Energy Flow in Ecosystems What is a food

Energy Flow in Ecosystems

What is a food chain? Tertiary Consumer – Eat Secondary Consumers Secondary Consumer – Eat Primary Consumers. Energy Flow 2 nd Consumer Primary Consumer – Eat 1 st Consumer Primary Producers. Energy Flow The order that animals feed on other plants and animals is called a food chain. Energy Flow 3 rd Consumer Producer Primary Producer – Plants, algae, or bacteria that produce their own food by photosynthesis.

What are trophic levels? q Greek (trophē) referring to food or feeding q Position that an organism occupies in a food chain q Can be represented by numbers, starting at level 1 with producers. 4 3 2 1

What is a food web? A food web shows how animals and plants are connected in many ways. Connects many food chains in an ecosystem

Energy Flow Through Ecosystems Heat Loss Energy Flow • The first law of thermodynamics states that energy cannot be created or destroyed; it can only be changed from one form to another. • Light energy is absorbed by plants where it is converted to stored chemical energy. Heat Loss s Los t a e H

Energy Flow Through Ecosystems The second law of thermodynamics states that whenever energy is transformed, there is a loss of energy through the release of heat q When one animal feeds off another, there is a loss of 1 heat (energy) in the process 2 3 q This occurs when energy is transferred between trophic levels through biotic interactions q Additional loss of energy occurs during respiration and movement q q About 90% of energy is lost each time one moves up a trophic level

Energy Flow in an Ecosystem Without a constant input of energy, living things cannot function. q Sunlight is the main source of energy for life on Earth. q Energy flows in one direction from the sun to autotrophs (producers) and then to various heterotrophs (consumers). q The flow of energy through an ecosystem is one of the most important factors that determine the system’s capacity to sustain life. q The flow of energy through an ecosystem starts with the plants and ends as heat loss

Ecological Pyramids 90 % E n sfe an y tr erg s en los 0. 1% Tertiary Consumers % at 10 He 1% Secondary Consumers e r g 10 % Lo Hea ss t d rre 90 % y D e rgy e en red fer ns tra c r e % 10 90 % H Lo eat ss 10% Primary Consumers (herbivores) yt erg en s e s rre sfe ran 100% Primary Producers a d Parasites and decomposers feed at each level Pyramid of Energy Shows the relative amount of energy available at each trophic level Pyramid of Biomass Represents the amount of living organic matter at each trophic level. Pyramid of Numbers Shows the relative number of individual organisms at each trophic level.

In Review: Interdependence… Where Abiotic Meets Biotic! Nutrients cycle through ecosystems, but energy flows and eventually leaves. Energy must be continually supplied to the ecosystem by the Sun.