Atlantic Forest Of South America Research Articles

Investigating the relative role of dispersal and demographic traits in predictive phylogeography

Many studies suggest that aside from environmental variables, such as topography and climate, species‐specific ecological traits are relevant to explain the geographic distribution of intraspecific genetic lineages. Here, we investigated whether and to what extent incorporating such traits systematically improves the accuracy of random forest models in predicting genetic differentiation among pairs of localities. We leveraged available ecological datasets for birds and tested the inclusion of two categories of ecological traits: dispersal‐related traits (i.e. morphology and foraging ecology) and demographic traits (such as species survival rate and generation length). We estimated genetic differentiation from published mitochondrial DNA sequences for 28 species of birds (1578 total genetic samples, 391 localities) in the Atlantic Forest of South America. Aside from the aforementioned ecological traits, we included geographic, topographic and climatic distances between localities as environmental predictors. We then created models using all available data to evaluate model uncertainty both across space and across the different categories of predictors. Finally, we investigated model uncertainty in predicting genetic differentiation individually for each species (a common challenge in conservation biology). Our results show that while environmental conditions are the most important predictors of genetic differentiation, model accuracy largely increases with the addition of ecological traits. Additionally, the inclusion of dispersal traits improves model accuracy to a larger extent than the inclusion of demographic traits. Similar results are observed in models for individual species, although model accuracy is highly variable. We conclude that ecological traits improve predictive models of genetic differentiation, refining our ability to predict phylogeographic patterns from existing data. Additionally, demographic traits may not be as informative as previously hypothesized. Finally, prediction of genetic differentiation for species with conservation concerns may require further careful assessment of the environmental and ecological variation within the species range.

Jaguars and wild pigs indicate protected area connectivity in the south-east Atlantic Forest (Brazil)

SummaryThe Atlantic Forest of South America has undergone major changes due to urban and agriculture/pasture extension, resulting in a highly fragmented biome. Protected areas, created to ensure the biodiversity conservation of this biome, need to be connected for long-term landscape integrity. We aimed to quantify connectivity among protected areas in the south-east Atlantic Forest using two species with different environmental requirements: a threatened species with high requirements, the jaguarPanthera onca; and an exotic species with low requirements, the wild pigSus scrofa. Our methods included expert opinion, andCircuitscapeand least-cost-path analyses. We hypothesized that the patchy and altered landscape would not support the connectivity of jaguars but would allow wild pigs to transit. In fact, we found connectivity for both species, but there were more connectivity opportunities for wild pigs. The connection between Serra do Mar (and Serra do Mar state park) and Serra da Mantiqueira (Mantiqueira Mosaic) is narrow but possible to traverse through some protected areas of sustainable use and private reserves, highlighting the importance of these to structural landscape connectivity for the studied species in this region. The same connectivity that allows the transit of the native jaguar with high environmental requirements also allows the invasive wild pig to move through the landscape, which is worrisome.

Snapshot of the Atlantic Forest canopy: surveying arboreal mammals in a biodiversity hotspot

AbstractThe Atlantic Forest of South America supports a rich terrestrial biodiversity but has been reduced to only a small extent of its original forest cover. It hosts a large number of endemic mammalian species but our knowledge of arboreal mammal ecology and conservation has been limited because of the challenges of observing arboreal species from ground level. Camera trapping has proven to be an effective tool in terrestrial mammal monitoring but the technique has rarely been used for arboreal species. For the first time in the Atlantic Forest, we obtained data on the arboreal mammal community using arboreal camera trapping, focusing on Caparaó National Park, Brazil. We placed 24 infrared camera traps in the forest canopy in seven areas within the Park, operating them continuously during January 2017–June 2019. During this period the camera traps accumulated 4,736 camera-days of footage and generated a total of 2,256 photographs and 30-s videos of vertebrates. The arboreal camera traps were able to detect arboreal mammals of a range of body sizes. The mammal assemblage comprised 15 identifiable species, including the Critically Endangered northern muriqui Brachyteles hypoxanthus and buffy-headed marmoset Callithrix flaviceps as well as other rare, nocturnal and inconspicuous species. We confirmed for the first time the occurrence of the thin-spined porcupine Chaetomys subspinosus in the Park. Species richness varied across survey areas and forest types. Our findings demonstrate the potential of arboreal camera trapping to inform conservation strategies.

