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Based on literature review and malacological collections, 168 native freshwater bivalve and five invasive species have been recorded for 52 hydrographic regions in South America. The higher species richness has been detected in the South Atlantic, Uruguay, Paraguay, and Amazon Brazilian hydrographic regions. Presence or absence data were analysed by Principal Coordinate for Phylogeny-Weighted. The lineage Veneroida was more representative in hydrographic regions that are poorer in species and located West of South America. The Mycetopodidae and Hyriidae lineages were predominant in regions that are richest in species toward the East of the continent. The distribution of invasive species Limnoperna fortunei is not related to species richness in different hydrographic regions there. The species richness and its distribution patterns are closely associated with the geological history of the continent. The hydrographic regions present distinct phylogenetic and species composition regardless of the level of richness. Therefore, not only should the richness be considered to be a criterion for prioritizing areas for conservation, but also the phylogenetic diversity of communities engaged in services and functional aspects relevant to ecosystem maintenance. A plan to the management of this fauna according to particular ecological characteristics and human uses of hydrographic regions is needed.

The rapid global decline of amphibian population is alarming because many occur for apparently unknown or enigmatic reasons, even inside protected areas (PAs). Some studies have predicted the effects of climate change on amphibians’ distribution and extinction, but the relationship and consequences of climate change to the phylogenetic structure of amphibian assemblages remain obscure. By applying robust techniques for ecological niche modeling and a cutting‐edge approach on community phylogenetics, here, we evaluate how climate change affects the geographical pattern of amphibian species richness and phylogenetic diversity in the Atlantic Forest Biodiversity Hotspot, Brazil, as well as how the phylogenetic composition of amphibian assemblages respond to climate change. We found that most species contracted their ranges and that such responses are clade specific. Basal amphibian clades (e.g. Gymnophiona and Pipidae) were positively affected by climate change, whereas late‐divergent clades (e.g. Cycloramphidae, Centrolenidae, Eleutherodactylidae, Microhylidae) were severely impacted. Identifying major changes in the phylogenetic pool represents a first step towards a better understanding of how assembly processes related to climate change will affect ecological communities. A deep analysis of the impacts of climate change not only on species, but also on the evolutionary relationships among species might foster the discussion on clade‐level conservation priorities for this imperiled fauna.

The Neotropics, Afrotropics and Madagascar have different histories which have influenced their respective patterns of diversity. Based on current knowledge of these histories, we developed the following predictions about the phylogenetic structure and composition of rainforest tree communities: (Hypothesis 1) isolation of Gondwanan biotas generated differences in phylogenetic composition among biogeographical regions; (H2) major Cenozoic extinction events led to lack of phylogenetic structure in Afrotropical and Malagasy communities; (H3) greater angiosperm diversification in the Neotropics led to greater phylogenetic clustering there than elsewhere; (H4) phylogenetic overdispersion is expected near the Andes due to the co-occurrence of magnoliids tracking conserved habitat preferences and recently diversified eudicot lineages. Using abundance data of tropical rainforest tree species from 94 communities in the Neotropics, Afrotropics and Madagascar, we computed net relatedness index (NRI) to assess local phylogenetic structure, i.e. phylogenetic clustering vs. overdispersion relative to regional species pools, and principal coordinates of phylogenetic structure (PCPS) to assess variation in phylogenetic composition across communities. We observed significant differences in phylogenetic composition among biogeographical regions (agreement with H1). Overall phylogenetic structure did not differ among biogeographical regions, but results indicated variation from Andes to Amazon. We found widespread phylogenetic randomness in most Afrotropical and all Malagasy communities (agreement with H2). Most of central Amazonian communities were phylogenetically random, although some communities presented phylogenetic clustering (partial agreement with H3). We observed phylogenetic overdispersion near the Andes (agreement with H4). We were able to identify how differences in lineage composition are related to local phylogenetic co-occurrences across biogeographical regions that have been undergoing different climatic and orographic histories during the past 100 Myr. We observed imprints of the history following Gondwana breakup on phylobetadiversity and local phylogenetic structure of rainforest tree communities in the Neotropics, Afrotropics and Madagascar.

Questions: Functional redundancy in assemblages may insure ecosystem processes after perturbation, potentially causing temporary or permanent local species extinctions. Yet, functional redundancy has only been inferred by indirect evidence or measured by methods that may not be the most appropriate. Here, we apply an existing method to measure functional redundancy, which is the fraction of species diversity not expressed by functional diversity, to assess whether functional redundancy affects community resilience after disturbance. Location: Subtropical grassland, south Brazil (30°05′46″S, 51°40′37″W). Method: Species traits and community composition were assessed in quadrats before grazing and after community recovery. Grazing intensity (G) was measured in each quadrat. We used traits linked to grazing intensity to define functional redundancy (FR) as the difference of Gini–Simpson index of species diversity (D) and Rao's quadratic entropy (Q). Also, with the same traits, we defined community functional stability (S) as the similarity between trait-based community composition before grazing and 47 and 180 d after grazing ending. Using path analysis we assessed different postulated causal models linking functional diversity (Q), functional redundancy (FR), grazing intensity (G) and community-weighted mean traits to community stability (S) under grazing. Results: Path analysis revealed the most valid causal model FR → S ← G, with a significant positive path coefficient for FR → S and a marginally significant negative one for S ← G. Since FR and G were independent in their covariation and in their effects on S, the model discriminated community resistance to grazing (the effect of G on S) from community resilience after grazing caused by functional redundancy (indicated by the effect of FR on S). Conclusion: We show that expressing functional redundancy mathematically is a useful tool for testing causal models linking diversity to community stability. The results support the conclusion that functional redundancy enhanced community resilience, therefore corroborating the insurance hypothesis.

