Finding common ground in commercial forests: Sheep grazing, timber production, and carnivore fences

Sheep ( Ovis aries Linnaeus, 1758) grazing has the potential for positive impacts on commercial forestry through weeding competing plants, or to be detrimental if browsing and trampling levels are high. In some regions of Norway, large, forested areas are fenced to minimize depredation risk from recovering carnivore populations on unsupervised sheep, but fences may alter the behavior of sheep leading to differential effects inside and outside of these fences. We estimated Norway spruce ( Picea abies (Karst.) L.) sapling growth and frequency of damage in Inland and Trøndelag counties Norway, and related these to grazing intensity, fenced status, and competing vegetation along 70 transects within 8 fenced and 11 unfenced clearcuts during August 2024. We found that growth of terminal leaders decreased with increasing grazing intensity inside fences, whereas growth increased along with grazing intensity outside fences. Sheep grazing in our study had a positive effect on spruce sapling growth form by decreasing slenderness, measured by height-to-diameter ratio, both inside and outside fences. While less than three percent of saplings were browsed overall, browsing of saplings did increase at higher grazing intensities. Trampling was negligible on all transects. Our results suggest that sheep grazing is compatible with spruce regeneration and carnivore fencing as negative impacts from increasing amounts of sheep resulting in reduced growth of terminal leaders may have been offset by decreasing height-to-diameter ratios. Lower height-to-diameter ratios suggest more resilient saplings that could make them better able to withstand stressors. However, if sheep are allowed to reach high grazing intensities, this balance may not be achieved as browsing increases. With increasing demands on forested landscapes, integrating sheep grazing in carnivore-resistant fences on commercial forests presents an opportunity for multiple-use land management with minimal associated trade-offs. • Sheep grazing, timber production, and carnivore-resistant fences were compatible. • Sheep inside and outside fences affected spruce sapling growth differently. • In all cases, grazing was associated with greater robustness of spruce saplings. • Browsing was infrequent but did increase as grazing intensity intensified.