| 1. |
- Ralimanana, H., et al.
(författare)
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Madagascar’s extraordinary biodiversity: Threats and opportunities
- 2022
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 378:6623
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Forskningsöversikt (refereegranskat)abstract
- Madagascar’s unique biota is heavily affected by human activity and is under intense threat. Here, we review the current state of knowledge on the conservation status of Madagascar’s terrestrial and freshwater biodiversity by presenting data and analyses on documented and predicted species-level conservation statuses, the most prevalent and relevant threats, ex situ collections and programs, and the coverage and comprehensiveness of protected areas. The existing terrestrial protected area network in Madagascar covers 10.4% of its land area and includes at least part of the range of the majority of described native species of vertebrates with known distributions (97.1% of freshwater fishes, amphibians, reptiles, birds, and mammals combined) and plants (67.7%). The overall figures are higher for threatened species (97.7% of threatened vertebrates and 79.6% of threatened plants occurring within at least one protected area). International Union for Conservation of Nature (IUCN) Red List assessments and Bayesian neural network analyses for plants identify overexploitation of biological resources and unsustainable agriculture as the most prominent threats to biodiversity. We highlight five opportunities for action at multiple levels to ensure that conservation and ecological restoration objectives, programs, and activities take account of complex underlying and interacting factors and produce tangible benefits for the biodiversity and people of Madagascar.
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| 2. |
- Antonelli, Alexandre, 1978, et al.
(författare)
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Madagascar's extraordinary biodiversity : Evolution, distribution, and use
- 2022
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 378:6623, s. 962-
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Tidskriftsartikel (refereegranskat)abstract
- Madagascar's biota is hyperdiverse and includes exceptional levels of endemicity. We review the current state of knowledge on Madagascar's past and current terrestrial and freshwater biodiversity by compiling and presenting comprehensive data on species diversity, endemism, and rates of species description and human uses, in addition to presenting an updated and simplified map of vegetation types. We report a substantial increase of records and species new to science in recent years; however, the diversity and evolution of many groups remain practically unknown (e.g., fungi and most invertebrates). Digitization efforts are increasing the resolution of species richness patterns and we highlight the crucial role of field- and collections-based research for advancing biodiversity knowledge and identifying gaps in our understanding, particularly as species richness corresponds closely to collection effort. Phylogenetic diversity patterns mirror that of species richness and endemism in most of the analyzed groups. We highlight humid forests as centers of diversity and endemism because of their role as refugia and centers of recent and rapid radiations. However, the distinct endemism of other areas, such as the grassland-woodland mosaic of the Central Highlands and the spiny forest of the southwest, is also biologically important despite lower species richness. The documented uses of Malagasy biodiversity are manifold, with much potential for the uncovering of new useful traits for food, medicine, and climate mitigation. The data presented here showcase Madagascar as a unique " living laboratory" for our understanding of evolution and the complex interactions between people and nature. The gathering and analysis of biodiversity data must continue and accelerate if we are to fully understand and safeguard this unique subset of Earth's biodiversity.
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| 3. |
- Cooke, Robert S., 1992, et al.
(författare)
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Anthropogenic disruptions to longstanding patterns of trophic-size structure in vertebrates
- 2022
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Ingår i: Nature Ecology & Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 6:6, s. 684-92
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Tidskriftsartikel (refereegranskat)abstract
- Diet and body mass are inextricably linked in vertebrates: while herbivores and carnivores have converged on much larger sizes, invertivores and omnivores are, on average, much smaller, leading to a roughly U-shaped relationship between body size and trophic guild. Although this U-shaped trophic-size structure is well documented in extant terrestrial mammals, whether this pattern manifests across diverse vertebrate clades and biomes is unknown. Moreover, emergence of the U-shape over geological time and future persistence are unknown. Here we compiled a comprehensive dataset of diet and body size spanning several vertebrate classes and show that the U-shaped pattern is taxonomically and biogeographically universal in modern vertebrate groups, except for marine mammals and seabirds. We further found that, for terrestrial mammals, this U-shape emerged by the Palaeocene and has thus persisted for at least 66 million years. Yet disruption of this fundamental trophic-size structure in mammals appears likely in the next century, based on projected extinctions. Actions to prevent declines in the largest animals will sustain the functioning of Earth's wild ecosystems and biomass energy distributions that have persisted through deep time. Analysis of diet and body size in terrestrial and aquatic vertebrates shows that a U-shaped relationship between body size and trophic guild prevails across extant vertebrates with the exception of marine mammals and seabirds. Analysis of fossil data shows that, for terrestrial mammals, this pattern has persisted for at least 66 million years, despite anthropogenic perturbance, which may have greater effects in the next centuries.
