Variation in litter decomposition-temperature relationships between coniferous and broadleaf forests in Huangshan Mountain, China

Abstract

A study was conducted to identify the differences in the decompositions of leaf litter, lignin and carbohydrate between coniferous forest and broadleaf forest at 20°C and 30°C in Huangshan Mountain, Anhui Province, China. Results showed that at 20°C mass loss of leaf litter driven by microbial decomposers was higher in broadleaf forest than that in coniferous forest, whereas the difference in mass loss of leaf litter was not significant at 30°C. The temperature increase did not affect the mass loss of leaf litter for coniferous forest treatment, but significantly reduced the decomposition rate for broadleaf forest treatment. The functional decomposers of microorganism in broadleaf forest produced a higher lignin decomposition rate at 20°C, compared to that in coniferous forest, but the difference in lignin decomposition was not found between two forest types at 30°C. Improved temperature increased the lignin decomposition for both broadleaf and coniferous forest. Additionally, the functional group of microorganism from broadleaf forest showed marginally higher carbohydrate loss than that from coniferous forest at both temperatures. Temperature increase reduced the carbohydrate decomposition for broadleaf forest, while only a little reduce was found for coniferous forest. Remarkable differences occurred in responses between most enzymes (Phenoloxidase, peroxidase, β-glucosidase and endocellulase) and decomposition rate of leaf litter to forest type and temperature, although there exist strong relationships between measured enzyme activities and decomposition rate in most cases. The reason is that more than one enzyme contribute to the mass loss of leaf litter and organic chemical components. In conclusion, at a community scale the coniferous and broadleaf forests differed in their temperature-decomposition relationships.