摘要
本研究以温带森林土壤为研究对象,设置野外模拟氮沉降实验,分析不同施氮形态和施氮水平对微生物群落结构的影响。试验设置对照(Control,0 kg N·hm^(-2)·a^(-1))、混合态低氮(NH_4NO_3,50 kg N·hm^(-2)·a^(-1))、混合态高氮(NH_4NO_3,150 kg N·hm^(-2)·a^(-1))、铵态氮低氮((NH_4)_2SO_4,50 kg N·hm^(-2)·a^(-1))、铵态氮高氮((NH_4)_2SO_4,150 kg N·hm^(-2)·a^(-1))、硝态氮低氮(NaNO_3,50 kg N·hm^(-2)·a^(-1))、硝态氮高氮(NaNO_3,150 kg N·hm^(-2)·a^(-1))7种氮处理,持续施氮3年后,运用磷脂脂肪酸(PLFA)法对土壤微生物群落结构进行测定。结果表明:在不同水平的氮添加下,土壤微生物总量、细菌、土壤革兰阳性细菌(G+细菌)、土壤革兰阴性细菌(G-细菌)和真菌的PLFA含量均随施氮水平的增加而升高;在不同形态的氮添加下,混合态氮添加提高了微生物总量、细菌、真菌和放线菌的PLFA含量。主成分分析(PCA)表明,除铵态氮低氮添加样地外,其他氮添加处理样地中的土壤微生物结构都发生了改变。这些结果表明,模拟大气氮沉降初期,氮添加会增加温带森林土壤微生物生物量,达到一定水平后会改变土壤微生物群落结构。
Atmospheric nitrogen （N） deposition is a serious threat to global ecosystems. Soil microbes are sensitive to environmental changes. Investigating the effects of N deposition on soil mi- crobial community structure may provide theoretical basis for scientific management of forest eco- systems. A manipulative field experiment was conducted to investigate the effects of different forms （NH4N03, （NH4）2S04, NAN03） and different levels （0, 50, 150 kg N ~ hm-2 ~ a-r） of N addition on the microbial community structure in a temperate forest soil. Soil microbial commu- nity structure was measured using the method of phospholipid fatty acid analysis （PLFA） after three consecutive years of N addition treatments. Our results showed that the amounts of total PLFA, bacterial PLFA, G~ bacterial PLFA, G- bacterial PLFA and fungal PLFA in N addition plots were significantly higher than that in control plots, and N addition increased the amount of microbial PLFA significantly in the order of high N addition 〉 low N addition 〉 control. The amounts of total PLFA, bacterial PLFA, fungal PLFA and actinomyces PLFA in NH4NO3-N ad- dition plots were generally higher than that in NaNO3-N addition and （ NH4 ） 2 S04-N addition plots at the same N addition level. Principal component analysis （PCA） showed that microbial community structures were changed in all N-added plots except the low （NH4） 2SO4-N addition plots. Overall, these results suggested that N addition would increase soil microbial biomass and change soil microbial community structure in forest soils when N addition level reaches a threshold, at least over the short term.
作者
许可
王春梅
张艺
杨欣桐
刘卫敏
XU Ke WANG Chun-mei ZHANG Yi YANG Xin-tong LIU Wei- min(College of Environmental Science ＆ Engineering, Belting Forestry University, Beijing 100083, China）.)
出处
《生态学杂志》
CAS
CSCD
北大核心
2016年第10期2676-2683,共8页
Chinese Journal of Ecology
基金
中央高校基本科研业务费专项项目(2016JX02)
国家自然科学基金项目(41373069)资助
关键词
氮添加
温带森林土壤
磷脂脂肪酸
微生物群落结构
nitrogen addition
temperate forest soil
phospholipid fatty acids
soil microbial community structure
