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采用凋落物分解袋法,以宁南山区典型草本植物长芒草、铁杆蒿、百里香为研究对象,分析了3种植物茎叶分解过程中土壤酶活性变化特征和分解后期微生物多样性特征,以及土壤酶活性与初始土壤化学性质的关系.结果表明:植物茎叶分解480 d后,各处理土壤酶活性均有不同程度的增加,且长芒草处理土壤蔗糖酶活性和碱性磷酸酶活性最高,分别为32.40和1.99 mg·g~(-1)·24 h~(-1),百里香处理土壤脲酶活性最高(2.66 mg·g~(-1)·24 h~(-1)),铁杆蒿处理土壤纤维素酶活性最高(1.42 mg·g~(-1)·72 h~(-1)).分解末期土壤纤维素酶活性与土壤初始微生物生物量碳呈显著正相关;分解末期土壤纤维素酶活性与土壤初始硝态氮含量呈显著负相关.添加植物茎叶处理土壤细菌和真菌的Ace指数、Chao指数和Shannon指数均显著大于对照,Simpson指数显著小于对照.植物茎叶的分解显著提高了土壤细菌和真菌的丰度及多样性,进而提高了植物茎叶的分解速率,促进了生态系统营养物质的循环与转化.
Using the litter decomposition bag method, the typical herbaceous plants such as Magnolia cristata, Artemisia fortunei and thyme in the south of Ningxia were studied. The characteristics of soil enzyme activities and microbial diversity during the decomposition of stem and leaf of the three plants were analyzed. The results showed that after 48 days of decomposition of plant stems and leaves, the soil enzyme activities of all treatments increased to some extent, and the activities of invertase and alkaline phosphatase of the soil were the highest Was 32.40 and 1.99 mg · g -1 · 24 h -1, and the highest urease activity was 2.66 mg · g -1 · 24 h -1 in the treatment of Thyme, Soil cellulase activity was the highest (1.42 mg · g -1 · 72 h -1). At the end of decomposition, there was a significant positive correlation between soil cellulase activity and soil microbial biomass carbon There was a significant negative correlation between enzyme activity and soil nitrate content. The Ace index, Chao index and Shannon index of soil bacteria and fungi were significantly higher than those of the control, while the Simpson index was significantly lower than that of the control Soil bacteria and fungi And diversity, thereby increasing the rate of decomposition of plant stems and leaves, and promote the circulation of nutrients and transformation of ecological systems.