Absorption characteristics, major elements and chl a content of samples from Pond 19 at Zackenberg, NE Greenland, supplement to: Cazzanelli, Matteo; Forsström, Laura; Rautio, Milla; Michelsen, Anders; Christoffersen, Kirsten Seestern (2012): Benthic resources are the key to Daphnia middendorffiana survival in a high arctic pond. Freshwater Biology, 57(3), 541-551
1. Shallow arctic lakes and ponds have simple and short food webs, but large uncertainties remain about benthic-pelagic links in these systems. We tested whether organic matter of benthic origin supports zooplankton biomass in a pond in NE Greenland, using stable isotope analysis of carbon and nitro...
| Main Authors: | , , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
PANGAEA - Data Publisher for Earth & Environmental Science
2012
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.1594/pangaea.808244 https://doi.pangaea.de/10.1594/PANGAEA.808244 |
| Summary: | 1. Shallow arctic lakes and ponds have simple and short food webs, but large uncertainties remain about benthic-pelagic links in these systems. We tested whether organic matter of benthic origin supports zooplankton biomass in a pond in NE Greenland, using stable isotope analysis of carbon and nitrogen in the pond itself and in a 13C-enrichment enclosure experiment. In the latter, we manipulated the carbon isotope signature of benthic algae to enhance its isotopic discrimination from other potential food sources for zooplankton.2. The cladoceran Daphnia middendorffiana responded to the 13C-enrichment of benthic mats with progressively increasing d13C values, suggesting benthic feeding. Stable isotope analysis also pointed towards a negligible contribution of terrestrial carbon to the diet of D. middendorffiana. This agreed with the apparent dominance of autochthonous dissolved organic matter in the pond revealed by analysis of coloured dissolved organic matter.3. Daily net production by phytoplankton in the pond (18 mg C/m**2/day) could satisfy only up to half of the calculated minimum energy requirements of D. middendorffiana (35 mg C/m**2/day), whereas benthic primary production alone (145 mg C/m**2/day) was more than sufficient.4. Our findings highlight benthic primary production as a major dietary source for D. middendorffiana in this system and suggest that benthic organic matter may play a key role in sustaining pelagic secondary production in such nutrient-limited high arctic ponds. : Data extracted in the frame of a joint ICSTI/PANGAEA IPY effort, see http://doi.pangaea.de/10.1594/PANGAEA.150150 |
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