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Salvage logging of mountain birch after geometrid outbreaks: Ecological context determines management outcomes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-01)
Outbreaks of pest insects occasionally cause mortality of entire forest stands. Salvage logging of affected stands is
the most common management response to such events. Logging may aid stand recovery by increasing the
production and establishment of saplings, or stimulating the production of basal sprouts in sprouting tree species.
However, the outcome of logging may depend on the ecological ...
Can novel pest outbreaks drive ecosystem transitions in northern-boreal birch forest?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-04)
<p>1.The boreal biome exhibits distinct alternative ecosystem states with high and low levels of tree cover. Insect outbreaks facilitated by climate warming could potentially drive transitions from high to low tree cover states. We investigated whether two key premises for such outbreak‐induced transitions – critical thresholds (tipping points) and positive feedbacks that could maintain alternative ...
Resistance of a sub-arctic bird community to severe forest damage caused by geometrid moth outbreaks
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-05-01)
Outbreaks by geometrid moths periodically cause mass mortality of trees and state changes in understorey vegetation in sub-arctic mountain birch forest in northern Scandinavia. In order to assess the short-term impacts of such disturbance on forest bird communities, we
took bird censuses in forest where almost all birch trees had been killed by moth outbreaks 2–4 years before the study and in ...
Breeding persistence of Slavonian Grebe (Podiceps auritus) at long-term monitoring sites: predictors of a steep decline at the northern European range limit
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06-10)
The Slavonian Grebe (Podiceps auritus) has its
European northern range limit in northern Norway, and is a
species of national conservation concern due to its small
population size and unknown population trend. Long-term
monitoring at the range limit suggests breeding site use is
in decline. We used annual occupancy data from 104
breeding lakes monitored since 1991 in northern Norway to
investigate ...
Identification and Evaluation of 21 Novel Microsatellite Markers from the Autumnal Moth (Epirrita autumnata) (Lepidoptera: Geometridae)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-17)
The autumnal moth (Epirrita autumnata) is a cyclically outbreaking forest Lepidoptera with circumpolar distribution and substantial impact on Northern ecosystems. We have isolated 21 microsatellites from the species to facilitate population genetic studies of population cycles, outbreaks, and crashes. First, PCR primers and PCR conditions were developed to amplify 19 trinucleotide loci and two ...
Numerical responses of saproxylic beetles to rapid increases in dead wood availability following geometrid moth outbreaks in sub-arctic mountain birch forest
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
Saproxylic insects play an important part in decomposing dead wood in healthy forest ecosystems, but little is known about their role in the aftermath of large-scale forest mortality caused by pest insect outbreaks. We used window traps to study short-term changes in the abundance and community structure of saproxylic beetles following extensive mortality of mountain birch in sub-arctic northern ...
How rapidly do invasive birch forest geometrids recruit larval parasitoids? Insights from comparison with a sympatric native geometrid
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
Two related issues in studies of biological invasions are how quickly the enemy complexes of invasive species become as species-rich and efficient as those of native species and how important enemy release is for the establishment and spread of invaders. We addressed these issues for the geometrid moths Operophtera brumata and Agriopis aurantiaria, who invaded the coastal mountain birch forest ...
Outbreaks by canopy-feeding geometrid moth cause state-dependent shifts in understorey plant communities
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
The increased spread of insect outbreaks is
among the most severe impacts of climate warming predicted
for northern boreal forest ecosystems. Compound
disturbances by insect herbivores can cause sharp transitions
between vegetation states with implications for ecosystem
productivity and climate feedbacks. By analysing
vegetation plots prior to and immediately after a severe and
widespread ...
High goose abundance reduces nest predation risk in a simple rodent-free high-Arctic ecosystem
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-13)
Breeding geese are the preferred prey of the Arctic fox Vulpes lagopus in the high-Arctic Svalbard archipelago. According to the <i>apparent competition hypothesis (ACH)</i>, less-abundant prey species (e.g. ptarmigan, waders and small passerines) will experience higher predation rates when breeding in association with the more common prey (geese), due to spill-over predation by the shared predator. ...
A pioneering pest: the winter moth (Operophtera brumata) is expanding its outbreak range into Low Arctic shrub tundra
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-01)
Climate warming allows generalist boreal consumers to expand into Arctic ecosystems. We present experimental and observational field data showing that a generalist boreal insect pest—the winter moth (Operophtera brumata Linnaeus, 1758)—is expanding its outbreak range out of the northern boreal mountain birch forest in northeast Fennoscandia and into the adjacent Low Arctic shrub tundra. This is the ...