Like all vascular plants, trees use two
for transportation of and nutrients: the (also known as the ) and the (the innermost layer of the ). Girdling results in the removal of the, and death occurs from the inability of the to transport (primarily ) to the. In this process, the is left untouched, and the tree can usually still temporarily transport and minerals from the roots to the leaves. Trees normally sprout shoots below the wound; if not, the roots die. Death occurs when the roots can no longer produce and transport nutrients upwards through the. (The formation of new shoots below the wound can be prevented by painting the wound with herbicide.
Ring barking techniques have been developed to disrupt or impede sugar transport in phloem, stimulating early flower production and increasing fruiting, and for controlling plant size, reducing the need for pruning. Girdling is a slow process compared to and is often used only when necessary, such as in the removal of an individual tree from an ecologically protected area without damaging surrounding growth. Accidental girdling is also possible and some activities must be performed with care. Saplings which are tied to a supporting stake may be girdled as they grow, due to friction caused by contact with the tie.
If ropes are tied frequently to a tree (e. g. to tether an animal or moor a boat), the friction of the rope can also lead to the removal of bark. The practice of girdling has been known in Europe for some time. Another example is the girdling of selective trees in some Northern, such as, in order to prevent that fir from massive invasion of the mixed oak woodland. Girdling can be used to create standing dead wood, or. This can provide a valuable habitat for a variety of wildlife, including insects and nesting birds. The tree\’s roots gather water and nutrients from soil.
The water and nutrients are carried up the tree through a series of tiny, tubelike structures called xylem. The xylem transports the water and nutrients to the tree\’s canopy, where they are used by leaves during photosynthesis to manufacture sugars that are food for the tree. The sugars are in the form of sap. The phloem, a layer of cells next to the outer bark, transports the nutrient-rich sap downward to all parts of the tree. The tree uses the sap to grow new limbs, produce flowers and set fruit or seeds. In a pine tree, the sap feeds the tree as it develops pine cones and grows taller and stronger.