凋落物及氮添加对针阔叶林土壤氮和水解氨基酸的影响  

Effects of Litter and Nitrogen Addition on Soil Nitrogen and Hydrolyzed Amino Acids Under Coniferous and Broad-leaved Forest

作　　者：廖从梅 王梦思 马红亮[1,2] 高人[1,2] 尹云锋[1,2] LIAO Congmei;WANG Mengsi;MA Hongliang;GAO Ren;YIN Yunfeng(State Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province,Fujian Normal University,Fuzhou 350007,China;School of Geographical Sciences,Fujian Normal University,Fuzhou 350007,China)

机构地区：[1]福建师范大学湿润亚热带山地生态国家重点实验室培育基地,福州350007 [2]福建师范大学地理科学学院,福州350007

出　　处：《土壤》2022年第4期715-722,共8页Soils

基　　金：国家自然科学基金项目(31770659);福建省公益类科研院所专项(2020R1002005)资助。

摘　　要：为探究凋落物对森林土壤氮的影响及氮沉降的调节,本研究以亚热带天然阔叶林(罗浮栲林)和人工针叶林(杉木林)2种林型土壤和凋落物为对象,分别设置土壤(对照)、土壤+凋落物(3倍添加)、土壤+氮(120 mg/kg)、土壤+凋落物(3倍添加)+氮(120 mg/kg)4种处理,每种处理设置3个重复,进行为期一年的室内模拟淋溶试验,分析土壤可溶性氮和物理分级后各粒径土壤水解氨基酸变化。结果表明:与对照比较,阔叶林土壤添加凋落物处理增加土壤铵态氮和游离氨基酸,而降低硝态氮含量;氮添加降低针叶林土壤氨态氮,增加硝态氮含量,但是增加阔叶林土壤铵态氮和游离氨基酸;凋落物添加的情况下,氮添加显著增加阔叶林土壤硝态氮含量。土壤的各粒径组分分布比例差异显著,氮添加倾向于降低针叶林土壤大粒径、增加小粒径分配比例,而阔叶林相反。针叶林土壤添加凋落物显著增加土壤粒径组分2000~250μm、20~2μm、<2μm水解氨基酸含量;氮添加增加针叶林全土、2000~250μm和20~2μm粒径水解氨基酸含量;在凋落物添加或氮添加情况下,氮添加或凋落物显著降低全土、250~53μm、53~20μm粒径水解氨基酸含量。而凋落物和氮添加对阔叶林土壤水解氨基酸含量的影响基本上相反。可见,不同土壤粒径组分水解氨基酸(作为可矿化氮)响应凋落物和氮添加处理的差异,有望作为揭示针阔叶林可溶性氮变化的指标。In order to explore the effect of litter on forest soil nitrogen and the regulation of nitrogen deposition in the subtropical natural broad-leaved forest and artificial coniferous forest,a simulated leaching experiment was conducted for one year,in which four treatments were designed:soil(control),soil with litter addition(3 times litter addition),soil with nitrogen addition(120 mg/kg),and soil with both litter and nitrogen addition(3 times litter addition and N 120 mg/kg),and then soil soluble nitrogen in bulk soil and soil hydrolysis amino acid in different size soil fractions were analyzed.The results showed that compared with control,the addition of broad-leaved forest litter increased soil ammonium nitrogen and free amino acids,but reduced nitrate nitrogen.Nitrogen addition reduced ammonia nitrogen and increased nitrate nitrogen in coniferous forest soil,but increased ammonium nitrogen and free amino acids in broad-leaved forest soil.In the presence of litter,nitrogen addition significantly increased nitrate nitrogen in broad-leaved soil.The proportions of different size soil fractions were found quite different.Nitrogen addition tended to reduce the proportion of the large fractions and increase that of small fractions for coniferous forest soil,which was inverse for broad-leaved forest soils.The addition of coniferous forest litter significantly increased soil hydrolytic amino acid contents in 2000–250μm,20–2μm and<2μm soil fractions.Nitrogen addition increased hydrolytic amino acids in bulk soil,2000–250μm and 20–2μm soil fractions for conifer forest.However,the presence of litter or nitrogen addition,nitrogen addition or litter significantly reduced hydrolyzed amino acids in bulk soil,250–53μm,53–20μm soil fractions,meanwhile the effects of litter and nitrogen addition on hydrolytic amino acids were primarily inverse for broad-leaved forest soils.In conclusion,the responses of hydrolytic amino acids(as mineralized nitrogen)in different size soil fractions are different to the litter an

关 键 词：森林土壤 可溶性碳氮 水解氨基酸 物理分级 

分 类 号：S714[农业科学—林学]