Seed dispersal by European bison (Bison bonasus) and fallow deer (Dama dama) : implications for biodiversity

Sammanfattning

The decline of animal dispersers poses a global threat to plant communities already challenged by climate change and habitat fragmentation. Herbivores with broad diets and large home ranges, such as the European bison (Bison bonasus) and fallow deer (Dama dama), are crucial for maintaining seed dispersal networks by endozoochoric dispersal. This study investigates the number of plants and species germinating from the dung of wild and captive populations of European bison and fallow deer, with the goal to assess their potential impacts on biodiversity. Faecal samples for both species were collected from two captive populations in Poland (Pszczyna) and Sweden (Eriksberg) and one wild population in Poland (Forest District Drawno). Droppings were stratified and cultivated in optimal greenhouse conditions for ten weeks. The results indicate that both European bison and fallow deer are capable of being efficient seed dispersers. European bison, however surpassed fallow deer across all sites in both seedling abundance and species richness. Furthermore, European bison dispersed five unique species of plants that did not appear in any fallow deer faecal samples. The unique dispersal profile of the European bison, thus, appears to be particularly valuable for biodiversity restoration efforts.