Decoding carbon, water, and energy exchange driven by agricultural and horticultural intensification in semi-arid...

Terrestrial ecosystems play a vital role in sequestering carbon dioxide (CO₂); however, growing both agri-horticultural intensifications can influence CO₂ sequestration potential. This study was conducted in an agri-horticultural-intensive ecosystem of Central India to investigate the net ecosystem exchange (NEE) of CO₂, water (H₂O), and energy fluxes and assess the influence of meteorological factors using the eddy covariance datasets acquired from January to June 2024. The highest monthly mean diurnal CO₂ flux was recorded in January (-7.98 µmol m^-2 s^-1), and the lowest was in June (-3.03 µmol m^-2 s^-1), resulting in a cumulative CO₂ uptake of -94.5 g C m^-2 half-year^-1. Evapotranspiration (ET) over the January-to-June period was recorded at 273.3 mm, with sensible heat (H) dominating over latent heat (LE) flux, indicating water-stressed semi-arid ecosystem. Over the 6-month period, the ecosystem exhibited a net ecosystem exchange (NEE) of -177.59 g C m^-2 half-year^-1, a gross primary productivity (GPP) of 567.13 g C m^-2 half-year^-1, and an ecosystem respiration (Reco) of 389.54 g C m^-2 half-year^-1. Despite agri-horticultural intensification, the ecosystem functioned as a strong sink for atmospheric CO₂. The findings provide critical insights into carbon, water, and energy exchanges in agri-horticultural landscapes and are essential for understanding the market-driven agri-horticultural intensification and developing sustainable land restoration strategies to address groundwater depletion, climate vulnerability and ecosystem functioning.