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

林对鸟类来说是重要栖息地，而且在温带林，哺乳动居住在稠林下层。

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

热带林则较为潮湿，通常只能使火烧到及膝高度，并缓慢地在下层植中蔓延。