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| 4. |
- Cooke, Rob, et al.
(författare)
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Undiscovered bird extinctions obscure the true magnitude of human-driven extinction waves
- 2023
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Birds are among the best-studied animal groups, but their prehistoric diversity is poorly known due to low fossilization potential. Hence, while many human-driven bird extinctions (i.e., extinctions caused directly by human activities such as hunting, as well as indirectly through human-associated impacts such as land use change, fire, and the introduction of invasive species) have been recorded, the true number is likely much larger. Here, by combining recorded extinctions with model estimates based on the completeness of the fossil record, we suggest that at least ~1300–1500 bird species (~12% of the total) have gone extinct since the Late Pleistocene, with 55% of these extinctions undiscovered (not yet discovered or left no trace). We estimate that the Pacific accounts for 61% of total bird extinctions. Bird extinction rate varied through time with an intense episode ~1300 CE, which likely represents the largest human-driven vertebrate extinction wave ever, and a rate 80 (60–95) times the background extinction rate. Thus, humans have already driven more than one in nine bird species to extinction, with likely severe, and potentially irreversible, ecological and evolutionary consequences.
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| 5. |
- Andermann, Tobias, et al.
(författare)
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iucn_sim: a new program to simulate future extinctions based on IUCN threat status
- 2021
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Ingår i: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 44:2, s. 162-176
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Tidskriftsartikel (refereegranskat)abstract
- The ongoing environmental crisis poses an urgent need to forecast the who, where and when of future species extinctions, as such information is crucial for targeting conservation efforts. Commonly, such forecasts are made based on conservation status assessments produced by the International Union for Conservation of Nature (IUCN). However, when researchers apply these IUCN conservation status data for predicting future extinctions, important information is often omitted, which can impact the accuracy of these predictions. Here we present a new approach and a software for simulating future extinctions based on IUCN conservation status information, which incorporates generation length information of individual species when modeling extinction risks. Additionally, we explicitly model future changes in conservation status for each species, based on status transition rates that we estimate from the IUCN assessment history of the last decades. Finally, we apply a Markov chain Monte Carlo algorithm to estimate extinction rates for each species, based on the simulated future extinctions. These estimates inherently incorporate the chances of conservation status changes and the generation length for each given species and are specific to the simulated time frame. We demonstrate the utility of our approach by estimating future extinction rates for all bird species. Our average extinction rate estimate for the next 100 yr across all birds is 6.98 x 10(-4) extinctions per species-year, and we predict an expected biodiversity loss of between 669 and 738 bird species within that time frame. Further, the rate estimates between species sharing the same IUCN status show larger variation than the rates estimated with alternative approaches, which reflects expected differences in extinction risk among taxa of the same conservation status. Our method demonstrates the utility of applying species-specific information to the estimation of extinction rates, rather than assuming equal extinction risks for species assigned to the same conservation status.
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| 6. |
- Cooke, Robert S., 1992, et al.
(författare)
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Ecological distinctiveness of birds and mammals at the global scale
- 2020
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Ingår i: Global Ecology and Conservation. - : Elsevier BV. - 2351-9894. ; 22
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Tidskriftsartikel (refereegranskat)abstract
- Ecologically distinct species - species with distinct trait combinations - are not directly prioritized in current conservation frameworks. The consequence of this blind spot means species with the most distinct ecological strategies might be lost. Here, we quantify ecological distinctiveness, based on six traits, for 10,960 bird and 5,278 mammal species, summarizing species-level ecological irreplaceability. We find that threatened birds and mammals are, on average, more ecologically distinct. Specific examples of ecologically distinct and highly threatened species are Great Indian Bustard, Amsterdam Albatross, Asian Elephant and Sumatran Rhinoceros. These species have potentially irreplaceable ecological roles and their loss could undermine the integrity of ecological processes and functions. Yet, we also identify ecologically distinct widespread generalists, such as Lesser Black-backed Gull and Wild Boar. These generalist species have distinct ecological strategies that allow them to thrive across multiple environments. Thus, we suggest that high ecological distinctiveness is associated with either high extinction risk or successful hyper-generalism. We also find that ecologically distinct species are generally charismatic (using a previous measure of public perceptions of charisma). We thus highlight a conservation opportunity: capitalizing on public preferences for charismatic species could provide support for the conservation of the most ecologically distinct birds and mammals. Overall, our prioritization framework supports the conservation of species with irreplaceable ecological strategies, complementing existing frameworks that target extinction risk and evolutionary distinctiveness. © 2020 The Authors
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| 7. |
- Richards, C., et al.
