Monitoring changes in landscape structure in the Adirondack-to-Laurentians (A2L) transboundary wildlife linkage between 1992 and 2018: Identifying priority areas for conservation and restoration

Context Although many species have transboundary geographic ranges, most conservation initiatives do not cross political boundaries. The landscape between the Adirondack Mountains in New York and the Laurentian Mountains in Québec includes one of three potential north–south transboundary wildlife movement linkages that connect wilderness areas in northeastern USA and southeastern Canada. Although this region still maintains habitats of high ecological integrity and biodiversity, increasing land-cover changes and fragmentation are putting landscape connectivity at risk. Objectives We measured changes in landscape composition and configuration within the Adirondack-to-Laurentians transboundary wildlife linkage (A2L) between 1992 and 2018 to identify priority areas for conservation and restoration. Methods Land-cover change was calculated by measuring area and proportion of land-cover classes, and landscape fragmentation was determined by measuring patch number, mean patch size, the effective mesh size, and road density, at three spatial scales and four fragmentation geometries (i.e., combinations of fragmenting elements). Results Extensive changes in land-cover and landscape fragmentation occurred within the A2L between 1992 and 2018. Forest areas declined by 1363 km 2 and wetlands declined by 1365 km 2 (69%). This was most pronounced in the Québec portion of the A2L where wetland areas declined by 872 km 2 (88.5%). Forest areas in the Québec portion experienced the greatest amount of fragmentation with a m eff_CUT decline of 3262.5 km 2 (58.5%) since 2000. Conclusions Coordinated and collaborative transboundary conservation efforts help improve protection of species with transboundary ranges. Monitoring of land-cover changes and landscape fragmentation is an effective way to identify priority areas for conservation and support transboundary coordination. Strengthening conservation strategies that enhance landscape connectivity and protect ecosystems at the local level will help achieve post-2020 biodiversity commitments at the national and transboundary levels.