Yang Jing-Yi, Wang Xu, Sun Li-Fei, Wang Chao, Bai E
Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Ying Yong Sheng Tai Xue Bao. 2020 Jun;31(6):1948-1956. doi: 10.13287/j.1001-9332.202006.007.
We carried out an experiment including nitrogen addition (N, 50 kg N·hm·a), phosphorus addition (P, 25 kg P·hm·a) and both nitrogen and phosphorus addition (NP, 50 kg N·hm·a+25 kg P·hm·a) in a natural Korean pine broad-leaved mixed forest on Changbai Mountain to examine the effects of single and combined N and P additions on soil microbial community composition and amino sugar. The results showed that N and P addition significantly reduced total microbial biomass by 19.5% and 24.6% in the organic layer of soil, while P addition significantly reduced the biomass of bacteria and fungi by 23.8% and 19.3%, respectively. In the mineral layer, N, P and NP addition significantly increased total microbial biomass by 94.8%, 230.9%, and 115.0% respectively, while the biomass of bacteria and fungi were significantly increased under all the treatments. The fungi to bacteria ratio (F/B) was significantly increased in the organic layer by N addition, while was decreased in the mineral layer soil by NP addition. The Gram-positive bacteria to Gram-negative bacteria ratio showed positive response to N, P and NP addition. Soil amino sugars responded differently to different treatments. N, P and NP addition significantly decreased glucosamine content by 41.3%, 48.8% and 36.4% in the organic layer, while N and NP addition increased muramic acid content by 43.0% and 71.1%, respectively. The contents of glucosamine and muramic acid in the mineral layer did not change significantly in response to N addition but increased significantly in response to both P addition and NP addition. The glucosamine to muramic acid ratio in the organic layer significantly decreased under fertilization treatments, indicating that N and P addition increased the relative contribution of bacteria to soil organic carbon accumulation. The changes in soil amino sugar contents were closely related to the change in microbial community composition after N and P addition, both of which were affected by changes in soil chemical properties.
我们在长白山天然红松阔叶混交林中进行了一项实验，包括添加氮（N，50 kg N·hm·a）、添加磷（P，25 kg P·hm·a）以及同时添加氮和磷（NP，50 kg N·hm·a + 25 kg P·hm·a），以研究单独添加和联合添加氮与磷对土壤微生物群落组成和氨基糖的影响。结果表明，添加氮和磷使土壤有机层中微生物总生物量分别显著降低了19.5%和24.6%，而添加磷使细菌和真菌生物量分别显著降低了23.8%和19.3%。在矿质层中，添加氮、磷和氮磷组合分别使微生物总生物量显著增加了94.8%、230.9%和115.0%，并且在所有处理下细菌和真菌的生物量均显著增加。在有机层中，添加氮使真菌与细菌的比例（F/B）显著增加，而在矿质层土壤中，添加氮磷组合使该比例降低。革兰氏阳性菌与革兰氏阴性菌的比例对添加氮、磷和氮磷组合均呈阳性响应。土壤氨基糖对不同处理的响应不同。添加氮、磷和氮磷组合使有机层中氨基葡萄糖含量分别显著降低了41.3%、48.吧%和36.4%，而添加氮和氮磷组合分别使胞壁酸含量增加了43.0%和71.1%。矿质层中氨基葡萄糖和胞壁酸的含量对添加氮无显著变化，但对添加磷和氮磷组合均显著增加。施肥处理下有机层中氨基葡萄糖与胞壁酸的比例显著降低，表明添加氮和磷增加了细菌对土壤有机碳积累的相对贡献。添加氮和磷后，土壤氨基糖含量的变化与微生物群落组成的变化密切相关，二者均受土壤化学性质变化的影响。
