Ecology Energy and Food chains

Energy Flow in Ecosystems Organisms require a constant source of energy to survive

Energy flow in Ecosystems Energy flows through an ecosystem in one-direction FIRST LAW of THERMODYNAMICS: Energy can be converted from one form to another, but cannot be created or destroyed. SECOND LAW of THERMODYNAMICS: Transformations of energy always result in some loss or dissipation of energy

Energy Flow contd Ultimate source of energy for all organisms is the sun

Producers An organism that converts sunlight energy into chemical energy Plants are the base of every food chain

Consumers Organisms that cannot make their own energy Herbivore: eats only plants Ex. Cows, horses Carnivore: eats only meat Ex. Polar bear Onmivore: eats plants and animals Ex. Humans, grizzly bears Scavenger: carnivore that eats dead organisms Ex. Vultures, crows Decomposers: organisms that recycle nutrients in dead animals and their wastes Ex. Millipedes, worms, molds, fungus, bacteria

Food Chains The mechanism in which Energy is transferred from one organism to another

Food Chains Starts with a producer and finish with a top carnivore

Examples Deer grazes on grass  energy is transferred from grass to deer

Examples Wolves feed on deer  energy is transferred from deer to wolf

Algae krill cod Leopard Seal  Killer Whale

Food Web - A representation of the feeding relationships within a community - Interconnecting food chains (a more realistic view)