Soil development, plant colonization and landscape function analysis for disturbed lands under natural and assisted rehabilitation

[Truncated abstract] Spontaneous plant growth and soil development occur at disturbed sites with their extent and nature being variously affected by soil fertility status, local climate and topographic conditions. Soil-plant interactions can be diverse and site-specific within a disturbed landscape. The main purpose of the present study is to evaluate soil characteristics and landscape indices in relation to natural plant growth and soil development under different conditions and for diverse materials. A comprehensive study has been carried out to evaluate spontaneous soil development and plant colonization on various regolith materials at a railway cutting near Jarrahdale bauxite mine and on various substrates comprising waste rock, weathered regolith and replaced topsoil at Scotia (Norseman, Western Australia) and Kelian (East Kalimantan, Indonesia). At Jarrahdale soil development has occurred slowly over 36 years in relation to morphological changes in surface horizons. Soils at several locations exhibit substantial changes in color, texture and structure. The slow soil development is primarily due to low biomass and litter contributions (˜1 Mg/ha) from colonizing plants (e.g. Dryandra sessilis, Eucalyptus marginata and low shrubs) on the cutting shelf and slow litter decomposition.