Why do some forests have undergrowth so thick you can’t get through it, and others are just tree trunk after tree trunk with no undergrowth at all?

Question

Why do some forests have undergrowth so thick you can’t get through it, and others are just tree trunk after tree trunk with no undergrowth at all?

In: Biology

Answer 1

You can divide forest in 3 types

Primary(Old Forest), Secondary(Middle age forest) and Tertiary(Young forest)

Primary= Virgin and old forest with big trees that blocks sunlight and very little undergrowth.

Secondary = Forest that have been intervene by humans or natural disasters such as fires, the sun can reach the ground and there is a good amount of undergrowth.

Tertiary= New forest with a lot of sunlight reaching the ground and lots of undergrowth.

Of course there are exceptions like tropical forest.

Edit: Typos and I add other information