•22 bee species were found visiting coffee flowers.•Forest cover positively affected native bee community at the shrub scale.•The presence of bees resulted in an increase in coffee fruit set of ...28%.•Apis mellifera abundance positively affected fruit set across spatial scales.•Native bee community affected fruit set differently at different scales.
Although several studies have shown that the presence of bees results in increased crop yields, the mechanisms that determine pollination service across different spatial scales are still largely unknown. Here, we evaluated the influence of landscape structure over bee community composition and coffee (Coffea arabica) pollination. Our study was undertaken in one of the most important coffee-producing regions of Brazil, and comprised nine landscapes of sun coffee plantations surrounded by different amounts of Atlantic Forest remnants. Using floral exclusion experiments we evaluated fruit set in 15 coffee shrubs per landscape. We also sampled the bees visiting coffee flowers. Our analyses were made at two landscape scales, with 1 and 2km radii, and one shrub scale, with 300m radius around each coffee shrub. We collected 241 bee individuals and identified a total of 22 species. The honeybee Apis mellifera (Apini) was the most abundant flower visitor followed by Trigona spinipes (Meliponini). Native bee abundance, richness and diversity were positively affected by forest cover at the shrub scale. Honeybee abundance, on the other hand, was negatively affected by forest cover at the shrub scale. The presence of bees resulted in an increase in coffee fruit set of 28%. A. mellifera abundance positively affected fruit set across spatial scales, while the composition of the native bee community affected fruit set differently at the landscape scales than at the shrub scale. Our work shows that bee pollination services are affected by landscape structure at different spatial scales. These findings can be used in conservation and agricultural planning to maximize crop production while safeguarding biodiversity and the provision of pollination services.
Abstract A system called QUALIS was implemented in Brazil in 2009, intended to rank graduate programs from different subject areas and promote selected national journals. Since this system uses a ...complicated suit of criteria (differing among subject areas) to group journals into discrete categories, it could potentially create incentives to publish in low-impact journals ranked highly by QUALIS. Here I assess the influence of the QUALIS journal ranking system on the global impact of Brazilian science. Brazil shows a steeper decrease in the number of citations per document since the implementation of this QUALIS system, compared to the top Latin American countries publishing more scientific articles. All subject areas showed some degree of bias, with social sciences being usually more biased than natural sciences. Lastly, the decrease in the number of citations over time proved steeper in a more biased subject area, suggesting a faster shift towards low-impact journals. Overall, the findings documented here suggest that the QUALIS system has undermined the global impact of Brazilian science, and reinforce a recent recommendation from an official committee evaluating graduate programs to eliminate QUALIS. A system based on impact metrics could avoid introducing distorted incentives, and thereby boost the global impact of Brazilian science.
The highly social (eusocial) corbiculate bees, comprising the honey bees, bumble bees, and stingless bees, are ubiquitous insect pollinators that fulfill critical roles in ecosystem services and ...human agriculture. Here, we conduct wide sampling across the phylogeny of these corbiculate bees and reveal a dynamic evolutionary history behind their microbiota, marked by multiple gains and losses of gut associates, the presence of generalist as well as host-specific strains, and patterns of diversification driven, in part, by host ecology (for example, colony size). Across four continents, we found that different host species have distinct gut communities, largely independent of geography or sympatry. Nonetheless, their microbiota has a shared heritage: The emergence of the eusocial corbiculate bees from solitary ancestors appears to coincide with the acquisition of five core gut bacterial lineages, supporting the hypothesis that host sociality facilitates the development and maintenance of specialized microbiomes.
Context
As agricultural demands for land continues to expand, strategies are urgently needed to balance agricultural production with biodiversity conservation and ecosystem service provision in ...agricultural landscapes.
Objectives
We used a factorial landscape design to assess the relative contributions of forest proximity and local forest cover to bee diversity and the provision of coffee pollination services.
