English to French Other Environment & Ecology

Hello,

I am translating an article for mongabay.org where the term lowland forest comes up.
Here is the paragraph:

"Most of the forest area that was converted consisted of disturbed natural lowland forest. There's a simple explanation for this trend: with its valuable timber extracted, lowland forest offers low commercial returns for developers. But converting it to an oil palm plantation is a highly profitable proposition. Lowland areas tend to be targeted because they are more suited to cultivation and generally have better access than upland areas."

from this article http://news.mongabay.com/2013/1112-palm-oil-data.html

I would have written "forêts situées en plaines" but I'm not sure.
Any ideas?
Thank you and have a good day!