The Material Plane
The Material Plane is the primary plane of existence in the campaign. This is the most stable plane, and the one in which most of the story events happen. There are often many extraplanar entities that visit or live on this plane, as the Material Plane is considered to be one of the safest planes in the multiverse.
Fauna & Flora
The material plane has a much larger variety of flora and fauna than most of the other planes, due to its high levels of Magic Flow rapidly evolving creatures to new and unique forms. While some planes are able to match this variety, most tend to stay stagnant in new diversity much longer than the material plane does. On top of this, many gods choose the material plane as their "testing ground" for new species of creatures, which helps lead to the diversity.
Like flora and fauna, the multitude of planets that exist on the material plane host incomprehensible variety when compared to many other planes. Magic frequently seeps into various natural resources, changing them for better or for worse into drastically different resources than they were before.