Forming plant management strategy with the aid of population models
Originally from the Caucasus, the giant hogweed (Heracleum mantegazzianum) is an unwelcome visitor in Europe's ecosystems. It has been shown to negatively affect local biodiversity and also poses a health threat to humans that come into contact with the plant. In response, the European Commission funded a group of universities and research institutes to develop a sustainable approach to managing invaders like the giant hogweed. Part of the work targeted the development and use of population models to learn about plant behaviour in various conditions. Scientists at the UFZ Centre for Environmental Research in Germany drew on concepts from matrix population models and spatially explicit individual-based models to create a new model capable of accounting for the complex behaviour of the giant hogweed. Model output compared well with real data, including population estimates derived from aerial photographs. UFZ's investigation uncovered important findings relevant to the development of reduction measures. First, the giant hogweed is able to go dormant when food or other resources become scarce, allowing it to survive in inhospitable conditions. A second mechanism, long-distance seed dispersal, enables colonisation of new areas when current habitats become untenable. In order to overcome these defence mechanisms, the UFZ recommends that control measures be implemented rigorously over a considerable time period, preferably five years or more. In this way the threat of the giant hogweed can be eradicated. Dissemination of this information to the appropriate audience is in progress.
