IVL Swedish Environmental Research Institute

The long-term effects (27-36 years) of conventional and whole-tree harvest on soil water chemistry (50 cm depth) have been examined at three coniferous sites. One of the most important findings of our study were that WTH caused a long-term (27-30 years), but temporary loss, of exchangeable Ca2+ measured as lower soil water concentrations at 50 cm depth as a result of large amounts of Ca2+ being removed during harvest. In addition, WTH resulted in lower soil water pH and ANC. Treatment effects were also noted for SO42- which could be the combined results of lower dry deposition in WTH-plots and/or increased retention in the mineral soil. The main treatment differences are temporary and had disappeared during the second study period between 2008 and 2010 (i.e. 32 to 35 years after harvest). These results are in agreement with previous soil studies carried out at the same sites. The implications of WTH effect are discussed in the context of validating model forecasts and need for ash-recycling.

The long-term effects (27-36 years) of conventional and whole-tree harvest on soil water chemistry (50 cm depth) have been examined at three coniferous sites. One of the most important findings of our study were that WTH caused a long-term (27-30 years), but temporary loss, of exchangeable Ca2+ measured as lower soil water concentrations at 50 cm depth as a result of large amounts of Ca2+ being removed during harvest. In addition, WTH resulted in lower soil water pH and ANC. Treatment effects were also noted for SO42- which could be the combined results of lower dry deposition in WTH-plots and/or increased retention in the mineral soil. The main treatment differences are temporary and had disappeared during the second study period between 2008 and 2010 (i.e. 32 to 35 years after harvest). These results are in agreement with previous soil studies carried out at the same sites. The implications of WTH effect are discussed in the context of validating model forecasts and need for ash-recycling.