Peter Hasted, Managing Director of Thanet Urban Forest
A day to remember and a lesson learnt about the catastrophic impact of the European spruce bark beetle.
I’m Peter Hasted and, as the Managing Director of Thanet Urban Forest, I am working to re-green Great Britain by planting trees across the Isle of Thanet and beyond.
Anyone who knows me will tell you just how passionate I am about trees and the importance of caring for and investing in our environment. However, on 7th August this year during a family holiday to Latvia I had a forest experience of a quite different and completely unforgettable kind.
Our day began promisingly, with my partner surprising me and the children by taking us to the Latvian National Forest Nature Park in Tērvete, which is one of the most popular tourist and family-friendly places in Latvia. That morning there was only a 40% chance of rain showers so we decided to pack some waterproofs to enjoy a potentially wet woodland walk. After parking up and paying entrance fees, we walked along the main track into the forest and the sun danced and glistened on the tall, slender silver birch growing in between spruce as we stopped to read the tales of the mythical forest creatures and admire the carvings of toadstools and dwarfs.
As we ventured deeper into the forest, the cloud came over and the sky began to darken and rumble. The forest continued to darken and the rumbling persisted as the air thickened and an unnerving atmosphere developed along the forest floor.
The aftermath of the storm.
Trees snapped like matchsticks
Moments later the wind swirled like a squall and before our eyes, like some divine interference, the forest canopy literally split apart, exposing the biggest, darkest swirl of clouds ever imaginable and the rain began to fall. The children clambered into one of the many tiny gnome lodges along our route to escape the elements. Then, hearing an almighty crack, I spun round to witness a 20-metre crown fall 20 metres to the forest floor. Fearing any trees could potentially fall onto the miniature lodge, we abandoned the structure and found a small clearing along the path. We huddled together watching the canopy flail in the wind as the mature spruces continued to snap like matchsticks, ready to react if any of the trees above our heads started to fall in our direction.
The cracking of branches increased and root plates were torn up from the soil as 40-metre trees fell all around us, blocking paths and terrifying us all. What might otherwise have been an interesting and exciting experience for an arborist became a living nightmare as I didn’t know how best to protect my family – watching the tree crowns above being battered by the extreme weather, fearing that the next crack could be disastrous. We shielded the children while the rain hammered down for what seemed like an eternity. In fact, it was less than ten minutes!
As soon as the winds began to ease, we all ran back along the now unrecognisable path we had walked along just minutes before. Dodging branches and climbing over fallen trees, we discovered a tree had crushed the climbing frame the children had previously been playing on!
Taking sanctuary in one of the educational timber lodges as we dried off, we talked to one of the woodsmen who told us how he could now see daylight through the canopy which hadn’t been possible half an hour before. He said it was a once-in-100-years storm.
For me, it certainly felt like a once in a lifetime experience, and one I wouldn’t wish on any other parent. Thankfully, on this occasion, we all walked out of the woodland unscathed. But I certainly have a greater insight into the potential dangers posed by extreme localised weather events as they increasingly imperil the cherished natural environment we hold dear.
Galleries made by European spruce bark beetle. (Photo: Petr Kapitola, Central Institute for Supervising and Testing in Agriculture, Bugwood.org)
The impact of a spruce bark beetle
Following the experience, I was interested to discover that a pre-existing European spruce bark beetle (Ips typographus) infestation could have compounded the damage caused by the storm. The forest management team have been actively controlling the beetle since 2019.
The following information about the pest is from Forest Research’s website (see link below). The beetle seems to prefer dead, stressed or weakened trees, but under the right conditions I. typographus can greatly weaken and ultimately kill the spruce (Picea spp.) trees that make up a great proportion of Tērvete forest, thereby making them more susceptible to storm damage and other stressors, such as wildfires. It is better known in the UK as the larger eight-toothed European spruce bark beetle but has other common names too, including bark beetle, eight-dentate beetle, engraver beetle, eight-spined beetle and spruce bark beetle. A breeding population was discovered in Kent in December 2018 and is currently subject to statutory eradication action.
Forest Research’s website says: ‘Most species of spruce are susceptible to attack by eight-toothed spruce bark beetles, and the widespread presence of Norway spruce in continental Europe means it is the most affected species. The beetles have, however, been observed on other conifer tree species, including fir trees (Abies species), pines (Pinus species) and larches (Larix species).
‘Larger eight-toothed European spruce bark beetles are often associated with windblown, damaged and recently-felled spruce trees, where they build up numbers before moving on to attack adjacent live trees. Inspection of trees in this category should therefore be a priority.
‘Look also for individual dead trees, or groups of them. The latter arise when the beetles “mass-attack” trees, overcoming the trees’ usual defences by a combination of large numbers and blue-stain fungus. This phase can lead to extensive tree deaths.
‘If a tree is infested with eight-toothed spruce bark beetle, inspection of the bark, and the wood under the bark, should reveal a linear gallery system, where the females lay their eggs.
‘Larval galleries radiate outward from these linear galleries, becoming wider as the larvae grow as they burrow along. This gallery pattern is unique to this species, and can therefore be relied upon as an indicator of its presence. However, the pattern might not always be as easy to discern as the above description and the picture imply, so any variation should be treated with suspicion and investigated further. Ips beetles are often referred to as “engraver” beetles because of the “engraved” appearance of the galleries.’
If you think you have seen the beetle, the sighting must be reported immediately to the plant health authorities using TreeAlert in Great Britain or TreeCheck in Northern Ireland and Ireland.
As my family and I almost learnt to our cost, the combination of an overwhelming infestation and an extreme weather event can not only prove catastrophic for a forest but also pose a potentially deadly threat to human life.
Peter and his family in the calm before the storm.
For more information
Forest Research. Larger eight-toothed European spruce bark beetle (Ips typographus). www.bit.ly/46NyFY4
Mammadaba, Latvia. LVM nature park in Tērvete is temporarily closed due to storm damage. www.bit.ly/3F3rChz
Mammadaba, Latvia. ‘Mischiefs’ of European spruce bark beetle at LVM Nature Park in Tērvete. www.bit.ly/3ZIyQkz
All websites accessed 31/10/2023
This article was taken from Issue 203 Winter 2023 of the ARB Magazine, which is available to view free to members by simply logging in to the website and viewing your profile area.