Effects of long‑term changes in aboveground litter input on soil microbial carbon use efficiency in a temperate forest of Changbai Mountain, Northeast China

Twelve 2 m × 2 m sample plots were randomly set up and subjected to three types of litter treatments: keeping the original litter on the surface unchanged (CK), removing surface litter (NL), and doubling surface litter (DL). Each treatment had four replicates, and to avoid edge effects and reduce the influence of the tree rhizosphere, the sample plots were at least 2 m away from the tree trunk.

CK treatment: natural state of litter; NL treatment: Remove surface litter from the soil in the sample plot, set up a litter collection net above the sample plot, and isolate litter; DL treatment: The litter collected from the NL treatment in the current year will be evenly scattered in the DL treated plot. From May to October each year, the litter collected from the NL plot will be evenly scattered in the DL plot every month.