Embedded Wire in Tree Roots: Implications for Tree Growth and Root Function

Abstract

Experiments with two-year-old seedlings of Fraxinus pennsylvanica and Celtis occidenlalis and two yearold whips of Populus angulata x plantierensis were designed to study the effect of root girdling by wire. Overall growth, foliar nutrient content, xylem anatomy, root carbohydrate content, xylem water potential, and rate of transpiration were studied six months after girdling. Neither greenhouse grown seedlings nor field grown whips subjected to root girdling by wire grew less than those without girdling wire. Full girdling significantly reduced foliage dry weight in Fraxinus and the rate of transpiration in Fraxinus and Celtis. A gradient of water potential was observed in the xylem across the wire girdle in seedlings of these two species. The amount of carbohydrate present in root tissue and its distribution in relation to the wire was slightly influenced by girdling in all three species.