Skonhoft Anders
Department of Economics, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
J Environ Manage. 2005 Jul;76(2):167-75. doi: 10.1016/j.jenvman.2005.01.016. Epub 2005 Apr 21.
This paper analyses how different management schemes influence the exploitation and economics of a wildlife population--the moose (Alces alces)--that is both a value (harvesting income) and a pest (forestry damage). Two regimes are explored; the unified management scheme where the wildlife manager aims to find harvesting quotas that maximise the overall benefit of the moose population, and the market solution where the landowners follow their narrow self-interests and maximise their private profit. Because the moose is partly a migratory species, these regimes will differ both with respect to harvesting income and browsing damage, and the landowners will experience different profit. The unified scheme is very similar to the actual Scandinavian management, while the market solution is closer to the management policy one finds in North America. In the first part of the paper it is shown how the harvesting quotas and browsing damage under these two regimes are influenced by dispersal as well as other ecological and economic factors. In the last part of the paper it is demonstrated that under the unified management regime the present practice of neglecting migration may lead to sub-optimally sized populations of migrating moose and an overall economic loss. It is also shown that neglecting migration leads to a substantial profit transfer among the landowners. The model is supported by a real life numerical example.
本文分析了不同管理方案如何影响一种兼具价值(收获收入)和有害生物(林业损害)双重属性的野生动物种群——驼鹿(Alces alces)的开发利用及经济效益。探讨了两种管理体制;一种是统一管理方案,即野生动物管理者旨在确定能使驼鹿种群整体效益最大化的收获配额;另一种是市场解决方案,即土地所有者追求自身狭隘的利益并使私人利润最大化。由于驼鹿部分属于迁徙物种,这两种体制在收获收入和啃食损害方面会有所不同,土地所有者也会获得不同的利润。统一方案与斯堪的纳维亚地区的实际管理非常相似,而市场解决方案更接近北美地区的管理政策。在论文的第一部分,展示了这两种体制下的收获配额和啃食损害如何受到扩散以及其他生态和经济因素的影响。在论文的最后一部分,证明了在统一管理体制下,目前忽视迁徙的做法可能导致迁徙驼鹿种群规模未达最优,以及整体经济损失。还表明,忽视迁徙会导致土地所有者之间出现大量的利润转移。该模型得到了一个实际数值例子的支持。