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Geoclimatic factors related to the uplift of the Himalaya and the Quaternary climatic oscillations influence the population genetic connectivity in the Himalaya–Hengduan Mountains (HHM) biodiversity hotspot. Therefore, to explore the relative roles played by these two factors, we examined the population dynamics and dispersal corridors of Incarvillea arguta (Royle) Royle incorporating ensemble species distribution modelling (SDM). Thirty‐seven populations were genotyped using plastid chloroplast DNA and low copy nuclear gene (ncpGS) sequences. Phylogeographic analysis was carried out to reveal the genetic structure and lineage differentiation. Ensemble SDMs were carried out for distributional change in the last glacial maximum, present, and future. Finally, the least cost path method was used to trace out possible dispersal corridors. The haplotypes were divided into four clades with strong geographical structure. The late Miocene origin of I. arguta in the western Himalaya ca. 7.92 Ma indicates lineage diversification related to the uplift of the HHM. The variability in habitat connectivity revealed by SDM is due to change in suitability since the Pleistocene. A putative dispersal corridor was detected along the drainage systems and river valleys, with strong support in the eastern Hengduan Mountains group. Our results support the signature of geoclimatic influence on population genetic connectivity of I. arguta in the HHM. We proposed that the major drainage systems might have assisted the rapid dispersal of isolated riverine plant species I. arguta in the HHM. The population genetic connectivity, using the fine‐tuned ensemble SDMs, enables scientists and policymakers to develop conservation strategies for the species gene pool in the HHM biodiversity hotspots.

Medicinal and aromatic plants (MAPs) have been identified as one of the potential high value commodities in Nepal with huge prospects for economic development. However, data about MAP consumption, volumes of trade and levels of demand are inadequate. In Nepal, there is a general lack of reliable trade data that constrains the estimation of total amount of MAPs in trade. This study aims to assess current trends in volume and value of MAP commodities exported from Nepal and identify the major destination countries. We mainly used formal trade data of Nepalese MAP products over the last 10 years (2005 to 2014) from the repository of UN COMTRADE database accessed via TRADE MAP. Results indicated that the export value of MAP products increased from USD 27.49 million in 2005 to USD 60.09 million in 2014 (mean for the last 10 years being USD 39.34 million) and this increment is primarily due to increase in price, as the trade volume follows decreasing trend over the same periods. The average annual export amount of Nepalese MAP products for the last 10 years has been calculated to be 13.23 thousand tons (range 10.77–20.25 thousand tons). The rise in export value of MAP products indicates increasing demand of MAPs globally. Nepalese MAP commodities were exported to almost 50 destinations. In terms of volume, India has been the major importer of MAP materials all these years. However, China stood top among the countries sharing high value to Nepalese MAP trade. The trade statistics show that, for the total trade value considering the MAP materials at broad category, the export of products (e.g., spices and flavors) other than listed in HS code 1211 should also be considered for appropriate valuation. Despite the decrease in trade amount, spices and flavors have fetched a gradually increasing price per unit volume which is apparent by the fact that these herbs have ever increasing market demand. Nepal can reap maximum benefit from growing international demand of MAPs given that Government impose strict check in borders to minimize the underestimation, train concerned authorities in proper identification of MAPs products and help to develop species-specific 8- and 10-digit HS Codes for proper documentation of imports and exports of MAPs products.Botanica Orientalis – Journal of Plant Science (2016) 10: 24–32

The genetic architecture within a species in the Himalaya-Hengduan Mountains (HHM) region was considered as the consolidated consequence of historical orogenesis and climatic oscillations. The visualization of dispersal corridors as the function of population genetic connectivity became crucial to elucidate the spatiotemporal dynamics of organisms. However, geodiversity and physical barriers created by paleo geo-climatic events acted vigorously to impact notable alterations in the phylogeographic pattern and dispersal corridors. Therefore, to achieve detailed phylogeography, locate dispersal corridors and estimate genetic connectivity, we integrated phylogeography with species distribution modelling and least cost path of Mirabilis himalaica (Edgew.) Heimerl in the HHM. We amplified four cpDNA regions (petL-psbE, rps16-trnK, rps16 intron, trnS-trnG), and a low copy nuclear gene (G3pdh) from 241 individuals of 29 populations. SAMOVA, genealogical relationships, and phylogenetic analysis revealed four spatially structured phylogroups for M. himalaica with the onset of diversification in late Pliocene (c. 3.64 Ma). No recent demographic growth was supported by results of neutrality tests, mismatch distribution analysis and Bayesian skyline plot. Paleo-distribution modelling revealed the range dynamics of M. himalaica to be highly sensitive to geo-climatic change with limited long-distance dispersal ability and potential evolutionary adaptation. Furthermore, river drainage systems, valleys and mountain gorges were identified as the corridors for population genetic connectivity among the populations. It is concluded that recent intense mountain uplift and subsequent climatic alterations including monsoonal changes since Pliocene or early Pleistocene formulated fragmented habitats and diverse ecology that governed the habitat connectivity, evolutionary and demographic

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Himalayan alder species are proven to be very useful in traditional as well as contemporary agroforestry practice. These nitrogen-fixing trees are also useful in the land restoration. Therefore, understanding the distribution of Himalayan alder and the potential zone for plantation is meaningful in the agroforestry sector. Suitable climatic zones of Alnus spp. were modelled in MaxEnt software using a subset of least correlated bioclimatic variables for current conditions (1950–2000), topographic variables (DEM derived) and Landuse Landcover (LULC) data. We generated several models and selected the best model against random models using ANOVA and t-test. The environmental variables that best explained the current distribution of the species were identified and used to project into the future. For future projections, ensemble scenarios of climate change projection derived from the results of 19 Earth System Models (ESM) were used. Our model revealed that the most favorable conditions for Alnus nepalensis are in central Nepal in the moist north-west facing slope, whereas for Alnus nitida they are in western Nepal. The major climatic factor that contributes to Alnus species distribution in Nepal appears to be precipitation during the warmest quarter for A. nepalensis and precipitation during the driest quarter for A. nitida. Future projections revealed changes in the probability distribution of these species, as well as where they need conservation and where they can be planted. Also, our model predicts that the distribution of Alnus spp. in hilly regions will remain unchanged, and therefore may represent sites that can be used to revitalize traditional agroforestry systems and extract source material for land restoration.

The prolonged interplay between orographic and climatic changes creates biogeographic barriers, resulting in the allopatric differentiation of plants in the Himalaya–Hengduan Mountains. Such consequences have led us to investigate the long-term Neogene–Quaternary geo-climatic history of the Eastern Himalaya–Hengduan Mountains. Narrowly distributed populations of Koenigia forrestii were sampled (ten populations, 97 individuals) and analysed for their genetic architecture, including phylogenetic reconstruction (based on plastome and plastid DNA/nuclear regions), molecular dating and demography, in combination with niche dynamics. We estimated that K. forrestii (stem age: 11.39 Mya) diverged into three non-overlapping distributed lineages during the Neogene–Quaternary periods (5.84–2.57 Mya), with Eastern Himalaya (EHa) being the first and most diverse lineage. ‘Isolation by environment’ revealed the existence of genetic structures that were significantly affected by the disparate environment. The presence of demographic events is well supported by the Bayesian skyline plot, indicating recent demographic expansion. Hence, lineage divergence and differentiation were mainly triggered by the heterogeneous environment associated with the biogeographic barriers due to the Tsangpo-Brahmaputra Grand Canyon, Mekong-Salween Divide and local mountain systems. Nevertheless, niche shift and local adaptation are the keys to determining the genetic architecture, demographic dynamics and diversification history of K. forrestii.