Amphibian functional diversity is related to high annual precipitation and low precipitation seasonality in the New World

Abstract

Aim We examined the geographical distribution of functional diversity for American amphibians and tested the relationship between functional diversity and environment. We also explored how the functional evenness of life‐history traits varies across biogeographical regions. Location Continental Americas. Methods We performed a trait classification based on an Eltonian approach and calculated functional diversity using Hill numbers, Shannon and Gini–Simpson indices. We tested the relationship between functional diversity and different axes of environmental variation by using a series of spatial autoregressive (SAR) models. Results Based on 212 different functional attributes for 2,776 species, we found that functional diversity has a latitudinal gradient consistent with that of species richness, regardless of the diversity index used. Evenness of functional diversity of amphibian assemblages varies depending on the region, but in general they are close to the maximum possible value. Areas with more functional richness relative to species richness are associated with high annual precipitation and low precipitation seasonality regardless of temperature; in contrast, areas with fewer functions than expected are associated with high aridity. Main conclusions The highest functional diversity is located in mountainous regions. Overall, functional diversity is positively correlated with humid environments with low precipitation seasonality and low aridity regardless of temperature. This is especially relevant for amphibians facing contemporary climate change because it suggests that future variation in rainfall patterns, but not in annual mean temperature, might interact with functional diversity to pose an imminent threat to amphibian functional diversity.

Geographical patterns and environmental drivers of functional diversity and trait space of amphibians of Europe

“…Several studies have explored the extent to which threat status and thus the extinction risk of amphibian populations depend on functional traits and communities structuring (e.g., Estrada et al, ; Sodhi et al, ). For such a functionally diverse (Ochoa‐Ochoa et al, ) taxonomic group, effective conservation planning must implement also research on functional traits and functional diversity to preserve ecosystem functioning (Becker, Loyola, Haddad, & Zamudio, ). Thus, understanding the relationship between functional diversity and the underlying environmental mechanisms forms a key action to predict the responses of amphibian communities to changes.…”

Synergistic impacts of global warming and thermohaline circulation collapse on amphibians

“…We used five observed bioclimatic variables from the Worldclim database to calibrate models that have been considered important for amphibian’s biology in previous studies 44 , 53 . These bioclimatic variables have a strong influence on species’ distributions and functional traits 44 , 48 , 53 , 54 and have been used to model species’ distributional areas both in current 44 and future climate change conditions 48 , 55 . The bioclimatic variables are Annual mean temperature (bio1), maximum temperature of the warmest month (bio5), minimum temperature of coldest month (bio6), annual precipitation (bio12), and precipitation seasonality (bio15).…”

Dimensions of amphibian alpha diversity in the New World

“…Functional diversity was estimated using the data from Ochoa‐Ochoa et al. (2019), which consists of nine traits for American Amphibians: (1) body size; (2) primary habitat type; (3) fertilization type; (4) reproductive cycle; (5) reproductive type; (6) spawn site; (7) presence/absence of larvae; (8) site of larvae development; and (9) presence/absence of parental care. This dataset contains information for 2,776 amphibian species occurring in Continental Americas (Frost, 2016).…”

“…sites with extreme environmental conditions as the case of desert or xeric habitats) there are strong constraints on lineages to diversify through trait functional space. For instance, Ochoa-Ochoa, Mejía-Domínguez, Velasco, Marske, and Rahbek (2019) found that amphibian species inhabiting arid habitats exhibited lower functional diversity than counterparts in habitats with higher humidity. We predict that in such areas FD values will be lower than expected based on PD or TD ( Figure 1a) as a response to habitat filtering mechanisms limiting the functional trait space under marginal environmental conditions when species do not meet the given environmental niche requirements (Götzenberger et al, 2012).…”

“…In this paper, we describe the geographical patterns of the multiple dimensions of alpha diversity for continental Amphibians from the New World. We previously found that the relationship between functional and taxonomic diversity is sensitive to precipitation, suggesting a key role for habitat filtering in shaping the geographic correlation and mismatches among the diversities (Ochoa-Ochoa et al, 2019). Here, we extend our analysis to phylogenetic diversity to gain further insight into how functional (FD), taxonomic (TD), and phylogenetic diversity (PD) are geographically correlated and where mismatches between these measures occur to gain better insight into the underlying processes behind the fascinating amphibian richness that exists in the Continental Americas.…”