1. Energy Flow In Ecosystems Notes

2. Producers ▪Sunlight is the main source of energy for life on Earth ▪Organisms that capture energy from sunlight or chemicals and use that energy to produce food are called autotrophs. –They make their own food ▪Also called producers.

3. Producers ▪ Plants use photosynthesis to produce food from the energy they capture from the sun. ▪ Land - best autotrophs are plants ▪ Freshwater - best autotrophs are algae. ▪Some autotrophs produce energy without light –They use a process called chemosynthesis

4. Consumers ▪Many organisms - animals, fungi, and many bacteria - can only acquire energy from other organisms. ▪These animals are called heterotrophs. ▪Also called consumers.

5. 5 Types of consumers

6. Feeding Relationships ▪Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers) 6

7. Food Chains ▪Food Chain: a series of steps in which organisms transfer energy by eating and being eaten. ▪Most ecosystems are complex, too complex to be represented in a food chain.

8. Food Webs –To represent the complex feeding relationship in an ecosystem, food webs are used. –Food webs link all food chains in an ecosystem together.

9. Food Webs ▪Trophic Levels: each step in a food chain or food web. –Producers make up the first level –Consumers make up the second (secondary), third (tertiar y), or higher levels.

10. How Ecosystems Work Video https://www.youtube.com/watch?v=o_RBHfjZsUQ&list=UU1nf2pzxQRKrFUfrUAwp4oA