Managing Multi-Species Forests To Minimize The Risk of Biodiversity Loss

The design and implementation of forest management systems affects the risk of biodiversity loss. Using a well-known competition-colonization metapopulation model of multiple competing species along with optimal control theory, we investigate both analytically and numerically the design of forest management system in an implicitly spatial context. We focus on the two major approaches to forest management: uniform and specialized. Under uniform management the whole forest estate is jointly managed for the production of timber and the conservation of biodiversity. In contrast, under specialized management the forest is divided into more or less exclusive management zones for timber production or biodiversity conservation. When the model is parameterized to mimic the management of a diverse Malaysian tropical rainforest, the nonlinear dynamic relationships among species, along with interactions between economic and ecological factors, strongly influence the relative superiority of the two management approaches. In the sense of minimizing risks to floral diversity for a given level of timber harvest, the results indicate that in communities where biological trait differences between species are small, specialized management is superior to uniform management for the vast majority of situations. In contrast, in floral communities where biological traits vary between species, uniform management is often superior to specialized management. In addition, small changes in the discount rate or collateral harvesting damage can reverse the superiority of one management approach compared to the other.