Energy in Ecosystems- WHO EATS WHOM

ENERGY IN ECOSYSTEMS- WHO EATS WHOM

What I will learn

You will learn about where energy comes from in an ecosystem and how it moves through the system by one organism consuming another

Why it is important to understand

It is important to understand that we are interconnected with our environment, that organisms exist in food webs, and depend on one another

How will I know I understand it:

1. you will be able to define producer, consumer and decomposer

2. You will be able to explain how energy moves through an ecosystem from organism to organism.

3. You will be able to explain how matter is recycled in an ecosystem but energy is not

Explore this Phenomenon
When Yellowstone National Park was created there was no protection for wolves or other predators. Ranchers were concerned that the wolves were killing livestock and so the government created predator control programs in the early 1900s. Wolves were hunted and killed.

1. What questions do you have about how the disappearance of wolves affected
the ecosystem?

2. What do you predict happened when the wolves were removed?

3. What evidence would you collect to verify your prediction?

Energy Flow
What is the source of energy for almost all ecosystems?

THE SUN!!!!

What is an ecosystem?

Ecosystem- a system that includes all living organisms (biotic factors) in an area as well as its physical environment (abiotic factors) functioning together in a certain area. 

The sun supports most of Earth's ecosystems. Plants convert light energy from the sun to the chemical energy
found in food. The energy stored by producers is passed to consumers, scavengers, and decomposers as each organism obtains food.

PRODUCER-organisms capable of creating simple carbohydrates such as glucose, from gaseous carbon dioxide.  They make their own food!!  Sometime they are called AUTOTROPHS- which means "self-feeding".    

What do you think these are most often?     

A PLANT!!

CONSUMER- Organisms that need to feed on other organisms to obtain their energy are known as consumers, sometimes called heterotrophs. They don't make their own food! 

SCAVENGER-A scavenger is an organism that consumes mostly decaying plants or animals, such as meat or rotting plant matter.

DECOMPOSERS:

Food Chain
The set of organisms that pass energy from one organism to the next is described as a food chain in the next figure. It is a simplified version of how energy and matter move in an ecosystem. The arrows show the direction the energy and matter move.

Food Web

A food web recognizes that most organisms eat many different things. Food webs are food chains that interconnect with each other. All organisms depend on two global food webs. The aquatic food web is based on phytoplankton as the producer and the land food web is based on plants that grow on dry land. How are these two webs interconnected? Birds or bears that live on land may eat fish, which connects the two food webs. Humans are an important part of both of these food webs; we are at the top of a food web since nothing eats humans as a regular source. That means that humans are the top predators.

This image shows a food web of the Arctic Ocean. Which organisms would be affected if you took out the arctic cod? How would those organisms be affected?

Matter Cycles and Energy Flows
Matter cycles, this means that it is used over and over again. In the carbon cycle, matter, in the form of carbon, is recycled again and again. Carbon can move from the atmosphere into both living and nonliving things, such as rocks and oceans, and then back into the atmosphere. The big idea is that matter is reused; matter cycles through ecosystems.

Energy does not cycle! 

It is converted from one form to another but it is not recycled. The energy that comes from the sun does NOT return to the sun; it is not recycled.
Instead energy flows which is to say that it moves from one form to another. In the carbon cycle energy flows from the sun through plants, as chemical energy, through animals, and eventually into the atmosphere in the form of heat.

Disrupting the Cycle and Flow
Actions have consequences; causes have effects. John Muir said, "When we try to pick anything out by itself, we find it hitched to everything else in the universe."

Nothing in nature exists in isolation! Changes to an ecosystem affect the stability of cycling matter and the flow of energy
among living and nonliving parts of that ecosystem. Consider a forest that has been clear cut which means that all of the big trees were removed. The cycling of carbon through that forest ecosystem would be significantly impacted; it would influence both the ecosystem’s living and nonliving components. The living things that relied on the trees for food would be denied their carbon and energy source and the carbon in the atmosphere would increase as a result of decreased photosynthesis. 

Putting It Together

1. Explain how your understanding has changed about the flow of energy and the
cycling of matter in an ecosystem.

2. Think of another phenomenon that applies the concept of the flow of energy in
ecosystems.

3. Explain what happened with wolves in Yellowstone based on what you have
learned in this section.