Seed Predator Guilds, Spatial Variation in Post-dispersal Seed Predation and Potential Effects on Plant Demography: a TemperatePerspective

摘要

Although the importance of spatial scale in ecology has long been recognized (e.g. Greig-Smith, 1952), and in the last decade 'multi-scaled analyses' have been increasingly advocated (e.g. O'Neill, 1989; Wiens, 1989; Hoekstra et al, 1991; Levin, 1992;Schneider, 1994; Schupp and Fuentes, 1995), knowledge about the scaling of most ecological processes is still limited. This is particularly true for the interactions between plants and animals that often play a key role in ecosystem dynamics. Scaling matters because it affects the potential for co-evolutionary processes, for example during pollination and seed dispersal (Thompson, 1994). If plant-animal interactions are determined by specific habitat attributes at a local scale with little variation across different landscapes the potential for natural selection might be higher than in a case where the characteristics of the landscape have strong additional effects. The scaling of biotic interactions also has a bearing on species conservation, since interactions which are exclusively determined at the habitat or microhabitat level might be less vulnerable than those which also depend on the overall landscape structure.