What makes up an ecosystem?  Biotic factors  Plants  Animals  Bacteria  Etc.  Abiotic factors  Water  Light  Temperature  Soil

What factors can determine population size?  Limiting factors are things that can limit the growth of a population  Ex/ amount of space, food and water, predators, competition  (See picture on page 319)

Energy flow in an ecosystem All energy comes from the SUN!! Producers – carry out photosynthesis, trapping the sun’s energy to make food Consumers – feed on other organisms

Food Chains and Food Webs..  Food chains show a series of events where energy flows through an ecosystem  Food webs show all of the possible ways energy can flow through an ecosystem (links all the food chains)

Energy Pyramids..  Show the amount of energy that moves from one feeding level to another in a food web  The most energy is available at the producer level  As you move up the pyramid, each level has less energy available