| 1. |
- Diele-Viegas, L. M., et al.
(författare)
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Community voices: sowing, germinating, flourishing as strategies to support inclusion in STEM
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Understanding gaps in academic representation while considering the intersectionality concept is paramount to promoting real progress towards a more inclusive STEM. Here we discuss ways in which STEM careers can be sown and germinated so that inclusivity can flourish.
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| 2. |
- Cássia-Silva, C., et al.
(författare)
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Niche conservatism drives a global discrepancy in palm species richness between seasonally dry and moist habitats
- 2019
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 28:6, s. 814-825
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Rapid global environmental change predicts increasingly seasonal climate in the tropics, causing expansion of seasonally dry habitats and leading to shifts in species distribution and potential extinction. Here, we use a macroevolutionary framework to understand the processes driving palm diversity patterns between moist and seasonally dry tropical habitats. We hypothesize that the discrepancy in species richness between habitats is explained by higher speciation rates in moist habitat and that niche conservatism prevents frequent shifts between habitats. Location: Global. Time period: Last 100Ma. Major taxa studied: Arecaceae. Methods: We used trait-dependent diversification models to test whether different habitats affect palm speciation rates. Furthermore, palm assemblages were divided into three regions (Africa, Australasia and Neotropics) to test for niche conservatism and evaluate phylogenetic dissimilarity. Results: We found no relationship between speciation rate and habitat type. We detected phylogenetic signal for habitats at both global and continental scales, indicating that closely related species were more similar than expected by chance. Colonization of seasonally dry habitats occurred c.60Ma, yet most clades only diversified after c.30Ma. The high phylogenetic dissimilarity between habitat types at both global and continental scales was driven by high lineage turnover, at least for Africa and the Neotropics. Main conclusions: We found a lack of differential speciation rates in setting the seasonally dry and moist palm-richness discrepancy. However, over evolutionary history most palm lineages fail to colonize seasonally dry habitats owing to a tendency to retain ancestral habitat. Indeed, seasonally dry palm assemblages are the result of the diversification of particular lineages. Likewise, long-term dry periods appear to induce shifts in taxonomic and functional diversity, and we emphasize that the expansion of dry habitats might also imply a loss of palm clades, hence a reduction in phylogenetic diversity. © 2019 John Wiley & Sons Ltd
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| 3. |
- Cassia-Silva, C., et al.
(författare)
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Acaulescence promotes speciation and shapes the distribution patterns of palms in Neotropical seasonally dry habitats
- 2022
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Ingår i: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Rainforests have been a source of lineages to open and seasonally dry habitats throughout Angiosperm evolution, especially in the Neotropics. However, the underlying mechanisms that allow such shifts remain poorly understood at large spatial scales. Here, we test whether acaulescence (an underground stem or a very short stem concealed in the ground) has affected the colonization and speciation in Neotropical seasonally dry habitats by cocosoid palms (Cocoseae). Acaulescent species maintain their growth underground, which increases their chances of survival from prolonged seasonal dry season and frequent fires. We use an integrative approach based on trait-dependent diversification models, phylogenetic comparative methods and ecological niche models. We found that shifts towards acaulescent growth form were accompanied by evolutionary transitions to seasonally dry habitats. Acaulescent lineages had higher speciation rates than non-acaulescent ones. However, the interaction between acaulescence and seasonally dry habitats had no significant effect on Cocoseae speciation rates. Acaulescent palms are primarily distributed in Neotropical seasonally dry habitats and non-acaulescent palms are concentrated in Amazonian rainforests. Our results suggest that an underground stem, with high carbohydrate and water storage capacity, is a preadaptation by which rainforest lineages were able to colonize and diversify in new fire-prone, increasingly seasonal and drier adaptive zones. The projected global expansion of dry seasonal habitats requires an understanding of how drought-avoidance functional traits evolve and how they are linked to seasonally dry habitats. Our results are, thus, a step forward in determining plant response mechanisms to drier and seasonal conditions.
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| 4. |
- Cássia-Silva, C., et al.
