摘要
Rapid litter turnover in tropical forests and during summer seasons might be due to increases in ligninolytic enzyme activities during warmer periods.We compared ligninolytic enzyme activity[lignin peroxidase(LiP),manganese peroxidase(MnP),and laccase(Lac)]in the organic layers of forest soils across a global climate gradient.As expected,MnP activities in fresh litter layers increased with increasing air temperature.Litter Mn/lignin ratios correlate positively with MnP activity and more rapid litter turnover in warmer climates.In contrast,LiP and Lac activities are regulated by site-specific conditions.Lac activity is commonly observed in less acidic fresh litter layers,while LiP activity localizes in acidified and lignin-rich deeper organic layers.The widespread occurrence of MnP and an increase in MnP activities in warmer climates support efficient lignin degradation in the tropics and during summer seasons.High Mn/lignin ratios in fresh litter could be an indicator of lignin degradability by MnPproducing fungi across global climate gradients.
