Varronia curassavica, a subshrubby medicinal species associated with restinga in the Atlantic Forest, has been exploited by local people and the pharmaceutical industry. Indeed, restingas have experienced a continuous process of degradation, and thus, with species and ecosystem both at risk, efforts to support conservation actions are required. The present study aimed to evaluate aspects of V. curassavica reproductive biology. To accomplish this, morphological characterization was performed by monitoring flowering events. The availability of nectar and pollen, as well as the frequency and behavior of floral visitors and dispersers, was also evaluated. This species exhibits both heterostyly and protogyny. Anthesis is diurnal, and flowers last less than a day. The high number of flower and fruit abortions suggests that mechanisms, such as self-incompatibility intra-morphs and easily detached flowers, contribute to reduced fruit production. The high diversity of floral visitors indicate a generalist pollination syndrome. Diptera, Hymenoptera and Lepidoptera were the main pollinators, and nectar was the main resource sought by these insects. Fruits were dispersed by birds and ants. It can be concluded that the interaction of V. curassavica with several species is a key factor in its own survival and for maintaining the biological diversity of restinga.

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The mycorrhizal status of epiphytic, rupicolous, and terrestrial bromeliad species from the Brazilian Atlantic Rain Forest has been examined. Roots of 13 species of bromeliads were analyzed for the presence of mycorrhizal structures such as arbuscules, hyphae, and vesicles as well as other fungal structures. Rhizosphere soil was sampled to identify arbuscular mycorrhizal fungal (AMF) species associated only with terrestrial bromeliad species. Most specimens collected were epiphytic bromeliads in the genera Aechmea, Bilbergia, Nidularium, Tillandsia, and Vriesea. Differentiating structures of AMF were found in only three species of bromeliads. The pattern of mycorrhizal colonization was mainly internal, and external mycelium and arbuscules were observed only in the terrestrial Nidularium procerum. Root endophytes with dark brown septate mycelium, thin external hyphae, and Rhizoctonia-like sclerotia were also detected in some root segments. A total of ten spore morphotypes were recovered from the rhizosphere of N. procerum, with Acaulospora mellea, A. foveata, and Glomus sp. being the most common species recovered. Our study demonstrated that most of the epiphytic species are not associated with AMF. We attribute this mainly to the exposed bare root conditions found in epiphytic bromeliads.

Spatial genetic structure, population dynamics and spatial patterns in the distribution of Ocotea catharinensis Mez. from southern Brazil: implications for conservation

The grasslands conversion to forests is occurring globally and modifying the population dynamics of species. Here, we characterized the population dynamics of Podocarpus lambertii Klotzsch ex Endl. over four years in southern Brazilian forest–grassland mosaics. We asked (i) if the studied P. lambertii population would decrease or increase over time and (ii) what the role of forest patches is in the growth and recruitment of a P. lambertii population. Thus, we studied forest–grassland mosaics, stratified the population into four demographic classes, evaluated the population dynamics, and estimated the correlation between canopy cover and average number of individuals. All individuals of P. Lambertii occurred in forest patches. Density was high but decreased from seedlings to the reproductive stage. The population growth rate was λ = 1.025, and the recruitment of individuals was high and variable among years. The transition and mortality rates showed a pattern of reduction from seedlings to the reproductive stage. Mortality rate for seedlings and juveniles was low and concentrated at the smaller heights. The correlations between canopy cover and the average number of individuals were positive and significant. The ecological characteristics of this species and specific conditions provided by forest patches allow population growth and species conservation in the southern Brazilian forest–grassland mosaics.