Complex sentence: The spread over a hectare of land was, unlike other trees, created by the tree's outwards growth which, when bent towards the ground (because of their weight), their branches tends to take new roots where they touch the ground.
Split into simpler sentences: The spread over a hectare of land was, unlike other trees, created by the tree's outward growth. When bent towards the ground (because of their weight), the branches tend to take new roots where they touch the ground.