Invasion of top and intermediate consumers in a size structured fish community
In this thesis I have investigated the effects of invading top and intermediate consumers in a size-structured fish community, using a combination of field studies, a lake invasion experiment and smaller scale pond and aquaria experiments. The lake invasion experiment was based on introductions of a...
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Institutionen för ekologi, miljö och geovetenskap
2010
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ftumeauniv:oai:DiVA.org:umu-37995 2023-10-09T21:49:00+02:00 Invasion of top and intermediate consumers in a size structured fish community Invasion av toppredatorer och intermediära konsumenter i ett storleksstrukturerat fisksamhälle Ask, Per 2010 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-37995 eng eng Institutionen för ekologi, miljö och geovetenskap Umeå : Umeå universitet, Institutionen för ekologi, miljö och geovetenskap http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-37995 urn:isbn:978-91-7459-119-4 info:eu-repo/semantics/openAccess Invasion intraguild predation size-structure cannibalism climate temperature Arctic char ninespine stickleback Ecology Ekologi Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2010 ftumeauniv 2023-09-22T13:49:37Z In this thesis I have investigated the effects of invading top and intermediate consumers in a size-structured fish community, using a combination of field studies, a lake invasion experiment and smaller scale pond and aquaria experiments. The lake invasion experiment was based on introductions of an intermediate consumer, ninespine stickleback (Pungitius pungitius L.), in to allopatric populations of an omnivorous top predator, Arctic char (Salvelinus alpinus L.). The invasion experiment was performed in two tundra lakes and in two birch forest lakes to investigate the effect of climate on the invasion success. I found that the effect of sticklebacks on char was size dependent. Small char suffered reduced growth from resource competition with sticklebacks whereas the maximum size of adult char increased from the addition of a larger prey resource, stickleback. The negative effect of sticklebacks on the growth of small char suggests that sticklebacks may be a better resource competitor than char, which was also supported by the pond and aquaria experiments. The pond experiments also suggested that char were more efficient cannibals than interspecific predators on sticklebacks. Cannibalism in char may limit the recruitment of char and decrease both their predatory and competitive effect on coexisting species and thereby also promote the coexistence of char and sticklebacks. The successful invasion by sticklebacks and their subsequent increases in density suggest that the absence of sticklebacks in char lakes in this region is not caused by biotic interactions with char. Instead, it may be suggested that co-occurrence of sticklebacks and char in the region is limited by dispersal. The char – stickleback system resembles an intraguild predation system with char as the top consumer and stickleback as the intermediate consumer. The effects of the stickleback invasion is also contrasted with a field study of a northern pike (Esox lucius L.) invasion into a system with coexisting char and stickleback, where pike can be ... Doctoral or Postdoctoral Thesis Arctic Esox lucius Northern pike Salvelinus alpinus Tundra Umeå University: Publications (DiVA) Arctic |
institution |
Open Polar |
collection |
Umeå University: Publications (DiVA) |
op_collection_id |
ftumeauniv |
language |
English |
topic |
Invasion intraguild predation size-structure cannibalism climate temperature Arctic char ninespine stickleback Ecology Ekologi |
spellingShingle |
Invasion intraguild predation size-structure cannibalism climate temperature Arctic char ninespine stickleback Ecology Ekologi Ask, Per Invasion of top and intermediate consumers in a size structured fish community |
topic_facet |
Invasion intraguild predation size-structure cannibalism climate temperature Arctic char ninespine stickleback Ecology Ekologi |
description |
In this thesis I have investigated the effects of invading top and intermediate consumers in a size-structured fish community, using a combination of field studies, a lake invasion experiment and smaller scale pond and aquaria experiments. The lake invasion experiment was based on introductions of an intermediate consumer, ninespine stickleback (Pungitius pungitius L.), in to allopatric populations of an omnivorous top predator, Arctic char (Salvelinus alpinus L.). The invasion experiment was performed in two tundra lakes and in two birch forest lakes to investigate the effect of climate on the invasion success. I found that the effect of sticklebacks on char was size dependent. Small char suffered reduced growth from resource competition with sticklebacks whereas the maximum size of adult char increased from the addition of a larger prey resource, stickleback. The negative effect of sticklebacks on the growth of small char suggests that sticklebacks may be a better resource competitor than char, which was also supported by the pond and aquaria experiments. The pond experiments also suggested that char were more efficient cannibals than interspecific predators on sticklebacks. Cannibalism in char may limit the recruitment of char and decrease both their predatory and competitive effect on coexisting species and thereby also promote the coexistence of char and sticklebacks. The successful invasion by sticklebacks and their subsequent increases in density suggest that the absence of sticklebacks in char lakes in this region is not caused by biotic interactions with char. Instead, it may be suggested that co-occurrence of sticklebacks and char in the region is limited by dispersal. The char – stickleback system resembles an intraguild predation system with char as the top consumer and stickleback as the intermediate consumer. The effects of the stickleback invasion is also contrasted with a field study of a northern pike (Esox lucius L.) invasion into a system with coexisting char and stickleback, where pike can be ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Ask, Per |
author_facet |
Ask, Per |
author_sort |
Ask, Per |
title |
Invasion of top and intermediate consumers in a size structured fish community |
title_short |
Invasion of top and intermediate consumers in a size structured fish community |
title_full |
Invasion of top and intermediate consumers in a size structured fish community |
title_fullStr |
Invasion of top and intermediate consumers in a size structured fish community |
title_full_unstemmed |
Invasion of top and intermediate consumers in a size structured fish community |
title_sort |
invasion of top and intermediate consumers in a size structured fish community |
publisher |
Institutionen för ekologi, miljö och geovetenskap |
publishDate |
2010 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-37995 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Esox lucius Northern pike Salvelinus alpinus Tundra |
genre_facet |
Arctic Esox lucius Northern pike Salvelinus alpinus Tundra |
op_relation |
http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-37995 urn:isbn:978-91-7459-119-4 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1779312041676242944 |