1 山西农业大学 a. 林学院
2 山西农业大学 b. 农学院, 太谷 030801
土壤细菌群落在草地生态系统土壤碳、氮养分代谢和循环过程中发挥着关键作用。本研究以关帝山林区3种典型退化草地群落类型为研究对象, 选用高通量测序技术测定其土壤细菌群落组成及生物多样性, 采用QIIME软件、R语言和ANOVA方差分析对数据进行统计和分析。结果表明: 不同退化程度草地群落类型土层间土壤细菌群落组成及α多样性差异性显著; 重度退化的苔草草地(CS)表层土壤细菌α多样性最高, 利用和降解土壤有机质能力的芽单胞菌门(Gemmatimonadetes)和节杆菌属(Arthrobacter)的丰度值也最高; 草地土壤中反硝化细菌是重要的优势菌群, 其丰度含量随草地退化程度增加而显著增高; 土壤细菌群落可通过降解土壤有机质和土壤反硝化作用, 导致草地土壤有机质含量降低和土壤氮素流失, 进而加速草地的退化。本研究结论为阐明关帝山林区草地退化主要成因和开展相关生态恢复与保护工作提供了重要的科学依据。
关帝山林区 退化草地 细菌群落组成 生物多样性 优势菌群 Guandi Mountain forest region degraded grassland bacterial community composition biodiversity dominant flora
Author Affiliations
Abstract
1 Wuhan National Lab for Optoelectrics, Huazhong University of Science and Technology, Wuhan 430074, China
2 Accelink Technologies Co., Ltd., Wuhan 430205, China
A bandwidth-tunable optical passband filter with tunable attenuation is proposed. The filter, composed of a transmission liquid crystal array and high-resolution diffraction grating, was successfully demonstrated based on the compact spatial light design. Experimental results showed that the bandwidth, wavelength, and attenuation could be tuned by controlling the voltage applied on the liquid crystal array. The insertion loss was less than 3 dB; the attenuation tuning range was from 0 to 15 dB. The bandwidth tuning range was from 50 to 5000 GHz, which covered the full C band. The filter can meet the technical requirements of colorless-directionless-contentionless-flexible reconfigurable optical add/drop multiplexer.
060.2605 Free-space optical communication 130.7408 Wavelength filtering devices Chinese Optics Letters
2018, 16(7): 070602