(författare)
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Higher evolutionary rates in life-history traits in insular than in mainland palms
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Isolated islands, due to the reduced interspecific competition compared to mainland habitats, present ecological opportunities for colonizing lineages. As a consequence, island lineages may be expected to experience higher rates of trait evolution than mainland lineages. However, island effects on key life-history traits of vascular plants remain underexplored at broad spatiotemporal scales, even for emblematic island clades such as palms. Here, we used phylogenetic comparative methods to evaluate potential differences in size and macroevolutionary patterns of height and fruit diameter among mainland, continental, and volcanic island palms. Further, phylogenetic beta-diversity was used to determine if lineage turnover supported an adaptive radiation scenario on volcanic islands. Volcanic island palms were taller than their continental island and mainland counterparts, whereas continental island palms exhibited smaller fruit size. Height and fruit size of palms evolved under evolutionary constraints towards an optimal value. However, scenarios of adaptive radiation and niche conservatism were not supported for the height and fruit size of volcanic and mainland palm clades, respectively, as expected. Instead, continental island palms exhibited higher evolutionary rates for height and fruit size. Insular palm assemblages (continental and volcanic) are composed of unique lineages. Beyond representing evolutionary sources of new palm lineages, our results demonstrate that insular habitats are important in shaping palm trait diversity. Also, the higher phenotypic evolutionary rates of continental island palms suggest disparate selection pressures on this habitat type, which can be an important driver of trait diversification over time. Taken together, these results stress the importance of insular habitats for conservation of functional, phylogenetic, and taxonomic diversity of palms. © 2020, The Author(s).
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| 5. |
- Freitas, C., et al.
(författare)
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Incongruent Spatial Distribution of Taxonomic, Phylogenetic, and Functional Diversity in Neotropical Cocosoid Palms
- 2021
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Ingår i: Frontiers in Forests and Global Change. - : Frontiers Media SA. - 2624-893X. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Biodiversity can be quantified by taxonomic, phylogenetic, and functional diversity. Current evidence points to a lack of congruence between the spatial distribution of these facets due to evolutionary and ecological constraints. A lack of congruence is especially evident between phylogenetic and taxonomic diversity since the name and number of species are an artificial, yet commonly used, way to measure biodiversity. Here we hypothesize that due to evolutionary constraints that link phylogenetic and functional diversity, areas with higher phylogenetic and functional diversity will be spatially congruent in Neotropical cocosoid palms, but neither will be congruent with areas of high taxonomic diversity. Also, we hypothesize that any congruent pattern differs between rainforests and seasonally dry forests, since these palms recently colonized and diversified in seasonally dry ecosystems. We use ecological niche modeling, a phylogenetic tree and a trait database to test the spatial congruence of the three facets of biodiversity. Taxonomic and phylogenetic diversity were negatively correlated. Phylogenetic and functional diversity were positively correlated, even though their spatial congruence was lower than expected at random. Taken together, our results suggest that studies focusing solely on large-scale patterns of taxonomic diversity are missing a wealth of information on diversification potential and ecosystem functioning.
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| 6. |
- Cassia-Silva, C., et al.
(författare)
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Uneven patterns of palm species loss due to climate change are not driven by their sexual systems
- 2023
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Ingår i: Biodiversity and Conservation. - 0960-3115. ; 32:13, s. 4353-69
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Tidskriftsartikel (refereegranskat)abstract
- As plants are sessile organisms, their response to environmental change may be mechanistically mediated by reproductive traits. The spatial segregation and physiological specialization of the sexes in dioicous plants, for instance, create mismatches in individual responses to environmental change. Conversely, the ability of self-fertilization circumvents the need for sexual partners and has been linked to the dominance of hermaphrodites in habitats with drought stress. Sexual systems (dioecy, hermaphroditism, monoecy, and polygamy) are key drivers of plant distribution, which raises the question of how they will respond to climate change. Here, we leverage the diversity of the sexual systems of palms (Arecaceae) to test their role on species distribution potential under climate change, comparing distribution patterns among biogeographic realms. Additionally, we evaluated how climate change will affect the palm richness patterns worldwide. We fitted ecological niche models to species' occurrence and climate and soil data from present-day conditions, then projected onto climate change projections referred to years 2050 and 2090. We found that different sexual systems of palms respond similarly to climate change, with reductions in potential distribution expected for all sexual systems. Most species (354 out of 540) are expected to lose suitable areas, particularly in Neotropics, where palm richness is concentrated. Sharp richness loss is projected for Amazonia and Neotropical savanna - Cerrado, which can lose up to 50 and 40 palms, respectively. As sexual systems responded similarly to climate change, their role in species' response to climate change remains elusive. Our work does show that threats of climate change to global palm richness are ubiquitous, yet uneven geographically.
