短期氮沉降对速生期杉木人工林细根性状的影响及其驱动因素  

Effects of Short-term Nitrogen Deposition on Fine Root Traits of Fast-growing Chinese Fir Plantation and Its Driving Factors

作　　者：张锦秀 曹聪 陆宇明 姜永孟 王曼 曾志伟 郑琳敏 林伟盛[1,2] 吕茂奎[1,2,3] 谢锦升 ZHANG Jinxiu;CAO Cong;LU Yuming;JIANG Yongmeng;WANG Man;ZENG Zhiwei;ZHENG Linmin;LIN Weisheng;LV Maokui;XIE Jinsheng(School of Geographical Sciences,School of Carbon Neutrality Future Technology,Fujian Normal University,Fuzhou 350117,China;Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education,Fujian Normal University,Fuzhou 350117,China;Forest Ecosystem National Observation and Research Station,Sanming 365002,Fujian,China)

机构地区：[1]福建师范大学地理科学学院,碳中和未来技术学院,福州350117 [2]福建师范大学湿润亚热带生态地理过程教育部重点实验室,福州350117 [3]福建三明森林生态系统国家野外科学观测研究站,福建三明365002

出　　处：《亚热带资源与环境学报》2025年第1期136-144,共9页Journal of Subtropical Resources and Environment

基　　金：国家自然科学基金面上项目(32371659);国家自然科学基金青年项目(32001169);福建省基金面上项目(2021J01179)。

摘　　要：氮沉降增加对地下生态系统过程具有重要影响,会造成根系形态和功能性状的变化,从而深刻影响生态系统碳、氮循环。目前对氮沉降如何影响亚热带杉木人工林细根动态的研究还比较有限。本研究通过设置氮添加(40 kg·hm^(-2)·a^(-1))实验模拟氮沉降,探讨氮添加对杉木人工林土壤理化性质和细根性状的影响。以杉木人工林为研究对象,采用随机区组设计,在氮添加的半年和1年后采集0~10 cm和10~20 cm的土壤和细根,并综合分析了土壤基本理化指标、一级根和二级根的根系功能性状的变化趋势。结果表明:施氮半年后土壤中可溶性有机氮(DON)、NH 4+含量增加,施氮1年后减少,DON含量变化在0~10 cm土层中更显著,施氮1年后两土层可溶性有机碳(DOC)均显著下降。氮添加对杉木一级根和二级根的直径和组织密度没有显著影响,但在氮添加1年后显著增加10~20 cm土层杉木一二级根的比根长和比表面积。杉木一级根和二级根的细根生物量和总生物量没有显著变化,但0~10 cm土层的林下植被根系生物量显著降低了100%。氮沉降背景下,杉木人工林土壤中的矿质氮和可溶性有机质(DOM)首先受到影响,杉木会通过改变细根性状和降低林下植被生物量的方式提升自身根系的养分获取能力应对环境变化。Increased nitrogen deposition has important effects on below-ground ecological processes.It will cause changes of root morphological and functional traits,thus deeply affecting ecosystem carbon(C)and Nitrogen(N)cycles.This study simulated nitrogen deposition by setting up a nitrogen addition(40 kg·hm^(-2)·a^(-1))experiment to explore the effects of nitrogen addition on soil physical and chemical indexes and fine root traits of Chinese fir plantation.Chinese fir plantations were used as the study object and a randomized block design was adopted.Soil and fine roots at 0~10 cm and 10~20 cm depths were collected half a year and one year after nitrogen addition,and the basic physical and chemical properties of the soil,as well as changing trends of root functional traits of primary roots and secondary roots were comprehensively analyzed.The results show that the content of dissolved organic nitrogen(DON)and NH 4+in the soil increased after half a year of nitrogen addition,and decreased after one year of nitrogen addition.The change in DON content was more significant in the 0~10 cm soil layer.The dissolved organic carbon(DOC)in both soil layers decreased significantly after one year of nitrogen addition.Nitrogen addition had no significant effect on the diameter and tissue density of primary and secondary roots of fir,but it significantly increased the specific root length and specific surface area of primary and secondary roots of fir in the 10~20 cm soil layer after one year of nitrogen addition.There was no significant change in fir fine root biomass and total root biomass in primary and secondary roots,but the root biomass of 0~10 cm understory vegetation significantly reduced by 100%.Under the background of nitrogen deposition,the mineral nitrogen and dissolved organic matter in the soil of the Chinese fir plantation were affected first.The Chinese fir will increase the nutrient acquisition capacity of its own roots in response to environmental changes by changing the characteristics of fine roots and reducing

关 键 词：氮添加 根序 细根 形态性状 

分 类 号：S714.3[农业科学—林学]