hill range, Eastern Ghats, India

Abstract

We have quantitatively analyzed the tree species diversity with respect to soil nutrient status in three sites of a sacred forest ecosystem of Niyamgiri hill range, Eastern Ghats, India. Extensive field surveys and sampling were conducted in 3 sites of the hill range: Site 1 Pterocarpus dominated forest (PTF) (19A degrees 40'02.2aEuro(3) N and 83A degrees 21'23.1aEuro(3) E), Site 2 Mangifera dominated forest (MAF) (19A degrees 40'02.8aEuro(3) N and 83A degrees 21'40.8aEuro(3) E) and Site 3 Mixed forest (MIF) (19A degrees 36'47.1aEuro(3) N and 83A degrees 21'02.7aEuro(3) E). A total of 28 families, 42 genera, 46 tree species, and 286 individual trees were recorded on an area of 0.6 ha. Tree density varied between 470 and 490 individuals ha(-1) and average basal area between 3.16 and 10.04 m(2) ha(-1). Shannon Index (H') ranged from 2.34 to 4.53, Simpson's Index ranged from 0.07 to 0.09, and equitability Index ranged from 0.7 to 1.34. The number of individuals was highest in the girth at breast height (GBH) class of 50-70 cm. The soil nutrient status of the three forest types was related to tree species diversity. The soil pH value of the three sites reflected the slightly acidic nature of the area. Species diversity was positively correlated with organic carbon and phosphorus and negatively with nitrogen, EC and pH. The results of the current study may be helpful to further develop a conservation plan for tree species in tropical sacred forest ecosystems.