Cao Chengyou, Zhang Ying, Cui Zhenbo, Feng Shuwei, Wang Tingting, Ren Qing
College of Life and Health Sciences, Northeastern University, Shenyang, 110169, People's Republic of China.
Appl Microbiol Biotechnol. 2017 Aug;101(15):6217-6228. doi: 10.1007/s00253-017-8336-z. Epub 2017 May 31.
Grasslands in semi-arid Northern China are widely desertified, thus inducing the formation of a large area of moving sand lands. Revegetation of the sandy land is commonly adopted to restore degraded grasslands. The structure of the soil microbial community might dramatically change during degradation and recovery because microorganisms are one of the major drivers of ecological process through their interactions with plants and soil. Assuming that soil properties are the key determinants of the structure of soil bacterial community within the same soil type, whether the vegetation type causes the significant difference in the structure of soil bacterial community during revegetation and restoration of the degraded grasslands remains poorly understood. Our study aimed to (1) investigate the response of soil bacterial communities to the changes during vegetation degradation and recovery and (2) evaluate whether the soil bacterial communities under plantations return to their native state. We detected the shifts in diversities and compositions of the soil bacterial communities and the relative abundance of dominant bacterial taxa by using the high-throughput Illumina MiSeq sequencing technique in an area covered by 32-year-old Caragana microphylla, Artemisia halodendron, Hedysarum fruticosum, Pinus sylvestris var. mongolica, Populus simonii, and Salix gordejevii sand-fixing plantations and in the native community (NC) dominated by elm, and moving sandy dune (MS). We found that the obtained operational taxonomic units by 16S rRNA gene sequencing and diversity index in MS were all significantly lower than those in NC, and the number and composition of dominant genera were significantly different between NC and MS. Interestingly, the compositions of bacterial communities and the dominant genera in different sand-fixation plantations (C. microphylla, A. halodendron, H. fruticosum, P. sylvestris var. mongolica, P. simonii, and S. gordejevii) were all similar to those of the native soil of NC, suggesting that the plantation type and soil properties exhibit a minimal effect on the compositions of soil microbial communities within a continuous landscape. These results revealed that the structure of the soil bacterial community of degraded sandy grassland (even degenerated into a mobile sand dunes) in semi-arid region can be reversibly restored by planting indigenous shrub or semi-shrub plantation on human time scales.
中国北方半干旱地区的草原广泛沙化，从而导致大面积流动沙地的形成。沙地植被恢复是恢复退化草原常用的方法。由于微生物通过与植物和土壤的相互作用，是生态过程的主要驱动因素之一，因此在退化和恢复过程中，土壤微生物群落结构可能会发生显著变化。假设土壤性质是同一土壤类型中土壤细菌群落结构的关键决定因素，那么在退化草原植被恢复和重建过程中，植被类型是否会导致土壤细菌群落结构产生显著差异，目前仍知之甚少。我们的研究旨在：（1）调查土壤细菌群落对植被退化和恢复过程中变化的响应；（2）评估人工林土壤细菌群落是否恢复到其原始状态。我们在一片覆盖着树龄32年的小叶锦鸡儿、差巴嘎蒿、花棒、樟子松、小叶杨和黄柳固沙人工林以及以榆树为主的原生群落（NC）和流动沙丘（MS）的区域，使用高通量Illumina MiSeq测序技术，检测了土壤细菌群落多样性和组成的变化以及优势细菌类群的相对丰度。我们发现，通过16S rRNA基因测序获得的MS中的操作分类单元和多样性指数均显著低于NC中的，且NC和MS之间优势属的数量和组成存在显著差异。有趣的是，不同固沙人工林（小叶锦鸡儿、差巴嘎蒿、花棒、樟子松、小叶杨和黄柳）中的细菌群落组成和优势属均与NC的原生土壤相似，这表明在连续景观中，人工林类型和土壤性质对土壤微生物群落组成的影响最小。这些结果表明，在半干旱地区，退化沙地草原（甚至退化为流动沙丘）的土壤细菌群落结构在人类时间尺度上可以通过种植本土灌木或半灌木人工林得到可逆恢复。
