| 1. |
- Ibanez, Thomas, et al.
(författare)
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Damage to tropical forests caused by cyclones is driven by wind speed but mediated by topographical exposure and tree characteristics
- 2024
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Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 30:5
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Tidskriftsartikel (refereegranskat)abstract
- Each year, an average of 45 tropical cyclones affect coastal areas and potentially impact forests. The proportion of the most intense cyclones has increased over the past four decades and is predicted to continue to do so. Yet, it remains uncertain how topographical exposure and tree characteristics can mediate the damage caused by increasing wind speed. Here, we compiled empirical data on the damage caused by 11 cyclones occurring over the past 40 years, from 74 forest plots representing tropical regions worldwide, encompassing field data for 22,176 trees and 815 species. We reconstructed the wind structure of those tropical cyclones to estimate the maximum sustained wind speed (MSW) and wind direction at the studied plots. Then, we used a causal inference framework combined with Bayesian generalised linear mixed models to understand and quantify the causal effects of MSW, topographical exposure to wind (EXP), tree size (DBH) and species wood density (ρ) on the proportion of damaged trees at the community level, and on the probability of snapping or uprooting at the tree level. The probability of snapping or uprooting at the tree level and, hence, the proportion of damaged trees at the community level, increased with increasing MSW, and with increasing EXP accentuating the damaging effects of cyclones, in particular at higher wind speeds. Higher ρ decreased the probability of snapping and to a lesser extent of uprooting. Larger trees tended to have lower probabilities of snapping but increased probabilities of uprooting. Importantly, the effect of ρ decreasing the probabilities of snapping was more marked for smaller than larger trees and was further accentuated at higher MSW. Our work emphasises how local topography, tree size and species wood density together mediate cyclone damage to tropical forests, facilitating better predictions of the impacts of such disturbances in an increasingly windier world.
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| 2. |
- Muscarella, Robert, et al.
(författare)
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The global abundance of tree palms
- 2020
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 29:9, s. 1495-1514
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Tidskriftsartikel (refereegranskat)abstract
- AimPalms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change.LocationTropical and subtropical moist forests.Time periodCurrent.Major taxa studiedPalms (Arecaceae).MethodsWe assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ≥10 cm diameter at breast height) abundance relative to co‐occurring non‐palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure.ResultsOn average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long‐term climate stability. Life‐form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non‐tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above‐ground biomass, but the magnitude and direction of the effect require additional work.ConclusionsTree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests.
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| 3. |
- Olsson, Lennart, et al.
(författare)
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The State of the World’s Arable Land
- 2023
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Ingår i: Annual Review of Environment and Resources. - 1543-5938. ; 48, s. 451-475
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Forskningsöversikt (refereegranskat)abstract
- For millennia, agriculture has been shaping landscapes on Earth. Technological change has increased agricultural productivity dramatically, especially in the past six decades, but also resulted in trade-offs such as land and soil degradation, emission of greenhouse gases (GHGs), and spreading of toxic substances. In this article we review the impacts of agriculture on the world’s arable land. We start by synthesizing information on the extent of arable land and associated agricultural practices, followed by a review of the state of the art of soil health and soil carbon. We review processes of land degradation, emission of GHGs, and threats to biodiversity. To conclude, we review key social and economic aspects of arable land and identify some important concerns for the future. The article ends on a positive note describing a potential new pathway for agriculture—to gradually adopt polycultures of novel perennial grain crops.
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| 4. |
- Peterson, A. Townsend, et al.
(författare)
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ENM2020 : A free online course and set of resources on modeling species niches and distributions
- 2022
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Ingår i: Biodiversity Informatics. - : The University of Kansas. - 1546-9735. ; 17, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- The field of distributional ecology has seen considerable recent attention, particularly surrounding the theory, protocols, and tools for Ecological Niche Modeling (ENM) or Species Distribution Modeling (SDM). Such analyses have grown steadily over the past two decades-including a maturation of relevant theory and key concepts-but methodological consensus has yet to be reached. In response, and following an online course taught in Spanish in 2018, we designed a comprehensive English-language course covering much of the underlying theory and methods currently applied in this broad field. Here, we summarize that course, ENM2020, and provide links by which resources produced for it can be accessed into the future. ENM2020 lasted 43 weeks, with presentations from 52 instructors, who engaged with >2500 participants globally through >14,000 hours of viewing and >90,000 views of instructional video and question-and-answer sessions. Each major topic was introduced by an "Overview" talk, followed by more detailed lectures on subtopics. The hierarchical and modular format of the course permits updates, corrections, or alternative viewpoints, and generally facilitates revision and reuse, including the use of only the Overview lectures for introductory courses. All course materials are free and openly accessible (CC-BY license) to ensure these resources remain available to all interested in distributional ecology.
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| 5. |
- Swanson, Heather Anne, et al.
(författare)
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History as grounds for interdisciplinarity : promoting sustainable woodlands via an integrative ecological and socio-cultural perspective
- 2021
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Ingår i: One Earth. - : Elsevier. - 2590-3330 .- 2590-3322. ; 4:2, s. 226-237
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Tidskriftsartikel (refereegranskat)abstract
- While calls for interdisciplinary research in environmental contexts are common, it often remains a struggle to integrate humanities/qualitative social sciences insights with those of bio-physical approaches. We propose that cross-disciplinary historical perspectives can open new avenues for collaboration among social and natural scientists while expanding visions of possible future environments and management scenarios. We make these arguments through attention to woodlands, which are under pressure from complex socio-ecological stressors that can best be understood from interdisciplinary perspectives. By combining deep ecological and shallower social historical approaches, we show how history can both enrich our understandings of woodland pasts and provide a ground for better combining the case-based insights of humanistic history with those of deep-time ecological history. We conclude that such interdisciplinary historical approaches are important not only for research, but also for management (especially rewilding and scenario-building), as the surprisingly large range of past changes reminds us that future conditions can be more varied than typically acknowledged.
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