Flood

Although some tree species are tolerant of periodic or even prolonged flooding, most tree species are severely stressed by flood events. Roots require oxygen for cellular respiration, which is the process of metabolizing sugars to produce energy. The energy produced from respiration is used by trees to power a wide variety of physiological processes necessary to stay alive. During floods, tree roots become starved of oxygen, and therefore cannot undergo cellular respiration. If flooding is prolonged, the entire root system can be severely damaged, eventually leading to decline or death of the tree. Flood tolerant species have evolved mechanisms to transport oxygen from the crown of the tree into the roots, while flood intolerant species lack this oxygen transport mechanism. Flooding while trees are dormant is usually less damaging that flooding that occurs during the growing season. Flood damage symptoms may take years to develop and are difficult to diagnose because they resemble many other root disorders and diseases. Be aware that prolonged soil saturation can have the same effect as floods.