Methods
We quantified bee diversity and fruit set in 24 sun-grown coffee fields in Southeast Region of Brazil that were selected following a factorial sampling design to test the independent effects of local forest cover (in a radius of 400 m) and proximity to forest fragments. To assess the impact of landscape simplification, we also evaluated local coffee cover.
Results
Bee richness and abundance were higher in the proximity of forest fragments, but only bee abundance decreased when the coffee cover dominated the surrounding landscapes. Coffee fruit set was 16% higher overall with bee visitations compared with bee exclusion and increased to 20% when coffee bushes were near forest fragments, and the coffee cover was low. Surprisingly, local forest cover did not affect the bee community or coffee fruit set.
Conclusion
Our results provide clear evidence that the proximity of coffee crops to forest fragments can affect the abundance and richness of bees visiting the coffee flowers and thereby facilitate the provision of pollination services. The positive association between forest proximity and fruit set reinforces the importance of natural vegetation in enhancing bee diversity and, therefore, in the provision of pollination services. The negative effect of coffee cover on fruit set at the local scale suggests that the service demand can surpass the capacity of pollinators to provide it. These effects were independent of the local forest cover, although all studied landscapes had more than 20% remaining forest cover (within a 2 km radius), which is considered the extinction threshold for Atlantic Forest species. Interspersion of forest fragments and coffee plantations in regions with more than 20% of forest cover left could thus be a useful landscape management target for facilitating pollinator flows to coffee crops and thus for increasing coffee yields.
Europe harbours several endemic honeybee (
Apis mellifera
) subspecies. Yet the distribution of these subspecies is nowadays also much influenced by beekeeping activities. Large scale migratory ...beekeeping and trade in queens, coupled with the promiscuous mating system of honeybees, have exposed native European honeybees to increasing introgressive hybridization with managed non-native subspecies, which may lead to the loss of valuable combinations of traits shaped by natural selection. Other threats to European honeybees are factors that have caused a progressive decline in
A. mellifera
throughout the world in recent years, leading to large economic losses and jeopardizing ecosystem functioning. We review the biodiversity of European honeybees and summarize the management and conservation strategies employed by different countries. A comprehensive picture of the beekeeping industry in Europe is also provided. Finally we evaluate the potential threats affecting the biodiversity of European honeybee populations and provide some perspectives for future research.
Context
Island Biogeography Theory and Habitat Amount Hypothesis postulate species richness and densities to increase with connectivity and habitat amount, while niche theory highlights the ...importance of environmental heterogeneity for species coexistence. Additional ecological niches in heterogeneous landscapes increase species richness and functional and phylogenetic diversity, but larger, less isolated habitats are expected to enlarge species densities by mass effects without effects on functional or phylogenetic diversity.
Objectives
We assessed the relative contribution of habitat amount, isolation and environmental heterogeneity on taxonomic, functional and phylogenetic diversity of the particular
canga
vegetation, i.e., rupestrian savannas associated to banded ironstone outcrops from the Carajás Massif, Eastern Amazon.
Methods
We sampled vegetation at 48 sampling points comprising different physiognomies from 5
canga
patches. Diversity measures were modelled as response variables in linear mixed models, using non-collinear predictors of habitat amount, isolation and environmental heterogeneity.
Results
Diversity and species composition differed among
canga
physiognomies, indicating that environmental filters segregate
canga
plant metacommunity in physiognomy-specific species pools. Landscape roughness, a proxy for heterogeneity on the landscape level, increases species densities and functional richness. Additionally, habitat amount was positively associated with the degree of phylogenetic relatedness and functional diversity in communities.
Conclusions
Our results suggest that configurational landscape heterogeneity increases the number of available ecological niches, while larger habitat amounts select for functionally and phylogenetically convergent species. These different underlying mechanisms need to be considered for management plans and reserve design for
canga
ecosystems, so that functional
canga
portions can be protected.
