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Understanding the direct and indirect effects of niche and neutral processes in structuring species diversity is particularly challenging because environmental factors are often geographically structured. Here, we used Structural Equation Modeling to quantify direct and indirect effects of geographic distance, the Amazon River's opposite margins, and environmental differences in temperature, precipitation, and vegetation density (Normalized Difference Vegetation Index-NDVI) on ant beta diversity (Jaccard's dissimilarity) across Amazon basin. We used a comprehensive survey of ground-dwelling ant species from 126 plots distributed across eight sampling sites along a broad environmental gradient. We found that geographic distance and NDVI differences were the major direct predictors of ant composition dissimilarity. The major indirect effect was that of temperature through NDVI, whereas precipitation neither had direct or indirect detectable effects on beta diversity. Thus, ant compositional dissimilarity seems to be mainly driven by a combination of isolation by distance (through dispersal limitation) and selection imposed by vegetation density, and indirectly, by temperature. Our results suggest that neutral and niche processes have been similarly crucial in driving the current beta diversity patterns of Amazonian ground-dwelling ants.

Geographic isolation plays a major role in biological diversification. Yet, adaptive divergence also can occur with ongoing gene flow, but the minimal spatial scale required for this is unclear. Here, we hypothesized that local gradients in soil clay and water contents respectively select for anti-adherent and hypoxia-tolerant phenotypes in soil invertebrates, thereby driving intraspecific phenotypic divergence despite unlimited, passive dispersal. We tested this idea using the parthenogenetic oribatid mite Rostrozetes ovulum, an abundant species in tropical forest soils. We obtained 40 individuals from valleys and uplands within 4 km2 of rainforest in central Amazonia, and estimated soil clay and water contents for each site. Then, we experimentally assessed submersion tolerance of each individual, measured its body size, shape and structural traits, and inferred anti-adherence from the extent of debris attached to its body. We found that morphological distance was greater between than within habitats while being independent of geographic distance, which itself was unrelated to habitat. Further, using structural equation modelling, we found that clayish soils harboured mites with fewer, larger dorsal pits that were less likely to have attached debris, consistent with an anti-adherent morphology. To a lower degree, individuals from moister soils tended to survive submersion longer, likely through anaerobiosis. These patterns could reflect phenotypic plasticity, local adaptation or some combination thereof. Altogether, they suggest that environmental gradients may trigger local-scale animal diversification in soils, contributing to the exceptional biodiversity of this substrate.

Assessments of fish communities tend to rely on capture‐based methods that, due to sampling biases, can underestimate actual species richness. Alternatively, environmental DNA (eDNA) based metabarcoding is a noncapture approach that infers species richness and distribution by collecting and sequencing DNA present in the ecosystem. Here, eDNA metabarcoding was applied to the lower River Severn, a highly modified and impounded river, to identify the species present in the fish assemblage. Using a universal primer for fish (12S mtDNA region), comparisons were made between the species identified as present by eDNA metabarcoding versus long‐term data available from fisheries monitoring data based on capture methods. Depending on the stringency of detection thresholds applied, the two methods detected between 15 and 25 fish species present in the river, with the eDNA metabarcoding detecting most species previously reported in the capture surveys, although with differences in the relative abundance of species between the methods. Notably, eDNA metabarcoding detected species of high conservation importance that were never sampled by capture techniques, including native European shads (Alosa spp.). Differences in the similarity indices of species detection were greater between the sampling methods than between sampling sites on each river. These results highlight the high potential of eDNA metabarcoding to provide an effective monitoring tool for biodiversity and conservation in rivers, but also indicate the need for complementary multi‐method sampling for robust estimates of fish species richness.

