title: Effects of brash removal after clear felling on soil and soil-solution chemistry and field-layer biomass in an experimental nitrogen gradient.
abstract: Biofuels, such as brash from forest fellings, have been proposed as an alternative energy source. Brash removal may affect the sustainability of forest production, e.g., through a change in the availability of cations and N in the soil. We report initial effects of brash removal on inorganic N content in humus and mineral soil, soil-solution chemistry, and field-layer biomass after clear felling an N-fertilisation experiment in central Sweden. The experiment comprised six different fertiliser levels, ranging from 0 to 600 kg N ha(-1). Urea was given every 5th year during 1967 to 1982 to replicated plots, giving total doses of 0 to 2400 kg N ha(-1). Clear felling took place in 1995, 13 years after the last fertilisation. The removal of brash decreased the NO3- content in the humus layer after clear felling. A decrease in the NO3- concentration of the soil solution was indicated during most of the study period as well. No effect of the previous N fertilisation was found in the humus layer, but in the mineral soil there was an increase in NO3- content for the highest N dose after clear felling ( p = 0.06). The soil-solution chemistry and the field-layer biomass showed an irregular pattern with no consistent effects of brash removal or previous fertilisation.
authors.affiliation: SkogForsk-The Forestry Research Institute of Sweden, Uppsala Science Park, Uppsala, Sweden. eva.ring@skogforsk.se
authors.forename: E
authors.initials: E
authors.lastname: Ring
authors.forename: L
authors.initials: L
authors.lastname: Högbom
authors.forename: H O
authors.initials: HO
authors.lastname: Nohrstedt
mesh_terms: D000383:Agriculture / Q000639:trends; D016573:Agrochemicals / Q000737:chemistry / Q000378:metabolism; D018533:Biomass; D002412:Cations / Q000737:chemistry / Q000378:metabolism; D004736:Energy-Generating Resources; D005308:Fertilizers / Q000032:analysis; D008903:Minerals / Q000737:chemistry / Q000378:metabolism; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism*; D017672:Nitrogen Compounds / Q000737:chemistry; D012107:Research Design; D012987:Soil / Q000032:analysis*; D012996:Solutions / Q000737:chemistry; D013548:Sweden; D014197:Trees / Q000254:growth & development / Q000378:metabolism
chemical_list: D016573:Agrochemicals; D002412:Cations; D005308:Fertilizers; D008903:Minerals; D017672:Nitrogen Compounds; D012987:Soil; D012996:Solutions; D009584:Nitrogen