| 1. |
- Auffret, Alistair G., et al.
(författare)
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HistMapR : Rapid digitization of historical land-use maps in R
- 2017
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Ingår i: Methods in Ecology and Evolution. - 2041-210X. ; 8:11, s. 1453-1457
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Tidskriftsartikel (refereegranskat)abstract
- Habitat destruction and degradation represent serious threats to biodiversity, and quantification of land-use change over time is important for understanding the consequences of these changes to organisms and ecosystem service provision. Comparing land use between maps from different time periods allows estimation of the magnitude of habitat change in an area. However, digitizing historical maps manually is time-consuming and analyses of change are usually carried out at small spatial extents or at low resolutions. HistMapR contains a number of functions that can be used to semi-automatically digitize historical land use according to a map's colours, as defined by the RGB bands of the raster image. We test the method on different historical land-use map series and compare results to manual digitizations. Digitization is fast, and agreement with manually digitized maps of around 80-90% meets common targets for image classification. We hope that the ability to quickly classify large areas of historical land use will promote the inclusion of land-use change into analyses of biodiversity, species distributions and ecosystem services.
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| 2. |
- Auffret, Alistair G., et al.
(författare)
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Plant functional connectivity - integrating landscape structure and effective dispersal
- 2017
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Ingår i: Journal of Ecology. - : Wiley. - 0022-0477 .- 1365-2745. ; 105:6, s. 1648-1656
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Forskningsöversikt (refereegranskat)abstract
- 1. Dispersal is essential for species to survive the threats of habitat destruction and climate change. Combining descriptions of dispersal ability with those of landscape structure, the concept of functional connectivity has been popular for understanding and predicting species' spatial responses to environmental change. 2. Following recent advances, the functional connectivity concept is now able to move beyond landscape structure to consider more explicitly how other external factors such as climate and resources affect species movement. We argue that these factors, in addition to a consideration of the complete dispersal process, are critical for an accurate understanding of functional connectivity for plant species in response to environmental change. 3. We use recent advances in dispersal, landscape and molecular ecology to describe how a range of external factors can influence effective dispersal in plant species, and how the resulting functional connectivity can be assessed. 4. Synthesis. We define plant functional connectivity as the effective dispersal of propagules or pollen among habitat patches in a landscape. Plant functional connectivity is determined by a combination of landscape structure, interactions between plant, environment and dispersal vectors, and the successful establishment of individuals. We hope that this consolidation of recent research will help focus future connectivity research and conservation.
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| 3. |
- Hooftman, Danny A. P., et al.
(författare)
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Could green infrastructure supplement ecosystem service provision from semi-natural grasslands?
- 2023
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Ingår i: Journal of Environmental Management. - Stockholm : Elsevier BV. - 0301-4797 .- 1095-8630. ; 328
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Tidskriftsartikel (refereegranskat)abstract
- Ancient semi-natural grasslands in Europe are important for ecosystem service (ES) provision. Often, the surrounding matrix contains ‘Grassland Green Infrastructure’ (GGI) that contain grassland species which have the potential to supplement grassland ES provision across the landscape. Here we investigate the potential for GGI to deliver a set of complementary ES, driven by plant composition.We surveyed 36 landscapes across three European countries comprising core grasslands and their surrounding GGI. We calculated community-level values of plant species characteristics to provide indicators for four ES: nature conservation value, pollination, carbon storage and aesthetic appeal.Inferred ES delivery for GGI was substantially lower than in core grasslands for conservation, pollination and aesthetic appeal indicators, but not for carbon storage. These differences were driven by the GGI having 17% fewer plant species, and compositional differences, with 61% of species unique to the core grasslands. In addition, connectivity to the core, the amount of GGI and inferred seed dispersal distances by livestock, were strongly positively correlated with conservation value, pollination and aesthetic indicators. All ES indicators showed similar responses to the GGI spatial structure and distance to the core, suggesting robust effects of these drivers on ES. We projected that improved landscape-wide delivery of nature conservation value and pollination could be achieved through targeted GGI management. Reductions in the distances seeds would need to disperse, more GGI, along with a diversification of the GGI elements, were predicted to enhance service credits.We conclude that for vegetation-related ES, species surveys can be employed to assess potential ES delivery. Creating and enhancing GGI is a useful landscape management strategy to supplement the ES delivered by ancient grasslands.
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| 4. |
- Hooftman, Danny A. P., et al.
