Epsilon Archive for Student Projects

Abstract

Nynäshamn municipality, located in Stockholm County, is connected to the capital via National Road 73, which constitutes a barrier to wildlife. A mitigation measure in the form of an overpass was constructed to enhance the lost habitat connectivity. However, the municipality's growth plans include significant expansion of the urban sprawl by 2040, which will threaten wildlife by fragmenting habitats and increasing disturbance near the overpass. This thesis investigates the impact of urbanization on local wildlife and assesses the efficacy of the overpass, aiming to restore wildlife connectivity with green corridors and proposed design improvements to the overpass.

Analysis revealed time-separation in human and wildlife usage of the overpass, suggesting that co-usage is feasible without significant impacts on wildlife. Moreover, the thesis studies the habitat requirements of moose with the aim of improving the overpass efficacy and habitat connectivity. The Wildlife Habitat Relationship (WHR) method identified moose’s habitats and highlighted the scope of their fragmentation, also emphasising overpass to be the only sufficient habitat connection in the area. Consequently, a proposal for a revised overpass was developed together with a design for habitat connectivity in the form of green corridors.

Proposed overpass improvements include removing dense vegetation at the entrance, replacing it with ground cover species preferred by moose, extending acoustic screens to reduce light and noise disturbances, and adding natural features like rock and branch piles inspired by the Sandsjöbacka ecoduct. Moose habitats were conceptualized based on life requisites, including feeding, cover, and reproductive areas, highlighting the importance of lakes, ponds, wetlands, and various vegetation types for habitat connectivity.

Despite the complexity of urbanization impacts this thesis recommends protecting habitat connections by limiting urban sprawl and establishing land protection measures. In conclusion, the thesis presents design recommendations to develop wildlife corridors and improve overpass efficiency, aiming to enhance wildlife populations in Nynäshamn while promoting coexistence and ecological sustainability.