http://dspace.cus.ac.in/jspui/handle/1/6482 Mon, 13 Apr 2026 16:54:54 GMT 2026-04-13T16:54:54Z http://dspace.cus.ac.in/jspui/handle/1/6525 Title: Metapopulation modelling of threatened plants to assess conservation status and determine minimum viable population size Authors: Lyngdoh, Mark K.; Chettri, Arun; Adhikari, D.; Barik, S. K. Abstract: Use of metapopulation modelling in conservation of threatened plants has been demonstrated in this article taking Paris polyphylla Smith as an example. The metapopulation data collected from Sikkim Himalaya over a period of four years were analysed using RAMAS Metapop 5.0 software. Demographic projection, assessment of extinction probability, popu-lation viability analysis, and analysis of impact of dis-turbance on the metapopulation were undertaken. The metapopulation had 11 populations of which sev-en were in continuous forest (CF) and four were in forest fragments (FF). All the analyses were done in two model scenarios, viz. base-model (M1) represent-ing the disturbed condition, and alternate model (M2) representing the undisturbed condition for three dis-tinct layers of P. polyphylla populations, i.e. CF, FF in isolation, and collectively as metapopulation. The out-puts of the deterministic population models in respect of CF and FF populations revealed that both the populations had contribution of growth and survival of plants to such decline was greater than the fecun-dity in both the models. Stochastic simulations re-vealed an extinction risk of >10% in 100 years in M1 scenario, which put the species under vulnerable cate-gory. The extinction risk of metapopulation signifi-cantly varied between the two models (M1=0.85; M2=0.42), conforming the hypothesis that dis-turbance and forest fragmentation have detrimental effect on the persistence of P. polyphylla. Recovery of species was most promising when reproductive indi-viduals were introduced to the M2 model. Thus, both in-troduction of individuals in the field and protection of the populations with emphasis on the reproductive sub-set would result in achieving minimum viable popula-tion size or low threat status of the species. Mon, 01 Jan 2018 00:00:00 GMT http://dspace.cus.ac.in/jspui/handle/1/6525 2018-01-01T00:00:00Z http://dspace.cus.ac.in/jspui/handle/1/6524 Title: Inventory and characterization of newpopulations through ecological niche modelling improve threat assessment Authors: Adhikari, D.; Reshi, Z.; Datta, B. K.; Samant, S. S.; Chettri, A.; Upadhaya, K.; Shah, M. A.; Singh, P. P.; Tiwary, R.; Majumdar, K.; Pradhan, A.; Thakur, M. L.; Salam, N.; Zahoor, Z.; Mir, S. H.; Kaloo, Z. A.; Barik, S. K. Abstract: Categorization of species under different threat classes is a pre-requisite for planning, management and monitoring of any species conservation programme. However, data availability, particularly at the popula-tion level, has been a major bottleneck in the correct categorization of threatened species. Till date, threat assessments have been mostly based on expert opinion and/or herbarium records. The availability of primary data on distribution of species and their population at-tributes is limited in India because of inadequate field survey, which has been ascribed to resource con-straints and inaccessibility. In this study, we demon-strate that ecological niche modelling (ENM) can be an economical and effective tool to guide surveys overcoming the above two constraints leading to the discovery of new populations of threatened species. Such data lead to improved threat assessment and more accurate categorization. We selected 14 threat-ened plants comprising 5 trees (Acer hookeri Miq., Bhesa robusta (Roxb.) Ding Hou, Gynocardia odorataRoxb., Ilex venulosa Hook. f. and Lagerstroemia minu-ticarpa Debb. ex P.C. Kanjilal), 8 herbs (Angelica glauca Edgew., Aquilegia nivalis Falc. ex Jackson, Artemisia amygdalina DC., Begonia satrapis C.B. Clarke, Corydalis cashmeriana Royle, Dactylorhiza ha-tagirea (D. Don) Soo, Podophyllum hexandrum Royle, and Rheum australe D. Don), and 1 pteridophyte (An-giopteris evecta (Forst.) Hoffm.) having distribution range in North East India, Eastern and Western Hi-malaya, and Jammu and Kashmir. The study was car-ried out between 2012 and 2016. ENM-based survey led to the discovery and characterization of 348 new populations. The data so obtained helped in assigning conservation status to 10 species, which earlier were never classified due to data deficiency. Using the new population and distribution data of the remaining four species, only one was confirmed regarding its ex-isting status and two species were classified as ‘Criti-cally endangered’ instead of the present classification as ‘Endangered’. The fourth species was classified as ‘Critically endangered’ against the earlier category of ‘Least concerned’. Mon, 01 Jan 2018 00:00:00 GMT http://dspace.cus.ac.in/jspui/handle/1/6524 2018-01-01T00:00:00Z