Performance of Copper and Non-Copper Based Wood Preservatives in Terrestrial Microcosms

Abstract

Summary The use of wood preservatives based on copper, chromium and arsenic (CCA) has become restricted in several countries due to environmental concerns. As a consequence, several chromium and arsenic free preservatives based on fungicides, regarded as more environmentally acceptable, have been developed. Most of these preservatives have only been tested in the laboratory against pure cultures of basidiomycetes and their long term effectiveness in practice is in many cases unknown. The effectiveness of six different preservatives, representing different types and combinations of fungicides, against mixed natural populations of micro-organisms, was evaluated during one year in terrestrial microcosms with soils known to provide high activity of different types of wood destroying micro-organisms. Of the fungicides tested, copper compounds provided the best protection against wood destroying micro-organisms. Copper free preservatives provided good protection against pure cultures of brown- and white rot fungi, but were ineffective when treated stakes were exposed in unsterile soils.