Using Springs as Sentinels of Climate Change in Nature Parks North and South of the Alps: A Critical Evaluation of Methodological Aspects and Recommendations for Long-Term Monitoring

Spring ecosystems are diverse transition zones between ground- and surface-water habitats. Due to their characteristics and vulnerable species assemblages, springs are considered indicator systems for monitoring environmental change. In particular, climate change is expected to alter spring-ecosystem features, such as water temperature and discharge, affecting otherwise typically stable biotic and abiotic conditions. However, reliable trend-development recognition and analysis require a uniform methodology and comparable data series over long periods of time. Spring research findings in the Berchtesgaden National Park and the Adamello-Brenta Nature Park have been consolidated to develop methodological recommendations to create lasting societal-added value. The successful transfer of the methodology to the Bavarian Forest National Park and the experienced contribution of the Bavarian Association for the Protection of Nature (Bavarian Climate Alliance) strongly improved method validations. Our resulting, newly developed recommendations for long-term spring monitoring have a focus on climate change impacts and aim at providing a decision-making basis for establishing programs in similar ecological and climatic zones. Uniform site-selection criteria and selected climate-sensitive parameters are indicated. This includes documenting the spring's environment and structure, measuring abiotic parameters, and determining selected floristic and faunistic groups. We recommend measurement and sampling-survey intervals ranging from 3(4) times yearly to every 5 years, depending on the parameter. We further suggest a database system that integrates all monitoring parameters to ensure consistent data management and storage. Analysing the data resulting from our new holistic spring monitoring methodology should provide critical knowledge about putatively changing ecosystems that can then be used as evidence of climate-change impact on spring ecosystems.