摘要
热带珊瑚海岛的主要成土母质为珊瑚砂,其氮素固持能力存在显著缺陷,特别是对硝态氮(NO_(3)^(-)-N)的固持效能不足,这不仅威胁岛礁淡水资源的可持续性,还影响近海生态系统的稳定性.为促进海岛-海洋生态系统的协同发展,选取生物炭(C)､铁改性生物炭(FeC)和镁改性生物炭(MgC)作为改良剂,结合本土先锋植物厚藤(P)构建协同修复体系.实验结果显示:MgC在单独应用时表现出最优的NO_(3)^(-)-N吸附性能,其吸附容量和单位表面积吸附容量(SAC)分别比FeC和C提高12.3%~28.6%.但在植物协同系统中,FeC-P组合展现出更持久的增效作用,整个实验周期维持85%以上的NO_(3)^(-)-N固持率,而MgC-P的后期固持效能出现衰减.具体而言,第40d FeC-P组的固持率达88.7%,为A-P组的1.96倍､C-P组的1.17倍和MgC-P处理组的1.10倍.机理分析表明,FeC显著提升了珊瑚砂的电导率(提升33.7%),并促进变形菌门(Patescibacteria)的增殖(相对丰度增加1.8倍),进而强化土壤基质的氮素转化功能.这种物理-化学-生物协同优化机制,使FeC与厚藤形成良性互作,从而实现珊瑚砂氮素固持能力的持续提升.
The primary parent material of tropical coral islands was coral sand,which was characterized by significant deficiencies in nitrogen retention capacity,particularly in terms of nitrate nitrogen(NO_(3)^(-)-N)immobilization efficiency.This limitation was not only jeopardizes the sustainability of freshwater resources on these islands but also compromises the stability of coastal ecosystems.To promote the synergistic development of island-marine ecosystems,this study selected biochar(C),iron-modified biochar(FeC),and magnesium-modified biochar(MgC)were selected as soil amendments.These were combined with the native pioneer plant Ipomoea pes-caprae(P)to establish a collaborative remediation system.Experimental results demonstrated that MgC exhibited optimal NO_(3)^(-)-N adsorption performance when applied individually,with its adsorption capacity and surface area-based adsorption capacity(SAC)exceeding those of FeC and C by 12.3%~28.6%.However,in plant-combined systems,a more sustained synergistic effect was demonstrated by the FeC-P combination,which maintained over 85%NO_(3)^(-)-N retention rate throughout the experimental period.In contrast,performance decline was exhibited by the MgC-P system in later stages.Specifically,an 88.7%retention rate was achieved by the FeC-P group on day 40,which was 1.96-fold of the A-P group,1.17-fold of the C-P group and 1.10-fold of the MgC-P group,respectively.Mechanistic analysis revealed that the electrical conductivity of coral sand was significantly increased by FeC(33.7%),and the proliferation of Patescibacteria was promoted(a 1.8-fold increase in relative abundance was observed),thereby strengthening the system's nitrogen transformation function.This physicochemical-biological synergistic optimization mechanism facilitated beneficial interactions between FeC and Ipomoea pes-caprae.Ultimately,a sustained enhancement of nitrogen retention capacity in coral sand was achieved.A novel technical pathway for the ecological restoration of coral islands was provided by the research outcomes.
作者
陈一平
宋世超
甘鹏飞
李芸邑
梁嘉良
赵志伟
CHEN Yi-ping;SONG Shi-chao;GAN Peng-fei;LI Yun-yi;LIANG Jia-liang;ZHAO Zhi-wei(School of Environment and Ecology,Chongqing University,Chongqing 400045;School of Civil Engineering and Transportation,Guangdong University of Technology,Guangzhou 510006,China)
出处
《中国环境科学》
北大核心
2025年第9期4997-5004,共8页
China Environmental Science
基金
“海洋环境安全保障与岛礁可持续发展”重点专项(2021-01)。
关键词
生物炭
珊瑚砂
厚藤
氮素固持
生物群落
biochar
coral sand
Ipomoea pes-caprae
nitrogen retention
microbial community
作者简介
陈一平(1998-),女,福建三明人,重庆大学博士研究生,主要研究方向为环境地球化学.发表论文4篇.yipingch@126.com;梁嘉良,副教授,liangjialiang@cqu.edu.cn;赵志伟,教授,hit_zzw@163.com。
