Amazonian Sites Research Articles

Evapotranspiration of deforested areas in central and southwestern Amazonia

Considering the high rates of evapotranspiration of Amazonian forests, understanding the impacts of deforestation on water loss rates is important for assessing those impacts on a regional and global scale. This paper quantifies evapotranspiration rates in two different pasture sites in Amazonia and evaluates the differences between the sites. In both places, measured evapotranspiration varies seasonally, decreasing during the dry season. The decrease is higher at the southwestern Amazonia site, while at the central Amazonia site, the decrease is less pronounced. During the dry season, average values of evapotranspiration are around 2.2 ± 0.6 mm day−1 in central Amazonia and 2.4 ± 0.6 mm day−1 in southwestern Amazonia, while during the wet season, those values are 2.1 ± 0.6 mm day−1 in central Amazonia and 3.5 ± 0.8 mm day−1 in southwestern Amazonia. On an annual basis, the pasture in southwestern Amazonia has higher evapotranspiration than in central Amazonia. We conclude that the main reason for this difference is the lower available energy in the wet season at the central Amazonian site, combined with a lower leaf area index at this site during the whole year. Still, the evapotranspiration is significantly controlled by the vegetation, which is well coupled with the local moisture conditions in the dry season.

Spatial tools for modeling the sustainability of subsistence hunting in tropical forests

Subsistence hunting provides a crucial food source for rural populations in tropical forests, but it is often practiced unsustainably. We use the empirical observation that subsistence hunters are central-place foragers to develop three "bio-demographic" hunting models of increasing complexity and realism for assessing the sustainability of hunting of an indicator species. In all our models, we calculate the spatial pattern of depletion of an indicator species (here, a large-bodied primate) across a landscape. Specifically, we show how to identify the area surrounding a human settlement that is expected to suffer local extinction. Our approach is an improvement over well-known sustainability indices of hunting, which are prone to error and do not provide clear links to policy prescriptions. Our first approach models the long-term effect of a single settlement and (1) can be parameterized with easily obtainable field data (such as settlement maps and knowledge of the major weapon used), (2) is simple enough to be used without requiring technical skill, and (3) reveals the asymptotic relationship between local human density and the level of game depletion. Our second model allows multiple settlements with overlapping hunting zones over large spatial scales. Our third model additionally allows temporal changes in human population size and distribution and source-sink dynamics in game populations. Using transect and hunting data from two Amazonian sites, we show that the models accurately predict the spatial distribution of primate depletion. To make these methods accessible, we provide software-based tools, including a toolbox for ArcGIS, to assist in managing and mapping the spatial extent of hunting. The proposed application of our models is to allow the quantitative assessment of settlement stabilization approaches to managing hunting in Amazonia.

Phylogenetic origins of local-scale diversity patterns and the causes of Amazonian megadiversity

What explains the striking variation in local species richness across the globe and the remarkable diversity of rainforest sites in Amazonia? Here, we apply a novel phylogenetic approach to these questions, using treefrogs (Hylidae) as a model system. Hylids show dramatic variation in local richness globally and incredible local diversity in Amazonia. We find that variation in local richness is not explained primarily by climatic factors, rates of diversification (speciation and extinction) nor morphological variation. Instead, local richness patterns are explained predominantly by the timing of colonization of each region, and Amazonian megadiversity is linked to the long-term sympatry of multiple clades in that region. Our results also suggest intriguing interactions between clade diversification, trait evolution and the accumulation of local richness. Specifically, sympatry between clades seems to slow diversification and trait evolution, but prevents neither the accumulation of local richness over time nor the co-occurrence of similar species.

Atmospheric versus vegetation controls of Amazonian tropical rain forest evapotranspiration: Are the wet and seasonally dry rain forests any different?

