Deciduous forests are made of trees that lose their leaves seasonally and are leafless for part of each year. The tropical deciduous forest is green during the rainy season and bare during the annual drought. The temperate deciduous forest is green during the wet, warm summers and leafless during the cold winters with the leaves turning yellow and red before falling. Temperate deciduous forests once covered large portions of Europe, eastern United States, Japan, and eastern China. Species diversity is highest in Asia and lowest in Europe. In the United States deciduous forest, 67 species of trees exist.