Organic mulching provides C and N source to the soil, changing the soil environment and promoting plant growth. Soil enzymes play important roles in soil organic matter decomposition and nutrient cycling. However, changes in enzyme activity after organic mulching in urban forest ecosystems remain poorly understood, especially in rhizosphere soil. In this study, the effects of organic mulching on the activity levels of enzymes relevant to C and N in the rhizosphere and bulk soil were investigated in a 15-year-old Ligustrum lucidum urban forest. Invertase activity increased whereas urease activity decreased after organic mulching. Changes in peroxidase and dehydrogenase activity varied across seasons; these changes were greater and lasted longer than changes in invertase and urease activity because of the stronger organic matter decomposition via microbial action and soil substance cycling and transformation in a short period of time after organic mulching. Enzyme activity in the rhizosphere significantly correlated with that in bulk soil (P < 0.01), though the former was more affected by mulching due to the influence of accelerated root element cycling. Enzyme activity levels were significantly correlated with dissolved C, available N, and microbial biomass C and N, but not with soil organic C or total N. Enzyme activities were also affected by physical factors, such as soil temperature and water content. Frequent applications of small quantities of organic mulch may be conducive to soil improvement. Further long-term comprehensive studies, considering the effects of season and soil layer, are required to elucidate the effects and underlying mechanisms of organic mulching on the soil environment in forest ecosystems.

有机覆盖为土壤提供了碳和氮源，改变了土壤环境并促进了植物的生长。土壤酶在土壤有机质分解和养分循环中起着重要作用。但是，对城市森林生态系统中有机覆盖后酶活性的变化知之甚少，尤其是在根际土壤中。在这项研究中，以15岁女贞为研究对象，研究了有机覆盖对根际和土壤中与C和N相关的酶活性水平的影响。城市森林。有机覆盖后，转化酶活性增加，而脲酶活性降低。过氧化物酶和脱氢酶活性的变化随季节而变；这些变化比蔗糖酶和脲酶活性的变化更大，持续时间更长，这是由于有机覆盖后短时间内微生物通过微生物作用以及土壤物质循环和转化而产生的更强的有机物分解作用。根际中的酶活性与散装土壤中的酶活性显着相关（P <0.01），但由于根元素循环加速的影响，前者受覆盖的影响更大。酶的活性水平与溶解的碳，有效氮以及微生物生物量碳和氮显着相关，但与土壤有机碳或总氮无关。酶的活性还受到诸如土壤温度和含水量等物理因素的影响。频繁施用少量有机覆盖物可能有利于土壤改良。需要进一步的长期综合研究，考虑季节和土壤层的影响，以阐明有机覆盖对森林生态系统土壤环境的影响及其潜在机制。