Why Trees Change in Autumn

by Ivy Long

For a long time scientist have tried to under stand why changes happen to trees in the autumn. Weather is one of the things that effects the color of the leaf. warm, summer days, and cool, crisp but not freezing nights seem to bring the most spectacular color displays. During these day sugar is produce in the leaf but the cool nights closing the veins prevent the sugar from moving out. Which makes the leaf have tints of reds, purples, and crimson. Trees also have a protection to not freeze during winter and autumn. This is done by the tree producing a heavy wax everywhere. This is how the tree changes in autumn.

http://www.na.fs.fed.us/fhp/pubs/leaves/leaves.shtm