Albertas Wetlands PDF Download

"In 1985, a wetland drainage and improvement for forestry program was instituted under the Canada-Alberta Forest Resource Development Agreement to determine the effects of drainage on tree growth, ground vegetation, soils, peat, and local hydrology. Three experimental areas were chosen and portions of each drained in 1986 and 1987. Data were collected from drained and undrained portions. Additional data were collected from a treed swamp near Fort McMurray that was subjected to different drainage treatments between 1975 and 1980. The intent, in this case, was to obtain an interim estimate of tree growth rates until sufficient time has elapsed to obtain estimates from permanent sample plots on the experimental areas. Results showed that the average depth to groundwater table after drainage was between 37 and 90 cm and varied with ditch spacing. The corresponding drops in water table levels were between 17 and 78 cm. The test areas with 30-m ditch spacings appeared to be overdrained. Stream water quality data from one site only have been interpreted so far. They show that drainage had little effect on measured physical and chemical stream water quality during low flows. Further analyses are required to determine the effects of drainage on peak flows. Initial results from the three experimental areas indicate that drainage has resulted in reduced ground vegetation cover (mosses, sedges and other herbs) and vigor. Lowering the water table on the swamp near Fort McMurray resulted in sigificant increases in height, diameter and volume of 30-year-old black spruce (Picea mariana). The increase in growth of black spruce was accompanied by an equally impressive growth of alder (Alnus crispa), willow (Salix spp.), birch (Betula pumila), aspen (Populus tremuloides) and balsam poplar (E. balsamifera)."--Page iii.