摘要：In spite of numerous habitat restoration programs in fresh waters with an aggregate annualfunding of millions of dollars, many populations of Pacific salmon remain significantly imperiled. Habitatrestoration strategies that address limited environmental attributes and partial salmon life-historyrequirements or approaches that attempt to force aquatic habitat to conform to idealized but ecologicallyunsustainable conditions may partly explain this lack of response. Natural watershed processes generatehighly variable environmental conditions and population responses, i.e., multiple life histories, that areoften not considered in restoration. Examples from several locations underscore the importance of naturalvariability to the resilience of Pacific salmon. The implication is that habitat restoration efforts will be morelikely to foster salmon resilience if they consider processes that generate and maintain natural variabilityin fresh water. We identify three specific criteria for management based on natural variability: the capacityof aquatic habitat to recover from disturbance, a range of habitats distributed across stream networks throughtime sufficient to fulfill the requirements of diverse salmon life histories, and ecological connectivity. Inlight of these considerations, we discuss current threats to habitat resilience and describe how regulatoryand restoration approaches can be modified to better incorporate natural variability
