Energy in the Ecosystem OUR PLANET Energy in the Ecosystem I Give Up. What’s black & white and read all over?

How Do Ecosystems Work? The Sun - The source of all energy on Earth* Without the sun, our planet would be cold and dark without anything to eat and fresh water would be scarce! Producers (Autotroph) – Make their own food; Ex: Plants Photosynthesis changes solar energy into chemical energy Without producers there wouldn’t be any food for the… Consumers (Heterotrophs) – Obtain energy from other organisms; Ex: Animals, Fungi and many bacteria Which are these? Consumer Producers ???

Types of Consumers There are four different types of consumers… Why is a vegetarian still considered an omnivore? Types of Consumers Energy Source Examples Herbivore producers cow, pleco Carnivore other consumers snake, vulture Omnivore producers & consumers people, bears Decomposer decaying matter fungi & bacteria

Can Life Exist Without The Sun? *Without the sun, life on earth could still exist due to… Chemotrophs – These deep ocean bacteria get energy from hydrogen sulfide that’s released from volcanic vents These bacteria support entire ecosystems that have never seen the sun! Could life exist on Titan, one of Saturn’s moons, that’s almost 1 billion miles from the sun? Maybe… It would need a volcanic core to keep it’s ocean from freezing.

Storing & Using Energy What does a plant need to survive? Photosynthesis uses Water, Carbon Dioxide and Sunlight to create Sugar (energy stored as glucose) & Oxygen (waste) H2O + CO2 + Energy  C6H12O6 + O2 While plants use photosynthesis to create food (stored energy), plants & animals have another process to use the energy… Cellular Respiration – Plants and animals use Sugar and Oxygen to get energy, releasing water & carbon dioxide C6H12O6 + O2  H2O + CO2 + Energy What do you notice about these equations?

What have you learned so far? Let’s Review… What have you learned so far? 1. Describe how energy from the sun can be used by a wolf. 2. Describe the four different types of consumers. 3. Explain the similarities and differences between photosynthesis and cellular respiration.

How Energy Flows Trophic Level – Each step in which energy and matter are transferred within an ecosystem; Ex: Energy pyramid Most of the energy taken in by an organism at one trophic level is used before that energy can be passed to the next level. Organisms use their energy to complete life’s processes. Which level has the highest population? Which has the lowest population?

An Analogy for Trophic Levels Think of our school population in terms of size : Bottom = students – biggest population Above the students are the teachers Top of the pyramid is smallest population: Administration (Mr. Nichol and the Vice Principals)

How Energy Flows The 10% Law – Only 10% of the energy at each trophic level is passed on to the next and 90% is used or lost. Carnivores are found at the top. And just ~50 Calories from the grass are passed on to the lion. Next are the herbivores. But only ~500 Calories are passed on to the giraffes. At the base of every pyramid are producers. . Make ~5,000 Calories of energy/m2 each year.

A Closer Look At Trophic Levels Food Chain – A specific diagram that shows how energy flows from one organism to another Why did the bald eagle population drop so much in the 1970s? Thin eggs were being crushed by the mom before they could hatch. A look at the food chain showed that DDT, a powerful pesticide, became more concentrated as it moved up each trophic level. In part, due to the damage caused by DDT, bald eagles were on the endangered species list from 1973-2007.

Seeing The Big Picture Food Webs – Shows multiple, interconnected food chains; A more accurate image of how organisms survive in an ecosystem Each year, 1-3 million people are killed by a deadly disease known as… Malaria! It is transmitted, person to person, by the mosquito. Wouldn’t it be great if we could kill all the mosquitoes in the world? How many other creatures would be affected if mosquitoes vanished?

What have you learned in this unit? Let’s Review… What have you learned in this unit? 1. What is a trophic level? 2. Why does an energy pyramid typically only have 4-5 levels? 3. Which types of organisms are found at each level of an energy pyramid? 4. Give an example of when studying a food chain would be important. 5. Give an example of when studying a food web would be important.