UV-B辐射对香樟凋落叶化学组成和分解的影响

Effect of UV-B Radiation on Chemical Composition and Subsequent Decomposition of Leaf Litter of Cinnamomum camphora

采用模拟UV-B辐射增强方法研究了UV-B辐射香樟(Cinnamanun camphora)叶片化学组成及其凋落后分解和养分释放的影响。结果表明:UV-B辐射增强导致香樟凋落叶中的N、P、K和C含量分别比对照组显著减少了36.0%、14.3%、42.7%和7.4%(p<0.05),致使凋落叶中的C:N、木质素:N和C:P比分别显著增加了44.7%、77.1%和7.3%(P<0.05),木质素含量显著增加13.3%;在之后1 a分解过程中,生长期间接受增强UV-B辐射的凋落叶分解的更快,但与对照组差异不显著(P>0.05)。

An experiment was carried out on the effects of UV-B radiation on leaf litter chemical composition and subsequent decomposition in humid subtropical forest systems. The leaf litter was derived from Cinnamornum camphora seedlings exposed to elevated and ambient ultraviolet B （UV-B） radiation treatments during growth for one year. The results showed that UV-B treatment significantly decreased the original N, P, K and C content in leaf litter by 36.0%, 14.3%, 42.7% and 7.4%, and increased the ratios of C：N, lignin：N and C：P in leaf litter by 44.7%, 77.1% and 7.3%. The decomposition of leaf litter derived from seedlings exposed to elevated UV-B treatment during growth was faster, but did not show significant difference with that of the control.