They're not. Koalas do not live in the deciduous forest. They live in eucalyptus bushland, which is evergreen. Eucalyptus trees, on which koalas feed, do not lose their leaves.
The taiga, or boreal forest, is given to high seasonality with a long season during which temperatures are below the freezing point of water. As such, trees must be conifers, with very limited leaves (needles) adapted to the cold, or be deciduous trees that are well adapted to the stress involved in losing its leaves every year. For instance, I live in the central region of Alaska. We have deciduous trees and conifers. The farther north you go though, the fewer deciduous trees there are.
Both oak and pine trees can live in a deciduous forest. All oak trees are considered a deciduous plant. Pine trees are conifers and mostly not deciduous however there are a few genera that are (Larix, Pseudolarix, Glyptostrobus, Metasequoia and Taxodium). (http://en.wikipedia.org/wiki/Conifer)
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Deciduous trees, such as Oak, Beech and Hickory.
Deciduous forests support a wide variety of plant and animal species. The exact number of species can vary, but it can be in the range of thousands. Species include various trees, mammals, birds, insects, and more that have adapted to this type of forest environment.
Deciduous generally refers to a forest in a region that has four distinct seasons and not to deserts. There are, however, come deciduous trees that live in deserts.,
They have learned to live in deciduous forest and more temperate areas than ever before.
They live in it until they are adapted.
Deciduous trees lose their leaves in the autumn. Mostly these are broadleaf trees, but some conifers are also deciduous. In New Zealand, there are only a couple of species that mostly lose their leaves in the winter. The generalization that broadleaf trees lose their leaves in the winter is a northern hemisphere misbelief.
A honey locust is a deciduous tree, meaning it sheds its leaves annually in the fall. It is not a coniferous tree, which are typically evergreen and bear cones.
Deciduous trees are trees that lose their leaves at the end of the growing season. This process is known as leaf abscission. Examples of deciduous trees include maple, oak, and birch.