Ecology & Energy Flow

1. Ecology & Energy Flow Unit 2: “Live and Let Die” Ecology Chapters 3-6

2. Ecology • Ecology—the study ofinteractions among organisms and between organisms and their environment. • The biosphere is the part of Earth in which life exists, including land, air, water, or atmosphere.

3. Abiotic vs. Biotic • Biotic Factors — living things within an ecosystem • Abiotic Factors — nonliving things within an ecosystem

4. Levels of Organization To understand relationships within the biosphere, ecologists ask questions about events and organisms that range in complexity from a single individual to the entire biosphere.

5. Levels of Organization • Species—a group of similar organisms that can breed and produce fertile offspring. • Populations—groups of individuals that belong to the same species and live in the same area. • Communities—assemblage of different populationsthat live together in a defined area.

6. Levels of Organization • Ecosystem—a collection of all the organisms (biotic factors) that live in a particular place, together with their physical environment (abiotic factors). • Biome—a group of ecosystems that have the same climate and similar dominant communities.

7. Energy Flow • Living systems cannot function without constant energy. • Energy flows through an ecosystem in one direction. • Sunlight is the main energy source for life.

8. Energy Flow • Energy from the sun is utilized through photosynthesis. • Some organisms rely on other energy sources, such as energy stored in inorganic molecules. • Energy from chemical sources is utilized through chemosynthesis.

9. Producers and Consumers • Producers—produce food in the ecosystem. These organisms are also called autotrophs, meaning they make their own food. • Consumers—consume food in the ecosystem. These organisms are also called heterotrophs, meaning they rely on other food sources (don’t make food).

10. Types of Consumers • Herbivores—plant eaters • Carnivores—flesh (meat) eaters • Omnivores—eat both plants and meat • Detritivores—detritus (organic particles) eaters • Decomposers—break down (decompose) organic material

11. Food Chains, Food Webs, and Trophic Levels • Food chains show the one way flow of energy in an ecosystem. • Food webs link all the food chains in an ecosystem together. • Each step in a food chain or food web is called a trophic level.

12. Limiting Nutrients • If a nutrient is in short supply, it will limit an organism’s growth. • Limiting nutrient = a single scarce nutrient that is needed in an ecosystem