Atlantic Forest Of South America Research Articles

The evolutionary history of Eugenia sect. Phyllocalyx (Myrtaceae) corroborates historically stable areas in the southern Atlantic forests.

Eugenia sect. Phyllocalyx Nied. includes 14 species endemic to the Neotropics, mostly distributed in the Atlantic coastal forests of Brazil. Here the first comprehensive phylogenetic study of this group is presented, and this phylogeny is used as the basis to evaluate the recent infrageneric classification in Eugenia sensu lato (s.l.) to test the history of the evolution of traits in the group and test hypotheses associated with the history of this clade. A total of 42 taxa were sampled, of which 14 were Eugenia sect. Phyllocalyx for one nuclear (ribosomal internal transcribed spacer) and four plastid markers (psbA-trnH, rpl16, trnL-rpl32 and trnQ-rps16). The relationships were reconstructed based on Bayesian analysis and maximum likelihood. Additionally, ancestral area analysis and modelling methods were used to estimate species dispersal, comparing historically climatic stable (refuges) and unstable areas. Maximum likelihood and Bayesian inferences indicate that Eugenia sect. Phyllocalyx is paraphyletic and the two clades recovered are characterized by combinations of morphological characters. Phylogenetic relationships support a link between Cerrado and south-eastern species and a difference in the composition of species from north-eastern and south-eastern Atlantic forest. Refugia and stable areas identified within unstable areas suggest that these areas were important to maintain diversity in the Atlantic forest biodiversity hotspot. This study provides a robust phylogenetic framework to address important historical questions for Eugenia s.l. within an evolutionary context, supporting the need for better taxonomic study of one of the largest genera in the Neotropics. Furthermore, valuable insight is offered into diversification and biome shifts of plant species in the highly environmentally impacted Atlantic forest of South America. Evidence is presented that climate stability in the south-eastern Atlantic forest during the Quaternary contributed to the highest levels of plant diversity in this region that acted as a refugium.

A biodiversity hotspot losing its top predator: The challenge of jaguar conservation in the Atlantic Forest of South America.

The jaguar is the top predator of the Atlantic Forest (AF), which is a highly threatened biodiversity hotspot that occurs in Brazil, Paraguay and Argentina. By combining data sets from 14 research groups across the region, we determine the population status of the jaguar and propose a spatial prioritization for conservation actions. About 85% of the jaguar’s habitat in the AF has been lost and only 7% remains in good condition. Jaguars persist in around 2.8% of the region, and live in very low densities in most of the areas. The population of jaguars in the AF is probably lower than 300 individuals scattered in small sub-populations. We identified seven Jaguar Conservation Units (JCUs) and seven potential JCUs, and only three of these areas may have ≥50 individuals. A connectivity analysis shows that most of the JCUs are isolated. Habitat loss and fragmentation were the major causes for jaguar decline, but human induced mortality is the main threat for the remaining population. We classified areas according to their contribution to jaguar conservation and we recommend management actions for each of them. The methodology in this study could be used for conservation planning of other carnivore species.

Trichogoniinae, a new subtribe of Eupatorieae (Asteraceae)

We describe subtribe Trichogoniinae in tribe Eupatorieae to include three genera, Platypodanthera, Trichogonia, and Trichogoniopsis. Molecular phylogenetic results provide support for the taxonomic limits of the new subtribe. Morphological synapomorphies for the three genera include a pappus of plumose to subplumose bristles and cypselae with narrow stipitate bases. Subtribe Trichogoniinae is part of a clade whose generic and species diversity is mostly found in the Cerrado and Atlantic Forest of South America. A key to the genera of the subtribe is provided.

