Urban trees also at risk in drought

WEST LAFAYETTE, Ind., July 19 (UPI) -- 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.