The primacy of bears as seed dispersers in salmon‐bearing ecosystems
Abstract Salmon–bear ecosystems that historically existed throughout most of the northern temperate and boreal regions of planet earth now persist only in the North Pacific. Extensive research on salmon–bear interactions has focused on the role that bears (Ursus arctos and U. americanus) play in pro...
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ftdoajarticles:oai:doaj.org/article:93d2dda9ed884191897db5c54e107dab 2023-05-15T18:42:14+02:00 The primacy of bears as seed dispersers in salmon‐bearing ecosystems Laurie E. F. Harrer Taal Levi 2018-01-01T00:00:00Z https://doi.org/10.1002/ecs2.2076 https://doaj.org/article/93d2dda9ed884191897db5c54e107dab EN eng Wiley https://doi.org/10.1002/ecs2.2076 https://doaj.org/toc/2150-8925 2150-8925 doi:10.1002/ecs2.2076 https://doaj.org/article/93d2dda9ed884191897db5c54e107dab Ecosphere, Vol 9, Iss 1, Pp n/a-n/a (2018) Alaska devil's club interference competition mutualism seed dispersal Ecology QH540-549.5 article 2018 ftdoajarticles https://doi.org/10.1002/ecs2.2076 2022-12-30T23:43:39Z Abstract Salmon–bear ecosystems that historically existed throughout most of the northern temperate and boreal regions of planet earth now persist only in the North Pacific. Extensive research on salmon–bear interactions has focused on the role that bears (Ursus arctos and U. americanus) play in provisioning terrestrial systems with marine‐derived nutrients, but little attention has been paid to how the much higher bear population densities in salmon‐bearing ecosystems then affect ecological communities. Salmon‐supported brown bears secondarily consume large quantities of fruit and may thus serve as important seed dispersers, but the relative seed dispersal services provided by bears and birds are unknown. We sought to (1) quantify the number of seeds dispersed by bears relative to birds, and (2) by brown bears relative to black bears, and to (3) assess whether the two sympatric bears temporally partition berry resources as a result of competitively dominant brown bears switching to feed on salmon, thus opening niche space for black bears. We used a combination of motion‐triggered camera traps and environmental DNA (eDNA) from residual saliva to quantify the roles of birds, black bears, and brown bears as seed dispersers of devil's club (Oplopanax horridus), the dominant understory shrub at our field site in northern southeast Alaska. Brown bears were the numerically dominant seed dispersers, particularly before salmon became widely available, after which black bears became common seed dispersers, likely due to alleviation of interference competition. Birds accounted for only a small fraction of seed dispersal. This is the first demonstration of a temperate plant being primarily dispersed by mammalian gut passage. Our results suggest that bears are uniquely important seed dispersers, which may influence plant community composition in salmon‐bearing ecosystems. Article in Journal/Newspaper Ursus arctos Alaska Directory of Open Access Journals: DOAJ Articles Pacific Ecosphere 9 1 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Alaska devil's club interference competition mutualism seed dispersal Ecology QH540-549.5 |
spellingShingle |
Alaska devil's club interference competition mutualism seed dispersal Ecology QH540-549.5 Laurie E. F. Harrer Taal Levi The primacy of bears as seed dispersers in salmon‐bearing ecosystems |
topic_facet |
Alaska devil's club interference competition mutualism seed dispersal Ecology QH540-549.5 |
description |
Abstract Salmon–bear ecosystems that historically existed throughout most of the northern temperate and boreal regions of planet earth now persist only in the North Pacific. Extensive research on salmon–bear interactions has focused on the role that bears (Ursus arctos and U. americanus) play in provisioning terrestrial systems with marine‐derived nutrients, but little attention has been paid to how the much higher bear population densities in salmon‐bearing ecosystems then affect ecological communities. Salmon‐supported brown bears secondarily consume large quantities of fruit and may thus serve as important seed dispersers, but the relative seed dispersal services provided by bears and birds are unknown. We sought to (1) quantify the number of seeds dispersed by bears relative to birds, and (2) by brown bears relative to black bears, and to (3) assess whether the two sympatric bears temporally partition berry resources as a result of competitively dominant brown bears switching to feed on salmon, thus opening niche space for black bears. We used a combination of motion‐triggered camera traps and environmental DNA (eDNA) from residual saliva to quantify the roles of birds, black bears, and brown bears as seed dispersers of devil's club (Oplopanax horridus), the dominant understory shrub at our field site in northern southeast Alaska. Brown bears were the numerically dominant seed dispersers, particularly before salmon became widely available, after which black bears became common seed dispersers, likely due to alleviation of interference competition. Birds accounted for only a small fraction of seed dispersal. This is the first demonstration of a temperate plant being primarily dispersed by mammalian gut passage. Our results suggest that bears are uniquely important seed dispersers, which may influence plant community composition in salmon‐bearing ecosystems. |
format |
Article in Journal/Newspaper |
author |
Laurie E. F. Harrer Taal Levi |
author_facet |
Laurie E. F. Harrer Taal Levi |
author_sort |
Laurie E. F. Harrer |
title |
The primacy of bears as seed dispersers in salmon‐bearing ecosystems |
title_short |
The primacy of bears as seed dispersers in salmon‐bearing ecosystems |
title_full |
The primacy of bears as seed dispersers in salmon‐bearing ecosystems |
title_fullStr |
The primacy of bears as seed dispersers in salmon‐bearing ecosystems |
title_full_unstemmed |
The primacy of bears as seed dispersers in salmon‐bearing ecosystems |
title_sort |
primacy of bears as seed dispersers in salmon‐bearing ecosystems |
publisher |
Wiley |
publishDate |
2018 |
url |
https://doi.org/10.1002/ecs2.2076 https://doaj.org/article/93d2dda9ed884191897db5c54e107dab |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Ursus arctos Alaska |
genre_facet |
Ursus arctos Alaska |
op_source |
Ecosphere, Vol 9, Iss 1, Pp n/a-n/a (2018) |
op_relation |
https://doi.org/10.1002/ecs2.2076 https://doaj.org/toc/2150-8925 2150-8925 doi:10.1002/ecs2.2076 https://doaj.org/article/93d2dda9ed884191897db5c54e107dab |
op_doi |
https://doi.org/10.1002/ecs2.2076 |
container_title |
Ecosphere |
container_volume |
9 |
container_issue |
1 |
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1766231865255002112 |