This study analyzes evapotranspiration data for three wet and two seasonally dry rain forest sites in Amazonia. The main environmental (net radiation, vapor pressure deficit, and aerodynamic conductance) and vegetation (surface conductance) controls of evapotranspiration are also assessed. Our research supports earlier studies that demonstrate that evapotranspiration in the dry season is higher than that in the wet season and that surface net radiation is the main controller of evapotranspiration in wet equatorial sites. However, our analyses also indicate that there are different factors controlling the seasonality of evapotranspiration in wet equatorial rain forest sites and southern seasonally dry rain forests. While the seasonality of evapotranspiration in wet equatorial forests is driven solely by environmental factors, in seasonally dry forests, it is also biotically controlled with the surface conductance varying between seasons by a factor of approximately 2. The identification of these different drivers of evapotranspiration is a major step forward in our understanding of the water dynamics of tropical forests and has significant implications for the future development of vegetation‐atmosphere models and land use and conservation planning in the region.

IMMUNITY: Mercury Alters Immune System Response in Artisanal Gold Miners

The link between mercury and damage to human health is not new: scientists showed several decades ago that an organic form of mercury known as methylmercury causes adverse effects on human neurodevelopment. More recently, scientists have observed associations between immune system disorders and exposure to both organic and inorganic (elemental) mercury.1,2 A new study of artisanal miners in Brazil could strengthen the link between mercury and immune system problems in humans.3 The results of the small-scale cross-sectional study may also apply to other communities exposed to low levels of inorganic mercury, the authors say. People living downstream from artisanal gold mining sites in Amazonia, Southeast Asia, China, Mongolia, and sub-Saharan Africa are exposed to methylmercury via fish in streams and rivers polluted by small-scale gold mining operations. But public health specialists have long been concerned about more direct exposures to mercury for the miners themselves, who inhale vapors when they burn off mercury they have used to amalgamate gold during the recovery of the precious metal. They also can absorb mercury through their skin as they knead it into the soil sediment to amalgamate the gold—a job Renee Gardner of the Karolinska Institute in Sweden says is often given to children. Gardner and Ellen Silbergeld of The Johns Hopkins University led a team of researchers attempting to tease out those direct effects of such inorganic mercury exposures. The team started with surveys of artisanal miners in Brazil who worked with either gold, emeralds, or diamonds. The data gathered covered five encampments of artisanal miners, with nearly 250 men and women participating. The researchers collected blood, urine, and hair samples, and screened participants for malaria along with other factors such as residence time at the mining site. The team measured two immunoglobins (proteins affiliated with autoimmune responses): antinuclear autoantibodies (ANA) and antinucleolar autoantibodies (ANoA). After accounting for infection with malaria, which also stimulates an immune response, their results showed a higher likelihood of ANA and ANoA being detected in miners currently working with gold compared with those mining for emeralds or diamonds, who do not use mercury in their work. However, a small number of gemstone miners—29% of whom reported using mercury in the past—also had detectable levels of ANA, ANoA, or both. Past research2 from some of the team members documented the effects of mercury on activated immune cells in terms of the release of seven cytokines associated with pro- and anti-inflammatory effects in the immune system; that in vitro study guided the development of a panel of biomarkers that might characterize human immune sensitivity to mercury compounds. In the current study, mercury exposure correlated with significantly increased levels of three pro-inflammatory cytokines. The authors say these cytokines could serve as biomarkers of mercury-induced immune responses similar to those seen in lupus-like disease (systemic lupus erythematosus is an autoimmune disease that causes chronic inflammation). “Since these immune changes that we saw were not related to whether or not miners were infected with malaria, the effects were most likely from exposure to mercury,” says coauthor Jennifer Nyland of the University of South Carolina School of Medicine. “We hope [the findings] can be applied to other individuals, as mercury is a global problem. Even if we stopped all small-scale mining in Africa or Brazil, there are still plenty of other sources of mercury”—including measurable mercury contamination in the western United States from historic gold mining.4,5 “I think the implications are important and may also relate to exposures in the United States from [mercury-bearing] amalgam fillings and religious uses of mercury,” says Philippe Grandjean of the Harvard School of Public Health, who was not involved with the study. Grandjean says that although the new study points to inorganic mercury as a possible trigger of immune dysfunction, the miners’ long-term mercury exposures were not well documented, and malaria infection could still confound the team’s results. He also points out that although one mining community had high mercury vapor exposure alongside high malaria prevalence, others had low mercury exposure and little malaria; that makes the effects of malaria and mercury exposure difficult to tease out epidemiologically from this one study. “What we have is a snapshot,” Nyland says of the latest study. Ideally, the team will expand their fieldwork into a larger-scale longitudinal study. They hope to establish partnerships in Brazil to prospectively study ongoing exposure to mercury in artisanal gold miners.

