SimuLab 17: Gathering Statistics in Blaze

You need the Blaze program to complete this SimuLab. You can download it to your computer or use it online in a Java applet.

Download Blaze:

Mac OS 7.x
Windows 95/98/NT/2000

What if no one is around to fight the fire after the forest is grown? (You may own so many forest plots in different locations that you cannot fly the helicopter over each one in person!) When there is no active fire fighting, we call the resulting forest unmanaged .

Q7.6: What is your best strategy for maximizing the number of trees that survive fire in an unmanaged forest?

Investigate this question by using the Gather Statistics command under the Mode menu. Now there will no longer be a water supply or helicopter to deliver the water. The forest just burns from the left without hindrance except for the barriers provided by empty spaces between trees. The number of spaces depends on the setting of the probability p that determines the density of trees in the forest.

Try various probability settings. You can use the Continuous button to set up a number of automatic runs at a given probability. The results are summarized for you in the Table window under the Windows menu. The table automatically records data from every run made in Gather Statistics mode. You can take averages of any set of runs, as well as delete runs from the table. You can also print the table using the Print Table command menu, or export the table into a commercial spreadsheet using Export Table. Both of these commands are under the File menu.

Q7.7: Which value of the probability p gives you the greatest number of surviving trees, on the average, in an unmanaged forest?

One column in the table records whether or not the fire burns all the way from one side of the forest to the other side. A graph of these cases is titled Fraction Burned Across in the Windows menu.

Q7.8: Is there any relation between the probability that gives you the most surviving trees and the lowest probability at which the fire burns across the forest most of the time?

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