Seed Dispersal by Primates and Implications for the Conservation of a Biodiversity Hotspot, the Atlantic Forest of South America

Primates play a fundamental role as seed dispersers, particularly in tropical rainforests. Because defaunation and fragmentation are leading several primate species to local extinction, it is fundamental to understand the role of primates as effective seed dispersers. Here we present a systematic review of studies of seed dispersal by primates in a biodiversity hotspot, the Atlantic Forest of South America, to 1) highlight gaps in our knowledge, 2) determine species richness and proportion of seed species dispersed, and 3) test the relationship between primate body size and the size of dispersed species. Our review found 79 studies of the diet of six ecospecies (Callithrix, Leontopithecus, Callicebus, Sapajus, Alouatta, Brachyteles) but only 20 of these report information on seed dispersal, and none of these are on Callithrix or Callicebus. We found a strong bias in the distribution of species and regions, with most of the studies concentrated in southeastern Brazil. All ecospecies dispersed a large proportion of the seed species they handled (72.1–93.6%). Brachyteles dispersed the highest diversity of plants (N = 73), followed by Sapajus (N = 66), Leontopithecus (N = 49), and Alouatta (N = 26). Although we found no significant relationship between primate body size and the size of seeds dispersed, Brachyteles disperse a higher diversity of large-seeded species than smaller-bodied primates. These results suggest that the local extinction of large primate species may lead to dramatic changes in the plant community, as many large-seeded plants are inaccessible to smaller arboreal frugivores. We propose guidelines for future research on primate seed dispersal to enable the evaluation of seed dispersal effectiveness and to improve our understanding of the fundamental role of primates in this key ecosystem process.

Sexual dimorphism and allometry in the sphecophilous rove beetle Triacrus dilatus.

The rove beetle Triacrus dilatus is found in the Atlantic forest of South America and lives in the refuse piles of the paper wasp Agelaia vicina. Adults of T. dilatus are among the largest rove beetles, frequently measuring over 3 cm, and exhibit remarkable variation in body size. To examine sexual dimorphism and allometric relationships we measured the length of the left mandible, ocular distance and elytra. We were interested in determining if there are quantifiable differences between sexes, if there are major and minor forms within each sex and if males exhibit mandibular allometry. For all variables, a t-test was run to determine if there were significant differences between the sexes. Linear regressions were run to examine if there were significant relationships between the different measurements. A heterogeneity of slopes test was used to determine if there were significant differences between males and females. Our results indicated that males had significantly larger mandibles and ocular distances than females, but the overall body length was not significantly different between the sexes. Unlike most insects, both sexes showed positive linear allometric relationships for mandible length and head size (as measured by the ocular distance). We found no evidence of major and minor forms in either sex.

Phylogenetic analysis in Myrcia section Aulomyrcia and inferences on plant diversity in the Atlantic rainforest.

Myrcia section Aulomyrcia includes ∼120 species that are endemic to the Neotropics and disjunctly distributed in the moist Amazon and Atlantic coastal forests of Brazil. This paper presents the first comprehensive phylogenetic study of this group and this phylogeny is used as a basis to evaluate recent classification systems and to test alternative hypotheses associated with the history of this clade. Fifty-three taxa were sampled out of the 120 species currently recognized, plus 40 outgroup taxa, for one nuclear marker (ribosomal internal transcribed spacer) and four plastid markers (psbA-trnH, trnL-trnF, trnQ-rpS16 and ndhF). The relationships were reconstructed based on Bayesian and maximum likelihood analyses. Additionally, a likelihood approach, 'geographic state speciation and extinction', was used to estimate region-dependent rates of speciation, extinction and dispersal, comparing historically climatic stable areas (refugia) and unstable areas. Maximum likelihood and Bayesian inferences indicate that Myrcia and Marlierea are polyphyletic, and the internal groupings recovered are characterized by combinations of morphological characters. Phylogenetic relationships support a link between Amazonian and north-eastern species and between north-eastern and south-eastern species. Lower extinction rates within glacial refugia suggest that these areas were important in maintaining diversity in the Atlantic forest biodiversity hotspot. This study provides a robust phylogenetic framework to address important ecological questions for Myrcia s.l. within an evolutionary context, and supports the need to unite taxonomically the two traditional genera Myrcia and Marlierea in an expanded Myrcia s.l. Furthermore, this study offers valuable insights into the diversification of plant species in the highly impacted Atlantic forest of South America; evidence is presented that the lowest extinction rates are found inside refugia and that range expansion from unstable areas contributes to the highest levels of plant diversity in the Bahian refugium.

