Effects of mowing frequency on grassland flora and fauna: implications for the conservation of semi-natural grasslands in Europe

Abstract

To maintain the high biodiversity and preserve the conservation value of semi-natural grasslands, management like grazing or mowing is necessary. Given the limited resources available for management, and few remaining areas, the best management method and intensity should be used. However, the evaluation and comparison of effects of different management intensities on a larger scale is often challenging, as most studies have a limited scope (e.g. only investigating effects in one grassland or for one type of organism). In view of this, we used meta-analysis methods to explore effects of different mowing intensities on biodiversity on a European scale, to reach more robust conclusions. We included studies examining effects of annual mowing compared to both more and less frequent mowing, e.g. twice a year or every other year, on European grassland flora and fauna. Our results suggest that mowing more frequently than once per year has a more positive effect on grassland biodiversity, especially in more productive grasslands. However, differences in effects between frequencies were small, suggesting that mowing more seldom could be a viable management option. This meta-analysis is an example of how ecological knowledge can be compiled to contribute to evidence-based conservation policy and more cost-effective management.