Data for: Functional traits shape tree species distribution in the Himalayas

This data is the result of research entitled "Functional traits shape tree species distribution in the Himalayas". The research was carried out along a species-rich steep elevational gradient along the southern slopes of the Himalayas in central Nepal. To understand how traits shape the distribution of plant species along the elevational gradient, we selected 31 common tree species that partitioned the elevational gradient. To adequately describe species’ trait values and account for elevational trait variation, we sampled for each species 6 trees; three trees from the lower limits of their elevational distribution ranges and three trees from the upper limits. To assure that the traits are fully expressed, we sampled healthy-looking trees with sun-exposed crowns (crown illumination index ≥2.5, Clark and Clark, 1992). To reduce ontogenetic variation, we sampled adult trees with a stem diameter at breast height (DBH) between 10 and 30 cm. We selected 39 traits that are important for resource acquisition, use and conservation and play a key role in defence, metabolism, or adaptation to harsh environmental conditions (e.g. freezing, drought, and low nutrients availability). Traits were measured following standardized protocols (Pérez-Harguindeguy et al., 2013; Scholz et al., 2013; Zhang et al., 2016). We analysed how traits cluster into separate functions using a cluster analysis, and how traits and clusters associate into distinct plant strategies using a Principal Component Analysis. We found that multiple trade-offs in plant size, hydraulics, and light competitiveness shape species distribution along the elevational gradient. Along this extreme environmental gradient, stem and branch traits that integrate multiple plant organs and functions are better predictors of species’ elevational distributions than leaf traits.