Abstract: The differences of rainfall redistribution and canopy leaching between the pure stands of Pinus massoniana and Castanopsis hystrix were compared to provide hydrological data for the transformations of coniferous plantations in southern subtropical China. In Guangxi Youyiguan Forest Ecosystem Research Station, a combination of field testing and laboratory analysis was used to measure rainfall, throughfall, and stemflow by 30 understory tipping bucket rain gauges from January to December in 2016. We analyzed the chemistry compositions in samples from ten rainfall events occurred during July to December. The results showed that precipitation was 1070.2 mm during study period. The throughfall reached 823.0 and 693.2 mm in pure stands of P. massoniana and C. hystrix, accounting for 76.9% and 64.8% of the precipitation, respectively. Moreover, the stemflow was 3.2 and 9.9 mm for both stands, being 0.3% and 0.9% of the precipitation, respectively. The canopy interceptions were 244.0 and 367.1 mm, accounting for 22.8% and 34.3% of the precipitation, respectively. Our results suggested that there were differences in the rainfall redistribution between the two pure stands, with C. hystrix stand having better ability of canopy interception than P. massonianastand. The amount of canopy leaching for K⁺, Mg²⁺, Na⁺ and Ca²⁺ in C. hystrix stand was 17.53 kg·hm^-2, which was 0.7 times of the P. massoniana stand. However, the acid buffering capacity of C. hystrixstand was 1.6 times of the P. massoniana stand. Compared with the P. massoniana pure stand, the C. hystrix pure stand was more effective to prevent canopy nutrient leaching and adapt to the acid deposition.

Key words: Drosophila melanogaster, protein expression, apoptosis, silver nanoparticles