Can the disappearance of the forest orchid Goodyera repens be linked to clearcutting? : a spatial analysis using citizen science data from southern Sweden.

Sammanfattning: Habitat transformation through forestry has an impact on boreal species in northern Europe. In Sweden, even-aged plantations with clearcut harvesting are forestry practices that affect the understory vegetation. This study focuses on the red-listed Goodyera repens, a rhizomatous evergreen orchid. Because it is adapted to the stable environment of humidity and shade found in closed conifer forests, it is thought to be negatively affected by clearcuts. The aim of this project was to study the relationship between disappearances of G. repens and conducted clearcuts. Citizen science reports of presence and disappearance of G. repens from Artportalen in southern Sweden from 1997 to 2022 were used to define disappearance sites. A GIS analysis was conducted with this data together with information about carried-out clearcuts. In 13.9% of the sites a clearcut occurred in between presence and disappearance. This suggests that clearcutting may have caused G. repens to disappear in these sites, which is in accordance with the ecology of the species and previous studies. However, in 86.1% of the sites G. repens disappeared without being preceded by a clearcut, so there may be other reasons behind it. Half of the sites with clearcut between presence and disappearance observations had more than 66% of their surface area occupied by the clearcut. From the other half, most of them had less than 33%, suggesting that G. repens could be affected even by a small clearcut area in its proximity. Biases and errors from working with citizen science data should be considered, such as different observer’s experience, temporal efforts or spatial efforts. Today’s conservation efforts often focus on avoiding clearcutting where G. repens is present. However, this study shows that the disappearance of G. repens may be caused to a large extent by other factors. More research about the causes of its decline would be needed to improve G. repens conservation’s work.