BIOA02H3 Lecture Notes - Lecture 6: Lichen, Coevolution, Semibalanus Balanoides

• School: UTSC
• Department: Biological Sciences
• Course: BIOA02H3
• Professor: Rachel Sturge

Document Summary

Properties of communities: community: interacting populations of different species found in same place/time, interrelationships govern flow of energy and nutrient cycling within community. Ecological niche: hutchinson (1957), proposed modern niche concept, describes all abiotic components required for an organism to thrive in an area. The realized niches is smaller than the fundamental niche because of competition and other biotic factors. Tadpoles of small frog species may be excluded from some ponds by larger frog species. Biological interactions: feed on nectar from flowers: competition: when individuals use the same resources resulting in lower fitness for both (-/-, two types, intraspecific competition: competition between individuals of the same species. Competitive exclusion: competitive exclusion principle: hypothesis that two or more species cannot co-exist and use single, relatively scares, resource. Predation and community structure: predator mediated coexistence: predation can reduce number of dominant competitors. Leading to coexistence with lesser competitors it would otherwise exclude.