Population dynamics of tundra-living grey-sided voles
This thesis deals with the dynamics of tundra living voles with emphasis on the most common one, the grey-sided vole (Clethrionomys rufocanus). The tundra area chosen for the study was Finnmarksvidda, a vast flatland in northernmost Norway. All small mammal herbivores in the area showed dramatic flu...
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Ekologi och geovetenskap
2003
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ftumeauniv:oai:DiVA.org:umu-187 2023-10-09T21:51:27+02:00 Population dynamics of tundra-living grey-sided voles Ekerholm, Per 2003 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-187 eng eng Ekologi och geovetenskap http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-187 urn:isbn:91-7305-300-7 info:eu-repo/semantics/openAccess Ecology Population dynamics Tundra Grey-sided vole Cycles Vole specialist predators Ekologi Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2003 ftumeauniv 2023-09-22T13:47:29Z This thesis deals with the dynamics of tundra living voles with emphasis on the most common one, the grey-sided vole (Clethrionomys rufocanus). The tundra area chosen for the study was Finnmarksvidda, a vast flatland in northernmost Norway. All small mammal herbivores in the area showed dramatic fluctuations, and field experiment were conducted in order to elucidate these density fluctuations. The specific subjects addressed included: 1/ Temporal and spatial appearance of density fluctuations of voles and lemmings in the area, 2/ The generality of the density patterns observed, 3/ The impact of predation by vole predators during summertime, 4/ The impact of grey-sided vole grazing on food plants of different preference in a predator free environment, in the presence and absence of extra food, and 5/ The impact of food availability on density and demography of grey-sided voles in a predator free environment. The results achieved showed that voles in the slope and lowland had cyclic density fluctuations with 5 years duration. The cycles consisted of four phases: an increase phase, a peak phase, a decline phase and a crash phase. In the unproductive lowland and on the moderately productive slope, small pockets of productive habitats seemed to work as “triggers” for the cycles. The lemming fluctuations in the upper plateau (separated from the slope by a steep zone of boulders) differed markedly from the vole patterns in the lowland. Only two lemming peaks were recorded in twenty years. Both peaks had very short increase phases, a knife-sharppeak phase and no decline phase before the crash. A comparison between our results and lemming and vole populations from two other areas in Fennoscandia revealed the same difference in fluctuation pattern between lemmings and voles as seen in our area. This results suggests that lemmings in barren tundra highlands and voles in slightly more productive tundra lowlands are regulated by different mechanisms. The exclusion of vole predators from vole populations during summertime led ... Doctoral or Postdoctoral Thesis Fennoscandia Finnmarksvidda Tundra Umeå University: Publications (DiVA) Norway Finnmarksvidda ENVELOPE(23.744,23.744,69.113,69.113) |
institution |
Open Polar |
collection |
Umeå University: Publications (DiVA) |
op_collection_id |
ftumeauniv |
language |
English |
topic |
Ecology Population dynamics Tundra Grey-sided vole Cycles Vole specialist predators Ekologi |
spellingShingle |
Ecology Population dynamics Tundra Grey-sided vole Cycles Vole specialist predators Ekologi Ekerholm, Per Population dynamics of tundra-living grey-sided voles |
topic_facet |
Ecology Population dynamics Tundra Grey-sided vole Cycles Vole specialist predators Ekologi |
description |
This thesis deals with the dynamics of tundra living voles with emphasis on the most common one, the grey-sided vole (Clethrionomys rufocanus). The tundra area chosen for the study was Finnmarksvidda, a vast flatland in northernmost Norway. All small mammal herbivores in the area showed dramatic fluctuations, and field experiment were conducted in order to elucidate these density fluctuations. The specific subjects addressed included: 1/ Temporal and spatial appearance of density fluctuations of voles and lemmings in the area, 2/ The generality of the density patterns observed, 3/ The impact of predation by vole predators during summertime, 4/ The impact of grey-sided vole grazing on food plants of different preference in a predator free environment, in the presence and absence of extra food, and 5/ The impact of food availability on density and demography of grey-sided voles in a predator free environment. The results achieved showed that voles in the slope and lowland had cyclic density fluctuations with 5 years duration. The cycles consisted of four phases: an increase phase, a peak phase, a decline phase and a crash phase. In the unproductive lowland and on the moderately productive slope, small pockets of productive habitats seemed to work as “triggers” for the cycles. The lemming fluctuations in the upper plateau (separated from the slope by a steep zone of boulders) differed markedly from the vole patterns in the lowland. Only two lemming peaks were recorded in twenty years. Both peaks had very short increase phases, a knife-sharppeak phase and no decline phase before the crash. A comparison between our results and lemming and vole populations from two other areas in Fennoscandia revealed the same difference in fluctuation pattern between lemmings and voles as seen in our area. This results suggests that lemmings in barren tundra highlands and voles in slightly more productive tundra lowlands are regulated by different mechanisms. The exclusion of vole predators from vole populations during summertime led ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Ekerholm, Per |
author_facet |
Ekerholm, Per |
author_sort |
Ekerholm, Per |
title |
Population dynamics of tundra-living grey-sided voles |
title_short |
Population dynamics of tundra-living grey-sided voles |
title_full |
Population dynamics of tundra-living grey-sided voles |
title_fullStr |
Population dynamics of tundra-living grey-sided voles |
title_full_unstemmed |
Population dynamics of tundra-living grey-sided voles |
title_sort |
population dynamics of tundra-living grey-sided voles |
publisher |
Ekologi och geovetenskap |
publishDate |
2003 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-187 |
long_lat |
ENVELOPE(23.744,23.744,69.113,69.113) |
geographic |
Norway Finnmarksvidda |
geographic_facet |
Norway Finnmarksvidda |
genre |
Fennoscandia Finnmarksvidda Tundra |
genre_facet |
Fennoscandia Finnmarksvidda Tundra |
op_relation |
http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-187 urn:isbn:91-7305-300-7 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1779314554990231552 |