To determine the effect of rivers, environmental conditions, and isolation by distance on the distribution of species in Amazonia. Location: Brazilian Amazonia. Time period: Current. Major taxa studied: Birds, fishes, bats, ants, termites, butterflies, ferns + lycophytes, gingers and palms. We compiled a unique dataset of biotic and abiotic information from 822 plots spread over the Brazilian Amazon. We evaluated the effects of environment, geographic distance and dispersal barriers (rivers) on assemblage composition of animal and plant taxa using multivariate techniques and distance- and raw-data-based regression approaches. Environmental variables (soil/water), geographic distance, and rivers were associated with the distribution of most taxa. The wide and relatively old Amazon River tended to determine differences in community composition for most biological groups. Despite this association, environment and geographic distance were generally more important than rivers in explaining the changes in species composition. The results from multi-taxa comparisons suggest that variation in community composition in Amazonia reflects both dispersal limitation (isolation by distance or by large rivers) and the adaptation of species to local environmental conditions. Larger and older river barriers influenced the distribution of species. However, in general this effect is weaker than the effects of environmental gradients or geographical distance at broad scales in Amazonia, but the relative importance of each of these processes varies among biological groups.

Three processes can explain contemporary community assembly: natural selection, ecological drift and dispersal. However, quantifying their effects has been complicated by confusion between different processes and neglect of expected interactions among them. One possible solution is to simultaneously model the expected effects of each process within species, across communities and across species, thus providing more integrative tests of ecological theory. Here, we used generalized linear mixed models to assess the effects of selection, drift and dispersal on the occurrence probability of 135 soil oribatid mite species across 55 sites over an Amazonian rainforest landscape (64 km

Survey costs and a lack of taxonomists are often the main impediments to biodiversity inventories. The use of a higher-taxon approach that is efficient in representing species patterns within a short period of time is one way to overcome these constraints, especially if these responses are consistent at various spatial scales and sampling techniques. Here, we evaluated whether the use of pitfall trapping or Winkler extraction influenced the utility of genus as a surrogate to predict patterns of species richness and composition related to environment. The study sites were spread along 10 degrees of latitude, covering phytophysiognomies with different topographic characteristics. We recorded 450 ant species/morphospecies distributed in 70 genera. Pitfall-traps captured a larger proportion of species (77–98%) and genera (71–100%) per site. Genus was efficient in predicting variations in richness, and assemblage composition detected at the species level, using pitfall-traps or Winkler extractors. The higher-taxon approach saved approximately 40% of the surveys costs. The negative effect of the species-genus ratio was detected only on species composition, but it did not affect the quality of predictions using genera. The results are consistent with the hypothesis that genus can be used as a proxy for broader sets of species independent of sampling technique or environmental heterogeneity. The use of pitfall-traps or Winkler extractors for genus-level identification proved to be cost-efficient and time-efficient and should work well in other regions requiring conservation effort and monitoring programs.

1. Understanding the causes of the spatial variation of biodiversity is an important goal in community ecology. This study investigated the response of fruit‐feeding butterfly assemblages to environmental gradients resulting from the transition from ombrophilous forests to white‐sand forests in northern Brazil by assessing taxonomic, functional and phylogenetic descriptors of community structure. 2. Butterflies were sampled with bait traps in the Brazilian Amazon, while their traits and phylogenetic relatedness were either measured directly or gathered from the literature. Then, the effects of plant species turnover, light intensity, and flood risk on butterfly community patterns were tested. 3. Butterfly abundance increased with light intensity in non‐forested white‐sand habitats, whereas ombrophilous forests harboured higher species richness. A trade‐off was observed between richness and abundance across the gradient. Plant turnover strongly drove shifts in butterfly species composition. In white‐sand habitats, butterflies had higher dispersal capacity, faster flights and generalist larvae, whereas in periodically flooded plots the functional diversity of flight‐related traits was higher. No phylogenetic response to environmental gradients was detected. 4. These results exposed the complexity of community structure across a mosaic landscape and how analysing more than one dimension of biodiversity may reveal underlying relationships not apparent under isolated approaches. Caution is required when using phylogeny as a proxy for functional similarity, as the responses were not congruent in this study. The ecological patterns revealed here, aligned with further regional‐scale studies, can provide complementary perspectives on butterfly spatial distribution and ensure that appropriate conservation policies are developed.