We aimed to verify if frugivory in Tyrannidae birds (tyrants flycatchers) is influenced by environmental conditions, spatial filters, phylogenetic structure and food availability in Brazilian Araucaria forests. We used range maps to describe Tyrannidae species composition of 33 cells (0.25° X 0.25°) distributed along the Araucaria forest distribution range. Araucaria forests occur in southern and southeastern Brazil and northeastern Argentina, from 30°S to 20°S and at elevations above 500 m a.s.l. We compiled the feeding habits of each species from literature to calculate the proportion of frugivorous Tyrannidae in each cell. After that, we evaluated separately the influence of environmental descriptors, spatial filters (PCNM), phylogenetic structure (PCPS) and resource availability (proportion of zoochorous species) on the proportion of frugivorous birds using model selection based on AIC. Then we built a path model to evaluate the direct and indirect influences of different set of variables on frugivory. The path model showed that phylogenetic structure and spatial filters were the main factors determining the variation in frugivory in Araucaria forest sites. The environmental variable had no direct effect on frugivory, but presented an indirect effect via phylogenetic structure. Furthermore, zoochory was not selected as an important variable determining any other and was not included in the model. Our results showed that the influence of environment on frugivory by Tyrannidae birds was indirect via spatial and phylogenetic structure, that zoochory was not an important factor determining frugivory and that phylogenetic niche conservatism in feeding habits plays a role in determining the structure of Tyrannidae bird communities in Brazilian Araucaria forests.

Evidence of phylogenetic conservatism in plant ecological traits has accumulated over the past few years, suggesting an interplay between the distribution of phylogenetic clades and major environmental gradients. Nonetheless, determining what environmental factors underlie the distribution of phylogenetic lineages remains a challenge because environmental factors are correlated with spatial gradients where the latter might indicate some degree of dispersal limitation in phylogenetic pools. We analyzed the phylogenetic structure of plant assemblages across the Brazilian Araucaria forests and assessed how phylogenetic structure responds to environmental and spatial gradients. We compiled data on plant occurrence in 45 plots across the Araucaria forest biome. The phylogenetic structure of the plots was characterized using phylogenetic fuzzy-weighting followed by principal coordinates of phylogenetic structure (PCPS). We used distance-based redundancy analysis (db-RDA) to analyze the relationships between phylogenetic clades and environmental and spatial factors. Variation partitioning showed that the phylogenetic structure of Brazilian Araucaria forests was better explained by environment factors (altitude and annual mean temperature) than by space. Yet, spatially-structured environmental variation explained about one-third of total variation in the phylogenetic structure. Thus, the influence of spatial filters on the phylogenetic structure was more related to environmental gradients across the Brazilian Araucaria forest biome than to dispersal limitation of phylogenetic lineages. Furthermore, the influence of explanatory factors on the phylogenetic structure was concentrated in few nodes, the one splitting tree ferns from seed plants, and a second splitting malvids from other eurosids. Assessing the functional links between species distribution patterns and environmental gradients is not an easy task when we have to deal with large species pools. Identifying major phylogenetic gradients across an environmental and/or geographical range of interest can represent a first step towards a better understanding of general assembly processes in ecological communities.

Arthropods and land plants are the major macroscopic sources of biodiversity on the planet. Knowledge of the organization and specialization of plant-herbivore interactions, such as their roles in food webs is important for understanding the processes for maintaining biodiversity. A limited number of studies have examined herbivory through geological time. The most have analyzed localities from one restricted interval within a geological period, or a time transition such as the Paleocene-Eocene boundary interval. In the present study, we analyzed the frequency of herbivory and density of damage type (DT) from the Middle Devonian to the early Miocene. The data were compiled from literature sources and focused on studies that describe occurrences of leaves with DTs indicating herbivore consumption as a proportion of the total number of leaves analyzed. The data were standardized based on the DT categories in the Damage Type Guide, and the age of each locality was updated based on the most recent geochronological standard and expressed in millions of years. Temperature and geological age were the best descriptors of the variation in herbivory frequency, which tended to increase at higher temperatures. Two models were equivalent to explain DT density: the interaction between CO₂ levels and geological age, and O₂ levels and geological age had the same predictive power. The density of DT tended to increase with higher content of atmospheric CO₂ and O₂ compared to modern values. The frequency of herbivory and the density of DTs appear to be influenced by long-term atmospheric variables.

