Name: ___________________________________________________ Period:______________

Traveling Lab-Biogeochemical Cycles

There are a few types of atoms that can be a part of a plant one day, an animal the next day, and then travel downstream as a part of a river’s water the following day. These atoms can be a part of both living things like plants and animals, as well as non-living things like water, air, and even rocks. The same atoms are recycled over and over in different parts of the Earth. This type of cycle of atoms between living and non-living things is known as a biogeochemical cycle.

All of the atoms that are building blocks of living things are a part of biogeochemical cycles. The most common of these are carbon and nitrogen.

Tiny atoms of carbon and nitrogen have no legs to walk, no bicycles, cars, or airplanes. Yet they can travel around the world as a part of biogeochemical cycles.

 

http://www.windows2universe.org/earth/climate/images/carboncycle_sm.jpg

This drawing shows the carbon cycle.

 

 

The Carbon Cycle

Carbon is an element. It is part of oceans, air, rocks, soil and all living things. Carbon doesn’t stay in one place. It is always on the move!

Carbon dioxide is a greenhouse gas and traps heat in the atmosphere. Without it and other greenhouse gases, Earth would be a frozen world. But humans have burned so much fuel that there is about 30% more carbon dioxide in the air today than there was about 150 years ago. The atmosphere has not held this much carbon for at least 420,000 years according to data from ice cores. More greenhouse gases such as carbon dioxide in our atmosphere are causing our planet to become warmer.

Carbon moves through our planet over longer time scales as well. For example, over millions of years weathering of rocks on land can add carbon to surface water which eventually runs off to the ocean. Over long time scales, carbon is removed from seawater when the shells and bones of marine animals and plankton collect on the sea floor. These shells and bones are made of limestone, which contains carbon. When they are deposited on the sea floor, carbon is stored from the rest of the carbon cycle for some amount of time. The amount of limestone deposited in the ocean depends somewhat on the amount of warm, tropical, shallow oceans on the planet because this is where prolific limestone-producing organisms such as corals live.

The Nitrogen Cycle

Nitrogen is an element. It is found in living things like plants and animals. It is also an important part of non-living things like the air above and the dirt below. Atoms of nitrogen don't just stay in one place. They move slowly between living things, dead things, the air, soil and water. These movements are called the nitrogen cycle.

Most of the nitrogen on Earth is in the atmosphere. Approximately 80% of the molecules in Earth's atmosphere are made of two nitrogen atoms bonded together (N2). All plants and animals need nitrogen to make amino acids, proteins and DNA, but the nitrogen in the atmosphere is not in a form that they can use. The molecules of nitrogen in the atmosphere can become “fixed” for living things when they are broken apart during lightning strikes or by certain types of bacteria, or by bacteria associated with bean plants. This process is called nitrogen fixation.

Most plants get the nitrogen they need to grow from the soils or water in which they live. Animals get the nitrogen they need by eating plants or other animals that contain nitrogen. When organisms die, their bodies decompose bringing the nitrogen into soil on land or into ocean water. Bacteria alter the nitrogen into a form that plants are able to use. Other types of bacteria are able to change nitrogen dissolved in waterways into a form that allows it to return to the atmosphere.

Certain actions of humans are causing changes to the nitrogen cycle and the amount of nitrogen that is stored in the land, water, air, and organisms. The use of nitrogen-rich fertilizers can add too much nitrogen in nearby waterways as the fertilizer washes into streams and ponds. The waste associated with livestock farming also adds large amounts of nitrogen into soil and water. The increased nitrate levels cause plants to grow rapidly until they use up the supply and die. The number of plant-eating animals will increase when the plant supply increases and then the animals are left without any food when the plants die.

Text Box: The illustration shows how nitrogen travels through the living and non-living parts of the Earth system.
 

 

http://www.windows2universe.org/earth/climate/images/nitrogencycle_sm.jpg

 

Traveling Nitrogen Passport                             

                                                            

Guess what! In this game you are a nitrogen atom. You are going to travel the nitrogen cycle stopping in many exciting locations - some of which you probably never have been to before.

For each stop along your journey, remember to record where you went and how you got there.

Here's an example of how to fill out each stop along the way:

http://www.windows2universe.org/teacher_resources/images/nitrogen_worksheet1.gif

Directions:

  1. Stamp your start location in the space below.

Start location







Stamp above

  1. Roll the die to find out where to go next. Write How I traveled in the Trip #1 box below (see example at right).
  2. Go to that location in the room and stamp the Trip#1 Where I went box. Then, roll the die to find out where to go next.

 

 

 

Trip #1: How I traveled:

Where I went:








Stamp above

Trip #5: How I traveled:

Where I went:








Stamp above

Trip #2: How I traveled:

Where I went:








Stamp above

Trip #6: How I traveled:

Where I went:








Stamp above

Trip #3: How I traveled:

Where I went:








Stamp above

Trip #7: How I traveled:

Where I went:








Stamp above

Trip #4: How I traveled:

Where I went:








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Trip #8: How I traveled:

Where I went:








Stamp above

  Questions:

1.      What is a biogeochemical cycle?

 

2.      Why do plants and animals need nitrogen?

 

 

3.      What is wrong with the nitrogen in the atmosphere?

 

4.      Name two ways that nitrogen gas is “fixed” into a form of nitrogen that plants can use.

 

 

5.      If you are nitrogen dissolved in groundwater, what are the two places that you can go?

 

6.      What happens to nitrogen in the soil during denitrification?

 

 

7.      How do live animals get the nitrogen that they need?

 

8.      What three places can the nitrogen in animal waste go?

 

 

9.      How is nitrogen stored in dead plants and animals released into the atmosphere?

 

 

10.  What is the problem with using too much nitrogen-rich fertilizer?

 

 

 

Traveling Carbon Passport                           

Start location





Stamp above

 

Trip #1: How I traveled:

Where I went:








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Trip #4: How I traveled:

Where I went:








Stamp above

Trip #2: How I traveled:

Where I went:








Stamp above

Trip #5: How I traveled:

Where I went:








Stamp above

Trip #3: How I traveled:

Where I went:








Stamp above

Trip #6: How I traveled:

Where I went:








Stamp above

Trip #7: How I traveled:

Where I went:








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Trip #8: How I traveled:

Where I went:








Stamp above

Questions:

1.      Name three ways that carbon is returned to the atmosphere.

 

 

 

2.      Why do plants need carbon in the form of CO2?

 

 

 

 

3.      If you are carbon in a live plant, what three places can you go?

 

 

4.      How do live animals get the carbon that they need?

 

 

5.      Where do fossil fuels come from?

 

 

 

6.      If you are carbon stored in a fossil fuel, what two places can you go?

 

 

 

7.      Name three types of organisms that can go through cellular respiration.

 

 

8.      What is a greenhouse gas?