Anurans and Lizards, Rio Preto da Eva, Amazonas, Brazil

This study presents a list of anurans and lizards of a Central Amazonian terra-firme rainforest site at Rio Preto da Eva, Amazonas, Brazil sampled for 38 days from December 2003 to February 2004. The study area is located close to highway AM-010 (Manaus-Itacoatiara), where deforestation represents the main threat to the local biota. Using two complementary sampling methods, active search and pitfall traps with drift fence, we recorded 23 anuran species in 12 genera and six families and 20 lizard species in 16 genera and seven families. Relative to other sites in Central Amazon, our study site presented a similar number of species of lizards but fewer amphibians.

The Need for Large-Scale, Integrated Studies of Biodiversity - the Experience of the Program for Biodiversity Research in Brazilian Amazonia

Abstract Brazilian Amazonia covers around 5 million km 2 . If we could sample it regularly, with one sample for each 1 degree cell (10,000 km 2 ), 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 Chao, 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.

The role of Amazonian rivers for wintering ospreys (Pandion haliaetus): clues from North American band recoveries in Brazil between 1937 and 2006

In this paper we describe band-recovery data from 90 ospreys (Pandion haliaetus), banded in North America and recovered in Brazil between 1937 and 2006. Data were obtained from the Bird Banding Laboratory (US Geological Survey, USA) and from the Centro Nacional de Pesquisa para Conservação das Aves Silvestres (IBAMA, Brazil). The majority of ospreys were banded near the coast in Maryland, New Jersey, and Virginia. The birds were mainly recovered in Brazilian Amazonian states of Amazonas and Pará, near large rivers. The bulk of recoveries were of birds shot less than one year after banding. Distances from banding and recovery sites were between 4191 and 7722 km. Elapsed time between banding and recapture were between 50 and 9752 days. We described in this study one of the oldest band returns, and we report the first osprey band recoveries for four Brazilian States (Paraíba, Ceará, Rondônia, and Tocantins). The importance of Brazil for ospreys, mainly Amazonian sites, needs to be emphasized in educational programs and considered in international conservation strategies.

Pollen-based biome reconstructions for Latin America at 0, 6000 and 18 000 radiocarbon years ago

Abstract. The biomisation method is used to reconstruct Latin American vegetation at 6000±500 and 18 000±1000 radiocarbon years before present (14C yr BP) from pollen data. Tests using modern pollen data from 381 samples derived from 287 locations broadly reproduce potential natural vegetation. The strong temperature gradient associated with the Andes is recorded by a transition from high altitude cool grass/shrubland and cool mixed forest to mid-altitude cool temperate rain forest, to tropical dry, seasonal and rain forest at low altitudes. Reconstructed biomes from a number of sites do not match the potential vegetation due to local factors such as human impact, methodological artefacts and mechanisms of pollen representivity of the parent vegetation. At 6000±500 14C yr BP 255 samples are analysed from 127 sites. Differences between the modern and the 6000±500 14C yr BP reconstruction are comparatively small; change relative to the modern reconstruction are mainly to biomes characteristic of drier climate in the north of the region with a slight more mesic shift in the south. Cool temperate rain forest remains dominant in western South America. In northwestern South America a number of sites record transitions from tropical seasonal forest to tropical dry forest and tropical rain forest to tropical seasonal forest. Sites in Central America show a change in biome assignment, but to more mesic vegetation, indicative of greater plant available moisture, e.g. on the Yucatán peninsula sites record warm evergreen forest, replacing tropical dry forest and warm mixed forest presently recorded. At 18 000±1000 14C yr BP 61 samples from 34 sites record vegetation reflecting a generally cool and dry environment. Cool grass/shrubland is prevalent in southeast Brazil whereas Amazonian sites record tropical dry forest, warm temperate rain forest and tropical seasonal forest. Southernmost South America is dominated by cool grass/shrubland, a single site retains cool temperate rain forest indicating that forest was present at some locations at the LGM. Some sites in Central Mexico and lowland Colombia remain unchanged in the biome assignments of warm mixed forest and tropical dry forest respectively, although the affinities that these sites have to different biomes do change between 18 000±1000 14C yr BP and present. The "unresponsive" nature of these sites results from their location and the impact of local edaphic influence.

