Riparian forest buffer management in Norway: Evaluating adherence to certification standards

• Evaluating harvest impact on buffer composition under certification. • 45 % of the buffers complied with the certification requirements. • Pre-harvest buffer composition did not explain narrow buffer width. • Structural variation in tree diameter was maintained after harvest. Riparian buffers are important for maintaining the ecological function of the riparian forest surrounding watercourses upon harvest. The Programme for the Endorsement of Forest Certification (PEFC), the world’s largest certification system by forest area, regulates harvest along watercourses. In Norway, riparian buffers are managed through a combination of detailed requirements and subjective assessments. Despite the importance of riparian buffers, significant knowledge gaps remain regarding their management and how well subjective assessments align with certification intentions. This study aims to investigate how subjective assessments are applied to riparian buffers in Norwegian forestry and whether their management complies with the 2015 PEFC standard. We carried out inventories of 27 randomly selected stands in South-Eastern Norway, focusing on species composition, stand structure, and site conditions. We found that the mean and median buffer widths were 7.0 m and 5.7 m, respectively. Eighty-five percent of the buffers were narrower than the prescribed standard width of minimum 10 m, yet 46 % of the stands still met certification requirements due to exemptions allowing reduced buffer widths. While the largest trees were harvested, overall composition of the riparian buffer and tree structure were largely maintained after harvest. We found no site characteristics that could explain the narrow buffers and the results indicate that a buffer width norm narrower than the requirement has been established. The PEFC water-protection requirements are yet to be fully implemented in forest management in Norway, and improvements are warranted from companies responsible for forest planning, harvest and silviculture.