This research level text focuses on the influence of climate variability on the marine ecosystems of the North Atlantic. The ecological impact of climate variability on population dynamics is addressed at the full range of trophic levels, from phytoplankton through zooplankton and fish to marine birds. Climate effects on biodiversity and community structure are also examined. 40 scientists from around the world synthesise what is currently known about how climate affects the ecological systems of the North Atlantic and then place these insights within a broader ecological perspective. Many of...

4.1.1 Demographic significance Confined populations grow more rapidly than populations from which dispersal is permitted (Lidicker, 1975; Krebs, 1979; Tamarin et at., 1984), and demography in island populations where dispersal is restricted differs greatly from nearby mainland populations (Lidicker, 1973; Tamarin, 1977, 1978; Gliwicz, 1980), clearly demonstrating the demographic signi ficance of dispersal. The prevalence of dispersal in rapidly expanding populations is held to be the best evidence for presaturation dispersal. Because dispersal reduces the growth rate of source populations, it...