| 41. |
- Angeler, David, et al.
(författare)
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FORUM: Effective management of ecological resilience – are we there yet?
- 2015
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Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 52, s. 1311-1315
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Tidskriftsartikel (refereegranskat)abstract
- Ecological resilience is developing into a credible paradigm for policy development and environmental management for preserving natural capital in a rapidly changing world. However, resilience emerges from complex interactions, limiting the translation of theory into practice. Main limitations include the following: (i) difficulty in quantification and detection of changes in ecological resilience, (ii) a lack of empirical evidence to support preventative orproactive management and (iii) difficulties in managing processes operating across socio-ecological systems that vary in space and time. We highlight recent research with the potential to address these limitations including new and/or improved indicators of resilience and tools to assess scale as a driver of resilience.Synthesis and applications. Effective resilience-based management must be adaptive in nature. To support this, we propose an operational model using resilience-based iterative management actions operating across scales.Effective resilience-based management must be adaptive in nature. To support this, we propose an operational model using resilience-based iterative management actions operating across scales.
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| 42. |
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| 43. |
- Angerbjörn, Anders, et al.
(författare)
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Carnivore conservation in practice : replicatedmanagement actions on a large spatial scale
- 2013
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Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 50:1, s. 59-67
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Tidskriftsartikel (refereegranskat)abstract
- More than a quarter of the world’s carnivores are threatened, often due to multiple andcomplex causes. Considerable research efforts are devoted to resolving the mechanisms behindthese threats in order to provide a basis for relevant conservation actions. However, evenwhen the underlying mechanisms are known, specific actions aimed at direct support for carnivoresare difficult to implement and evaluate at efficient spatial and temporal scales.2. We report on a 30-year inventory of the critically endangered Fennoscandian arctic foxVulpes lagopus L., including yearly surveys of 600 fox dens covering 21 000 km2. These surveysshowed that the population was close to extinction in 2000, with 40–60 adult animalsleft. However, the population subsequently showed a fourfold increase in size.3. During this time period, conservation actions through supplementary feeding and predatorremoval were implemented in several regions across Scandinavia, encompassing 79% of thearea. To evaluate these actions, we examined the effect of supplemental winter feeding andred fox control applied at different intensities in 10 regions. A path analysis indicated that47% of the explained variation in population productivity could be attributed to lemmingabundance, whereas winter feeding had a 29% effect and red fox control a 20% effect.4. This confirms that arctic foxes are highly dependent on lemming population fluctuationsbut also shows that red foxes severely impact the viability of arctic foxes. This study also highlightsthe importance of implementing conservation actions on extensive spatial and temporalscales, with geographically dispersed actions to scientifically evaluate the effects. We note thatpopulation recovery was only seen in regions with a high intensity of management actions.5. Synthesis and applications. The present study demonstrates that carnivore populationdeclines may be reversed through extensive actions that target specific threats. Fennoscandianarctic fox is still endangered, due to low population connectivity and expected climate impactson the distribution and dynamics of lemmings and red foxes. Climate warming is expected tocontribute to both more irregular lemming dynamics and red fox appearance in tundra areas;however, the effects of climate change can be mitigated through intensive managementactions such as supplemental feeding and red fox control.
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| 44. |
- Bejarano, Maria Dolores, et al.
