Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023)

Understanding the role of individual species in high-diversity ecosystems is challenging. To make biodiversity tractable for study, many ecologists advocate dividing it into a smaller number of groups made up of species with similar traits, that respond in a similar way to key ecological processes, and that contribute to similar ecosystem functions. For example, dividing animals into herbivores and carnivores is a coarse trait-based classification, where the key functional trait is diet. However, functional groups can be defined much more finely than this by considering multiple traits. My main aim is to explore how well trait-based, functional perspectives reveal the processes underpinning species-rich ecosystems. My specific goals are to (1) clarify the link between species traits and the functions that species with these traits hypothetically serve in ecosystems, (2) test the extent to which species within the same functional group are really ecologically equivalent, and (3) see whether the conclusions we draw about management interventions (such as how fishing should be regulated) change depending on whether we focus on individual species or functional groups. I will use coral reefs as a model high-diversity ecosystem, focusing particularly on corals and fishes. My program will combine systematic reviews of published scientific literature with extensive field observations and experiments and simulation modeling. For example, to test how interchangeable species within a functional group are, I will assemble small coral communities in the field that consist of the same number of functional groups of corals, but that vary in the species that represent these functional groups. If species are interchangeable, we should see little difference between reefs in various ecosystem functions, such as biomass accumulation and herbivory. While using functional groupings seems to be a sensible way to deal with the great diversity of species-rich ecosystems, we must be careful that these trait-based methods do not hide ecological surprises that could lead to unsound management decisions. The proposed program will test key assumptions of the functional approach to try to define conditions under which this approach represents useful pragmatism or dangerous oversimplification. Although this program focuses on tropical reefs, there are direct applications to high-diversity, temperate ecosystems found on the east and west coasts of Canada.