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采用分解袋法,研究了川西亚高山云杉纯林与混交林叶凋落物的质量损失过程及土壤动物与微生物的作用。结果如下:(1)云杉叶凋落物分解过程中,土壤动物数量总体呈下降趋势,即土壤动物主要在分解前期发挥作用,其中,大型土壤动物早期以植食性的蛴螬为主,中期以捕食性的石蜈蚣为主,后期以腐食性的马陆为主;中小型土壤动物始终以螨类、跳虫和线虫为优势类群;相关分析表明线虫数量与云杉叶凋落物分解速率相关性最大,大型土壤动物次之。(2)云杉叶凋落物分解过程中,微生物数量总体呈上升趋势,即土壤微生物主要在分解后期发挥作用,进一步相关分析表明真菌数量与云杉叶凋落物分解速率相关性大于细菌和放线菌。(3)云杉纯林叶凋落物分解速率低于混交林,其中分解3、15、21、24个月时,纯林小孔径分解袋失重率分别为混交林的65.51%、95.73%、98.91%、94.8%,大孔径分解袋失重率分别为混交林的89.83%、92.95%、98.13%、97.13%,即,两类林分小孔径分解袋及凋落物分解前期失重率差异更为明显,表明凋落物分解速率既受底物质量的影响,也和参与分解的土壤生物有关,其中与线虫、大型土壤动物及真菌的数量相关性最大。
Using the decomposition bag method, the mass loss process of litter and the role of soil fauna and microorganisms in the pure forests and mixed forests of subalpine Spruce forests in western Sichuan were studied. The results are as follows: (1) During the litter decomposition of spruce, the number of soil fauna generally showed a decreasing trend, that is, soil fauna mainly played a role in the early decomposition. Among them, the soil fauna was dominated by phytophagous moose at early stage, Sex stone and centipede in the later stage. The predatory horseshoe crabs were dominant in the later period. Moths, hoppers and nematodes were the dominant species in small and medium-sized soil animals. The correlation analysis showed that the number of nematodes was the most related to the decomposition rate of litter, Large soil animals followed. (2) During the decomposition process of spruce leaf litter, the number of microorganisms generally showed an upward trend, that is, the soil microorganisms mainly played a role in the later decomposition stage. Further correlation analysis showed that the correlation between the number of fungi and litter decomposition rate was greater than that of bacteria and payoff bacteria. (3) The litter decomposition rate of pure spruce forest was lower than that of mixed forest. The weight loss rate of pure forest small pore size decomposition bag was 65.51%, 95.73%, 98.91 % And 94.8%, respectively. The weight loss rate of the macropore decomposition bag was 89.83%, 92.95%, 98.13% and 97.13% of the mixed forest respectively. That is to say, the difference of weight loss between the two types of small pore size decomposition bags and litter decomposition was more obvious, The results showed that the decomposition rate of litter was affected by the substrate quality and also with the soil organisms involved in the decomposition, with the largest correlation with the numbers of nematodes, soil macrofauna and fungi.