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Species, Interactions, Succession, and Niche. How do it all fit together?. Species . A group of organisms genetically similar enough to have viable (fertile) offspring. Breeding within the species = Intraspecific breeding and results in offspring of that species.
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Species, Interactions, Succession, and Niche How do it all fit together?
Species • A group of organisms genetically similar enough to have viable (fertile) offspring. • Breeding within the species = Intraspecific breeding and results in offspring of that species. • Breeding between differing species = Interspecific breeding and results in a hybrid. • Hybrids are almost always sterile.
Generalists vs. Specialists • Generalists live in many types of places, eat a variety of foods, and tolerate a wide range of environmental conditions. • Specialists typically live in only one type of habitat, eat a limited variety of foods, and tolerate a narrow range of environmental conditions.
Indicator and Keystone Species • Indicator species serve as “early warning systems” for ecosystem damage. (Canary in a coal mine) • Keystone species have a role in an ecosystem that is larger than their abundance or biomass would suggest.
Interactions • Interspecific Competition – two or more species compete for food, space, water, or any other limited resources. • Predation – members of one species (predator) feed directly on all or part of an organism of a differing species (prey).
Interactions (continued) • Interference Competition – one species limits another species access to resources, regardless of their abundance. • Exploitation Competition – one species is able to exploit resource more quickly or efficiently. • Competitive Exclusion – one species eliminates another from an area through competition for limited resources.
Symbiotic Relationships • Long-lasting relationships in which organisms live together in a more-or-less intimate association. • Mutualism – both organisms benefit. (+,+) • Commensalism – one organisms benefits and other is (seemingly) unaffected. (+,o) • Parasitism – one organism (parasite) feeds on another organism (host) for a significant portion of the host’s life. (+,-)
Ecological Succession • Primary Succession – development of a biotic community from an essentially lifeless area where no soil or bottom sediment exists. • Pioneer species • Early successional plants • Midsuccessional plants • Late successional plants • Climax community
Ecological Succession (cont.) • Secondary Succession – occurs where intact, natural vegetation has been disturbed, removed, or destroyed.
Ecological Niche • Fundamental Niche – the full potential range of resources an organism could use if no competition were present. • Realized Niche – what an organism is able to achieve given the competition that exists. • Limiting Factors – those factors which keep an organism from realizing its fundamental niche.
Homework • Answer questions 1 and 2 on page 154 of your textbook. • Due Monday, October 3, 2011.