AbstractBlock fields and block streams above 1000 m on Mt Wombargo and Mt William, in northeastern and western Victoria respectively, were found to be in various stages of colonization. Plant succession was influenced by slope, altitude, precipitation, fire and the nature of the boulder accumulation. Lichen colonization was abundant on exposed surfaces. Soil build up, which commenced at deeper levels amongst the boulders, was hastened by the development of moss mats, and in particular by the accumulation of litter from adjacent eucalypt forest and woodland.