(författare)
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Riparian plant guilds become simpler and most likely fewer following flow regulation
- 2018
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Ingår i: Journal of Applied Ecology. - : Wiley-Blackwell Publishing Inc.. - 0021-8901 .- 1365-2664. ; 55:1, s. 365-376
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Tidskriftsartikel (refereegranskat)abstract
- 1. River regulation affects riparian systems world-wide and conservation and restoration efforts are essential to retain biodiversity, and the functioning and services of riverine ecosystems. Effects of regulation on plant species richness have been widely addressed, but the filtering effect of regulation on guilds has received less attention.2. We used a functional trait approach to identify adaptive plant strategies through regulation-tolerant traits and predict shifts of riparian vegetation communities in response to regulation. We analysed variation in functional diversity across gradients of hydrological alteration in northern Sweden in relation to modified timing and infrequent major floods, along with frequent short-term inundation.3. Functional richness was similar in all study sites, but species richness declined with increasing intensity of regulation, and the species lost were largely functionally redundant (i.e. co-existing species that have similar contribution to an ecosystem function). Guilds of species intolerant to waterlogging were particularly unsuccessful in most regulated sites as they were affected by hydropower dams which replace major fluvial disturbances with frequent short inundation events. We predict that this guild will disappear, with likely consequences for the entire riverine ecosystem.4. Synthesis and applications. We conclude that functional traits tolerant to waterlogging or submergence and lack of major fluvial disturbances were key to understanding our results. We suggest that the functional trait approach can be integrated with knowledge of other ecosystem components to provide an understanding of ecosystem function that can be used to guide fluvial ecosystem management.
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| 45. |
- Bruno, Daniel, et al.
(författare)
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Impacts of environmental filters on functional redundancy in riparian vegetation
- 2016
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Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 53:3, s. 846-855
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Tidskriftsartikel (refereegranskat)abstract
- 1. Understanding and predicting ecosystem responses to multiple environmental pressures is a long-standing interest in ecology and environmental management. However, few studies have examined how the functional features of freshwater biological communities vary along multiple gradients of environmental stress. Furthermore, modelling these functional features for a whole river network constitutes a strong potential basis to improve ecosystem management. 2. We explored how functional redundancy of biological communities (FR, a functional feature related to the stability, resistance and resilience of ecosystems) responds to single and multiple environmental filters. We compared these responses with those of functional richness, evenness and divergence. We used riparian vegetation of a Mediterranean basin, and three of the main environmental filters affecting freshwater communities in such regions, that is drought, flow regulation and agricultural intensity, thus considering the potential effect of natural environmental variability. We also assessed the predictability of FR and estimated it for the entire river network. 3. We found that all functional measures decreased with increasing environmental filter intensity. However, FR was more sensitive to single and multiple environmental filters compared to other functional measures. The best-fitting model explained 59% of the FR variability and included agriculture, drought and flow regulation and the pairwise interactions of agriculture with drought and flow regulation. The parameters of the FR models differed from null model expectations reflecting a non-random decline along stress gradients. 4. Synthesis and applications. We found non-random detrimental effects along environmental filters' gradients for riparian functional redundancy (the most sensitive functional index), meaning that increased stress could jeopardize stability, resistance and resilience of these systems. In general, agriculture caused the greatest impact on functional redundancy and functional diversity measures, being the most important stressor for riparian functionality in the study area. Temporary streams flowing through an agricultural, regulated basin had reduced values of functional redundancy, whereas the free-flowing medium-sized, perennial water courses flowing through unaltered sub-basins displayed higher values of functional redundancy and potentially greater stability against human impacts. All these findings along with the predicted basin-wide variation of functional redundancy can assist environmental managers in improving monitoring and ecosystem management.
