Energy Flow in Ecosystems WARM UP What is a producer? What is a consumer?

Energy Roles An organism’s energy role is determined by how it obtains energy and how it interacts with other organisms. Each of the organisms in an ecosystem fills the energy role of producer, consumer, or decomposer.

Niche A niche is the role or “job” of an organism or species in its environment. What would be a bee’s niche?

Producers Energy enters most ecosystems as sunlight. Some organisms, such as plants, algae, and some bacteria, capture the energy of sunlight and store it as food energy. (Through photosynthesis) An organism that can make its own food is a producer. Energy is transferred to

Consumers Some members of an ecosystem cannot make their own food. An organism that obtains energy by feeding on other organisms is a consumer.

Consumers Consumers are classified (grouped) by what they eat. Herbivores Carnivores Omnivores Scavengers

Consumers - Herbivores Consumers that eat only plants are herbivores. Examples: caterpillars and deer

Consumers - Carnivores Consumers that eat only animals are carnivores. Examples: Lions and spiders

Consumers - Omnivores Consumers that eat both plants and animals are omnivores. Crows, bears, and most humans are omnivores.

Consumers - Scavengers Some carnivores are scavengers. A scavenger is a carnivore that feeds on the bodies of dead organisms. Examples: catfish and vultures http://www.fisheriesmanagement.co.uk/catfish/catfish_introduction.htm

Decomposers Decomposers break down wastes and dead organisms and return the raw materials to the ecosystem. You can think of decomposers as nature’s recyclers. Mushrooms and bacteria are common decomposers.

Energy Flow In Ecosystems Important Questions Energy Flow In Ecosystems Give an example of a producer. Give an example of a consumer. What are the 4 kinds of consumers? Give an example of a decomposer. What do food chains show? What does a food chain always begin with? What’s the difference between a food chain and a food web? What does an energy pyramid show? Summary

A Typical Food Chain

Food Chains and Food Webs Energy enters most ecosystems as sunlight and is converted into food molecules by producers. This energy is transferred to each organism that eats a producer, and then to other organisms that feed on these consumers. The movement of energy through an ecosystem can be shown in diagrams called food chains and food webs.

Food Chains Every living thing needs energy in order to live. Every time animals do something (run, jump) they use energy to do so. Energy is necessary for living beings to live and grow. Animals get energy from the food they eat, and all living things get energy from food. Plants use sunlight, water and nutrients to get energy (photosynthesis).

Food Chains A food chain shows how each living thing gets food, and how nutrients and energy are passed from creature to creature. Food chains begin with plant-life, and end with animal-life. Some animals eat plants, some animals eat other animals. http://www.sheppardsoftware.com/content/animals/kidscorner/foodchain/decomposers.htm

There is actually even more to this chain. After a hawk dies, fungi (like mushrooms) and other decomposers break down the dead hawk, and turn the remains of the hawk into nutrients, which are released into the soil. The nutrients (plus sun and water) then cause the grass to grow. It's a full circle of life and energy!!

Food Webs A food web consists of the many overlapping food chains in an ecosystem. A food web is more realistic accurate than a food chain.

Which is more stable? A food web is more stable than a food chain.

A Typical Food Web Comprised of several food chains

Energy Pyramids An energy pyramid shows the amount of energy that moves from one feeding level to another in a food web. Where is the most energy available? Why does less energy become available at each level?

How the numbers work in an Energy Pyramid

Try These… Pick an ecosystem (any one you want), and list as many abiotic and biotic factors as you can. Draw a food web within that ecosystem that includes at least four trophic levels and six different organisms. Label the levels and energy roles of each organism. If there is 10,000kcal of energy available at the producer level, how many kcal would be available to an apex predator? Remove one organism from your food web and explain the effect that this would have on the rest of the organisms.