The importance of vegetative seedling traits in distinguishing herbaceous legumes of differing impact in temperate natural ecosystems

摘要

Many herbaceous legumes are important economic plants that have also become a common component of the naturalised flora of temperate Australia. They have successfully infiltrated natural ecosystems, but species differ in their ability not only to naturalise but also in their weed impact. The level of impact of a naturalised plant species is an important determinant of its seriousness as a weed. Being able to distinguish minor weeds from those that cause large impacts allows species to be effectivelyprioritised for management. Identifying which biological characters are common only to the most, or conversely only to the least, weedy species would also be a useful predictive technique. A number of seedling characters were explored in an attempt to distinguish between herbaceous legumes of differing impact. A lower specific leaf area appeared to be a feature of the highest impact herbaceous legumes studied. A possible advantage of this may be the presence of some leaf defence mechanism to herbivory resulting in increased seedling survival and/or vigour. However, the importance of specific leaf area in the weed risk assessment of herbaceous legumes is questioned.