ENERGY FLOW AND FEEDING

RELATIONSHIPS

~Ecology Notes~

ENERGY FLOW THROUGH AN ECOSYSTEM

1. Sun

2. Autotrophs

3. Heterotrophs

4. Decomposers

ENERGY IS NOT

RECYCLED!!!!

ALL LIVING THINGS NEED ENERGY The sun is the original source of energy for

most ecosystems.

All organisms in an ecosystem can be divided into one of two groups based on how they get their energy:Autotrophs Heterotrophs

AUTOTROPHSAKA

PRODUCERS

Organisms that make their own food from light or chemical energy.

Include:Plants AlgaeSome bacteria

HETEROTROPHSAKA

CONSUMERS Organisms that eat other organisms to get

the energy they need to survive. Include:

HumansFishMushrooms

WHAT TYPES OF HETEROTROPHS ARE

THERE?

CARNIVORES Organisms that eat only other

animalsEx: Lions and wolves

HERBIVORES Organisms that eat only plants

Ex: Rabbits and cows

OMNIVORES Organisms that eat plants and animals

Ex: People and bears

DETRITIVORES Organisms that feed on small pieces of dead

plants and animals. Ex: worms and roly polies

DECOMPOSERS Organisms that use digestive chemicals to

break down dead organisms Ex: Fungus (mushrooms and mold), and some

bacteria

In order for an ecosystem to survive, there must be a perfect balance of autotrophs, heterotrophs, and decomposers.

A BALANCED ECOSYSTEM

WHY IS EACH GROUP NECESSARY?

The autotrophs make oxygen and food for the heterotrophs.

The heterotrophs produce carbon dioxide for the autotrophs and waste for the decomposers.

The decomposers break down the animal waste and dead organisms and produces carbon dioxide for the autotrophs.

FOOD CHAIN

A simple diagram to show one possible path of energy through an ecosystem.

FOOD WEB A complex diagram that shows all possible paths of energy through an ecosystem.Basically shows how all the food chains in an ecosystem connect to each other.

TROPHIC LEVEL & ENERGY LOSS

Trophic Level = each step in a food chain or food web

Each trophic level depends on the level below it for energyOnly 10% of the energy is passed from one trophic level to the next.

ENERGY PYRAMID

Shows the relative amount of energy being passed from one

trophic level to the next.

WHAT IS BIOMASS? The total amount of living tissue within a trophic level

A biomass pyramid represents the amount of potential food available for each trophic level

BIOMASS PYRAMID As you move up a food chain, there are fewer organisms and less biomass at each level.

Producers are always on the bottom.