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Titel |
Effects of land management on large trees and carbon stocks |
VerfasserIn |
P. E. Kauppi, R. A. Birdsey, Y. Pan, A. Ihalainen, P. Nöjd, A. Lehtonen |
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 ; 12, no. 3 ; Nr. 12, no. 3 (2015-02-12), S.855-862 |
Datensatznummer |
250117810
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Publikation (Nr.) |
copernicus.org/bg-12-855-2015.pdf |
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Zusammenfassung |
Large trees are important and unique organisms in forests, providing
ecosystem services including carbon dioxide removal from the atmosphere and
long-term storage. Some reports have raised concerns about the global decline of
large trees. Based on observations from two regions in Finland and three regions
in the United States we report that trends of large trees during recent
decades have been surprisingly variable among regions. In southern Finland,
the growing stock volume of trees larger than 30 cm at breast height
increased nearly five-fold during the second half of the 20th century, yet
more recently ceased to expand. In the United States, large hardwood trees
have become increasingly common in the Northeast since the 1950s, while
large softwood trees declined until the mid 1990s as a consequence of
harvests in the Pacific region, and then rebounded when harvesting there was
reduced. We conclude that in the regions studied, the history of land use
and forest management governs changes of the diameter-class distributions of
tree populations. Large trees have significant benefits; for example, they
can constitute a large proportion of the carbon stock and affect greatly the
carbon density of forests. Large trees usually have deeper roots and long
lifetimes. They affect forest structure and function and provide habitats
for other species. An accumulating stock of large trees in existing forests
may have negligible direct biophysical effects on climate through
transpiration or forest albedo. Understanding changes in the demography of
tree populations makes a contribution to estimating the past impact and
future potential of forests in the global carbon budget and to assessing
other ecosystem services of forests. |
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