In this exercise, you will explore net primary productivity across the globe and study patterns of deforestation in different regions of the world.

Net Primary Productivity

Section 1

Go to https://earthobservatory.nasa.gov/global-maps/MOD17A2_M_PSN (Links to an external site.)

1. What do negative net primary productivity values mean?

Use the arrows that accompany the map to play the animation.

2. The northern part of South America has high positive net primary productivity year-round. Why?

3. In the United States, the net primary productivity is lower in the Southwest than in the Northeast year-round. Why?

Go to NOAA’s Earth System Research Laboratory at https://www.esrl.noaa.gov/gmd/ccgg/trends/ (Links to an external site.) to see Trends in Atmospheric Carbon Dioxide.

4. How do monthly mean CO2 concentrations change over the course of one year at Mauna Loa Observatory in Hawai’i? Explain this pattern.

Changes in Global Forest Cover

Section 2

Go to http://http://earthenginepartners.appspot.com (Links to an external site.) to see the Global Forest Change map.

5. How are trees defined there?

6. What is meant by “Forest Cover Loss”? By “Forest Cover Gain”?

Click on “Data Products” and choose “Loss/Extent/Gain (Red/Green/Blue)” from its menu.

7. In what ranges of latitudes are most forests found? Why? (Think about the general circulation of air and global precipitation patterns. Refer to Figures 5-24, 5-25, and 6-35).

8. Which areas show the greatest amount of forest loss? What major biomes are located in those areas?

In the “Example Locations” menu, choose “Deforestation in Paraguay” and click on “Zoom to area.” Use the following “Data Products” to answer the questions that follow: “Forest Cover Loss 2000-2016 (Transparent)”; “Forest Cover Gain 2000-2012 (Transparent)”; “2000 Percent Tree Cover (Transparent).”

9. How does forest loss compare with forest gain here?

10. Zoom in three levels and pan around northern Paraguay. Use the graphic scale in the map to visually gain a sense of the size of the forest clearings in northern and western Paraguay. Approximately how large are they? What does the size and shape of the clearings tell you about the type of economic activity practiced here? Hint: Read the description at the bottom right hand column.

In the “Example Locations” menu, choose “Finnish and Russian Forestry” and click on “Zoom to area.” Use the following “Data Products” to answer the questions that follow: “Forest Cover Loss 2000-2016 (Transparent)”; “Forest Cover Gain 2000-2012 (Transparent)”; “2000 Percent Tree Cover (Transparent).”

11. How does forest loss compare with forest gain here in the Finnish and Russian sides?

12. Zoom in five levels and pan around the area. Use the graphic scale in the map to visually gain a sense of the size of the forest clearings in Finland and/or Russia. Approximately how large are they? What does their size, shape and amount of forest loss/gain tell you about the type of economic activity practiced here? How does this compare to the situation in Paraguay? Hint: Read the description at the bottom right hand column.