Autori: Pinay G., Gumiero B. Tabacchi E. Gimenez O. Planty-Tabacchi A. M., Hefting M., Burt T., Black V., Nilsson C. Iordache V., Bureau F. Vought L., Petts G., Décamps H.

Editorial: Blackwell Publishing, Freshwater Biology, 52, p.252-266, 2007.

Rezumat:

1. Denitrification in floodplain soils is one of the main biological processes emitting and reducing nitrous oxide, a greenhouse gas, and the main process responsible for the buffering capacity of riparian zones against diffuse nitrate pollution.
2. The aim of this study was to measure denitrification rates under a wide range of current climatic conditions and hydrological regimes in Europe (from latitude 64o N to latitude 42o N – and from longitude 2° W to longitude 25° E), in order to determine the response patterns of this microbial process under different climatic and hydrological conditions, and to identify denitrification proxies robust enough to be used at the European scale.
3. Denitrification activity was significant in all the floodplain soils studied whatever the latitude. However, we found an increase in rates of an order of magnitude from high to mid latitudes. Maximum rates (above 30 g N m-2 month-1) were measured in the maritime conditions of the Trent floodplain. These rates are similar to mineralization rates measured in alluvial soils and of the same order of magnitude as the amount of N stored in herbaceous plants in alluvial soils.
4. We used Multivariate Adaptative Regression Splines (MARS) to relate the response variable denitrification with five relevant predictors, namely soil moisture, temperature, silt plus clay, nitrate content and herbaceous plant biomass.
5. Soil moisture, temperature, and nitrate were the three main control variables of microbial denitrification in alluvial soils in decreasing order of importance.
6. The model developed for denitrification with interaction effects outperformed a pure additive model. Soil moisture was involved in all interactions, emphasizing its importance in predicting denitrification.
7. These results are discussed in the context of scenarios for future change in European hydrological regimes.

Cuvinte cheie: Zona ripariana, lunca raurilor, procese microbiene, Europa, schimbari climatice // riparian zone, river floodplain, microbial process, Europe, Climate change

URL: http://www.cesec.ro/pdf/Pinay%20et%20al[1].%20FWB.pdf