Each year, several hundred hectares of land is restored following mining in the Northern Jarrah Forest in south-west Western Australia. The aim of the restoration program is to recreate a self-sustaining Jarrah Forest ecosystem that requires no additional management practices to adjacent unmined forest. Given that all biological material (i.e. vegetation and topsoil) is removed prior to mining, plant return is almost exclusively through translocation, where plants and seeds are transferred from an ex-situ collection or natural population to a new location.
The sources of plants for program are: the soil seedbank within fresh and stockpiled topsoil; seeds collected from the surrounding forest and stored under ex situ conditions until seeding; and plants propagated from seeds, cuttings or tissue culture. Seed and plant traits dictate the method of plant return, with additional drivers such as material availability, cost effectiveness and establishment success also considered. The topsoil seedbank contains persistent, geosporous seeds. Serotinous (canopy stored) species and additional geosporous species are seeded. Species that are clonal, or do not produce many seeds are propagated in nurseries and planted. Seeds of forty species and tubestock of fifteen species of plants are used, supplementing >100 species replaced through topsoil.
Plant species richness and density is monitored and compared with restoration targets (completion criteria), informing adjustments to future seeding and planting rates. Experiments to improve success have included fertiliser treatments, pot types, propagation methods, companion planting and plant guards. This adaptive management approach has been ongoing since restoration using endemic flora began in 1988.