Análise estrutural da floresta tropical úmida do município de Alta Floresta, Mato Grosso, Brasil

Este trabalho teve como objetivo estudar a composição e estrutura de um estrato arbóreo da floresta tropical úmida em Alta Floresta - MT, determinando os padrões de semelhança com outras regiões da Amazônia brasileira. O estudo foi realizado em uma área de 2 hectares, dividida em 20 parcelas de 10x 100m, onde foram mensurados a altura e o DAP ≥ 10 cm de todos os indivíduos. Para avaliação do grau de similaridade entre a composição florística e estrutura arbórea de Alta Floresta com as nove regiões pertencentes à Amazônia Legal brasileira, utilizou-se o método de agrupamento hierárquico aglomerativo com ligações pela média dos grupos (UPGMA), por meio do índice de Sorensen (qualitativo). Para a ordenação, foi utilizado o mesmo programa, utilizando a Escalonamento Multidimensional não-métrica (NMS) por meio do índice de Jaccard aplicado à presença e ausência de famílias e gêneros. Para análise de similaridade entre as 10 regiões, comparando a matriz de distâncias físicas entre elas com as matrizes de composição de famílias e gêneros, utilizou-se o programa PATN por meio do Teste de Mantel com o índice de Jaccard. A região apresentou 1101 indivíduos, pertencentes a 32 famílias, 54 gêneros e 68 espécies. A família com maior riqueza de espécie foi Leguminosae. A espécie Helicostilys podogyne e o gênero Cecropia sp. foram as mais importantes no levantamento. A floresta tropical úmida de Alta Floresta não se assemelhou com nenhuma das nove regiões comparadas neste estudo.

Helminths of the teiid lizard Kentropyx calcarata (Squamata) from an Amazonian site in western Brazil

Despite being conspicuous members of neotropical lizard communities, aspects of the life history of many teiid lizard species are poorly known, especially endoparasites infecting the genus Kentropyx. We studied seven specimens of K. calcarata collected at an Amazonian site in Mato Grosso state, Central Brazil in 2007. Four species of helminth were recovered: Oswaldocruzia sp., Piratuba digiticauda, Physaloptera retusa and Physalopteroides venancioi. Piratuba digiticauda, a body-cavity, parasite had the highest prevalence (42.9%), whereas the stomach parasites P. venancioi and P. retusa presented the highest intensity of infection and abundance, respectively. Moreover, this is the first report of Oswaldocruzia sp., P. digiticauda and P. venancioi in K. calcarata and new locality records for all nematodes were assigned.

Comprehensive assessment of carbon productivity, allocation and storage in three Amazonian forests

