模拟氮沉降对中亚热带桉树人工林土壤有机碳组分及碳库管理指数的影响  

Effects of Simulated Nitrogen Deposition on Soil Organic Carbon Fractions and Carbon Pool Management Indicators in Mid-subtropical Eucalyptus Plantations

作　　者：毛馨月 沈育伊[3] 褚俊智 徐广平[2] 王紫卉 曹杨 陈运霜 张德楠[2] 孙英杰[2] 黄科朝 MAO Xin-yue;SHEN Yu-yi;CHU Jun-zhi;XU Guang-ping;WANG Zi-hui;CAO Yang;CHEN Yun-shuang;ZHANG De-nan;SUN Ying-jie;HUANG Ke-chao(Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin,College of Life Sciences,Guangxi Normal University,Guilin 541006,China;Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain,Guangxi Institute of Botany,Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences,Guilin 541006,China;Guangxi Key Laboratory of Functional Phytochemicals and Sustainable Utilization,Guangxi Institute of Botany,Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences,Guilin 541006,China;College of Environmental Science and Engineering,Guilin University of Technology,Guilin 541006,China)

机构地区：[1]广西师范大学生命科学学院,广西漓江流域景观资源保育与可持续利用重点实验室,桂林541006 [2]广西壮族自治区中国科学院广西植物研究所,广西喀斯特植物保育与恢复生态学重点实验室,桂林541006 [3]广西壮族自治区中国科学院广西植物研究所,广西植物功能物质与资源持续利用重点实验室,桂林541006 [4]桂林理工大学环境科学与工程学院,桂林541006

出　　处：《环境科学》2025年第2期1032-1045,共14页Environmental Science

基　　金：国家自然科学基金项目(42267007);广西重点研发计划项目(桂科AB23026013);广西科学院基本科研业务费项目(CQZ-E-1912);广西漓江流域景观资源保育与可持续利用重点实验室研究基金项目(LRCSU21K0203);广西植物研究所基本业务费项目(桂植业23006);广西喀斯特植物保育与恢复生态学重点实验室基金项目(22-035-26)。

摘　　要：探究连续5 a模拟氮沉降背景下中亚热带桉树人工林土壤有机碳组分和碳库管理指数变化特征及其影响因素,为亚热带森林生态系统的可持续管理提供科学依据.基于2018年建立的桉树人工林模拟氮沉降定位试验,设置对照CK[0 kg·(hm^(2)·a)^(-1)]、低氮LN[50 kg·(hm^(2)·a)^(-1)]、中氮MN[100 kg·(hm^(2)·a)^(-1)]和高氮HN[150 kg·(hm^(2)·a)^(-1)]共4个处理,模拟氮沉降5 a后测定土壤理化性质、碳循环相关酶活性、有机碳组分和碳库管理指数.结果表明:(1)与对照相比,随氮沉降量的增加,土壤有机碳、颗粒有机碳、易氧化有机碳、微生物生物量碳、溶解性有机碳和轻组有机碳在各土层间均趋于增大,重组有机碳则在高氮处理下逐渐减小.(2)氮沉降显著提高了碳库活度指数和碳库管理指数,且随氮输入水平的增加而增大,增强了与碳循环相关的蔗糖酶、淀粉酶和脱氢酶活性,有效提高了土壤碳库质量.(3)有机碳组分与土壤环境因子的相关性和冗余分析结果显示,土壤p H分别与有机碳和活性碳组分之间存在一定的负相关,全氮、速效氮、全钾、速效钾和各交换性离子等指标与有机碳及其组分之间多呈显著或极显著正相关,土壤理化性质和酶活性一定程度上促进了土壤有机碳及其组分含量的提高,交换性氢、速效钾、全钾和淀粉酶是影响土壤有机碳组分和碳库管理指数的主要环境因子.综上,连续5 a模拟氮沉降提高了中亚热带桉树人工林土壤有机碳、活性有机碳组分含量及碳库管理指数,有利于提高土壤肥力,但在高氮[150 kg·(hm^(2)·a)^(-1)]输入量下使重组有机碳含量及碳储量有潜在降低的趋势,长期高氮沉降下可能降低土壤有机碳的稳定性.To study the characteristics of soil organic carbon(SOC)components and carbon pool management indicators of a Eucalyptus plantation after continuously simulating nitrogen deposition for five years and to explore the relationship between soil organic carbon components and soil environmental factors,it is helpful to understand the influence of nitrogen deposition on soil quality and SOC pool stability and provide a scientific basis for sustainable management of subtropical forest ecosystems and protection of the soil environment.In a long-term positioning test of simulating nitrogen deposition from 2018,four different treatments were selected:CK[0 kg·(hm~2·a)~(-1)],low nitrogen LN[50kg·(hm~2·a)~(-1)],middle nitrogen MN[100 kg·(hm~2·a)~(-1)],and high nitrogen HN[150 kg·(hm~2·a)~(-1)].The contents of SOC,light fraction organic carbon(LFOC),heavy fraction organic carbon(HFOC),easily oxidized organic carbon(EOC),dissolved organic carbon(DOC),particulate organic carbon(POC),microbial biomass carbon(MBC),soil physicochemical properties,carbon cycling-related enzyme activity,and carbon pool management indicators following the different treatments were measured.The results showed that:(1)Compared to those in the control,the contents of SOC,DOC,EOC,POC,and MBC increased significantly with the increase in nitrogen deposition.By contrast,HFOC tended to decrease under the higher nitrogen deposition treatment.(2)The input of nitrogen improved the carbon pool activity index and carbon pool management indicators significantly with the increase in nitrogen deposition levels.Nitrogen deposition enhanced the activities of sucrase,amylase,and dehydrogenase related to carbon cycling and improved soil carbon pool quality effectively.(3)The correlation and redundancy analysis between organic carbon components and soil environmental factors showed that soil p H,organic carbon content,and activated carbon components were negatively related.Physical and chemical indicators such as TN,AN,TK,AK,exchangeable ions,etc.,all showed a sig

关 键 词：模拟氮沉降 土壤有机碳组分 活性有机碳 碳库管理指数(CPMI) 桉树人工林 

分 类 号：X144[环境科学与工程—环境科学] X171.1