Forests are important habitats for birds and, in temperate forests, small mammals which inhabit the dense understorey.

森类来说是重要的栖息地，而且在温带森里，小型的哺乳动居住在稠密的森下层。

Tropical forest is wetter and usually supports only knee-high fires that spread slowly through the understorey.

热带森则较为潮湿，通常只能使及膝高度，并缓慢地在下层植中蔓延。