AbstractThe allocation and cycling of carbon (C) within forests is an important component of the biospheric C cycle, but is particularly understudied within tropical forests. We synthesise reported and unpublished results from three lowland rainforest sites in Amazonia (in the regions of Manaus, Tapajós and Caxiuanã), all major sites of the Large‐Scale Biosphere–Atmosphere Programme (LBA). We attempt a comprehensive synthesis of the C stocks, nutrient status and, particularly, the allocation and internal C dynamics of all three sites. The calculated net primary productivities (NPP) are 10.1±1.4 Mg C ha−1 yr−1 (Manaus), 14.4±1.3 Mg C ha−1 yr−1 (Tapajós) and 10.0±1.2 Mg C ha−1 yr−1 (Caxiuanã). All errors bars report standard errors. Soil and leaf nutrient analyses indicate that Tapajós has significantly more plant‐available phosphorus and calcium. Autotrophic respiration at all three sites (14.9–21.4 Mg C ha yr−1) is more challenging to measure, with the largest component and greatest source of uncertainty being leaf dark respiration. Comparison of measured soil respiration with that predicted from C cycling measurements provides an independent constraint. It shows general good agreement at all three sites, with perhaps some evidence for measured soil respiration being less than expected. Twenty to thirty percent of fixed C is allocated belowground. Comparison of gross primary productivity (GPP), derived from ecosystem flux measurements with that derived from component studies (NPP plus autotrophic respiration) provides an additional crosscheck. The two approaches are in good agreement, giving increased confidence in both approaches to estimating GPP. The ecosystem carbon‐use efficiency (CUEs), the ratio of NPP to GPP, is similar at Manaus (0.34±0.10) and Caxiuanã (0.32±0.07), but may be higher at Tapajós (0.49±0.16), although the difference is not significant. Old growth or infertile tropical forests may have low CUE compared with recently disturbed and/or fertile forests.

Species richness and structure of three Neotropical bat assemblages

We compared the assemblages of phyllostomid bats in three Neotropical rainforests with respect to species richness and assemblage structure and suggested a method to validate estimates of species richness for Neotropical bat assemblages based on mist-netting data. The fully inventoried bat assemblage at La Selva Biological Station (LS, 100 m elevation) in Costa Rica was used as a reference site to evaluate seven estimators of species richness. The Jackknife 2 method agreed best with the known bat species richness and thus was used to extrapolate species richness for an Amazonian bat assemblage (Tiputini Biodiversity Station; TBS, 200 m elevation) and an Andean premontane bat assemblage (Podocarpus National Park; BOM, 1000 m elevation) in Ecuador. Our results suggest that more than 100 bat species occur sympatrically at TBS and about 50 bat species coexist at BOM. TBS harbours one of the most species-rich bat assemblages known, including a highly diverse phyllostomid assemblage. Furthermore, we related assemblage structure to large-scale geographical patterns in floral diversity obtained from botanical literature. Assemblage structure of these three phyllostomid assemblages was influenced by differences in floral diversity at the three sites. At the Andean site, where understorey shrubs and epiphytes exhibit the highest diversity, the phyllostomid assemblage is mainly composed of understorey frugivores and nectarivorous species. By contrast, canopy frugivores are most abundant at the Amazonian site, coinciding with the high abundance of canopy fruiting trees. Assemblage patterns of other taxonomic groups also may reflect the geographical distribution patterns of floral elements in the Andean and Amazonian regions. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 94, 617–629.

Land use decisions in smallholder rural communities in developing countries.

Abstract Land use change has become increasingly acknowledged as an important issue in terms of understanding the processes of global change. Hence, land use decision-making by smallholder communities in developing countries become a vital part of the broader comprehension of environmental and social change that are related to the change processes at the global scale. A wide range of analytical and conceptual frameworks has been developed to facilitate and sharpen such analyses, ranging from very theoretical to directly operational approaches. Five regional cases are used to illustrate the diversity of land use decisions and drivers of decisions. These range from political decisions on land tenure and development (Tanzania, Vietnam and Borneo) to the global effects of climate change (Sahel), and represent a diversity of contexts from the agricultural frontiers of humid tropical sites in Amazonia and Borneo to the more intensively farmed and long-settled tropical dryland areas of the Sahel. We conclude that although there are specific issues in all areas, the multiplicity of drivers for land use change is always important and necessary to capture if adequate understanding and development is to be achieved. The analytical and conceptual frameworks presented are useful for ensuring this.

