Rainforest invasion onto Tasmanian old-fields

Abstract

The regeneration of rainforest onto land cleared for grazing early this century was studied on several sites in northern Tasmania. Drimys lanceolata, a bird-dispersed species, was the main invader. The climax forest species. Nothofagus cunninghamii and Atherosperma moschatum were invading slowly from the forest edge with occasional trees established in the field. Woody plants in the old-field were clumped around logs. This was related to the role of logs in attracting seed and to possible roles as competition-free sites and sites safe from browsing and climatic stresses. Changes in dominance by particular life forms appeared to be related to dispersal events, environmental modification by the developing vegetation and life history characteristics. The extremely slow invasion by climax species is due to the absence of bare mineral soil as well as to dispersal characteristics, browsing and possibly exposure to climatic stresses.