Forest patch isolation drives local extinctions of Amazonian orchid bees in a 26 years old archipelago

Major hydroelectric dams are among key emergent agents of habitat loss and fragmentation in lowland tropical forests. Orchid bees (Apidae, Euglossini) are one of the most important groups of specialized pollinators of flowering plants in Neotropical forests. Here, we investigate how an entire assemblage of orchid bees responded to the effects of forest habitat loss, isolation and forest canopy degradation induced by a hydroelectric reservoir of Central Brazilian Amazonia. Built in 1986, the Balbina Dam resulted in a vast archipelagic landscape containing 3546 primary forest islands of varying sizes and isolation, surrounded by 3129 km2 of freshwater. Using scent traps, we sampled 34 islands, 14 open-water matrix sites, and three mainland continuous forests, yielding 2870 male orchid bees representing 25 species. Local orchid bee species richness was affected by forest patch area but particularly by site isolation. Distance to forest edges, either within forest areas or into the open-water matrix, was the most important predictor of species richness and composition. Variation in matrix dispersal of individual species to increasingly isolated sites was a key determinant of community structure. Given the patterns of patch persistence and matrix movements of orchid bees in increasingly fragmented forest landscapes, we outline how forest bees respond to the landscape alteration induced by major hydroelectric dams. These results should be considered in environmental impact studies prior to the approval of new dams

Effects of forest degradation on Amazonian ferns in a land-bridge island system as revealed by non-specialist inventories

Tropical forests have been rapidly deforested and degradation worldwide has outpaced biodiversity field sampling. No study to date has assessed the effects of insular habitats induced by hydroelectric dams on Amazonian understory plants. Fern community responses to anthropogenic effects on tropical forest islands can be revealed at a faster pace by using simple and cheap, yet informative, protocols that could be applied by non-specialists. This study seeks to both understand the drivers of fern and lycophytes assemblages on forest islands and investigate the relative costs and effectiveness of a simplified sampling protocol that can be applied by non-specialists. Fern species were sampled by a non-specialist who photographed all ferns and lycophytes within seventeen 0.25-ha plots on 10 forest islands at the lake of Balbina Hydroelectric dam, central Amazonia. Sampling was carried out opportunistically during a field expedition planned to conduct tree inventories. As predictors, we used locally measured or GIS-derived descriptors of plot and landscape conditions. We used multivariate and linear models to further assess the influence of predictors on patterns of species richness and composition of ferns assemblages. A total of 286 photographed individual ferns or lycophytes represented at least 23 species and 14 genera. The average number of taxa per plot was 6.1 in the islands and 14.3 in the mainland. The species pool found on islands was a nested subset of the mainland fern community. Species richness was positively related to island size and negatively related to isolation and fire severity. Area, isolation and fire severity also significantly explained variation in community composition. The relative cost of the picture-based fern protocol applied was very modest (only 4% of the total expedition budget), even compared to the typically low cost of alternative field campaigns. We conclude that fern community structure in this forest archipelago was primarily driven by island size, isolation and fire disturbance. Moreover, we show that a simple sampling protocol carried out by a non-specialist can lead to inexpensive and highly reliable ecological data. This opens an avenue for crowdsourcing ecological fern data collections using a citizen science approach.</p

Effects of forest degradation on Amazonian ferns in a land‐bridge island system as revealed by non‐specialist inventories

