What Is An Ecosystem

1. What Is An Ecosystem Section One

2. Ecology is the study of the interactions of living things with each other and their environment.

3. The place where a particular population lives is its habitat.

4. The many different species that live together in a habitat are a community.

5. An ecosystem consists of a community and all of the physical aspects of its habitat.

6. The physical aspects of an ecosystem are called abiotic factors

7. The organisms of an ecosystem are biotic factors.

8. The variety of organisms that exist in an ecosystem is called biodiversity. It is very important that ecosystems be diverse to maintain stability.

9. As soil builds in ecosystems and is eroded away, as water channels change, and as weather varies, ecosystems ever so slowly change in a process known as succession.

10. Primary succession is the changing ecosystem that occurs where life has not been before.

11. Succession that occurs where an ecosystem has been before is called secondary succession.

12. The first organisms to appear in succession are called pioneer species.

13. Energy Flow in Ecosystems Section Two

14. The rate at which organic materials (food) is produced in an ecosystem by photosynthesis is called primary productivity.

15. Organisms such as green plants, algae, and some bacteria that capture energy and store it in food are called producers.

16. Consumers are organisms that use producers for food.

17. Energy travels through the ecosystem through various feeding groups known as trophic levels.

18. The lowest or first trophic level is occupied by producers that are capturing energy and building food.

19. The second trophic level is occupied by herbivores that consume producers.

20. The third trophic level is occupied by carnivores which eat herbivores or by omnivores which may feed on plants or animals.

21. Most food chains contain a special level called detritivores or scavengers which feed on dead organisms or living by-products.

22. Bacteria and fungi make up a group known as decomposers which bring about the break down of any tissue back to usable nutrients.

23. Another special group is called top carnivores which may feed on any animal including other carnivores.

24. Most food chains do not following simple paths but become tangled into a network of feeding relationships called a food web.

25. It is important to note that nutrients are cycled in an ecosystem but energy flows through the system and is lost as heat at each level. Each trophic level receives only 10 percent of the energy concentrated by the level below it.

26. Each level that is added to a food chain greatly increased the biomass needed to support it in the levels below it.

27. Some pyramids can show the biomass of each level needed to support it. Wide, flat pyramids represent the most stable ecosystems.