Surveys on tropical invertebrates must gather as much information as possible over the shortest period, mainly because of financial limitations and hyperdiversity. Fruit-feeding butterflies in the subfamilies Biblidinae, Charaxinae, Nymphalinae and Satyrinae (Nymphalidae) are attracted to decaying material and can be sampled with standardized methodologies, but (1) some groups can be difficult to collect, despite being quite common in Amazonian forest understorey; moreover, (2) the duration of the sampling period is not consistent among studies and (3) the sufficient effort for financially limited projects remains unknown. With this study, we aimed to fulfill points 1–3 in order to recommend a less costly protocol for monitoring purposes in the Amazon. In 25 km2 of rainforest in the state of Amazonas, Brazil, we evaluated the performance of sampling schemes for these butterflies (four, three, two and one visit in 250 m-long plots), using both nets and bait traps, while considering reductions in sampling effort and the removal of rare and infrequent taxa to optimize field and laboratory work. Reduced-effort schemes are only validated if they reflect both taxonomic and ecological information provided by the maximum effort. Procrustes superimposition was used to estimate the dissimilarity in the spatial distribution of species between schemes. Spatial turnover in herb, liana, palm tree and diameter-at-breast-height > 10 cm tree species composition was used as predictor for the butterfly community through linear regressions. The three-visit scheme was sufficient to retrieve high species similarity and the ecological patterns observed with maximum effort. The two-visit scheme lost a significant amount of information on species composition similarity, but recovered stronger environmental relationships than those observed with the four-visit scheme. The removal of uncommon species did not affect the ecological response of the community, thereby suggesting that common species are driving the spatial patterns of the studied butterflies. Thus, large reductions in costs by reducing sampling effort could be achieved with relatively little loss of information on the species turnover of butterflies and their relationships with the environment. The proposed sampling protocols with reduced effort will allow projects to use their time and financial supply more effectively, showing that cost-effective shortcuts for biodiversity assessments can be useful for conservation, biomonitoring and land use management.

This study investigated the spatial distribution of an Amazonian fruit-feeding butterfly assemblage by linking species taxonomic and functional approaches. We hypothesized that: 1) vegetation richness (i.e., resources) and abundance of insectivorous birds (i.e., predators) should drive changes in butterfly taxonomic composition, 2) larval diet breadth should decrease with increase of plant species richness, 3) small-sized adults should be favored by higher abundance of birds, and 4) communities with eyespot markings should be able to exploit areas with higher predation pressure. Fruit-feeding butterflies were sampled with bait traps and insect nets across 25 km(2) of an Amazonian ombrophilous forest in Brazil. We measured larval diet breadth, adult body size, and wing marking of all butterflies. Our results showed that plant species richness explained most of the variation in butterfly taxonomic turnover. Also, community average diet breadth decreased with increase of plant species richness, which supports our expectations. In contrast, community average body size increased with the abundance of birds, refuting our hypothesis. We detected no influence of environmental gradients on the occurrence of species with eyespot markings. The association between butterfly taxonomic and functional composition points to a mediator role of the functional traits in the environmental filtering of butterflies. The incorporation of the functional approach into the analyses allowed for the detection of relationships that were not observed using a strictly taxonomic perspective and provided an extra insight into comprehending the potential adaptive strategies of butterflies.

Aim Despite the accelerating loss of biodiversity and the increased number of methods for conservation planning, the availability of information about the spatial distribution of biodiversity remains limited. One way to overcome this problem is to focus on surrogate resolutions that are able to represent species-level data and can be efficiently measured. Surrogates are only useful if the ecological patterns detected at the species-level still hold when based on coarser taxonomic identification, and if these responses are consistent across regions. We present a comprehensive analysis using data from a large-scale evaluation of ground-dwelling ants, to evaluate the use of surrogates. Location Amazon basin. Methods The sampling design covered 13 sites in eight phytophysiognomies, which in conjunction with other environmental characteristics (altitude, soil granulometry and slope) were used to validate the ecological patterns (ability of the surrogates to reproduce the ecological responses identified for species) of coarser surrogate taxa (indicator taxa, mixed-level approach, genus and subfamily). The surrogates were evaluated for their capacity to predict variation in total species richness and composition. We also estimated the monetary and time costs, in order to evaluate the cost-effectiveness of using different surrogate levels. Results Genus was the most cost-effective surrogate: it predicted 81% of site variation in species richness, was highly correlated (r2 = 0.76) with species composition, very highly correlated (r2 = 0.97) with ecological patterns detected at species level and saved ~40% of total project costs. The mixed-level approach, indicator taxa and subfamily were not effective in representing the species-level data. Main conclusions Genus can be used as a surrogate for species, due to its high predictive value, independent of environmental heterogeneity. Genus may be useful as a surrogate for species in other megadiverse regions, especially where savings in project costs can be applied to increase sampling effort.

