| Category |
Text Publication |
| Reference Category |
Journals |
| DOI |
10.1111/fwb.12979
|
| Document |
Shareable Link |
| Title (Primary) |
Benthic carbon is inefficiently transferred in the food webs of two eutrophic shallow lakes |
| Author |
Lischke, B.; Mehner, T.; Hilt, S.; Attermeyer, K.; Brauns, M.; Brothers, S.; Grossart, H.-P.; Köhler, J.; Scharnweber, K.; Gaedke, U. |
| Source Titel |
Freshwater Biology |
| Year |
2017 |
| Department |
FLOEK |
| Volume |
62 |
| Issue |
10 |
| Page From |
1693 |
| Page To |
1706 |
| Language |
englisch |
| Supplements |
https://onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1111%2Ffwb.12979&attachmentId=183518364
https://onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1111%2Ffwb.12979&attachmentId=183518365 |
| Keywords |
bacterial production; benthic food chain; pelagic food chain; quantitative food webs; trophic transfer efficiency |
| UFZ wide themes |
RU2; |
| Abstract |
- The
sum of benthic autotrophic and bacterial production often exceeds the
sum of pelagic autotrophic and bacterial production, and hence may
contribute substantially to whole-lake carbon fluxes, especially in
shallow lakes. Furthermore, both benthic and pelagic autotrophic and
bacterial production are highly edible and of sufficient nutritional
quality for animal consumers. We thus hypothesised that pelagic and
benthic transfer efficiencies (ratios of production at adjacent trophic
levels) in shallow lakes should be similar.
- We performed whole
ecosystem studies in two shallow lakes (3.5 ha, mean depth 2 m), one
with and one without submerged macrophytes, and quantified pelagic and
benthic biomass, production and transfer efficiencies for bacteria,
phytoplankton, epipelon, epiphyton, macrophytes, zooplankton,
macrozoobenthos and fish. We expected higher transfer efficiencies in
the lake with macrophytes, because these provide shelter and food for
macrozoobenthos and may thus enable a more efficient conversion of basal
production to consumer production.
- In both lakes, the majority
of the whole-lake autotrophic and bacterial production was provided by
benthic organisms, but whole-lake primary consumer production mostly
relied on pelagic autotrophic and bacterial production. Consequently,
transfer efficiency of benthic autotrophic and bacterial production to
macrozoobenthos production was an order of magnitude lower than the
transfer efficiency of pelagic autotrophic and bacterial production to
rotifer and crustacean production. Between-lake differences in transfer
efficiencies were minor.
- We discuss several aspects potentially
causing the unexpectedly low benthic transfer efficiencies, such as the
food quality of producers, pelagic–benthic links, oxygen concentrations
in the deeper lake areas and additional unaccounted consumer production
by pelagic and benthic protozoa and meiobenthos at intermediate or top
trophic levels. None of these processes convincingly explain the large
differences between benthic and pelagic transfer efficiencies.
- Our
data indicate that shallow eutrophic lakes, even with a major share of
autotrophic and bacterial production in the benthic zone, can function
as pelagic systems with respect to primary consumer production. We
suggest that the benthic autotrophic production was mostly transferred
to benthic bacterial production, which remained in the sediments,
potentially cycling internally in a similar way to what has previously
been described for the microbial loop in pelagic habitats. Understanding
the energetics of whole-lake food webs, including the fate of the
substantial benthic bacterial production, which is either mineralised at
the sediment surface or permanently buried, has important implications
for regional and global carbon cycling.
|
| Persistent UFZ Identifier |
https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=19113 |
Lischke, B., Mehner, T., Hilt, S., Attermeyer, K., Brauns, M., Brothers, S., Grossart, H.-P., Köhler, J., Scharnweber, K., Gaedke, U. (2017):
Benthic carbon is inefficiently transferred in the food webs of two eutrophic shallow lakes
Freshw. Biol. 62 (10), 1693 - 1706 10.1111/fwb.12979 |
