This study assessed the short-term effects on non-target soil invertebrates of leachates from a naturally durable hardwood and timber treated with two copper-based wood preservatives. Natural rainwater leachates from kwila decking, and radiata pine-decking treated with CCA or copper-azole, were collected and applied on mown lawn soil in Brisbane, Queensland. The soil study consisted of 5 treatments: an independent control (replicates untreated), wet control (replicates treated with rainwater only), CCA, copper azole and kwila-extractive leachates. Two applications of each treatment were made. Soil samples were collected before application and then twice after the first application (3 and12 days) and 3 times after the second (3, 8 and 12 days). Soil arthropods were extracted from soil cores using Tullgren funnels. Frequency analysis and multivariate techniques were used to analyse the data for treatment effects. Soil invertebrates were dominated by mites (84%), which were identified to family level. We did not detect any difference in the density of mites except in the kwila-extractive leachate, where mite density increased significantly. However, there were detectable differences in mite community structure between all treatments, indicating differential effects of the treatments on the soil arthropod community.

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