< link rel =" stylesheet " href =" http : / / editor . daum . net / services / blog / css / contents 4 view . css ? ver = 1 . 1 . 95 " type =" text / css "/>< link rel =" stylesheet " href =" http : / / editor . daum . net / services / blog / css / theme 4 view . css ? ver = 1 . 1 . 95 " type =" text / css "/> Study : Fall Colors are Sunscreen for TreesAndrea ThompsonLiveScience Staff WriterLiveScience . com Tue Oct 30 , 10 : 25 AM ETThe fiery red hues that seem to set forest leaves ablaze in autumn are produced in part as a result of the soil that trees grow in and help protect the trees in the winter , a new study finds . The reasons why leaves change from their summer greens to brilliant yellows , oranges and reds has been something of a mystery to scientists because the process required energy , but didn ' t seem to benefit the trees . Orange and yellow pigments , which exist in the leaf all year but only show up once the green chlorophyll leaves the leaf , were better understood than the ruddy pigments on sweetgum and red maple trees . But recent research has shed light on why trees bother producing these pigments , called anthocyanins , which also color raspberries , purple pansies , and red apples . The anthocyanins were known to act as sort of an arboreal sunscreen , protecting leaves from harmful radiation and also keep leaves from freezing . In 2003 , plant physiologist William Hoch of Montana State University found that if anthocyanins were genetically blocked from leaves , they were very vulnerable to sunlight and so sent fewer nutrients to the plant ' s roots for winter storage . The new study , which will be presented Oct . 29 at the Geological Society of America ' s annual meeting , went a step further and showed that producing anthocyanins is beneficial to trees that grow in nitrogen - poor soils because the pigments protect the leaves for longer so they can draw in as many nutrients as possible for storage in roots before winter sets in . " It makes sense that anthocyanin production would have a function , because it requires energy expenditure , " said study leader Emily Habinck , a former University of North Carolina graduate student . So the scarlet hues that take over the leaves in the fall are the sign of a stressed - out tree just trying to survive . " The rainbow of color we see in the fall is not just for our personal human enjoyment , " said soil scientist Martha Eppes , also of UNC . " Rather it is the trees going on about their lives and trying to survive . " Top 10 Poisonous PlantsFall Foliage : Why Leaves Change ColorLife ' s Little Mysteries Original Story : Study : Fall Colors are Sunscreen for Trees