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| 46. |
- Certain, Grégoire
(författare)
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Spatio-temporal modelling of auk abundance after the Erika oil spill and implications for conservation
- 2016
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Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 53, s. 1862-1870
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Tidskriftsartikel (refereegranskat)abstract
- Species distribution models are widely used in applied ecology and conservation. While accounting for spatial dependences is now the rule, temporal dependences have rarely been dealt with explicitly. In this study, we analyse wintering auk distribution in the Bay of Biscay and English Channel and estimate changes in abundance within and between years while accounting for space-time dependencies. We then propose a retrospective estimate of the impact of the Erika oil spill that occurred in December 1999. Two series of extensive aerial surveys, repeated at intervals of 1-2 months, were carried out at a 10-year interval off the French Atlantic coast (2001-2002 and 2011-2012). Spatially and temporally explicit Bayesian models were fitted to these data to provide spatio-temporal predictions of auk abundance. These were then used to compare abundances within the area affected by the Erika oil spill two and twelve years after the catastrophe. The results showed that 155 million auks wintered in the study area in 2011-2012. The main wintering area was the English Channel (more than one million auks) but the Bay of Biscay also became an important area in the middle of winter (470000 auks) owing to a strong southward shift in auk distribution. Two years after the catastrophe (2001-2002), the area affected by the Erika oil spill hosted a small proportion of auks of the Bay of Biscay - about 80000 individuals. This number increased by more than three times 10 years later and reached 270000 individuals, whereas no significant change was detected elsewhere. We suggest that it could result from a recovery after the extra-mortality induced by the Erika oil spill.Policy implications. This study identified major auk wintering areas, with abundances much higher than previously realized. Oil spills have occurred regularly in these areas, with major delayed impacts on auk breeding populations. The worst case scenario would be if a major oil spill occurred in the English Channel in February, when abundance reaches one million auks. Although such a disaster has not so far occurred, stricter policies on the transport of hydrocarbons should be implemented to prevent such a possibility.This study identified major auk wintering areas, with abundances much higher than previously realized. Oil spills have occurred regularly in these areas, with major delayed impacts on auk breeding populations. The worst case scenario would be if a major oil spill occurred in the English Channel in February, when abundance reaches one million auks. Although such a disaster has not so far occurred, stricter policies on the transport of hydrocarbons should be implemented to prevent such a possibility.
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| 47. |
- Ecke, Frauke
(författare)
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Contrasting the roles of section length and instream habitat enhancement for river restoration success: a field study of 20 European restoration projects
- 2015
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Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 52, s. 1518-1527
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Tidskriftsartikel (refereegranskat)abstract
- Restoration of river hydromorphology often has limited detected effects on river biota. One frequently discussed reason is that the restored river length is insufficient to allow populations to develop and give the room for geomorphological processes to occur. We investigated ten pairs of restored river sections of which one was a large project involving a long, intensively restored river section and one represented a smaller restoration effort. The restoration effect was quantified by comparing each restored river section to an upstream non-restored section. We sampled the following response variables: habitat composition in the river and its floodplain, three aquatic organism groups (aquatic macrophytes, benthic invertebrates and fish), two floodplain-inhabiting organism groups (floodplain vegetation, ground beetles), as well as food web composition and land-water interactions reflected by stable isotopes. For each response variable, we compared the difference in dissimilarity of the restored and nearby non-restored section between the larger and the smaller restoration projects. In a second step, we regrouped the pairs and compared restored sections with large changes in substrate composition to those with small changes. When comparing all restored to all non-restored sections, ground beetles were most strongly responding to restoration, followed by fish, floodplain vegetation, benthic invertebrates and aquatic macrophytes. Aquatic habitats and stable isotope signatures responded less strongly. When grouping the restored sections by project size, there was no difference in the response to restoration between the projects targeting long and short river sections with regard to any of the measured response variables except nitrogen isotopic composition. In contrast, when grouping the restored sections by substrate composition, the responses of fish, benthic invertebrates, aquatic macrophytes, floodplain vegetation and nitrogen isotopic composition were greater in sections with larger changes in substrate composition as compared to those with smaller changes.Synthesis and applications. The effects of hydromorphological restoration measures on aquatic and floodplain biota strongly depend on the creation of habitat for aquatic organisms, which were limited or not present prior to restoration. These positive effects on habitats are not necessarily related to the restored river length. Therefore, we recommend a focus on habitat enhancement in river restoration projects.The effects of hydromorphological restoration measures on aquatic and floodplain biota strongly depend on the creation of habitat for aquatic organisms, which were limited or not present prior to restoration. These positive effects on habitats are not necessarily related to the restored river length. Therefore, we recommend a focus on habitat enhancement in river restoration projects.
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| 48. |
- Edsman, Lennart, et al.