Dimensionality of community structure: phylogenetic, morphological and functional perspectives along biodiversity and environmental gradients

Biodiversity is a complex and multidimensional concept that characterizes variation of life on Earth. Nonetheless, most studies have examined only a few, if not just one, dimension in isolation. Herein we conduct analyses that explicitly incorporate correlations among multiple dimensions of biodiversity by characterizing morphological, phylogenetic, and functional structure of bat communities from Atlantic Forest of South America and examine degree of redundancy among these sets of descriptors. Second, we examine dimensionality (i.e. number of orthogonal dimensions) of community structure by quantitatively determining if these different sets of descriptors correspond to unique dimensions. We assess if dimensionality measured from empirical communities differs from that based on communities randomly assembled from a regional species pool. Finally, we examine whether different indices of community structure respond differently to environmental gradients spanning Atlantic Forest. We find that Atlantic Forest bat communities are highly variable in terms of morphological, phylogenetic, and functional structure. Different sets of community structure indices exhibited substantive correlations. Accordingly, dimensionality was lower than the set of six different descriptors or even the three different biological dimensions represented. Nonetheless, observed dimensionality was greater than that expected from a null model of assembly. Only abundance‐based indices of phylogenetic structure exhibited significant environmental gradients. Temperature seasonality was the strongest predictor of phylogenetic structure, with overdispersed communities characterizing more seasonal environments and underdispersed communities occurring in areas of lower variation in temperature. Dimensionality of community structure is low with phylogenetic structure exhibiting the strongest patterns, probably because phylogeny reflects many different ecological aspects of the phenotype that are not restricted to just one index of structure. Temperature seasonality is an important determinant of phylogenetic structure of bat communities in Atlantic Forest. This research helps us to better understand the factors underlying the distribution of biodiversity, which is increasingly important for endangered ecoregions such as Atlantic Forest.

Population genetic structure of the Atlantic Forest endemic Conopophaga lineata (Passeriformes: Conopophagidae) reveals a contact zone in the Atlantic Forest

The Rufous Gnateater, Conopophaga lineata, is a small insectivorous understory bird which is endemic to and widely distributed in the tropical and subtropical Atlantic forest of South America. Its distribution makes it ideally suited for testing two major hypotheses for the origin of biodiversity, namely, the riverine barrier and the forest refuge hypotheses. In this study, we sequenced mitochondrial (control region) and nuclear markers (intron 5 of the β-fibrinogen gene) for individuals distributed in the southern Atlantic forest and obtained a strong genetic structure with one clear discontinuity in northern Brazilian state of Sao Paulo. We consistently detected signals of demographic expansion for both markers, with estimates indicating that expansion started in the Late Pleistocene (250,000 years ago), suggesting that the forest refuge hypothesis potentially explains Rufous Gnateater’s diversification. We also found evidence of gene flow between populations from each side of this discontinuity, with a possible secondary contact zone occurring in the states of Minas Gerais, Sao Paulo, and Rio de Janeiro.

