Effects of exotic detritus input on native litter breakdown in a eutrophic lake: investigating the home-field advantage

Invasive plants have been shown to alter ecosystem functions. However, there is limited information available on the effect of the invasive species litter input on native litter decomposition and home-field advantage (HFA, increased decomposition at a home environment compared to a guest environment). To investigate this, we conducted a field experiment using leaves of native Trapa natans and Typha orientalis with and without invasive species Alternanthera philoxeroides and then incubated them at T. natans and T. orientalis habitats in a eutrophic lake for 50 days. In control and treatment, the decomposition and N release rate of T. natans were significantly higher than that in T. orientalis species litter at two habitats, indicating no HFA occurrence. A. philoxeroides litter input promoted the decomposition and N decay rate of T. orientalis, not T. natans. The mean decomposition rate of T. orientalis in control and treatment were 0.0138 and 0.0342 day⁻¹; for T. natans, it was 0.0703 and 0.0754 day⁻¹, respectively. The mean N decay rate of T. orientalis in control and treatment were 0.0235 and 0.0468 day⁻¹; for T. natans, it was 0.0511 and 0.0544 day⁻¹, respectively. Invasive species presence increased microbial respiration rate of T. orientalis, but not for T. natans species litter in two habitats. These results suggested that A. philoxeroides litter input accelerated low quality litter decomposition though increased microbial activity. However, it did not influence the HFA performance, which may be closely related to the lake eutrophication.