soil

Over a year staring from October 2023, samples were collected at three-month intervals. Soil samples were collected using a stratified random sampling method. Five sampling points were established within each plot, and samples were taken according to soil layer depth (0-10 cm, 10-20 cm, 20-40 cm). After removing stones, roots, and litter, samples from the same layer were mixed by quartering, and 500 g soil samples were packaged. A total of 144 soil samples were collected throughout the year. Litter and fine root samples were collected centered around the standard trees. Within a 50 cm radius, three 20 cm * 20 cm quadrats were established to collect undecomposed and semi-decomposed litter, and fine roots (diameter < 2 mm) from each soil layer were sampled. After mixing within quadrats, samples were packaged separately, resulting in a yearly total of 96 litter samples and 192 fine root samples.