Habitat stability shaped the demographic history of the Atlantic Forest endemic rodentEuryoryzomys russatus(Cricetidae: Sigmodontinae) during the Pleistocene

AbstractThe oryzomyine rodent Euryzoryzomys russatus is endemic to the Atlantic Forest of South America, where it inhabits mostly pristine humid forests. Previous phylogeographical studies performed with limited sample sizes indicated that rivers and climatic oscillations might have driven the diversification of this species. Here, we used a more comprehensive database to revisit the phylogeography and demographic history of E. russatus. Our phylogenetic inferences and haplotype network recovered four groups within E. russatus, each of which diversified between 0.33 and 0.60 Mya. These groups are mostly allopatric and are structured latitudinally along the Atlantic Forest. We did not detect any genetic break related to the major river drainages. Species distribution models recovered similar suitable areas for E. russatus in the present and past times, suggesting stability in the geographical range during the Pleistocene. The most pronounced change was the expansion of suitable areas onto the emerged continental shelf during the Last Glacial Maximum. Demographic analyses showed evidence of population expansion during periods of lowered seal levels, especially for the haplogroup associated with the Serra do Mar forest refuge. Therefore, our results failed to support the hypothesis of riverine barriers and suggest that the diversification of E. russatus is explained better by forest refugial processes.

Broad-scale gradients of resource utilization by phyllostomid bats in Atlantic Forest: patterns of dietary overlap, turnover and the efficacy of ecomorphological approaches.

Identifying mechanisms that promote coexistence at the local level is enigmatic for many organisms. Numerous studies have indirectly demonstrated that biotic interactions may not cause deterministic patterns reflective of the coexistence of interacting bat species. Nonetheless, demonstration of the partitioning of resources by phyllostomid bats by directly examining diet matrices may illuminate a mechanism of coexistence. I examined the dietary overlap of phyllostomid bats across 23 sites in the Atlantic Forest of South America. I also examined components of beta diversity (turnover and nestedness) of resources among species as well as the degree to which morphology can act as a surrogate for dietary similarity in each community. Bats exhibited high overlap. Nonetheless, dietary beta diversity was more related to turnover than nestedness of items suggesting substantive species-specific affinities. Niche breath and dietary overlap were positively related tothe number of species and the number of resources consumed in communities. Accordingly, changes in richness across Atlantic Forest may be facilitated by increases in resources available at the community level. There were positive, yet weak relationships between morphological and dietary distance. The relationship between morphology and diet was invariant relative to geography, species richness, number of dietary resources, average diet breadth and average dietary overlap indicating that in the Atlantic Forest morphology is a consistent surrogate of dietary relationships of species. Atlantic Forest is one of the most anthropogenically modified tropical forests in the world. This in combination with distinct climatic seasonality likely causes higher dietary overlap, weaker ecomorphological relationships and persistence of only the most general bat species.

Brazil’s Iguaçu National Park threatened by illegal activities: predicting consequences of proposed downgrading and road construction

The spectacularly biodiverse Atlantic Forest of South America has been reduced to fragmented remnants. The largest remaining inland fragment is protected by national parks on either side of the iconic Iguassu Falls on the border between Brazil and Argentina. Biodiversity in the parks has been under pressure from illegal activities such as commercial hunting, fishing and extraction of palm hearts. A proposed road through Brazil’s Iguaçu National Park now further threatens the area’s biodiversity by further dividing the forest fragment and by increasing access by illegal actors. Here we analyze spatial data on illegal activities and develop a niche-based model to predict the impact of the proposed Caminho-do-Colono road. The model shows the significant increases that this road would provoke in susceptibility to illegal activities such as fishing (median 0.009–0.101), palm-heart extraction (median 0.087–0.260) and poaching (median 0.324–0.334). The road proposal includes downgrading the protected status of a portion of the park, which reflects a worldwide pattern of downsizing, downgrading and degazetting protected areas that is particularly evident in Brazil.

Random placement models explain species richness and dissimilarity of frog assemblages within Atlantic Forest fragments.

