摘要
土壤氮循环是森林生态系统主要的生物地球化学过程之一,具有重要的环境效应.本研究以长白山阔叶红松林为对象,通过人工氮添加和透明V型板截雨模拟氮沉降(NF)、降水减少(RR)以及两者交互作用(RF),分析了土壤硝化作用、反硝化作用,以及硝化功能微生物(氨氧化古菌(nifH)AOA和氨氧化细菌AOB)、反硝化功能微生物(nirK、nirS和nosZ)和固氮功能微生物对NF、RR及RF作用的响应.结果表明:土壤硝化作用与土壤NH+4-N、反硝化作用与土壤NO-3-N含量呈显著正相关关系;土壤硝化作用和反硝化作用未因3种处理而发生显著变化,反硝化作用表现出明显的季节性动态变化;长期RR处理抑制了长白山阔叶红松林土壤净硝化作用,NF和RF处理则促进了其净硝化作用;nifH和nosZ菌群具有较强的抗胁迫能力,其多样性不易受氮水变化影响,干旱条件下nirK群落组成更容易受氮沉降影响;AOA对干旱具有较高敏感性,AOB对NF和RF处理具有较高敏感性.3种处理可不同程度影响土壤净硝化作用,并改变AOB、AOA和nirK基因反硝化微生物多样性,进而可能影响森林土壤含氮气体释放并改变森林生态系统服务.
Soil nitrogen（N） cycling, one of the most important biogeochemical processes in forest ecosystems, has significant environmental effects. However, little is known about how it responds to N deposition and precipitation changes. Here, we examined the main effects of N deposition（NF）,rainfall reduction（RR） and their interactive effect（RF） on soil N cycling by N addition and trans-parent V-shaped board interception in a broad-leaved Korean pine forest in Changbai Mountains.The responses of soil nitrification, denitrification, nitrifying functional genes（ ammonia-oxidizing archaea AOA and ammonia-oxidizing bacteria AOB）, denitrifying functional genes（nirK,nirS and nosZ） and N fixing function genes（nifH） to NF, RR and RF treatments were analyzed. We found significant positive correlations between nitrification and soil NH4^＋-N, denitrification and and NO3^--N,respectively. Soil nitrification and denitrification were not significantly influenced by the three treatments, while denitrification showed an obvious seasonal dynamics. Long-term RR treatment inhibited soil net nitrification, while NF and RF treatments promoted soil net nitrification;nifH and nosZ genes of bacteria were strong resistant to stress, and their diversity was not susceptible to the changes of N and rainfall. Under drought condition,nirKgene of soil bacteria was more susceptible to N deposition. AOA had a higher sensitivity to drought, while AOB had higher sensitivity to NF and RF treatments. The three treatments affected soil net nitrification and altered the diversity ofAOB, AOA and nirK-harboring denitrifier in varying degrees, which might affect the release of N-containing gas and ecosystem services.
作者
徐婷婷
郑俊强
韩士杰
张凤丽
王秀秀
XU Ting-ting;ZHENG Jun-qiang;HAN Shi-jie;ZHANG Feng-li;WANG Xiu-xiu(Key Laboratory of Forest Ecology and Management,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China;University of Chinese Academy of Sciences,Beijing 100049,China;Henan University,Kaifeng 475004,Henan,China;Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China;Changbai Mountains Forest Ecosystem Research Station,Antu 133613,Jilin,China）.)
出处
《应用生态学报》
CAS
CSCD
北大核心
2018年第9期2797-2807,共11页
Chinese Journal of Applied Ecology
基金
国家重点基础研究发展计划项目(2014CB954400)
国家自然科学基金项目(41473077
41673077)资助~~
关键词
长白山阔叶红松林
氮沉降
降水变化
土壤氮循环
微生物功能多样性
broad-leaved Korean pine forest in Changbai Mountains
nitrogen deposition
precipitation change
soil nitrogen cycle
microbial functional diversity.
