Browsing by Subject "economic optimization"

Reindeer (Rangifer tarandus L.) is an integral part of ecosystems across the northern boreal regions, and reindeer husbandry is an important socio-cultural factor, especially for indigenous people. Currently, reindeer husbandry in Fennoscandia is confronted with deterioration of pasture areas, and the decreasing of reindeer number has often been offered as a solution. However, in most reindeer herding districts, forestry has also strongly decreased the sustainable production capacity of winter pastures and therefore has had a significant role in pasture deterioration in addition to high reindeer numbers. The interaction between forestry and reindeer husbandry has often been studied qualitatively, ecologically, or with simple bio-economic models from the perspective of forestry. In this thesis, I use a detailed interdisciplinary ecological-economical model to study how the rotation forestry affects the economics of reindeer husbandry. The research questions are 1) how does the length of forest rotation period and 2) the management practices such as soil scarification and leaving of harvesting residues affect the economically optimal reindeer husbandry. I expand a novel ecological-economical reindeer husbandry optimization model to include the effects of forestry on the ground and arboreal lichen with an assumption of normal forest structure. The effects of forestry on the ground and arboreal lichen are based on previous literature. Modern dynamic optimization algorithms are used to solve the model for the optimal number of reindeer, annual net revenues, lichen biomass on pastures, and the level of supplementary feeding under different forest rotation lengths and management scenarios with zero and positive interest rates. The results show that the length of forest rotation period affects the economically optimal solution. When pasture rotation is used, shortening the forest rotation length decreases the optimal number of reindeer, annual income, and the lichen biomass in pastures, but increases the amount of supplementary feed given. When pasture rotation is not used, shortening the forest rotation length decreases the number of reindeer, annual net revenues, and supplementary feeding, but increases the lichen biomass. Soil scarification and harvesting residues lower the annual net revenues of reindeer husbandry by 1-15% depending on the forest rotation length and pasture rotation. The longer is the forest rotation length, the less the annual net revenues are affected by the forest management practices. Higher interest levels lead to higher reindeer numbers and a higher level of supplementary feeding, but also to lower lichen biomass and annual net revenues from reindeer husbandry. The results of this thesis support the earlier findings of negative effects of rotation forestry and short rotation lengths on reindeer husbandry, and estimations that reindeer husbandry is more resilient if pasture rotation is used. As the economical sensibility of rotation forestry in Lapland has currently been questioned, even-aged forestry could offer a solution with the best management scenarios for both parties. The results of this thesis support infinitely long forest rotation length without soil scarification. This thesis also highlights the need for interdisciplinary co-design of ecological studies to ensure that they are suitable for creating complex interdisciplinary optimization models.