Minimum dynamic reserves: A framework for determining reserve size in ecosystems structured by large disturbances

摘要

We introduce minimum dynamic reserves: a framework for the minimum reserve size required to incorporate natural disturbance and maintain ecological processes. The minimum dynamic reserve framework is a refinement of the minimum dynamic area concept, relating the size of the dominant disturbance on a landscape to communities of species that may be differentially affected by this disturbance. We present criteria for estimating the size, location, and efficacy of a minimum dynamic reserve and then apply our approach to identify a candidate minimum dynamic reserve in the Mackenzie Valley region of Canada. In this region, forest fire is the major natural disturbance that influences vegetation community dynamics and dependent fauna. The size and location of a minimum dynamic reserve is determined by the estimated maximum extent of the largest disturbance event and the extent and distribution of communities of species that are differentially affected by disturbance. A minimum dynamic reserve is deemed effective if it maintains internal recolonization sources through time. We designed and evaluated our candidate minimum dynamic reserve using a spatially explicit, dynamic simulation model, CONSERV, that incorporates locally calibrated fire and vegetation dynamics. During simulations, our candidate minimum dynamic reserve maintained its recolonization sources through time, suggesting that minimum dynamic reserves may provide an operational framework for determining reserve size in dynamic landscapes under the influence of large natural disturbances such as fire, insect outbreaks, windstorms and flooding.