Forestry, Wildlife & Fisheries News
|
Hardwoods React To Dry SummerBy Bonnie Coblentz MISSISSIPPI STATE -- If the start of fall were determined by hardwoods, fall came a couple months early across much of Mississippi this year. Hardwoods began showing fall yellows, oranges and browns and dropping leaves by early September this summer, about six weeks ahead of schedule. Stephen Dicke, forestry specialist with Mississippi State University's Extension Service, said these trees weren't necessarily dying from the drought. "Don't plan the funeral for your hardwoods yet. Trees that loose leaves early are likely to live through this drought and put out new leaves in the spring," Dicke said. "Trees shed leaves to help them conserve water. Hardwoods in the midst of a severe drought are expected to do this." While it's a bit late to help them this year, water trees during a severe drought to prevent them from being stressed to the point where they have to shed leaves to survive. Dicke said some oak trees may not have survived a second summer in a row of drought. He said red oaks such as the live oak, cherrybark oak and water or pin oak are especially susceptible to drought damage. "Most trees with shriveled, dead leaves hanging on the branches have more serious damage. This indicates there are dead twigs and branches, not just dead leaves," Dicke said. "These trees may not recover from the drought." If most trees in an area have dead, hanging leaves, consider a salvage sale to remove these. Extension agents or forestry professionals can help landowners with this decision. Oaks are not the only trees in trouble from drought. "Several tree species can be killed by drought, especially understory trees that typically live in moist conditions. Dogwoods, beeches and magnolias all fit in this category. They do not like to be without water," Dicke said. Magnolias and dogwoods with dry shriveled leaves are probably in drought trouble, but beeches can be deceiving. The beech leaves typically dry and shrivel in the fall, but stay on the trees through the winter. Landowners with beech trees won't know until spring whether their trees survived the drought this year. Oak trees that survived the drought by dropping leaves are still not out of the woods yet. Stressed trees are much more susceptible to insect and disease problems, and red oaks can get oak decline, a fast- acting, killer disease. "Several areas in Mississippi already are starting to experience outbreaks of oak decline," Dicke said. "Long-term drought stress and oak decline go hand-in-hand, but not since the drought of 1978 to 1980 has our oak population been so susceptible to this disease." Oak decline begins by killing the branches in the top and center of the tree, leaving the lower branches alive and thinning yellowing leaves that remain. As the disease progresses, bark falls off the trunk and gray or black fungal patches appear. This disease is spread by woodborers, which are long-horned beetles, and root grafts, or places where the tiny roots of different trees make contact and sometimes grow together. "The best way to protect trees is prevention," Dicke said. "Isolate infected trees to prevent the disease spreading to nearby healthy specimens." In landscapes, infected trees are often harvested and a trench dug around the tree to sever all infected roots. In timber stands, infected trees are cut down and the stumps treated to kill the roots quickly. Keep trees healthy and monitor them for any signs of illness or decline. Call in a forestry professional at the first sign of trouble. Released:
Oct. 2, 2000 |
|
|
