Assessment of eco-diversity status of Homalomena aromatica (Spreng.) Schott and its habitat in tropical forest of Indian Eastern Himalaya

Abstract

Homalomena aromatica (Spreng.) Schott is one of the economically important plant species occurring in the North east and Eastern Himalayan region of India which received least attention in its ecological and conservation studies. The current study has been undertaken in the north eastern state of Arunachal Pradesh. The population, phytosociological status of its habitat, regeneration and species association of H. aromatica were worked out using standard ecological methods. Out of the 15 selected forest sites for survey, H. aromatica was found only in 9 sites. A total of 288 species representing 99 families are documented from the selected sites where Euphorbiaceae, Meliaceae, Araceae, Dipterocarpaceae and Poaceae are found dominant in all the 9 sites. Species diversity index (H′) of all the three habits i.e. the tree, shrub, and herb were found highest in Happy Valley site followed by Ganga Lake. A total of 219 individuals of H. aromatica recorded which were found confined within the altitudinal ranges of 350m-450m asl. The IVI (1.95 to 9.64) and Frequency % (5 to 12.5) range of H. aromatica found significantly low at all the survey sites. Pearson’s correlation analysis reveals that there is a positive relationship between the population size and the species diversity index, where shrub showed the strongest relationship (r(7)=0.900, P=0.001) followed by tree r(7)=0.736, P=0.024 and the herbs with weakest relationship (r(7)=0.39, P=0.269). The Chi-square test of association indicated significant association of 10 species with H. aromatica in the various sites where Alocasia acuminate (Aracaceae), Amomum sp. (Zingiberaceae) and Pteris sp. (Pteridaceae) showed highest association with higher Chi square value. The poor population status with average density of 3041.67/hectare and 8.89 frequency percentage as well the existing anthropogenic threats to the species recorded in the present study has warrants for its immediate conservation.