The regeneration of disturbed forest is an essential part of tropical forest ecology, both with respect to natural disturbance regimes and large-scale human-mediated logging, grazing, and ...agriculture. Pioneer tree species are critical for facilitating the transition from deforested land to secondary forest because they stabilize terrain and enhance connectivity between forest fragments by increasing matrix permeability and initiating disperser community assembly. Despite the ecological importance of early successional species, little is known about their ability to maintain gene flow across deforested landscapes. Utilizing highly polymorphic microsatellite markers, we examined patterns of genetic diversity and differentiation for the pioneer understory tree Miconia affinis across the Isthmus of Panama. Furthermore, we investigated the impact of geographic distance, forest cover, and elevation on genetic differentiation among populations using circuit theory and regression modeling within a landscape genetics framework. We report marked differences in historical and contemporary migration rates and moderately high levels of genetic differentiation in M. affinis populations across the Isthmus of Panama. Genetic differentiation increased significantly with elevation and geographic distance among populations; however, we did not find that forest cover enhanced or reduced genetic differentiation in the study region. Overall, our results reveal strong dispersal for M. affinis across human-altered landscapes, highlighting the potential use of this species for reforestation in tropical regions. Additionally, this study demonstrates the importance of considering topography when designing programs aimed at conserving genetic diversity within degraded tropical landscapes.
Increasing the connectivity of protected areas is an urgent need to ensure the conservation of forest species and help them to shift their ranges due to anthropogenic drivers. However, efforts to do ...so considering the joint effects of habitat fragmentation and climate change are still scant. Here, we aimed to outline a framework that incorporates spatial, temporal and multi-taxa criteria to pinpoint locations that connect protected areas in the eastern Amazon. We analyzed three mosaics of protected areas, and data on 603 species (bees, birds, bats) and developed two models using species movement flow (MF; through circuit theory) and habitat suitability (HS; through species distribution models). Considering only the MF, northward areas are the main candidates for corridors, most of which presenting forest cover (68% of the 928,379 ha). This result changes when we analyze the HS, since the corridors are mostly positioned in a different direction (westward) and less than half have forest cover (45% of the 925,058 ha). Candidate areas for both approaches totaled 135,171 ha, with 86% still covered by forest. Our results rely on methodological and taxonomic redundancy (to depict a range of movement and/or habitat requirements) for an efficient strategy to prioritize areas for connectivity. Dynamic restoration simulations showed that the location and order of restoration are important to ensure increased availability of habitat. Our approach can help address two important biodiversity threats (habitat loss and climate change) and maximize the selection of the best corridors to protect species in a rapidly changing world.
•Increasing connectivity between protected areas is urgent to promote conservation•Corridors rely on landscape structure, climate change and species dispersal ability•We offer a useful approach for local initiatives aiming to protect tropical forests•Our approach uses the best available data and is flexible to refinement
Pollination services are increasingly threatened by the loss and modification of natural habitats, posing a risk to the maintenance of both native plant biodiversity and agricultural production. In ...order to safeguard pollination services, it is essential to examine the impacts of habitat degradation on the population dynamics of key pollinators and identify potential “rescue pollinators” capable of persisting in these human-altered landscapes. Using a landscape genetic approach, we assessed the impact of landscape structure on genetic differentiation in the widely-distributed tropical stingless bee Trigona spinipes (Apidae: Meliponini) across agricultural landscape mosaics composed of coffee plantations and Atlantic forest fragments in southeastern Brazil. We genotyped 115 bees at 16 specific and highly polymorphic microsatellite loci, developed using next-generation sequencing. Our results reveal that T. spinipes is capable of dispersing across remarkably long distances, as we did not find genetic differentiation across a 200 km range, nor fine-scale spatial genetic structure. Furthermore, gene flow was not affected by forest cover, land cover, or elevation, indicating that reproductive individuals are able to disperse well through agricultural landscapes and across altitudinal gradients. We also found evidence of a recent population expansion, suggesting that this opportunistic stingless bee is capable of colonizing degraded habitats. Our results thus suggest that T. spinipes can persist in heavily-altered landscapes and can be regarded as a rescue pollinator, potentially compensating for the decline of other native pollinators in degraded tropical landscapes.
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