1. Third lecture

2. Ecosystem An ecosystem is a self-sustaining, dynamic community of plants and animals in relation to their physical environment. System Interacting parts that share common location in space, time and/or function

3. Ecosystem All of the organisms living in a particular place as well as the chemical/physical factors with which they interact. Range in size from small (like aquarium) to large (like forest) E.g. desert ecosystem: organisms that live there (cacti, snakes, rodents), soil chemistry, average rainfall, temperatures etc.

4. Any ecosystem is composed of: 1-Abiotic components (nonliving factors) such as: light, temperature, water, oxygen, minerals, pH and soil. 2-Biotic components (living things) such as: i-Producers (autotrohps): they are the green plants since they produce organic compounds that serve as food.

5. Autotrophs A groups of organisms that can use the energy in sunlight to convert water and carbon dioxide into Glucose (food) Ex. Plants and Algae

6. Autotrophs Chemotrophs –Autotrophs that get their energy from inorganic substances, such as salt –Live deep down in the ocean where there is no sunlight –Ex. Bacteria and Deep Sea Worms

7. ii-Consumers (heterotrophs): Organisms that do not make their own food: Primary consumers (herbivores): Organisms that feed directly on green plants. Secondary consumers: Are carnivores that prey on the primary consumers. Tertiary consumers: Predators on the secondary consumers and primary consumers. detritivores -consumers that get their energy from detritus-nonliving organic material.

8. iii-Decomposers: These organisms decompose organic material in ecosystem and transfer chemical elements in inorganic forms to reservoirs such as soil, water, and air. These chemical elements are cycled, or returned to the environment, where other living things use them again.

9. Consumers (heterotrophs) They consume other organisms in order to live Ex. Rabbits, Deer, Mushrooms

10. Heterotrophs 1.Scavengers/Detritivores: feed on the tissue of dead organisms (both plans and animals). Ex. Vultures, Crows, and Shrimp

11. Heterotrophs 2.Herbivores: eat only plants Ex. Cows, Elephants, Giraffes

12. Heterotrophs 3.Carnivores: eat only meat Ex. Lions, Tigers, Sharks

13. Heterotrophs 4.Omnivores: eat both plants and animals. Ex. Bears and Humans

14. Heterotrophs 5.Decomposers: absorb any dead material and break it down into simple nutrients or fertilizers. Ex. Bacteria and Mushrooms