© Markus Jenny
How do landscapes change over time for farmland birds? A national monitoring project initiated by the Swiss Ornithological Institute shall provide answers to this question.
The project aims at developping and testing a method to monitor the quantity and state of habitats in farmland over time.
In 2005, the Swiss Ornithological Institute and the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) tested the method in 25 1-km-squares distributed all over Switzerland. The method combined interpreting aerial photographs and field-based verification of the habitats within the 1-km-squares. Censuses by two independent persons showed the high reproducibility of this method.
So far, data on quantity and quality of habitats for farmland species and their population trends on a national level have largely been unknown. This has impaired the interpretation of population changes of birds, a difficulty encountered already in the National Biodiversity Monitoring (BDM) and in various monitoring programmes of the Swiss Ornithological Institute.
On aerial photographs, structural elements such as hedges and single trees can be localised and mapped with high precision. Habitat quality, however, can sufficiently be assessed only in the field. Independent mappings of two field workers revealed high consistence of the results. For details, please ask for the final report.