| 1. |
- Oliveira, Helena Rodrigues, et al.
(author)
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Biogas potential of biowaste: A case study in the state of Rio de Janeiro, Brazil
- 2024
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In: Renewable energy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0960-1481 .- 1879-0682. ; 221
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Journal article (peer-reviewed)abstract
- Anaerobic digestion has been widely applied for waste treatment, renewable energy generation , biofertilizer production. The biogas potential in Brazil is sizable, but the state of Rio de Janeiro is largely dependent on fossil fuels , there is a lack of biogas potential assessments in the state. Thus, this study evaluated biomethane, electricity and biofertilizer potentials in the region. Three different scenarios of biomass supply were considered for four major biowaste streams: sewage sludge; cattle manure; sugarcane processing waste; and food waste. Biomethane generation from the assessed sources could reach 0.6-1.3 billion Nm(3) year(-1), corresponding to 1,768-3,961 GWh year(-1) of electricity , 1.6-3.3 million Mg year- 1 of biofertilizer. Cattle manure was responsible for 73-84% of the projected biomethane production, presenting an opportunity to reduce the sig-nificant emissions from livestock farming. The estimated biofertilizer production could meet the demands of the state , the produced electricity could offset up to 10% of the demand. The gas grid could facilitate the dis-tribution of upgraded biomethane, and 10-22% of the natural gas demand could be met. The findings of this work highlight the high potential for biogas generation in Rio de Janeiro, which is up to seven times larger than the current production.
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| 2. |
- Alves-Martins, Fernanda, et al.
(author)
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Drivers of regional and local diversity of Amazonian stream Odonata
- 2019
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In: Insect Conservation and Diversity. - : Wiley-Blackwell. - 1752-458X .- 1752-4598. ; 12:3, s. 251-261
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Journal article (peer-reviewed)abstract
- Large Amazonian rivers may act as dispersal barriers for animals with low dispersal abilities, limiting their distribution to certain interfluves. Consequently, the distribution of these taxa would be less affected by macroclimatic gradients. Conversely, high-dispersal taxa would be less constrained by large rivers and may track suitable climates. We evaluate whether Zygoptera and Anisoptera, two Odonata suborders with different dispersal abilities, show differences in distribution patterns across Amazonian interfluves. We further assess the relative importance of macroclimatic and habitat factors in their community assembly. We used network modularity analyses to identify biogeographic species pools and spatial buffers to define metacommunity species pools. Then, we used structural equationmodels to estimate the relative importance of multi-scale factors on species richness patterns. Zygoptera communities are more similar in species composition within than between interfluves, suggesting that large Amazonian rivers indeed limit the distribution of Zygoptera species. Conversely, the distribution of Anisoptera extends across Amazonian interfluves. Seasonality has a strong positive effect on Zygoptera and Anisoptera richness across scales. In addition, habitat integrity is negatively correlated with the regional species richness and abundance of Anisoptera and positively correlated with Zygoptera local richness. The contrasting effects of habitat integrity on Anisoptera and Zygoptera suggest that the former is favored in open habitats, whereas the latter is so in forests. Despite these differences, both suborders appear to follow similar community assembly mechanisms in Amazonia, with a strong climatic control across scales and an effect of habitat filters on local communities.
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| 3. |
- Calatayud, Joaquín, et al.
(author)
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Positive associations among rare species and their persistence in ecological assemblages
- 2020
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In: Nature Ecology & Evolution. - : Nature Publishing Group. - 2397-334X. ; 4:1, s. 40-45
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Journal article (peer-reviewed)abstract
- According to the competitive exclusion principle, species with low competitive abilities should be excluded by more efficient competitors; yet, they generally remain as rare species. Here, we describe the positive and negative spatial association networks of 326 disparate assemblages, showing a general organization pattern that simultaneously supports the primacy of competition and the persistence of rare species. Abundant species monopolize negative associations in about 90% of the assemblages. On the other hand, rare species are mostly involved in positive associations, forming small network modules. Simulations suggest that positive interactions among rare species and microhabitat preferences are the most probable mechanisms underpinning this pattern and rare species persistence. The consistent results across taxa and geography suggest a general explanation for the maintenance of biodiversity in competitive environments. Analysing spatial association networks among >300 terrestrial and aquatic assemblages, the authors find that the majority of negative associations involve abundant species. In contrast, rare species form mostly positive associations, potentially explaining their persistence in natural communities.
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| 4. |
- Cordeiro, Guaraci D., et al.
(author)
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Nocturnal bees as crop pollinators
- 2021
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In: agronomy. - : MDPI AG. - 2073-4395. ; 11:5
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Journal article (peer-reviewed)abstract
- Bees are typically diurnal but around 1% of described species have nocturnal activity. Nocturnal bees are still poorly studied due to bias towards studying diurnal insects. However, knowledge concerning their biology and role as crop pollinators has increased. We review the literature on nocturnal bees’ traits and their host plants, and assess the crop pollination effectiveness of this neglected group. Nocturnal bees have visual adaptations to cope with low light intensities, and floral scents are a key sensory cue used to find their host flowers. Nocturnal bees generally show high flower constancy, the ability to vibrate flowers, and high transfer rates of pollen grains to stigmas. The flowers visited by nocturnal bees range from small radial and zygomorphic flowers to large brush blossoms; moreover, they visit plants with different flowering strategies. Nocturnal bees are effective pollinators of regional fruit crops in Brazil, such as cambuci (Campomanesia phaea), guaraná (Paullinia cupana), cajá (Spondias mombin), and in North America of cultivated pumpkins (Cucurbita species). However, they most likely are pollinators of several other crops. Strategies to host high numbers of nocturnal bees around cropping areas should be taken, such as preserving adjacent native forests, restricting soil management, providing food resources beyond crop flowers, and avoiding light pollution.
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