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| 7. |
- Hill, Adrian, et al.
(författare)
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Apparent effect of range size and fruit colour on palm diversification may be spurious
- 2023
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Ingår i: Journal of Biogeography. - 0305-0270. ; 50:10, s. 1724-1736
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Tidskriftsartikel (refereegranskat)abstract
- Aim Fruit selection by animal dispersers with different mobility directly impacts plant geographical range size, which, in turn, may impact plant diversification. Here, we examine the interaction between fruit colour, range size and diversification rate in palms by testing two hypotheses: (1) species with fruit colours attractive to birds have larger range sizes due to high dispersal ability and (2) disperser mobility affects whether small or large range size has higher diversification, and intermediate range size is expected to lead to the highest diversification rate regardless of disperser.Location Global.Time Period Contemporary (or present).Major Taxa Studied Palms (Arecaceae).Methods Palm species were grouped based on likely animal disperser group for given fruit colours. Range sizes were estimated by constructing alpha convex hull polygons from distribution data. We examined disperser group, range size or an interaction of both as possible drivers of change in diversification rate over time in a likelihood dynamic model (Several Examined State-dependent Speciation and Extinction [SecSSE]). Models were fitted, rate estimates were retrieved and likelihoods were compared to those of appropriate null models.Results Species with fruit colours associated with mammal dispersal had larger ranges than those with colours associated with bird dispersal. The best fitting SecSSE models indicated that the examined traits were not the primary driver of the heterogeneity in diversification rates in the model. Extinction rate complexity had a marked impact on model performance and on diversification rates.Main Conclusions Two traits related to dispersal mobility, range size and fruit colour, were not identified as the main drivers of diversification in palms. Increased model extinction rate complexity led to better performing models, which indicates that net diversification should be estimated rather than speciation alone. However, increased complexity may lead to incorrect SecSSE model conclusions without careful consideration. Finally, we find palms with more mobile dispersers do not have larger range sizes, meaning other factors are more important determinants of range size.
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| 8. |
- Pangala, Sunitha R., et al.
(författare)
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Large emissions from floodplain trees close the Amazon methane budget
- 2017
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Ingår i: Nature. - : NATURE PUBLISHING GROUP. - 0028-0836 .- 1476-4687. ; 552:7684, s. 230-
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Tidskriftsartikel (refereegranskat)abstract
- Wetlands are the largest global source of atmospheric methane (CH4)(1), a potent greenhouse gas. However, methane emission inventories from the Amazon floodplain(2,3), the largest natural geographic source of CH4 in the tropics, consistently underestimate the atmospheric burden of CH4 determined via remote sensing and inversion modelling(4,5), pointing to a major gap in our understanding of the contribution of these ecosystems to CH4 emissions. Here we report CH4 fluxes from the stems of 2,357 individual Amazonian floodplain trees from 13 locations across the central Amazon basin. We find that escape of soil gas through wetland trees is the dominant source of regional CH4 emissions. Methane fluxes from Amazon tree stems were up to 200 times larger than emissions reported for temperate wet forests(6) and tropical peat swamp forests(7), representing the largest non-ebullitive wetland fluxes observed. Emissions from trees had an average stable carbon isotope value (delta C-13) of -66.2 +/- 6.4 per mil, consistent with a soil biogenic origin. We estimate that floodplain trees emit 15.1 +/- 1.8 to 21.2 +/- 2.5 teragrams of CH4 a year, in addition to the 20.5 +/- 5.3 teragrams a year emitted regionally from other sources. Furthermore, we provide a topdown regional estimate of CH4 emissions of 42.7 +/- 5.6 teragrams of CH4 a year for the Amazon basin, based on regular vertical lower-troposphere CH4 profiles covering the period 2010-2013. We find close agreement between our top-down and combined bottom-up estimates, indicating that large CH4 emissions from trees adapted to permanent or seasonal inundation can account for the emission source that is required to close the Amazon CH4 budget. Our findings demonstrate the importance of tree stem surfaces in mediating approximately half of all wetland CH4 emissions in the Amazon floodplain, a region that represents up to one-third of the global wetland CH4 source when trees are combined with other emission sources.
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