Tussock and sod tussock grasslands of the New England Tablelands Bioregion of eastern Australia

Abstract

We surveyed temperate montane natural grasslands across the New England Tablelands Bioregion (NETB) and assessed the phytosociology, occurrence and threats to these assemblages. In total, 123 full floristic survey plots were placed within natural grasslands across the NETB. Mapping was undertaken within a subset of the NETB using ADS40 imagery. Analysis of the floristic data was performed using the Kulzynski association measure and UPGMA fusion strategy. Canonical correspondence analysis was performed with species data in association with 42 environmental variables. An estimated 25 000 ha of native tussock and sod tussock grasslands within six floristic assemblages were found within the NETB. The maximum extent of predicted high-quality stands may only be 2500 ha with most occurrences degraded and threatened by agricultural practices, exotic species and changes in above- and below-ground water resources. Native taxa were significantly associated with altitude, rock type and differential temperature tolerances. Altitude, eastness (longitude) and radiation of the wettest period were significant drivers of exotic species occurrence.