Abstract: The decomposition of plant litter in peatland is a key process in the ecosystem carbon cycle. The rate of litter decomposition and its underlying mechanisms significantly influence the biogeochemical cycling of peatland ecosystems. Litter decomposition is a complex process governed by the interactions of multiple factors, and increasing research efforts have focused on the effects of both biotic and abiotic factors on this process. Microorganisms, as the primary decomposers of soil organic matter, play an important role in the decomposition of plant litter, which is characterized by their phased and unequal contributions to the process. Additionally, microbial activities influence organic matter decomposition through functional genes encoding key enzymes. Beyond microorganisms, other biotic factors, including litter quality, plant community composition, and soil fauna, along with abiotic factors such as temperature, moisture, and light, significantly impact litter decomposition and microbial community. This study provides a comprehensive review of the litter decomposition process in peatlands, elucidating the roles of microorganisms and soil enzymes, as well as the regulatory mechanisms by which biotic and abiotic factors influence litter degradation and microbial community composition. These insights provide a better understanding of peatland carbon cycling and conservation, ultimately contribute to climate change mitigation. Future research should further associate aboveground and belowground systems to explore the interactions among plants, microorganisms, and soil environments, enabling a more comprehensive understanding and effective conservation of peatland wetland ecosystems.

Key words: peatland, plant litter decomposition, carbon cycle, microorganism, functional gene, soil enzyme