Nesting patterns among Neotropical species assemblages: can reserves in urban areas be failing to protect anurans?

Morcegos urbanos de Guarulhos: alta riqueza de espécies e dominância de espécies ecologicamente flexíveis reveladas a partir de dados de monitoramento da raiva

RESUMO Urbanização afeta a composição e funções ecossistêmicas das comunidades de morcegos em várias regiões do planeta. Entretanto, este ainda é um tema pouco explorado no Neotrópico. No Brasil, embora poucas cidades apresentem inventários de quirópteros, órgãos municipais de saúde pública (e.g., Centro de Controle de Zoonoses) realizam a vigilância passiva dos morcegos infectados pelo vírus da raiva. Estas instituições fazem a identificação dos espécimes oriundos principalmente de áreas urbanas e coletam dados biológicos importantes para o manejo ambiental, controle populacional, ecologia e conservação das espécies. O presente estudo analisou os dados de recebimento de morcegos, de 2001 a 2017, oriundos da cidade de Guarulhos, comparando as taxas de recebimento, frequência, riqueza e dominância das espécies com estudos prévios conduzidos em cidades brasileiras. Os dados da vigilância em saúde pública demonstraram uma alta riqueza de espécies (n = 29), representadas por três famílias mais comuns em áreas urbanas brasileiras (Phyllostomidae, Molossidae e Vespertilionidae). Molossus molossus (Pallas, 1766), Glossophaga soricina (Pallas, 1766) e Myotis nigricans (Schinz, 1821) representaram a maioria (70%) dos dados da quiropterofauna de Guarulhos. Esta dominância pode estar relacionada com a flexibilidade da dieta dessas espécies (insetívoras e nectarívoras não obrigatórias) e abrigos diurnos em edificações, recursos estes altamente disponíveis nas cidades brasileiras. Assim, para mitigar os efeitos da urbanização sobre a rica quiropterofauna regional, recomenda-se que o planejamento ambiental das cidades considere suas diretrizes urbanísticas e florísticas como uma ferramenta ao manejo integrado da fauna silvestre e saúde pública, além de implantar estratégias para aumentar o potencial de conservação da biodiversidade nestes ambientes.

Functional traits explain amphibian distribution in the Brazilian Atlantic Forest

AIM

Species distributions are one of the most important ways to understand how communities interact through macroecological relationships. The functional abilities of a species, such as its plasticity in various environments, can determine its distribution, species richness and beta diversity patterns. In this study, we evaluate how functional traits influence the distribution of amphibians, and hypothesize which functional traits explain the current pattern of amphibian species composition.

LOCATION

Atlantic Forest, Brazil.

TAXON

Amphibia (Anura and Gymnophiona).

METHODS

Using potential distributions of Brazilian amphibians from Atlantic Forest based on their functional traits, we analysed the influence of biotic and abiotic factors on species richness, endemism (with permutation multivariate analysis) and beta diversity components (i.e. total, turnover and nestedness dissimilarities).

RESULTS

Environmental variables explained 59.5% of species richness, whereas functional traits explained 15.8% of species distribution (geographical species range) for Anuran and 88.8% for Gymnophiona. Body size had the strongest correlation with species distribution. Results showed that species with medium to large body size, and species that are adapted to living in open areas tended to disperse from west to east direction. Current forest changes directly affected beta diversity patterns (i.e. most species adapted to novel environments increase their ranges). Beta diversity partitioning between humid and dry forests showed decreased nestedness and increased turnover by increasing altitude in the south-eastern region of the Atlantic Forest.

MAIN CONCLUSIONS

Our study shows that functional traits directly influence the ability of the species to disperse. With the alterations of the natural environment, species more apt to these alterations have dispersed or increased their distribution, which consequently changes community structure. As a result, there are nested species distribution patterns and homogenization of amphibian species composition throughout the Brazilian Atlantic Forest.

Searching for Networks: Ecological Connectivity for Amphibians Under Climate Change

Ecological connectivity depends on key elements within the landscape, which can support ecological fluxes, species richness and long-term viability of a biological community. Landscape planning requires clear aims and quantitative approaches to identify which key elements can reinforce the spatial coherence of protected areas design. We aim to explore the probability of the ecological connectivity of forest remnants and amphibian species distributions for current and future climate scenarios across the Central Corridor of the Brazilian Atlantic Forest. Integrating amphibian conservation, climate change and ecological corridors, we design a landscape ranking based on graph and circuit theories. To identify the sensitivity of connected areas to climate-dependent changes, we use the Model for Interdisciplinary Research on Climate by means of simulations for 2080-2100, representing a moderated emission scenario within an optimistic context. Our findings indicate that more than 70% of forest connectivity loss by climate change may drastically reduce amphibian dispersal in this region. We show that high amphibian turnover rates tend to be greater in the north-eastern edges of the corridor across ensembles of forecasts. Our spatial analysis reveals a general pattern of low-conductance areas in landscape surface, yet with some well-connected patches suggesting potential ecological corridors. Atlantic Forest reserves are expected to be less effective in a near future. For improved conservation outcomes, we recommend some landscape paths with low resistance values across space and time. We highlight the importance of maintaining forest remnants in the southern Bahia region by drafting a blueprint for functional biodiversity corridors.

Influence of microhabitat on the richness of anuran species: a case study of different landscapes in the Atlantic Forest of southern Brazil

Environmental heterogeneity is a factor which can help explain the higher local species richness. The objective of this study was to test if richness and composition of anurans species are related to available microhabitats and landscape type of sampled sites. We assume that a higher number of microhabitats increase environmental heterogeneity and this, in turn, affects species richness of amphibians. We performed the study in the Mesophytic Semideciduous Forest, a vegetation type within Atlantic Forest Domain. Between October 2010 and February 2011, we sampled 23 water bodies located in the agricultural, forest, and urban landscapes. The species richness was determined using survey at breeding sites methodology, and the availability of microhabitats was estimated visually. Thirty-four anuran species belonging to 12 families were recorded. The species richness in water bodies ranged from two to 13 species. The highest species richness was recorded in environments with a higher number of microhabitats, while the species composition in water bodies was partially grouped according to the predominant landscape type that is agricultural, forest, forest edge or urban. Our results suggest that species use specific environments (e.g. landscapes, habitat and microhabitat) for their reproductive activities.