Algal species composition and phosphorus recycling at contrasting grazing pressure: an experimental study in sub‐Antarctic lakes with two trophic levels
1. To test the response of algal communities to altered grazer abundance in lakes lacking efficient predators on herbivores, we performed field and experimental studies in two sub‐Antarctic lakes (South Georgia). 2. The number of algal species in these high latitude lakes is low, and all dominant sp...
Published in: | Freshwater Biology |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
1997
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1046/j.1365-2427.1997.d01-531.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2427.1997.d01-531.x https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2427.1997.d01-531.x |
id |
crwiley:10.1046/j.1365-2427.1997.d01-531.x |
---|---|
record_format |
openpolar |
spelling |
crwiley:10.1046/j.1365-2427.1997.d01-531.x 2024-06-02T07:56:19+00:00 Algal species composition and phosphorus recycling at contrasting grazing pressure: an experimental study in sub‐Antarctic lakes with two trophic levels HANSSON, LARS‐ANDERS TRANVIK, LARS 1997 http://dx.doi.org/10.1046/j.1365-2427.1997.d01-531.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2427.1997.d01-531.x https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2427.1997.d01-531.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Freshwater Biology volume 37, issue 1, page 45-53 ISSN 0046-5070 1365-2427 journal-article 1997 crwiley https://doi.org/10.1046/j.1365-2427.1997.d01-531.x 2024-05-03T11:16:52Z 1. To test the response of algal communities to altered grazer abundance in lakes lacking efficient predators on herbivores, we performed field and experimental studies in two sub‐Antarctic lakes (South Georgia). 2. The number of algal species in these high latitude lakes is low, and all dominant species have grazer‐resistant adaptations, including spines in three dimensions ( Staurastrum sp.), large size ( Tribonema sp.), a mucus sheet allowing viable passage through the gut ( Chlamydocapsa sp., Elakatothrix sp.) or ability to recruit individuals from the sediment surface ( Mallomonas sp.). 3. Algal community composition was only slightly changed by experimentally altered grazer abundance, indicating that it was already adapted for a high grazing pressure. Hence, the diets of herbivores were restricted to vulnerable food organisms such as Mallomonas sp. and heterotrophic flagellates in the water column, and to benthic food sources. 4. At high grazer abundance, the concentration of available phosphorus (PO 4 ‐P) in the water was lower than at low grazer abundances, due to inefficient nutrient regeneration by the copepod herbivores. Hence, in lakes where copepods are dominant grazers, algae suffer both directly from grazing and indirectly from reduced nutrient availability. Article in Journal/Newspaper Antarc* Antarctic Copepods Wiley Online Library Antarctic Freshwater Biology 37 1 45 53 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
1. To test the response of algal communities to altered grazer abundance in lakes lacking efficient predators on herbivores, we performed field and experimental studies in two sub‐Antarctic lakes (South Georgia). 2. The number of algal species in these high latitude lakes is low, and all dominant species have grazer‐resistant adaptations, including spines in three dimensions ( Staurastrum sp.), large size ( Tribonema sp.), a mucus sheet allowing viable passage through the gut ( Chlamydocapsa sp., Elakatothrix sp.) or ability to recruit individuals from the sediment surface ( Mallomonas sp.). 3. Algal community composition was only slightly changed by experimentally altered grazer abundance, indicating that it was already adapted for a high grazing pressure. Hence, the diets of herbivores were restricted to vulnerable food organisms such as Mallomonas sp. and heterotrophic flagellates in the water column, and to benthic food sources. 4. At high grazer abundance, the concentration of available phosphorus (PO 4 ‐P) in the water was lower than at low grazer abundances, due to inefficient nutrient regeneration by the copepod herbivores. Hence, in lakes where copepods are dominant grazers, algae suffer both directly from grazing and indirectly from reduced nutrient availability. |
format |
Article in Journal/Newspaper |
author |
HANSSON, LARS‐ANDERS TRANVIK, LARS |
spellingShingle |
HANSSON, LARS‐ANDERS TRANVIK, LARS Algal species composition and phosphorus recycling at contrasting grazing pressure: an experimental study in sub‐Antarctic lakes with two trophic levels |
author_facet |
HANSSON, LARS‐ANDERS TRANVIK, LARS |
author_sort |
HANSSON, LARS‐ANDERS |
title |
Algal species composition and phosphorus recycling at contrasting grazing pressure: an experimental study in sub‐Antarctic lakes with two trophic levels |
title_short |
Algal species composition and phosphorus recycling at contrasting grazing pressure: an experimental study in sub‐Antarctic lakes with two trophic levels |
title_full |
Algal species composition and phosphorus recycling at contrasting grazing pressure: an experimental study in sub‐Antarctic lakes with two trophic levels |
title_fullStr |
Algal species composition and phosphorus recycling at contrasting grazing pressure: an experimental study in sub‐Antarctic lakes with two trophic levels |
title_full_unstemmed |
Algal species composition and phosphorus recycling at contrasting grazing pressure: an experimental study in sub‐Antarctic lakes with two trophic levels |
title_sort |
algal species composition and phosphorus recycling at contrasting grazing pressure: an experimental study in sub‐antarctic lakes with two trophic levels |
publisher |
Wiley |
publishDate |
1997 |
url |
http://dx.doi.org/10.1046/j.1365-2427.1997.d01-531.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2427.1997.d01-531.x https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2427.1997.d01-531.x |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Copepods |
genre_facet |
Antarc* Antarctic Copepods |
op_source |
Freshwater Biology volume 37, issue 1, page 45-53 ISSN 0046-5070 1365-2427 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1046/j.1365-2427.1997.d01-531.x |
container_title |
Freshwater Biology |
container_volume |
37 |
container_issue |
1 |
container_start_page |
45 |
op_container_end_page |
53 |
_version_ |
1800755117250576384 |