The observable significant rise in temperatures in the Alps has seen the growing period getting longer and the forest line moving upwards. By the year 2100, under conservative scenarios, it might be another 400 metres higher; the species composition will also change. In addition to increased storm damage, climate change will also allow pests to advance to higher altitudes. What has for years been the reality in other parts of Europe is now also becoming visible in many places in the Alps: in South Tyrol/I, for example, the great danger posed by the bark beetle to forests that protect settlements from avalanches was highlighted this year, while in East Tyrol/A, 3.2 million cubic metres of wood were damaged, fifteen times the amount in a normal year; and in 2019 the Auvergne-Rhône-Alpes region was particularly hard hit.

The forestry industry relies heavily on fast-growing spruce – and it is precisely this form of monoculture that makes a ready meal for the European spruce bark beetle. Here, instead of the usual two to three generations a year, as many as four can now be observed. The brood of one female can result in 100,000 to 250,000 offspring in just one growing period. In addition, drought puts a strain on the trees as they cannot create enough protective resin.

The bark beetle is particularly problematic where it collides with the interests of commercial forestry. In protected areas such as the Berchtesgaden National Park, on the other hand, it is seen as helpful in the conversion to a healthy mixed mountain forest, which is richer in species and is even better at performing the protective forest function over the long term. Although the economic damage done to forestry is currently immense, the hope remains that the “forest's midwife” can help bring about mountain forests that are fit to face climate change. This also requires the backing of far-sighted forest managers.

Sources and further information:

www.ecologie.gouv.fr/impacts-du-changement-climatique-montagne-et-glaciers (fr), https://cittaclima.it/approfondimenti/montagna-e-clima/ (it), www.zamg.ac.at/cms/de/klima/informationsportal-klimawandel/klimazukunft/alpenraum (de), www.wsl.ch/en/news/2022/05/is-climate-change-raising-the-forest-line.html (en, de, fr, it), https://lwf.bayern.de/mam/cms04/boden-klima/dateien/a71-wo-der-wald-an-grenzen-stoesst.pdf (de), Bässler, C., Hothorn, T., Brandl, B., Müller, J., 2013. Insects overshoot the expected upslope shift caused by climate warming. (en). www.suedtirolnews.it/chronik/borkenkaefer-bedroht-immer-mehr-die-waelder (de), www.dolomitenstadt.at/2022/08/03/220-mio-borkenkaefer-gingen-in-osttirol-in-die-falle/ (de), www.onf.fr/onf/recherche/+/2bc::epidemie-de-scolytes-dans-le-nord-est-de-la-france-quelles-consequences-en-auvergne-rhone-alpes.html (fr), Seidl, R., Müller, J., Hothorn, T., Bässler, C., Heurich, M., Kautz, M., 2016. Small beetle, large-scale drivers: How regional and landscape factors affect outbreaks of the European spruce bark beetle. Journal of Applied Ecology 53, 530–540 (en), www.forstpraxis.de/kleines-einmaleins-des-borkenkaefers-20505 (de), www.berchtesgaden.de/nationalpark/pflanzen-tiere/tiere/borkenaefer (de), Beudert, B., Bässler, C., Thorn, S., Noss, R., Schröder, B., Dieffenbach-Fries, H., Foullois, N., Müller, J., 2015. Bark beetles increase biodiversity while maintaining drinking water quality. Conservation Letters 8, 272-281 (en), www.bund-naturschutz.de/ueber-uns/erfolge-niederlagen/nationalpark-bayerischer-wald/borkenkaefer-im-nationalpark (de), www.swissinfo.ch/eng/switzerland-s-forests-of-the-future-/47628176 (en, de, fr, it), www.nationalpark-bayerischer-wald.bayern.de/service/downloads/doc/broschuere/forschungsbroschuere_ba.pdf (de), www.bund-naturschutz.de/ueber-uns/erfolge-niederlagen/nationalpark-bayerischer-wald/borkenkaefer-im-nationalpark (de)