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| Titel |
Emissions of BVOC from lodgepole pine in response to mountain pine beetle attack in high and low mortality forest stands |
| VerfasserIn |
T. R. Duhl, D. Gochis, A. Guenther, S. Ferrenberg, E. Pendall |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 1 ; Nr. 10, no. 1 (2013-01-25), S.483-499 |
| Datensatznummer |
250017484
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| Publikation (Nr.) |
 copernicus.org/bg-10-483-2013.pdf |
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| Zusammenfassung |
| In this screening study, biogenic volatile organic compound (BVOC) emissions
from intact branches of lodgepole pine (Pinus contorta) trees were measured from
trees at two forested sites that have been impacted differently by the
mountain pine beetle (MPB), with one having higher mortality and the other
with lower mortality. Differences in the amounts and chemical diversity of
BVOC between the two sites and from apparently healthy trees versus trees in
different stages of MPB attack are presented, as well as (for one site)
observed seasonal variability in emissions. A brief comparison is made of
geological and climatic characteristics as well as prior disturbances (both
natural and man-made) at each site. Trees sampled at the site experiencing
high MPB-related tree mortality had lower chemodiversity in terms of
monoterpene (MT) emission profiles, while profiles were more diverse at the
lower-mortality site. Also at the higher-mortality site, MPB-infested trees
in various stages of decline had lower emissions of sesquiterpenes (SQTs)
compared to healthy trees, while at the site with lower mortality,
MPB-survivors had significantly higher SQT emissions during part of the
growing season when compared to both uninfested and newly infested trees.
SQT profiles differed between the two sites and, like monoterpene and
oxygenated VOC profiles, varied through the season. For the low-mortality
site in which repeated measurements were made over the course of the early
summer–late fall, higher chemical diversity was observed in early- compared
to late-season measurements for all compound classes investigated (MT,
oxygenated VOC, and SQT), with the amount of change appearing to correlate
to the MPB status of the trees studied. Emissions of 2-methyl-3-buten-2-ol (MBO)
had a distinct seasonal signal but were not much different between healthy
or infested trees, except in trees with dead needles, from which emissions
of this compound were negligible, and in late-season MPB survivors, in which
they were higher than in newly infested or uninfested trees. Emissions of
SQT were significantly higher in the MPB survivors during both mid- and
late-season sampling at the low-mortality site. The changes in emissions
could have implications for regional air quality and climate through changes
in ozone and aerosol distributions, although this study was designed as a
preliminary screening effort and not enough individuals were sampled for all
of the observed differences to be statistically demonstrated. Despite this,
the compelling differences in emissions observed between the sites and
individual trees with differing MPB-infestation statuses and the potential
impacts these have on regional atmospheric chemistry argue for further
research in this topic. |
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