(författare)
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Introgression potential of downy mildew resistance from lettuce to Lactuca serriola and its relevance for plant fitness
- 2007
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Ingår i: Basic and Applied Ecology. - : Elsevier BV. - 1439-1791 .- 1618-0089. ; 8:2, s. 135-146
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Tidskriftsartikel (refereegranskat)abstract
- Hybridization between plant species may cause ecological changes in species, enhancing their potential to become invasive. Increasing evidence suggests that the expanding distribution of Lactuca serriola could (partly) be caused by hybridization with its closest relative, the crop plant L. sativa (lettuce). Fitness advantages in hybrids may result from heterosis and epistasis but single added traits may enhance hybrid fitness as well. Here, we study the potential for introgression of an important crop trait, downy mildew (Bremia lactucae) resistance, into L. serriola hybrids. We monitored the abundance of B. lactucae on wild L. serriola in The Netherlands to test its impact potential. We found that B. lactucae is common in The Netherlands: B. lactucae occurred in 33 of the 35 surveyed populations of L. serriola. Subsequently, under regulated conditions, using two physiotypes of B. lactucae (BL-16 and BL-18), we recorded (i) quantitative conidiophore and (ii) haustoria development in seedlings. Furthermore, we explored its effects on plant fitness. Based on the (non-) occurrence of conidiophores, genomic segments from L. sativa that include Bremia resistance are present and expressing in these hybrids for at least two hybrid generations. However, haustoria density was lower in all hybrids, irrespective of physiotype or siring cultivar. We attributed this to heterosis. Furthermore, all plants shed infected leaves, but we observed no effects of infection on reproductive fitness. We therefore suggest that when L. serriola gains resistance to B. lactucae, the fitness effects are tow. The hypothesis that the gain of B. lactucae resistance is causally related to the recent spread of L. serriola has become less Likely. If hybridization is connected to this at all, it seems through heterosis. We conclude that it is important to study fitness impacts of introgressed traits along with other ecological factors. (c) 2006 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.
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| 5. |
- Hooftman, Danny, et al.
(författare)
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Dispersal limitation, eutrophication and propagule pressure constrain the conservation value of Grassland Green Infrastructure
- 2021
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Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 258
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Tidskriftsartikel (refereegranskat)abstract
- Semi-natural grasslands harbour many of Europe's species of conservation interest. Although larger grasslands are the focus of most conservation activity, many grassland fragments are scattered across landscapes –in small patches or along linear elements– which can form Grassland Green Infrastructure (GGI). GGI has the potential to enhance landscape diversity by creating functioning metacommunities comprising of large semi-natural grasslands and these surrounding fragments. While often highlighted in conservation policy, little is known about the biodiversity supported by green infrastructure itself and thus its conservation potential.To address this issue, we contrasted plant communities in 36 ‘core’ grassland sites across three European countries with communities in the surrounding GGI. We related compositional differences to amount and type of GGI habitat (patches or linear), and the distances for seed dispersal by livestock from core sites. We found substantial differences between the GGI and the core sites, with a mean 54% species turn-over. These differences indicated filtering of stress tolerant species characteristic of low nutrient conditions, and semi-natural grassland specialists. Species with poorer dispersal abilities declined strongly with increasing distances from the core sites. The many additional species in the GGI, not found in the core sites, were predominantly those with a competitive strategy and high seed dispersal ability.We conclude that the biodiversity-supporting role of GGI across Europe is severely constrained by eutrophication, dispersal limitation and external propagule pressure. Actions to improve the quality of GGI might include enhancing dispersal by livestock combined with more type-diversification and less intensively used grassland habitats.
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| 6. |
- Jorgensen, Rikke Bagger, et al.
