Trophic structure, available resources and population density in terrestrial vs. aquatic ecosystems

摘要: Abstract The relationship between available resources and the level at which density is regulated may not be obvious where direct inter- or intraspecific competition for absent. Interpretation of such cases requires that a distinction made organisms ingesting living material (biophages) those subsisting on dead organic matter (saprophages). A modified trophic model incorporating this used to develop hypothesis explaining how mean densities first-order biophagus are determined in accordance with life history characteristics autotrophs system. Mean biophage will held low levels effects escape from control would most damaging system, i.e. biotic potential biophages much higher than autotrophs. accounts regulatory mechanisms differing helps explain prevalance well-developed three-level communities terrestrial ecosystems four-level aquatic systems.