Carbon dioxide exchanges in an alpine tundra ecosystem (Gran Paradiso National Park, Italy): A comparison of results from different measurement and modelling approaches

• DOI: 10.1016/j.atmosenv.2023.119758
• Publication Date: 2023-04-18T08:15:53Z
• Authors: Gianna Vivaldo; Marta Magnani; Ilaria Baneschi; Maria Virginia Bo...; Maurizio Catania; Mariasilvia Giamb...; Angelica Parisi; Brunella Raco; Antonello Provenzale
• Keywords: Ecosystem respiration; Biogeochemical Cycle

Mountain ecosystems are particularly sensitive to the effects of climate change and require a detailed understanding how their components respond varying environmental conditions. However, knowledge crucial biogeochemical variables, such as carbon dioxide (CO2) fluxes in Critical Zone high-altitude grassland Alpine tundra, is still patchy. In this framework, two methods typically adopted measure CO2 exchanges between atmosphere underlying ecosystem: eddy covariance accumulation chambers. Potential drawbacks affect both approaches, also depending on scale at which studies performed. On one hand, method provides large spatial coverage, despite requiring specific statistical assumptions that not always valid remote environments. addition, allows measuring only net ecosystem exchange (NEE), while separation emission (ecosystem respiration, ER) uptake (gross primary production, GPP), needed for functioning its possible future changes, requires partitioning procedures based regressive models. other chambers allow direct measurements NEE ER but usually limited sampling small areas themselves could potentially disturb plant-soil dynamics. The present study investigates issues by combining three complementary (i.e., covariance, portable automated chambers) summer soil-vegetation-atmosphere interface heavily instrumented tundra site. While chamber provide consistent estimates NEE, significant discrepancy results different methodologies was found daytime ER. particular, nighttime failed representing scale. modelled measured suggests processes involved during day night, fully represented These aspects would further explorations achieve site-specific assessments