The need for biodiversity conservation is increasing at a rate much faster than the acquisition of knowledge of biodiversity, such as descriptions of new species and mapping species distributions. As global changes are winning the race against the acquisition of knowledge, many researchers resort to the use of surrogate groups to aid in conservation decisions. Reductions in taxonomic and numerical resolution are also desirable, because they could allow more rapid the acquisition of knowledge while requiring less effort, if little important information is lost. In this study, we evaluated the congruence among 22 taxonomic groups sampled in a tropical forest in the Amazon basin. Our aim was to evaluate if any of these groups could be used as surrogates for the others in monitoring programs. We also evaluated if the taxonomic or numerical resolution of possible surrogates could be reduced without greatly reducing the overall congruence. Congruence among plant groups was high, whereas the congruence among most animal groups was very low, except for anurans in which congruence values were only slightly lower than for plants. Liana (Bignoniaceae) was the group with highest congruence, even using genera presence–absence data. The congruence among groups was related to environmental factors, specifically the clay and phosphorous contents of soil. Several groups showed strong spatial clumping, but this was unrelated to the congruence among groups. The high degree of congruence of lianas with the other groups suggests that it may be a reasonable surrogate group, mainly for the other plant groups analyzed, if soil data are not available. Although lianas are difficult to count and identify, the number of studies on the ecology of lianas is increasing. Most of these studies have concluded that lianas are increasing in abundance in tropical forests. In addition to the high congruence, lianas are worth monitoring in their own right because they are sensitive to global warming and the increasing frequency and severity of droughts in tropical regions. Our findings suggest that the use of data on surrogate groups with relatively low taxonomic and numerical resolutions can be a reliable shortcut for biodiversity assessments, especially in megadiverse areas with high rates of habitat conversion, where the lack of biodiversity knowledge is pervasive.

We recorded species abundance and richness of oribatid mites along 16 plots established in semi-deciduous forest fragments in Amazonia. The results were compared with a published dataset consisting of an inventory carried out in 38 plots in the surrounding savanna. Totals of 143 and 91 species were recorded in the forest fragments and savanna, respectively. Sorensen similarity index between both environments was 0.44. Ordination of sites according to oribatid mite species composition showed a clear separation between forest fragments and savanna. Rostrozetes ovulum, Archegozetes longisetosus and Eohypochthonius (Eohypochthonius) becki were abundant and frequent in the forest fragments but exceedingly rare in the savanna. Neoppia (Neoppia) schauenbergi, Pseudoppia sp. C, Microppia sp. A and Cosmochthonius sp. A were limited to the savanna. This study also represents an early step toward knowing which groups of species are exclusive to one or another vegetation type or are sensitive to their inherent enviro...

Using effective survey protocols to address the effects of environmental change are key to saving time, resources and costs. Although exhaustive sampling in any location has been shown as impractical, biodiversity sampling projects must capture sufficient information to show how species assemblages change with the environmental variables. This study investigated time of exposure in the field and the number of pitfall traps that efficiently sampled poneromorph ants in 30 250 m long plots across an area of 25 km2 of tropical rain forest in Brazil. The treatments used for the surveys included two days and 300 traps, 14 days and 300 traps, 14 days and 750 traps, and were considered the minimum, intermediate and maximum sampling efforts, respectively. We characterized each assemblage of ants in relation to a gradient of soil texture, terrain slope and leaf and branch litter volume, and then tested whether the ecological relationships observed with the maximum effort were comparable to data on intermediate and minimum sampling efforts. We also estimated the cost-effectiveness of using the protocols in survey programs. The assemblage of species sampled during 14 days was similar to the assemblage captured during two days, indicating that the number of days influenced the assemblage similarity more than the number of sampling traps. All ecological patterns detected with the maximum effort were also captured with lesser sampling efforts. Overall, both the intermediate and minimum sampling efforts represented savings around 2640% of total project costs and 4345% of time to process the samples. We recommend that two days of trapping time combined with 300 pitfall traps is a highly effective shortcut for monitoring assessment, which can be applied to large-scale biodiversity surveys in tropical forests. © 2018 Universidade Estadual de Feira de Santana. All rights reserved.

