Wardle: Ecology and Distribution of Silver Beech in the Paringa District

The Paringa district is almost completely forested below timberline, with conifer /hardwood forests pre;-ailing in the northeast, and silver beech widely dominant in the southwest, especially at the higher altitudes. In a transitional zone, silver beech grows as scattered stands, isolated by distances up to 6 km. During heavy glaciation of the mountainous part of the district, silver beech may have survived near the present coast and beyond it on land exposed by a lowered sea level. Post-glacial spread from such refugia to the most inland valley heads would require a spreading rate averaging at least 700 m/century, and it is suggested that this was achieved by dispersal of seed on to freshly exposed mineral soils, where beech seedlings apparently can grow independently of mycorrhizal infection. From the nuclei thereby established there was, and still is, gradual invasion of surrounding vegetation. The post-glacial pollen record and the present distribution of silver beech both indicate a pattern of northeasterly spread.