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- Bergfur, Jenny, et al.
(författare)
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Effects of nutrient enrichment on C and N stable isotope ratios of invertebrates, fish and their food resources in boreal streams
- 2009
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Ingår i: Hydrobiologia. - : Springer. - 0018-8158 .- 1573-5117. ; 628, s. 67-79
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Tidskriftsartikel (refereegranskat)abstract
- Carbon and nitrogen stable isotopes are frequently used to study energy sources and food web structure in ecosystems, and more recently, to study the effects of anthropogenic stress on aquatic ecosystems. We investigated the effect of nutrient enrichment on d13C and d15N in fine (FPOM), coarse (CPOM) particulate organic matter, periphyton, invertebrates and fish in nine boreal streams in south-central Sweden. In addition, we analysed the diet of benthic consumers using stable isotope data. Increases in d15N of periphyton (R2 = 0.88), CPOM (0.78), invertebrates (0.92) and fish (0.89) were related to nutrient enrichment. In contrast, d13C signatures did not change along the nutrient gradient. Our results show that d15N has potential as a sensitive indicator of nutrient enrichment in boreal streams. Carbon and nitrogen isotopes failed to elucidate putative diets of selected aquatic consumers. Indeed, comparison of low- and high-impact sites showed that d13C of many consumers were found outside the ranges of basal resource d13C. Moreover, ranges of basal resource d13C and d15N overlapped at both low and high sites, making discrimination between the importance of allochthonous and autochthonous production difficult. Our findings show that a fractionation rate of 3.4% is not always be appropriate to assess trophic interactions, suggesting that more studies are needed on fractionation rates along gradients of impairment.
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| 4. |
- Luck, Gary W., et al.
(författare)
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Quantifying the Contribution of Organisms to the Provision of Ecosystem Services
- 2009
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Ingår i: BioScience. - : Oxford University Press (OUP). - 0006-3568 .- 1525-3244. ; 59:3, s. 223-235
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Tidskriftsartikel (refereegranskat)abstract
- Research on ecosystem services has grown rapidly over the last decade. Two conceptual frameworks have been published to guide ecological assessments of organisms that deliver services-the concepts of service-providing units (SPUs) and ecosystem service providers (ESPs). Here, we unite these frameworks and present an SPU-ESP continuum that offers a coherent conceptual approach for synthesizing the latest developments in ecosystem service research, and can direct future studies at all levels of organization. In particular, we show how the service-provider concept call be applied tit the population, functional group, and community levels, We strongly emphasize the need to identify and quantify the organisms and their characteristics (e.g., functional traits) that provide services, and to assess service provision relative to the demands of human beneficiaries. We use key examples from the literature to illustrate the new approach and to highlight gaps in knowledge, particularly in relation to the impact of species interactions and ecosystem dynamics on service provision.
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| 5. |
- Moss, Brian D., et al.
(författare)
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Climate change and the future of freshwater biodiversity in Europe : a primer for policy-makers
- 2009
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Ingår i: Freshwater Reviews. - : Freshwater Biological Association. - 1755-084X. ; 2:2, s. 103-130
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Tidskriftsartikel (refereegranskat)abstract
- Earth's climate is changing, and by the end of the 21st century in Europe, average temperatures are likely to have risen by at least 2 °C, and more likely 4 °C with associated effects on patterns of precipitation and the frequency of extreme weather events. Attention among policy-makers is divided about how to minimise the change, how to mitigate its effects, how to maintain the natural resources on which societies depend and how to adapt human societies to the changes. Natural systems are still seen, through a long tradition of conservation management that is largely species-based, as amenable to adaptive management, and biodiversity, mostly perceived as the richness of plant and vertebrate communities, often forms a focus for planning. We argue that prediction of particular species changes will be possible only in a minority of cases but that prediction of trends in general structure and operation of four generic freshwater ecosystems (erosive rivers, depositional floodplain rivers, shallow lakes and deep lakes) in three broad zones of Europe (Mediterranean, Central and Arctic-Boreal) is practicable. Maintenance and rehabilitation of ecological structures and operations will inevitably and incidentally embrace restoration of appropriate levels of species biodiversity. Using expert judgement, based on an extensive literature, we have outlined, primarily for lay policy makers, the pristine features of these systems, their states under current human impacts, how these states are likely to alter with a warming of 2 °C to 4 °C and what might be done to mitigate this. We have avoided technical terms in the interests of communication, and although we have included full referencing as in academic papers, we have eliminated degrees of detail that could confuse broad policy-making
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| 6. |
- Sandin, Leonard, et al.
