The role of light on litter degradation in different ecosystems

Background and aims Plant litter decomposition was long thought to be governed by biological processes, yet growing evidence highlights solar radiation as a critical driver with ecosystem-specific variations. Existing research remains fragmented, lacking systematic integration of how light drive litter decomposition within ecosystem types, and what factors modulate the driven force on litter decomposition. Methods To address above scientific gaps, we retrieved literatures published between 1998 and 2025 from Web of Science, PubMed, and CNKI using Boolean keywords to employ a meta-analysis. Of 4,203 retrieved literatures, we integrated 2,062 data from 53 global studies to systematically investigate the driven force and affecting factors on the force across diverse ecosystems. Results Full-spectrum light increased litter mass loss by 25.4% on average. Ultraviolet, blue, and green light showed comparable effects in early stages, while blue light exerted the strongest effect in the late decomposition stage. In terrestrial ecosystems, arid/semi-arid ecosystems (deserts, grasslands) exhibited the strongest photodegradation contributed about 51.5% mass loss in a year, mainly driven by light due to limited microbial activity. In the forest, photodegradation accelerated about 15.5% mass loss throughout the year. Aquatic and wetland ecosystems showed 50–60% mass loss enhancement. MAP (mean annual precipitation) was the most influential climatic factor. Lignin content was positively correlated with photodegradation, while carbon content showed a negative correlation. Conclusions Our meta-analysis confirms that sunlight significantly drives decomposition regulated by climatic variables and litter properties.