How pervasive is biotic homogenization in human‐modified tropical forest landscapes?

Land-cover change and ecosystem degradation may lead to biotic homogenization, yet our understanding of this phenomenon over large spatial scales and different biotic groups remains weak. We used a multi-taxa dataset from 335 sites and 36 heterogeneous landscapes in the Brazilian Amazon to examine the potential for landscape-scale processes to modulate the cumulative effects of local disturbances. Biotic homogenization was high in production areas but much less in disturbed and regenerating forests, where high levels of among-site and among-landscape β-diversity appeared to attenuate species loss at larger scales. We found consistently high levels of β-diversity among landscapes for all land cover classes, providing support for landscape-scale divergence in species composition. Our findings support concerns that β-diversity has been underestimated as a driver of biodiversity change and underscore the importance of maintaining a distributed network of reserves, including remaining areas of undisturbed primary forest, but also disturbed and regenerating forests, to conserve regional biota

A social and ecological assessment of tropical land uses at multiple scales: the Sustainable Amazon Network

Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazonia Sustentavel, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far.Keywords: Social–ecological systems, Tropical forests, Land use, Interdisciplinary research, Sustainability, Trade-off

Noteworthy ornithological records from the threatened campinas of the lower rio Tocantins, east Amazonian Brazil

Volume: 134Start Page: 247End Page: 25

Paragominas:a quantitative baseline inventory of an eastern Amazonian avifauna

We present the results of a five-month survey of the birds of Paragominas, Para, a municipality in eastern Brazilian Amazonia that lies within the Belem center of endemism. We recorded 440 species, sampling habitats across a gradient of disturbance, ranging from 'undisturbed' primary forest, through logged and burnt forest, patches of varyingly aged secondary forest, cattle pastures and intensive mechanized agriculture. Given the potential for species miss-identifications in avian inventories, we paid special attention to obtaining voucher documentation (photographs and sound recordings) and here provide a unique collection of publically-accessible digital vouchers for 418 species recorded (95% of the total). Many of the species reported here are poorly-known or represent notable range-extensions, and we present data on their status and distribution, both within the municipality and elsewhere in the Belem center of endemism. Notable amongst these include the first records for Para and Amazonia of Spotted Piculet (Picumnus pygmaeus), trans-Tocantins range-extensions for Large-headed Flatbill (Ramphotrigon megacephalum) and Yellow-shouldered Grosbeak (Parkerthraustes humeralis) and multiple observations of the threatened paraensis subspecies of Cinnamon-throated Woodcreeper (Dendrexetastes rufigula)

Idiosyncratic responses of Amazonian birds to primary forest disturbance

As humans continue to alter tropical landscapes across the world, it is important to understand what environmental factors help determine the persistence of biodiversity in modified ecosystems. Studies on well-known taxonomic groups can offer critical insights as to the fate of biodiversity in these modified systems. Here we investigated species-specific responses of 44 forest-associated bird species with different behavioural traits to forest disturbance in 171 transects distributed across 31 landscapes in two regions of the eastern Brazilian Amazon. We investigated patterns of species occurrence in primary forests varyingly disturbed by selective-logging and fire and examined the relative importance of local, landscape and historical environmental variables in determining species occurrences. Within undisturbed and disturbed primary forest transects, we found that distance to forest edge and the biomass of large trees were the most important predictors driving the occurrence of individual species. However, we also found considerable variation in species responses to different environmental variables as well as inter-regional variation in the responses of the same species to the same environmental variables. We advocate the utility of using species-level analyses to complement community-wide responses in order to uncover highly variable and species-specific responses to environmental change that remain so poorly understood

One hundred and thirty-five years of avifaunal surveys around Santarem, central Brazilian Amazon

We present an updated annotated avifaunal checklist for the Santarem region of central Para state, Brazil, an area that has one of the oldest histories of ornithological exploration in South America. We combine data from a five-month quantitative survey of the birds of the municipalities of Santarem and Belterra (east of the Tapajos River) between 2010 and 2011 with an exhaustive search of material in museum collections worldwide and digital vouchers deposited online. Our own survey sampled habitats across a gradient of disturbance ranging from 'undisturbed' primary forest, through logged and burnt forest, patches of secondary forest, cattle pastures and intensive mechanized agriculture. Given the potential for species misidentifications in avian inventories, we paid special attention to obtaining voucher documentation. Here we present a collection of publicly accessible digital vouchers for all of the new species, in addition to providing museum catalogue numbers for all old records. We added 24 species to the regional list, principally species associated with anthropogenic land-uses, but also including seven species restricted to primary forest habitats which were missed from both recent published inventories and over the course of two centuries of intensive collecting efforts. The regional list now stands at 583 species for which voucher documentation is available, with an additional 26 undocumented species. Many of the species reported here are poorly known or represent notable range extensions, and we present new data on their status and distribution

A social and ecological assessment of tropical land uses at multiple scales:the Sustainable Amazon Network

Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazonia Sustentavel, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far