Boar feeding grounds: how wild boar populations affect localised landscapes and ecosystems

The recent recolonisation of wild boar (Sus scrofa) across the Swedish landscape has caused substantial impacts on agriculture and has raised concerns about potential consequences for local ecosystems. This thesis aims to enhance our understanding of how wild boar activities affect various ecosystem and landscape elements, as well as to investigate the role of supplementary feeding in mitigating their impact. By combining long-term telemetry data and purpose-directed manipulative experiments, I assessed the impacts of wild boar at various ecological scales. I found that wild boar have extensive and direct effects on agriculture, as well as on both faunal and floral communities. My results suggest that foraging habits of wild boar are expected to continue causing adverse effects on crops and farmland, and that the effectiveness of supplementary feeding in mitigating damage caused by wild boar to agricultural areas remains uncertain. Within the Swedish forest landscape, where modern forestry practices predominate and few natural disturbances occur, wild boar rooting behaviour may provide an ecologically significant form of disturbance that enhances biodiversity. Changes at a broader ecosystem community scale may result from altered resource use by sympatric ungulate species and potential cascading effects following changes in plant communities and habitats. The findings of my thesis indicate that with an inevitable growth in wild boar populations, we may face substantial impacts on habitats and biodiversity, with both positive and negative outcomes. Moreover, human-driven ecological manipulations, such as supplementary feeding, are likely to accentuate these effects and should, therefore, be considered from a broader perspective before implementation.