Avskjutning av älg över tid och rum – effekter av rovdjur och skogsbruk

Moose hunting and forestry are important parts of the cultural heritage of Inner Scandinavia, where the use of forests and moose as natural resources are connected. During the middle of the twentieth century, the moose population has increased in numbers due to the introduction of stand forestry practices, which has provided moose with increased access to forage in areas with young forest stands. This has resulted in more hunting opportunities. The moose hunt has great economic as well as recreational value, while the winter grazing of moose on young forest stands leads to large losses for landowners through deteriorating timber quality and lowering biomass production. In addition to the human impact on moose through forestry and hunting, large predators influence the dynamics of moose populations. Local management of moose populations to the desired density and/or demographic composition is therefore affected by presence of wolves and bears, in which predation affects the possible harvest yield and the age and sex composition of harvested animals. The aim of this study is to 1) provide an overview of moose harvest in Inner Scandinavia at regional and local levels across the Norwegian-Swedish national border, and 2) analyze the factors affecting the variation in moose harvest with a focus on presence of large predators, effects of forestry, occurrence of roe deer (the second most common prey for wolves after moose), and along a landscape gradient. We used harvest statistics from the period 1995-2020, monitoring data from annual census of wolves, number of bears shot annually, proportion of agricultural land (index for roe deer density), proportion of young forest per year, and latitude to explain the variation in moose harvest over time and between different administrative units in Sweden and Norway. The study shows a variation in moose harvest both between different moose management units in Sweden and Norway and within the countries during the most recent decades. Over the study period 1995-2017, harvest density was on average 50% (Sweden) and 40% (Norway) lower in moose management units completely overlapping wolf territories compared to areas without wolves. The presence of wolves and bears affected both the total harvest and the proportion of adult females out of harvested adult individuals. In most moose management units, harvest density increased with an increased proportion of young forest, probably due to an increased supply of forage that can affect moose density, but also the distribution of moose in the landscape. On the other hand, the roe deer density did not explain any of the variation in moose harvest, suggesting that roe deer density in Inner Scandinavia is too low to result in a reduction of wolf predation on moose. The total harvest did not vary with latitude, but the age and sex composition of the harvested animals showed some variation in relation to latitude in Sweden but less in Norway. An important result from this study is the differences between Sweden and Norway for distinct moose management units. The observed variation may be partly due to differences in the actual environment that we did not account for, but also due to differences in the moose management, both historically and today. Overall, this study shows a significant impact of wolves and bears on moose harvest, but the annual hunter harvest is usually larger (2.4-3.5 times) than the predation from wolves.