The fractal trees in this poster represent the Ten Sefirot of the kabbalistic Tree of Life. Each tree has three branches that then branch and into three smaller branches - a total of nine, and with the trunk of the tree, ten. Fractals are forms that are self-similar on different scales. How many trees are here? There are eighteen complete trees in the three larger wheels. Eighteen is the gematria (number value) of the Hebrew word for Life Chai חי.
The ancient tree in this picture is at least one thousand years old. Its diameter is almost two meters wide. The insides of olive trees get hollow as they grow older, and their trunks twist in a spiral around their hollow core. I remember taking my wife and kids there when they were younger and all of us could fit inside the hollow core of this beautiful and ancient tree.