Ville Kankaanhuhta

Reliability of self-control method in the management of non-industrial private forests

This study seeks to determine the extent to which self-control data can be relied upon in the management of private forests. Self-control (SC) requires the forest workers to evaluate their own work quality to ensure the clients’ needs are met in terms of soil preparation, planting and young stand management. Self-control data were compared to an independent evaluation of the same worksites. Each dataset had a hierarchical structure (e.g., sample plot, regeneration area and contractor), and key quality indicators (i.e., number of mounds, planted seedlings or crop trees) were measured for each plot. Self-control and independent-assessments (IA) were analyzed by fitting a multivariate multilevel model containing explanatory variables. In the silvicultural operations studied, no practical differences for the quality control purposes were found. This was the case especially in soil preparation (number of mounds) and young stand management (number of crop trees). Self-control seemed to give about 10–20% overor underestimation depending on key quality indicator as compared to independent assessment. Discrepancies were discussed in terms of sampling and other explanatory factors. According to overall results, self-control methods are reliable at the main stages of the forest regeneration process. As such, the diverse utilizing of self-control data is possible in support of service providers operations.