草原羊草（Leymuschinensis）和大针茅（Stipagrandis）不同物候期植株残体及凋落物分解酶活性的研究

本文就不同物候期的羊草和大针茅植株残体和凋落物分解过程中的分解酶活性的一些特点进行了研究，结果是：植株残体分解初期，蛋白酶和转化酶活性强度表现为返青期＞结实期＞果后营养期；羊草植株残体的蛋白酶、转化酶和纤维素酶活性均高于大针茅；从设置条件来看，各酶活性强度均为埋置＞地表。但随植株残体的进一步被分解，上述结果呈现相反的变化趋势；纤维素酶活性除分解头一年（１９８８年）返青期略高于结实期外，此后各年均为果后营养期＞结实期＞返青期；凋落物分解过程中，分解酶活性有明显的季节性变化和年度间的优势交替现象，即酶活性在一年中，夏季最高，春秋次之，冬季最低；在各年度间，转化酶最先出现优势峰朗，蛋白酶随后出现，纤维素酶的峰期继之其后，可见牧草各物候期植株残体和调落物分解过程中的分解酶活性强度与牧草植株体和凋落物所能提供的酶促底物量，植株及其凋落物被分解的难易程度和所处环境条件紧密关联，同时亦反映其分解过程中各自的酶促特性．

A Study of Decomposition Enzyme Activities of Plant Residues and Litter of Different Phenoliogical Periods of Leyimus chinensis and Stipa grandis

his paper is a study of some characters of enzyme activities in the decomposition cotirse ofplant litter and residues of different phenological period of Leymus chinensis andStifa grandis.The result is as follows:1)In the early period of decompostion of plantresidue,the activity inten-sity of protease and invertase shows the following pattern :green up period>seed period>nutrientafter seed period , the activity of protease , invertase reducing and cellulase in Leymus chinensis ishigher than that in Stipa grandis, looking from the placing condition,every enzyme activity is:un-der-ground>above-ground. But with further decomposition of plant residues,the above result in-dicates changes in conrary direction. 2)The enzyme activity of cellulase in the first year of decom-position green tip period>seed period , whereas in the later years; it is nutrient after seed > seedperiod>green up period.3. In the decomposition course of plant residues , the decomposition en-zyme activity shows obvious seasonal changes and annual alternation of dominance,thar is to say,the enzyme activity is the highest in summer,then comes that in spring,with the lowest in winter.Annually , invertase reaches the peak period first , then followed by protease and cellulase in thissequence. Therefore the conclusion: the intensity of clecomposition enzyme actvity of the plantresidues and litters of different phenoliogical periods in the course of decomposition is closely re-lated to substrt number of enzymic reaction provided by plant residues and litters ,and to the de-grees of decomposition of plants and their litters and surroundings , and shows the individual en-zymic rection characteristics in the course of decomposition.