温度对兰州市南北两山5种典型人工林土壤氮素硝化潜力的影响  

Effect of temperature on soil nitrogen nitrification potential in five typical artificial forests across the northern and southern mountains of Lanzhou city

作　　者：席杰 刘小娥[1] 苏世平[1] 张龚 唐维春 师微柠 XI Jie;LIU Xiaoe;SU Shiping;ZHANG Gong;TANG Weichun;SHI Weining(College of Forestry,Gansu Agricultural University,Lanzhou 730070,China;Forestry and Grassland Service Center of Tongwei County,Gansu,Tongwei,743300,China)

机构地区：[1]甘肃农业大学林学院,甘肃兰州730070 [2]通渭县林业和草原服务中心,甘肃通渭743300

出　　处：《甘肃农业大学学报》2024年第5期260-267,276,共9页Journal of Gansu Agricultural University

基　　金：甘肃农业大学科技创新基金-青年导师扶持基金项目(GAU-QDFC-2022-17);甘肃省高等学校青年博士基金项目(2022QB-081);甘肃省自然科学基金(21JR7RA814)。

摘　　要：【目的】旨在探究随着温度的变化,土壤氮素硝化量和硝化速率的变化机理。【方法】以兰州市南北两山5种典型人工林(新疆杨林、侧柏林、刺槐林、新疆杨-刺槐混交林、侧柏-刺槐混交林)土壤为研究对象,通过间歇性好氧淋洗法在室内培养,研究在不同温度(15、25、35℃)下,5种典型人工林土壤的氮素硝化特征。【结果】在前期培养内(0~7 d),在同一温度下(35℃),侧柏刺槐混交林的土壤氮素硝化速率最大,分别比新疆杨刺槐混交林、新疆杨林、侧柏林和刺槐林高8.8%、62.6%、64.8%、77.0%。在15~35℃温度范围内,随着温度的升高,5种林分的硝化速率和硝化量均增加;在整个培养期(84 d)内,5种林分的硝化量在35℃达到最大,在0~20 cm和20~40 cm土层,五种林分的硝化量均值表现为35℃>25℃>15℃,且侧柏刺槐混交林的土壤氮素硝化量最大,分别比新疆杨刺槐混交林、刺槐林、新疆杨林和侧柏林高2.5%、13.2%、28.7%、40.8%。【结论】在所有土层中新疆杨-刺槐混交林的土壤硝态氮含量最高,5种林分土壤硝态氮含量和硝化速率随着温度的增加而增加,随土层的加深而降低,且混交林的硝化量和硝化速率均显著高于纯林;各林分敏感性均表现为25℃/15℃>35℃/25℃。【Objective】This study was conducted to explore the mechanism underlying the variation in soil nitrogen nitrification and its nitrification rate with temperature change.【Method】The soils were sampled from five typical artificial forest(i.e.,Populus alba var pyramidalis plantation,Platycladus orien-talis plantation,Robinia psrudoacia plantation,P.alba var pyramidalis+R.psrudoacia plantation,P.ori-entalis+R.psrudoacia plantation),and then were cultured in laboratory by the way of intermittent aerobic leaching,followed by determining the characteristics of their nitrogen nitrification at varying temperatures(15,25,and 35℃).【Result】In the initial cultivation phase(0~7 days)at a consistent temperature of 35℃,the soil nitrogen nitrification rate under the P.orientalis+R.pseudoacacia plantation displayed the highest nitrification rate,which was 8.8%,62.6%,64.8%,and 77.0%higher than those observed under P.alba var pyramidalis+R.pseudoacacia plantation,P.alba var pyramidalis plantation,P.orientalis plantation,and R.pseudoacacia plantation,respectively.Across the temperature spectrum of 15~35℃,there was an escalation in both nitrification rate and nitrification volume across the five stands.Throughout the entire cultivation period(84 days),the nitrification volume peaked at 35℃across the five stands,with the mean nitrification volume ranking as 35℃>25℃>15℃in the 0~20 cm and 20~40 cm soil layers.Notably,the soil nitrogen nitrification in the P.orientalis+R.psrudoacia plantation demonstrated the highest levels,which was 2.5%,13.2%,28.7%,and 40.8%higher than that of P.alba var pyramidalis+R.psrudoacia plantation,R.psrudoacia plantation,P.alba var pyramidalis plantation,and P.orientalis plantation,respectively.【Conclusion】In each of soil layers,the nitrate nitrogen content was the highest in P.alba var pyramidalis+R.psrudoacia plantation.The nitrate content and nitrification rate increased with temperature rising,and decreased with soil depth.Both the nitrification volume and nitrification rate in

关 键 词：温度 土壤氮素硝化 林分类型 兰州市南北两山 

分 类 号：S153.61[农业科学—土壤学]