Grazing and boundaries favour weedy plants with functional traits beneficial for pollinators

Abstract

Semi-natural grasslands are key habitats for biodiversity, yet are negatively affected by intensified land-use. To mitigate such adverse effects, effective subsidies systems encouraging extensified production need to be developed that focus not only on species richness and functional diversity. We evaluated the effect of two grazing intensities and the effects of landscape complexity on plant functional traits in three grassland types in the Great Hungarian Plain. Regarding plant traits responding to grazing, we found shorter-statured and earlier flowering species in intensively grazed pastures and more disturbance-tolerant species with increasing boundary length. For pollination-related plant traits, there were more later flowering species in extensively grazed sites, while flowering duration and flower colour revealed complex relations between landscape complexity and grazing intensity. Generally, local low-intensity grazing (0.5 cattle/ha) supports specialist plant species, and increasing boundary length promotes generalist disturbance-tolerant species with traits beneficial for pollinators. Especially when designing new agri-environment schemes for low-intensity grazing systems, understanding the complex functional relationships is crucial to maintaining and restoring farmland biodiversity.