凋落物质量、动物群落和分解场地效应对单一和混合凋落物的分解和养分释放的比较
Title：Litter decomposition and nutrient release from monospecific and mixed litters: Comparisons of litter quality, fauna and decomposition site effects
Download websites：https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2745.13902
Abstract：Litter decomposition and nutrient release are key processes for soil C and nutrient cycling. However, the relative importance of the effects of litter quality, fauna and decomposition site on litter decomposition remains poorly understood. Moreover, the macronutrient and micronutrient (C, N, P, K, Ca, Mg, Mn, Cu and Zn) release in the decomposition process are even less well-known. In this study, we performed 5040 litterbag samplings of monospecific (Larix gmelinii, Acer mono, Quercus mongolica and Juglans mandshurica) and mixed (Larix with each broad-leaved litter) litter treatments using litterbags with three mesh sizes (for different-sized fauna) in four paired stands of natural secondary forests compared with adjacent Larix plantations in a temperate forest ecosystem in China. Litter decomposition rate and macronutrient and micronutrient release during decomposition were assessed.We found that variation in litter quality had a considerably greater effect on litter decomposition than fauna and decomposition site. The decomposition constant was significantly related to the initial litter Mg concentration and lignin/P ratio, suggesting the importance of the Mg content and lignin/P ratio in controlling litter decomposition in temperate tree species. We also showed that macrofauna significantly increased monospecific but not mixed litter decomposition. In addition, the decomposition site conditions further influenced monospecific litter decomposition. Furthermore, the litter quality significantly influences N and Mn release in both monospecific and mixed litters. Compared with Larix litter, the average of N and Mn increased 33.9% and 53.8% in three broad-leaved litters, and 21.4% and 38.0% in three mixed litters respectively. Synthesis. Litter quality is a relatively more important factor than fauna and decomposition site for the decomposition of both monospecific and mixed litters when studied at a local scale in temperate forests. Moreover, litter decomposition enhanced in plantation sites with poor soil nutrient status, which has implications for C and nutrient cycling and long-term below-ground forest ecosystem functions.
Results：
Conclusion：Litter decomposition is generally controlled by litter quality, fauna and site conditions, although the relative importance of these drivers may differ between ecosystems. In the present study, we showed that litter quality had a greater contribution to litter decomposition than fauna and decomposition site in temperate forest ecosystems. Notably, litter Mg content and lignin/P ratio explained the litter decomposition rate. The effect of fauna on litter decomposition varied with monospecific and mixed litters; macrofauna significantly enhanced monospecific litter but not mixed litter decomposition. In mixed litter decomposition, the nonadditive effects differed between the secondary forest and plantation sites, suggesting litter decomposition is determined not only by species-specific litter properties within mixtures but also by decomposition site conditions. Furthermore, differences between the decomposition rates of monospecific and mixed litters at the plantation sites emphasized that the importance of litter decomposition in restoring soil fertility in degraded plantations.
The litter initial nutrient concentration and litter types in the mixed litters influence the release and immobilization of macro- and micronutrient elements. The positive nonadditive mixture effects of nutrient release combined with monospecific and mixed litter nutrient release in plantation sites highlight the importance of improving nutrient cycling for restoring temperate forest ecosystems in soils with poor fertility.
Contact: Ran Zunian
E-mail:317804398@qq.com