What Shapes an Ecosystem Biotic and Abiotic Factors
What Shapes an Ecosystem?
Biotic and Abiotic Factors • Ecosystems are influenced by a combination of biological (biotic) and physical (abiotic) factors. • Abiotic factors include: • temperature • precipitation • humidity • wind • nutrient availability • soil type • sunlight
The Niche • The area where an organism lives is called its habitat • A niche is the full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions • No two organisms may occupy the same niche
Community Interactions - Competition • Competition occurs when organisms of the same or different species attempt to use a resource in the same place at the same time
Competitive Exclusion Principle • No two organisms can occupy the same niche in the same habitat at the same time
Predation • An interaction in which one organism (predator) feeds on another organism (prey) • Predator and prey can have huge effects on ecosystems (trophic cascades), but also the evolution of each other
Symbiosis • Any relationship n which two species live closely together • Symbiosis = “living together” • Three main types: – Mutualism – Commensalism – Parasitism
Mutualism • Both species benefit
Commensalism • One benefits, the other is not harmed
Parasitism • One organism lives in or on another organism causing some degree of harm
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