The project will improve our understanding of the processes of plant growth and decomposition of plant residues in peatland ecosystems. The main objective is to determine the influence of nitrogen (N) deposition on the carbon balance in nutrient poor peat bogs.
This objective will be achieved by a multidisciplinary approach combining expertise in plant science, microbiology of soil and plant residues and peat chemistry. The effects of different forms and rates of inorganic (N) on different moss species will be studied in glasshouse experiments in Switzerland using newly developed techniques for growing Sphagnum mosses. Information already obtained in this way will be used to set up field experiments on nutrient poor bogs in Finland, France and Scotland, which represent the widest latitude range of climatic conditions favouring oligotrophic peat development in Western Europe. Atmospheric N deposition which ranges from 2 in Finland to 22 kg N/ha/yr in S.E. France will be measured at each site. Different parts of the problem will be studied at each site and hydrological, ecological and climatic measurements made at all three field experiments. In Finland, the emphasis will be on the response of peat-forming mosses to N additions and the competition between species for N. Work in France will concentrate on measuring the balance between primary production of plants and the decomposition of peat and plant residues in different horizons of the bog. The fate and movement of the nitrogen in the peat will be studied in the UK using 15N labelling techniques.
The results from each research group will be integrated into a mathematical model of peat accumulation which will link the C and N cycles in peatland ecosystems. This will provide a basis for predicting the long term effects of N on oligotrophic peat and also improve the scientific foundation for the application of a critical load concept to atmospheric nitrogen deposition to peatlands. The information obtained will make a contribution to ways of restoring the growth of peat forming vegetation on areas cutover for fuel on horticultural production. The temperature range and the different hydrological conditions at field sites and in glasshouse experiments will enable the model to predict the effects of changes in climate.
Funding SchemeCSC - Cost-sharing contracts
63970 Rouillas-bas, Aydat