Do slacklines damage trees? - What to look out for

Spring has finally arrived and the beautiful weather is attracting Leipzigers to parks and green spaces. Slacklines, hammocks and the like are everywhere. But do they really harm the trees? BUND Leipzig says yes: Yes - if it is not done properly.

"Unfortunately, we see that hammocks and slacklines are often stretched on much too young trees without any trunk protection. This can cause serious damage, especially during the growing season," says Elke Thiess from the Nature and Species Conservation Working Group. "The heat stress and drought of recent years have already damaged our park trees. They should not be exposed to additional stress.

The "weak point" of the trees is the bark and the cambium underneath. This fine and delicate layer of cells is responsible for the thickness of the tree. The bark protects this layer from environmental influences. Depending on the species, the bark varies in thickness and is therefore more or less vulnerable.

When attaching slacklining, tightrope walking, hammocks and the like, it is essential to observe the following rules:

• When slacklining, forces of 500-800kg can act on the tree trunk. For this reason, you should only attach yourself to trees that an adult can just about grasp. This corresponds to a trunk circumference of around 120 cm.
• Use no more than one sling per tree to avoid multiplying the forces acting on the tree.
• The sling should be at least 5 cm wide. Never use ropes!
• Use a separate anchoring sling without knots, closed with a snap hook. Do not tighten the sling.
• Use a bark protector between the trunk and the sling, e.g. carpet remnants, a doormat or similar, also available as tree-friend, tree-protector or webbing slings. The wider the support, the better for the tree.
• Optimally, 4-5 wooden slats or logs of at least 15mm diameter should be placed lengthwise between the sling and the bark protector. This distributes the pressure well and relieves the tree's supply lines.