We explore the environmental effects on variation in floristic compositional among montane shrub-dominated wetlands at the edge of their geographic distribution within the New England Batholith of eastern Australia. Canonical Correspondence and Redundancy Analyses revealed patterns and gradients in vascular plant species and families of bog communities. Variance partitioning quantified the relative contributions to variation in: (1) species composition; and (2) family composition due to climate, space, and landscape variables. Eleven of the 55 explanatory variables explained 29.2% of the total variance in the species dataset. Climatic factors were overall the best explanatory variables followed by spatial and then landscape characteristics. We found that climate variables were of most importance in determining whether shrub-dominated wetlands will occur at all and also their composition, which is in contrast to results from other studies not conducted at the edge of community distribution. Climate variables associated with seasonality were found to be highly significant correlates of composition as has been found for montane shrub-dominated wetlands in other parts of Australia. The season in which moisture availability becomes critical varies across different rainfall climatic zones. Under current predicated changes in regional climate, it is likely that an increase in variability and seasonality of climate will cause a retraction in the distribution of Australian montane bogs.

The floristic composition and vegetation partitioning of the ephemeral wetlands of the Pilliga Outwash within the Pilliga National Park and Pilliga State Conservation Area (30˚30'S, 149˚22'E) on the North Western Plains of New South Wales are described. SPOT5 imagery was used to map 340 wetlands across the Pilliga Out wash. A total of 240 plots within 31 wetlands explored composition and species richness in relation to water depth and wetland size. The predominant community described is the species-rich herb field of shallow basin wetlands, along with the structurally distinct but the less common sedge land/herb field of the deeper 'tank' wetlands and a single wetland with a floristically depauperate 'Diplachne fusca' wet grassland. A total of 131 taxa were recorded including three species listed under the NSW Threatened Species Conservation Act (1995): 'Eriocaulon australasicum', 'Lepidium monoplocoides' and 'Myriophyllum implicatum'. New records for an additional six taxa were recorded for the North Western Plains. 11% of taxa were exotic in origin.

We present a new well dated Holocene record of environmental change from Little Llangothlin Lagoon in eastern Australia derived from aquatic plant macrofossils, macroscopic charcoal flux, and sediment stratigraphy from multiple cores. Little Llangothlin was an ephemeral freshwater wetland exhibiting frequent dry phases between 9800 and 9300 calendar years before present (cal. yr BP). There was a switch to a more positive water balance after 9300 cal. yr BP, and by 8000 cal. yr BP, there was a lake that persisted until 6100 cal. yr BP. The period between 6100 and 1000 cal. yr BP was much drier, and there is no evidence for a permanent lake during this period. The Little Llangothlin record provides evidence for a wet phase during the Early to Middle Holocene (9000-6000 cal. yr BP) from the boundary region between temperate and tropical influences in eastern Australia. We propose that generally enhanced circulation after 9000 cal. yr BP explains the pattern of increasing moisture at the site at this time. The later Holocene climate at the site is consistent with other sites in south east Australia with a switch to generally drier conditions after 6000 cal. yr BP.