Pollarding

Pollarding is a specific pruning system used to manage tree growth.

This method involves removing the upper branches of a tree. This action encourages the growth of a dense head of foliage and new branches. People use pollarding for many different reasons. It helps maintain trees at a specific height. It also keeps new shoots out of the reach of grazing animals. This practice can help trees live longer. It keeps them in a partially juvenile state. It also reduces the weight and windage of the tree's top section.

The mechanism of pollarding relies on a tree's natural biology. To perform it, a person removes the main apical stems, which are the top-growing parts. This removal releases the growth of many dormant buds located under the bark. These buds are called epicormic growth. These buds then develop into many new shoots. Only certain species can handle this process. Trees without vigorous epicormic growth may die if they lose their leaves and branches. Some smaller species might actually form a coppice stool instead. This happens when cutting the main stem stimulates growth from the base rather than the top.

Different types of pollarding exist based on the desired outcome. One type is used to produce fodder, which is food for livestock. These trees are pruned every two to six years to maximize leafy material. This material is known as pollard hay. Another type is used for wood production. These trees are pruned every eight to fifteen years. This produces upright poles used for fencing or boat construction. Some people harvest supple willow or hazel branches for weaving baskets or fences. In Japan, a specific technique called Daisugi is practiced on Cryptomeria trees.

Pollarding has a very long history. The Roman writer Propertius mentioned it during the 1st century BCE. The practice has been common in Europe since medieval times. In historical England, local people often had the right to pollard trees. This was called the right of estover. It allowed them to collect fuel from common lands or royal forests. In Epping Forest, most trees were pollarded until the late 19th century.

Today, the practice is used in urban forestry worldwide. It helps manage tree size and improves safety in cities. It can even rejuvenate certain species like the Bradford pear.

The practice has significant ecological impacts. When trees are pollarded, the canopy is reduced. This allows more light to reach the forest floor. This increased light can help increase species diversity in the understory.

However, if pollarding stops, the side and top shoots grow into large branches. This can limit the light reaching the ground, as seen in Epping Forest. Pollarding also promotes the formation of tree hollows and rot holes. These cavities are vital for many living things. They provide habitat for thousands of species of insects, such as beetles and hoverflies.

They also support lichens, mosses, and fungi. Birds and bats often use these hollows as nesting or roosting sites.

Many specific tree species are well-suited for pollarding. These are mostly broadleaved trees. Common examples include oaks (Quercus), beeches (Fagus), and maples (Acer). Other suitable trees include hornbeams (Carpinus), planes (Platanus), and willows (Salix). Even a few conifers, like yews (Taxus), can be pollarded. In Africa, the practice is used on moringa trees. This brings nutritious leaves within easy reach for harvesting.

Some pollards are even used as markers. If cut about one metre above the ground, they are called stubs.

The term itself has interesting origins. The word "poll" originally referred to the top of the head. To "poll" meant to crop hair. This idea was extended to the branches of trees and the horns of animals. A "pollard" was originally a term for something that had been polled, like a hornless ox. Over time, the noun became a verb: "pollarding." This practice connects human needs for resources with the complex biological systems of forest management.