Nesting of the White-throated WoodcreeperXiphocolaptes albicollis

We report on the breeding biology of the White-throated Woodcreeper (Xiphocolaptes albicollis), a species endemic to the Atlantic forest of South America, based on 16 nesting attempts in 11 cavities (9 natural tree cavities and 2 nest boxes) in Misiones, northeastern Argentina. Natural cavities were 3.3–8.3 cm in diameter and 46–103 cm in depth, and generated by decay processes (not woodpeckers) at heights of 3–17 m in live trees 29–106 cm in diameter at breast height. White-throated Woodcreepers laid 2–4 eggs on alternate days, on a bed comprised of bark flakes, leaf fragments and seed pods. Incubation bouts (n = 3) were more than 1 hr 40 mins. Incubation lasted 17 days and the nestling period 18–22 days, shorter than the congeneric Great Rufous Woodcreeper (Xiphocolaptes major). Both adults brought nest material, incubated the eggs, fed the nestlings, and removed fecal sacs; however, we suspect that the male contributed more to fecal sac removal. Both adults roosted in the cavity a few nights before eggs were laid, but only one adult did so during the incubation and nestling periods. Nestlings were fed arthropods and small vertebrates at an average rate of 3 visits/hr with no change in delivery rate over the nestling period. Adults defended their nests from four bird species but shared one cavity with a roosting female Helmeted Woodpecker (Dryocopus galeatus) throughout their incubation period. We confirm that the White-throated Woodcreeper exhibits biparental care like the Great Rufous Woodcreeper, the Dendrocolaptes and the Lepidocolaptes, but in contrast to Sittasomus, Dendrocincla and Xiphorhynchus. We recommend studies with banded individuals to determine the relative contribution of each parent.

Gradients of Bat Diversity in Atlantic Forest of South America: Environmental Seasonality, Sampling Effort and Spatial Autocorrelation

AbstractTemperature seasonality has been proposed to be an important determinant of bat community structure in Atlantic Forest of South America and elsewhere. I characterized spatial and environmental patterns of species richness of phyllostomid bats in Atlantic Forest of South America and examined the degree to which temperature seasonality relative to other important environmental gradients was related to patterns of diversity across 60 heterogeneously sampled assemblages. I compared efficacy of different methods of accounting for inventory completeness (rarefaction, species estimation, minimum number of individuals and raw data) in characterizing gradients of bat diversity. I also compared levels of spatial autocorrelation generated by these methods and the degree to which such autocorrelation influenced results of regression analyses. Temperature seasonality was consistently the most important predictor of species richness across all methods of accounting for inventory completeness as well as between spatial and non‐spatial regression methods. Spatial autocorrelation of both species richness and regression residuals was lowest for species richness estimators and highest for data rarefied to the highest sample sizes. Strong and characteristic environmental gradients typifying Atlantic Forest of South America translate into coincident gradients of richness of bat assemblages. Although data were characterized by heterogeneous sampling efforts, relationships of species richness with seasonality of temperature were strong and easily detectable. Methods of accounting for inventory completeness improve assessment with species richness estimators performing better than rarefaction methods.

A multi-region assessment of tropical forest biodiversity in a human-modified world

The fate of much of the world’s terrestrial biodiversity is linked to the management of human-modified forest landscapes in the humid tropics. This Special Issue presents the first pan-tropical synthesis of research on the prospects for biodiversity in such systems, with eight individual regional summaries covering Mesoamerica, Amazonia, Atlantic forest of South America, West Africa, Madagascar, Western Ghats, Southeast Asia and Oceania. Two additional papers compare the state of conservation science in tropical forests with both temperate forests and savannah systems. This overview paper provides a comparative analysis of the threats and opportunities facing tropical forest biodiversity, thereby helping to identify the most pressing areas of future research and region-specific factors that contribute towards the effectiveness of individual conservation initiatives. While many of the threats facing tropical forest biodiversity are commonplace they vary markedly in their relative importance across different regions. There is a critical lack of comparable data to understand scale dependent processes, or the relative importance of varying geographic and historical contexts in determining present-day patterns. Conservation science has a key role to play in safeguarding the future of tropical forest biodiversity, but needs to become more effectively embedded in the context of real-world conservation challenges and opportunities. Significant progress can be achieved by improving the cost-effectiveness of research as well as the exchange of ideas and data amongst scientists working in different, often isolated parts of the world. We hope this special issue goes some way top achieving this exchange of knowledge.

