Peatland has low litter decomposition rate because of low temperature, oligotrophic, and acidic soil. Climate warming and increase of nitrogen deposition are predicted to accelerate soil respiration and change carbon cycling in this kind of ecosystems.

Furthermore, plant biomass and species composition is predicted to change as a result of climate warming and soil nutrient enrichment. Change of litter quality may accelerate the change of carbon cycling.These changes may bring succession into forest and declination of plant diversity of peatland ecosystem.

We measured plant biomass and litter decomposition rate at 15 peatlands located around Mt,Hakkoda,Aomori,Japan, which have various environmental condition and plant composition. We aimed to know the determinant of litter decomposition rate. First, we put litter of plant which predominant at each peatland. We estimate carbon release from study site based on plant litter production at each peatland and compare decomposition rate among species. Second we measured litter decomposition rate of same species and place to elucidate the contribution of environmental condition. Third we compare carbon balance of plant growth and litter decomposition among these peatlands.