Understanding the effects of random versus niche-based processes on biodiversity patterns is a central theme in ecology, and an important tool for predicting effects of habitat loss and fragmentation on biodiversity. We investigated the predictive power of random processes to explain species richness and species dissimilarity of amphibian assemblages in a fragmented tropical landscape of the Atlantic Forest of South America. We analyzed a large database of amphibian abundance and occupancy, sampled in 21 forest fragments ranging in size from 1.9 to 619ha. We compared observed species richness and species dissimilarity with the outcomes of two null (random placement) models: 1- the traditional Coleman's area-based model and 2- an abundance-based model (based on the number of individuals observed in each fragment). We applied these models for all species combined, and separately for forest-dependent and habitat-generalist species. The abundance-based model fitted the observed species richness data better than the area-based model for all species, forest-dependent species, and generalist species. The area-based and the abundance-based models were also able to significantly explain species dissimilarity for all species and for generalists, but not for forest dependent species. The traditional area-based model assigned too many individuals to large fragments, thus failing to accurately explain species richness within patches across the landscape. Although niche-based processes may be important to structuring the regional pool of species in fragmented landscapes, our results suggest that part of the variation in species richness and species dissimilarity can be successfully explained by random placement models, especially for generalist species. Evaluating which factors cause variation in the number of individuals among patches should be a focus in future studies aiming to understand biodiversity patterns in fragmented landscapes.

The Brazilian Torrent Frog Controls Its Paired Vocal Sacs Independently: Implications for Acoustic Parameters

Communication often mediates social interactions, including reproduction, defense, and competition. In anurans, vocal sacs are used in communication during interactions, and they may be controlled in a variety of ways. Hylodes heyeri is diurnal and inhabits streams in the Atlantic Forest of South America. Its vocalizations are complex, probably due to living in a noisy environment, and can involve either unilateral or bilateral inflation of their paired vocal sacs. Here, we analyze the acoustic parameters of territorial calls when the Brazilian Torrent frog inflates one or two vocal sacs in response to territorial calls from playback. Males using two vocal sacs emitted fewer notes per call, had longer note duration, and higher frequencies than males using one vocal sac. We conclude that the strategy of control of the paired vocal sacs in this genus may be related to the energy expenditure for vocalization, mainly in close interactions between individuals.

ATLANTIC ANTS: a data set of ants in Atlantic Forests of South America.

Ants, an ecologically successful and numerically dominant group of animals, play key ecological roles as soil engineers, predators, nutrient recyclers, and regulators of plant growth and reproduction in most terrestrial ecosystems. Further, ants are widely used as bioindicators of the ecological impact of land use. We gathered information of ant species in the Atlantic Forest of South America. The ATLANTIC ANTS data set, which is part of the ATLANTIC SERIES data papers, is a compilation of ant records from collections (18,713 records), unpublished data (29,651 records), and published sources (106,910 records; 1,059 references), including papers, theses, dissertations, and book chapters published from 1886 to 2020. In total, the data set contains 153,818 ant records from 7,636 study locations in the Atlantic Forest, representing 10 subfamilies, 99 genera, 1,114 ant species identified with updated taxonomic certainty, and 2,235 morphospecies codes. Our data set reflects the heterogeneity in ant records, which include ants sampled at the beginning of the taxonomic history of myrmecology (the 19th and 20th centuries) and more recent ant surveys designed to address specific questions in ecology and biology. The data set can be used by researchers to develop strategies to deal with different macroecological and region-wide questions, focusing on assemblages, species occurrences, and distribution patterns. Furthermore, the data can be used to assess the consequences of changes in land use in the Atlantic Forest on different ecological processes. No copyright restrictions apply to the use of this data set, but we request that authors cite this data paper when using these data in publications or teaching events.

