Would periodic fires from lightning strikes encourage growth of a prairie or a forest?

Question

Thanks for any help.

And why would it encourage the one it does.

Answer 1

Yes. Periodic fires allow dead grass and other dead plant material to decompose much faster than if there was no fire. This way nutrients are returned to the soil much faster and hence more plant life is able to grow.

Answer 2

In forests, some trees have seeds that can only germinate after they have been partially burnt, (here in Australia, anyway), this is an advantage due to the lack of competition after a fire has come through and cleared the undergrowth. Unfortunately, they are used to only occasional fires, with the increase in artificially lit fires (arson, deforestation) the younger trees are destroyed before they can produce seeds.
Similarly, prairie fires return carbon to the soil more efficiently than natural decomposition, grasses with deep roots will have less fire damage and will re-shoot, taking advantage of the free carbon.

Answer 3

Lightening strikes would encourage forest growth. It would clear out all the dead branches and trees and leave room for new growth. A prairie is not that cluttered.