In order to evaluate the modifications of some chemical properties of the water of La Grande 2 reservoir after flooding, experiments were done on spruce and pine undergrowth soil, on peat bog and on spruce and pine tree. The influence of continuously aerated water was first tested; then, after oxygen consumption, the same sample was used to evaluate the changes occurring under anoxic conditions. The results indicate that at the beginning of flooding in oxygen saturated water or at the beginning of anaerobic conditions, a rapid increase in conductivity, colour, tanins, potassium and calcium occurs. These variations diminish rapidly after a few days. Generally, the release of biogenic substances is higher during continuous aeration than in anaerobic conditions. The contribution of trees to these changes is much more important than their respective undergrowth soils.
展开▼
