Initial Effects of Deforestation on Herbaceous Species Composition in Grassy Woodlands of the Northern Tablelands, NSW Australia

Initial Effects of Deforestation on Herbaceous Species Composition in Grassy Woodlands of the Northern Tablelands, NSW Australia

Limited information on the initial effects of clearing and thinning on herbaceous vegetation of grassy temperate eucalyptus forests exists. The aim of this investigation is to study the initial changes in species composition following clearing and thinning. A deforestation experiment was established where clearing, thinning of 50% of canopy cover and control treatments were established. In the open-forests, patterns in herbaceous species composition were strongly influenced by the presence of trees, with weeping wheat grass (Microlaena stipoides) dominant, whereas wiregrass (Aristida ramosa) dominated interspaces and canopy gaps. Immediately following clearing, significant changes in the herbaceous species composition were observed, with 26 new species recorded. The original vegetation pattern was lost, being replaced by Cyperaceae and Juncaceae, and a large number of invasive ruderal species. A state and transition model that describes the changes in composition is presented.