森林枯枝落叶分解过程的微生物学特性

STUDIES ON THE MICROBIOLOGICAL PROPERTIES DURING THE DECOMPOSITION PROCESS OF THE FOREST LITTERS

森林枯枝落叶是补亢森林土壤有机质的主要来源。枯枝落叶的分解过程,对于恢复和增进土壤肥力、改善林木营养和提高森林生产力,有着极为密切的关系。 在文献中,对森林枯枝落叶分解过程的研究有过不少的报道。其中不仅有关于枯枝落叶的特性、土壤有机质的积累、矿化过程中元素循环等研究资料(等,1954,1959;等,1961;Fcnton,1958)

The present paper dealt with the results of the preliminary investigation on the microbiological properties during the decomposition process of forest litters carried out under the laboratory conditions. The authors attempted to apprehend the correlation between the decomposition process of forest litters accumulated under the different forest types and the dynamic of the soil microorganisms and the activities of the soil enzymes.Experimental results revealed that the numbers of the microorganisms, the intensity of the biochemical process and the activities of the enzymes in the treatments with the addition of forest litters were much higher than those of the soil alone. The addition of the litters from Tilieto-Pinetum gave higher effects than the addition of the litters from Querceto-Pinetum. It reflected that the litters of Tilieto-Pinetum which contained broad-leaves would decompose more vigorously than the litters of Querceto-Pinetum which contained solely pine-needles. The variation in the rates of decomposition of the carbonaceous and nitrogenous materials in soil demonstrated that the biochemical process undergoing in the soils with additions of various litters were different. In the treatment with additionof the litters from Tilieto-Pinetum, the total carbon and reducing sugars decreased much more than that in the treatment with addition of the litters from Querceto-Pinetum during the decomposition process. This proved the fact that in the former treatment the rate of decomposition of the litters was more quickly than the latter. But there was no distinct difference in their liberation of the carbon dioxide.During the decomposition of litters through a period of 120 days, the variation of the activities of soil enzymes at different period were not distinct in both treatments with the forest litters. In the primary stage of decomposition of the litters, the activities of the hydrolytic enzymes (invertase, urease and proteinase) were more intensive. But in the later stage, the activities of the oxidative enzymes (polyphenol oxidase and catalase) increased. These variations in enzyme activities showed that in the early stage the process of decomposition proceeded mainly, while in the later stage, in accompany with the decomposition process, the resyn-thesisprocess proceeded intensively.The experimental results revealed that the abundance and the composition of soil microorganisms in the different treatments varied during the decomposition of the forest litters. The variation in the abundance of microorganisms in different period were essentially similar, but a definite variation in the proportion of the different groups of the microorganisms existed. The variation in the abundance of microorganisms demonstrated that the soluble and easily decomposible materials were decomposed in the primary stage of decomposition process of litters. In the later stage of decomposition process, the hardly decomposible materials were undergoing decomposition.