Long-term successive rotation affects soil microbial resource limitation and carbon use efficiency in Chinese fir (Cunninghamia lanceolata) monoculture plantations

•Long-term successive rotation of Chinese fir deceased litter and soil quality.•Successive rotation increased C:N imbalance between soil microbes and resources.•Successive rotation aggravated microbial C limitation and increased its CUE.•Litter and soil stoichiometry were key drivers of microbial CUE and activity.