Rainforest Carbon Cycling Model

 

 

Introduction

How does a rainforest contribute to carbon cycling between land and the atmosphere?  Carbon cycles between land (as stored in trees, fossil fuels, and other living and dead organic matter) and the atmosphere (as carbon dioxide gas, CO2).  You have probably heard about "global warming": CO2 gas in the atmosphere is a major contributor to these increasing temperatures because it traps heat, but trees and other plants can pull CO2 out of the atmosphere.

With support from the National Science Foundation, scientists have created a computer model to simulate the effects of rainforest deforestation and agriculture (planting pasture crops) on the amount of CO2 in the atmosphere and on animals living in the rainforest.

Installation of the Rainforest Model

The rainforest model program uses resources provided by ExtendSim, a framework software for running simulation models like this one.  To run the rainforest model:

  1. Download and install the free demo of the simulation software ExtendSim
  2. Download and install the rainforest model.  This is a 40 MB file, so download may take a while. 
    Note that you must install the rainforest model program into the  ExtendSimV7Demo-Player folder so that it can find those resources. Any other location will simply not work. 
  3. To download and print the installation guide, click here.


 

FAQs and Help

1. What is the movie button?
2. What do the numbers below tree mass, organic matter, sloth mass, jaguar mass, pasture mass, cow mass, and people mass represent?
3. In what units are the levels of sunlight, water, and nutrients?

4. How come the amounts of CO2 concentration on the right and the box containing the amounts of CO2 in the atmosphere have different numbers?
5. The simulation is running and I can't change the levels of sunlight, water, and nutrient amounts. Is there something wrong?

6. What is the difference between levels?
7. How come I can't manipulate the sunlight, water, and nutrient amounts in Levels 3 and 4?
8. I clicked on the results button and would like to transfer this information to Microsoft Excel. How do I do this?

1. What is the movie button?

The movie button takes you to the guided tour of the rain forest simulator program. It is highly recommended that your students view this guided tour before starting the simulation.

2. What do the numbers below tree mass, organic matter, sloth mass, jaguar mass, pasture mass, cow mass, and people mass represent?

The numbers below all of the icons represent the amount of total land carbon that each of the factors currently have. As the models run, the numbers change, but if you add up all of the numbers they should add up to the total land carbon amount in the grey box.

3. In what units are the levels of sunlight, water, and nutrients?

Nutrient units are in Mg N/ha (Mega grams of nitrogen per hectare)
Sunlight units are in  J/cm2/day (Joules per centimeter squared per day)
Rainfall units are in mm/mo (millimeters per month)

4. How come the amounts of CO2 concentration on the right and the box containing the amounts of CO2 in the atmosphere have different numbers?

The CO2 concentration on the right is shown as ppm or parts per million (a unit of concentration). This is a different unit than the amount of CO2 in the atmosphere shown in the gray box that lists the CO2 as Mg/ha or Mega grams (1 million grams) per hectare (carbon mass per unit area of land). To convert ppm to Mg/ha, multiply ppm by 15. Conversely, to convert from Mg/ha to ppm, divide Mg/ha by 15.

5. The simulation is running and I can't change the levels of sunlight, water, and nutrient amounts. Is there something wrong?

The model is set so that the only time you can change variables is when the model has finished running. Once the model has finished running, you may change variables and run the model again by pressing the "run model" button.

6. What is the difference between levels?

In level 1, you can experiment with manipulating the sunlight, rain, and nutrient levels by moving the sliders up or down. This will cause a change in tree mass growth, total carbon and atmospheric CO2 levels.
In level 2, you can also manipulate the same variables as in level 1, but land animals have been introduced. This causes a change in the responding variables.
In level 3, there are no variables to manipulate. Instead, you can watch what happens to the levels of land and atmospheric carbon under a different type of land use, pasture, where cows and people are introduced.
In level 4, the only variable you can manipulate is the amount of pasture or forest. Observe how the change in land use affects the carbon stored on land and in the air, as well as the animals.

7. How come I can't manipulate the sunlight, water, and nutrient amounts in Levels 3 and 4?

In levels 3 and 4, the primary concern is to see how the conversion of rainforest to pasture, as well how people and cows, affect the atmospheric CO2 and total land carbon. Because of this, the sunlight, water, and nutrients levels are kept constant.

8. I clicked on the results button and would like to transfer this information to Microsoft Excel. How do I do this?

Right click on the table and click on "Select All" then copy the information. The top row does not transfer. Go to a blank excel worksheet and right click on the cell where you want the information to paste. Select the paste option.