From publisher blurb:
The natural world holds its share of wonders, mysteries and terrors. In eldritch forests throughout the known world, bewitching spirits hide from the eyes of Men while milk-pale creatures toil below the surface in a never-ending cycle of life, death and rebirth. In distant lands, a tribe of sentient reptilians hunt and swim the dark lagoons and dense jungles of their island homeland.
Forces of Nature is a supplement containing the new reptilian Salaam stock and two character classes: the Dryad Preserver and the Myconid Envoy. Also included: new creatures (Treants, Myconids, Drael riding beasts), a new skill (Dancer) and more!