biological niche an organism’s niche describes the full biotic and abiotic conditions in which an...
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Biological Niche• An organism’s Niche describes
the full biotic and abiotic conditions in which an organism lives– Biotic factors:
• Predators• Prey• competition• Vegetation
– Abiotic factors:• Climate• Soil (nutrients)• Terrain
Community Interactions• Interactions of a community:
interactions that affect an ecosystem and drive evolution– Competition - negative effect on both
species • interspecific competition - 2 species
compete for the same resource • Interspecific interactions and adaptation
– drives coevolution and adaptation of species living in close proximity to each other
– exclusion principle states that no 2 species can occupy the same niche
Community Interactions• Predation - benefits one and has
a negative effect on the other – drives evolution - mimicry and
other diverse adaptations – The number and phenotype of the
prey determines the phenotype and number of the predators
Community Interactions
• Symbiosis… “Same Life”– Mutualism - benefits
both equally – Commensalism - one is
benefited while the other is unaffected • very rare in nature
Community Interactions
• Parasitism - parasite benefits while the host is harmed – Parasite obtains most or all of
its nutrition from the host– Can exert a substantial
influence on a population – The parasite generally weakens
but does not kill the host– Disease - similar to parasite
Ecological Succession• Ecological succession refers to
the slow changes in an ecosystem over time– Primary succession• Begins with NO soil
– New islands, bare rock following glacier movement, and volcanic debris are examples
– Lichens (pioneer species) … fungus that breaks down rocks to form soil
Ecological Succession
• Secondary Succession– Process of restoring ecological
balance once soil is present• Following a fire is an example
– Reestablishment of a forest can take up to 300yrs
– The climax community is a representative of the stable ecosystem
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