Download Unit 2: Interactions in Ecosystems

Unit 2: Interactions in Ecosystems
Chapter 4: Ecosystems
Lesson 4.1
T.O.C:
What are Ecosystems?
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.
http://www.youtube.com/watch?v=nQO5x8Q3e8g
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
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–
–
–
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
http://www.youtube.com/watch?v=GUY_-LK_lOc
http://www.youtube.com/watch?v=Cf3inHpNXlM
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.
4.1 Review Q’s
1. Why are climate and location the two most
important factors in determining ecosystem
diversity? (2 points)
2. What is an organisms niche? (2 points)
3. How are population & community related in
an ecosystem? (2 points)
4. What are the biotic and abiotic parts of an
ecosystem? (2 points)
5. What is an ecosystem? Give an example of at
least one.