Prospects for biodiversity conservation in the Atlantic Forest: Lessons from aging human-modified landscapes

Recent global assessments have shown the limited coverage of protected areas across tropical biotas, fuelling a growing interest in the potential conservation services provided by anthropogenic landscapes. Here we examine the geographic distribution of biological diversity in the Atlantic Forest of South America, synthesize the most conspicuous forest biodiversity responses to human disturbances, propose further conservation initiatives for this biota, and offer a range of general insights into the prospects of forest species persistence in human-modified tropical forest landscapes worldwide. At the biome scale, the most extensive pre-Columbian habitats across the Atlantic Forest ranged across elevations below 800 masl, which still concentrate most areas within the major centers of species endemism. Unfortunately, up to 88% of the original forest habitat has been lost, mainly across these low to intermediate elevations, whereas protected areas are clearly skewed towards high elevations above 1200 masl. At the landscape scale, most remaining Atlantic Forest cover is embedded within dynamic agro-mosaics including elements such as small forest fragments, early-to-late secondary forest patches and exotic tree monocultures. In this sort of aging or long-term modified landscapes, habitat fragmentation appears to effectively drive edge-dominated portions of forest fragments towards an early-successional system, greatly limiting the long-term persistence of forest-obligate and forest-dependent species. However, the extent to which forest habitats approach early-successional systems, thereby threatening the bulk of the Atlantic Forest biodiversity, depends on both past and present landscape configuration. Many elements of human-modified landscapes (e.g. patches of early-secondary forests and tree monocultures) may offer excellent conservation opportunities, but they cannot replace the conservation value of protected areas and hitherto unprotected large patches of old-growth forests. Finally, the biodiversity conservation services provided by anthropogenic landscapes across Atlantic Forest and other tropical forest regions can be significantly augmented by coupling biodiversity corridor initiatives with biota-scale attempts to plug existing gaps in the representativeness of protected areas.

Spatial patterns of bird community similarity: bird responses to landscape composition and configuration in the Atlantic forest

Studies dealing with community similarity are necessary to understand large scale ecological processes causing biodiversity loss and to improve landscape and regional planning. Here, we study landscape variables influencing patterns of community similarity in fragmented and continuous forest landscapes in the Atlantic forest of South America, isolating the effects of forest loss, fragmentation and patterns of land use. Using a grid design, we surveyed birds in 41 square cells of 100 km2 using the point count method. We used multivariate, regression analyses and lagged predictor autoregressive models to examine the relative influence of landscape variables on community similarity. Forest cover was the primary variable explaining patterns of bird community similarity. Similarity showed a sudden decline between 20 and 40% of forest cover. Patterns of land use had a second order effect; native bird communities were less affected by forest loss in landscapes dominated by tree plantations (the most suitable habitat for native species) than in landscapes dominated by annual crops or cattle pastures. The effects of fragmentation were inconclusive. The trade-off between local extinctions and the invasion of extra-regional species using recently created habitats is probably the mechanism generating the observed patterns of community similarity. Limiting forest loss to 30–40% of the landscape cover and improving the suitability of human-modified habitats will contribute to maintain the structure and composition of the native forest bird community in the Atlantic forest.

Specialization on Guadua Bamboo Seeds by Three Bird Species in the Atlantic Forest of Argentina

ABSTRACTMost bamboos are semelparous. Their synchronous masting events occur on a cycle of 3–120 yr and represent an extremely pulsed resource for granivorous birds. Although many bird species feed occasionally on bamboo seeds, there are constraints to specializing on such a fluctuating resource and few bird species are known to specialize on bamboo seeds. Three of these bird species are endemic to the Atlantic forest of South America: the purple‐winged ground‐dove Claravis godefrida, buff‐fronted seedeater Sporophila frontalis, and Temminck's seedeater Sporophila falcirostris. All three species are irregularly recorded in the province of Misiones, Argentina. We compared the temporal and spatial patterns of records of these birds in Misiones to masting events of the five common bamboos: yatevóGuadua trinii, takuaruzúGuadua chacoensis, takuapíMerostachys claussenii, pitinga Chusquea tenella, and takuarembóChusquea ramosissima. All bird records coincided with times and places where Guadua bamboos (G. trinii and G. chacoensis) were known or estimated to have seeds. None of the bird species occurred during masting events of Merostachys or Chusquea, unless Guadua was also masting. We discuss relevant ecological and morphological features of the birds that might bear on their association with Guadua bamboos and that might be key to their conservation.

