Biodiversity: The chasm between what we know and we need to know.

In this review I focus on what we need to know to make decisions relevant to land-use planning. I discuss four questions: What information about the distribution of biodiversity is available to decision makers? What sort of information is required at a local scale? Can we use species-distribution modeling to compensate for the lack of empirical information at larger scales? Can we use surrogates based on remote sensing for all our decisions? To be effective, biodiversity information needs to be based on standardized sampling with data made available during the initial planning phases of infrastructure projects, which are now based only on engineering or social considerations and occur several decades before construction starts. The RAPELD method is now being used in many environmental-impact studies to generate standardized data, but there is presently no mechanism to include biodiversity information in the initial phases of decision making, and this has unfavorable consequences for economic development and the environment. © 2019, Academia Brasileira de Ciencias. All rights reserved

The geometry of spatial analyses: Implications for conservation biologists

Most conservation biology is about the management of space and therefore requires spatial analyses. However, recent debates in the literature have focused on a limited range of issues related to spatial analyses that are not always of primary interest to conservation biologists, especially autocorrelation and spatial confounding. Explanations of how these analyses work, and what they do, are permeated with mathematical formulas and statistical concepts that are outside the experience of most working conservationists. Here, we describe the concepts behind these analyses using simple simulations to exemplify their main goals, functions and assumptions, and graphically illustrate how processes combine to generate common spatial patterns. Understanding these concepts will allow conservation biologists to make better decisions about the analyses most appropriate for their problems. © 2011 ABECO

Density and biomass estimates by removal for an amazonian crocodilian, paleosuchus palpebrosus

Direct counts of crocodilians are rarely feasible and it is difficult to meet the assumptions of mark-recapture methods for most species in most habitats. Catch-out experiments are also usually not logistically or morally justifiable because it would be necessary to destroy the habitat in order to be confident that most individuals had been captured. We took advantage of the draining and filling of a large area of flooded forest during the building of the Santo Antônio dam on the Madeira River to obtain accurate estimates of the density and biomass of Paleosuchus palpebrosus. The density, 28.4 non-hatchling individuals per km2 , is one of the highest reported for any crocodilian, except for species that are temporarily concentrated in small areas during dry-season drought. The biomass estimate of 63.15 kg∗km-2 is higher than that for most or even all mammalian carnivores in tropical forest. P. palpebrosus may be one of the World?s most abundant crocodilians. © 2016 Campos, Magnusson. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

The need for large-scale, integrated studies of biodiversity - the experience of the program for biodiversity research in Brazilian Amazonia

Brazilian Amazonia covers around 5 million km2. If we could sample it regularly, with one sample for each 1 degree cell (10,000 km2), we would need 500 sample sites. It is clear that financial costs limit the amplitude of biodiversity studies. As the area to be explored is so large, financial resources limited, and demands varied, a program on Amazonian biodiversity research must be cost-effective. Integrated and large-scale studies, using standardized protocols represent the only way to achieve these goals. In this review, we report on experience gathered at two model sites in Amazonia, Reserva Ducke and Alter do Chão, which were used to design the RAPELD system, which is the principle basis for the Inventory Component of the Program on Biodiversity Research (PPBio) of the Brazilian government (http://ppbio.inpa.gov.br). We address the following issues: 1) how scale, size, shape and distribution of sampling units affect the outcome of biodiversity studies, in terms of the estimation of biotic complementarity between sites, estimation of organismal abundance, and modeling of species distributions; 2) how different sampling needs, from different taxonomic groups, can be adjusted in integrated protocols; 3) how costs can be reduced through sub-sampling. Use of the method in other research sites in Amazonia is being conducted successfully, and a large network of standardized plots is being constructed (see http://ppbio.inpa.gov.br). We also show that other methodologies currently used in large-scale biodiversity studies can be integrated into the RAPELD design. © 2010 ABECO

Most species are not limited by an Amazonian river postulated to be a border between endemism areas

At broad scales in the Amazon, it is often hypothesized that species distributions are limited by geographical barriers, such as large rivers (river-barrier hypothesis). This hypothesis has been used to explain the spatial-distribution limits of species and to indicate endemism areas for several phylogenetic lineages. We tested the ability of the river-barrier hypothesis to explain patterns of species diversity and spatial-distribution limits for 1952 easily-detected species in 14 taxonomic groups that occur around the Madeira River, and our results indicate that the hypothesis that the Madeira River is the border between endemism areas and explains much of the diversity found in the region is inappropriate for >99% of species. This indicates that alternative hypotheses should be proposed to explain the limits of distributions of species around the Madeira River, as well as a revision of the criteria that are used to determine species-endemism areas. © 2018 The Author(s)

Extension of the geographical distribution of Schneider’s dwarf Caiman, Paleosuchus trigonatus (Schneider, 1801) (Crocodylia: Alligatoridae), in the Amazon–cerrado transition, Brazil

