FUNDAMENTALS OF ECOLOGY

“Ecosystem Dynamics”

What does the term dynamics mean to you?

Dynamics means change

Ecosystems need two major factors to function as a working system.

Matter (stuff) atoms, molecules, materials

Energy, the ability to change “stuff”

EXPLAIN ENERGY TRANSFER

With your table partner, explain how energy moves through the system pictured.

QUESTIONS: 1) Where does the energy for an ecosystem originate (start?) 2) From where does the small fish obtain the energy it needs? 3) Does one small fish fulfill the energy needs of the larger fish? 4) Do you think that all of the energy in one step makes it to the next level as it is consumed? If not, where might it go?

There are two important laws in science that govern energy movement in an ecosystem. They are the first and second law of thermodynamics.

First Law: Energy can not be created or destroyed only transferred from system to system.

Second Law: At every energy transfer some energy is transferred from the system as heat energy.

So if energy can’t be created or destroyed from where does it come?

Energy transfers:

Heat Loss:

IDENTIFY THE NAMES AND ENERGY LEVELS…

ACTIVITY

Each energy level in our ecosystem has a name:Producers=Plants/Algae=AutotrophsProducers get their name because they are the first step in an ecosystem, they “produce” food. They transfer sunlight energy into usable food energy. While they don’t make the energy they do transfer it from sunlight to food.

Consumers=organisms that cannot make their own food must eat other organisms. They are known as consumers, sometimes they are called heterotrophs. They feed either directly or indirectly on producers for their energy needs. Do you know some common consumers?

Consumers can be divided up into several subcategories including: Herbivores,, carnivores, omnivores, detrivores, and decomposers. Can you define and give examples of each of these consumers, discuss your ideas with your table partner.

Can you define the following and provide an example of each type of consumer?

Herbivores: Carnivore: Omnivores: Detritivores: Decomposers:

Herbivores:

Carnivores:

Omnivores:

Scavengers:

Detritivores:

Decomposers:

Consumer trophic level classifications:

Depending on what the organism does for energy it may be referred to as a primary consumer, secondary consumer or tertiary consumer. Primary consumers are almost always herbivore, while secondary and tertiary consumers are usually omnivores or carnivores. Look carefully at the following picture, can you identify all the levels of consumers?

The total number and types of organisms (biotic factors) in a given environment interacting together are known as the ___________.

Community

Here is an example of an aquatic community.

TROPHIC LEVELS

Tropic levels are the levels of nourishment (energy levels) in a food chain.

____________________ is a trophic level.

____________________ is a trophic level. Etc…

producer

carnivore

Living organisms that transfer energy and recycle nutrients through an ecosystem make up what is known as the community in an ecosystem.

Energy flow through the community can be represented in

several ways: FOOD CHAINS, FOOD WEBS, and

ENERGY PYRAMIDS-(Oh my!)

Food Chains: demonstrate an energy flow or pathway through the ecosystem.

Can you and your table partner make a food chain with 4 energy transfers that could be

found in Northbrook?

Food webs: demonstrate the feeding relationships and biodiversity of the ecosystem. The food web uses arrows to demonstrate the flow of energy through the web. Note the increased complexity in the web vs. the food chain.

Aquatic Food Web

Notice the many different arrows going from the frog. A food web shows what the frog will eat AND what eats the frog.

Energy pyramids: demonstrates the energy/biomass (amount of living

matter) availabile at each trophic level in an ecosystem.

Energy/Biomass pyramid: What do you observe?

                                                           

What happens to the shape of the chart as we get higher? What happens to the number of

organisms? Why?

What biotic and abiotic factors do you think might limit the biomass at each trophic level in an ecosystem?

More energy pyramids (note what happens to the number/mass of organisms at each level as the energy is passed through an ecosystem, where does it go?)

                                                                                                              

               

Why do you think the number of steps in a food chain or levels in a food pyramid is usually limited to only 4 or 5 steps? (hint: What do you know about energy?)

The survival activity/ Or Relay

What did the packaging peanuts represent?What did the passing of the peanuts represent?What does each student represent?What does dropping the peanuts on the ground represent?

It is important to remember that energy flows in only one direction

and does not cycle through the ecosystem.

However, nutrients and organic compounds do cycle through the ecosystem and are used

by living organisms over and over again. What are some cycles that exist on earth in order to circulate nutrients throughout out

ecosystem?

THE CYCLES

Cycles Cycle defined: A

series of regularly reoccurring events that usually ends up back at the original starting point.

As producers, consumers and decomposers grow and die, they are using life’s essential chemicals or nutrients, taking these nutrients from and returning them to their reservoirs in the earth’s air, soil, and waters over and over again.

Some common cycles include the following: The Water Cycle. (Much more on this one later.)

The carbon cycle

The Nitrogen Cycle

The Phosphate Cycle

It is important to remember that matter cycles through an ecosystem, the world has been using the same molecules over and over again. The water that was in a dinosaur some 500 million years ago may be in us right now.

It is also important to remember that while matter continually cycles through and ecosystem, energy does not. It must constantly be supplied to make the system run.

Answer the questions in the cycles in Nature activity in your packet.

ADAPTATIONS TO AN ECOSYSTEM

Adaptation defined: A characteristic or feature of an

organism that allows it to survive or improves the likelihood it will survive and reproduce in its environment .

Adaptation is caused by change. Because living organisms are in the

process of both acting upon their surroundings and being acted upon, all plants and animals and the places where they live are in the process of becoming something else in order to survive as a species.

Adaptation In the overall story of life, some

plants and animals end up with new and successful ways of meeting their needs by solving the problems brought about by the changes that occur in their environment.

2 Types of adaptations: Structural: how the organism is put

together (physical features) Some scientists also break these types of adaptations down to include chemical adaptations.

Behavioral: how the organism acts. Using response cards, decide whether the

following are structural “S” or behavioral “B” adaptations

Geese flying south for the winter

The feather

Building a nest

Hollow bones

Hunting food

Feeding young

Webbed feet

Specialized Beaks

Camouflage

Flushing when startled

Adaptation Activity: the creature

Conclusion Consider the themes within the ecology unit

that we have covered. They have included: abiotic and biotic factors, biodiversity, community, environment, energy, cycles, and change/adaptation. These themes along with the common characteristics of life and the definition of science will be covered on our unit one exam.

The End (actually we are just getting started. )