Principles of Ecology

Types of Organisms: REVIEW! Autotrophs (Producers) Photoautotrophs Chemoautotrophs Heterotrophs (Consumers) Herbivores Carnivores Omnivores Scavengers Decomposers

Types of Organisms: Autotrophs Also called Producers Organisms that produce their own food from the sun or from chemicals

Types of Organisms: Autotrophs Photoautotrophs Use photosynthesis to make food Ex. plants, algae, certain bacteria

Types of Organisms: Autotrophs Chemoautotrophs Make food from chemicals (chemosynthesis)

Autotrophs

Types of Organisms: Heterotrophs Also called consumers Organisms that make energy from the food they eat

Herbivores - eat only plants Examples: cow, deer

Carnivores – eat only meat Example: Snakes Owls Lions

Omnivores – eat both plants and meat Examples: humans, bears

Scavengers – eat dead matter Examples: vultures, crabs

Decomposers – break down organic matter Examples: bacteria, fungi, earthworms

Energy Flow Through Ecosystems All the energy of life ultimately comes from the SUN! Energy flows through an ecosystem in one direction: SUN  Producers  Consumers

Energy Flow Through Ecosystems Producers (autotrophs) capture the sun’s energy to make food This energy is passed to consumers (heterotrophs) when they eat the producers Energy flow is represented by food chains and food webs

Food chain: a series or steps in which organisms transfer energy by eating and being eaten Reminder: Energy moves from autotrophs to heterotrophs to decomposers (eventually)

Food Web Food web: shows complex relationships between organisms Food webs are more realistic than food chains… Each step in a food chain or food web is called a trophic level

TROPHIC LEVELS Producer Primary consumer Secondary consumer Tertiary consumer Decomposer

Ecological Pyramids and Trophic Levels Each trophic level depends on the one before it for energy.

Therefore, only 10% of the energy is transferred between levels Organisms use much of the energy they produce/consume for life processes such as reproduction, movement, and respiration Therefore, only 10% of the energy is transferred between levels

The 10% rule… AMOUNT OF ENERGY FROM ONE TROPHIC LEVEL TO THE NEXT… PRODUCER PRIMARY SECONDARY CONSUMER CONSUMER

The amount of energy available in an ecosystem can be represented by an ecological pyramid Higher trophic levels are on top of one another in the pyramid

Ecological pyramids can illustrate Energy…..

Ecological pyramids can illustrate Numbers….(how many are there?)

Ecological pyramids can illustrate Biomass (total weight of living matter)