LUCSES

Ongoing abandonment of mountain meadows leads to their shrub-encroachment and thus to functional changes. These changes affect the species composition, the water balance, but also the nutrient balance and thus the services of the mountain meadows for us humans: the ecosystem services (ES). Within previous common international projects, researcher involved in LUCSES were already able to identify important ES of mountain grasslands and to model these from the past to the future. Characteristic plant traits such as leaf area, nitrogen- and carbon content of the leafs as well as soil traits such as total nitrogen content and soil organic matter (SOM) are successfully used as indicators of ES (e.g., carbon storage, soil fertility, soil stability,...). As part of the LUCSES project, the characteristics of shrubs will now be incorporated into this trait-based approach. The core hypothesis of LUCSES is that shrub colonization results in a tipping point in relationships between traits and processes of nitrogen- and water cycling, and that this change can be related to characteristic plant traits and to mycorrhizal functions. For the first time, functional implication of mycorrhization, which especially in cold and nutrient-poor mountain regions contributes significantly to the nutrient- and the water supply, is also included in this type of trait-based approach. Within LUCSES, a large number of experimental plots with gradual shrub-encroachment are investigated in two study areas in the Alps (Lautaret, FRA and Stubaital, AUT), covering a broad range of grassland types and shrub species. A distinct experiment with small lysimeters analyses the effects of climate change (i.e. earlier snowmelt and drought in summer), linking involved biogeochemical cycles (i.e. nitrogen and water). LUCSES thereby also targets towards differences between summer and evergreen shrubs and to determine changes in the degree and type of mycorrhization. On the one hand, LUCSES provides an unprecedented database of plant characteristics for dwarf shrubs and, on the other hand, the prerequisites for the calculation of ecosystem functions and ecosystem services of shrub ecosystems over a wide range of succession stages. The combination of nitrogen and water balance with the quality and quantity of mycorrhization is a research frontier and leads to a better functional understanding and thus providing fundamental knowledge in alpine plant ecology. Results of LUCSES are published on the one hand scientifically, but on the other hand passed on the concept of ecosystem services to decision makers and practitioners within existing communication networks of the involved research institutions LECA Grenoble (Laboratoire d`Ecologie Alpine) and UIBK (University of Innsbruck).