| 1. |
- Householder, John Ethan, et al.
(författare)
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One sixth of Amazonian tree diversity is dependent on river floodplains
- 2024
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Ingår i: NATURE ECOLOGY & EVOLUTION. - 2397-334X.
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Tidskriftsartikel (refereegranskat)abstract
- Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.
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| 2. |
- Luize, Bruno Garcia, et al.
(författare)
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Geography and ecology shape the phylogenetic composition of Amazonian tree communities
- 2024
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Ingår i: JOURNAL OF BIOGEOGRAPHY. - 0305-0270 .- 1365-2699.
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and v & aacute;rzea forest types, the phylogenetic composition varies by geographic region, but the igap & oacute; and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R-2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R-2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions.
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| 3. |
- Calil, Wílerson Venceslau, et al.
(författare)
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Determining total cost of ownership and peak efficiency index of dynamically rated transformer at the PV-power plant
- 2024
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Ingår i: Electric power systems research. - : Elsevier BV. - 0378-7796 .- 1873-2046. ; 229
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Tidskriftsartikel (refereegranskat)abstract
- Dynamic rating of the transformer is a promising technology, which is suitable for various applications. Using dynamic rating for connecting renewable energy is believed to be beneficial for the economy and flexibility of the power system. However, to safely deploy such operation strategies, it is important to have more precise estimates for the total costs of owning such units and determine how effective such operation method is for a solar power plant. This study proposes a method for calculating total ownership costs (TOC) of dynamically rated transformers used for the connection of the solar power plant to the grid as well as analyzes its efficiency. The sensitivity analysis looks into the change in TOC and peak efficiency index (PEI) after considering reactive power dispatch. Results of this study also show how TOC, PEI, and load and no-load losses change depending on the transformer size.
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| 4. |
- Rosa, Augusto H.B., et al.
(författare)
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SYSTEMATIC POSITION AND CONSERVATION ASPECTS OF MELINAEA MNASIAS THERA (LEPIDOPTERA: NYMPHALIDAE: DANAINAE)
- 2024
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Ingår i: Nature Conservation Research. - 2500-008X. ; 9:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- The tribe Ithomiini (Nymphalidae: Danainae) includes nearly 400 species of butterflies distributed from Mex-ico to Northern Argentina, and adults of all species are aposematic and the main models in several Neotropical mimicry rings. The subtribe Melinaeina, a small group composed of five genera of large ithomiines, is the sister group of all remaining groups in the tribe Ithomiini. With 14 recognised species, the genus Melinaea is the most species rich, and also the most widespread within the Melinaeina. From all species of the genus, Melinaea mnasias is considered very rare and a little known one. This is also true for Melinaea mnasias thera, a subspecies from the Atlantic Forest with less than 20 specimens known in all world museums. Studies com-bining systematics, ecology, biogeography and natural history are priority in tropical areas, especially when focusing on threatened species. Thus, the aim of this study was to compile all available knowledge on the threatened M. mnasias thera, providing information to future management plans focusing on the conservation of this butterfly and its habitats. Data were compiled from scientific collections and personal observations, and the systematics of species of Melinaea was assessed by DNA sampling and analysis. The obtained phy-logeny recovered the subtribe Melinaeina organised in two clades, the first composed by Olyras + Paititia and the second by Eutresis + (Athyrtis + Melinaea). Melinaea mnasias thera was recovered as a sister to M. mnasias lucifer. A total of only 17 specimens of M. mnasias thera from four Brazilian localities were found in all revised collections. However, well-preserved forests are present only at one of these localities, in the southern Bahia state, from where a recent specimen has been collected, suggesting that the last populations of M. mnasias thera are restricted to this region. If this is true, the real conservation status of this species could be much more critical than the estimated.
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