Soil conservation in a forested mountain catchment

In 1982 – 2015, environmental impacts of commercial forestry practices were studied in the Jizerka experimental catchment (the Jizera Mountains, Czech Republic). Skidding the timber by wheelled tractors caused 10.3 km-1 of skid trails and the drainage density increased from 1.45 to 7.55 km-1. On the harvested runoff plots, not affected by skid trails, the loss of soil 0.007 - 0.014 mm year-1 was comparable with undisturbed forests. But, the eroded soil in skid trails reached 6.17 mm (61.73 m3 ha-1) by harvesting 23,882 m3 of timber (i.e. 0.25 m3 per 1 m3 of harvested timber). At the catchment outlet, sediment yield reached 25% of the soil eroded. Natural regeneration of erosion rills was supported particularly by the development of herbaceous vegetation. In 2003, twelve years after the logging, only 1.5 km (15 %) of active deeper rillswere still identified