Spatial predictors and species’ traits: evaluating what really matters for medium‐sized and large mammals in the Atlantic Forest, Brazil

Abstract Habitat loss and the conversion of natural environments to anthropogenic land uses are among the main drivers of biodiversity decline worldwide. The remaining habitats are inserted in highly modified landscapes, presenting contrasting patch and landscape features. Understanding species’ responses to these anthropogenic land‐use changes is essential for informing conservation planning. We evaluate which spatial predictors (measured at the patch and landscape scales) and species’ life‐history traits best predict the occurrence of medium‐sized and large mammals in forest fragments of the threatened Atlantic Forest of South America. We gathered occurrence data for 36 medium‐sized and large mammal species recorded by camera traps, distributed over 220 forest fragments spanning the entire Atlantic Forest biome. Species were classified according to their characteristics as follows: ‘hunted forest‐dependent’, ‘non‐hunted forest‐dependent’, and ‘generalist’ species. Further, each species’ occurrence was related to spatial predictors and life‐history trait variables. We revealed a severe defaunation of forest mammals occurring in most forest fragments in the Atlantic Forest. Landscapes containing large forest patches, low road density, and high human population density harboured high numbers of mammal species, including those exhibiting greater body mass. Nevertheless, mammal groups diverge in their sensitivity to landscape changes. Hunted forest‐dependent species mainly occurred in landscapes with lower edge density and numbers of patches and with less anthropogenic disturbance, while non‐hunted forest‐dependent species mainly occupied large forest fragments. Finally, generalist species also occurred in landscapes with low edge density and number of patches, but were more prevalent in landscapes with higher human population density. We stress the importance of maintaining large forest fragments, considering the effects of landscape configuration on conservation strategies, and reducing anthropogenic disturbances to ensure a greater persistence of mammal species in the Atlantic Forest.

Bird taxonomic and functional diversity in urban settlements within a forest biome vary with the landscape matrix

Urbanization represents one of the most striking threats to biodiversity due to habitat loss and fragmentation, particularly in forest biomes. The role of the surrounding matrix in maintaining native diversity in urban areas remains poorly studied. We compared taxonomic and functional bird diversity and dissimilarity between urban settlements (USs) and natural habitats (NHs) in the forest landscape matrix (FM) and agriculture landscape matrix (AM) of the Atlantic Forest of South America, and explored the relationships of species traits between USs and NHs. Birds were surveyed in five USs and five NHs in the FM, and four USs and three NHs in the AM using point counts. We used generalized least squares models to test for differences in diversities and dissimilarities between sites from the two landscapes, and the similarity percentage and fourth-corner analysis to determine the bird species and traits that contributed most to the differences between habitat types. Taxonomic and functional diversities were higher and dissimilarities were lower for US in the FM than for those in the AM. Species with urban and generalist traits occurred in all USs, but assemblages also included forest species in the FM. Urban areas should be managed to maintain a forest component, provided that it is necessary for forest bird species to breed successfully.

Forest cover influences chytrid infections in populations of Boana curupi, a threatened treefrog of south Brazil.

Complex interactions among hosts, pathogens, and the environment affect the vulnerability of amphibians to the emergence of infectious diseases such as chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd). Boana curupi is a forest-dwelling amphibian endemic to the southern Atlantic Forest of South America, a severely fragmented region. Here, we evaluated whether abiotic factors (including air and water temperature, relative air humidity, and landscape) are correlated with chytrid infection intensity and prevalence in B. curupi. We found individuals infected with Bd in all populations sampled. Prevalence ranged from 25-86%, and the infection burden ranged from 1 to over 130000 zoospore genomic equivalents (g.e.) (mean ± SD: 4913 ± 18081 g.e.). The infection load differed among populations and was influenced by forest cover at scales of 100, 500, and 1000 m, with the highest infection rates recorded in areas with a higher proportion of forest cover. Our results suggest that the fungus is widely distributed in the populations of B. curupi in southern Brazil. Population and disease monitoring are necessary to better understand the relationships between host, pathogen, and environment, especially when, as in the case of B. curupi, threatened species are involved.

