Dangerous and useful at the same time: management strategies for the invasive black locust.
The North American black locust (Robinia pseudoacacia) is considered controversial as many other introduced tree species because of its both positive and negative properties. Based on a literature review and own data we analyze the occurrence of black locust in Czechia and Switzerland and present the management approaches in place. In both countries, black locust is on the blacklist of invasive introduced species. It can grow in a wide range of habitats from urban and agricultural landscape to dry grassland and forest. Meanwhile, the species became in many places part of the environment and human culture, so that neither unrestricted cultivation nor large-scale eradication is feasible. We suggest a context-dependent management which respects the different needs and takes into account the local environmental conditions, land-use, habitat type, risk of spread as well as economic, cultural and biodiversity aspects. To this purpose we propose three management strategies: (1) control respectively gradual suppression of black locust in forests where the species is not welcome, (2) its eradication in sensitive ecosystems as dry grasslands or clear and dry forests and (3) its tolerance in intensively managed agricultural landscapes and in urban environment.