(författare)
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The variability of processes involved in transgene dispersal-case studies from Brassica and related genera
- 2009
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 1614-7499 .- 0944-1344. ; 16:4, s. 389-395
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Forskningsöversikt (refereegranskat)abstract
- Background, aim, and scope We strive to predict consequences of genetically modified plants (GMPs) being cultivated openly in the environment, as human and animal health, biodiversity, agricultural practise and farmers' economy could be affected. Therefore, it is unfortunate that the risk assessment of GMPs is burdened by uncertainty. One of the reasons for the uncertainty is that the GMPs are interacting with the ecosystems at the release site thereby creating variability. This variability, e. g. in gene flow, makes consequence analysis difficult. The review illustrates the great uncertainty of results from gene-flow analysis. Main features Many independent experiments were performed on the individual processes in gene flow. The results comprise information both from laboratory, growth chambers and field trials, and they were generated using molecular or phenotypic markers and analysis of fitness parameters. Monitoring of the extent of spontaneous introgression in natural populations was also performed. Modelling was used as an additional tool to identify key parameters in gene flow. Results The GM plant may affect the environment directly or indirectly by dispersal of the transgene. Magnitude of the transgene dispersal will depend on the GM crop, the agricultural practise and the environment of the release site. From case-to-case these three factors provide a variability that is reflected in widely different likelihoods of transgene dispersal and fitness of introgressed plants. In the present review, this is illustrated through a bunch of examples mostly from our own research on oilseed rape, Brassica napus. In the Brassica cases, the variability affected all five main steps in the process of gene dispersal. The modelling performed suggests that in Brassica, differences in fitness among plant genome classes could be a dominant factor in the establishment and survival of introgressed populations. Discussion Up to now, experimental analyses have mainly focused on studying the many individual processes of gene flow. This can be criticised, as these experiments are normally carried out in widely different environments and with different genotypes, and thus providing bits and pieces difficult to assemble. Only few gene-flow studies have been performed in natural populations and over several plant generations, though this could give a more coherent and holistic view. Conclusion The variability inherent in the processes of gene flow in Brassica is apparent and remedies are wished for. One possibility is to expose the study species to additional experiments and monitoring, but this is costly and will likely not cover all possible scenarios. Another remedy is modelling gene flow. Modelling is a valuable tool in identifying key factors in the gene-flow process for which more knowledge is needed, and identifying parameters and processes which are relatively insensitive to change and therefore require less attention in future collections of data. But the interdependence between models and experimental data is extensive, as models depend on experimental data for their development or testing. Recommendations More and more transgenic varieties are being grown worldwide harbouring genes that might potentially affect the environment ( e. g. drought tolerance, salt tolerance, disease tolerance, pharmaceutical genes). This calls for a thorough risk assessment. However, in Brassica, the limited and uncertain knowledge on gene flow is an obstacle to this. Modelling of gene flow should be optimised, and modelling outputs verified in targeted field studies and at the landscape level. Last but not least, it is important to remember that transgene flow in itself is not necessarily a thread, but it is the consequences of gene flow that may jeopardise the ecosystems and the agricultural production. This emphasises the importance of consequence analysis of genetically modified plants.
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| 7. |
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| 8. |
- Plue, Jan, et al.
(författare)
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Functional rather than structural connectivity explains grassland plant diversity patterns following landscape scale habitat loss
- 2020
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Ingår i: Landscape Ecology. - 0921-2973 .- 1572-9761.
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Tidskriftsartikel (refereegranskat)abstract
- Context Functional connectivity is vital for plant species dispersal, but little is known about how habitat loss and the presence of green infrastructure interact to affect both functional and structural connectivity, and the impacts of each on species groups. Objectives We investigate how changes in the spatial configuration of species-rich grasslands and related green infrastructure such as road verges, hedgerows and forest borders in three European countries have influenced landscape connectivity, and the effects on grassland plant biodiversity. Methods We mapped past and present land use for 36 landscapes in Belgium, Germany and Sweden, to estimate connectivity based on simple habitat spatial configuration (structural connectivity) and accounting for effective dispersal and establishment (functional connectivity) around focal grasslands. We used the resulting measures of landscape change to interpret patterns in plant communities. Results Increased presence of landscape connecting elements could not compensate for large scale losses of grassland area resulting in substantial declines in structural and functional connectivity. Generalist species were negatively affected by connectivity, and responded most strongly to structural connectivity, while functional connectivity determined the occurrence of grassland specialists in focal grasslands. Restored patches had more generalist species, and a lower density of grassland specialist species than ancient patches. Conclusions Protecting both species rich grasslands and dispersal pathways within landscapes is essential for maintaining grassland biodiversity. Our results show that increases in green infrastructure have not been sufficient to offset loss of semi-natural habitat, and that landscape links must be functionally effective in order to contribute to grassland diversity.
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| 9. |
- Plue, Jan, et al.
