Short rotation coppices (SRC), which usually consist of densely planted and high-yielding willow and poplar clones, can provide a sustainable source of energy. Furthermore, the potential of these systems as carbon sinks, recognized in the international debate on the global carbon balance and climate change impacts, may also make them a good option for many countries to receive ‘carbon credits’ to offset the effects of greenhouse gases emissions.
As part of a research project and with the purpose of evaluating and optimizing the contribution of this type of intensively managed crop in carbon sequestration, CO2 vertical fluxes have been measured in a SRC stand installed in Bragança, Portugal. Chamber based-techniques were designed to measure both CO2 soil effluxes and exchange rates between the crop canopy and the atmospheric boundary layer. Soil fluxes are measured at various locations by means of an open top dynamic chamber. Biosphere/atmosphere CO2 exchange rates are evaluated by using a large ventilated open top chamber. CO2 analyses are performed by using an ADC 2250 differential infrared gas analyzer coupled to an automatic sampling and acquisition system. Measurements are taken every 10 seconds and averaged over half hour intervals. These measurements will be continued throughout several seasons, with the purpose of investigating daily and seasonal patterns of net ecosystem CO2 exchange rate. To support our analysis, other relevant environmental variables as meteorological, soil temperature and soil humidity have also been monitored.
The results obtained so far are still scarce, but very encouraging since they show the ability of the system to perform reliable and continuous measurements of CO2 fluxes.
This presentation will focus on the methodologies and on the evaluation of the magnitude of these production systems as carbon pools, in order to contribute to a better description of the current carbon fluxes pools
