The multidimensionality of the niche reveals functional diversity changes in benthic marine biotas across geological time

Abstract

Despite growing attention on the influence of functional diversity changes on ecosystem functioning, a palaeoecological perspective on the long-term dynamic of functional diversity, including mass extinction crises, is still lacking. Here, using a novel multidimensional functional framework and comprehensive null-models, we compare the functional structure of Cambrian, Silurian and modern benthic marine biotas. We demonstrate that, after controlling for increases in taxonomic diversity, functional richness increased incrementally between each time interval with benthic taxa filling progressively more functional space, combined with a significant functional dissimilarity between periods. The modern benthic biota functionally overlaps with fossil biotas but some modern taxa, especially large predators, have new trait combinations that may allow more functions to be performed. From a methodological perspective, these results illustrate the benefits of using multidimensional instead of lower dimensional functional frameworks when studying changes in functional diversity over space and time.

Functional biogeography of oceanic islands and the scaling of functional diversity in the Azores

“…Overlap between endemic, native, and exotic functional space at the archipelago scale was estimated following ref. 36. The multidimensional volume (i.e., convex hull) for each set of species was estimated, allowing quantification of the intersection between two (or more) species assemblages.…”

Fifty million years of herbivory on coral reefs: fossils, fish and functional innovations

“…The PCoA was based on a Gower's dissimilarity matrix [46] to accommodate the heterogeneous nature of the morphological data (a PCoA based on a Bray-Curtis dissimilarity matrix explained 5% more variance overall but was rejected owing to the statistical robustness of the Gower's matrix). The area of morphospace occupied by the Eocene and Recent surgeonfish assemblages was then calculated, and the nature of overlap was quantified [29,30].…”

“…(iii) Finally, new analytical approaches have provided a means of quantitatively examining changes in the functional morphospace occupied by species or assemblages through time, and the extent of overlap [29,30]. When combined, these advances provide us, for the first time, with the ability to examine the nature of herbivory in the past and to understand the extent to which important ecological processes on coral reefs may have changed through time.…”

Sediments and herbivory as sensitive indicators of coral reef degradation

“…The numbers of organisms present in an ecosystem, however, do not always relate to the functions they perform, even within functional groups (Nyström 2006, Graham et al 2013, Mouillot et al 2014. As such, more recent advances have advocated the use of multidimensional niche or trait-based metrics of fish or coral communities as measures of ecosystem state (Villéger et al 2011, Darling et al 2012, 2013, Mouillot et al 2013). However, regardless of the complexity of the metrics used, most studies still rely on measuring the abundance and/or diversity of organisms.…”