(författare)
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Green infrastructure can promote plant functional connectivity in a grassland species around fragmented semi-natural grasslands in NW-Europe
- 2022
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Ingår i: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 2022:10
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Tidskriftsartikel (refereegranskat)abstract
- Species may benefit from green infrastructure, i.e. the network of natural and anthropogenic habitat remnants in human-dominated landscapes, if it helps isolated populations in remaining habitat patches to be functionally connected. The importance of green infrastructure is therefore increasingly emphasized in conservation policy to counter biodiversity loss. However, there is limited evidence, particularly in plants, that green infrastructure promotes functional connectivity, i.e. supports the colonization of habitat patches across a landscape. We applied landscape genetics to test whether the green infrastructure supports structural and functional connectivity in the grassland perennial Galium verum, in 35 landscapes in Belgium, Germany and Sweden. We used multivariate genetic clustering techniques, nestedness analyses and conditional inference trees to examine landscape-scale patterns in genetic diversity and structure of plant populations in the green infrastructure surrounding semi-natural grasslands. Inferred functional connectivity explained genetic variation better than structural connectivity, yielding positive effects on genetic variation. The road verge network, a major structural component of the green infrastructure and its functional connectivity, most effectively explained genetic diversity and composition in G. verum. Galium verum ramets occupying the surrounding landscape proved to be genetic subsets of focal grassland populations, shaping a nested landscape population genetic structure with focal grasslands, particularly ancient ones, harbouring unique genetic diversity. This nested pattern weakened as road network density increased, suggesting road verge networks enable high landscape occupancy by increased habitat availability and facilitates gene flow into the surrounding landscape. Our study proposes that green infrastructure can promote functional connectivity, providing that a plant species can survive outside of core habitat patches. As this often excludes habitat specialist species, conservation practice and policy should primarily focus on ancient, managed semi-natural grasslands. These grasslands both harbour unique genetic diversity and act as primary gene and propagule sources for the surrounding landscape, highlighting their conservation value.
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| 10. |
- Traveset, Anna, et al.
(författare)
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Effect of green infrastructure on restoration of pollination networks and plant performance in semi-natural dry grasslands across Europe
- 2024
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Ingår i: Journal of Applied Ecology. - 0021-8901 .- 1365-2664.
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Tidskriftsartikel (refereegranskat)abstract
- Agricultural intensification, afforestation and land abandonment are major drivers of biodiversity loss in semi-natural grasslands across Europe. Reversing these losses requires the reinstatement of plant–animal interactions such as pollination. Here we assessed the differences in species composition and patterns of plant-pollinator interactions in ancient and restored grasslands and how these patterns are influenced by landscape connectivity, across three European regions (Belgium, Germany and Sweden).We evaluated the differences in pollinator community assemblage, abundance and interaction network structure between 24 ancient and restored grasslands. We then assessed the effect of surrounding landscape functional connectivity (i.e. green infrastructure, GI) on these variables and tested possible consequences on the reproduction of two model plants, Lotus corniculatus and Salvia pratensis.Neither pollinator richness nor species composition differed between ancient and restored grasslands. A high turnover of interactions across grasslands was detected but was mainly due to replacement of pollinator and plant species. The impact of grassland restoration was consistent across various pollinator functional groups, whereas the surrounding GI had differential effects. Notably, bees, butterflies, beetles, and dipterans (excluding hoverflies) exhibited the most significant responses to GI variations. Interestingly, networks in restored grasslands were more specialised (i.e. less functionally redundant) than in ancient ones and also showed a higher number of insect visits to habitat-generalist plant species. Landscape connectivity had a similar effect, with habitat-specialist plant species receiving fewer visits at higher GI values.Fruit set in S. pratensis and L. corniculatus was unaffected by grassland type or GI. However, the fruit set in the specialist S. pratensis increased with the number of pollinator visits, indicating a positive correlation between pollinator activity and reproductive success in this particular species.Synthesis and applications. Our findings provide evidence of the necessity to enhance ecosystem functions while avoiding biotic homogenisation. Restoration programs should aim at increasing landscape connectivity which influences plant communities, pollinator assemblages and their interaction patterns. To avoid generalist species taking over from specialists in restored grasslands, we suggest reinforcing the presence of specialist species in the latter, for instance by means of introductions, as well as increasing the connectivity to source populations.
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| 11. |
- Willcock, Simon, et al.
(författare)
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A Continental-Scale Validation of Ecosystem Service Models
- 2019
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Ingår i: Ecosystems. - : Springer Science and Business Media LLC. - 1432-9840 .- 1435-0629. ; 22:8, s. 1902-1917
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Tidskriftsartikel (refereegranskat)abstract
- Faced with environmental degradation, governments worldwide are developing policies to safeguard ecosystem services (ES). Many ES models exist to support these policies, but they are generally poorly validated, especially at large scales, which undermines their credibility. To address this gap, we describe a study of multiple models of five ES, which we validate at an unprecedented scale against 1675 data points across sub-Saharan Africa. We find that potential ES (biophysical supply of carbon and water) are reasonably well predicted by the existing models. These potential ES models can also be used as inputs to new models for realised ES (use of charcoal, firewood, grazing resources and water), by adding information on human population density. We find that increasing model complexity can improve estimates of both potential and realised ES, suggesting that developing more detailed models of ES will be beneficial. Furthermore, in 85% of cases, human population density alone was as good or a better predictor of realised ES than ES models, suggesting that it is demand, rather than supply that is predominantly determining current patterns of ES use. Our study demonstrates the feasibility of ES model validation, even in data-deficient locations such as sub-Saharan Africa. Our work also shows the clear need for more work on the demand side of ES models, and the importance of model validation in providing a stronger base to support policies which seek to achieve sustainable development in support of human well-being.
