氮肥添加对高寒藏嵩草(Kobresia tibetica)沼泽化草甸和土壤微生物群落的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 氮肥添加对高寒藏嵩草(Kobresia tibetica)沼泽化草甸和土壤微生物群落的影响 DOI: 10.5846/stxb201508041642 作者: 作者单位: 西南民族大学生命科学与技术学院;中国科学院水利部成都山地灾害与环境研究所;中国科学院成都生物所,中国科学院水利部成都山地灾害与环境研究所,中国科学院成都生物所,西南民族大学生命科学与技术学院,西南民族大学生命科学与技术学院,西南民族大学生命科学与技术学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点基础研究发展计划（973计划）（2013CBA01807）；国家自然科学基金项目（31370542）；中央高校基本科研业务费优秀科研团队及重大孵化项目（2014NZYTDO1） Effects of N addition on the plant and soil microbial community in alpine Kobresia tibetica meadow of Qinghai-Tibet Plateau Author: Affiliation: College of Life Science and Technology,Southwest University for Nationalities,,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以藏嵩草沼泽化草甸为研究对象，利用磷脂脂肪酸（PLFA）技术，研究连续6年N素添加对地上植被群落数量特征、土壤微生物群落结构的影响。结果表明：①藏嵩草沼泽化草甸群落生物量、枯枝落叶对施肥处理无明显响应，且莎草科植物对土壤氮素的吸收和利用率较低。②施肥增加了0-10 cm土壤微生物类群PLFAs丰富度，尤其细菌和革兰氏阳性菌PLFAs，降低了10-20 cm PLFAs丰富度；③磷脂脂肪酸饱和脂肪酸/单烯不饱和脂肪酸、细菌PLFAs/真菌PLFAs的比值随土壤层次增加而增加；④ 0-10 cm土层，革兰氏阳性菌、真菌PLFAs含量与pH、土壤速效磷、速效氮、土壤有机质显著正相关（P < 0.05或P < 0.01）；10-20 cm土层，细菌、革兰氏阳性菌、真菌和总PLFAs含量与土壤有机质含量显著正相关（P < 0.05或P < 0.01）。表明藏嵩草沼泽化草甸微生物PLFAs含量和丰富度对施肥的响应存在明显的土层梯度效应，土壤微生物PLFAs含量和丰富度主要受表层土壤初始养分含量的影响。 Abstract:Effects of continuous six-year N addition on the quantitative properties of plant and soil microbial communities in alpine Kobresia tibetica meadows were investigated experimentally by using field surveys and phospholipid fatty acid (PLFA) analyses. The experiment included four manipulative treatments involving both N and litter:added N (+N) with the litter removed (LR), +N with the litter left intact (LI), LI without N addition (-N), and LR with -N. Soil samples were collected at the depths of 0-10 and 10-20 cm. Aboveground biomass (AGB), litter biomass, microbial community composition, and nutrient content were measured. The results showed that (1) fertilization did not have significant effects on AGB and litter biomass. (2) N addition significantly increased the abundance of the microbial group PLFAs at the soil depth of 0-10 cm, particularly the abundance of the bacterial PLFAs (B PLFAs) and gram-positive bacterial PLFAs (G+ PLFAs), but decreased microbial abundances at the soil depth of 10-20 cm. (3) The ratio of the normal saturated fatty acids/monounsaturated fatty acids and B PLFAs/fungal PLFAs (F PLFAs) increased with the increase in the soil depth. (4) G+ PLFA and F PLFA contents were significantly and positively correlated to pH, available phosphorus, available nitrogen, and soil organic matter contents at 0-10 cm soil depth. The contents and abundance of fatty acids were mainly regulated and affected by initial nutrient level in the topsoil after short-term N addition. These results indicate that microbial communities in this alpine tundra are sensitive to both litter and N inputs, and that the vertical structures of these communities are particularly vulnerable. 参考文献 相似文献 引证文献