Soil temperature and water content dynamics after disc trenching a sub-xeric Scots pine clearcut in central Sweden

Abstract Soil scarification is widely used in boreal forestry to promote the growth and survival of seedlings. The aim of the study was to describe and analyze the impact of disc trenching on soil temperature and water content dynamics during the first six growing seasons after clearcutting. The site is a sub-xeric, coarse textured, coniferous field experiment, near Hagfors, central Sweden. Soil temperature and water content were measured hourly both 20 and 45 cm below the original surface of the mineral soil in three types of microsites created by disc trenching (furrows, ridges, and between-furrow areas) and an undisturbed control microsite outside the disc-trenched area. Pinus sylvestris L. seedlings were planted in the furrows and the control area before the measurements. The soil temperature and water content data were analyzed using linear mixed-effect models. Numbers of days exceeding critical thresholds of soil temperature and water content for seedling growth at each microsite were also calculated. Disc trenching increased soil temperature in the topsoil ( 3 /m 3 ) was 423 in the furrows compared to 554 in the control area. None of the microsites was wet enough to hamper aeration of roots in the topsoil. In conclusion, soil temperature and water regimes were more favorable for the seedlings in the furrows than in the control area for at least six growing seasons. We recommend planting soon after disc trenching to maximize benefits from the improved soil temperature conditions in the furrows.