Abstract:

The leaf litter decomposition of six representative tree species, Cunninghamia lanceolata, Pinus massoniana, Schima superba, Cinnamomum camphora, Cyclobalanopsis glauca and Castanopsis eyeri, in subtropical region was investigated with litterbag method under ambient and reduced ultraviolet-B (UV-B) radiation (22.1% below ambient) treatments. The results showed that there were differences in litter mass remaining rates of each species under two UV-B radiation treatments, except for a few decay stages during decomposition, and the difference became more obvious with decay time. The reduced UV-B significantly decreased the litter decomposition rates of six species by an extent from 33.3% for C. camphora to 69.6% for C. lanceolata (P<0.01). Both UV-B radiation treatment and litter type significantly affected litter decomposition rate (P<0.001), with a stronger effect of UV-B radiation than litter type. There were significantly negative correlations between decomposition rate and C:N ratio of leaf litter under both ambient and reduced UV-B radiation treatments (P<0.05).

Key words: leaf litter decomposition, UV-B radiation, subtropical region, photodegradation, leaching