Habitat mapping, population size and preventing extinction through improving the conservation status of Calamus nambariensis Becc. - an endemic and threatened cane of Assam, India

Abstract

Cane is one of the important forest products after timber, form an integral part of a rural and tribal population of many of the tropical countries of South East Asia, Africa and America. Calamus nambariensis Becc. has been recognized as endemic and threatened cane to the North East region of India. The plant is restricted to only two pockets of Assam with a poor population size. Therefore, conservation of this plant through proper scientific investigation is utmost necessary. The present investigation has as its objectives to study the distribution, estimation of population size, standardization of suitable micropropagation methods for reintroduction and reinforcement in suitable wild habitat as determined by ecological niche modelling (ENM) for the purposes of conservation. For improving the conservation status of the species, potential area and habitat for reintroduction was determined using maximum entropy (MaxEnt) distribution modelling algorithm. The population size in both the site was found to be very poor i.e., mean density, frequency of occurrence and abundance in relation to other associated species was 0.600, 29.26 and 2.307 in Nambor Reserve Forest whereas 0.526, 27.407 and 2.112 respectively in Gibbon Wildlife Sanctuary. Macropropagation of C. nambariensis was standardized here through seed germination which was found to be more efficient in terms of time and cost which revealed 87% germination in treated seeds, followed by 61% only for untreated seeds till 90days. It was also observed that seedlings in the hilly slope of Gibbon Wildlife Sanctuary (reinforcement) showed high survivability than that of the hilly slop of Lahorijan Reserve Forest (reintroduction). Further, survival rate was measured for 24months, which revealed significantly very high on an average of 97.85% in both the locations, while 1200 numbers of C. nambariensis plantlets were transferred to the field. The present study could change the population size of C. nambariensis in its natural habitat, proving effective means for preventing extinction and improving conservation status of the plant.