0000000000172421

AUTHOR

Maarten Van Hardenbroek

Supplementary methods and results from Trophic state changes can affect the importance of methane-derived carbon in aquatic food webs

Additional details on methods and results (as referred to in the main article) and a semi-colon delimited table with downcore isotope and TP records

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Abundance and δ13C values of fatty acids in lacustrine surface sediments: Relationships with in-lake methane concentrations

Proxy-indicators in lake sediments provide the only approach by which the dynamics of in-lake methane cycling can be examined on multi-decadal to centennial time scales. This information is necessary to constrain how lacustrine methane production, oxidation and emissions are expected to respond to global change drivers. Several of the available proxies for reconstructing methane cycle changes of lakes rely on interpreting past changes in the abundance or relevance of methane oxidizing bacteria (MOB), either directly (e.g. via analysis of bacterial lipids) or indirectly (e.g. via reconstructions of the past relevance of MOB in invertebrate diet). However, only limited information is availabl…

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Land Use Affects Carbon Sources to the Pelagic Food Web in a Small Boreal Lake

Small humic forest lakes often have high contributions of methane-derived carbon in their food webs but little is known about the temporal stability of this carbon pathway and how it responds to environmental changes on longer time scales. We reconstructed past variations in the contribution of methanogenic carbon in the pelagic food web of a small boreal lake in Finland by analyzing the stable carbon isotopic composition (δ13C values) of chitinous fossils of planktivorous invertebrates in sediments from the lake. The δ13C values of zooplankton remains show several marked shifts (approx. 10 ‰), consistent with changes in the proportional contribution of carbon from methane-oxidizing bacteri…

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Flotsam samples can help explain the δ13C and δ15N values of invertebrate resting stages in lake sediment

The stable isotopic composition of chitinous remains of Cladocera (water fleas) and freshwater Bryozoa (moss animals) preserved in lake sediment records can provide supporting insights into past environmental and ecosystem changes in lakes. Here we explore whether analyses of these remains isolated from lake flotsam can provide information on the driving variables affecting the isotopic composition of these remains. We collected flotsam in 53 lakes and found enough material in 33 lakes to measure the stable carbon and nitrogen isotope ratios (expressed as δ13C and δ15N values, respectively) of resting stages. These values were compared with lake characteristics, water chemistry measurements…

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Flotsam samples can help explain the δ13C and δ15N values of invertebrate resting stages in lake sediment

Abstract The stable isotopic composition of chitinous remains of Cladocera (water fleas) and freshwater Bryozoa (moss animals) preserved in lake sediment records can provide supporting insights into past environmental and ecosystem changes in lakes. Here we explore whether analyses of these remains isolated from lake flotsam can provide information on the driving variables affecting the isotopic composition of these remains. We collected flotsam in 53 lakes and found enough material in 33 lakes to measure the stable carbon and nitrogen isotope ratios (expressed as δ13C and δ15N values, respectively) of resting stages. These values were compared with lake characteristics, water chemistry mea…

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Trophic state changes can affect the importance of methane-derived carbon in aquatic food webs

Methane-derived carbon, incorporated by methane-oxidizing bacteria, has been identified as a significant source of carbon in food webs of many lakes. By measuring the stable carbon isotopic composition (δ13C values) of particulate organic matter, Chironomidae andDaphniaspp. and their resting eggs (ephippia), we show that methane-derived carbon presently plays a relevant role in the food web of hypertrophic Lake De Waay, The Netherlands. Sediment geochemistry, diatom analyses and δ13C measurements of chironomid andDaphniaremains in the lake sediments indicate that oligotrophication and re-eutrophication of the lake during the twentieth century had a strong impact on in-lake oxygen availabili…

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Data for: Flotsam samples can help explain the δ13C and δ15N values of invertebrate resting stages in lake sediment records

This supplementary table provides the data used in the manuscript. It gives an overview of the 53 lakes that were sampled for flotsam and (where available) their water chemistry, morphological characteristics, and stable isotope values of resting stages and sedimentary organic matter

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Data for: The stable isotope composition of organic and inorganic fossils in lake sediment records: current understanding, challenges, and future directions

Table 1 and Supplementary Table belonging to "The stable isotope composition of organic and inorganic fossils in lake sediment records: current understanding, challenges, and future directions". THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOVE

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