ENV200H1 Lecture Notes - Lecture 1: Ecotone, Biome, Water Cycle
Document Summary
Life on earth is organized into interconnected systems arranged in levels of organization (hierarchies) (cid:149) abiotic + biotic (cid:149) hierarchy: ecosystem community population individuals. Basic characteristic of ecosystem (cid:149) structure: non-living: physical-chemical, living: ecological community set of species interacting within ecosystem (cid:149) process, cycling of chemical elements. 5 cycles: energy/ water/ carbon/ nitrogen/ phosphorus: flow of energy (cid:149) change succession. Different individuals thriving under different environmental regimes (cid:149) the optimum represents the conditions favored by the majority of organisms in the population: optimum = maximum, do the best (highest number/ density) At higher or lower levels, individuals are under stress with only some capable of persisting: larger than optimum = less well, under stress. Beyond the limit of tolerance, no individuals can survive, hence the species will not be found in these kinds of environments: at extreme = poor, cannot tolerate. Some organisms have generally wide ranges of tolerance (generalists). Generalists can live in a variety of habitats.