Ecosystem impacts of a range expanding forest defoliator at the Forest-Tundra Ecotone. Ecosystems
ABSTRACT Insect outbreaks in northern-boreal forests are expected to intensify owing to climate warming, but our understanding of direct and cascading impacts of insect outbreaks on forest ecosystem functioning is deficient. The duration and severity of outbreaks by geometrid moths in northern Fenno...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.1040.7533 2023-05-15T16:06:05+02:00 Ecosystem impacts of a range expanding forest defoliator at the Forest-Tundra Ecotone. Ecosystems Jane U Jepsen Martin Biuw Rolf A Ims Lauri Kapari Tino Schott Ole Petter L Vindstad Snorre B Hagen The Pennsylvania State University CiteSeerX Archives 2012 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1040.7533 http://www.birchmoth.no/wp-content/uploads/2015/03/Jepsen-et-al.-2013.-Ecosystems.-Ecosystem-impacts-of-a-range-expanding-forest-defoliator-at-the-forest-tundra-ecotone.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1040.7533 http://www.birchmoth.no/wp-content/uploads/2015/03/Jepsen-et-al.-2013.-Ecosystems.-Ecosystem-impacts-of-a-range-expanding-forest-defoliator-at-the-forest-tundra-ecotone.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.birchmoth.no/wp-content/uploads/2015/03/Jepsen-et-al.-2013.-Ecosystems.-Ecosystem-impacts-of-a-range-expanding-forest-defoliator-at-the-forest-tundra-ecotone.pdf text 2012 ftciteseerx 2020-03-08T01:24:13Z ABSTRACT Insect outbreaks in northern-boreal forests are expected to intensify owing to climate warming, but our understanding of direct and cascading impacts of insect outbreaks on forest ecosystem functioning is deficient. The duration and severity of outbreaks by geometrid moths in northern Fennoscandian mountain birch forests have been shown to be accentuated by a recent climatemediated range expansion, in particular of winter moth (Operophtera brumata). Here, we assess the effect of moth outbreak severity, quantified from satellite-based defoliation maps, on the state of understory vegetation and the abundance of key vertebrate herbivores in mountain birch forest in northern Norway. We show that the most recent moth outbreak caused a regional-scale state change to the understory vegetation, mainly due to a shift in dominance from the allelopathic and unpalatable dwarf-shrub Empetrum nigrum to the productive and palatable grass Avenella flexuosa. Both these central understory plant species responded significantly and nonlinearly to increasing outbreak severity. We further provide evidence that the effects of the outbreak on understory vegetation cascaded to cause strong but opposite impacts on the abundance of the two most common herbivore groups. Rodents increased with defoliation, largely mirroring the increase in A. flexuosa, whereas ungulate abundance instead showed a decreasing trend. Our analyses also suggest that the response of understory vegetation to defoliation may depend on the initial state of the forest, with poorer forest types potentially allowing stronger responses to defoliation. Text Empetrum nigrum Fennoscandian Northern Norway Tundra Unknown Norway |
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ftciteseerx |
language |
English |
description |
ABSTRACT Insect outbreaks in northern-boreal forests are expected to intensify owing to climate warming, but our understanding of direct and cascading impacts of insect outbreaks on forest ecosystem functioning is deficient. The duration and severity of outbreaks by geometrid moths in northern Fennoscandian mountain birch forests have been shown to be accentuated by a recent climatemediated range expansion, in particular of winter moth (Operophtera brumata). Here, we assess the effect of moth outbreak severity, quantified from satellite-based defoliation maps, on the state of understory vegetation and the abundance of key vertebrate herbivores in mountain birch forest in northern Norway. We show that the most recent moth outbreak caused a regional-scale state change to the understory vegetation, mainly due to a shift in dominance from the allelopathic and unpalatable dwarf-shrub Empetrum nigrum to the productive and palatable grass Avenella flexuosa. Both these central understory plant species responded significantly and nonlinearly to increasing outbreak severity. We further provide evidence that the effects of the outbreak on understory vegetation cascaded to cause strong but opposite impacts on the abundance of the two most common herbivore groups. Rodents increased with defoliation, largely mirroring the increase in A. flexuosa, whereas ungulate abundance instead showed a decreasing trend. Our analyses also suggest that the response of understory vegetation to defoliation may depend on the initial state of the forest, with poorer forest types potentially allowing stronger responses to defoliation. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Jane U Jepsen Martin Biuw Rolf A Ims Lauri Kapari Tino Schott Ole Petter L Vindstad Snorre B Hagen |
spellingShingle |
Jane U Jepsen Martin Biuw Rolf A Ims Lauri Kapari Tino Schott Ole Petter L Vindstad Snorre B Hagen Ecosystem impacts of a range expanding forest defoliator at the Forest-Tundra Ecotone. Ecosystems |
author_facet |
Jane U Jepsen Martin Biuw Rolf A Ims Lauri Kapari Tino Schott Ole Petter L Vindstad Snorre B Hagen |
author_sort |
Jane U Jepsen |
title |
Ecosystem impacts of a range expanding forest defoliator at the Forest-Tundra Ecotone. Ecosystems |
title_short |
Ecosystem impacts of a range expanding forest defoliator at the Forest-Tundra Ecotone. Ecosystems |
title_full |
Ecosystem impacts of a range expanding forest defoliator at the Forest-Tundra Ecotone. Ecosystems |
title_fullStr |
Ecosystem impacts of a range expanding forest defoliator at the Forest-Tundra Ecotone. Ecosystems |
title_full_unstemmed |
Ecosystem impacts of a range expanding forest defoliator at the Forest-Tundra Ecotone. Ecosystems |
title_sort |
ecosystem impacts of a range expanding forest defoliator at the forest-tundra ecotone. ecosystems |
publishDate |
2012 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1040.7533 http://www.birchmoth.no/wp-content/uploads/2015/03/Jepsen-et-al.-2013.-Ecosystems.-Ecosystem-impacts-of-a-range-expanding-forest-defoliator-at-the-forest-tundra-ecotone.pdf |
geographic |
Norway |
geographic_facet |
Norway |
genre |
Empetrum nigrum Fennoscandian Northern Norway Tundra |
genre_facet |
Empetrum nigrum Fennoscandian Northern Norway Tundra |
op_source |
http://www.birchmoth.no/wp-content/uploads/2015/03/Jepsen-et-al.-2013.-Ecosystems.-Ecosystem-impacts-of-a-range-expanding-forest-defoliator-at-the-forest-tundra-ecotone.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1040.7533 http://www.birchmoth.no/wp-content/uploads/2015/03/Jepsen-et-al.-2013.-Ecosystems.-Ecosystem-impacts-of-a-range-expanding-forest-defoliator-at-the-forest-tundra-ecotone.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766402006429204480 |