Biology subjects

Cardoso, P.

Publications and source records attributed to Cardoso, P..

22 records · Page 2Linked to original sources

bioRxiv2020

Species traits predict extinction risk across the Tree of Life

SummaryBiodiversity is eroding at unprecedented rates due to human activity1. Species’ trajectories towards extinction are shaped by multiple factors, including life-history traits2 as well as human pressures3. Previous studies linking these factors to extinction risk have been narrow in their taxonomic and geographic scope4, thus limiting the ability for identifying global predictors. We studied the relation between 12 traits and the extinction risk of almost 900 species representing 15 groups across the tree of life (vertebrates, invertebrates and plants) at a global scale. We show that threatened species share narrow habitat breadth, poor dispersal ability, low fecundity, small altitudinal range, and are affected by a large human footprint. Other traits either show contrasting responses among groups (body size, offspring size, and change in human footprint), or relations were found for only a limited number of taxa (generation length, diet breadth, microhabitat). Our study suggests that in the absence of data on the precise distribution and population trends of species, traits can be used as predictors of extinction risk and thus help guide future research, monitoring and conservation efforts.Competing Interest StatementThe authors have declared no competing interest.View Full Text

ecology↗

bioRxiv2020

Functional diversity metrics using kernel density n-dimensional hypervolumes

O_LIThe use of n-dimensional hypervolumes in trait-based ecology is rapidly increasing. By representing the functional space of a species or community as a Hutchinsonian niche, the abstract Euclidean space defined by a set of independent axes corresponding to individuals or species traits, these multidimensional techniques show great potential for the advance of functional ecology theory. C_LIO_LIIn the panorama of existing methods for delineating multidimensional spaces, the R package hypervolume [Glob. Ecol. Biogeogr. (2014) 23:595-609] is currently the most used. However, functions for calculating the standard set of functional diversity (FD) indices--richness, divergence, and regularity--have not been developed within the hypervolume framework yet. This gap is delaying its full exploitation in functional ecology, meanwhile preventing the possibility to compare its performance with that of other methods. C_LIO_LIWe develop a set of functions to calculate FD indices based on n-dimensional hypervolumes, including alpha (richness), beta (and respective components), dispersion, evenness, contribution, and originality. Altogether, these indices provide a coherent framework to explore the primary mathematical components of FD within a multidimensional setting. These new functions can work either with hypervolume objects or raw data (species presence or abundance and their traits) as input data, and are versatile in terms of input parameters and options. C_LIO_LIThese functions are implemented within BAT (Biodiversity Assessment Tools), an R package for biodiversity assessments. As a coherent corpus of functional indices based on a common algorithm, it opens the possibility to fully explore the strengths of the Hutchinsonian niche concept in community ecology research. C_LI

ecology↗

bioRxiv2018

Decomposing the causes for niche differentiation between species using hypervolumes

1. Hutchinsons n-dimensional hypervolume concept holds a central role across different fields of ecology and evolution. The question of the amount of hyper-volume overlap and differentiation between species is of great interest to understand the processes that drive niche dynamics, competitive interactions and, ultimately, community assembly.\n\n2. A novel framework is proposed to decompose overall differentiation among hypervolumes into two distinct components: niche shifts and niche contraction / expansion processes. Niche shift corresponds to the replacement of space between the hypervolumes occupied by two species, whereas niche contraction / expansion processes correspond to net differences between the amount of space enclosed by each hypervolume.\n\n3. Hypervolumes were constructed for two Darwin finches, Geospiza conirostris and Geospiza magnirostris, using intraspecific trait data from Genovesa Island, where they live in sympatry. Results showed that significant niche shifts, not niche contraction, occurred between these species. This means that Geospiza conirostris occupied a different niche space and not a reduced space on Genovesa.\n\n4. The proposed framework allows disentangling different processes and understand the drivers of niche partitioning between coexisting species. Niche displacement due to competition can this way be separated from niche contraction due to specialization or expansion due to lower pressure on newly occupied ecological settings.

ecology↗

bioRxiv2018

A systematic review of the relation between species traits and extinction risk

Biodiversity is shrinking rapidly, and despite our efforts only a small part of it has been assessed for extinction risk. Identifying the traits that make species vulnerable might help us to predict the outcome for those less known. We gathered information on the relations of traits to extinction risk from 173 publications, across all taxa, spatial scales and biogeographical regions, in what we think it is the most comprehensive compilation to date. Vertebrates and the Palaearctic are the most studied taxon and region because of higher accumulation of data in these groups. Among the many traits that have been suggested to be good predictors, our meta-analyses were successful in identifying two as potentially useful in assessing risk for the lesser-known species: regardless of the taxon, species with small range and habitat breadth are more vulnerable to extinction. On the other hand, body size (the most studied trait) did not present a consistently positive or negative response. In line with recent research, we hypothesize that the relationship between body size and extinction risk is shaped by different aspects, namely body size is a proxy for different phenomena depending on the taxonomic group.

ecology↗