Tropical forests have been rapidly deforested and degradation worldwide has outpaced biodiversity field sampling. No study to date has assessed the effects of insular habitats induced by hydroelectric dams on Amazonian understory plants. Fern community responses to anthropogenic effects on tropical forest islands can be revealed at a faster pace by using simple and cheap, yet informative, protocols that could be applied by non-specialists. This study seeks to both understand the drivers of fern and lycophytes assemblages on forest islands and investigate the relative costs and effectiveness of a simplified sampling protocol that can be applied by non-specialists. Fern species were sampled by a non-specialist who photographed all ferns and lycophytes within seventeen 0.25-ha plots on 10 forest islands at the lake of Balbina Hydroelectric dam, central Amazonia. Sampling was carried out opportunistically during a field expedition planned to conduct tree inventories. As predictors, we used locally measured or GIS-derived descriptors of plot and landscape conditions. We used multivariate and linear models to further assess the influence of predictors on patterns of species richness and composition of ferns assemblages. A total of 286 photographed individual ferns or lycophytes represented at least 23 species and 14 genera. The average number of taxa per plot was 6.1 in the islands and 14.3 in the mainland. The species pool found on islands was a nested subset of the mainland fern community. Species richness was positively related to island size and negatively related to isolation and fire severity. Area, isolation and fire severity also significantly explained variation in community composition. The relative cost of the picture-based fern protocol applied was very modest (only 4% of the total expedition budget), even compared to the typically low cost of alternative field campaigns. We conclude that fern community structure in this forest archipelago was primarily driven by island size, isolation and fire disturbance. Moreover, we show that a simple sampling protocol carried out by a non-specialist can lead to inexpensive and highly reliable ecological data. This opens an avenue for crowdsourcing ecological fern data collections using a citizen science approach

Checklist of orchid bees (hymenoptera: Apidae) of "Lago do Silêncio" area, Boca do Acre, Amazonas, Brazil

This study presents a list of euglossine-bee species collected in the Lago do Silêncio region, municipality of Boca do Acre, in the Brazilian state of Amazonas, southwestern Amazonia. Euglossine males were attracted to odoriferous baits on December 3 and 4, 2004. A total of 234 individuals belonging to four genera and 25 species were collected. Despite the small sampling effort, the local euglossine fauna is abundant and rich, when compared to those of other areas in the Brazilian Amazonia where higher sampling efforts were performed. Therefore, further studies in the region can be important for improving our knowledge of the bees in the Amazon region. © 2011 Check List and Authors

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

Can Baited Pitfall Traps for Sampling Dung Beetles Replace Conventional Traps for Sampling Ants?

Ants  and  dung  beetles  are  widely  used  in  monitoring  biodiversity  and  are  considered  excellent  environmental  indicators.  Although  the pitfall trap is the most commonly used method to sample dung beetles and ants in ecological studies, beetles are usually sampled using dung‐baited pitfall traps while ants are sampled using un‐baited pitfalls. In the protocol for collecting the beetles it is necessary to have attractive baits in pitfalls. In order to minimize collection effort and costs and to facilitate logistics, it is necessary to determine if there is an effect of the baits on the biodiversity of ants collected in the same traps. Therefore, the objective of this work was to find out whether baited pitfalls could replace conventional pitfalls for the capture of ants. In a total of 42 areas of native habitat, three baited pitfall traps and three without bait were installed, all in the same transect, equidistant ten meters and in activity for 48 hours. In total, 150 species were collected, of which 131 were recorded in non‐baited pitfalls and 107 in baited pitfalls. Traps without bait contributed to 28% of the total number of species captured in this study, whereas pitfalls with bait contributed only to 12% of the total species caught. However, 60% of the total species were captured regardless of the method. In addition to the loss of species among the types of traps, the effect of the method modifies the species composition. We concluded that depending on the type of study, a small decrease in the number of species and change in the composition can influence the results. Thus, we recommend that baited pitfalls should not replace conventional pitfalls.Palavras-chave: Método de coleta; Protocolo de coleta; Desenho da amostra; Esforço de amostragem

INFLUENCE OF LAND USE AND OCCUPATION IN THE QUALITY OF SURFACE WATER IN THE PARAGUAI / DIAMANTINO BASIN, MATO GROSSO, BRAZIL

This study aims to evaluate the influence of land use and occupation at diferente scales on the quality of surface water of the Paraguay/Diamantino basin, Mato Grosso State, Brazil. Statistical tests were used to verify if there is a difference between scales at each point. Land use and land occupation analysis was performed using images from the RapidEye satellite. An unsupervised classification of the images was performed, and hree classes of land use were defined: Evergreen Seasonal Forest, Cerrado and Anthropic Uses. Using ArcGIS software, the scales were defined using the multibuffer tool with radius of 50, 500 and 1000 meters in the vicinity of each sample point. The sample collections were of the simple type, on surface in 9 points of the main tributaries of the basin. ANOVA indicated a significant difference of turbidity in the rain and drought periods, which did not occur with the Total Solids. The analysis indicated a negative correlation between total Solids and the Evergreen Seasonal Forest class. They also showed a similarity in relation to Total Solids and Turbidity, being influenced by the spatial distance between the point

