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Benthic diatoms in lakes

environmental drivers and ecological assessment

Gottschalk, Steffi (2014). Benthic diatoms in lakes. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2014:47
ISBN 978-91-576-8042-6
eISBN 978-91-576-8043-3
[Doctoral thesis]

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In order to protect or improve surface waters ecosystem response to pressures needs to be quantified. Diatoms are frequently used for assessing ecological status in streams and for reconstructing water quality of lakes. However, ecological status assessment of European lakes based on extant diatom assemblages is rare.

The overall aim of this thesis is to facilitate the application of benthic diatoms in water quality assessment of boreal lakes, using methods developed for stream assessment. Therefore, I investigated (i) the main environmental drivers of lentic diatom assemblages, (ii) the structural differences between lentic and lotic diatom assemblages (iii) the implications of differences between lake and stream diatom assemblages for assessment, (iv) the power of different aquatic organisms as indicators of nutrient and acidity status in lakes, and (v) ecological thresholds of diatom and phytoplankton assemblage structure along a nutrient gradient in boreal lakes.

The major environmental drivers of benthic diatom assemblage composition in boreal lakes were gradients in acidity and nutrient status. In contrast, the distribution of ecological diatom guilds seems to be decoupled from nutrient availability in acidic compared to high pH aquatic systems. Diatom assemblage composition can thus be recommended for ecological status assessment of boreal lakes, whereas species-specific growth morphology and the drivers affecting growth morphology need further study. Most diatom taxa occurred in Swedish lakes and streams, but differences in frequency and abundance among lakes and streams were noted. However, the diatom indices IPS and ACID, developed for streams, responded similarly to nutrient and acidity gradients, respectively, in Swedish lakes and streams and can thus also be recommended for ecological status assessment of lakes. In nutrient poor boreal lakes, both primary producers and primary consumers were correlated with nutrient concentrations. Primary producers, especially diatoms, displayed a stronger response to pH than macro-invertebrates, possibly due to shorter generation times implying faster response. Nutrient thresholds in taxonomic and guild structure of benthic diatom assemblages in boreal lakes were found at low TP concentrations (18-26 μg L⁻¹). However, caution is advised in interpreting the response of some species to nutrients, as pH dependencies might obscure the response of some nutrient sensitive diatom species to TP.

Authors/Creators:Gottschalk, Steffi
Title:Benthic diatoms in lakes
Subtitle:environmental drivers and ecological assessment
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :2014
Number of Pages:52
I.Gottschalk, S., Kahlert, M. (2012). Shifts in taxonomical and guild composition of littoral diatom assemblages along environmental gradients. Hydrobiologia 694:41-56.
II.Kahlert, M. Gottschalk, S. (2014). Differences in benthic diatom assemblages between streams and lakes in Sweden and implications for ecological assessment. Freshwater Sciences DOI: 10.1086/675727
III.Gottschalk, S., Kahlert, M. Response of aquatic organisms to gradients of nutrients and acidity in boreal lakes. (manuscript).
IV.Gottschalk, S., Kahlert, M. Ecological thresholds of benthic diatoms and phytoplankton to nutrients in boreal lakes. (manuscript).
Place of Publication:Uppsala
Publisher:Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-576-8042-6
ISBN for electronic version:978-91-576-8043-3
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:M Aquatic sciences and fisheries > M40 Aquatic ecology
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Ecology
Agrovoc terms:phytoplankton, bacillariophyceae, lakes, rivers, invertebrates, indicator organisms, acidity, nutrient availability, eutrophication, benthic environment
Keywords:benthic diatoms, lakes, environmental drivers, streams, indicators, phytoplankton, littoral macroinvertebrates, efficacy, nutrient thresholds
Permanent URL:
ID Code:11193
Faculty:NJ - Fakulteten för naturresurser och jordbruksvetenskap
Department:(NL, NJ) > Dept. of Aquatic Sciences and Assessment
Deposited By: Steffi Gottschalk
Deposited On:20 May 2014 10:49
Metadata Last Modified:02 Dec 2014 11:06

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