Camellia oleifera is known as an aluminum (Al) hyper-accumulator, and the Al mainly accumulates
in its leaves. However, little is known regarding the accumulation of Al, the decomposition
of fallen leaves, and its effect on soil exchangeable Al contents, or ways to reduce Al contents in C.
oleifera leaves. In this study, litter bag and pot experiments were carried out to investigate Al accumulation
and decomposition of C. oleifera leaves, and the effects of lime and biochar applications
as soil amendments on leaf Al contents. Results showed that higher Al contents were observed in
older leaves. The highest Al content of fallen leaves was 15,748.62 mg kg-1. In the first 4 months,
28.73% of the total mass of fallen leaves had decomposed, while 35.64% of the Al was lost in the
first month, followed by 7.57% in the second and 4.15% in the third month, and leaf decomposition
significantly affected the soil exchangeable Al contents. The content of total non-crystalline Al
was highest, followed in descending order by organically bound Al, exchangeable Al, and watersoluble
Al in treated soils. The addition of biochar and lime as soil amendments had synergic
effects on reducing the Al contents of C. oleifera leaves, and they interactively influenced the exchangeable
Al and organically bound Al. These results indicate that the Al fixed in leaves that then
falls onto the soil is one of the important ways that C. oleifera alleviates Al toxicity, which can be
further improved by applying lime and biochar as soil amendments.