Contribution of the Cerrado as Habitat for Sunflower Pollinating Bees

Agricultural landscapes sometimes include natural habitats which can support the ecosystem by enhancing the pollination of crops, thus boosting the productivity. This research was conducted between May and July 2017, in the municipality of Tangará da Serra, Mato Grosso, Brazil, to assess the Cerrado from the perspective of it being a crucial habitat to sustain the sunflower-pollinating bees (Helianthus annuus L.). The bees were sampled using entomological nets and pan traps, in specifically marked out plots (20 m x 150 m), in the Cerrado, and in a sunflower crop, at different distances from the Cerrado border. The assessment was done in terms of the composion and species richness, abundance of individuals and the mass (g) of the sunflower chapters exposed and isolated from the floral visitors. While species richness showed no differences between the Cerrado and sunflower crop, a difference was observed for abundance, with more numbers of individuals in the sunflower crop, most likely because of the food source supply. In the sunflower crop, the bee diversity decreased proportionally as the distance from the border increased. The seed mass of the sunfl ower chapters was significantly higher in the flowers open to visitors than in those of the isolated chapters open for visitation. From the results, it was evident that the bees presente in the Cerrado visit the sunflower crop to gather pollen and nectar, and thus assist in cross-pollinating them and raising the productivity

Using relict species-area relationships to estimate the conservation value of reservoir islands to improve environmental impact assessments of dams

Large dams are emerging drivers of landscape-scale habitat fragmentation, causing extensive flooding and transforming hilltops into islands. Environmental Impact Assessments (EIAs; the process to assess and account for impacts of development) do not explicitly consider reservoir islands in calculations of habitat impacted by dam construction. Reservoir islands maintain relict biological communities from the previously continuous habitat. Relict communities are subject to an extinction debt whereby species are lost over time. We demonstrate how estimating the ‘conservation value’ of islands (CV; the proportion of relict continuous habitat [forest] species on islands) using relict species–area relationships (RSARs), can be used in an area-of-impact correction tool to account for insular habitats in EIAs. We used data from eight taxonomic groups within the Balbina Hydroelectric Reservoir (BHR) archipelago in Brazilian Amazonia. We found ca. 72,000 ha of insular habitat had reduced CV, equating to 60% of aggregate island area, and that an additional 24% of the ca. 300,000 ha BHR water surface area should be included in area assessments for impacted terrestrial habitat. Where reservoir island creation is unavoidable, using RSARs to assess the CV of islands enables more accurate and dynamic assessment of the ecological impacts of dam construction

Biodiversity responses to insular fragmentation in Amazonia: two decades of research in the Balbina Hydroelectric Reservoir

As hydropower development expands across lowland tropical forests, flooding and concomitant insular fragmentation have become important threats to biodiversity. Newly created insular landscapes serve as natural laboratories to investigate biodiversity responses to fragmentation. One of these most iconic landscapes is the Balbina Hydroelectric Reservoir in Brazilian Amazonia, occupying >400 000 ha and comprising >3 500 forest islands. Here, we synthesise the current knowledge on responses of a wide range of biological groups to insular fragmentation at Balbina. Sampling has largely concentrated on a set of 22 islands and three mainland sites. In total, 39 studies were conducted over nearly two decades, covering 17 vertebrate, invertebrate, and plant taxa. Although species responses varied according to taxonomic group, island area was consistently included and played a pivotal role in 66.7% of all studies examining patterns of species diversity. Species persistence was further affected by species traits, mostly related to species capacity to use/traverse the aquatic matrix or tolerate habitat degradation, as noted for species of vertebrates and orchid bees. Further research is needed to improve our understanding of such effects on wider ecosystem functioning. Environmental Impact Assessments must account for changes in both the remaining habitat amount and configuration, and subsequent long-term species losses