Ökologische Vorrangflächen fördern Kulturlandvögel

Over large parts of Europe, biodiversity loss on farmland is an urgent problem. A suggested answer is to demand from farmers to implement ecological focus areas. Within the EU it is discussed how high the proportion of such ecological focus areas should be and of which quality they have to be. In Switzerland, since 15 years ecological focus areas are mandatory and the topic of several research projects. As a “report on work in progress”, this article outlines some current studies of the Swiss Ornithological Institute on the subject “Effects of ecological focus areas on agricultural birds”. The mean proportion of ecological focus areas on the utilised agricultural area in the Swiss lowland is 9.5%. Nevertheless, no substantial improvement of population sizes of typical farmland species is seen on a national scale. Research shows that, besides quantity, mainly the ecological quality of the focus areas is essential for the occurrence of many bird species. Thereby, the accessibility of food is an important factor for birds. Sparse vegetation as well as succession play a key role. For example, densities of some farmland bird species are highest in four to six year old wildflower areas/strips. Several case studies show that populations of some farmland bird species benefit from focus areas of high ecological quality. Based on statistical models, about 14% of high value habitat (focus areas with high ecological quality, semi-natural habitat outside the utilised agricultural area) is necessary in Swiss arable regions to increase populations of typical bird species to considerable densities. Farmers play a decisive role for the realisation of options promoting biodiversity. We could show that farmers, who got an advisory service providing whole-farm solutions optimising ecological and economic aspects, increase their biodiversity performance. The 24 advised farmers in the project agreed to increase the proportion of focus areas with high quality on their farms from 3.3% to 8.7% of the utilised agricultural area. Within the same project a tool was developed that is used to score the diff erent options promoting biodiversity. An evaluation of this credit-point-system on 133 farms shows that the point score is an adequate and objective proxy for the biodiversity performance of farms. In Switzerland, there is a strong demand for ecological and environmental friendly produced label products. The Swiss organisation for integrated farming (IP-Suisse) focuses on the promotion of biodiversity and demands a certain ecological performance from all its producers, which is measured with the above-mentioned credit-point-system. Thus, biodiversity is an added value that can be turned into financial benefit for producers by higher prices.
Keywords: ecological focus area, quality, quantity, biodiversity