The germinable soil seed-store ofthe northern jarrah (Eucalyptus marginata Donn ex Sm.) forest was found to average 767 seeds m~( range:377-1579 seeds m^-) over six randomly selected plots within a range of forest sites. .A total of 68 different iaxa of vascular plants were recognized following heating and glasshouse tray germination tests of field-collected soils. Both the qualitative and quantitative composiiion of the soil seed-bank were dominated by annuals and sub-shrubs. Because less than 10% ofthe seed ofthe soil was from species ofthe dominani iree and woody shrub strata, there were major floristic differences between the existing flora and the composition of the soil seed-bank. The influences ofthe soil seed-bank on rehabilitation of disturbed jarrah forest lands and current fire management are discussed.

Dormant seeds of 18 species from 9 families covering a diverse range of seed dormancy syndromes and life histories from the southwest Australian biodiversity hotspot were assessed for germinability following storage at 15–25°C for 36 months. A total of 10 species with physical dormancy (PY) and 8 with either physiological dormancy (PD) or morphophysiological dormancy (MPD) were assessed as part of the study. Prior to storage, germination from dormant seeds was 1–27%, rising to 41–100% following specific dormancy‐breaking treatments. When seed dormancy was removed prior to storage for 36 months seeds from all species were found to maintain a nondormant state and germinate to a similar level to that observed at the beginning of the experiment (44–100%). Likewise, seeds that did not receive a prestorage dormancy‐breaking treatment maintained a dormant state (0–50% germination) and subsequently responded well to a dormancy‐breaking treatment immediately prior to germination assessment (49–99%). There were minimal differences in response to dormancy‐breaking treatments before and after 36 months storage (average 4–6% difference) and in the germination responses observed between both storage environments assessed (15°C/15% eRH or 15–25°C air dried). Based on these findings, storing seeds in a nondormant state does not alter germinability and this approach provides significant benefits to current seed‐based restoration programs through reduction of double handling and improved seed use efficiency.

Glasshouse trials in trays of soil measured the germination response to high temperatures and the presence of charcoal in 40 non-leguminous understorey species of the northern jarrah (Eucalyptus marginata Donn ex Smith) forest. Species producing relatively low proportions of viable and germinable seeds tended to be the long-lived resprouting species where reproductive output may not be of major adaptive significance. Three species, Conostylis setosa, Trymalium ledifolium and T. spathulaturn, with seed stored in the soil, were stimulated to germinate by high temperatures. Bradysporous, obligate reseeding species showed either no temperature effect (mainly species of Dryandra) or death at high temperatures (species of Hakea, whose seeds normally are protected by woody fruits). Charred wood of Eucalyptus marginata induced an increase in the proportion of Burchardia umbellata germinating under the test conditions. Relationships of the seed germination results to aspects of r- and K- selection theory and fire management policy in the northern jarrah forest are also discussed.

No abstract

This study used field lysimeters to investigate the reduction in the leaching of phosphorus (P) applied as superphosphate fertilizer from a very sandy Swan Coastal Plain soil treated with bauxite processing residue (red mud) neutralized with either waste gypsum from the phosphate industry or ferrous sulfate (copperas) from the titanium dioxide industry. Addition of 500 t ha-' red mud/gypsum or 200 t hap1 red mud/copperas were found to reduce the leaching of P to below 3 kg ha-l for application rates of 270 and 80 kgP ha-1, respectively. Water retention from these excessively well drained soils was increased by 14 and 50% by the addition of 200 and 2000 t ha-l red mud, respectively. The pH of the leachate for all rates of red mud/copperas application increased from approximately 4 to range between 7 and 7-5. The concentrations of Na and SO4 were about 8 and 17 g1-l, respectively, in the initial leachates collected from the 2000 t ha-' red mud treatment but declined to approximately 0.4 and 2.0g l-1 after 3 years of leaching. The Ca leaching appeared to be initially controlled by the solubility of the excess CaSO4 remaining after red mud neutralization, with concentrations ranging between 0.3 and 0.5 g l-1 before declining to approximately the levels for untreated soils of 0.01-0.06g l-1. The Na, So4 and Ca concentrations in the leachates from the 500 t ha-l red mud/copperas treated soil decreased to acceptable levels after 2 years. High total soluble salt (TSS) levels associated with high levels of residue application may affect pasture production in the years immediately following soil amendment