Assessing the Extinction Probability of the Purple-winged Ground Dove, an Enigmatic Bamboo Specialist

The continued loss, fragmentation, and degradation of forest habitats are driving an extinction crisis for tropical and subtropical bird species. This loss is particularly acute in the Atlantic Forest of South America, where it is unclear whether several endemic bird species are extinct or extant. We collate and model spatiotemporal distributional data for one such “lost” species, the Purple-winged Ground DoveParaclaravis geoffroyi, a Critically Endangered endemic of the Atlantic Forest biome, which is nomadic and apparently dependent on masting bamboo stands. We compared its patterns of occurrence with that of a rare “control” forest pigeon, the Violaceous Quail-DoveGeotrygon violacea, which occurs in regional sympatry. We also solicit information from aviculturists who formerly kept the species. We find that the two species share a similar historical recording rate but can find no documentary evidence (i.e., specimens, photos, video, sound recordings) for the persistence of Purple-winged Ground Dove in the wild after the 1980s, despite periodic sighting records, and after which time citizen scientists frequently documented the control species in the wild. Assessments of the probability that the species is extant are sensitive to the method of analysis, and whether records lacking documentary evidence are considered credible. Analysis of the temporal sequence of past records reveals the extent of the historical range contraction of the Purple-winged Ground Dove, while our species distribution model highlights the geographic search priorities for field ornithologists hoping to rediscover the species—aided by the first recording of the species vocalizations which we obtained from interviews with aviculturists. Our interviews also revealed that the species persisted in captivity from the 1970s until the 1990s (up to 150 birds), until a law was passed obstructing captive breeding efforts by private individuals, putting an end to perhaps the best chance we had to save the species from extinction.

A revision of the subgenera Euhyboma Kolbe, 1893, Parahyboma Paulian, 1938, and Rubrohyboma Paulian, 1939 of Deltochilum Eschscholtz, 1822 (Coleoptera: Scarabaeidae: Scarabaeinae)

This paper provides a revision of the three smallest subgenera of Deltochilum, all endemic to the Atlantic Forest of South America. Deltochilum (Euhyboma) and D. (Rubrohyboma) are monospecific taxa, composed of D. brasiliense (Castelnau, 1840) and D. rubripenne (Gory, 1831), respectively, whereas D. (Parahyboma) is composed of two allopatric species, D. furcatum (Castelnau, 1840) and D. granulosum Paulian, 1933. Lectotypes for D. brasiliense and D. rubripenne are designated. Each species is analyzed as follows: a detailed literature review, a diagnosis, description, illustrations of key morphological characters, list of material examined, and geographic distribution. An improved identification key to the subgenera of Deltochilum is presented.

Life history and ecology might explain incongruent population structure in two co-distributed montane bird species of the Atlantic Forest

Comparative phylogeography is a powerful approach to investigate the role of historical and environmental processes in the evolution of biodiversity within a region. In this regard, comparative studies of species with similar habitat preferences are valuable to reduce the confounding influence of habitat association when interpreting phylogeographic patterns. In the Atlantic Forest of South America, phylogeographic studies of highland and lowland species have shown distinct population structure patterns so far, suggesting that such species have responded differently to Pleistocene glacial cycles. Herein, we performed a comparative analysis using molecular data and paleodistribution models of two Montane Atlantic Forest (MAF) co-distributed passerine birds with similar habitat requirements but with distinct life-history traits and ecologies: the frugivore lek-breeding Blue Manakin (Chiroxiphia caudata) and the insectivore and socially monogamous Drab-Breasted Bamboo Tyrant (Hemitriccus diops). We aimed to shed light on the role of contrasting life histories and ecologies onto the demography and population structure of MAF species. We sampled both species throughout most of their distribution range, sequenced a mitochondrial and a nuclear molecular marker, and used standard phylogeographic methods to investigate population structure and ecological niche modeling (ENM) to infer the species’ paleodistributions. Our analyses recovered a phylogeographic break in H. diops in the region of the Doce River, but no genetic structure in C. caudata. We also found higher differentiation among subpopulations within each lineage of H. diops than among subpopulations of C. caudata. We suggest that these discrepancies in population structure might be due to distinct life-history traits and their impact on gene flow and generation time. For example, while H. diops is an insectivore species, C. caudata is a frugivore and the latter ecological aspect likely selects for a higher dispersion distance. Additionally, because C. caudata is a lek-breeding species, it has a longer generation time than H. diops. These traits could hinder genetic differentiation when populations become geographically isolated. Nonetheless, both species showed some common biological features, such as signatures of synchronous population expansion and larger distribution ranges during the Last Glacial Maximum, possibly due to similar cold tolerance.

Does foraging competition drive plumage convergence in three look-alike Atlantic Forest woodpecker species?

