The dirt on assessing post-fire erosion in the Mount Lofty Ranges: comparing methods

Abstract

Land managers are required to assess a range of environmental attributes prior to and after prescribed burning. Current environmental assessments vary depending on the organisation involved and the existing information about localised soil erosion. Auditing successful environmental assessments requires ongoing field monitoring to evaluate whether the magnitude and extent of predicted post-fire impacts are comparable. The impacts of post-fire erosion were assessed by the authors using the techniques of water sampling, sediment traps, erosion pins, laser scanning, photogrammetry and visual field assessment. Each data collecting method varies in its spatial and temporal reach in terms of monitoring landscape changes in a post-fire environment. The methods also vary in cost, time and technical complexity. This paper uses a case study of the Mount Lofty Ranges, South Australia to apply and assess post-fire erosion field techniques in relation to a wildfire at Mount Bold, a Holocene paleofire located at Cleland and ten prescribed burns conducted within the Mount Lofty Ranges. The techniques are assessed for their merits in the context of simplicity for land management staff to use and associated costs. They are further examined in light of their application to different timeframes, spatial scales, magnitude and frequency. Our investigation leads to the recommendation of a simple framework for quick and relatively easy assessment, which is cost effective and can be carried out by both researchers and land management agencies.