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| Titel |
Carbon-, nitrogen- and water-fluxes of agricultural landuse types in the Upper Danube catchment under global change: integrating natural and agroeconomic effects |
| VerfasserIn |
Tim G. Reichenau, Christian W. Klar, Peter Fiener, Karl Schneider |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250042765
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| Zusammenfassung |
| Climate change will not only modify water, carbon and nitrogen fluxes of agricultural
ecosystems as a result of the direct impact of climate parameters. The adaption of
farming practices (e.g. time of management activities, selection of crops) will also
affect theses fluxes. An important driver for changes in agricultural management is
the improvement of economical viability which requires both the optimization of
the spatial distribution of crops over arable land and the adjustment of cultivation
procedures. Thus, investigating climate change effects for agricultural land use types
requires that both, direct natural and indirect anthropogenic effects, must be accounted
for.
The model assembly ’agriculture’ within the DANUBIA decision support system has
been designed to assess interactions between environmental and anthropogenic effects of
climate change. It consists of dynamically interacting models describing plant growth, soil
nitrogen transformation, water- and energy-fluxes. In addition, a farm-actor model simulating
management activities and economic decisions concerning agricultural land use is coupled to
the environmental models. Thus the model assembly ’agriculture’ allows for the analysis of
environmental and agro-economic effects as well as for the feedbacks between these
effects.
In this study changes in transpiration, biomass production and nitrogen uptake for two
different agro-political scenarios area analyzed: a ’baseline’ scenario assuming unchanged
agropolitics and a ’performance’ scenario, where the payment of agricultural subsidies
ends in 2015. Two exemplarily districts with contrasting agricultural land use were
examined. Dingolfing in the northeastern part of the Upper Danube catchment is
dominated by arable land, whereas in Ostallgäu in the southwest region of the catchment
grassland prevails. The model was run for the period 2011 till 2058 assuming a
climate scenario based on the IPPC A1B emission scenario. Ten year averages for the
scenario period from 2049 till 2059 and a reference period from 1996 till 2005 were
compared.
In general, the model results for the reference period shows an increase in biomass
production and an improvement of nitrogen use and water use efficiency for both districts.
Nitrogen uptake is higher in the crop dominated district (Dingolfing) whereas it remains
almost unchanged in the grassland region (Ostallgäu). Transpiration amounts show only
slight changes, increasing in Dingolfing and decreasing in Ostallgäu. A comparison of
the two management scenarios shows that the effects of climate impacts upon the
fluxes are significantly larger than effects arising from farm management decisions. |
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