Selected properties of the incipient soils developing on coal mining wastes, Bowen Basin, Australia

摘要

The limited amounts of available good quality, fully developed soil frequently constrain the success of rehabilitation works. Consequently, the minesoils that develop spontaneously on spoil materials and their transported erosion products in post-mining landscapes must be used as alternative growing media in achieving rehabilitation objectives. The minesoils developing on spoils derived from open cut coal mining in four Bowen Basin mines are defined and selected properties contrasted with those of local, fully-developed soils. These diverse materials reflect the variety of parent materials present and are developing in immature, geomorphologically active landscapes where they are undergoing substantial physical weathering and, in some places, chemical weathering associated with pyrite oxidation. Important physical limitations as growing media include elevated dispersivity, a high tendency towards crust formation and a very limited development of biologically based structure. Minesoil pH, salinity and sodicity range widely and are used to define twelve classes of materials that reflect their potential limitations as growing media and in substrate stability. Extremes are seen as common and major constraints to soil and ecosystem development. Profile development is largely limited to the surface 50 millimetres. For minesoils to develop eventually into soils in approximate equilibrium with contemporary environments and to provide the ecosystem goods and services necessary to support natural patterns of biodiversity, productivity and water quality, their long-term development pathways need to be better understood.