Xu Jie, Liu Bing, Qu Zhao-Lei, Ma Yang, Sun Hui
Collaborative Innovation Center of Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China.
Microorganisms. 2020 May 28;8(6):811. doi: 10.3390/microorganisms8060811.
Soil microorganisms and extracellular enzymes play important roles in soil nutrient cycling. Currently, China has the second-largest area of eucalyptus plantations in the world. Information on the effects of eucalyptus age and species of trees on soil microbial biomass and enzyme activities, however, is limited. In this paper, the soil microbial biomass and enzyme activities were studied in eucalyptus plantations with different ages (1 and 5 years) and species of trees (. , and ) in South China. The results showed that both plantation age and eucalyptus species could affect the total microbial biomass and fungal biomass, whereas the bacterial biomass was affected only by plantation age. The fungal biomass and the fungi-to-bacteria ratio significantly increased along with increasing plantation age. Similarly, the plantation age and eucalyptus species significantly affected the enzyme activities associated with carbon cycling (β-xylosidase, β-d-glucuronidase, β-cellobiosidase and β-glucosidase). The activities of β-d-glucuronidase and β-glucosidase were significantly higher in the plantation. The enzymes involved in nitrogen (N-acetyl-glucosamidase) and sulfur (sulfatase) cycling were only affected by the eucalyptus plantation age and species, respectively. The results highlight the importance of the age and species of eucalyptus plantations on soil microbial activities.
土壤微生物和胞外酶在土壤养分循环中发挥着重要作用。目前，中国拥有世界上第二大的桉树人工林面积。然而，关于桉树树龄和树种对土壤微生物生物量及酶活性影响的信息却很有限。本文对中国南方不同树龄（1年和5年）及不同树种（. 、 和 ）的桉树林土壤微生物生物量及酶活性进行了研究。结果表明，人工林树龄和桉树树种均能影响微生物总量和真菌生物量，而细菌生物量仅受人工林树龄影响。真菌生物量和真菌与细菌的比例随人工林树龄的增加而显著增加。同样，人工林树龄和桉树树种对与碳循环相关的酶活性（β - 木糖苷酶、β - D - 葡萄糖醛酸酶、β - 纤维二糖酶和β - 葡萄糖苷酶）有显著影响。在 人工林中，β - D - 葡萄糖醛酸酶和β - 葡萄糖苷酶的活性显著更高。参与氮（N - 乙酰 - 葡萄糖胺酶）和硫（硫酸酯酶）循环的酶分别仅受桉树林树龄和树种的影响。研究结果突出了桉树林树龄和树种对土壤微生物活性的重要性。
