1. Chapter 37.1 and 37.2 – Ecology Dynamics

2. 37.1 The Flow of Energy  Sun: ultimate source of energy  The flow of energy is one way – from photosynthetic organisms to heterotrophic organisms.  This energy moves through the ecosystem as one organism consumes another for food.

3. The Autotroph Organisms that make their own food Producers - because they make food that is used by the entire community Examples: Algae in a pond, grasses, shrubs, trees on land, phytoplankton in the ocean

4. The Heterotroph An organism that cannot make its own food Consumers - obtains energy and nutrients by ingesting other organisms

5. The Food Chain The pathway for the transfer of energy within an ecosystem Each organism provides food for the next higher organism Food Chains

6. Example of a food chain

7. The transfer of energy Decomposer Tertiary Consumer Secondary Consumer Primary Consumer Producer

8. Transfer of energy Not all energy and matter is transferred: 1- part of the energy is lost (as heat) to the environment 2 - not everything is eaten or used as energy Only 10% is transferred to the next level Therefore, food chains can support no more than 4 or 5 links

9. Trophic Levels: each step in the transfer of energy and matter in an ecological community First Level - Producers: the base of all food chains Second Level - Primary consumers: feed directly on producers Third Level- Secondary consumers: feed directly on primary consumers Fourth Level - Tertiary consumers: feed on secondary consumers

10. More ecology terms: Herbivores- eat only plants Carnivores- only eat meat Omnivores- eat both Scavengers- feed on dead animals Decomposers- feed on wastes and dead organic material (This breaks it down and returns the nutrients to the soil.)

11. Food Webs Food web: demonstrates the interconnectedness of food chains in a community or an ecosystem Fitting Algae Into the Food Web

12. Biological Magnification Build up of a pollutant in organisms at higher trophic levels in a food chain 1940’s DDT (a pesticide)

13. 37.2 Ecological Pyramids Energy: total energy of all the organisms in a food chain or an ecological community Biomass: the total mass Numbers: the total amount of individuals Food Chains