Authors: Hoffmann, Monika; Bartoń, Kamil;Ostapowicz, Katarzyna;Ibisch, Pierre ;Selva, Nuria;

Roadless Areas (RAs) continue to be underestimated in their contribution to protecting ecosystem functionality and biodiversity. A main constraint for the take-off of RAs research is the lack of open-source road datasets that are complete enough to identify RAs of conservation value. We conducted a comparison of RAs using OpenStreetMap in the Canadian boreal biome and the temperate biome of Central Europe. Using a 1km buffer for all OpenStreetMap roads, we identified in total 16,786 RAs in Canada (4,560,608 km², representing 84% of the area) and 3,524 RAs in Central Europe (2,160.6 km², only 0.41% of the area). Then, we tested the accuracy of RAs identification in the boreal biome in Canada using two methods (1)1000 random points buffered with 1km radius, and (2)30 randomly selected RAs; both were visually-manually checked for unmapped roads. In Canada, 26.1% of the buffered points contained roads, of which 23.2% contained unmapped roads; 68% are RAs and were predominantly located in the northern region of Canada. We documented a loss of 68% of roadless surface after manual road-mapping in boreal Canada, a region considered largely unfragmented. This study aims to emphasize the importance of accurate road mapping to identify remaining RAs of ecological value.
We gratefully acknowledge support by the National Science Centre Poland, project TRACE [no. 2018/29/B/ST10/02979]. Global Land Programme contributing project.