A forest has fertile soil and light is able to penetrate the canopy resulting in richly diversified understory vegetation and stratification of animals. What type of forest is this?

The correct answer is - temperate deciduous forest.

The temperate deciduous forests are forests that are found in the mid-latitudes. These trees in these forests shed their leafs during the late autumn, and grow them again in the spring. They exist in regions where there's four clearly defined seasons.

The canopies of these forests do not stop all the light, but instead, some of the light riches the surface, while in the colder period the light has no obstacle to reach the surface. The soil is deep and fertile, which is the result of the shedding of leafs in most part, and the vegetation is nicely diversified, where there's numerous plants occupying certain height of the forest. The animals are also relatively abundant, and they are well adapted to both very cold and very warm climates.