There are many different subtypes of forest within each of these categories. Which kind of forest can grow depends on local soils, temperatures and rainfall. For example, in southern Europe, long hot summers encourage the growth of a special kind of vegetation called the Mediterranean scrublands. Although they rarely grow thickly enough to be called a true forest, the trees in the Mediterranean scrub lands include small oaks and pines.

     Overgrazing by sheep and goats has changed much of the once-forested areas of the Mediterranean into scrubland called "maquis". Mediterranean scrublands are rich in wildflowers and birds, especially insect-eating birds which are abundant in summer.