模拟氮沉降对土壤酸化及土壤酸缓冲能力的影响  

Effects of Simulated Nitrogen Deposition on Soil Acidification and Soil Buffering Capacity

作　　者：胡波[1] 王云琦[1] 王玉杰[1] 王彬[1] 张会兰[1] 郭平[1] 刘春霞[1] 

机构地区：[1]北京林业大学,水土保持与荒漠化防治教育部重点实验室,北京100083

出　　处：《环境科学研究》2015年第3期418-424,共7页Research of Environmental Sciences

基　　金：国家自然科学基金项目(31100515);高等学校博士学科点专项科研基金项目(20110014120001)

摘　　要：为探讨N沉降对酸雨区森林土壤酸化和土壤酸缓冲能力的影响,于2012年4—12月在重庆缙云山地区选取针阔混交林和常绿阔叶林2种典型林分进行模拟N沉降试验,设N0、N1、N2、N3 4个处理,施N量(模拟N沉降量)分别为0、60、120、240kg/(hm2·a),每月月初将NH4NO3溶液均匀喷洒在所选样方内,8个月后进行取样分析.结果表明:1不同p H下2种林分土壤的酸缓冲能力存在较大差异,p H越低土壤酸缓冲能力越高.22种林分的土壤酸缓冲能力随N沉降量的增加而降低.在相同的N沉降量下,常绿阔叶林土壤酸缓冲能力略高于针阔混交林.3N沉降会加快土壤酸化速率.与N0处理相比,N1、N2、N3处理常绿阔叶林土壤p H分别下降了0.03、0.06、0.16,而针阔混交林则分别下降了0.08、0.10、0.26.42种林分土壤中盐基离子含量均随N沉降量的增加而降低,交换性Al3+含量则相反.与N0处理相比,常绿阔叶林N1、N2、N3处理盐基离子含量分别下降了55.76%、66.00%、70.38%,交换性Al3+含量分别增加了16.03%、21.37%、31.81%;针阔混交林盐基离子含量分别下降了24.12%、43.38%、62.24%,交换性Al3+含量分别增加了19.19%、23.48%、34.85%.研究表明,氮沉降会降低森林土壤酸缓冲能力,加快酸化速率,并且常绿阔叶林土壤对N沉降的敏感性高于针阔混交林.To investigate the effects of N deposition on soil acidification and acid buffering capacity of forestry soil leached by long-term acid rain,a simulated N decomposition experiment was conducted in two typical respective stands of theropencedrymion forest and evergreen broadleaf forest in Jinyun Mountain from April to December 2012.Four N decomposition levels were designed： N0（ 0 kg/（ hm^2·a））,N1（ 60 kg/（ hm^2·a））,N2（ 120 kg/（ hm^2·a）） and N3（ 240 kg/（ hm^2·a））.Samples were collected and analyzed eight months later.The results showed that： 1） The lower the soil p H was,the higher acid the buffering capacity gained.2） Soil acid buffering capacity of the two stands decreased as the amount of N deposition increased.The soil acid buffering capacity of the evergreen broadleaf forest was slightly higher than the theropencedrymion under the same N deposition.3） N deposition accelerated the rate of soil acidification.Compared with N0,soil p H values of the evergreen broadleaf forest decreased by 0.03,0.06 and 0.16 in N1,N2 and N3,while in theropencedrymion they decreased 0.08,0.10 and 0.26,respectively.4） Compared with N0,the base cations of the evergreen broadleaf forest were reduced by 55.76%,66.00% and 70.38% in N1,N2 and N3,respectively,while Al3 ＋increased by 16.03%,21.37%and 31.81%,respectively.Compared with N0,the base cations of the theropencedrymion forest were reduced by 24.12%,43.38% and62.24% in N1,N2 and N3,respectively,while Al3 ＋increased by 19.19%,23.48% and 34.85%,respectively.The results showed that N deposition decreased acid buffering capacity of the forest soil and accelerated the rate of soil acidification.Evergreen broadleaf forest had a higher susceptibility to N deposition than theropencedrymion.

关 键 词：氮沉降 土壤酸化 土壤酸缓冲能力 盐基离子 

分 类 号：X53[环境科学与工程—环境工程]