Warm Up #7 How can you describe an ecosystem?

Interactions Within Ecosystems Lesson 1: Ecosystems

Essential Questions How can you describe an ecosystem? In what ways do living organisms interact? How do population changes affect ecosystems?

Abiotic and Biotic Factors Ecosystems contain all the nonliving and living parts of the environment in the area BrainPOP - Ecosystem Abiotic – nonliving parts of an ecosystem Ex: sunlight, water, soil, air Biotic – living or once-living parts of an ecosystem Ex: trees, ,decaying remains, waste produces, animals

What abiotic and biotic factors can you identify? ACTIVITY

Habitats, Populations, and Communities Habitat – the place within an ecosystem that provides the biotic and abiotic factors an organism needs to survive and reproduce Population – all the organisms of the same species that live in the same area at the same time Community – all the populations living in an ecosystem at the same time

Habitats, Populations, and Communities How do populations and communities compare and contrast?

Interactions of Living Things Niche – the way a species interacts with abiotic and biotic factors to obtain food, find shelter, and fulfill other needs Predation – the act of 1 organism (predator) feeding on another organism (prey) Symbiosis – a close, long-term relationship between 2 or more species that usually involves an exchange of food or energy Competition – interactions between 2 or more organisms that need the same resource at the same time

Symbiosis Mutualism – both species benefit from the relationship Commensalism – 1 species benefits from the relationship and the other isn’t harmed or helped Parasitism – 1 species (parasite) benefits and the other (host) is harmed

Population Changes Populations increase when offspring are produced or new individuals move into a community Populations decrease when individuals die or more away Population density – the size a population compared to the amount of space available High = individuals live closer together Low = individuals live further apart

Population Changes Carrying capacity – largest number of individuals of 1 species that an ecosystem can support over time Depends on abiotic and biotic factors What happens if a population exceeds its carrying capacity? Extinction of 1 population can affect other populations

Population Changes Interpret the graph What information is being presented? What units are being used in the graph? What happens to the moose population as the wolf population increases? What is the maximum population size for the wolves and moose?