HandsOn 27 - Growing a Scattered-Seed Forest

Work in pairs. You need:

First create a random forest on a square grid, with 25 cells in the grid.

Q7.1: Now the model forest is grown. Does it look to you like a real forest? How is it different?

We are now ready to start a fire in our model forest, and see how far it spreads. The fire starts along the left edge of the forest and spreads from one tree to another if they are neighbors (up, down, right, left) on the grid. Here's how it works:

Q7.2: Now you have burned your forest. Did the fire percolate? That is, did it spread all the way from the left edge to at least one tree on the right edge? Or did it stop part way across the grid?

Q7.3: Now you have seen what happens in a model forest where about 50% of the squares are occupied by trees. What would happen if there were more trees? Would the fire be more or less likely to spread all the way across?

Grow a new forest on the same size grid, but this time roll a die for each square, placing a tree if the die comes up 1, 2, 3 or 4 and leaving the square blank if the die shows 5 or 6. Now predict what you expect to happen when you start a fire along the left edge. Will more or fewer fires burn across to the right side of the forest than before? Try it!

Previous: 7.1 - Percolation in Nature

Next: SimuLab 16 - Modeling a Scattered-Seed Forest