Sampling oribatid mites in large areas using conventional methods is expensive, time-consuming, and this constrains their use in environmental monitoring programs. We used samples collected in 38 plots of 3.75 ha spread over 30,000 ha in an Amazonian savanna to evaluate the reduction in costs and person-hours in sampling and sorting and to elaborate cost-effective protocols. Ten samples per plot were collected and extracted using a Berlese-Tullgren apparatus. In the laboratory, samples were reduced to 50, 25, 12.5, and 6.25 percent of the initial content. Field-effort reduction was estimated by reducing the number of subsamples per plot. Dissimilarity matrices were generated using Bray-Curtis, Sorensen, and Chao-Sorensen indices. Correlations between each reduced-effort dissimilarity matrix and 100 or 50 percent sorting were used as an index of how much information was retained in reduced-effort sampling, and could still be used in multivariate analyses. The effects of most predictor variables on mite composition were detected in data based on every level of sample reduction. The intensive sampling was insufficient to reveal the full oribatid-mite fauna in the savanna; as more plots were sampled, more species were recorded. Our data indicate subsampling protocols for biodiversity assessment of oribatid mites in savanna that increase field and laboratory efficiency, and optimize both taxonomic and ecological aspects of the investigation.

Globally, natural resource management agencies are increasingly recognizing the importance of long-term ecological research (LTER) for monitoring biodiversity, ranging from relatively simple, known, local-level issues, such as managing tourist impacts in a conservation park, to more complex, multifaceted, pervasive, and far-reaching impacts, such as global climate change. Much previous literature has confused protocols for LTER projects to answer current research questions, with developing a system for long-term ecological monitoring. Contrary to perceptions that these LTER systems are not driven by well-defined objectives, we argue that LTER systems can be designed and implemented with the specific objective of providing a basis for both LTER projects and long-term monitoring. We present an overview of RAPELD, an LTER system developed in Brazil, with comparable infrastructure established in Australia and Nepal. The standardized biodiversity infrastructure and research platform provides a long-term basis for powerful multi-disciplinary, multi-scale analyses.

Sea level rise and an increased frequency and severity of storm surge events due to climate change are likely to increase the susceptibility of low lying coastal areas to seawater flooding. An integral part of any coastal management strategy throughout European countries is the “do nothing” scenario; this is the benchmark against which putative intervention strategies are evaluated. While the prime concern of a flood defense scheme appraisal often focuses on the sustained financial “benefits” of an intervention, intrinsic to a complete multicriteria analysis is a comprehensive evaluation of the ecological and social consequences of coastal flooding, reflecting the needs of end users and satisfying relevant national and international policies. An ecological perspective may be usefully employed to examine the impact of the do nothing option on coastal environments (e.g. estuaries, sand dunes and grasslands) and businesses. Although at first sight coastal environmental and business systems appear quite different, they have similarities in that both are vulnerable and susceptible to flood damage or loss and both may be analyzed by employing ecological, adaptive, resilience frameworks. From an ecological perspective many coastal environments are of international conservation importance and provide important ecosystem services including coastal protection, nutrient cycling, carbon sequestration, food production and recreation. Nonetheless, despite their potential vulnerability to coastal flooding, our understanding of the effects of salinity on the biological response of many coastal plants and animals is extremely limited. We show here how plant physiology and patterns of plant and invertebrate distribution are impacted by sea water flooding. We also present responses of model plants to sea water inundation based on the Intergovernmental Panel on Climate Change (IPCC) (2007) predictions of sea level rise and storm surge events. Results showed that coastal habitats surveyed are relatively resilient to flooding due to their species rich nature and their ability to adapt to flooding. However specific groups of plants such as grasses are more affected by flooding and less able to recover. The socio-economic dimensions of doing nothing are addressed in relation to the impacts of coastal flooding specifically on business activity, which has received little attention to date. Here the focus is on the presence or absence of business disruption and recovery plans as a means of increasing a business's adaptation and resilience to flooding. Results show that some businesses, particularly small ones, are more likely to fail to recover from flooding due to lack of forward planning. Therefore from an ecological perspective business recovery post flooding is likely to be dependent upon ability to adapt, which itself depends upon the construction of resilient business environments.