Questions: What is the magnitude of between-species trait variability (BSV) and within-species trait variability (WSV) of specific leaf area (SLA) in a sapling meta-community? To what extent do species turnover and WSV influence community-level mean trait responses to an environmental gradient and trait spread patterns across this gradient? What is the role of WSV for mean plant responses to environmental variation and niche partitioning in structuring sapling communities? Location: Forest patches within a native grassland matrix in southern Brazil. Methods: We recorded saplings in community plots across a canopy openness gradient in forest patches and described each of the 1129 individuals using SLA. First, we partitioned trait variation into BSV and WSV irrespective of co-occurrence in plots. Then, using the community data, we partitioned the total variation of community-weighted trait means (CWM) and Rao's functional diversity (FD) into components explained by canopy openness, species turnover and WSV. We also partitioned the effects of WSV between and within plots on FD. Finally, we explored the responses of CWM and FD to the gradient using the whole trait variability, only BSV or only WSV. Results: Specific leaf area presented a substantial proportion of variation within species (37%), although it varied more between species (63%). Species turnover and WSV explained 48% and 19% of the variation in CWM across the gradient, respectively. Species turnover and WSV explained 51% and 45% of the variation in FD across the gradient, respectively. SLA varied within species more along the gradient than within communities. Within-species variability enhanced shifts in CWM and FD across the gradient. Canopy openness significantly predicted CWM at all levels, and FD at all but the within-species level. Conclusions: Plastic responses of species mirrored the average response of communities to the environmental gradient. Within-species trait variability enhanced the mean plant responses to environmental variation as well as niche partitioning, and was especially important in enabling species to establish in a wider portion of the environmental gradient. Our study provides new evidence that population-level phenomena matter for community assembly.

We evaluated whether evolution is faster at ecotones as niche shifts may be needed to persist under unstable environment. We mapped diet evolution along the evolutionary history of 350 sigmodontine species. Mapping was used in three new tip‐based metrics of trait evolution – Transition Rates, Stasis Time, and Last Transition Time – which were spatialized at the assemblage level (aTR, aST, aTL). Assemblages were obtained by superimposing range maps on points located at core and ecotone of the 93 South American ecoregions. Using Linear Mixed Models, we tested whether ecotones have species with more changes from the ancestral diet (higher aTR), have maintained the current diet for a shorter time (lower aST), and have more recent transitions to the current diet (lower aLT) than cores. We found lower aTR, and higher aST and aLT at ecotones than at cores. Although ecotones are more heterogeneous, both environmentally and in relation to selection pressures they exert on organisms, ecotone species change little from the ancestral diet as generalist habits are necessary toward feeding in ephemeral environments. The need to incorporate phylogenetic uncertainty in tip‐based metrics was evident from large uncertainty detected. Our study integrates ecology and evolution by analyzing how fast trait evolution is across space. We explored whether evolution is faster at ecotone zones by developing three new tip‐based metrics — a species‐specific characterization of trait evolution — and spatializing them at the species‐assemblage level. We showed that evolution's speed — in terms of rates and time of diet transition — varies over space, with ecoregion ecotones having species with fewer transitions from the ancestral diet, longer stasis time of the current diet, and older transition to the current diet than ecoregion cores. Our research provides a formal link between macroecology and macroevolution, which is still rare in the ecological literature.

Functional traits mediate ecological responses of organisms to the environment, determining community structure. Community-weighted trait means (CWM) are often used to characterize communities by combining information on species traits and distribution. Relating CWM variation to environmental gradients allows for evaluating species sorting across the metacommunity, either based on correlation tests or ordinary least squares (OLS) models. Yet, it is not clear if phylogenetic signal in both traits and species distribution affect those analyses. On one hand, phylogenetic signal might indicate niche conservatism along clade evolution, reinforcing the environmental signal in trait assembly patterns. On the other hand, it might introduce phylogenetic autocorrelation to mean trait variation among communities. Under this latter scenario, phylogenetic signal might inflate type I error in analysis relating CWM variation to environmental gradients. We explore multiple ways phylogenetic history may influence analysis relating CWM to environmental gradients. We propose the concept of neutral trait diffusion, which predicts that for a functional trait x, CWM variation among local communities does not deviate from the expectation that x evolved according to a neutral evolutionary process. Based on this framework we introduce a graphical tool called neutral trait diffusion representation (NTDR) that allows for the evaluation of whether it is necessary to carry out phylogenetic correction in the trait prior to analyzing the association between CWM and environmental gradients. We illustrate the NTDR approach using simulated traits, phylogenies and metacommunities. We show that even under moderate phylogenetic signal in both the trait used to define CWM and species distribution across communities, OLS models relating CWM variation to environmental gradients lead to inflated type I error when testing the null hypothesis of no association between CWM and environmental gradient. To overcome this issue, we propose a phylogenetic correction for OLS models and evaluate its statistical performance (type I error and power). Phylogeny-corrected OLS models successfully control for type I error in analysis relating CWM variation to environmental gradients but may show decreased power. Combining the exploratory tool of NTDR and phylogenetic correction in traits, when necessary, guarantees more precise inferences about the environmental forces driving trait-mediated species sorting across metacommunities.