This summer\'s U.S. drought could damage trees as well as agricultural crops, and some could die or be affected for years to come, researchers say. Although trees have deeper moisture-reaching roots than agricultural crops, it doesn\'t make them immune to prolonged drought, Purdue University urban forestry specialist Lindsey Purcell said. \"Drought can have a major impact on tree health and survival by effectively slowing and reducing growth,\" he said in a Purdue release Thursday. \"If drought is severe enough or lasts for a prolonged period of time -- such as what we\'re experiencing now -- it also can cause death to all or portions of a tree.\" A more common effect of drought is to reduce a tree\'s ability to withstand insects and diseases, he said. A water-deprived tree will see a significantly lowering of its energy reserves needed to produce chemicals that ward off pathogens, he said.