Carbon in Permafrost Experimental Heating Research (CiPEHR) site (PRJCA046575)
We conducted depth-stratified sampling across seven soil layers (0-5 cm, 5-15 cm, 15-25 cm, 25-35 cm, 35-45 cm, 45-55 cm, and 55-65 cm) from 9-year winter warming plots at the Carbon in Permafrost Experimental Heating Research (CiPEHR) site in Alaska's discontinuous permafrost region established in 2008. Employing 1.5 m * 8 m snow fences for winter insulation, this experimental design elevates year-round tundra soil temperatures including unprecedented deep-soil warming. By integrating depth-resolved microbial taxonomy (16S rRNA sequencing) and physicochemical analyses, as well as whole-profile measurements of CH4 flux and ecosystem respiration during the growing season in 2017 (May to September), we quantified: (1) long-term warming effects on EM/C, and (2) depth-dependent controls governing EM/C variability.