连作对杨树人工林土壤呼吸及各组分的影响

发布时间：2018-04-01 06:10

本文选题：自养呼吸　切入点：连作　出处：《中国水土保持科学》2017年01期

【摘要】：土壤呼吸是整个陆地生态系统碳循环的关键过程之一。以山东大汶河沿岸沙地不同连作代数杨树人工林(1代林、2代林和3代林)为研究对象,利用ACE自动土壤呼吸监测系统(UK),对3种林分一个生长季(4—10月)的土壤呼吸速率及温湿度进行测定,同时采用壕沟法对3种林分的土壤呼吸进行组分分离,并对土壤呼吸及各组分与土壤温湿度的关系进行模型模拟。结果表明:3种林分的土壤呼吸速率(RS)、自养呼吸速率(R_A)和异养呼吸速率(RH)的月变化均为明显的单峰格局;生长季内,3种林分R_A贡献率月差异明显,平均贡献率为40.04%;RS及其组分与5 cm处土壤温度存在显著指数关系,与土壤体积含水量没有相关性,土壤温度与土壤体积含水量的复合模型对土壤呼吸速率变化解释能力为80%~94%;3种林分生长季平均土壤呼吸速率分别为3.12、3.08和2.66μmol/(m2·s),3代林RS和RH均显著低于1代林和2代林。连作导致杨树人工林地土壤呼吸速率减弱,土壤理化性质和微生物量的差异是导致林分间土壤呼吸速率差异的主要原因。揭示连作对杨树人工林土壤呼吸及各组分的影响,以及作用机制,为全面探究杨树人工林连作效应及土壤碳循环,提供数据支撑。
[Abstract]:Soil respiration is one of the key processes of carbon cycle in the whole terrestrial ecosystem. ACE automatic soil respiration monitoring system was used to measure the soil respiration rate and temperature and humidity of three stands in a growing season from April to October. At the same time, the soil respiration components of three stands were separated by trench method. The relationship between soil respiration and soil temperature and humidity was simulated. The results showed that the monthly variations of soil respiration rate (RSN), autotrophic respiration rate (RA) and heterotrophic respiration rate (RH) of three species of stands were all single peak. In the growing season, the RIA contribution rate of the three stands was significantly different, the average contribution rate was 40.04% and there was a significant exponential relationship between RS and soil temperature at 5 cm, but there was no correlation between the RIA contribution rate and the soil volume water content. The composite model of soil temperature and soil volume water content can explain the change of soil respiration rate. The average soil respiration rate of the three stands is 3.123.08 and 2.66 渭 mol/(m2 / s respectively, which is significantly lower than that of the first and second generation forest. Continuous cropping resulted in the decrease of soil respiration rate in poplar plantations. The difference of soil physical and chemical properties and microbial biomass was the main cause of the difference of soil respiration rate among stands. The effects of continuous cropping on soil respiration and its components in poplar plantation were revealed, and the mechanism of action was also revealed. To provide data support for exploring the continuous cropping effect and soil carbon cycle of poplar plantation.
【作者单位】：泰山森林生态系统国家定位观测研究站山东农业大学农业生态与环境重点实验室;
【基金】：国家林业公益性科研专项“森林生态服务功能分布式定位观测与模型模拟”(201204101-7) 国家自然科学基金“黄泛平原农田林网的生态因子场形成机制的研究”(31170662) 教育部博士点基金“基于生态因子场的拟法正农田林网可持续更新机制研究”(20133702110007)
【分类号】：S714

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