Light access and leaf trait variation within and among tree species across diverse mixtures within a common garden

Abstract

This dataset includes trait measurements for 2615 leaves of common temperate-boreal tree species alongside estimates of their light access. Trait values affect how plants function, with consequences that propagate through scales of ecological organization to affect ecosystem function. However, the pathway connecting trait expression to ecosystem function is complicated by feedbacks: trait expression may vary within species in response to community diversity, and trait expression also determines a community’s functional diversity. In this study, we quantify the extent to which light access – which past studies suggest affects trait expression and differs as a result of interactions among plants – differs consistently with community diversity and explains intraspecific trait variation in trees. In a common garden, trees of five angiosperm and seven gymnosperm species were planted to form 37 communities ranging widely in species and functional diversity whereby confounding environmental variation was minimized. We sampled leaves of each species to characterize intraspecific variation within crowns, among trees within communities, and among communities in three traits – leaf size, specific leaf area and nitrogen concentration – and estimated each leaf’s access to light.