Effect of heat treatment of forest soil on germination of buried seed

Abstract

Treatment of forest soils from south-eastern Australia with aerated steam within the range 5°C (5 min) to 71°(30 min) often increased the number and variety of buried seed which germinated compared with seed germination in untreated soil. At the lower temperature (55°) prominent germination occurred in species of Juncaceae and Cyperaceae, Poranthera microphylla, Oxalis corniculata and some grasses. At higher temperatures, legumes, some epacrids and species of genera such as Pomaderris, Spyridium, Dichondra, Geranium, Opevcularia and Poranthera germinated. Artificial exposure of surface open-forest soil to the sun in summer was sufficient to cause or increase germination of several species when the soil was subsequently moistened.