(författare)
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Analys av befintlig övervakning med avseende på biologisk mångfald - Utredning
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I och med att det sextonde miljömålet (om biologisk mångfald) beslutats behöver vi få reda på hur väl dagens miljöövervakning av biologiska komponenter i sötvatten klarar av att utvärdera detta miljömål. Är dagens miljöövervakning av sötvatten upplagt på ett sådant sätt att mångfalden och förändringar i denna kan utvärderas och är de metoder vi använder i miljöövervakningen också lämpliga för att mäta och undersöka mångfalden.
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| 7. |
- Sandin, Leonard
(författare)
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Assessing impacts of hydromorphological degradation on macroinvertebrate indicators in rivers: examples, constraints and outlook
- 2009
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Ingår i: Integrated Environmental Assessment and Management. - 1551-3777 .- 1551-3793. ; 5, s. 86-96
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Tidskriftsartikel (refereegranskat)abstract
- An extensive amount of literature on linkages between the in-stream physical environment and river benthic macroinvertebrates reports a number of relationships across multiple spatial scales. We analyzed data on different spatial scales to elucidate the linkages between different measurements of hydromorphological degradation and commonly used macroinvertebrate indices. A regression analysis of 1049 sites from 3 countries revealed that the strongest relationship between a biotic metric—average score per taxon—and physiochemical variables (R2 = 0.61) was obtained with a multiple regression model that included concentration of total phosphorus and percent arable land in the catchment, as well as hydromorphological quality variables. Analyses of 3 data sets from streams primarily affected by hydromorphological degradation showed an overall weak relationship (max R2 = 0.25) with the River Habitat Survey data of 28 Swedish streams, whereas moderate (R2 ≈ 0.43) relationships with more detailed measurements of morphology were found in 2 Danish studies (39 and 6 streams, respectively). Although evidence exists in the literature on the importance of physical features for in-stream biota in general and macroinvertebrates specifically, we found only relatively weak relationships between various measures of hydromorphological stress and commonly used macroinvertebrate assessment tools. We attribute this to a combination of factors, including 1) the mixed nature of pressures acting on the majority of river reaches, 2) scaling issues (spatial and temporal) when relating habitat surveys to macroinvertebrate assessments, and 3) the scope of commonly used macroinvertebrate assessment systems (mainly focusing on water chemistry perturbation, such as eutrophication and acidification). The need is urgent to develop refined and updated biological assessment systems targeting hydromorphological stress for the use of the European Water Framework Directive (WFD) and national water-related policies.
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| 10. |
- Sandin, Leonard
(författare)
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The effects of catchment land-use, near-stream vegetation, and river hydromorphology on benthic macro invertebrate communities in a south-Swedish catchment
- 2009
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Ingår i: Fundamental and Applied Limnology. - : Schweizerbart. - 1863-9135. ; 174, s. 75-87
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Tidskriftsartikel (refereegranskat)abstract
- The Ema river catchment in South eastern Sweden has been inventoried for habitat quality (using the Swedish biotope inventory method) along large parts of its Course. Benthic macroinvertebrate samples have also been taken at 14 wadable stream sites within the catchment. Here, I quantified the relationship among catchment hand-Use, near-stream (surrounding area and riparian zone) vegetation, and in-stream hydromorphological variables and also between these variables and benthic macroinvertebrate community composition. Land-use near-stream wits the best predictor of variation in the in-stream hydromorphology (explaining 81.4% of the variation), whereas the catchment land-use explained 22.8% of the variation ill the near-stream zone and 36.7% of the variation in the in-stream hydromorphology. The benthic macroinvertebrate community composition wits most strongly related to the near-stream (Surrounding area and riparian zone) vegetation explaining 57.9% of the lotic macroinvertebrate variation, whereas catchment land-use explained 53.0% of the variation in the biota, and in-stream habitat features explained 40.0%. The scale at which a system is observed is important when determining which factor is/are influencing the Structure of the ecosystem. The near-stream characteristics were slightly more related in my study to the community composition of the biota than any of the habitat variables were related to (present day) land-use ill the catchment. These results imply that the use of a hierarchical organization to manage, assess and predict lotic biotic community process and patterns will enhance both understanding and scientific development in running waters.
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