(författare)
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Detection of crayfish plague spores in large freshwater systems
- 2014
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Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 51, s. 544-553
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Tidskriftsartikel (refereegranskat)abstract
- Our study demonstrates a low amount of pathogen spores are present in aquatic environments with non-indigenous crayfish species, emphasizing the need for large-volume filtering techniques for successful detection. The approach can be used for risk assessments and to improve conservation and management strategies of crayfish in Europe. Applications of this method include targeted disease surveillance, habitat evaluation prior to crayfish re-stockings and water monitoring that can minimize disease transmission and spread, for example in crayfish farms and prior to fish movements for stocking purposes.
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| 49. |
- Feckler, Alexander, et al.
(författare)
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Cryptic species diversity: an overlooked factor in environmental management?
- 2014
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Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 51, s. 958-967
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Tidskriftsartikel (refereegranskat)abstract
- 1. Molecular genetic methods continuously uncover cryptic lineages harboured by various species. However, from an applied perspective, it remains unclear whether and to which extent such a genetic diversity affects biological traits (e. g. ecological, behavioural and physiological characteristics) and environmental management.2. We assessed potential deviations regarding the trait 'environmental stress tolerance' using individuals from five field populations of each of two cryptic lineages (called A and B) comprised under the nominal species Gammarus fossarum. We used ammonia as a chemical stressor while assessing the feeding rate on leaf discs as a measure of sublethal response. In this context, we established a restriction fragment length polymorphism assay to allow a rapid identification of the lineages.3. We observed a biologically meaningful and statistically significant twofold higher overall tolerance of one cryptic lineage, lineage B, over the other. Confounding factors that may have the potential to influence the test results, such as life stage, sex, season of collection, parasitism, physiological status of organisms and upstream land-use patterns of the river catchments, were either controlled for or displayed only minor deviations between lineages.4. Synthesis and applications. The trait differences observed in the present study seem to be mainly explained by the considerable genetic differentiation between cryptic lineages of one nominal species. Although traits other than tolerance have been minimally investigated in this context, this study indicates implications in the reliability and quality of environmental monitoring and management if cryptic lineage complexes are ignored.
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| 50. |
- Feckler, Alexander, et al.
(författare)
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Inorganic fungicides as routinely applied in organic and conventional agriculture can increase palatability but reduce microbial decomposition of leaf litter
- 2015
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Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 52, s. 310-322
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Tidskriftsartikel (refereegranskat)abstract
- 1. The application of fungicides is considered an indispensable measure to secure crop production. These substances, however, may unintentionally enter surface waters via run-off, potentially affecting the microbial community. To assess such risks adequately, authorities recently called for suitable test designs involving relevant aquatic micro-organisms.2. We assessed the structural and functional responses of leaf-associated microbial communities, which play a key role in the breakdown of allochthonous leaf material in streams, towards the inorganic fungicides copper (Cu) and elemental sulphur (S). These substances are of particular interest as they are authorized for both conventional and organic farming in many countries of the world. We used the food choice of the amphipod shredder Gammarus fossarum (indicative for micro-organism-mediated leaf palatability) as well as microbial leaf decomposition as functional endpoints. Moreover, the leaf-associated microbial communities were characterized by means of bacterial density, fungal biomass and community composition facilitating mechanistic understanding of the observed functional effects.3. While Gammarus preferred Cu-exposed leaves over unexposed ones, microbial leaf decomposition was reduced by both Cu and S (up to 30%). Furthermore, Cu exposure decreased bacterial densities (up to 60%), stimulated the growth of leaf-associated fungi (up to 100%) and altered fungal community composition, while S did not affect any of the assessed structural endpoints.4. Synthesis and applications. We observed both structural and functional changes in leafassociated microbial communities at inorganic fungicide concentrations realistic for surface water bodies influenced by conventional and organic farming. Our data hence justify a careful re-evaluation of the environmental safety of the agricultural use of these compounds. Moreover, inclusion of an experimental design similar to the one used in this study in lower tier environmental risk assessments of antimicrobial compounds may aid to safeguard the integrity of aquatic microbial communities and the functions they provide.
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