Niwot plant functional traits, 2008 - 2018.

Globally, human activities are altering environmental conditions through changes to disturbance regimes, climate, and primary productivity. Attempts to generalize changes in biodiversity in response to altered environmental conditions have had mixed success and the mechanisms that causes differences in responses are poorly understood. These contingent responses represent one of the largest obstacles to synthesis in community ecology and global change biology. Over the past decade, much progress has been made in resolving these ecological contingencies by shifting from a taxonomic perspective on community assembly and global change to a focus on functional traits. Functional traits are any morphological, physiological, or phenological characteristic of a species linked to fitness and have proven to be effective for understanding species interactions, biogeographic processes, and environmental change. Between 2008 and 2018, we measured plant height, specific leaf area, leaf size, chlorophyll content, stomatal conductance, leaf dry matter content, and leaf chemical composition (nitrogen, carbon, δ13C, δ15N) on 2689 individual plants from 141 species (not all traits on all individuals or species). These measurements were collected to capture intraspecific trait variation among the key habitat types on Niwot Ridge and to examine how species traits respond to global change in the ITEX experiment.