The effects of biomass burning aerosols and clouds on the CO2 flux in Amazonia

Aerosol particles associated with biomass burning emissions affect the surface radiative budget and net ecosystem exchange (NEE) over large areas in Amazonia during the dry season. We analysed CO2 fluxes as a function of aerosol loading for two forest sites in Amazonia as part of the LBA experiment. Aerosol optical thickness (AOT) measurements were made with AERONET sun photometers, and CO2 flux measurements were determined by eddy-correlation.The enhancement of the NEE varied with different aerosol loading, as well as cloud cover, solar elevation angles and other parameters. The AOT value with the strongest effect on the NEE in the FLONA-Tapajós site was 1.7, with an enhancement of the NEE of 11% compared with clear-sky conditions. In the RBJ site, the strongest effect was for AOT of 1.6 with an enhancement of 18% in the NEE. For values of AOT lager than 2.7, strong reduction on the NEE was observed due to the reduction in the total solar radiation. The enhancement in the NEE is attributed to the increase of diffuse versus direct solar radiation. Due to the fact that aerosols from biomass burning are present in most tropical areas, its effects on the global carbon budget could also be significant.

Density, Territory Size, and Long-Term Spatial Dynamics of a Guild of Terrestrial Insectivorous Birds Near Manaus, Brazil

Abstract From 1994 to 2003, I annually surveyed terrestrial insectivorous birds in a 100-ha plot within continuous rainforest near Manaus, Brazil. I used spot-map registrations and radiotagged birds to estimate territory size and density on the plot for 13 species. As in the few previous studies of Amazonian birds, territory sizes were large (mean = 13.0 ha) and densities were low (mean = 3.4 pairs per 100 ha). The most common species, Formicarius colma, was the only species with >10 pairs per 100 ha, and one of four species (with Myrmeciza ferruginea, Conopophaga aurita, and Corythopis torquatus) to have territories of <7.0 ha. On average, each species occupied 34% of the plot, with only four species (F. colma, Grallaria varia, F. analis, and M. ferruginea) ever occupying >50% in any year. Territories appeared and disappeared between surveys; ∼71% of territories detected in a given survey were present in the next survey. The two rarest species, Myrmothera campanisona and Hylopezus macularius, were absent from the plot in some years. Across species, territory stability was positively correlated with abundance; more common species had more stable density among years than rare species. Although past research has shown territory stability for the most common species of Neotropical rainforest birds, my results suggest that rarer species, which constitute the bulk of the avifauna, may show greater fluctuation in abundance. I compared my results to similar data from lowland rainforests in Panama, French Guiana, Ecuador, and Peru. Species richness was lowest in Panama, but comparable among the Amazonian sites. Panama also had the highest biomass and smallest territory sizes. Interestingly, relative abundances of species shared among sites were not necessarily similar. With the exception of Conopophaga spp., all species or replacement species shared among sites were at least twice as abundant at one site as at another. Relative abundance within genera also differed among sites for Sclerurus and Formicarius. The sparse data available so far suggest that individual species show considerable spatial variation in abundance across Amazonia, though the mechanisms and the texture of the patterns remain unknown. Densidade, Tamanho do Território, e Dinamismo Espacial ao Longo Prazo das Aves Insetívoras Terrestres perto de Manaus, Brasil

Responses of squirrel monkeys to seasonal changes in food availability in an eastern Amazonian forest

Tropical forests are characterized by marked temporal and spatial variation in productivity, and many primates face foraging problems associated with seasonal shifts in fruit availability. In this study, I examined seasonal changes in diet and foraging behaviors of two groups of squirrel monkeys (Saimiri sciureus), studied for 12 months in Eastern Brazilian Amazonia, an area characterized by seasonal rainfall. Squirrel monkeys were primarily insectivorous (79% of feeding and foraging time), with fruit consumption highest during the rainy season. Although monkeys fed from 68 plant species, fruit of Attalea maripa palms accounted for 28% of annual fruit-feeding records. Dietary shifts in the dry season were correlated with a decline in ripe A. maripa fruits. Despite pronounced seasonal variation in rainfall and fruit abundance, foraging efficiency, travel time, and distance traveled remained stable between seasons. Instead, squirrel monkeys at this Eastern Amazonian site primarily dealt with the seasonal decline in fruit by showing dietary flexibility. Consumption of insects, flowers, and exudates increased during the dry season. In particular, their foraging behavior at this time strongly resembled that of tamarins (Saguinus sp.) and consisted of heavy use of seed-pod exudates and specialized foraging on large-bodied orthopterans near the forest floor. Comparisons with squirrel monkeys at other locations indicate that, across their geographic range, Saimiri use a variety of behavioral tactics during reduced periods of fruit availability.

