Standing dead trees (snags) and fallen debris provide a fantastic array of ‘microhabitats’. There is a breathtaking range of saproxylic (deadwood-dependent) organisms including fungi, lichens, invertebrates, mosses and birds, many of them having very specific requirements, and some specialising exclusively on one particular microhabitat. A remarkable 40% of woodland wildlife is dependent on this aspect of the forest ecosystem.
Britain’s primeval forest : Picture a rich forest-scape with lush undergrowth and trees of all ages, from tiny seedlings, to huge, gnarled giants, some of which are thousands of years old. The forest floor strewn with fallen limbs and trunks, the scents of fresh vegetation and decay mingling in the air. Dappled glade towards a large, rotting stump, full of grubs etc …
Most of our remaining woodland is very different from those prehistoric forests, and a key difference is the amount of standing and fallen dead wood in them. Studies in temperate forests in North America and elsewhere suggest that in a healthy, wild forest dead wood can comprise as much as 30% of the overall woody biomass. Today, the average British woodland has far less. Before examining why, let us look at the crucial role which dead wood plays within the forest ecosystem.
Dead trees and sun baked logs have become one of my favourite places to look for wildlife and insects and I am beginning to log (excuse the pun) the locations of all the dead wood / log habitats in my local area.