Different physical and biological processes＇ prevail at different scales(1-4). As a consequence, small-scale experiments or local observations provide limited insights into regional or global phenomena(5-8). One solution is to incorporate spatial scale explicitly into the experimental and sampling design of field studies, to provide a broader, landscape view of ecology(1-8). Here we examine spatial patterns in corals on the Great Barrier Reef, across a spectrum of scales ranging from metres to more than 1,700 km. Our study is unusual because we explore large-scale patterns of a process (recruitment by juveniles) as well as patterns of adult abundance, revealing the relationship between the two. We show that coral-reef assemblages that are similar in terms of abundance may nonetheless show profound differences in dynamics and turnover, with major implications for their ecology, evolution and management.