title: Environmental impact assessment of wood ash utilization in forest road construction and maintenance--A field study.
abstract: The ever increasing use of wood material as fuel for green energy production requires innovative, environmentally safe strategies for recycling of the remaining wood ash. Utilizing wood ash in forest road construction and maintenance to improve mechanical stability has been suggested as a feasible recycling option. To investigate the environmental impact of wood ash application in forest road maintenance, a two-year field experiment was conducted at two Austrian forest sites (Kobernausserwald (KO) (soil pH 5.5) and Weyregg (WE) (pH 7.7)) differing in their soil chemical properties. Two different ashes, one produced by grate incineration (GA) and the other by fluidized bed incineration in a mixture with 15 vol% burnt lime (FBA), were incorporated in repeated road sections at a 15:85% (V/V) ash-to-soil rate. Leaching waters from the road body were collected and analyzed for 32 environmentally relevant parameters over two years. Upon termination of the experiment, sub-road soil samples were collected and analyzed for ash-related changes in soil chemistry. Even though a larger number of parameters was affected by the ash application at the alkaline site (WE), we observed the most pronounced initial increases of pH as well as Al, As, Fe, Mn, Ni, Co, Cu, Mo, and NO2(−) concentrations in leachates beneath GA-treated road bodies at Kobernausserwald due to the lower soil buffer capacity at this site. Despite the observed effects our results indicate that, when specific requirements are met (i.e. appropriate ash quality, sufficient soil buffer capacity below the road body, and single time-point ash incorporation within several decades), wood ash application in forest road construction is generally environmentally acceptable.
authors.affiliation: University of Natural Resources and Life Sciences, Department of Forest and Soil Science, Institute of Soil Research, Konrad-Lorenzstraße 24, A-3430 Tulln, Austria. Electronic address: eva.oburger@boku.ac.at.
authors.forename: Eva
authors.initials: E
authors.lastname: Oburger
authors.affiliation: University of Natural Resources and Life Sciences, Department of Forest and Soil Science, Institute of Soil Research, Konrad-Lorenzstraße 24, A-3430 Tulln, Austria.
authors.forename: Anna
authors.initials: A
authors.lastname: Jäger
authors.affiliation: University of Natural Resources and Life Sciences, Department of Forest and Soil Science, Institute of Soil Research, Konrad-Lorenzstraße 24, A-3430 Tulln, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Pasch
authors.affiliation: University of Natural Resources and Life Sciences, Department of Forest and Soil Science, Institute of Soil Research, Konrad-Lorenzstraße 24, A-3430 Tulln, Austria; Austrian Agency for Health and Food Safety, Institute for Plant Protection Products, Department for Environmental Behaviour and Integrative Pest Management, Spargelfeldstrasse 191, 1220 Vienna, Austria.
authors.forename: Alex
authors.initials: A
authors.lastname: Dellantonio
authors.affiliation: University of Natural Resources and Life Sciences, Department of Forest and Soil Science, Institute of Forest Engineering, Peter Jordan-Straße 82, A-1190 Vienna, Austria.
authors.forename: Karl
authors.initials: K
authors.lastname: Stampfer
authors.affiliation: University of Natural Resources and Life Sciences, Department of Forest and Soil Science, Institute of Soil Research, Konrad-Lorenzstraße 24, A-3430 Tulln, Austria.
authors.forename: Walter W
authors.initials: WW
authors.lastname: Wenzel
keywords: Contamination; Forest road construction; Heavy metals; Lysimeter; Recycling; Wood ash