We present new records of occurrence of Schneider’s Dwarf Caiman, Paleosuchus trigonatus and extend its geographical distribution. Eight individuals were caught in the following locations: Sangue River, in the municipality of Campo Novo dos Parecis, Claro River and Marapi River, in the municipality of São José do Rio Claro, and tributaries of the Juruena River, in the state of Mato Grosso, Brazil. These records extend the geographical distribution of the species nearly 500 km south of the limit given in published range maps. © Campos et al

Spatial and temporal changes in bird assemblages in forest fragments in an eastern Amazonian savannah

We investigated the effects of forest fragmentation on bird assemblages in an Amazonian savannah landscape with forest fragments that have been isolated for more than 100 years. The study was conducted in areas surrounding the village of Alter do Chão (2°31'S, 55°00'W), Santarém, Brazil. Bird surveys and measurements of tree density were undertaken in 25 areas, with 19 plots in forest fragments of different sizes and six in an area of continuous forest. Data on forest-fragment size, perimeter, and isolation were obtained from a georeferenced satellite image. Variation in number of bird species recorded per plot was not related to vegetation structure (tree density). The number of bird species recorded per plot increased significantly only with fragment area, but was not influenced by fragment shape or degree of isolation, even when considering species from the savannah matrix in the analysis. Fragments had fewer rare species. Multivariate ordination analyses (multiple dimensional scaling, [MDS]) indicated that bird species composition changed along a gradient from small to large forest fragments and continuous-forest areas. In the Amazonian savannah landscapes of Alter do Chão, the organization and composition of bird assemblages in forest fragments are affected by local long-term forest-fragmentation processes. Differences in the number of bird species recorded per plot and assemblage composition between forest fragments and continuous forest were not influenced by forest structure, suggesting that the observed patterns in species composition result from the effects of fragmentation per se rather than from preexisting differences in vegetation structure between sites. Nevertheless, despite their long history of isolation, the forest fragments still preserve a large proportion (on average 80%) of the avifauna found in continuous-forest areas. The fragments at Alter do Chão are surrounded by natural (rather than planted) grassland, with many trees in the savannah matrix and the landscape has vast areas covered by forest, which may have helped to ameliorate the influences of forest fragmentation. © 2013 The Authors

Primeiro registro de Glironia venusta, Thomas, 1912 (Didelphimorphia) em Manaus, Amazonas, Brazil

A new record of a very rarely observed mammal, the bushy-tailed opossum, Glironia venusta (Didelphimorphia), was obtained for the Adolpho Ducke Forest Reserve, Manaus, Amazonas state, Brazil. Only 17 other records existed of this species, most from the 1980s. There were only three previous records of the species from Brazil (in the states of Pará, Amazonas and Rondônia). This new record supports the notion that G. venusta is a locally rare species throughout its range, but widely distributed in Brazilian Amazonia.Um indivíduo de Glironia venusta (Didelphimorphia), foi observado na Reserva Florestal Adolpho Ducke, Manaus, Amazonas, Brasil. Existem apenas 17 outros registros publicados desta espécie de marsupial, a maioria da década de 80. No Brasil, G. venusta havia sido registrada em três outras localidades, no Pará, Amazonas e Rondônia. Com este registro em uma das áreas mais intensivamente estudadas na Amazônia, ganha reforço a noção de que G. venusta é uma espécie rara localmente, mas de ampla distribuição na Amazônia brasileira

Distance to large rivers affects fish diversity patterns in highly dynamic streams of Central Amazonia

Longitudinal-zonation hypotheses generally predict gradual changes in fish composition from upstream to downstream due to changes in habitat conditions, but largely disregard downstream effects on upstream segments. Floodplains of large rivers represent areas of high connectivity during flood periods and can act as stable refuges in dry seasons, which may attenuate deterministic constraints imposed by local conditions on fish assemblages in surrounding habitats. In this study, we investigated the effects of proximity to large rivers on taxonomic- and functional-diversity patterns of stream-fish assemblages in an extensive region of Central Amazonia. We sampled 31 headwater-stream reaches in nine catchments in the Purus and Madeira Rivers interfluve between December 2014 and March 2015. Ninety seven fish species from seven orders and 19 families were captured. The results indicate that distance to large rivers is more important than distance among sites and local conditions in explaining functional and taxonomic diversity of stream-fish assemblages at large spatial scales. We also found a decrease in taxonomic and functional richness towards headwaters, mainly related to the loss of benthic and sedentary species along the distance gradient. These species may be favored by the proximity to refuge areas and high resource availability near the floodplain. In contrast, upstream assemblages were mainly occupied by small-sized, nektonic species with higher dispersal capacity, highly dependent of allochthonous resources. Downstream effects could be detected for many kilometers upstream in hydrographic catchments and this reinforces the crucial role of connectivity between fluvial habitats in maintenance of stream-fish diversity patterns in the region. © 2019 Stegmann et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited