Exclosure experiment data

This study investigates how invasive fallow deer (Dama dama) affect the regeneration of eucalypt woodlands and forests in Tasmania, where native vegetation lacks structural defences against large herbivores. We tested whether juvenile eucalypts are more likely to survive and grow in "safe sites"—microsites where they are protected by dense, prickly understorey plants known as nurse plants. Field surveys showed that eucalypt seedlings were significantly more likely to occur within these protective patches than in open areas, particularly where deer activity was high. In areas without sufficient nurse plant cover, seedlings experienced greater browsing damage, reduced growth, and developed disproportionately large lignotubers—a stress response to repeated herbivory. These findings suggest that nurse plants provide associational resistance, helping shield seedlings from deer. The results highlight a spatial bottleneck in eucalypt regeneration caused by deer, which may ultimately alter woodland structure and composition. Without intervention, grassy eucalypt woodlands may shift toward shrub-dominated or treeless systems dominated by browsing-resistant species.