Flower colour and phylogeny along an altitudinal gradient in the Himalaya of Nepal

1. 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. 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...