1 Unit 2: Interactions in EcosystemsChapter 4: Ecosystems Lesson 4.1 T.O.C: What are Ecosystems?

2 Ecosystems Ecosystem(w.w)- area where organisms interact w/ one another as well as w/ the nonliving parts of the environment. Ex: pond, river, forest, desert Can be as large as a lake or forest or as small as a mud puddle or rotting log (pillbugs) Ecosystems have both biotic & abiotic parts. Biotic = living parts of ecosystem. Ex: trees, animals, trees Biotic parts interacts w/ one another. Ex: Squirrel/birds & trees These parts help shape the environment. Roots split rock & anchor soil, moles & prairie dogs change the ground shape Abiotic= nonliving parts of ecosystem. Ex: climate, water, air These parts help determine what lives in the ecosystem. Think about the different climates in the world.

3

4 A Place to Live Remember: there are different types of plants & animals in an ecosystem… Population(w.w)- group of organisms of the same species living together in an ecosystem. In a forest you might see a nest of squirrels in a tree, a hive of honeybees, or grove of oak trees. Each are populations Community(w.w)- all the populations living in an ecosystem. The populations of a community interact by using one another for both food & shelter. Habitat(w.w)- part of the ecosystem in which an organism lives. (just like you live in YOUR house, wolves have dens, etc.) The habitat supplies what the organism needs- heat, light, water, food, & shelter 2 pop.s w/ similar needs can share a habitat (owls/hawks) but not a niche Niche(w.w)- an organisms role in an ecosystem. So, everything it needs & everything it does. Includes interaction w/ biotic & abiotic Organisms can have broad niches or narrow niches. Broad= live in a lot of places. Mice, raccoons, mountain lions, wolves, people Narrow= live in one particular habitat. Penguins, polar bears, arctic fox If 2 pop.s in ecosystem have same niche then they must compete for resources

5

6 Diversity Ex: hummingbirds drink nectar from flowers, so they would need flowers for food, feed small spring flies tot heir young, and line their nests w/ the downy leaves of the mullein plant. Therefore, all these must be present in an ecosystem w/ hummingbirds. Diversity(w.w)- variety of species in an ecosystem. Some ecosystems are very diverse while others have just a few different species. Why is this?? There are 2 reasons: Climate & location! In general, ecosystems closer to the equator have more species & so are more diverse. Ecosystems closer to Earth’s poles have fewer species & so they are less diverse. Actions of ppl are making ecosystems less diverse.

7 4.1 Review Q’s Why are climate and location the two most important factors in determining ecosystem diversity? (2 points) What is an organisms niche? (2 points) How are population & community related in an ecosystem? (2 points) What are the biotic and abiotic parts of an ecosystem? (2 points) What is an ecosystem? Give an example of at least one.