Ökologische Bewertung von Waldrändern: ein Methodenvergleich

Abstract

Ecological assessing of forest edges: comparison of two methods In Switzerland, forest edges are mostly man-made. Potentially, forest edge ecotones are very rich in species. In agricultural landscapes, they are also the main element of ecological connectivity. Unfortunately, today's forest edges are mostly far too narrow and monotonous to optimally fulfil their role. Some years ago, therefore, the federal government started a programme to improve the ecological quality of forest edges. Of course, the impact of the programme should be monitored and several assessment methods were developed. In the present paper, we compared the assessment methods of Pro Natura and Krüsi by applying them to eleven upgraded and three untreated forest edges. Even though both methods take into account the structure and the floristic richness of forest edges, they differ in many details. One major difference is that the Pro Natura method is based on estimates while the Krüsi method whenever possible relies on measurements. With both methods, it was possible to distinguish valuable from less valuable forest edges and, fortunately, the results of both methods even highly correlated. In conclusion, for a quick assessment by lay men, the rapid and simple Pro Natura method is recommended, whereas for scientific monitoring, the more reproducible and more sophisticated but also more time-consuming Krüsi method is more suitable.