Bromeliads harbour a great diversity of fauna species. The epiphytic habit of bromeliads is subject to higher temperatures and higher incidence of light than is the epigeic habit, so we expected individuals of the Vriesea neoglutinosa species to differ in terms of the composition, richness and abundance of their fauna associated with different bromeliad habits. We carried out a study in a restinga area on Marambaia Island, Brazil. We collected 32 bromeliads, of which 16 were epigeic and 16 were epiphytic, and found a total of 1125 individual animals of 88 morphospecies. Arthropods stood out in the sample, among which 68.2% were insects. Aquatic fauna was richer in epigeic bromeliads, and terrestrial fauna was richer in epiphytic bromeliads. As expected, species composition was different for aquatic and terrestrial fauna. The heterogeneity of the restinga environment and differences in the development stages of the fauna may be factors that influence its composition. Both bromeliad habits sustain fauna with several trophic guilds that compose a complex food web and depend on the bromeliad environment. As different habits lead to different fauna types, both epigeic and epiphytic bromeliads play a role in the maintenance of local biodiversity and are important for macrofauna conservation in restingas.

The Hymnoptera order includes several flower-visiting insects (e.g. ants, bees, and wasps) and the coexistence of many different species in the same community can generate interspecific competition. Notwithstanding shared communities, research which evaluates how these taxonomic groups influence a whole community of flower-visiting Hymenoptera is lacking. Moreover, abiotic factors can also impact these floral visits, because each organism responds differently to climatic variations. The goal of this study is to evaluate abiotic factors, specifically relative air humidity and air temperature, which may be able to impact the number and the frequency of interactions between hymenopterans and flowers and to assess the composition and niche organization, by making use of interaction networks, of the entire community of flower-visiting Hymenoptera at the botanical garden of the Universidade Federal Rural do Rio de Janeiro. For the duration of a year, we took samples in that botanical garden, compartmentalizing the collections temporally in accordance with the time of the insects’ shift (morning or afternoon). We observed a positive influence of air temperature on the number of ant interactions and visits. It is also possible to observe that most of these interaction networks exhibited a nested and non-modular pattern and an average level of network specialization. In addition, bees stood out as the species with the highest frequency of visits and with the most generalist behavior. This study demonstrates how a botanical garden can sustain a diverse community of floral visiting Hymenoptera in an urban environment and why it consists in an important tool for biodiversity conservation.

Ants are able to interact with fruits and seeds that are not adapted for ant seed dispersal. In Brazil, several studies show interactions of ants with non-myrmecochorous diaspores; however, few of them have studied the structure of ant-fruit networks. The use of the network approach allows visualising multiple interactions between partners and how they are shaped by the community context. Our study aims to investigate ant-fruit networks as well as quantitative and qualitative dispersal components in a fragment of the Brazilian Atlantic Forest. We investigated the structure of interaction networks, diaspore removal rates, diaspore destination and dispersal distance over two years of observation. We constructed three interaction networks: dry season, rainy season and total, with the latter comprising the two formers. The diaspore removal rate, dispersal distance and diaspore destination experiments were performed for the plant species Miconia calvescens, Miconia prasina, Psychotria leiocarpa and Inga edulis. We recorded a large number of interactions, with diaspore cleaning being more frequent than removal. Ant-diaspore networks were nested, non-modular and little specialized. M. calvescens, M. prasina and I. edulis showed higher diaspore removal rates. Diaspore removal distances were the same among M. calvescens, M. prasina and I. edulis. In M. calvescens and I. edulis, the main diaspore destination was the ant’s nest. Our study shows that diaspore cleaning is the most common behavior in ant-diaspore interactions and there are no differences in the organization of interaction networks over the seasons. These results have implications for the future structure of plant communities, considering that a small part of the diaspores is removed, and that most of them are cleaned, favouring germination at the deposition site.

The destruction of forest habitats generates extremely fragmented areas and changes in vegetation structure. That changes the characteristics of microhabitats and the availability of resources and affects the diversity of animal species such as ants, which are a large group with an important ecological role. As ants forage on trees and shrubs, the vegetation structure can affect the presence of these organisms. Abiotic factors such as seasonality can also influence the diversity of the ant community. Based on that, this study aimed to investigate the distribution of the diversity of ant species that forage on plants in different seasonal periods. The study was carried out in eight secondary forest fragments of the Atlantic Forest. We used additive partitioning of diversity, partitioning of β diversity and canonical correspondence analysis to measure the effect of seasonality and vegetation structure on the distribution of ant species diversity. The rainy season positively influences the diversity of ants that forage on plants. Composition was affected by shrub leaf density in the rainy season and by tree circumference in the dry. Each fragment preserved a different pool of ant species, and the vegetation structure positively influenced ant diversity. These results highlight the importance of conserving the majority of forest fragments to better preserve the pool of ant species regionally.

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