Experimental evidence for herbivore limitation of the treeline
The treeline ecotone divides forest from open alpine or arctic vegetation states. Treelines are generally perceived to be temperature limited. The role of herbivores in limiting the treeline is more controversial, as experimental evidence from relevant large scales is lacking. Here we quantify the i...
Published in: | Ecology |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2010
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1890/09-2300.1 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1890%2F09-2300.1 https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1890/09-2300.1 |
id |
crwiley:10.1890/09-2300.1 |
---|---|
record_format |
openpolar |
spelling |
crwiley:10.1890/09-2300.1 2024-09-09T19:26:07+00:00 Experimental evidence for herbivore limitation of the treeline Speed, James D. M. Austrheim, Gunnar Hester, Alison J. Mysterud, Atle 2010 http://dx.doi.org/10.1890/09-2300.1 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1890%2F09-2300.1 https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1890/09-2300.1 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Ecology volume 91, issue 11, page 3414-3420 ISSN 0012-9658 1939-9170 journal-article 2010 crwiley https://doi.org/10.1890/09-2300.1 2024-08-06T04:16:34Z The treeline ecotone divides forest from open alpine or arctic vegetation states. Treelines are generally perceived to be temperature limited. The role of herbivores in limiting the treeline is more controversial, as experimental evidence from relevant large scales is lacking. Here we quantify the impact of different experimentally controlled herbivore densities on the recruitment and survival of birch Betula pubescens tortuosa along an altitudinal gradient in the mountains of southern Norway. After eight years of summer grazing in large‐scale enclosures at densities of 0, 25, and 80 sheep/km 2 , birch recruited within the whole altitudinal range of ungrazed enclosures, but recruitment was rarer in enclosures with low‐density sheep and was largely limited to within the treeline in enclosures with high‐density sheep. In contrast, the distribution of saplings (birch older than the experiment) did not differ between grazing treatments, suggesting that grazing sheep primarily limit the establishment of new tree recruits rather than decrease the survival of existing individuals. This study provides direct experimental evidence that herbivores can limit the treeline below its potential at the landscape scale and even at low herbivore densities in this climatic zone. Land use changes should thus be considered in addition to climatic changes as potential drivers of ecotone shifts. Article in Journal/Newspaper Arctic Wiley Online Library Arctic Norway Ecology 91 11 3414 3420 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
The treeline ecotone divides forest from open alpine or arctic vegetation states. Treelines are generally perceived to be temperature limited. The role of herbivores in limiting the treeline is more controversial, as experimental evidence from relevant large scales is lacking. Here we quantify the impact of different experimentally controlled herbivore densities on the recruitment and survival of birch Betula pubescens tortuosa along an altitudinal gradient in the mountains of southern Norway. After eight years of summer grazing in large‐scale enclosures at densities of 0, 25, and 80 sheep/km 2 , birch recruited within the whole altitudinal range of ungrazed enclosures, but recruitment was rarer in enclosures with low‐density sheep and was largely limited to within the treeline in enclosures with high‐density sheep. In contrast, the distribution of saplings (birch older than the experiment) did not differ between grazing treatments, suggesting that grazing sheep primarily limit the establishment of new tree recruits rather than decrease the survival of existing individuals. This study provides direct experimental evidence that herbivores can limit the treeline below its potential at the landscape scale and even at low herbivore densities in this climatic zone. Land use changes should thus be considered in addition to climatic changes as potential drivers of ecotone shifts. |
format |
Article in Journal/Newspaper |
author |
Speed, James D. M. Austrheim, Gunnar Hester, Alison J. Mysterud, Atle |
spellingShingle |
Speed, James D. M. Austrheim, Gunnar Hester, Alison J. Mysterud, Atle Experimental evidence for herbivore limitation of the treeline |
author_facet |
Speed, James D. M. Austrheim, Gunnar Hester, Alison J. Mysterud, Atle |
author_sort |
Speed, James D. M. |
title |
Experimental evidence for herbivore limitation of the treeline |
title_short |
Experimental evidence for herbivore limitation of the treeline |
title_full |
Experimental evidence for herbivore limitation of the treeline |
title_fullStr |
Experimental evidence for herbivore limitation of the treeline |
title_full_unstemmed |
Experimental evidence for herbivore limitation of the treeline |
title_sort |
experimental evidence for herbivore limitation of the treeline |
publisher |
Wiley |
publishDate |
2010 |
url |
http://dx.doi.org/10.1890/09-2300.1 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1890%2F09-2300.1 https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1890/09-2300.1 |
geographic |
Arctic Norway |
geographic_facet |
Arctic Norway |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Ecology volume 91, issue 11, page 3414-3420 ISSN 0012-9658 1939-9170 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1890/09-2300.1 |
container_title |
Ecology |
container_volume |
91 |
container_issue |
11 |
container_start_page |
3414 |
op_container_end_page |
3420 |
_version_ |
1809895791584608256 |