Potential for conservation and restoration following long-term pastoral use in a temperate forest-woodland-grassland mosaic on the Southern Tablelands, New South Wales

We document the transitioning of a 50 ha paddock from production grazing to conservation land use. Observations include: i) a quantitative ground layer vegetation baseline survey; ii) the species assemblage and iii) an estimate of the species dynamics in terms of colonization and local extinctions over a 15 year period. We interpreted site productivity to be the major factor influencing species composition, followed by moisture availability. The two vegetation types present, grassy woodland and sclerophyll forest, were floristically distinct but the lower slopes of the sclerophyll forest had a similar richness of native grassy ecosystem species to that of grassy woodland. The spontaneous colonization rate was one species per year (25% native, 75% exotic). Eradication efforts and spontaneous losses of species with small populations over the 15 years resulted in a net loss of one native and three exotic species. However, assisted colonization resulted in 17 local native species becoming naturalised. Our results demonstrate that significant native plant diversity (256 species, including 39 geophytes, 31 annuals and 187 other grassy ecosystem species) can persist under heavy livestock grazing if pasture improvement is limited. Moreover, the potential for introduction of additional species with active restoration is high. Conservation of grassland species would be better served if the significance of the grassy woodland-sclerophyll forest interface was recognized in conservation practice.