Explaining the co-existence of sympatric and ecologically similar species is a central goal in ecology. In woodpeckers (Picidae), co-existence is frequently accompanied by plumage convergence. A particularly striking case concerns three woodpecker species in the Atlantic Forest of South America: Robust Woodpecker (Campephilus robustus), Lineated Woodpecker (Dryocopus lineatus) and Helmeted Woodpecker (Celeus galeatus), which show a remarkable degree of plumage similarity thought to result from convergence due to interspecific social dominance mimicry (ISDM). We studied the foraging ecology and interactions of these three species in old-growth forests and selectively logged forests to test the extent to which these species differ in various aspects of their foraging ecology, and we examined whether particular foraging requirements may help explain the association of the threatened Helmeted Woodpecker with mature forests. The species selected different tree species, tree diameters, foraging heights, decay states of trees and decay states of substrates, resulting in marked niche separation among the three species. Proportionally, the Robust Woodpecker chiselled more, Helmeted Woodpecker used more probing and Lineated Woodpecker used more hammering. Helmeted Woodpecker was the only species that included bamboos as foraging substrates, and it foraged more on dead wood than Lineated or Robust Woodpeckers, but mostly on small dead branches in live trees rather than standing dead trees. Foraging requirements are not the most likely factor explaining the association of Helmeted Woodpecker with mature forests. Limited resource and substrate overlap among the three woodpecker species, lack of interspecific interactions, and rarity of the Helmeted Woodpecker do not match predictions if these species were conforming to a mimicry complex under the hypothesis of ISDM. Instead, plumage convergence may aid in interactions with third species, or impart advantages in intraspecific competition.

Chiropteran metacommunity structure in the Atlantic Forest of South America

AbstractAimSpatial patterns of local species composition are shaped by dispersal ability. Here we examine the effects of dispersal ability on metacommunity structure of bats throughout the Atlantic Forest of South America considering differences among communities, functional groups and species regarding environmental, spatial and connectivity‐related drivers of composition. We also examined phylogenetic and ecological correlates, such as incidence (i.e. frequency of occurrence across sites) and wing morphology, of the degree to which species respond to spatial and environmental drivers.LocationAtlantic Forest of Argentina, Brazil and Paraguay.TaxonPhyllostomid bats.MethodsData from the Atlantic Bats dataset were compiled for 39 species at 120 sites. Variation was partitioned into pure environmental, pure space, pure connectivity, joint and unaccounted variation fractions. Redundancy analyses or linear regression determined amount of variation in variation fractions that was accounted for by phylogeny or ecological characteristics of species.ResultsThe metacommunity of Atlantic Forest phyllostomid bats was significantly structured by environmental, space and connectivity characteristics. Animalivore, nectarivores and sanguinivore species composition was significantly related only to connectivity. Frugivores exhibited structure that was significantly related to all three kinds of characteristics (pure environmental, pure spatial and pure connectivity) and similar to that of the overall metacommunity. Species‐specific responses to environmental, spatial and connectivity drivers were variable but exhibited strong affinities related to phylogeny and functional group. As incidence of a species increased, variation in distribution and abundance was more related to environmental characteristics. There was no significant relationship between forearm length and magnitude of the connectivity variation partition.Main ConclusionsMetacommunity structure of bats in the Atlantic Forest is complex and includes variation across multiple scales of ecological organization. Structure is strongly associated with phylogenetic, functional and distributional characteristics of species, with these, in turn, related to responses to spatial and environmental gradients in the Atlantic Forest.

Predictive sampling effort and species-area relationship models for estimating richness in fragmented landscapes.