The Atlantic Forest of South America: biodiversity status, threats and outlook

The Atlantic Forest of South America: biodiversity status, threats and outlook

The Atlantic Forest of South America: Biodiversity Status, Threats, and Outlook. State of the Hotspots. Edited by Carlos Galindo‐Leal and , Ibsen de Gusmão Câmara. Washington (DC): Island Press. $70.00 (hardcover); $35.00 (paper). xxi + 488 p; ill.; index. ISBN: 1–55963–988–1 (hc); 1–55963–989–X (pb). 2003.

<i>The Atlantic Forest of South America: Biodiversity Status, Threats, and Outlook. <i>State of the Hotspots.</i></i> <i>Edited by </i>Carlos Galindo‐Leal <i>and </i>, Ibsen de Gusmão Câmara. <i>Washington (DC): Island Press</i>. $70.00 (hardcover); $35.00 (paper). xxi + 488 p; ill.; index. ISBN: 1–55963–988–1 (hc); 1–55963–989–X (pb). 2003.

The Atlantic Forest of South America: biodiversity status, threats, and outlook

The Atlantic Forest of South America: biodiversity status, threats, and outlook

Deforestation and bird extinctions in the Atlantic forest

AbstractThe Atlantic forests of South America hold a great concentration of biodiversity, but most of this habitat has been destroyed. We therefore expect many species to become extinct, and yet no bird extinctions have conclusively been recorded. There could be three explanations for this. First, birds may be able to adapt to deforested landscapes. Second, many species may have become extinct before they were known to science. Third, there may be a time‐lag following deforestation before extinction occurs. We present the most complete list to date of the endemic birds of the Atlantic forests (124 forest‐dependent species), and then use the species–area relationship to predict how many species we expect to become extinct through deforestation (51 species i.e. 41%). We also count how many Atlantic forest endemic birds are independently considered ‘threatened’ with ‘a high risk of extinction in the wild in the medium‐term future’ (45 species i.e. 36%). We compare these totals and find that they are similar, suggesting that there is a time‐lag between deforestation and extinction. We go on to test the robustness of this result by varying the parameters used to make our predictions. The only parameter that varies enough to substantially weaken predictions based on deforestation is the habitat classification of Atlantic ‘forest’ birds. If we include species that can survive in secondary and non‐forest habitats then, unsurprisingly, we find that deforestation overestimates threat. Overall, not only does deforestation accurately predict threat to Atlantic forest endemic birds, but this result is robust enough to accommodate considerable variability within our data.

Deforestation and bird extinctions in the Atlantic forest

The Atlantic forests of South America hold a great concentration of biodiversity, but most of this habitat has been destroyed. We therefore expect many species to become extinct, and yet no bird extinctions have conclusively been recorded. There could be three explanations for this. First, birds may be able to adapt to deforested landscapes. Second, many species may have become extinct before they were known to science. Third, there may be a time-lag following deforestation before extinction occurs. We present the most complete list to date of the endemic birds of the Atlantic forests (124 forest-dependent species), and then use the species–area relationship to predict how many species we expect to become extinct through deforestation (51 species i.e. 41%). We also count how many Atlantic forest endemic birds are independently considered ‘threatened’ with ‘a high risk of extinction in the wild in the medium-term future’ (45 species i.e. 36%). We compare these totals and find that they are similar, suggesting that there is a time-lag between deforestation and extinction. We go on to test the robustness of this result by varying the parameters used to make our predictions. The only parameter that varies enough to substantially weaken predictions based on deforestation is the habitat classification of Atlantic ‘forest’ birds. If we include species that can survive in secondary and non-forest habitats then, unsurprisingly, we find that deforestation overestimates threat. Overall, not only does deforestation accurately predict threat to Atlantic forest endemic birds, but this result is robust enough to accommodate considerable variability within our data.