Masters research project
Thinning, pruning and clear-felling are common forest management activities in Irish plantation forests. The deadwood or “logging residues” produced by these management activities are currently left in situ after operations have ceased. Recent interest in the use of these residues as biofuel to counteract rising fossil fuel prices while curbing greenhouse gas emissions has led to their removal from commercial plantations in other parts of Europe. However, these woody debris piles, known as brashpiles, are important habitats for some forest-dwelling species, particularly fungus gnats.
Female fungus gnat Mycetophila vittipes (Diptera, Mycetophilidae)
This was the first study of the fungus gnat fauna utilizing Sitka spruce clear-fell and thinning debris in commercial plantations in Ireland. From June to September 2010, standard emergence traps used to collect emerging adult fungus gnats at four Sitka spruce plantations. 1794 fungus gnats from 80 different species were recorded, including two species that had never previously been recorded on the island of Ireland and two other species whose status in Ireland was previously uncertain. The gnat communities inhabiting debris from thinning and clear-felling were be distinct from one another, with suspected specialist species utilizing the more exposed brash habitats on clear-fell sites.
This study found that brash is an important substrate for fungus gnats in Ireland and compensates, at least in part, for the shortfall of deadwood in Irish plantations. It is therefore recommended that brash should be left in situ after clear-felling and thinning operations, to allow colonisation by fungi and, consequently, deadwood-specialist invertebrates.
- Deady, R. 2013. Four species of Mycetophilidae (Diptera) new to Ireland. Irish Naturalists' Journal, 32 (2):