Little noticed, but very important: The role of breeding sites formed by bamboos in maintaining the diversity of mosquitoes (Diptera: Culicidae) in the Atlantic Forest biome.

This study investigated the composition of mosquito species in different kinds of breeding sites in a tropical forest remnant of the Atlantic Forest and identified species of public health concern therein. Collections of immature forms of mosquitoes were carried out monthly at the Poço das Antas Biological Reserve in southeastern Brazil, between June 2014 and June 2015. Samples were collected from four types of breeding sites: bamboos, bromeliads, puddles, and a lake. A total of 1,182 specimens of mosquitoes belonging to 28 species and 13 genera were collected. Three species, Ad. squamipennis, An. neglectus, and Wy. arthrostigma represented 64.8% of the captured specimens. Only three species were found in more than one type of breeding site: Ps. ferox, An. triannulatus, and Tx. trichopygus. Two species of public health concern were found breeding in bamboo (Ae. aegypti and Ae. albopictus) and one in the lake (An. darlingi). Bamboo had the highest species richness, Shannon diversity, abundance of individuals and number of dominant species of all breeding sites. Similar Simpson diversity was obtained for bamboo and bromeliads, with higher values than those obtained for puddles and the lake. The significance of the four breeding sites, especially bamboos, is discussed in the context of controlling populations of sylvatic species of mosquitoes in Atlantic Forest areas.

Emergent properties of species-habitat networks in an insular forest landscape.

Deforestation and fragmentation are pervasive drivers of biodiversity loss, but how they scale up to entire landscapes remains poorly understood. Here, we apply species-habitat networks based on species co-occurrences to test the effects of insular fragmentation on multiple taxa-medium-large mammals, small nonvolant mammals, lizards, understory birds, frogs, dung beetles, orchid bees, and trees-across 22 forest islands and three continuous forest sites within a river-damming quasi-experimental landscape in Central Amazonia. Widespread, nonrandom local species extinctions were translated into highly nested networks of low connectance and modularity. Networks' robustness considering the sequential removal of large-to-small sites was generally low; between 5% (dung beetles) and 50% (orchid bees) of species persisted when retaining only <10 ha of islands. In turn, larger sites and body size were the main attributes structuring the networks. Our results raise the prospects that insular forest fragmentation results in simplified species-habitat networks, with distinct taxa persistence to habitat loss.

Assessing assemblage-wide mammal responses to different types of habitat modification in Amazonian forests.

Tropical forests are being heavily modified by varying intensities of land use ranging from structural degradation to complete conversion. While ecological responses of vertebrate assemblages to habitat modification are variable, such understanding is critical to appropriate conservation planning of anthropogenic landscapes. We assessed the responses of medium/large-bodied mammal assemblages to the ecological impacts of reduced impact logging, secondary regrowth, and eucalyptus and oil palm plantations in Eastern Brazilian Amazonia. We used within-landscape paired baseline-treatment comparisons to examine the impact of different types of habitat modification in relation to adjacent primary forest. We examined assemblage-wide metrics including the total number of species, number of primary forest species retained in modified habitats, abundance, species composition, and community integrity. We ranked all types of habitat modification along a gradient of assemblage-wide impact intensity, with oil palm and eucalyptus plantations exerting the greatest impact, followed by secondary regrowth, and selectively logging. Selectively-logged and secondary forests did not experience discernible biodiversity loss, except for the total number of primary forest species retained. Secondary forests further experienced pronounced species turnover, with loss of community integrity. Considering the biodiversity retention capacity of anthropogenic habitats, this study reinforces the landscape-scale importance of setting aside large preserved areas.

Avian extinctions induced by the oldest Amazonian hydropower mega dam: evidence from museum collections and sighting data spanning 172 years.

Hydroelectric dams represent an emergent threat to lowland tropical forest biodiversity. Despite the large number of operational, under-construction, and planned hydroelectric dams, their long-term effects on biodiversity loss are still poorly documented. Here, we investigate avian extinctions resulting from the Tucuruí Hydroelectric Reservoir (THR), the oldest Amazonian mega dam, which impounded the Tocantins River in 1984. Our avian inventory-based on several sampling methods (mist-netting, point-counts, boat census and qualitative surveys) during 280 days of fieldwork from 2005 to 2007-was combined with an exhaustive search of museum vouchers and digital online databases of citizen science from the lower Tocantins River to identify long-term trends in species persistence and extinction in the THR influence area. The regional avifauna was comprised of 479 species, 404 of which were recorded during our fieldwork. Based on recent and historical records spanning 172 years, we found evidence for likely extinctions at THR influence area for 53 (11.06%) species that have remained entirely unreported since 1984. We were further able to estimate extinction probabilities for 20 species; 15 species were considered to be extinct, including Psophia interjecta and Pyrilia vulturina that are red-listed by IUCN. Our study serves as a baseline for avifaunal monitoring in the THR influence area and shows that degree of habitat specialization is a key factor in determining species extinctions caused by nonrandom habitat loss from either inundation or deforestation. Avian species extinctions will most likely continue across the area affected by the reservoir as a direct impact of alluvial forest loss and ongoing habitat degradation of upland forests.