Energy Flow: Autotrophs Sunlight is the main source of energy for life on Earth. Autotrophs (also known as producers) have chlorophyll that captures the energy that allows a plant to assemble glucose during photosynthesis.

Energy Flow: Autotrophs The best know autotrophs are those that use the power of the sun to create glucose through photosynthesis. The second type of autotrophs use chemical energy to make glucose. This is performed by several types of bacteria. Autotrophs are the foundation of all ecosystems because they make energy available to all other organisms on earth that are not capable of photosynthesis.

Energy Flow: Heterotrophs Heterotrophs: (also known as consumers) consume other organisms for their energy and food.

Types of Heterotrophs Herbivores obtain energy by eating plants. Example: Cow, rabbit, caterpillars Carnivores eat animals. Example: Wolves, lions, owls Omnivores eat both plants and animals. Example: Bears, humans

Types of Heterotrophs Detritivores feed on the remains of dead plants & animals and break the remains down to simple nutrients so that other organisms can consume them. Example: Worms, aquatic insects Decomposers a type of detritivores, they break down dead remains by releasing digestive enzymes Example: Fungi, bacteria

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). Food Chains are a series of steps in which organisms transfer energy by eating or being eaten. Food webs more complex than a food chain, they show interactions within an ecosystem. Feeding Relationships Food Chain

Feeding Relationships Each step in a food chain or web is called a trophic level. Producers make up the first step, consumers make up the higher levels.

Food Chain: Arrows point toward the consumers What is the producer in the food chain? What is the primary (1st) level consumer? What is the secondary (2nd) level consumer? What is the tertiary (3rd) level consumer? What is the quaternary (4th) level consumer?

Food Web Is the frog an herbivore or and omnivore? Is the snake a carnivore or an omnivore? What trophic level is the squirrel? Which carnivore consumes the mouse?

Ecological Pyramids An ecological pyramid is a diagram that shows the relationship amounts of energy or matter contained within each trophic level in a food web or food chain.

Ecological Pyramids Energy Pyramid only 10% of the energy available within one trophic level is transferred to organisms at the next trophic level.

Ecological Pyramids Pyramid of Numbers show the relative number of organisms at each trophic level. As the pyramid moves up the trophic levels the number of organisms decrease because there is less energy available to support the organisms