This may seem contradictory, but it only means that extreme soil conditions, either too wet or too dry for forests, are satisfactory for savannas.

这看起来很矛盾，但这就意味着对于森林来说，过湿或过干的极端土壤条件才适合热带草原。

youdao

Most come from the treetops in wet tropical forests in Central and South America.

VOA: special.2010.04.06

With more than 20 feet of rain a year, these forests are as wet - and correspondingly lush - as a tropical rainforest.

BBC: Hiking through a microcosm of Earth