The Impact of Grazing Pressure in Clearfelled, Burned and Undisturbed Eucalypt Forest

An area of dry eucalypt forest on dolerite in southeastern Tasmania with comparable sites that were a) unlogged, b) clearfelled, c) clearfelled and slash-burned, was monitored over a 24 month period. Detailed records were made of plant species composition and cover on floristically similar fenced and unfenced permanent plots in two major vegetation types. Mammal faecal pellets were cleared from each of the unfenced plots and subsequently counted and attributed to species of origin. For the six combinations of treatment and vegetation type pellet deposition rate was highly correlated with differences in the rate of change of species cover between fenced and unfenced plots and the lifeform composition of the vegetation. The greatest changes were observed in the clearfelled, burned area, while there was relatively little change in the undisturbed forest. Grass and herb species were generally disadvantaged by mammal exclusion while shrubs and graminoids generally grew faster in the fenced plots.