The Effect on vegetation and soil temperature of logging flood-plain white spruce /

Abstract

During winter 1982-83, five silvicultural treatments were applied to white spruce (Picea glauca) stands on Willow Island, near Fairbanks, Alaska. The treatments were 2 shelterwood fellings with residual tree spacing of 9 or 14 m, clear felling, clear felling followed by broadcast burning of slash and a thinning; control plots were not treated. The effect of these treatments on vegetation, soil temperature and frost depth were studied during 1983-85. Brief descriptions are given of 13 vegetation units (plant communities) on the island. Clear felling followed by burning caused the most marked changes in vegetation and soil temperature; post-disturbance vegetation was dominated by invading and deep-rooted species. Soil temperature at 10 cm depth was almost twice as high on the burned plot in comparison with the control and all frost had left the soil. Clear felling without burning had less effect on the site and many understorey species survived logging. Shelterwood fellings had little effect on vegetation, but both this treatment and clear felling alone caused significant increases in soil temperature. Soil temperatures increased only slightly after thinning.