Interactions in an Ecosystem

Ecosystem- Two ProcessesSeparate and NOT EQUAL

Energy Flow

Nutrient Cycles

Part 1: Energy Flow

One directional

Energy Enters Atmosphere

(Light)

Energy Exits Atmosphere

(Heat)

Energy Flow

-Light energy

-Heat Energy energy

–Kinetic energy

Energy Flow

• Energy flow begins with light energy

Sun’s Light Energy transformed into chemical energy through

photosynthesis!• Autotrophs (aka Producers) – make

(produce) their own food

6CO2 + 6H2O C6H12O6 + 6O2

(FOOD)

Photosynthesis

• On land – green plants

• Upper levels of ocean water + ponds – algae (photosynthetic protista)

• In salt marshes + tidal flats – photosynthetic bacteria

Sun’s Light Energy Chemical Energy

As the plant grows, some of the energy is used for life processes.

But most of the ENERGY acquired from the sun is LOST

as heat energy.

Green PlantsHerbivores

As the mouse lives, some of the energy is used for life

processes (heart beat, etc.), but most of the ENERGY is

LOST as heat energy.

Herbivores Carnivores

As the fox lives, some of the energy is used for life

processes (heart beat, etc.), but most of the ENERGY is

LOST as heat energy.

All Animals and Plants eventually…DIE

Energy flow

• After death, animals and plants get consumed by decomposers.

Energy Flow

• Nutrients in the dead plants and animals are recycled BUT

• Energy exits the Earth in the form of heat

Deep Ocean Ecosystem, etc.

• A different type of ecosystem exists deep below the ocean waters, volcanic vents + tidal marshes

• This ecosystem depends on Chemosynthesis instead of Photosynthesis for capturing energy*.

Ecological Pyramid showing Energy Loss at each Level

Trophic level 1

Trophic level 3

Trophic level 2

Trophic level 4

90% of energy is lost as heat

90% of energy is lost as heat

90% of energy is lost as heat

90% of energy is lost as heat

.1% energy

1% energy

10% energy

100% energy

Ecosystem- Two ProcessesSeparate and NOT EQUAL

• Energy Flow

– Energy (as Light) Enters and Exits an Ecosystem (as Heat)

– Everyday, the sun’s energy enters the atmosphere and everyday heat energy exits the atmosphere

– Energy is not recycled.

• Nutrient Cycle– Nutrients (Carbon,

Nitrogen, Phosphorus, etc.) found on Earth are used and reused in ecosystems

– No new nutrients are added to those we have on Earth, and no nutrients exit the Earth

Nutrient Cycles

• Food Webs and Food Chains – Illustrate the– feeding

relationships and

– movement of nutrients and energy through an ecosystem

Plants get their Nutrients from

• CO2 in the air and H2O from the soil

• Trace elements (nutrients), such as nitrogen, phosphorus, potassium, calcium are also found in the soil.

Herbivores get their nutrients from eating plants

Carnivores get their nutrients from eating other animals

Just Kidding!!! There are NO Killer Rabbits!

All Animals and Plants eventually Die and are

Decomposed

• Nutrients in the organism are returned to the soil,

Or the Ocean

Or the Atmosphere

Nutrients are then Reused

• And Reused…• And Reused… • And Reused… • And Reused…• And Reused…• And Reused…• And Reused…• And Reused…• And Reused…

Deep in the Ocean

• Another Nutrient Cycle Exists alongside of hydrothermal vents.

• Energy is provided through chemical activity.

• Nutrients cycle within the depths from one organism to another.

Nutrients Cycles

Water Cycle

Phosphorus cycle

Food Chains (nutrients)

• One organism is followed by a second organism in a food chain.

Food Web (nutrients)

• (All of the) Complex feeding relationships in an ecosystem.