Net Ecosystem CO₂ Exchange of a Subalpine Spruce Forest in Switzerland Over 26 Years: Effects of Phenology and Contributions of Abiotic Drivers at Daily Time Scales.

ABSTRACT: Climate change affects carbon sequestration dynamics and phenology in forests, especially in alpine and subalpine regions. Here, long-term trends in climate, net ecosystem CO₂ exchange (NEE), net carbon uptake period (CUP_net) and their drivers were investigated, using 26 years of flux measurements in a subalpine spruce forest (CH-Dav, Switzerland; 1997 to 2022). CUP_net length, start (SOS) and end of season (EOS) were extracted from smoothed daily NEE time series. We used machine learning to determine the importance of environmental drivers on daily NEE and CUP_net. Annual mean and maximum air temperatures (T_air) increased, while soil water content (SWC) decreased significantly between 1997 and 2022. Annual C sinks increased from 1997 to

SUBMITTER: Krebs L 

PROVIDER: S-EPMC12287681 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature