The Cycling of Matter & Energy
Ecosystems
Community of interacting organisms within a
biome living in Balance
Each organism
plays a role in
their ecosystem
to maintain
balance
Organisms
Individual living things
Animals
Plants
Bacteria
Fungi
All organisms live in
balance in ecosystems
Food web within an ecosystem
Living organisms in ecosystems are called
biotic
Grouped as:
Producers
Consumers
Decomposers
Make their
own food
Eat other
organisms for
food
Break down
dead material
Producers
Producers make their own
food through
Photosynthesis
by converting sunlight
energy into carbohydrates
which give energy to
consumers
There are three types of consumers:
Primary Consumers
Herbivore-eats only plants
(producers)
Secondary Consumers-carnivore that
eats primary consumers or omnivore that
eats a combination of primary consumers
and producers
Tertiary Consumers
eats only secondary consumers-the
topmost carnivore in an ecosystem
Classify these Critters
Squirrels
Lions
Rabbits
Foxes
Coyotes
Trees
Sheep
Zebras
Deer
Green Algae
Producers
Primary
Consumers
Bobcats
Gophers
Insects
Cows
Owls
Secondary
Tertiary
Grass
Tigers
Consumers
Consumers
Pigs
Flowers
Mice
Cyanobacteria*
Humans*
Are they all easy? Do some fit in
multiple categories?
Energy Flow in Ecosystems
Solar Energy
from the Sun
Primary Consumers
eat Producers for nutrients
and energy
Secondary
Consumers
Producers
eat Primary Consumers for
photosynthesize to make
carbohydrates
nutrients and energy
Tertiary Consumers
Energy
Transfer
Decomposers
eat Secondary Consumers for
nutrients and energy
recycle dead organic waste (biomass)
Energy
Cycling
Energy Flow within an Ecosystem
Heat
Heat
Sun
Heat
Solar
Energy
Chemical
Energy
Chemical
Energy
Primary
Consumer
Producers
Organic
Waste
Heat
Organic
Waste
Secondary/Tertiary
Heat
Consumer
Organic
Waste
Decomposers
Decomposition/Decay
Decomposers
consume dead plants & animals (biomass) to
recycle them back to nutrients for producers
Decomposers are usually put at the bottom of a food web, but they
are very important because they cycle biomass.
Biomass
• Biomass is organic matter left behind when organisms die or as a
byproduct of some industries.
• Decomposers cycle biomass back into the food web by converting
this organic matter into carbon dioxide and nutrients.
• Energy is released in the form of heat during this process.
• Biomass is also considered a renewable energy source!
Nutrients that decomposers recycle
back into the soil:
Water
Nitrogen
Carbon
Phosphorus
These are essential to all life but are only present
in finite amounts throughout the world hence
the need for cycling of nutrients in ecosystems
Decomposers: Bacteria
-Unicellular organisms
-Can break down just about
any type of organic matter
-Live on land, air and sea
-1 gram of soil (about a
paperclip’s weight) contains
40 million (40,000,000)
bacterial cells!
Decomposers: Fungi
-Are not plants
-Does include molds
-Fungi release enzymes to
decompose decaying material
-Fungi grow
on hyphae:
unseen strands
beneath the surface
of the material they
are decomposing
Fungi in action!
Mold growth over a decaying peach
&
Life of Fungi
Decomposers:
Earthworms
• Earthworms act as scavengers
• Earthworms breathe through
their skin
• They do not have eyes but do
have light & touch sensitive
organs
• Earthworms are
hermaphroditic which means
they have both male and
female organs
Composting
Controlled Decomposition – in your backyard!
Humus
Mature compost ready to deliver
the nutrients from decomposed
materials back to producers.
Composting requires a mixture of –
1. Browns – carbon source
3. Water
leaves,
branches
2. Greens – nitrogen source
grass,
food scraps
4. Air
Why Compost?
Think of different reasons that the composting
cycle is important to YOU!
Why Compost?
Turn dead organic waste (biomass), like dead
leaves and table scraps, into a healthy, natural
fertilizer for your gardens and lawns.
The humus can replenish nutrients in the soil.
Results:
• Higher crop yields
• Enrich soil
• Cleaner soil & air
• Suppress plant diseases
• Reduce waste without a
landfill!
The Big Picture:
Cycle of
Matter
Replenish
Soil
Compost
Cycling of
Nutrients
Organic
Waste
Decomposers