 |
| Titel |
Effects of changing land use and climate on soil respiration and its components in mountain grassland |
| VerfasserIn |
M. Bahn, M. Gort, V. Gruber, T. Ladreiter-Knauss, M. Schmitt |
| Konferenz |
EGU General Assembly 2009
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250027314
|
|
|
|
|
|
| Zusammenfassung |
| In mountain areas changes in land use and climate have been more pronounced than in many
other parts of Europe. Soil respiration is the largest source of CO2 in terrestrial ecosystems
and exhibits particularly high rates in Central European mountain meadows. Based on a
multi-annual dataset and a number of ecosystem manipulation experiments we analyse
possible effects of land management, land use and climate change on soil respiration
and its components (including root, autotrophic and heterotrophic microbial) in
mountain grasslands in the Austrian Central Alps. Our results indicate that 1) land
management and land use change affect soil CO2 production and diffusion across the
soil profile, as well as specific respiratory rates and the relative importance of the
source components, 2) in spite of a rapid transfer and respiratory utilisation of fresh
photosynthates in the plant-soil system, soil CO2 fluxes in mountain grasslands are well
buffered against short-term changes in assimilate supply, as could be induced e.g.
by land management practises or weather extremes, and 3) while climate affects
soil respiratory fluxes via gross primary productivity at an annual scale, droughts
occurring at shorter timescales have only minor effects on soil respiration and cause
disproportionately larger reductions of canopy photosynthesis. In case the observed
decoupling of soil CO2 fluxes from photosynthesis in response to land management and
climate changes is to persist also at longer timescales, it might affect the ecosystem
C balance significantly and result in a net C loss from mountain grassland soils. |
|
|
|
|
|
|