Dead and decaying wood is an important part of the ecosystem of any woodland. As we cut and coppice in Pondhead, there is a temptation to tidy up deadwood but, unless it presents a safety hazard or is causing an obstruction, the rule is to leave it where found. Woodland management should never be confused with landscape gardening. We’re trying to improve woodland biodiversity (the variety of plant and animal life in a particular habitat), not become the next incarnation of Capability Brown! The pursuit of tidiness when managing a woodland is usually the opposite of conservation.
Species which depend on deadwood as a habitat or food source for all or part of their life cycle include lichens, fungi, mosses and a vast array of different kinds of invertebrates, hole-nesting birds and bats. The invertebrates that assist the decay process also provide a food source for other wildlife species. Estimates vary, but up to 40% of woodland species depend in one shape or form on the ecosystem that deadwood provides. One third of all woodland birds nest in holes or cavities in standing dead trees, and large, hollowing trees provide ideal roosting sites for species such as the great spotted woodpecker and various owls. At least ten of our fifteen bat species use tree holes for summer and winter roosts.
The following are different types of deadwood typically found in a woodland: –
The decay process provides a steady, slow-release source of nitrogen to other plants and is also thought to play a significant role in carbon storage. Fallen logs can also increase soil stability within a woodland, so leave them where you find them unless they create a hazard. If deadwood has to be moved then it should be moved as short a distance as possible, keeping it in contact with the ground. The creation of log piles (nature piles) from surplus/unusable timber is good practice and, ideally, these should be located in shady or damp areas wherever possible. These piles of logs provide vital shelter for a great variety of woodland creatures from newts and toads, to woodlice and millipedes. While standing and fallen deadwood are both important, standing deadwood has a greater habitat value for more species. For this reason, standing dead trees are not usually felled unless they present a health and safety hazard. The inhabitants of dead standing trees will often be different to those in fallen deadwood and this may again be different to those in log piles. As great a variety as possible of rotting wood micro habitats is beneficial to any woodland. It is rare for deadwood to represent a threat of disease.
Large woody debris also plays a vital role in creating diverse ecological niches within forest streams and rivers. It can provide shelter for fish and create suitable areas for spawning. The development of deadwood ‘debris dams’ also slows the flow of a stream which helps to reduce soil erosion from its banks. For these reasons, it is not good practice to clear debris dams that have been created naturally.
Decaying wood is an essential part of a healthy woodland. In fact, it is under-represented in most UK woodlands.