Bark stripping by cattle in silvopastoral systems

Abstract

Silvopastoral systems, consisting of the combined management of pastures, woody perennials and animals, are increasingly adopted throughout the world, especially in the tropics. However, reports of problems to the trees caused by the animals grazing these areas are also increasing. Damages inflicted by cattle to adult trees may include branch breakage, trunk breakage, leaves browsing and bark stripping. Bark stripping may cause severe damage to the trees: it can decrease the value of the timber, and the injuries may lead to diseases or even death of the tree. Bark stripping is caused by multiple factors. It can be related to (i) dietary deficiency (food quantity or quality; fiber, protein, energy, mineral deficiencies); (ii) social learning—from dam or herdmates; (iii) learning and post-ingestive feedback; (iv) stress and boredom, although the presence of trees gives cattle the opportunity to broaden the repertoire of natural behaviors; (v) pharmaceutical compounds used to control/treat diseases. In this article we review reports of bark stripping caused by livestock, specially cattle and sheep, characterizing the conditions for the occurrence of damage. We suggest planning and management strategies that could decrease the risk of bark stripping to trees in silvopastoral systems.