Energy flow through an ecosystem

1. Energy flow through an ecosystem Food Chains, Food Webs, & Energy Pyramids

2. What is in an Ecosystem? • Ecosystems include all the living and nonliving things in a particular area. • Autotrophs/producers make their own food from suns energy • Heterotrophs/consumers gain energy form eating producers or other consumers.

3. Law of Conservation of Energy • The Law of Conservation of Energy states that energy can not be created or destroyed, only transformed from one form (light E) to another (chemical E, in bonds of molecules). • Earth is an open system when it comes to Energy, because of the Sun.

4. Movement of Energy • Once Energy enters the ecosystem (photo) it is passed by eating and/or decomposition. • Autotrophs provide ALL the Energy heterotrophs use!

5. Movement of Energy • When a consumer eats something, only 10% of that organisms Energy is transferred into the consumer. • The other 90% is lost as heat • This transfer of energy is an inefficient process. Most (90%) of the Energy is converted into heat and lost back into space.

6. Trophic Levels • TL1 = Producers = Plants • TL2 = Primary Consumers = Herbivores • TL3 = Secondary Consumers = Omnivores • TL4 = Tertiary Consumers = Carnivores • Decomposers = Break down organic matter and return nutrients to the soil. (bacteria, worms, maggots, mushrooms) • Detritivores = scavengers (crabs, vultures, raccoon)

7. Ecosystem Organization • Food Chain = shows how energy is transferred from one organism to another…eating. • Food Web = shows many feeding relationships that are possible in an ecosystem. • Ecological Pyramids = is a graphical representation of a food chain in which we can look at Energy, Biomass, or organism number.

8. Ecological Pyramids • Pyramid of Numbers look just at the number of organisms at each trophic level. • Pyramid of Biomass look at the amount of living mass in a given area.

9. Ecological Pyramids • Pyramid of Energy = the amount of Energy (calories) with in a trophic level.

10. Calculating Energy Transfer 1. According to Model 1, how many grams of grass does herbivore A eat each day? 2. Refer to Model 1. a. How much did herbivore A grow from eating this grass? b. What term is used to represent growth in Model 1? 3. What is meant by “egested waste” as it is used in Model 1? 4. Is all of the mass of the ingested grass accounted for in the growth and waste of herbivore A? If not, how much is “missing”? Show a mathematical calculation to support your answer.