Metapopulations and salmonids: a synthesis of life history patterns and empirical observations

Metapopulation theory has attracted considerable interest USA with reference to the salmonids. There has been little empirical evidence, however, to guide the evaluation or application of metapopulation con- cepts. From knowledge of salmonid life histories and our own work with bull trout (Salvelinus confluentus), Lahontan cutthroat trout (Onco- rhynchus clarki henshawi) and westslope cutthroat trout (Oncorhynchus clarki lewisi), we suggest that simple generalizations of salmonid metapop- ulations are inappropriate. Although spatial structuring and dispersal mechanisms are evident, the relevance of extinction and colonization pro- cesses are likely to vary with life history, species, scale, and landscape. Understanding dispersal, the role of suitable but unoccupied habitats, and Key words: salmonid; metapopulation; life history; dispersal; persistence; fragmentation the potential for extinction debts in non-equilibrium metapopulations are key issues. With regard to conservation of salmonids, we suggest that B. E. Rieman, U.S. Forest Service, Rocky efforts to understand and conserve key processes likely to influence the Mountain Research Station 316 E. Myrtle,