ABSTRACT Aims Although pastures used for dairy production are typically managed intensively, they can contribute substantially to plant diversity, depending on how grazing is implemented. While numerous studies have investigated the individual effects of grazing intensity and stocking method in terms of rotational or continuous stocking on the vegetation, experimental work widely neglects their potential interactions. We examined whether the effect of grazing intensity on plant diversity measures in dairy pastures is dependent on the stocking method and the regional context. Location Agricultural grasslands on dairy farms in Northern and Southern Germany. Methods We conducted botanical surveys on 68 grazed permanent grassland sites on dairy farms across Germany. Diversity measures included species richness, species evenness (Simpson Equitability), and Simpson Index. Plant functional strategies were derived at the site level using the CSR classification (competitive, stress‐tolerant, ruderal). We used linear mixed‐effects models to test the effects of grazing intensity (expressed on a continuous scale), stocking method (continuous vs. rotational), and region and their interactions on plant diversity and functional strategies. Results Species richness and the S‐component of the functional signature declined significantly with increasing grazing intensity, independent of stocking method and region. In contrast, the effect of grazing intensity on species evenness was more complex. While we found no variation when comparing either different stocking methods or levels of grazing intensity, species evenness increased with higher intensity under rotational stocking but decreased under continuous stocking in the North. The opposite pattern was observed in the South, although less pronounced. Conclusion Our results show that the effects of grazing intensity on the botanical diversity of dairy pastures depend on stocking method and regional context, and that responses can differ depending on the diversity measure under study. Accounting for these factors can avoid misleading conclusions when assessing management strategies and deriving conservation recommendations.
Wild et al. (Wed,) studied this question.