Erosion of global functional diversity across the tree of life

Abstract

Although one-quarter of plant and vertebrate species are threatened with extinction, little is known about the potential effect of extinctions on the global diversity of ecological strategies. Using trait and phylogenetic information for more than 75,000 species of vascular plants, mammals, birds, reptiles, amphibians, and freshwater fish, we characterized the global functional spectra of each of these groups. Mapping extinction risk within these spectra showed that larger species with slower pace of life are universally threatened. Simulated extinction scenarios exposed extensive internal reorganizations in the global functional spectra, which were larger than expected by chance for all groups, and particularly severe for mammals and amphibians. Considering the disproportionate importance of the largest species for ecological processes, our results emphasize the importance of actions to prevent the extinction of the megabiota.

Characterizing the spatial signal of environmental DNA in river systems using a community ecology approach

“…It might therefore be possible to compare historical and current data on fish faunas, and thus to follow biodiversity alterations experienced by freshwater faunas though current global changes as reported by (Su et al, 2021, p. 202). Moreover, freshwater fish are recognized as one of the most threatened taxa (Hughes, 2021) and the expected species extinction by the end of the century might deeply impact the functional properties of fish assemblages, as well as the services they provide to human societies (Carmona et al, 2021). Under this environmental urgency, eDNA inventories represent a fast and easy to handle fish inventory method providing equivalent and even more precise data than capture based methods.…”

Tetrapod diversity facets in jeopardy during the Anthropocene

“…Functional trait data for the different groups were collected using public databases from different sources. See 8 for a detailed description of the traits used in this study.…”

“…Data were retrieved from Amniote database 51 , which include traits for 4953 species of mammals, 6567 species of reptiles, and 9802 species of birds. Specifically, this database contains information of 29 life history traits, of which we selected a subset of traits with information available for at least 1000 species (see Table S1 in Carmona et al 8 for more details about traits and their completeness in each group). For mammals, eight traits were chosen: longevity (long, years), number of litters per year (ly), adult body mass (bm, g), litter size (ls, number of offspring), weaning length (wea, days), gestation length (gest, days), time to reach female maturity (fmat, days), and snout-vent length (svl, cm).…”

“…Later, we selected a set of functional traits characterizing tetrapod species from public databases 51,52 along with their phylogenies 20,40,53,54 . Due to the presence of missing values among traits, for each group we performed a phylogenetically informed trait imputation procedure followed by a sensitivity analysis to evaluate imputation performance following Carmona et al 8 , both using phylogenetic information that functional traits only. Briefly, for each taxonomic group we first compute the functional space using principal component analysis (PCA); we then artificially removed trait values in a reduced set of species which were later imputed with the complete database.…”

“…Humans drive patterns of biodiversity in the Anthropocene to the point that the world is facing the sixth mass extinction 1 , where nearly 1 million species are estimated to be threatened with extinction with severe consequences for ecosystem health and human wellbeing 2,3 . Biodiversity is a multidimensional metric 4 and species loss does not only entail a reduction in species richness, but potentially affect also the evolutionary history (phylogenetic diversity ̶ PD 5 ) and the functional structure (functional diversity ̶ FD 6 ) of natural communities 7,8 . While PD can provide information on how past dispersal events may have shaped current species assemblages 9 , FD depicts ecosystem functions and associated services than simple patterns of species richness and turnover might not completely disclose 10 .…”