Loss of habitat, specifically deforestation, is a major driver of biodiversity loss. Species-area relationship (SAR) models traditionally have been used for estimating species richness, species loss as a function of habitat loss, and extrapolation of richness for given areas. Sampling-species relationships (SSRs) are interrelated yet separate drivers for species richness estimates. Traditionally, however, SAR and SSR models have been used independently and not incorporated into a single approach. We developed and compared predictive models that incorporate sampling effort species-area relationships (SESARS) along the entire Atlantic Forest of South America, and then applied the best-fit model to estimate richness in forest remnants of Interior Atlantic Forest of eastern Paraguay. This framework was applied to non-volant small mammal assemblages that reflect different tolerances to forest loss and fragmentation. In order to account for differences in functionality we estimated small mammal richness of 1) the entire non-volant small mammal assemblage, including introduced species; 2) the native species forest assemblage; and 3) the forest-specialist assemblage, with the latter two assemblages being subsets of the entire assemblage. Finally, we geospatially modeled species richness for each of the three assemblages throughout eastern Paraguay to identify remnants with high species richness. We found that multiple regression power-law interaction-term models that only included area and the interactions of area and sampling as predictors, worked best for predicting species richness for the entire assemblage and the native species forest assemblage, while several traditional SAR models (logistic, power, exponential, and ratio) best described forest-specialist richness. Species richness was significantly different between assemblages. We identified obvious remnants with high species richness in eastern Paraguay, and these remnants often were geographically isolated. We also found relatively high predicted species richness (in relation to the entire range of predicted richness values) in several geographically-isolated, medium-size forest remnants that likely have not been considered as possible priority areas for conservation. These findings highlight the importance of using an empirical dataset, created using sources representing diverse sampling efforts, to develop robust predictive models. This approach is particularly important in geographic locations where field sampling is limited yet the geographic area is experiencing rapid and dramatic land cover changes. When combined, area and sampling are powerful modeling predictors for questions of biogeography, ecology, and conservation, especially when addressing habitat loss and fragmentation.

Can taxonomic and functional metrics explain variation in the ecological uniqueness of ecologically-associated animal groups in a modified rainforest?

The conservation of biodiversity requires adequate information about species and ecosystem attributes. The local contribution to β-diversity (LCBD) is a community composition-based metric of ecological uniqueness of sites. Here, we tested the capability of taxonomic and functional attributes of biological communities to explain variation in LCBD at a large spatial extent. We approached this idea using data on dung beetles and mammals (medium-to-large, small and volant) recorded across the Atlantic Forest of South America due to their millennial-scale evolutionary relationship (food providers and consumers). We related LCBD values to both taxonomic and functional metrics via beta regression. Our results revealed that taxonomic and functional features of assemblages can be used to predict variation in ecological uniqueness (LCBD). High LCBD values were associated with low species and functional richness for all animal groups. For dung beetles, high LCBD values were associated with low values of all functional metrics. For mammalian groups high ecological uniqueness was associated with low abundance, low Rao’s quadratic entropy, as well as high functional divergence, functional evenness, functional originality, and either low or high functional specialization. This implies that variation in ecological uniqueness can be explained by functional features at large spatial extents, although the type of functional metrics’ response of assemblages may be animal group specific. The potential of the LCBD metric to inform about both taxonomic and functional changes at large scales makes its use in conservation planning a highly promising approach.

Fragment configuration or environmental quality? Understanding what really matters for the conservation of native mammals in the Atlantic Forest of Argentina

The fragmentation of natural environments is one of the most important threats to biodiversity and involves changes in landscape configuration and habitat quality. The Atlantic Forest of South America has been highly fragmented, which creates concern for the conservation of its biodiversity. We evaluated the effects of forest loss and fragmentation on the terrestrial mammal assemblage of the Atlantic Forest of Misiones, Argentina. The area still contains large fragments and a forest cover >50%. We evaluated the effect of the configuration of the fragments (area, isolation) and the quality of the environment surrounding them (% of forest, land uses, poaching). We sampled mammal assemblages with camera-traps. We used generalized linear models, with the number of species in smaller forest fragments (49 stations) and the difference in their composition to that of the largest forest fragment (control situation; 53 stations) as response variables. Species richness in the fragments increased with the proportion of forest in their surroundings and decreased with the distance to population sources. The dissimilarity of the assemblages of smaller fragments to those of the largest fragment increased with forest disturbance and by the contrast of the land uses (e.g., annual crops) surrounding the fragments. We modeled and mapped these effects, which can be used as spatially explicit planning tools for the conservation of the mammal assemblage in this landscape. The effect of fragmentation on the mammal assemblage is mediated by both anthropic effects that affect the quality of the environment and by the spatial configuration of fragments in the landscape.