What are the chances of successfully replacing buffel grass with native plant communities in central Queensland's coal mine rehabilitation sites?

摘要

It is sometimes desired to establish native plant species on rehabilitated minesites of central Queensland that are occupied by exotic pasture grasses such as Cenchrus ciliaris, which is more effective than native plant species in utilising the limited available soil moisture. Investigations were conducted on the hydrological characteristics of the mine site soils and on the water requirement for germination of selected native species. Rainfall simulation experiments using established pastures of different ages showed that pastures increased the infiltration rates and water retention capacities of soils as compared with bare surfaces. Germination experiments exposed non-dormant seeds of six native tree and shrub species and five grass species to decreasing osmotic water potentials (OWPs). Each species varied in its rates of imbibition, radicle elongation and germination, as well as their tolerance to dehydration during germination. Imbibing seeds of all species would germinate only if they reachedcritical minimum water contents, regardless of the OWPs imposed during imbibition.Coupled with the knowledge on the rainfall characteristics of the region, this study demonstrates the possibility of increasing the success of native species establishment on rehabilitated minesites in central Queensland by identifying environmental conditions that must be provided in order to achieve successful germination.