The effects of recent land use changes on red podzolic soils near Sydney, N.S.W., Australia

Abstract

Summary The effects of changing land use on morphological, physical and chemical properties of red podzolic soils under pasture and forest are reported from four soil catenas north west of Sydney. The results indicate that the pasture soils have lower organic matter contents and porosities, higher bulk densities and reduced aggregate stability in the A horizons compared with their forest counterparts. Biological homogenisation (bioturbation) is particularly more marked in the forest topsoils compared with the pasture soils. The changes in soil properties can probably be attributed to differences in soil fauna and rates of faunal activity under the different vegetation types. Microclimatic differences may also influence faunal activity between the sites. The decrease in bioturbation and structural stability under pasture have apparently led to a slight increase in clay translocation from A to B horizons and the development of a clearer texture contrast. No major evidence or erosion of topsoils on convex sites nor downslope accumulation of eroded material was recorded.