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ECOSYSTEMS. Key Concepts . How do biotic & abiotic factors influence an ecosystem? What interactions occur within communities? What is ecological succession?. Abiotic vs. biotic. The biological influences on organisms within an ecosystem are called biotic factors.
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Key Concepts • How do biotic & abiotic factors influence an ecosystem? • What interactions occur within communities? • What is ecological succession?
Abiotic vs. biotic • The biological influences on organisms within an ecosystem are called biotic factors. • Plants, bacteria, animals (living factors) • Physical or non-living factors that shape ecosystems are abiotic factors. • Precipitation, humidity, sunlight, etc. • Together, biotic and abiotic fact determine the survival & growth of an organism.
Abiotic vs. biotic (cont.) • An area where an organism lives is called a habitat. • A habitat includes both abiotic and biotic factors.
Niche • A niche is the full range of physical and biological conditions in which an organism lives. • Includes the type of food, how its obtained, and what species eat the food. • Also includes how and when it reproduces. • No two species can share the same niche in the same habitat. • Habitat vs. niche
Community Interactions • Competition, predation, and various forms of symbiosis affect an ecosystem. • Predation – an interaction in which an organism captures and feeds on another organism. • Predator and prey
Community Interactions • Symbiosis – A relationship in which two species live closely together • “living together” • 3 main classes of a symbiotic relationship • Mutualism • Commensalism • Parasitism
Symbiosis relationships • Mutualism – both species benefit • Insects and flowers • Commensalism – one organism is benefited the other is neither harmed nor helped. • Barnacles on whales • Parasitism – one organism lives and harms another organism. • Tapeworms inside mammals
Ecological Successions • The series of predictable changes that occurs in a community over time is called ecological succession. • Successions that occur on surfaces where no soil exists is called primary succession. • Volcanic eruptions, glaciers, etc. • Pioneer species are first to populate an area • Succession following a disturbance that destroys a community • After wildfires, floods, etc.
Organization in ecosystems • Species: a group of organisms so similar they can breed • Population: groups of individuals belonging to the same species • Communities: assemblies of different populations that live together • Ecosystem: collection of all organisms in a particular place. • Biome: group of ecosystems that have the same climate.