Pruning Type Affects Decay And Structure Of Crapemyrtle

Abstract

Lagerstroemia ´ 'Natchez' trees were topped, pollarded, or not pruned for 4 consecutive years. The first time trees were pruned in 1998, pollarding required more time than topping. However, the time required to top trees increased in each subsequent year; pollarding time remained the same for each year. Longitudinal sections through stems showed that barrier zones and decay extended farther behind heading cuts on topped trees 5 years after the initial pruning than with the cuts on pollarded trees. Trees in the topping treatment formed a visible, dark-colored barrier zone along the cambium present at the time of wounding, averaging 74 cm (2.5 ft) in length, originating from the heading cuts made through 4- to 5-year-old wood. Barrier zone length on pollarded trees was only 1.8 cm (0.7 in) behind the original heading cuts through 2- to 3-year-old wood. Topping trees resulted in a sixfold increase in the volume of wood contained in dead stubs in the canopy compared to pollarding trees. Topping increased the need for cleaning the canopy of dead branches. A collar formed at the base of sprouts that were less than 0.64 the diameter of the largest sprout 5 years after the original heading cuts on trees in the topped treatment.

Potential hazard characteristics of trees with hollows, cavities and fruiting bodies growing along pedestrian routes

“…Our study brings evidence that trunk hollows statistically do not have an adverse effect on tree vitality. Although previous research showed that improper maintenance, like heavy pruning, may result in exposure to fungal infection and a higher risk of failure in mature trees 36 , 37 , 86 , a cavity/hollow presence should not be perceived as a death sentence for the tree. The final decision on tree removal should be deeply considered and supported using SoT analysis.…”