Habit assessment and seed germination of Boswellia ovalifoliolata Bal. & Henry-An endemic, endangered, globally threatened medicinal tree toxon of Seshachalam hill range of Eastern Ghats of India

Abstract

Boswellia ovalifoliolata Bal & Henry is a narrow endemic tree species of Tirupati–Kadapa–Nallamalai hotspot. 25 years field observation leads to the present survey, which revealed the plant is restricted to specialized habitats on Tirumala forest at three regions in small isolated patches between 300-400m above MSL. 25x25 m quadrates of nine sites in three regions showed the highest frequency (40%) and density (26%) at lower altitudes. The plants are found in the localities where the soils with reddish brown loamy with rich granite complex. The trunk is a rich source of gum which is high medicinal value. Significant correlation was observed between girth of the tree trunk and gum production. Phenological data reveals that some plants in the fragmented patches are not flowering reg- ularly. Varieties of predators are reducing the seed production. Moreover the seeds are small and light weight and dispersed by wind and had no dormancy. The seeds had only 55% germination capacity, start losing viability on 15th day from maturation and 0% seed germination was observed 6-8 months after maturity. 7-10 days are re- quired for germination and seeds are sensitive to temperature. Following are the results reveled from the study
(1) the reduction in the population is due to ruthless collection of gum by making deep incisions on the trunk which causes the plants death. (2) invadination of seed predators, (3) lacking of seed dormancy and (4) less per- centage of seed germination and seedling vigour. Therefore, concrete measures should be taken to increase the population by rehabilitation of the species in identified potential areas to conserve the Boswellia ovalifoliolata for sustainable ecosystem.