The basic tendencies of an oak tree are genetically determined and they are generally the same from tree to tree (trunks grow directly away from the center of the earth, and branches and leaves grow towards the light). However, each tree takes on a different shape based on environmental factors.
In the image below, note the odd and seemingly irrational shape of the tree crowns.
The logic only becomes clear when you see the same five trees shown in their actual environmental context. Each tree within the cluster is growing in such a way as to gain the most exposure to light, considering the constraints imposed upon it by the neighboring trees.
A clear example shown below demonstrates the principle in its purest form. The oak tree on the left has grown in a wide open field, with generous access to light all around. It shows the characteristic broad crown, where leaves and branches expand outward towards the readily available light. The oak tree on the right has grown within a forest, with other trees all around it. Its leaves and branches have been forced upwards towards the light, and the lower level branches do not exist, because they would have little access to light within the forest.
In the image below, note the odd and seemingly irrational shape of the tree crowns.
A clear example shown below demonstrates the principle in its purest form. The oak tree on the left has grown in a wide open field, with generous access to light all around. It shows the characteristic broad crown, where leaves and branches expand outward towards the readily available light. The oak tree on the right has grown within a forest, with other trees all around it. Its leaves and branches have been forced upwards towards the light, and the lower level branches do not exist, because they would have little access to light within the forest.
