Fig. 1: Selected testing site with grid
Conflicts of interests? Beetles vs Spruce.
Several decades have gone by since the great reforestation after World War II, when Central Europe planted thousands of spruce plantations – fast in growth, easy to maintain, straight and slender, perfect for industrial processing. Today we are facing a different kind of catastrophe to deal with: climate change. This change is not happening as slowly, as one might perceive subjectively, but is already forcing forestry industries to adapt. With changes in the climate, the forests change along. Alien species are benefiting from the momentum and find conditions which let them thrive with more success than some of their native neighbor-species – they become ‘invasive’. One of these invasive species is the bark-beetle. Feared and hated by those whose incomespan depends on the timber market, bark-beetles eat away the cambrian, the life-sustaining nutrient-transfer-system of the trees, and lay their eggs underneath the bark. There are many kind of bark-beetles, with the two most ‘invasive’ ones in Europe being the European spruce bark-beetle (Ips typographus) and the six-toothed spruce bark beetle (Pityogenes chalcographus).
It is easier for the bark-beetle to drill its way through the bark when the tree is already in bad condition prior to its visit, weakened by drought and heat caused by climate change. The result of such a mass-landfall of a bark-beetle-invasion is a massive decrease in timber-worth (not only is the wood from lesser quality once infested, but also the increase in timber availability after a beetle-feast will lower the market price of non-beetle-wood) – at least this is how the story goes from a very anthropocentric way of storytelling. But if we look into the further effects caused by the bark-beetles incursion, a different story enfolds:
Anthropogenic spruce woods harbor low biodiversity and thus bear low resilience. Similar to forest fires, bark-beetles are functioning as a kickstarter for forest-rejuvenation and enabling a biodiversity-regrowth by resetting the conditions for all species. If we allow the beetles to do their job and don’t replant with (only) spruce again (or stop planting altogether), a phase of rapid succession will follow with new species emerging from the rotting spruce. The deadfall of the spruce monoculture will nurture other bugs and critters, vertical deadwood providing niche habitats for mammals and birds of prey. Only a couple of years after a bark-beetle-invasion a forest can look and function completely different. If we let them. If we welcome the ‘invasive’ species as aiders through the crises of the Anthropocene. Let them destroy our old structures and rules. Let there be succession and diversity again. Let us welcome the aliens.