Effect of trampling on the soils of the St James Walkway, New Zealand

Abstract. The influence of trampling on the soils of the St James Walkway was studied during 1985 by comparing ‘on’‐ and off‐track sites. Trampling increased the average soil bulk density by 0.3 g/cm 3 at 0–5 cm depth and by 0.1 g/cm 3 at 10–15 cm depth. Trampling increased the average soil shear strength by 11 kPa at 0–5 cm depth and by 6 kPa at 5–10 cm depth. All mineral soils were compacted to some extent by trampling. The podzolized high country yellow‐brown earths (Dystrochrepts) were the most affected because their organic topsoil was truncated. Their exposed subsoil was however more resistant to further damage than their topsoil. Organic soils (Medihemists) were not compacted but their very low shear strength and high moisture content make them unsuitable for tracks. Untrampled soil bulk density and soil stone content were negatively correlated with the change in bulk density by trampling, and could be used to predict the risk of soil compaction by trampling.