| title: | The role of bog pool bottom erosion on the acceleration of peat decomposition, development of pools and carbon balance of mires |
|---|---|
| reg no: | ETF6755 |
| project type: | Estonian Science Foundation research grant |
| subject: |
1.14. Ecology |
| status: | accepted |
| institution: | TU Faculty of Biology and Geography |
| head of project: | Edgar Karofeld |
| duration: | 01.01.2006 - 31.12.2008 |
| description: | The mires of the boreal zone with the largest predicted temperature increases contain 120-450 Gt of carbon as peat. Therefore, changes in the balance between carbon fixation, storage and release may change fundamentally the global greenhouse gas budget. Increased temperatures in the main part of peat deposit – the catotelm – may cause acceleration of peat decomposition, which is usually very slow and stable. When temperatures at the bottom of bog pools increase to 15 degrees the decomposition processes and the release of methane increase sharply. Increased gas volume will decrease peat density leading to increased buoyancy. Should peat elasticity be exceeded, peat masses will rise from the pool bottom to the surface water layers, where – due to the much higher temperatures compared to the pool bottom – peat mineralization and release of decomposition gases will increase significantly. This process may play an important role in pool development and in the carbon balance of mires. The main aims of the study are: • To elucidate the spatio-temporal dynamics of pool bottom rise and descent in relation with pool parameters, water temperature and peat type in pool bottom, • To reveal with field and laboratory experiments which role the presumed acceleration of peat decomposition caused by pool bottom rise may have in pools, • To quantify the carbon loss from raised pool bottoms and peat blocks, and • To understand the role of these processes in pool deepening and their development. We hypothesise that predicted temperature rises will cause the uplifting of pool bottoms to become even more common and last for longer periods. Therefore, decomposition of peat uplifted from cooler bottom to warmer surface layers will accelerate causing increased emissions of carbon gases (especially methane) and changes to bog carbon balance. |
| project group | ||||
|---|---|---|---|---|
| no | name | institution | position | |
| 1. | Edgar Karofeld | Tartu Ülikool | ||
| 2. | Robert Szava-Kovats | |||