Abstract ID: 3.12955 | Accepted as Talk | Talk/Oral | TBA | TBA

The Earth Critical Zone comprises the continuum of weathering material, soil, vegetation, microbiota, water and lower atmosphere, where fundamental physical, chemical and biological processes occur. Here photosynthesis and respiration play a crucial role in determining the exchange of carbon and water with the atmosphere and, in turn, water fluxes can affect plant species survival. Climate change impacts, especially in high-elevation habitats, could alter this balance, leading to shifts in plant communities’ composition, and potentially turning ecosystems from carbon sinks to sources. As such, understanding and modelling the relationship between fluxes, vegetation, and environmental factors in climate-threatened natural environments with a multi-faceted approach is crucial. This study investigates the relationship between CO2 and water fluxes with plants, soil and atmosphere in a climate change driven evolving ecosystem, in the Northern Apennines site of the GLORIA network. Data on Net Ecosystem Exchange (NEE), Ecosystem Respiration (ER), Gross Primary Production (GPP), and Evapotranspiration (ET) were collected in a high elevation grassland with portable dynamic flux chambers and an infrared gas analyser during the summers of 2024 and 2025. Flux measurements focused on homogeneous patches of the four most dominant plant species (thirty replicates per species in three different time periods), with simultaneous measurement of soil and environmental variables to statistically relate flux measurements to the potential environmental and climatic control variables. Plant species abundance changes data were obtained from the GLORIA network. Preliminary results show a positive relation between evapotranspiration and GPP with solar radiation and soil water content. Evapotranspiration differs significantly between plant species and aspects, while GPP were more similar between plant species, although with different seasonal dynamics. These preliminary results reveal a complex relationship among plant species, fluxes and environmental variables, enhancing our understanding of the fine-scale variability of carbon fluxes and evapotranspiration in high-elevation habitats. These data will facilitate the development of empirical models to project the impacts of future climate change scenarios on carbon storage, water fluxes, and vegetation dynamics. This study is part of the SENTINEL project (The reSponsEs of italian mouNTaIN Ecosystems to cLimate change), funded by MUR.