Faktorer som påverkar orkidé artrikedom och artsammansättning på myrar i Sverige : - Latitud, area och mänsklig påverkan

Sammanfattning

Orchids are plants belonging to the Orchidaceae family, a diverse group containing many specialist species affiliated with mires and other wetland habitats. This study examines the effect of latitude, mire area and mire ditching on orchid species richness and species composition in Swedish mires. Data was compiled from ecological field surveys conducted by AFRY. In total 116 mires were included in the dataset. For every mire, species presence/absence, latitudinal position, mire area and drainage impact within 25 m and 50 m from ditches were noted using GIS. The statistical analysis was conducted using RStudio where three different models were used. Poisson-GLM was used to calculate species richness, and a Jaccard-distance based PERMANOVA along with variance partitioning was used to determine species composition. The results show that mire area had the strongest positive effect on orchid species richness, while geographical position contributed more to variation in species composition. Drainage showed a weak effect on species richness and did not have a significant impact on species composition. The results from this study could aid in ecological restoration attempts on mires and help better understand some of the key factors that influence orchid diversity on Swedish mires.