Scale of Dispersal in Varying Environments and its Implications for Life Histories of Marine Invertebrates

Summary. We present several models concerning the short term consequences of spreading offspring in varying environments. Our goal is to determine what patterns of spatial and temporal variation yield an advantage to increasing scale of dispersal. Of necessity, the models are somewhat artificial but we feel they are a reasonable approximation f and hence generalizable to natural systems. With these models we examine consequences of dispersal arising from environmental variation: increased en-vironmental variance, different degrees of spatial and temporal correlation, some arbitrary spatial patterns of favorability and finally some patterns derived from long-term, large-scale weather data collected along a contiguous stretch of coastline from south-ern Oregon to northern Washington (USA). We examine the costs and benefits of increasing scale of dispersal in both density dependent and density independent models