What happens to matter in ecosystems

When we speak of matter it literally refers to everything, animals, plants, water, air, rocks, soil, etc. So there are many ways you can describe matter moving through an ecosystem, it depends what matter you are interested in. Here I'll explain a little about organic matter, as in matter that contains carbon, oxygen and hydrogen, and in this case comes from living things.

In an ecosystem there is a hierarchy of feeding among the organisms called trophic levels, basically each level feeds on the one below it and plants form the base because they make there own food using light, water, and Carbon Dioxide.

As seen in the image below each level has a lot of energy and each layer has less than the one before. But in the end that top predator like the eagle, or human, shark, tuna, etc, will usually die without being killed and some animals of each level will also die. This dead matter will build up but luckily there are organisms that eat this, completing the cycle of organic matter.

Organisms that provide this clean up service include fungi, bacteria, insects, worms, all of which are in turn eaten by other trophic levels. The dead organic matter consumed by this clean up crew becomes soil which provides a place for plants to grow. As a result organic matter is always being recycled.

This is summarized below:

You can read more and review with questions and a video here: http://www.ck12.org/book/CK-12-Earth-Science-Concepts-For-Middle-School/section/11.16/

This is a great site to practice material and is free for students.

What happens when you don't get enough of a nutrient?

Millions of sailors in the 15th through 18th centuries died mysteriously. They developed a disease called scurvy. The scurvy, it turns out, was due to the lack of vitamin C in their diets. It wasn't until 1932 that the link between scurvy and vitamin C was made. Without the right nutrients in the right amounts, you can't live. Other animals and plants also need the right nutrients to live.

Living things need nonliving matter as well as energy. What do you think matter is used for? It's used to build bodies. It's also needed to carry out the processes of life. Any nonliving matter that living things need is called a nutrient. Carbon and nitrogen are examples of nutrients. Matter is recycled in ecosystems. In the figure below, you can see how (Figure below).

Decomposers release nutrients when they break down dead organisms.
The nutrients are taken up by plants through their roots.
The nutrients pass to primary consumers when they eat the plants.
The nutrients pass to higher level consumers when they eat lower level consumers.
When living things die, the cycle repeats.

This diagram shows two cycles. One is the cycle of energy, the other is the cycle of matter. Compare the two cycles. Do you see how the Sun keeps adding energy? That’s because energy is lost at each step of the cycle. Matter doesn’t have to be added. Can you explain why?

Summary

Nutrients are crucial to the growth of organisms.
Decomposers break down dead organisms into nutrients and gases so that they can be used by other organisms.
Nutrients can enter or exit an ecosystem at any point and can cycle around the planet.

Review

How does the flow of matter differ from the flow of energy through an ecosystem?
How do nutrients move through an ecosystem?
What would happen to life on Earth if there were no decomposers? Why?

Use the resource below to answer the questions that follow.