模拟氮沉降对中亚热带米槠天然林土壤解磷微生物群落和功能潜力的影响  

Effects of simulated nitrogen deposition on soil microbial community and functional potential of phosphate⁃solubilizing microorganisms in a subtropical Castanopsis carlesii forest

作　　者：夏允 徐玲琳[1,2,3] 杨柳明 杨智杰[1,2,3] 范跃新[1,2,3] 杨玉盛[1,2,3] XIA Yun;XU Linglin;YANG Liuming;YANG Zhijie;FAN Yuexin;YANG Yusheng(School of Geographical Science,Fujian Normal University,Fuzhou 350007,China;Fujian Provincial Key Laboratory for Plant Ecophysiology,Fujian Normal University,Fuzhou 350007,China;Institute of Geography,Fujian Normal University,Fuzhou 350007,China)

机构地区：[1]福建师范大学地理科学学院,福州350007 [2]福建师范大学福建省植物生理生态重点实验室,福州350007 [3]福建师范大学地理研究所,福州350007

出　　处：《生态学报》2024年第4期1727-1736,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金(41977090,32192433,32171587)。

摘　　要：解磷微生物是森林土壤磷循环的关键驱动因素,对亚热带低磷土壤尤为重要。由于微生物对环境变化较为敏感,氮沉降下土壤微生物如何变化以及如何影响土壤磷有效性尚不清楚。为此,依托福建三明森林生态系统与全球变化国家野外科学观测研究站建立的米槠天然林长期氮沉降观测平台,借助16S rRNA和ITS高通量测序以及PICRUSt功能预测方法,探索氮添加对土壤解磷微生物群落和功能潜力的影响。结果表明:氮添加显著增加了土壤有效氮含量,但显著降低了Resin-P、NaHCO_(3)-P和TPo,表明氮沉降改变了土壤养分平衡,加剧了磷限制。此外,氮添加降低了根瘤菌和伯克霍尔德菌等解磷细菌的丰度,却增加了青霉菌和曲霉菌等解磷真菌的丰度。PICRUSt功能预测进一步发现,存在15种能够编码磷酸酶的基因,并且与对照相比,施氮后酸性磷酸酶、碱性磷酸酶和植酸酶等酶基因丰度显著增加。综上,本研究发现施氮加剧了亚热带米槠天然林土壤的磷限制,同时增加了解磷真菌的丰度和磷酸酶的基因丰度来促进有机磷矿化,这可能是氮沉降下驱动米槠天然林土壤磷转化的主要微生物机制。Phosphate-solubilizing microorganisms are the key factors in driving phosphorus(P)cycle in forest soil,especially in subtropical forest soil where P is scarce.Although microorganisms are sensitive to environmental changes,it is still unclear the changes in microbial function and their effects on soil P cycling in response to nitrogen(N)deposition.In this study,a long-term N deposition experiment platform was established in the Castanopsis Carlesii natural forest at the National Research Station of Forest Ecosystem and Global Change in Sanming,Fujian Province.Through the 16S rRNA and ITS-based high-throughput sequencing and PICRUSt functional prediction methods,we investigated the effects of N addition on the community and functional potential of phosphate-solubilizing microorganisms in the soil.The results showed that the N addition significantly increased the available N content of the soil,but significantly decreased Resin-P,NaHCO_(3)-P,and TPo,indicating that N deposition altered the soil nutrient balance and aggravated soil P limitation.In addition,N addition significantly decreased the abundance of phosphate-solubilizing bacteria such as Rhizobia and Burkholder,while increased the abundance of phosphate-solubilizing fungi such as Penicillium and Aspergillus.The prediction analysis of the function of phosphate-solubilizing microorganisms by PICRUSt also further revealed 15 genes that are capable of encoding phosphatases,the abundance of genes encoding enzymes such as acid phosphatase,alkaline phosphatase,and phytase increased significantly after N addition.In conclusion,N addition induced P limitation in this subtropical Castanopsis carlesii forest.The increased phosphate-solubilizing fungi and the associated increases in phosphatase genes might be beneficial to organic phosphate mineralization,which may act as the main microbial mechanism driving soil P transformation in Castanopsis carlesii natural forest under N deposition.

关 键 词：解磷微生物 磷酸酶 高通量测序 PICRUSt功能预测 

分 类 号：S714.3[农业科学—林学]