Principles of EcologyPrinciples of Ecology

Types of Organisms: REVIEW!• Autotrophs (Producers)

– Photoautotrophs

– Chemoautotrophs

• Heterotrophs (Consumers)– Herbivores

– Carnivores

– Omnivores

– Scavengers

– Decomposers

Types of Organisms: Autotrophs

• 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

• Heterotrophs–Also called consumers–Organisms that make energy from the food they eat

Types of Organisms: Heterotrophs

Herbivores- eat onlyplants

Examples:cow, deer

Carnivores – eat only meat

Example:SnakesOwlsLions

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

1.Producer2.Primary consumer3.Secondary consumer4.Tertiary consumer5.Decomposer

Ecological Pyramids and Trophic Levels

• Each trophic level depends on the one before it for energy.

• 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…

PRODUCER PRIMARY SECONDARY

CONSUMER CONSUMER

AMOUNT OF ENERGY FROM ONE TROPHIC LEVEL TO THE NEXT…

• 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)