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Ecology Part II: Ecosystems & Communities. Chapters 24.3, 25.3, 26.1. What Makes Up an Ecosystem?. Biotic Factors : living or once-living environmental features in an ecosystem. Abiotic Factors: non-living physical features. How Do Organisms Interact in an Ecosystem?.
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Ecology Part II:Ecosystems & Communities Chapters 24.3, 25.3, 26.1
What Makes Up an Ecosystem? • Biotic Factors: living or once-living environmental features in an ecosystem. • Abiotic Factors: non-living physical features.
How Do Organisms Interact in an Ecosystem? • Predator/Prey Interactions • Predator: consumer that captures and eats other consumers • Prey: organism that is captured and eaten by predator
What is Symbiosis? • Symbiosis: any close relationship between species. • Mutualism: relationship where both species benefit • Commensalism: one species benefits and one is unaffected
What is Symbiosis? (cont.) • Parasitism: relationship in which one organism benefits (the parasite) and the other is harmed (the host)
How do Organisms Produce Food? • Producers: organisms that use an outside energy source to produce their own food • Energy from the sun is captured by plants, algae, or bacteria through photosynthesis. • Energy from chemicals is captured by some bacteria through chemosynthesis.
How do Organisms Consume Food? • Consumers: organisms that obtain energy by eating other organisms. • Herbivores: eat plants (deer and rabbits) • Carnivores: eat animals (frogs and lions) • Omnivores: eat both plants and animals (pigs and humans) • Decomposers: eat dead organisms
What is a Food Chain? • Food Chain: a model of the feeding relationships in an ecosystem.
What is a Food Web? • A food web shows all the possible feeding relationships among the organisms in a community.
How Does Energy Move Through an Ecosystem? • An energy pyramid shows the amount of energy available at each feeding level in an ecosystem.
What is an Ecological Disturbance? • Disturbances can change ecosystems, communities, and populations. • Examples: forest fires, floods, human influences • Permanent changes to an ecosystem leads to ecological succession: normal, gradual changes that occur in the types of species that live in an area.
What are the Types of Succession? • Primary Succession: begins in a place without soil. • Example: an ecosystem beginning on bare rock
What are the Types of Succession? • Secondary Succession: begins in a place that has soil and once had living organisms • Example: after fire or removal of buildings • Pioneer species: the first species in an ecosystem. • Example: lichens
What are Invasive Species? • Nonnative organisms that spread widely in a community • A lack of limiting factors such as predators, parasites, or competitors enables their population to grow out of control. • Not all invasive species are harmful. Did You Know?Although the European honeybee is invasive to North America, it is beneficial because it pollinates our agricultural crops.