Adapting to climate change – a major challenge for forests

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Climate change means that trees germinating today will be living in a much-altered climate by the time they reach middle age. The expected changes are likely to hit them hard and threaten key forest functions in the decades ahead. However, appropriate management shall enable to increase the forest habitat's adaptability. This is shown by the results of the Forests and Climate Change research programme conducted by the Swiss Federal Office for the Environment FOEN and the Swiss Federal Institute for Forest, Snow and Landscape Research WSL since 2009.

Climate change means that trees germinating today will be living in a much-altered climate by the time they reach middle age. The expected changes are likely to hit them hard and threaten key forest functions in the decades ahead. However, appropriate management shall enable to increase the forest habitat's adaptability. This is shown by the results of the Forests and Climate Change research programme conducted by the Swiss Federal Office for the Environment FOEN and the Swiss Federal Institute for Forest, Snow and Landscape Research WSL since 2009.

Climate change is happening so quickly that a question mark hangs over whether forests can adapt accordingly without human interference and can continue to perform their various functions such as timber production, protection against natural hazards and providing a recreational space for the public. In Switzerland, temperatures have already risen by around 1.9°C since the beginning of industrialisation. Even keeping global warming down to the 1.5-2°C target set by the Paris Agreement on climate change will yield a further increase of 1-2°C.

For the Swiss forests, this warming trend will involve vegetation zones shifting 500‑700 metres higher in altitude. Thus, in future, broadleaf trees will increasingly thrive in lower-lying mountain forests which are currently dominated by conifers. Rising temperatures and drought levels during the growing season are exerting stress on trees and are increasing the risk of forest fires and exacerbating attacks by harmful organisms. This affects Norway spruce, for example, which is more susceptible to bark beetle infestation in prolonged dry spells. In future, it will be less common at lower elevations, while the conditions will be increasingly favourable to more drought-tolerant species such as the sessile oak.

Continue reading at Swiss Federal Institute for Forest, Snow and Landscape Research WSL

Image Credit: Peter Brang (WSL)