U. Schaffner, D. Kleijn, V. Brown and H. Müller-Schärer

Veratrum album in montane grasslands: a model system for implementing biological control in land management practices for high biodiversity habitats. BNI 22 (1)

Abstract:

Low-input agriculture on montane grasslands as practised until the mid 20th Century, has promoted local biodiversity by creating and maintaining open and semi-open habitats below the timberline. Today, socioeconomic trends lead to management intensification in nearby grasslands and to abandonment of more remote grasslands; either of these trends puts the local biodiversity under pressure. One especially time-consuming and costly activity in montane alpine grasslands is weed control. In Europe, broadcast application of chemical control is not recommended or not even allowed because the available herbicides are unselective, and treatment of individual plants, either chemically or mechanically, is extremely labour-intensive. Stakeholders are therefore urged to develop new control concepts that are economically affordable and highly selective. The implementation of biological control into existing management schemes may provide an appropriate strategy for management of the most problematic montane grassland weeds. In order to develop effective biological weed management strategies, it is necessary to (a) identify life cycle transitions of the weed that are both amenable to manipulation and influential on population growth; and (b) combine control due to natural antagonists and limiting resources. Veratrum album is an important weed on grazed montane grasslands, because it exhibits acute toxicity to mammals and locally displaces fodder plants. This paper reviews the available information on the ecology of V. album and its natural antagonists, and explores prospects for its biological control. It is suggested that this species and its antagonists provide a promising model system for exploring the possibilities of implementing biological weed management within existing and future management schemes of montane grasslands.