Bats of Jaú National Park, central Amazônia, Brazil

Although recognized as highly diverse, the bat fauna of the Amazon basin has been only patchily sampled. This paper combines data from five short surveys conducted between 1998 and 2001 in Jau National Park, 220 km east of Manaus, central Amazonia. We used mistnets, recordings of echolocation calls and roost visits to provide the first bat inventory for this area. A total of 53 bat species in 33 genera and five families were documented, including several species that are regarded as rare, in particular Saccopteryx gymnura, Vampyriscus brocki, Molossops neglectus, and Promops centralis. The Chao 1 index indicates that sampling is about 72% complete, suggesting that around 73 bat species might co-exist in Jau. We compare the composition of Jau's bat fauna to those of other sites in Amazonia and interpret the resulting patterns of diversity. Data on reproduction are given for 14 species.

Bats of the Reserva Nacional Allpahuayo-Mishana, Northeastern Peru, with Notes on Community Structure

An inventory of the bat fauna at the Reserva Nacional Allpahuayo-Mishana documented 63 species. Coupled with previous records, this becomes the second most species-rich site for bats in Peru, with 65 species. Reproductively, there was a peak in activity in the early rainy season (October—December) that steadily declined to a low in the late rainy or early dry season (May—June). The community was dominated by Carollia perspicillata in terms of relative abundance and biomass. Most species were frugivores (28) or insectivores (26), but frugivores were predominant in the community based on cumulative abundance and biomass. The bat fauna was sampled to 85–91% completion based on extrapolations of local species richness. Nonetheless, only 56% of the regional species pool was captured locally. The fauna was compositionally similar to that of other western Amazonian sites. Although the Reserva Nacional Allpahuayo-Mishana enjoys a relatively high protected status, this has yet to be translated into sustained conservation. As a hotspot of biodiversity in Peru, it deserves protection at the highest possible level.

Diversity and biogeography of vascular epiphytes in Western Amazonia, Yasuní, Ecuador

AbstractAim Although vascular epiphytes are important components of species richness and complexity of Neotropical forests, vascular epiphytes are under‐represented in large scale biogeographical analyses. We studied the diversity, biogeography and floristic relationships of the epiphytic flora of the Yasuní region (Western Amazonia) in a Neotropical context, with special emphasis on the influence of the Andean flora on floristic composition and diversity of surrounding lowland forests.Location Western Amazonian lowland rainforest, Tiputini Biodiversity Station (0°38′ S 76°09′ W, 230 m a.s.l., 650 ha), Yasuní National Park, Ecuador.Methods We compared the vascular epiphyte flora of Yasuní with 16 published Neotropical epiphyte inventories. Secondly, based on a floristic database with records of more than 70,000 specimens of vascular epiphytes from the Neotropics the elevational composition of eight selected inventories was analysed in detail.Results The vascular epiphyte flora of Yasuní is characterized by a very high species richness (313 spp.). A moderate portion of species is endemic to the Upper Napo region (c. 10%). However, this figure is much higher than previous analyses primarily based on woody species suggested. Geographical ranges of these species match with a proposed Pleistocene forest refuge. Compared with Northern and Central Amazonian sites, Western Amazonian epiphyte communities are characterized by a higher portion of montane and submontane species. Species richness of vascular epiphytes at the sites was correlated with the amount of rainfall, which is negatively correlated with the number of dry months.Main conclusion Recent and historic patterns of rainfall are the driving forces behind diversity and floristic composition of vascular epiphytes in Western Amazonia: high annual rainfall in combination with low seasonality provides suitable conditions to harbour high species richness. The proximity to the Andes, the most important centre of speciation for most Neotropical epiphytic taxa, in combination with the climatic setting has allowed a continuous supply of species richness to the region. At least for epiphytes, the borderline between the Andean and Amazonian flora is much hazier than previously thought. Moreover, the comparatively moist climate in Western Amazonia during the Pleistocene has probably led to fewer extinctions and/or more speciation than in more affected surrounding lowlands.