Abstract

The substantial reduction in the area of semi-natural grasslands due to the intensification of agriculture and silviculture has resulted in a dramatic decline of species that depend on these habitats. Simultaneously, the area of grassland habitats along infrastructure such as power lines and roads continues to increase and can even surpass the area of semi-natural grasslands of high nature value. In this thesis, I aimed to explore to what extent linear infrastructure habitats contribute to the biodiversity of plants and flower-visiting insects and landscape connectivity. I showed that the presence of power-line corridors in the landscape positively influenced the alpha and gamma diversity of plants, but that this habitat had no effect on beta diversity. Road verges and power-line corridors had as high alpha diversity of plant and insect species as semi-natural pastures of high nature value. Despite the fact that road verges increase the structural connectivity in the landscape, they did not strongly influence the alpha, beta or gamma diversity of plants, butterflies or bumblebees in other grassland types. Further, I found that road verges are corridors for flower-visiting insects irrespective of their diversity of flowering plants. My results also showed that roads are barriers to the movements of flower-visiting insects regardless of the traffic intensity of the road, and that traffic mortality rates of bumblebee queens increase with increasing traffic intensity. Finally, my thesis highlights that the contribution of linear infrastructure habitats to landscape connectivity for flower-visiting insects can be constrained by the behavioural responses of individuals to these habitats and by an increased mortality risk.

Keywords

alpha-, beta-, gamma-diversity, functional connectivity, structural connectivity, road mortality, corridors, barriers, behaviour, semi-natural grasslands

Published in

Acta Universitatis Agriculturae Sueciae
2021, number: 2021:63
ISBN: 978-91-7760-803-5, eISBN: 978-91-7760-804-2
Publisher: Swedish University of Agricultural Sciences

SLU Authors

• Dániel-Ferreira, Juliana

  • Department of Ecology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Ecology


Permanent link to this page (URI)

https://res.slu.se/id/publ/114076