The deadwood invertebrates
It’s apparent that a great deal of the articles on our blog seem to revolve around a single aspect of our work as rangers here at Trelissick. This oft-omitted subject – a source of great fascination, discussion and affection for our small countryside team – concerns the retention and protection of our dead and dying trees and the remarkable, obscure ecosystems that are entirely reliant on this twilight phase of the woodland cycle.
Within the woods at Trelissick, it is not difficult to spot substantial accumulations of deadwood that we have deliberately left in place. Organisms that feed upon this wood are called ‘saproxylic’ and a large proportion of those that are rare or threatened are often completely confined to this relict form of habitat. A great deal of these species have rigid requirements for their very existence and can only be found where management has made concessions for the continuity of mature trees and deadwood. You can find out more about this in our previous blog post here.
Trees that are dead or decaying play a crucial role in the functioning and fecundity of woodland ecosystems through their direct effect on biodiversity (the sheer number of different species present). Within a single such tree, crevices and rotting cavities fill with detritus and provide food and shelter for an enormous range of invertebrates such as scarce beetles, centipedes and wood lice. These insects in turn provide food for birds such as the tree creeper and lesser spotted woodpecker and bats such as the noctule. Furthermore, tree wounds and seepages (where rainwater gets into the sap) afford feeding sites for hornets, hoverflies and butterflies.
We would like to introduce you to a selection of these secretive creatures that we have here on the estate:
" ...within ye hear No sound so loud as when on curtain’d bier The death-watch tick is stifled."
The oak longhorn beetle often appears during the winter months in firewood when kept for several days in heated rooms so keep an eye out before putting logs in the fire! They are not, however, considered a danger to wood used in buildings because it has become too dry for their particular preferences.
Unfortunately, this beetle’s vivid claret colour may also have contributed to its scarcity. Many gardeners in the UK often assume any all-red beetle is a lily beetle (Lilioceris lilii) and often kill them.