57. TREE TRUNK

The redwood is the tallest of trees. The tallest living redwood is said to be 370 feet (113 metres) tall. But what limits the height of a tree? Why can’t a redwood be twice as tall as this, for example?

If we take an imaginary section through the base of the trunk, there will be some limit as to what weight the cells in this section will support. So for a given tree and section, suppose we double the size, scaling the tree by a factor of 2. Then the volume (and so the mass) of the tree will be scaled by a factor of 23 = 8, but the area of the slice will only be scaled by a factor of 22 = 4. Thus we will have doubled the pressure on the cells of the intersection.

We see that the weight the cells of the intersection are able to support limits the size of the tree for each species.


http://en.wikipedia.org/wiki/Tree