Differential home-field advantage in decomposition between surface and standing leaf litter on the Tibetan Plateau

Background: Climate change and human activities are shifting plant species distributions, relocating plant litter to new environments. The home-field advantage (HFA) is a phenomenon where litter decomposes more rapidly in its original habitat due to long-term co-adaptation between decomposer communities and litter quality. Despite its importance in carbon and nutrient cycling, it remains unclear how various litter types demonstrate differences in HFA beyond just surface leaf litter. Methods: Here we conducted a comprehensive 35-month transplant decomposition experiment on the Tibetan Plateau, using 630 litter bags across three typical ecosystems (Mesic meadow, Wet meadow, and Fen) to assess the HFA effects on the decomposition of surface and standing leaf litter. Results: Compared to surface leaf litter, the decomposition of standing leaf litter was slower, but it exhibited a stronger HFA effect across three ecosystems. Additionally, the HFA effect on litter decomposition varied across different ecosystems. In mesic and wet meadow ecosystems, standing leaf litter decomposition displayed a more pronounced positive HFA effect compared to surface leaf litter. Contrastingly, in fen ecosystems, surface leaf litter exhibited a positive HFA effect, while standing leaf litter demonstrated a negative HFA effect. The differing HFA effects between surface and standing leaf litter were primarily driven by variations in litter quality and the hydrological conditions of the respective ecosystems. Conclusions: These findings suggest that the HFA in decomposition differed between surface and standing leaf litter and highlight future studies should consider different litter types when predicting the carbon cycle of ecosystems.