Assessment of Roscoea population size in the Central Himalayas based on historical herbarium records and direct observation for the period 1913-2011
Authors: D. Mohandass, Mason J. Campbell, Jian-Li Zhao, Yong-Mei Xia, Babu Ram Paudel, Shankar Panthi, Qing-Jun Li
Pages: 10-18, March 15, 2016
The collection of plant specimens and their preservation within herbaria is invaluable in the documentation of temporal species change and the conservation of genetic plant resources. Historical plant collections enable an accurate determination of species geographical distribution at both the local and regional scale. In this study, we directly collected samples from Roscoea populations at various locations throughout Central Nepal and examined these along with those of the long-term historic herbarium data in order to assess their population size. A total of 136 plant collections were analyzed including 94 herbarium collections records (HR) covering 3 species, and 42 population collections of direct field observations (DFO) covering 5 species. Through our analysis of both the HR and DFO collections we found that: R. alpina and R. purpurea both possess a large population and wide geographic distribution, whilst, R. capitata and R. tumjensis both exhibit a narrow geographic range although the former has a moderate sized population and R. tumjensis a low population and restricted range. Finally, R. auriculata had a wide geographic distribution however its abundance was comparatively low. Our findings suggest that conservation of geographically widespread species should focus on landscape rather than site specific attributes. In addition, the rarest species could gain advantage through a species-specific conservation approach. We also suggest that comparing historical herbarium records with direct population sampling is a useful tool for plant biodiversity conservation.