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| 12. |
- Willcock, Simon, et al.
(författare)
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Do ecosystem service maps and models meet stakeholders' needs? A preliminary survey across sub-Saharan Africa
- 2016
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Ingår i: Ecosystem Services. - : Elsevier BV. - 2212-0416 .- 2212-0416. ; 18, s. 110-117
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Tidskriftsartikel (refereegranskat)abstract
- To achieve sustainability goals, it is important to incorporate ecosystem service (ES) information into decision-making processes. However, little is known about the correspondence between the needs of ES information users and the data provided by the researcher community. We surveyed stakeholders within sub-Saharan Africa, determining their ES data requirements using a targeted sampling strategy. Of those respondents utilising ES information (> 90%; n = 60), 27% report having sufficient data; with the remainder requiring additional data - particularly at higher spatial resolutions and at multiple points in time. The majority of respondents focus on provisioning and regulating services, particularly food and fresh water supply (both 58%) and climate regulation (49%). Their focus is generally at national scales or below and in accordance with data availability. Among the stakeholders surveyed, we performed a follow-up assessment for a sub-sample of 17 technical experts. The technical experts are unanimous that ES models must be able to incorporate scenarios, and most agree that ES models should be at least 90% accurate. However, relatively coarse-resolution (1-10 km(2)) models are sufficient for many services. To maximise the impact of future research, dynamic, multi-scale datasets on ES must be delivered alongside capacity-building efforts.
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| 13. |
- Willcock, Simon, et al.
(författare)
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Ensembles of ecosystem service models can improve accuracy and indicate uncertainty
- 2020
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 747
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Tidskriftsartikel (refereegranskat)abstract
- Many ecosystem services (ES) models exist to support sustainable development decisions. However, most ES studies use only a single modelling framework and, because of a lack of validation data, rarely assess model accuracy for the study area. In line with other research themes which have high model uncertainty, such as climate change, ensembles of ES models may better serve decision-makers by providing more robust and accurate estimates, as well as provide indications of uncertainty when validation data are not available. To illustrate the benefits of an ensemble approach, we highlight the variation between alternative models, demonstrating that there are large geographic regions where decisions based on individual models are not robust. We test if ensembles are more accurate by comparing the ensemble accuracy of multiple models for six ES against validation data across sub-Saharan Africa with the accuracy of individual models. We find that ensembles are better predictors of ES, being 5.0-6.1% more accurate than individual models. We also find that the uncertainty (i.e. variation among constituent models) of the model ensemble is negatively correlated with accuracy and so can be used as a proxy for accuracy when validation is not possible (e.g. in data-deficient areas or when developing scenarios). Since ensembles are more robust, accurate and convey uncertainty, we recommend that ensemble modelling should be more widely implemented within ES science to better support policy choices and implementation.
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| 14. |
- Willcock, Simon, et al.
(författare)
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Model ensembles of ecosystem services fill global certainty and capacity gaps
- 2023
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Ingår i: Science Advances. - 2375-2548. ; 9:14
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Tidskriftsartikel (refereegranskat)abstract
- Sustaining ecosystem services (ES) critical to human well-being is hindered by many practitioners lacking access to ES models (“the capacity gap”) or knowledge of the accuracy of available models (“the certainty gap”), especially in the world’s poorer regions. We developed ensembles of multiple models at an unprecedented global scale for five ES of high policy relevance. Ensembles were 2 to 14% more accurate than individual models. Ensemble accuracy was not correlated with proxies for research capacity, indicating that accuracy is distributed equitably across the globe and that countries less able to research ES suffer no accuracy penalty. By making these ES ensembles and associated accuracy estimates freely available, we provide globally consistent ES information that can support policy and decision-making in regions with low data availability or low capacity for implementing complex ES models. Thus, we hope to reduce the capacity and certainty gaps impeding local-to global-scale movement toward ES sustainability.
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