(författare)
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Biological traits of seabirds predict extinction risk and vulnerability to anthropogenic threats
- 2021
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 30:5, s. 973-986
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Tidskriftsartikel (refereegranskat)abstract
- Aim Seabirds are heavily threatened by anthropogenic activities, and their conservation status is deteriorating rapidly. Nonetheless, these pressures are unlikely to impact all species uniformly. It remains an open question whether seabirds with similar ecological roles are responding similarly to human pressures. Our aims were as follows: (a) to test whether threatened versus non-threatened seabirds are separated in trait space; (b) to quantify the similarity of species' roles (redundancy) per IUCN Red List Category; and (c) to identify traits that render species vulnerable to anthropogenic threats. Location Global. Time period Contemporary. Major taxa studied Seabirds. Methods We compile and impute eight traits that relate to species' vulnerabilities and ecosystem functioning across 341 seabird species. Using these traits, we build a mixed-data principal component analysis of species' trait space. We quantify trait redundancy using the unique trait combinations (UTCs) approach. Finally, we undertake a similarity of percentages analysis to identify which traits explain the greatest difference between threat groups. Results We find that seabirds segregate in trait space based on IUCN threat status, indicating that anthropogenic impacts are selectively removing large, long-lived, pelagic surface feeders with narrow habitat breadths. We also find that threatened species have higher trait redundancy, whereas non-threatened species have relatively limited redundancy. Finally, we find that species with narrow habitat breadths, fast reproductive speeds and varied diets are more likely to be threatened by habitat-modifying processes (e.g., pollution and natural system modifications), whereas pelagic specialists with slow reproductive speeds and varied diets are vulnerable to threats that directly impact survival and fecundity (e.g., invasive species and biological resource use) and climate change. Species with no threats are non-pelagic specialists with invertebrate diets and fast reproductive speeds. Main conclusions Our results suggest that both threatened and non-threatened species contribute unique ecological strategies. Consequently, conserving both threat groups, but importantly with contrasting approaches, might avoid potential changes in ecosystem functioning and stability.
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| 8. |
- Sayol, Ferran, et al.
(författare)
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Loss of functional diversity through anthropogenic extinctions of island birds is not offset by biotic invasions
- 2021
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 7:46
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Tidskriftsartikel (refereegranskat)abstract
- Human impacts reshape ecological communities through the extinction and introduction of species. The combined impact of these factors depends on whether non-native species fill the functional roles of extinct species, thus buffering the loss of functional diversity. This question has been difficult to address, because comprehensive information about past extinctions and their traits is generally lacking. We combine detailed information about extinct, extant, and established alien birds to quantify historical changes in functional diversity across nine oceanic archipelagos. We found that alien species often equal or exceed the number of anthropogenic extinctions yet apparently perform a narrower set of functional roles as current island assemblages have undergone a substantial and ubiquitous net loss in functional diversity and increased functional similarity among assemblages. Our results reveal that the introduction of alien species has not prevented anthropogenic extinctions from reducing and homogenizing the functional diversity of native bird assemblages on oceanic archipelagos.
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| 9. |
- Spake, R., et al.
(författare)
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Regional variability in landscape effects on forest bird communities
- 2020
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Ingår i: Landscape Ecology. - : Springer Science and Business Media LLC. - 0921-2973 .- 1572-9761. ; 35, s. 1055-1071
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Tidskriftsartikel (refereegranskat)abstract
- Context Functional responses to landscape heterogeneity are context-dependent, hampering the transferability of landscape-scale conservation initiatives. Japan provides a unique opportunity to test for regional modification of landscape effects due to its broad temperature gradient, coincident with a gradient of historical disturbance intensity. Objectives To quantify and understand how regional contexts modify forest bird community responses to landscape heterogeneity across Japan. Methods We characterised the functional trait composition and diversity of breeding bird communities from 297 forest sites, and applied a cross-scale analytical framework to explain regional variation in community responses. Results The effects of landscape diversity, coincident with forest loss, varied in strength and even direction across the temperature gradient. Cool regions of Japan with highly forested, homogeneous landscapes supported bird communities dominated by forest specialists: those with narrow habitat breadths and insectivorous diets. Warmer regions comprised communities dominated by generalists with wider habitat breadths, even in contiguous, highly forested landscapes. Heterogeneous landscapes selected for generalists, and only promoted functional trait diversity in cool regions where both specialists and generalists can be supplied by a diverse regional pool. Conclusions Our results provide evidence that regional variation in trait responses to landscape heterogeneity-driven by past environmental filtering and broad-scale climates-leads to differential community responses across Japan. Future research that seeks a nuanced understanding of the regional modification of landscape variables will better serve to inform and target real-world conservation efforts.
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