Oaks and beech (along with maples) are the major trees in the climatic state of temperate deciduous forests. Large trees are very important to the ecology of the systems that they inhabit. They give three-dimensional structure to the area, providing epiphytic plants as well as many animals a place to live. A single tree can support many herbivores allowing for a greater amount of biomass then is seen in field systems. Their canopies shade the forest floor, setting a selective pressure in light accessibility for any new growth.
Temperate deciduous forests are absent in the southern hemisphere for the most part although they are very common in the Northern hemisphere. The areas in which these forests grow have a warm summer and a winter that is cold enough for the ground to freeze. The loss of leaves is due in part to these winter conditions where the ground water is frozen so the plants are living in a very dry environment. These soils are usually acidic in nature, meaning that nutrient availability is generally low. This makes the land poor for cultivation, however, the under-story is still marked by many herbs and shrubs ranging in height from a few centimeters to several meters tall (Raven, 1999).