There are multiple different forest types on the planet, all of them with their own unique characteristics creating a certain forest ecosystem.
The tropical forests are evergreen, so are the boreal forests, but the temperate forests shade their leaves each autumn and grow them again in the spring. The tropical forests are fully active all year around, the boreal despite being green all the time are not active for big portion of the year, while the temperate forests are active from the end of the winter until mid autumn. The tropical forests create a lot of material for decomposition thus making the top part of the soil very fertile, the boreal forests do not create a lot of material for decomposition but instead very little which makes the soil relatively poor, and the temperate forests create a lot of material for decomposition especially in the autumn when they shed their leaves, thus contributing to very fertile top layer of the soil. The tropical forests have enormous biodiversity, the boreal forests are very monotonous and have very little biodiversity, while the temperate forests are kind of in between with medium level of biodiversity.