Effects of soil water potential on germination of co-dominant Brigalow species: Implications for rehabilitation of water-limited ecosystems in the Brigalow Belt bioregion

While E. cambadgeana demonstrated the fastest and most prolific germination across the widest range of water conditions with germination being observed even at water potentials as low as −1500 kPa, E. populnea and C. cristata required wetter conditions over longer periods to achieve maximum germination rates. For the 11 years of meteorological data examined in this study, soil water conditions were most favourable for germination of E. cambadgeana; this was primarily due to its high tolerance of water deficit in soils of lighter texture than that of the denser Black Vertosols. In contrast, for the seed-soil combination of C. cristata and Black Vertosol, modelled climatic conditions proved favourable to triggering germination only 25% of the time. The empirical data on seed germination can be used to parameterise and calibrate germination models.