|
Titel |
Interactions between nitrogen deposition, land cover conversion, and climate change determine the contemporary carbon balance of Europe |
VerfasserIn |
G. Churkina, S. Zaehle, J. Hughes, N. Viovy, Y. Chen, M. Jung, B. W. Heumann, N. Ramankutty, M. Heimann, C. Jones |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1726-4170
|
Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 7, no. 9 ; Nr. 7, no. 9 (2010-09-20), S.2749-2764 |
Datensatznummer |
250004969
|
Publikation (Nr.) |
copernicus.org/bg-7-2749-2010.pdf |
|
|
|
Zusammenfassung |
European ecosystems are thought to take up large amounts of carbon, but
neither the rate nor the contributions of the underlying processes are well
known. In the second half of the 20th century, carbon dioxide
concentrations have risen by more that 100 ppm, atmospheric nitrogen
deposition has more than doubled, and European mean temperatures were
increasing by 0.02 °C yr−1. The extents of forest and grasslands have
increased with the respective rates of 5800 km2 yr−1 and 1100 km2 yr−1 as agricultural land has been abandoned at a rate of
7000 km2 yr−1. In this study, we analyze the responses of European land
ecosystems to the aforementioned environmental changes using results from
four process-based ecosystem models: BIOME-BGC, JULES, ORCHIDEE, and O-CN.
The models suggest that European ecosystems sequester carbon at a rate of
56 TgC yr−1 (mean of four models for 1951–2000) with strong interannual
variability (±88 TgC yr−1, average across models) and substantial
inter-model uncertainty (±39 TgC yr−1). Decadal budgets suggest that
there has been a continuous increase in the mean net carbon storage of
ecosystems from 85 TgC yr−1 in 1980s to 108 TgC yr−1 in 1990s, and to
114 TgC yr−1 in 2000–2007. The physiological effect of rising CO2 in
combination with nitrogen deposition and forest re-growth have been
identified as the important explanatory factors for this net carbon storage.
Changes in the growth of woody vegetation are suggested as an important
contributor to the European carbon sink. Simulated ecosystem responses were
more consistent for the two models accounting for terrestrial
carbon-nitrogen dynamics than for the two models which only accounted for
carbon cycling and the effects of land cover change. Studies of the
interactions of carbon-nitrogen dynamics with land use changes are needed to
further improve the quantitative understanding of the driving forces of the
European land carbon balance. |
|
|
Teil von |
|
|
|
|
|
|