Here is a post from a grower that may interest some readers:
As well as intentionally planted trees, our area in the Strzeleckis has a lot of blackwood growing as paddock trees, in roadside verges and so on.
I was clearing out some thistles and blackberries from the verge yesterday. Within about 20 metres along the side of the road I noticed 3 wild bee colonies. These were all Apis mellifera or European honeybee. Although not a native these insects do sterling work in pollination.
All 3 colonies were in hollows in blackwoods. One was in the upper section of a dead blackwood that had fallen over years ago, another was only a few metres away in a hollow of a half-dead blackwood and another was in the remaining trunk segment of a blackwood that had died a while ago and lost its crown and any side branches.
Interesting that all three bee colonies were using blackwood hollows. Some agroforestry commentators suggest leaving an occasional dead tree (if a stem dies or perhaps killed as part of thinning) to form a stag for habitat.
It’s an interesting story, if a bit marginal to what I’m trying to achieve.
Some random responses:
What other trees around where you were have hollows? I suspect mainly blackwoods.
Also blackwoods, once they die, quickly start to rot out, so they are a natural and ready source of hollows, if only short lived before the tree falls and rots entirely.
But I definitely take your point. Leaving dead trees AND logs is important for insect habitat. We humans are too quick to tidy up and leave the forest/road verge looking like a park, rather than a forest with all its litter and chaos – and insects.
What about in a blackwood plantation?
Trees randomly die and fall over. Should we leave a few as habitat? Or will this just build up insect populations that then attack living trees? I don’t know the answer. I suspect that insects that inhabit dead trees are different to those that attack living trees. Perhaps those that live in dead trees are predators of insects that attack living trees. Ultimately the answer will vary depending upon the inclinations of each land owner. Some will give some favour to habitat while others will go for maximum tidiness and “hygiene”.
Thanks for the story.