Effects of non-native species and ecological restoration on network structure and ecosystem function

Abstract

Non-native species pose a signi cant threat to biotic interactions, such as plantpollinators, and associated ecosystem functions. Ecological restoration is commonly used to mitigate or revert the impact of non-native species. The removal of nonnative plants is one frequently used restoration approach to minimise competition for resources between native and non-native plants, which facilitates the recovery of native plant communities. Many aspects of how ecological restoration impacts native ecosystems are not well understood. For example, the conditions that allow ecological communities to thrive after restoration can take years to develop. Although restoration interventions ideally aim to address most impacts of non-native species, we know little about the response of non-target species, both native and non-native. In this thesis, I explore the effects of non-native species and ecological restoration on plant-pollinator communities and pollination function on the island of Mahé, Seychelles, in the Western Indian Ocean. I used a community-level restoration experiment with honey bee (Apis mellifera) supplementation to study the medium-term responses of plant-pollinator interaction networks to management interventions. Initial restoration took place in 2011, and the datasets used here were collected across two consecutive years (2018/19 and 2019/20).