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Ecological integrity of boreal streams

assessing impacts on community structure and function

Bergfur, Jenny (2007). Ecological integrity of boreal streams. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2007:50
ISBN 978-91-576-7349-7
[Doctoral thesis]

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Running waters provide a number of services for humans, such as drinking water and food resources and many freshwater animals are confined and specialised to this environment. However, this natural resource has become increasingly impacted by humans resulting in a substantial loss of biodiversity and services. To assess ecological integrity of streams a number of bioassessment schemes have been developed and most of these are based on community structure and composition. Although many of the biological metrics developed have been used successfully in bioassessment, it has been suggested that ecosystem functions, such as leaf-litter decomposition, should be incorporated in modern bioassessment schemes. In this thesis I compare a number of structural metrics with functional metrics along a nutrient gradient in nine boreal streams in south-central Sweden to assess the potential of ecosystem function as a biomonitoring tool. Leaf-litter breakdown (Alnus glutinosa (L.) Gaertner) was studied during four seasons and stable isotope (δ13C and δ15N) and stoichiometric ratios (C:N) of phytobenthos, CPOM, FPOM, invertebrates and fish were also analysed. My results indicate that leaf-litter breakdown is a relatively insensitive tool to assess ecosystem impairment compared to invertebrate metrics. However, δ15N in organic matter has been suggested as a potential tool to assess ecological integrity of streams and my results support this conjecture. A strong response in δ15N in organic matter with nutrient enrichment was revealed, suggesting that δ15N could serve as a simple tool to assess nutrient enrichment effects in boreal streams. I also found that leaf-litter associated fungi and invertebrates were positively correlated with leaf-litter breakdown rates and a nutrient gradient. Moreover, I found that certain dominating species, e.g. waterlouse (Asellus aquaticus (L.)), can have a strong influence on ecosystem processes. In this thesis I show that leaf-litter breakdown is not a simple low-cost biomonitoring tool as several field trips were necessary to assure adequate litter-bag recovery. Also natural factors, such as fluctuating water levels and heavy snow fall, resulted in substantial loss of litter bags thereby confounding data interpretation.

Authors/Creators:Bergfur, Jenny
Title:Ecological integrity of boreal streams
Subtitle:assessing impacts on community structure and function
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :2007
Number of Pages:39
ALLI. Sandin, L. & Bergfur, J. Biodiversity of boreal stream organisms along a nutrient gradient: identification of possible biodiversity indicator surrogates (Manuscript) II. Bergfur, J., Johnson, R. K., Sandin, L. & Goedkoop, W. Assessing the ecological integrity of boreal streams: a comparison of functional and structural responses. Fundamental and Applied Limnology (Archiv für Hydrobiologie) 168 (2), 113-125. III. Bergfur, J. Seasonal variation in leaf-litter breakdown in nine boreal streams: implications for assessing functional integrity. (Submitted manuscript). IV. Bergfur, J., Johnson, R. K., Sandin, L., Goedkoop, W. & Nygren, K. Effects of nutrient enrichment on boreal streams: invertebrates, fungi and leaf-litter breakdown. Freshwater Biology (Accepted 2007). V. Bergfur, J., Johnson, R. K., Sandin, L. and Goedkoop, W. Effects of nutrient enrichment on δ13C, δ15N and C:N ratios in boreal streams. (Submitted manuscript).
Place of Publication:Uppsala
ISBN for printed version:978-91-576-7349-7
Publication Type:Doctoral thesis
Full Text Status:Public
Agrovoc terms:rivers, environmental impact assessment, biodiversity, monitoring, alnus glutinosa, forest litter, biodegradation, eutrophication, asellus, isotopes, freshwater ecology, environmental impact, sweden
Keywords:bioassessment, nutrient enrichment, biodiversity, leaf-litter breakdown, stable isotope ecology, ecological stoichiometry
Permanent URL:
ID Code:1406
Department:(NL, NJ) > Dept. of Environmental Assessment (until 080831)
Deposited By: Jenny Bergfur
Deposited On:23 Apr 2007 00:00
Metadata Last Modified:02 Dec 2014 10:11

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