The types of beneficial fungi that associate with tree roots can alter the fate of a patch of tropical forest, boosting plant diversity or, conversely, giving one tree species a distinct advantage over many others, finds a study in Ecology Letters which sought to explain a baffling phenomenon in some tropical forests: Small patches of "monodominant forest," where one species makes up more than 60 percent of the trees, form islands of low diversity in the otherwise highly diverse tropical forest growing all around them.
The new study focused on mountain forests in Panama that harbor hundreds of tree species, but which include small patches dominated by the tree species Oreomunnea mexicana.