Betydelsen av urbana bostadsgårdars ålder för dess artrikedom av inhemska örtartade växter och förekomst av fåglar

Sammanfattning: Life on Earth is currently experiencing a sixth species extinction, where urbanization, as one of the main driving forces, fragments and causes losses of near-urban habitats. At the same time, a rich variety of habitats can be found in urban landscapes that may harbour biodiversity. Knowledge of how urban ecosystems develops over time is fundamental for application of relevant nature conservation measures that promote species richness. This study aims to shed light on the importance of age in urban residential yards for the species richness of native herbaceous plants and of birds. The study was carried out in Linköping during the summer of 2023, and it included surveys of native herbaceous plants and birds in three area types (natural area, old and young residential yards). In total, 114 species of native herbs and 34 species of birds were found. Sites in the natural area had (mean ± SE) 25,8 (± 1,8) and 6,6 (± 0,7) species of plants and birds respectively, whereas the corresponding values for old residential yards were 23,2 (± 1,2) and 5,7 (± 0,5) and for young residential yards 19,9 (± 1,3) and 3,3 (± 0,7). Jaccard's coefficient showed that the largest proportion of shared species occurred between ‘old’ and 'young' residential yards. Overall, the results of my study showed some support for my prediction that age of residential yards is important for species richness of native herbaceous plants and birds. The results indicate that urban environments (old and young residential yards) harbour a selection of species that can withstand anthropogenic disturbance.