Successful recruitment following translocation of a threatened terrestrial orchid (Diuris tricolor) into mining rehabilitation in the Hunter Valley of NSW

摘要

Translocation of threatened terrestrial orchids is increasingly seen as a viable ameliorative conservation option when habitat is destroyed or modified through changing land use. Most orchid translocations reported in the literature detail nursery-raised seedlings planted into intact and suitable habitat, and few involve translocation of entire plants and their mycorrhizal fungal associates. As part of a larger translocation study, soil cores containing 46 individuals of the threatened Painted Diuris (Diuris tricolor) were translocated into herbivore-proof plots on restored and rehabilitated post-mining lands in the Hunter Valley of New South Wales. After 3 years of annual flowering and fruiting, new recruits (mature flowering plants) were observed within translocation plots but outside of original soil cores, and at 6 years following translocation 29 new individuals were observed. Two of these individuals germinated outside of fenced plots. At peak flowering in 2020, a search of rehabilitated lands outside of translocation plots failed to locate any orchids, discounting the unlikely possibility that orchid tubers may have survived the process of topsoil stockpiling and respreading. Successful recruitment of Painted Diuris into mining rehabilitation has the potential to significantly offset any losses of this species resulting from mining operations within the region.