桉树人工林土壤呼吸昼夜变化及其对环境因子的响应  

Diurnal Variation of Soil Respiration in EucalyptusPlantationsand Its Response to Environmental Factors

作　　者：竹万宽[1] 王志超[1] 黄润霞 许宇星[1] ZHU Wankuan;WANG Zhichao;HUANG Runxia;XU Yuxing(Research Institute of Fast-growing Trees,Chinese Academy of Forestry/National Positioning Observation and Research Station of EucalyptPlantationEcosystem,Zhanjiang 524022,Guangdong,China)

机构地区：[1]中国林业科学研究院速生树木研究所/广东湛江桉树林生态系统国家定位观测研究站,广东湛江524022

出　　处：《桉树科技》2024年第2期32-38,共7页Eucalypt Science & Technology

基　　金：广东省林业科技创新项目(2022KJCX020);广东湛江桉树林生态系统国家定位观测研究站运行补助项目(KS2024160017);林业生态监测网络平台运行项目数据采集(2024CG232)。

摘　　要：以雷州半岛地区尾叶桉人工林为研究对象,采用LI-8150土壤碳通量测量系统,连续测定其土壤呼吸速率及相关环境因子的昼夜变化规律,分析土壤呼吸的时间变化特征及其对环境因子变化的响应,旨在为桉树人工林生态系统土壤碳排放估算提供数据支持。结果表明:尾叶桉人工林土壤呼吸速率昼夜变化为双峰趋势,最大值和最小值分别在4:00和16:00取得,分别为3.95μmol·m^(-2)·s^(-1)和3.29μmol·m^(-2)·s^(-1),日均值为3.61μmol·m^(-2)·s^(-1)。从昼夜变化来看,土壤呼吸与土壤温度、土壤热通量呈极显著负相关。从月变化来看,土壤呼吸与土壤温、湿度均存在极显著正相关关系。土壤日碳排放量为2.59~4.56 g·m^(-2)。可见,对人工林土壤碳排放进行估算时应考虑不同时间尺度环境因子对土壤呼吸影响的方向和强度。The LI-8150 Soil Carbon Flux Measurement System was used to continuously measure the diurnal changes of soil respiration rate and related environmental factors in a Eucalyptus urophylla plantation in the Leizhou Peninsula.This provided data for analyses of diurnal and nocturnal characteristics of soil respiration and its response to the changes of environmental factors,with the aim of supporting estimation of soil carbon emissions in plantation forest ecosystems.The results showed that the daily variation of soil respiration rates in the eucalypt plantation followed a bimodal pattern,with the maximum and minimum values of 3.95μmol·m^(-2)·s^(-1) and 3.29μmol·m^(-2)·s^(-1) at 4:00 am and 16:00 pm,respectively,and a daily mean value of 3.61μmol·m^(-2)·s^(-1).In terms of diurnal variations,soil respiration showed a significant negative correlation with the temperature and soil heat flux.In terms of monthly variation,soil respiration was highly,significantly and positively correlated with soil temperature and moisture.The daily soil carbon emissions ranged from 2.59 to 4.56 g·m^(-2).When estimating soil carbon emissions,it is important to consider the direction and intensity of environmental factors'effects on soil respiration at different time scales.

关 键 词：桉树人工林 土壤呼吸 昼夜变化 环境因子 

分 类 号：S714.5[农业科学—林学]