Activities‎ > ‎Investigations‎ > ‎Digital Images‎ > ‎

Investigation: Measuring Old Growth Forest Loss


How much old growth forest did we actually lose in
the past few hundred  years?

How much was lost in your state?

In this investigation, you can use the AnalyzingDigitalImages software to determine the percent loss of old growth forests over time by analyzing the four maps below. 
This investigation is from Chapter 3 of the Global Systems Science book, A New World View,  created by Lawrence Hall of Science, University of California, Berkeley.

What is Old Growth Forest?

Old growth forests (sometimes called "ancient" forests) have not been logged for at least 200 years. 
They contain a variety of different tree species of varying ages, including some very large trees that 
are hundreds, or even thousands of years old.

Image showing the destruction of Old Growth Forests from 1620 to 1990
Remaining Old Growth Forests:
The shaded areas in these illustrations show the remaining old growth forests in
the United States in 1620, 1850, 1926, and 1990.
Each dot represents an area of 25,000 acres of old growth forest.
Data are from Paullin, Charles Oscar, Atlas of the Historical Geography of the United States,
Edited by John K. Wright, Greenwood Press, Westport, Connecticut, 1932, 1975;
Findley, Rowe, and Blair, James Pl, "Will We Save Our Own?" National Geographic, vol. 178, no. 3, Sept 1990, p. 120;
and the Wilderness Society.

What to do...

Download and launch AnalyzingDigitalImages. See "If You Don't Have the Software..." section below for strategies of how to do "Forest Analysis: without the software.

The "Forest Analysis" portion of the AnalyzingDigitalImages program allows you to explore the amount of old growth forest lost across the country according to the maps above. The software allows you to draw a box in any area of a map and simultaneous identical boxes are drawn in the other three maps, with the percentage of old growth shown for each near the bottom of the computer display.


If You Don't Have the Software...

You can still do analysis by superimposing a grid over a printed version of the maps and counting the number of grid squares that have old growth forest in a particular region of interest. Some grid squares will be only partially filled, so you can estimate by counting squares as "full" if they are mostly full (black), "empty" if they are mostly empty, and "1/2 square" if they are close to 1/2 full.

 

Questions

    How much old growth forest was lost in your state?

    How does your state compare with other states in terms of amount of old growth forest lost? How does your state compare with the national average and to other states in terms of amount of old growth forest? Since you are restricted to rectangular boxes which can't match most state boundaries, your measurements are approximations.

    Which state lost the least old growth forest?

    How much old growth forest was lost in your region, in a particular size box around your city or town?

    Compare the loss of old growth forest in a particular size box around your city or town with that of identically sized boxes around cities or towns where you have friends, relatives, or a city/town that interests you.

    Are there any areas that had an increase in old growth forest during a particular time? If so, how could this happen?

    What additional questions come to your mind that you cannot answer with the data given? Write these along with your summary statement.


Back to Digital Image Investigations