Understanding how human impacts influence plant communities is particularly important for conservation planning since habitat destruction and fragmentation represents one of the greatest threats to biodiversity. One common method used to quantify plant community and habitat characteristics is floristic quality assessment, a system in which each species in a community is assigned a coefficient of conservatism (CC) value. These CC values are indications of species fidelity to high quality or remnant habitat; high CC values indicate conservative species found only in remnant habitat while low CC values indicate ruderal species. CC values for species are assigned based on expert opinion, so there is little quantitative evidence to back them. However, ecologists expect that conservative species should be functionally distinct from ruderal species. Here we investigated how functional trait measures align with CC determinations by comparing seed, leaf, and whole plant functional trait values with CC values of species from prairies in Wisconsin and glade grassland in the Ozarks.
Results/Conclusions
Comparisons between species functional traits and CC values indicated that leaf, seed, and plant height traits were related to CC. Specific leaf area, leaf N, and C:N ratio were significantly correlated with CC. These traits were related to the leaf economic spectrum, where “fast” leaves corresponded to low CC values (ruderal species) while “slow” leaves corresponded to high CC values (conservative species). Additionally, plant height and seed mass were related to CC values. These functional traits related to dispersal indicated that low CC species are taller and have smaller seeds, suggesting greater dispersal ability, consistent with their ruderal designation. In combination, functional traits had moderate power for predicting CC values. Relationships between functional trait measures and CC values indicate that CC determinations seem to be biologically meaningful method for community assessment that has underpinnings in plant life strategy characteristics.