Three experimental forest drainage sites were established in Alberta’s boreal forest to determine the effects of lowered water tables on soils, local hydrology, ground vegetation composition and tree growth. The sites were established in 1985 and ditched using from 30- to 60-m ditch spacings in 1986-87, as part of the Canada-Alberta Forest Resource Development Agreement (FRDA): Wetland Drainage and Improvement for Forestry Program (Phase 1). Data were collected before (from 1985 to ditching) and after ditching from instrumented transects and permanent sample plots established on drained and undisturbed control areas. Preliminary results from some of the component studies were published in 1990.
Funding for continuation of the project (Phase 2) was approved in 1992 as part of the Canada-Alberta Partnership Agreement in Forestry (PAIF). The primary objectives of this phase were to evaluate the growth of commercial tree species on drained forested peatlands and to determine the effects of water table management on ground vegetation composition. These objectives required that previously established permanent sample plots be remeasured periodically. This report provides results from a number of component studies including those on water table drawdown, substrate water content, peat subsidence, ground vegetation composition changes, the effects of ditching, thinning and fertilization on black spruce growth, and the survival and growth of tree seedlings on a ditch-mounded site.