Ecology

1. Ecology Symbiotic Relationships

2. Competition • Species living in the same habitat may use the same resources. • These species will compete for the resource.

3. Predation • A relationship between two species • Predator: captures and feeds on the other organism • Prey: is the one that gets eaten. • In ecology this relationship is a form of population control. • If there are not enough predators, too many prey will exist, and vice versa

4. Symbiosis • Any relationship in which two organisms live closely together • Means “living together” • Three main classes of symbiotic relationships

5. Parasitism • In a parasitic relationship one organism lives in or on another organism(the host) and harms it • The parasite gets its nutritional requirements from the host • The host is weakened, but usually does not die

6. Parasitism

7. Mutualism • Both organisms benefit from the relationship.

8. Mutualism

9. Commensalism • One organism benefits from the relationship while the other organism neither benefits nor is harmed

10. Commensalism

11. Ecology Food chains and food webs

12. Trophic Levels A trophic level is one of the steps in a food chain or pyramid

13. Level One This level is always the producers Producers are organisms that first capture energy Aka: autotrophs Ex: plants, algae, some bacteria

14. Consumers • An organism that consumes plants or other organisms to obtain energy • Consumers make up the rest of the trophic levels • Aka heterotrophs

15. Level Two This level consists of herbivores-organisms that eat plants Consumers on this level are called primary consumers

16. Level Three This level consists of carnivores- organisms that eat other organisms for energy They are called secondary consumers

17. Level Four Consumers on this level are called tertiary consumers They are carnivores who eat other carnivores

18. Other organisms in a food web • Detritivores-an organism that feeds on organic waste • Omnivores- organisms that eat both plants and other organisms • Decomposers- An organism who recycles nutrients by feeding on dead or decaying organisms. Decomposer Detritivore Omnivore

19. What is the difference between a Detritivore and a Decomposer? • They both obtain energy from organic matter (dead/decaying plants and animals), but… • The way they consume the organic matter is different • Detritivores actually eat the organic matter • Decomposers secrete enzymes that break down the organic matter into small molecules and then consume those small molecules

20. Food Chain • A path of energy through the trophic levels of an ecosystem

21. Food web • A diagram that shows the feeding relationships between organisms in an ecosystem

22. Question: • How are food chains and food webs related? • Several food chains make up a food web

23. Types of Food Webs • Grazing food web: starts with plants in the first trophic level • Plants get their energy from the sun • Detritus food web: starts with dead organic matter such as plants or animals

24. Energy Loss • As you go up each trophic level energy is lost • Most energy is lost to the environment as heat • An organism stores about 1/10 of the energy stored by an organism in the level below it

25. Energy Loss 0.2 2 20 The first trophic level starts with 100% energy. 200 X .01 (10%)

26. Pyramid of Biomass • The decrease in energy going to up in levels means that there is less energy for animals to survive on. • Less energy means less animals. • This is referred to as a decrease in biomass