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Limiting factors of periphytic algae in Arctic streams
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
2017 (English)Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesisAlternative title
Begränsande faktorer för påväxtalger i arktiska bäckar (Swedish)
Abstract [en]

Algae are the most common primary producers in stream ecosystems, contributing as much as 80 % of the total primary production. The production of these ecosystems is strongly influenced by the terrestrial habitats, which are in turn likely to be altered by climate change.

In arctic ecosystems, where the effects of climate may be most pronounced, there are important unknowns about how abiotic factors such as light, temperature, nutrients, flow regimes interact to influence stream productivity. This study therefore aimed to understand what controls the rate of benthic algal growth in Arctic streams by measuring the accumulation of algal biomass on artificial surfaces across arctic stream types in Norrbotten, Sweden. Ceramic tiles were placed at 36 locations distributed across tundra and birch forest streams. Algal accumulation on tiles was then measured over 7 weeks using a fluorometer (Bentothorch) together with a number of likely controlling factors (light, temperature, dissolved nutrients and depth). I observed a significant difference in algal accumulation between the stream types (p<0.05), with nearly three times greater biomass in birch forest compared to tundra streams. However, these differences were not related to variation in light and water temperature. Dissolved nitrogen had a significant correlation with algal accumulation although with a lot of unexplained variation. Unmeasured hydrological aspects such as stream flow may have had large significance for differences in algal growth between the higher-gradient tundra and lower-gradient birch forest streams.  Overall, I hypothesize that the productivity of these systems is limited by nitrogen or several parameters working together and/or that these systems are affected by an unmeasured parameter (e.g., grazing, hydrological disturbance). While my results did not clearly establish the factors regulating algal growth in these streams it suggests that dissolved nitrogen is an important factor. The observed differences between stream types suggest that the productivity of arctic streams and the potential effect of climate change may be affected by small-scale variation in geomorphology and hydrology.  

Place, publisher, year, edition, pages
2017. , 15 p.
National Category
Natural Sciences Biological Sciences
Identifiers
URN: urn:nbn:se:umu:diva-133300OAI: oai:DiVA.org:umu-133300DiVA: diva2:1086640
Educational program
Bachelor of Science in Biology and Earthscience
Supervisors
Examiners
Available from: 2017-04-03 Created: 2017-04-03 Last updated: 2017-04-04Bibliographically approved

Open Access in DiVA

fulltext(739 kB)49 downloads
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File name FULLTEXT01.pdfFile size 739 kBChecksum SHA-512
8481c82ded550af510568bbe3eb4585664be7685f1987fc49c5224d6fd3af319d1db0fa2113e13584bced618fe52050af7b82a8db48a7ecc3a905298a077f2a8
Type fulltextMimetype application/pdf

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Department of Ecology and Environmental Sciences
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CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf