Recovery of soil physical properties from compaction and soil profile disturbance caused by logging of native forest in Victorian Central Highlands, Australia

Abstract

Soil profile disturbance and compaction can have a long-term detrimental impact on soil properties. Organic matter, macroporosity and bulk density was measured during 1989 and 1999 in three types of snig tracks: primary (PST), secondary (SST) and tertiary snig tracks (TST), log landings (LL), general logging areas (disturbed areas which were not occupied by snig tracks or log landings) and undisturbed areas (HA-S0). Within the general logging areas, measurements were made for three levels of soil profile disturbance: litter disturbed (HA-S1), topsoil disturbed (HA-S2) and subsoil disturbed (HA-S3). During 1989 samples were taken from 0 to 100 mm soil depth and during 1999 from 0 to 100, 100 to 200 and 200 to 300 mm soil depth. No significant differences in organic matter content, macroporosity and bulk density were found between 1989 and 1999 for most of the sampling sites. The rate of recovery of organic matter, macroporosity and bulk density varied depending with degree of soil disturbance and soil depth. The subsoil disturbance (HA-S3) had more influence on soil physical properties than any other type of disturbance. In general, the effect of soil profile disturbance and compaction on soil properties was greater at surface soil than deeper soil. Ten years after logging, macroporosity and organic matter content was significantly lower in the PST and HA-S3 compared to undisturbed areas. In the HA-S3 and PST, organic matter, macroporosity and bulk density was 31–41% lower, 44–60% lower, 22–68% greater, respectively, compared to undisturbed areas. The results are discussed in relation to tree growth and Montreal Process soil indicators.