CLAIMES

Alpine mountain lakes are considered as jewels of the mountain world. In the light of climate change, drastic ecological changes of these lakes are expected. The ecological functions of mountain lakes are closely linked to their contributions to human well-being: the so-called ecosystem services (ES). For example, natural mountain lakes are often destinations for outdoor recreationists but can also supply water for agriculture. To preserve both the ecosystems of mountain lakes and their ES in the future, gaining knowledge about possible consequences of ecological changes due to climate change and a potential increase of human use is important. In this context, the CLAIMES project compares a larger number of mountain lakes in the northern (Niedere Tauern, Austria) and the southern part of the Alps (South Tyrol, Italy), which are long-term monitored.

The first step is to analyze the response of mountain lakes to climate change within the last 20 years. For this purpose, (1) temperature trends will be calculated, (2) plankton organisms (such as bacteria and algae) and fish will be detected using modern DNA-based methods, and further (3) indicator organisms will be collected. These data will be compared with older measurement data and can, thus, provide information on the resilience of mountain lakes under climate change.

In a second step, ES will be collected for different lake types. The lake types studied are based on the UN criteria for sustainable development, such as access to clean water, intensity of use or climate-related sensitivity. Provisioning and regulating ES (e.g., water supply, water regulation, and water quality) are assessed with the help of statistical data, limnological measurement data, and modelling. Cultural ES (e.g., outdoor recreation) are recorded by means of geotagging or surveys. Based on IPCC climate scenarios, validated temperature models will provide information on the extent to which the expected ecological changes in the mountain lakes can also affect their ES.

In the third step, the current use of different mountain will be evaluated comparatively. For this purpose, (1) the relevant ES will be determined, (2) the ES will be weighed against each other with the help of surveys, and (3) indicators for the relevant ES must be defined. The ES will be evaluated under different climate scenarios. Finally, proposals for environmental policy instruments will be developed and presented with the aim of ensuring the sustainable use of mountain lakes in the future.