PEATmod · PEATland modelling for global carbon cycle and climate models

PEATland modelling for global carbon cycle and climate models

Peatlands are present in humid regions. In these ecosystems, water remains close to the surface and stagnates or flows very slowly. In peatlands, vegetation stores carbon through photosynthesis while the waterlogged conditions prevent this carbon to naturally decompose. This results in an accumulation of carbon and thus in peat growth. However, peatlands are also emit carbon, in form of methane and CO2 from respiration (Figure 1). Since their development, the imbalance between carbon storage and release has allowed these ecosystems to accumulate large amounts of carbon. It is estimated that they contain 530-694 Gt of carbon, i.e. almost as much as the total amount of carbon in the atmosphere. Changes in climate and atmospheric CO2 concentration affect photosynthesis, respiration and methane production in different ways and at different magnitudes. The effect of these changes in peatlands remains debated and there is a risk that peatlands could turn into net carbon sources, thus increasing the CO2 concentration of the atmosphere. Considering the amount of carbon that they store, it is important to assess whether large carbon quantities will be released or if carbon storage will be enhanced in the future. A better insight into this question can be gained from studying the feedback processes between peatlands, the atmosphere and hydrology. Current knowledge on peatlands dynamics allows to adequately represent carbon exchanges in peatlands, especially for peatlands at high latitudes. This knowledge has been used to develop peatland modules in some of the existing global vegetation models in order to assess the role of peatlands at global scale. Although some models already include carbon functions and mechanisms in peatlands, the feedbacks between hydrology, vegetation and carbon are missing from most models, and this limits the accurate representation of the impact of peatlands on the atmosphere and the global carbon cycle. The aim of the project was to take the firsts steps to include the necessary feedback mechanisms into the peatland modules in global vegetation models. We chose to focus on low-latitude peatlands, in order to integrate these important ecosystems into models. Although peatlands are present at all latitudes, their properties change depending on the local topographical, climatic and geological conditions. To be able to represent peatlands in global models, the processes driving their functioning and resilience need to be identified. The approach followed during the project included a wide range of peatland experts from different regions of the world. The results showed that low-latitude peatlands should be considered separately from high-latitude peatlands for modelling purposes. Key areas where research is needed were identified. The first steps toward the inclusion of low-latitude peatlands in global vegetation models were performed. In conclusion, the project brought expertise in peatland modelling back to Europe and enabled to strengthen the links between the peatland science communities in North America, South America, Asia and Europe.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз