Linkages of C:N:P stoichiometry and bacterial community in soil following afforestation of former farmland
Linkages of C:N:P stoichiometry and bacterial community in soil following afforestation of former farmland
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DOI：
10.1016/j.foreco.2016.06.004
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发表时间：
2016-09
影响因子：
3.7
通讯作者：
C. Ren;F. Zhao;Di Kang;Gaihe Yang;Xinhui Han;X. Tong;Yongzhong Feng;Guangxin Ren
中科院分区：
文献类型：
--
作者：
C. Ren;F. Zhao;Di Kang;Gaihe Yang;Xinhui Han;X. Tong;Yongzhong Feng;Guangxin Ren
土壤中的生态化学计量学(C：N：P比)在生态系统的动态和功能中起着重要的作用，但其与植树造林后地下微生物多样性的关系却知之甚少。为了阐明土壤中C、N、P与微生物生物量的关系，以及对土壤细菌群落的影响，从农田和过去40年来一直耕种的三个绿地--刺槐、锦鸡儿和荒地--采集了土壤样品。利用16S rRNA基因的定量PCR和Illumina测序分析了土壤细菌的丰度、多样性和组成。此外，还估计了土壤性质和土壤中的C、N、P水平以及微生物生物量。结果表明，造林后土壤中的C、N、P含量与微生物生物量均有不同程度的增加，且相关关系显著，尤其是N/P比值。此外，造林后土壤细菌数量和多样性增加，并与土壤C：P和N：P比例有关。相对丰度较高(相对丰度为1%)的土壤细菌门在造林后的组成响应中表现出不一致的方向性趋势。植树造林后，变形杆菌、酸性细菌和硝化细菌的丰度增加，而绿藻的丰度则相反(P<0.05)。这在很大程度上受到土壤中N/P比和微生物生物量变化的影响。综上所述，土壤中氮磷比的显著增加反映了土壤中磷的缺乏，这将限制微生物生物量和多样性的增加。因此，在植树造林过程中，磷状况应成为森林可持续恢复的重要因素。
Ecological stoichiometry (C:N:P ratios) in soil plays an important role in ecosystem dynamics and functioning; however, its relationship with below-ground microbial diversity following afforestation remains poorly understood. To illustrate the linkage of C, N, and P in soil and microbial biomass, and the effect on the soil bacterial community, soil samples were collected from farmland and from three afforested land, namelyRobinia pseudoacaciaL.,Caragana korshinskiiKom, and abandoned land, which have been arable for the past 40 years. Quantitative PCR and Illumina sequencing of the 16S rRNA genes were used to analyze soil bacterial abundance, diversity, and composition. Additionally, soil properties and C, N, and P levels in soil and microbial biomass were estimated. The results revealed that C, N, and P levels in soil and microbial biomass increased following afforestation, with a significant correlation observed, especially for the N:P ratio. Additionally, a rise in - and -diversity of soil bacteria was observed in response to afforestation, and was linked to soil C:P and N:P ratios. Soil bacterial phyla with high relative abundance (relative abundance > 1%) across all samples showed inconsistent directional trends in the composition response after afforestation. An increased abundance of Proteobacteria, Acidobacteria, and Nitrospirae were observed, while the abundance of Chloroflexi was opposite (P < 0.05) following afforestation. Those were largely influenced by changes in the N:P ratio in soil and microbial biomass. Taken together, significantly increased N:P ratio in soil reflected the deficient P that would be limited for increased microbial biomass and diversity. Thus, P status should be an important factor for sustainable restoration of the forest during the process of afforestation.