Why Do Leaves Change Color?The leaves of most trees are green during the growing seasons of spring and summer. During this season, they change from light to dark green. The green color comes from a substance called chlorophyll. Chlorophyll absorbs light energy for use in photosynthesis, a food-making process that occurs in green plants. 
Brilliant eye-popping colorsThe uniform greens give way to the golds, oranges, reds, purples and bronzes. These pigments are caused by the following substances.yellow color by the pigment xanthophyll orange-red tones by the carotene pigments. red and purple by pigments called anthocyanins The autumn color depends on which of the pigments is most plentiful. As the chlorophyll and other colorful pigments breakdown, all leaves become brownish. Each species of plant has their characteristic fall colors. Red and yellow are the main colors of autumn foliage in the east, and yellow and dark green are the main colors of autumn in the mountains and hills of the West. The dark green colors are from the numerous evergreen (conifer) trees. In the north there are more deciduous trees and therefore more treeswhich change color. In the south are more evergreen species. In the west, on mountains and hillsides, the bright yellow quaking aspens are vivid against a forest of dark green evergreens, such as spruce and fir trees. In the east, the predominant colors are the browns of oaks, golds and yellows of the hickories, sycamores and other species. The reds of red maples and sumacs typify the October displays and draw many foliage watching visitors each year. Here are the foliage colors of the most common tree species are in the list below.Oaks bear oak - yellowish brown black oak - dull brown blackjack oak, pin oak, turkey oak - reddish with orange tinge post oak - brown red oak - dull brown scarlet oak - bright scarlet to deep red Virginia live oak - green this is an evergreen oak) white oak - orange-brown Hickories all hickories have yellow leaves in fall. Maples box-elder - yellow, sometimes reddish red maple - red silver maple - pale yellow striped male - yellow sugar maple - bright orange, turning to yellow Birches birches - all turn shades of yellow Other species American beech - light yellow and turning brownish tan American chestnut - brownish yellow Black tupelo - deep dark red Bigtooth aspen - orange-yellow, turning pale yellow Eastern cottonwood - yellow Eastern sycamore - brown Flowering Dogwood - deep red Pin and wild cherries - reddish, turning yellow Quaking Aspen - yellow varies form pale to deep Sassafras - reddish becoming yellowish Sumacs - orange, turning bright red Sweetgum - orange-red, turing yellow Tamarack (American Larch) - bright yellow needles Tuliptree - bright yellow White ash - maroon, dark reddish green The sequence of colorFall leaf color changes begins at the higher altitudes and progresses to lower altitudes. This is due to the cooler temperatures of higher latitudes and elevations. Trees begin to change along the Canadian border (above this boundary is coniferor evergreen forests) and progresses downward. Leaves change color first in the mountains and move down the mountains into the valleys and coastal areas. The color changes in predictable order. It begins with the red maples and progresses to aspens to sugar maples to oaks. The best fall color conditionsLeaf color varies depending on temperature and and other factors. Lack of enough water from droughts and insect eating can case poor foliage display. Warmer than normal October nights are also bad for fall color display. During the warm nights the trees use the sugar produced in their leaves, so not enough sugar is left for color to develop. Early cool weather brings early fall colors. The best color displays are developed during sunny fall days and cold, frost-free nights. If you would like to know when fall foliage colors are at their peak, most Northern and Mid-Atlantic states have hotlines and tourism websites for information. Fall in PA (Pennsylvania Foliage Watch) Falling LeavesAfter the it dies the tiny pipelines that carried water and food between the leaf and the rest of the tree become plugged. The cells which held the it to the stem dissolve and separate. The dying leaf hangs by a few strands. These strands dry and twist in the wind. When the strands finally break, it falls to the ground. Once on the ground, the it is broken down by tiny organisms in the soil. These tiny organisms (bacteria and fungi), convert the leaf into simple substances used for food. These substances are also absorbed by plant roots and provide food for new growth. The endless circle of life continues . Return from Why do leaves change color? to Nature in Fall
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