Epsilon Archive for Student Projects

Abstract

Ecosystem degradation has driven global restoration efforts aimed at recovering biodiversity and ecosystem services. Intensive forestry practices in Sweden’s boreal forests have altered forest structure, thereby impacting biodiversity. This study assesses whether forest restoration enhances habitat complexity and supports bird diversity, using birds as indicators of ecological health. Passive acoustic monitoring (PAM) was employed to record bird vocalizations across 30 forest stands in two of Sveaskog’s Ecoparks, one in northern (Käringberget) and one in southern (Hornsö) Sweden. Each Ecopark includes forest stands representing three treatment types: target, restored and unrestored. Structural habitat variables such as deadwood volume, basal area, and understory cover were measured to evaluate habitat complexity. Results showed that restoration increased structural similarity between target and restored stands, particularly in Hornsö, while unrestored stands remained distinct. Bird species richness and community composition showed limited overall responses, though certain functional traits and indicator species reflected treatment differences. Structural variation within stands and subtle bird responses suggest that restoration is a gradual process, with key features like deadwood volume and conifer basal area playing important roles in shaping bird assemblages. This study highlights the value of combining structural metrics and PAM to evaluate restoration outcomes for forest and bird biodiversity.