Changes in soil bacterial communities and functional groups beneath coarse woody debris across a subalpine forest successional series
Changes in soil bacterial communities and functional groups beneath coarse woody debris across a subalpine forest successional series
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DOI：
10.1016/j.gecco.2023.e02436
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发表时间：
2023-06
影响因子：
4
通讯作者：
Zhihui Wang;M. Xu;Fei Li;Yi Bai;Jianfeng Hou;Xuqing Li;R. Cao;Yuyue Deng;Yurui Jiang;Huaibin Wang;Wanqin Yang
中科院分区：
文献类型：
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作者：
Zhihui Wang;M. Xu;Fei Li;Yi Bai;Jianfeng Hou;Xuqing Li;R. Cao;Yuyue Deng;Yurui Jiang;Huaibin Wang;Wanqin Yang
尽管粗木质碎屑(CWD)在培育生物多样性方面的作用已经有了很好的文献记载，但对于森林演替系列中不同直径的CWD如何影响土壤细菌群落的组成和多样性的了解很少。因此，本研究调查了青藏高原东部王朗国家级自然保护区6个不同演替级别和直径的森林群落下土壤细菌群落组成和生物多样性。研究中土壤细菌群落的组成和功能群随森林演替、腐烂级别和碎屑直径的不同而有很大差异。这些群落的α多样性沿演替梯度逐渐减小，但衰败级别和径级之间的差异很小。CWD下土壤细菌群落在所有土壤条件下均以变形杆菌和酸性细菌为主，其相对丰度仅随森林演替而变化较大。不同林分演替和径级间土壤细菌群落结构差异显著，但腐朽级别间差异不显著。在所有土壤条件下，官能团均以化学异养和好氧化学异养为主。在高度腐烂的类群中，固氮细菌类群和官能团丰富。土壤氮素浓度和C/N比与固氮菌群落呈负相关。土壤温度和CWD储量与CWD下土壤细菌群落的多样性和组成显著相关。综上所述，不同演替阶段不同直径和腐烂程度的CWD蕴藏着一些独特的细菌门和属，固氮细菌与高度腐烂的木材碎片的关联表明，CWD在森林生态系统中的存在可以刺激生态系统的固氮。
Although the role of coarse woody debris (CWD) in nurturing biodiversity has been well documented, there is little understanding of how CWD with varying diameters across the forest succession series affect the composition and diversity of the soil bacterial community. Therefore, this study investigated the soil bacterial community composition and biodiversity beneath debris with varying decay classes and diameters in six different successional forests, which constituted a subalpine forest series in the Wanglang National Nature Reserve in the eastern Qinghai–Tibet Plateau, China. The composition and functional groups of the soil bacterial communities in this study varied greatly with forest succession, decay classes and debris diameters. The alpha diversity of these communities decreased gradually along the succession gradients, whereas slight differences were observed among decay class and diameters. The soil bacterial communities beneath CWD were dominated by Proteobacteria and Acidobacteria under all soil conditions, and their relative abundance only varied greatly with the forest succession. The soil bacterial community structure varied significantly among different forest succession and diameters, but not decay classes. The functional groups were dominated by Chemoheterotrophy and aerobic chemoheterotrophy under all soil conditions. Nitrogen-fixing bacterial taxa and functional groups were enriched in the highly decayed classes. The soil nitrogen concentration and C:N ratio were negatively correlated with nitrogen-fixing bacterial communities. The soil temperature and CWD stock were significantly correlated with the diversity and composition of bacterial communities in soils beneath CWD. In conclusion, CWD with varying diameters and decay levels across different succession stages harbor some unique bacterial phyla and genera, and the association of nitrogen-fixing bacteria with highly decayed wood debris concluded that the existence of CWD in forest ecosystem could stimulate the ecosystem nitrogen fixation.