Girdling, also called ring-barking, is the complete removal of the bark (consisting of cork cambium or "phellogen", phloem, cambium and sometimes going into the xylem) from around the entire circumference of either a branch or trunk of a woody plant. Girdling results in the death of the area above the girdle over time. A branch completely girdled will fail and when the main trunk of a tree is girdled, the entire tree will die, if it cannot regrow from above to bridge the wound. Human practices of girdling include forestry, horticulture, and vandalism. Foresters use the practice of girdling to thin forests. Animals such as rodents will girdle trees by feeding on outer bark, often during winter under snow. Girdling can also be caused by herbivorous mammals feeding on plant bark and by birds and insects, both of which can effectively girdle a tree by boring rows of adjacent holes. Orchardists use girdling as a cultural technique to yield larger fruit or to set fruit. In viniculture (grape cultivation) the technique is also called cincturing. Forestry and horticulture Like all vascular plants, trees use two vascular tissues for transportation of water and nutrients: the xylem (also known as the wood) and the phloem (the innermost layer of the bark). Girdling results in the removal of the phloem, and death occurs from the inability of the leaves to transport sugars (primarily sucrose) to the roots. In this process, the xylem is left untouched, and the tree can usually still temporarily transport water 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 ATP and transport nutrients upwards through the xylem. 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 felling 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 unintentionally be girdled as they grow, due to friction