Abstract:In order to understand the effects of precipitation pattern on litter-fall in lower subtropical evergreen broad-leaved forest, a field precipitation manipulation experiment at Heshan National Forest Research Station (Guangdong Province, China) was designed to simulate decreasing dry-season (October-March) and spring (April-May) rainfall and the litter-fall respones in the forest was studied. The results showed that annual litter-fall of the experimental forest was 9.24 t hm-2, of which leaf litter was the main composition at different stages, accounting for 50.7%-69.3% of the total. The decreasing dry-season rainfall (DD) treatment significantly reduced leaf litter production (P<0.01). The whole-year litter production was also reduced by 10.3% under the DD treatment compared to the control, but not statistically significant. Decreasing spring rainfall (ED) also reduced flower-, fruit-, and leaf-litter as well as the total during the spring time, but the whole-year litter production was increased by 11.3% compared to the control. No statistically significant difference of ED effects on the spring and wholeyear litter production was found. Neither DD nor ED treatments had obvious impacts on the quality of leaf litter, but DD treatment significantly reduced lignin content in leaf litter of Michelia macclurei (P<0.05). Therefore, the changes in precipitation pattern could influence the soil carbon sink in the lower subtropical forests of China.
