Summary1. Both the phylogenetic structure and trait composition of flowering plant communities may be expected to change with altitude. In particular, floral colours are thought to vary with altitude because Hymenoptera typically decline in importance as pollinators while Diptera and Lepidoptera become more important at higher elevations. Thus, ecological filtering among elevation zones and competitive processes among co-occurring species within zones could influence the floral chromatic cues present at low and high elevations. 2. We collected data from 107 species of native flowering plants in the Himalaya Mountains of central Nepal over an elevation range of 900-4100 m, which includes habitat ranging from subtropical to subalpine within a relatively small geographical area. Using a phylogenetic framework, we asked whether and how flower colour diversity differed between species assemblages at lower and higher elevation, between monocots and eudicots, and between our sample from central Nepal and angiosperms from other regions of the world. 3. There was significant phylogenetic clustering in the communities as a result of monocots, particularly orchids, which were found overwhelmingly at lower elevations. Phylogenetic signal for floral colours indicated that related species had colours that were more disparate than expected under Brownian motion evolution. Floral colours were significantly more diverse in the higher elevation subalpine zone than in the subtropical zone. However, the chromatic cues at both elevations were consistent with the hue discrimination abilities of the trichromatic hymenopteran visual system. 4. Synthesis. Flower colour is not highly differentiated between subtropical and subalpine vegetation due to differences in the available orders of insect pollinators, or by the rate or direction of colour evolution in the lineages composing the two communities. Differences in colour diversity between zones may reflect differences in the ecologically available morphospace based on pollinator species richness and the constancy of their foraging behaviour. The chromatic signals present in Nepali species are similar to the signals found in insect-pollinated floras of other regions of the world.

Dactylorhiza hatagirea (D. Don) Soo, commonly known as "Panchaunle", is an important medicinal plant species distributed throughout the Himalaya region. The present work was conducted in order to assess its availability in natural habitats because of its medicinal properties, cultural significance and declining population density. The work focused primarily on its ecological features and conservation status. The density of D. hatagirea was found to be 2.18 individuals•m −2 with frequency and abundance being 81.81% and 2.67 individuals•m −2 , respectively. We considered grazing, trampling, number of cattle and distance to settlement as anthropogenic factors. While grazing and trampling were shown to have a significant, negative impact on population density, we observed no significant change in the number of the species with respect to number of cattle and distance to settlement. We conclude that the species is threatened and that anthropogenic factors have a significant effect on its habitation in the study area.

Dactylorhiza hatagirea is a terrestrial orchid listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and classified as threatened by International Union for Conservation of Nature (IUCN). It is endemic to the Hindu-Kush Himalayan region, distributed from Pakistan to China. The main threat to its existence is climate change and the associated change in the distribution of its suitable habitats to higher altitudes due to increasing temperature. It is therefore necessary to determine the habitats that are suitable for its survival and their expected distribution after the predicted changes in climate. To do this, we use Maxent modelling of the data for its 208 locations. We predict its distribution in 2050 and 2070 using four climate change models and two greenhouse gas concentration trajectories. This revealed severe losses of suitable habitat in Nepal, in which, under the worst scenario, there will be a 71–81% reduction the number of suitable locations for D. hatagirea by 2050 and 95–98% by 2070. Under the most favorable scenario, this reduction will be 65–85% by 2070. The intermediate greenhouse gas concentration trajectory surprisingly would result in a greater reduction by 2070 than the worst-case scenario. Our results provide important guidelines that local authorities interested in conserving this species could use to select areas that need to be protected now and in the future.

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