Effekt av brand och bete på uppkomst av örtartade växter i restaurerade betesmarker. En jämförande studie

Abstract

Open ecosystems, such as grasslands and pastures, have naturally been shaped by disturbances like fire and grazing. These processes play a crucial role in creating habitats with high biological diversity, particularly favourable for a wide range of herbaceous plant species. In recent years, many of these disturbances have ceased, leading to encroachment, fragmentation and habitat loss. The aim of this study was to examine and compare the effects of fire, herbivory and a combination of fire and herbivory on the emergence of herbaceous plants. The study was conducted at the Ecopark at Nordens Ark. A seed mixture was sown in plots undergoing the different treatments: fire, herbivory and their combination, in autumn 2024. In spring 2025, an inventory was done to assess total emergence, species richness and the emergence of Agrostemma githago (corncockle), a dominant species in the plots from the seed mixture. The results clearly showed that grazing was the key factor contributing to higher total emergences, greater species richness and a higher number of A. githago. The highest mean values were observed in plots with combined fire and herbivory, but no significant difference could be observed to grazing alone. Fire alone resulted in significantly lower emergence and species richness than treatments including grazing but still had a weak positive effect. These findings indicate that grazing creates favourable conditions for increased emergence of herbaceous species, likely by reducing competition from grasses and therefore increasing light availability at the soil surface. Grazing thus appears to be a more effective management tool for maintaining open ecosystems than fire, which is valuable information regarding restoration and management of open ecosystems. The study shows that herbivory, and potentially fire, act as key processes to keep open ecosystems open, thus promoting recruitment of herbaceous plants, which preserves the habitats high biodiversity, ecological function and cultural-historical value.