Small-scale spatial distribution of oribatid mites has been investigated in Amazonia. In addition, medium- and large-scale studies are needed to establish the utility of these mites in detecting natural environmental variability, and to distinguish this variability from anthropogenic impacts. We are expanding the knowledge about oribatid mites in a wet upland forest reserve, and investigate whether a standardized and integrated protocol is an efficient way to assess the effects of environmental variables on their qualitative and quantitative composition on a large spatial scale inside an ecological reserve in Central Amazonia, Brazil. Samples for Berlese-Tullgren extraction were taken in 72 plots of 250 × 6 m distributed over 64 km(2). In total 3,182 adult individuals, from 82 species and 79 morphospecies were recorded, expanding the number of species known in the reserve from 149 to 254. Galumna, Rostrozetes and Scheloribates were the most speciose genera, and 57 species were rare. Rostrozetes ovulum, Pergalumna passimpuctata and Archegozetes longisetosus were the most abundant species, and the first two were the most frequent. Species number and abundance were not correlated with clay content, slope, pH and litter quantity. However, Principal Coordinate Analysis indicated that as the percentage of clay content, litter quantity and pH changed, the oribatid mite qualitative and quantitative composition also changed. The standardized protocol effectively captured the diversity, as we collected one of the largest registers of oribatid mites' species for Amazonia. Moreover, biological and ecological data were integrated to capture the effects of environmental variables accounting for their diversity and abundance.

We are summarizing the current state of knowledge of the diversity and distribution of oribatid mites in 26 environments in northern Brazil and of a rain forest in Peru. the published studies were mostly concentrated in central amazon. Only one report is a result from an agricultural polyculture. We are providing the first lists of species for savannas and for the brazilian states of Roraima and Pará. up to date, 146 species are definitively identified from a total of 444 taxa with 188 known genera, reinforcing the notion of a rich biodiverse area. the high number of 298 non-described species (morphospecies) clearly shows the inadequacy of the current taxonomic knowledge for the region. most of the registers are from forest environments. in the soil from primary forests, we registered the highest diversity (54-155 species/morphospecies). eighty-nine species were unique to primary forests, followed by 34 for savannas, 32 in trees, 10 in "igapó", 4 in caatinga, 3 in secondary forests, two in "várzea" and one in polyculture. twenty genera were the most speciose. the species with the largest home ranges were Rostrozetes foveolatus, Scheloribates sp. a, and Galumna sp. a. our numbers reflect the lack of taxonomists and show that the taxonomic knowledge must be improved for the region or we will continue to work with taxonomic resolution of order or family and a high percentage of morphospecies, which will probably be appropriate to the question being asked in each study, but not for a comparison among environments.

We analysed the community of oribatid mites in 25 environments of northern Brazil and one in a rain forest in Peru, encompassing fauna sampled on natural and artificial (nylon-mesh bags) substrata, from primary and secondary forests, caatinga, savannahs, flooded forests, bark and epiphytes of trees, and polyculture. A hundred and forty six species are definitively identified from a total of 444 taxa. To determine changes in the community, we took as a basis of comparison the species dominance of Lower Oribatida vs. Oppioidea and Lower Oribatida vs. Poronota. Even considering the different periods in which the inventories were realized and the different sampling methodology compared, the partition of the species of Oribatid mite in larger groups shows tendencies indicating partition of species dominance among the environments studied, showing that they differed in their suitability as habitats for the Oribatid mite community, mainly in respect to the Lower Oribatida, Oppioidea and Poronota composition. These tendencies should be explored in more detail as more becomes known about the species composition in each environment.

A new species, Chactas braziliensis sp. n., is described from Brazilian Amazonia. It can be distinguished from congeners by its small size, a generally darker coloration, a higher number of pectinal teeth, a totally smooth vesicle and its ecological preferences. The genus Chactas Gervais, 1844 is recorded for the first time for Brazil and the Amazon basin. The geographical pattern of its distribution is discussed.