Energy Flow in Ecosystems Everything that organisms do in ecosystems (running, breathing, burrowing, growing) all require energy. So, How do they get it?
Primary Energy Source Most of life on earth depends on photosynthetic organisms. How do photosynthetic organisms obtain energy? • Capture sunlight and store it as chemical energy in organic molecules. What are examples of photosynthetic organisms? • Plants, some bacteria and algae.
The rate in which organic material is produced in an ecosystem is called Primary productivity Primary productivity- determines the amount of energy available in an ecosystem. • Which can flow through organisms like a chain reaction.
Sow How does it work? • Producers-are organisms that first capture the energy. Why? • Make energy storing molecules • Consumers-are organisms that must consume plants or other organisms Why? • to obtain the energy necessary to build their molecules
But wait, energy moves? • Ecologist study how energy moves through an ecosystem. • Organisms are given a specific level called a Trophic Level. • The source determines the level and energy can move from one level to the next.
FOOD CHAIN!!!!! • Is the path of energy through the trophic levels Levels 1st- occupied by producers 2nd- are herbivores, animals that eat plants or other primary producers 3rd- are secondary consumers, carnivores-animals that eat other animals
Other groups of animals • Omnivores-animals that are both herbivores and carnivores • Decomposers-they cause decay, bacteria and fungus, creating nutrients recycled through other animals.
Food chain • Shows 1 path of energy flow
Food web • Most ecosystems do not follow simple straight paths because some animals feed at several trophic levels • This creates a complicated, interconnected group of food chains Constructing a food web