Context

The densely populated River Lavant valley region in the eastern part of Carinthia in the southern Austrian Alps is characterised by a low level of precipitation, geological conditions unfavourable to groundwater storage and a limited number of springs that can be used for water supply.

In the past decades, annual precipitation amounts have declined significantly, and the region has been affected by water shortages during hot summers several times. Despite uncertainties in projections of future changes of regional precipitation patterns, the variability of groundwater levels and discharges of springs are expected to increase further in the future, raising the risk of water scarcity and temporal bottlenecks in water supply during drought periods.

Forests cover up to 50% of the region’s area, and in particular forest stands at mountain slopes fulfil important water retention functions and protective functions with regard to natural hazards.

The initiative

Among the different adaptation measures to secure future water supply on the regional and the local level, the project aimed to adapt the management practices in the forest sector in order to reduce vulnerability of regional forests to climate change, such as water stress, heat intolerance, bark beetle infestations, and susceptibility to storm damage, and to maintain or improve the protective functions (flood retention, slope stabilisation) and water storage capacities of forest ecosystems.

Silvicultural management aims to reduce the climate vulnerability of the region’s forests by promoting use of more drought-tolerant tree species and establishing more climate-resilient mixed forest stands. Due to extensive introduction in altitudes below 900 m in the past, Norway spruce is distributed far beyond its natural range and is by far the dominant tree species in the region.

To maintain and restore both the productive and non-productive functions of forests, adaptation measures focus on adjusting the tree species composition by replacing highly vulnerable Norway spruce trees with other autochthonous tree species that are better adapted to the changes in local climatic site conditions.

Results, limits and enable factors

Forest cover on hillsides and mountain slopes has strong effects on reduction of surface water run-off, thus contributing significantly to groundwater renewal and to decreasing the build-up of floods.
An intended co-benefit of re-establishing healthy and stable forests that are well adapted to current and future climatic conditions is maintenance and improvement of the delivery of their ecosystem services, in particular those related to the water retention and storage capacities of forest ecosystems.