Effectiveness of slash and burn treatments in controlling Acacia dealbata Link invasion

Abstract Slash and burn treatments are often recommended and employed for controlling the invasive tree Acacia dealbata Link. In this study, we aimed to evaluate the effectiveness of this approach. We established eight experimental blocks with burn, slash and slash-and-burn treatments distributed across central Portugal. The density and height of new seedlings and resprouts of the invasive alien plant were monitored for three years. Our results showed that slash treatments stimulated resprouting, while burn treatments promoted seed germination. Resprouts and seedlings were significantly taller in the slash treatments compared to the burn treatments. When combined treatments were applied, different combinations of slash-and-burn reduced the number of resprouts and seedlings; however, the minimum stem density remained at 6.5 stems m −2 , compared to 0 in the control plots. These results demonstrate that, under the conditions of this study, slash-and-burn treatments without follow-up interventions are not effective for controlling A. dealbata populations, despite their role in reducing the soil seed bank.