草业学报
草業學報
초업학보
PRATACULTURAL SCIENCE
2015年
6期
204-212
,共9页
机制%甲烷产生%甲烷氧化%微生物%氮输入
機製%甲烷產生%甲烷氧化%微生物%氮輸入
궤제%갑완산생%갑완양화%미생물%담수입
mechanisms%methane production%methane oxidation%microorganism%nitrogen input
随着人为氮输入的增加,外源氮成为影响土壤甲烷产生、氧化和传输过程的重要因素。土壤甲烷排放受氮素有效性的调节,氮输入会改变土壤初始环境和甲烷排放规律,最终影响甲烷排放量。综述了氮输入对土壤甲烷产生、氧化和传输过程的影响及机制。研究表明,1)氮输入对甲烷排放通量的影响存在促进、抑制和不显著3种情况,这主要是甲烷产生、氧化和传输过程的变化引起的;2)氮输入对甲烷产生过程的影响受产甲烷底物和产甲烷微生物活性的控制,氮输入通过增加土壤有机碳的含量为甲烷产生提供了丰富的底物,同时底物理化性质和植被覆盖度的变化使得这种影响复杂化,氮输入既可促进又可抑制产甲烷菌的活性,并且这种作用受氮形态的影响;3)氮输入对甲烷氧化过程的影响主要是通过刺激或抑制甲烷氧化菌的活性实现的,氮形态的不同也使得这种变化更为复杂;4)氮输入对甲烷传输过程的影响主要受植物通气组织的数量以及传输效率的控制,并且在不同生态系统这种控制作用差异较大。综上所述,氮输入对土壤甲烷产生、氧化和传输过程的影响及机制具有明显的复杂性和不确定性,今后研究中应综合考虑氮输入对甲烷排放关键过程的影响,并侧重于探讨氮输入对相关微生物群落结构、丰度和活性的影响,同时注重对各个生态系统的协同研究,确定氮输入影响下各个生态系统对全球甲烷排放的贡献率。
隨著人為氮輸入的增加,外源氮成為影響土壤甲烷產生、氧化和傳輸過程的重要因素。土壤甲烷排放受氮素有效性的調節,氮輸入會改變土壤初始環境和甲烷排放規律,最終影響甲烷排放量。綜述瞭氮輸入對土壤甲烷產生、氧化和傳輸過程的影響及機製。研究錶明,1)氮輸入對甲烷排放通量的影響存在促進、抑製和不顯著3種情況,這主要是甲烷產生、氧化和傳輸過程的變化引起的;2)氮輸入對甲烷產生過程的影響受產甲烷底物和產甲烷微生物活性的控製,氮輸入通過增加土壤有機碳的含量為甲烷產生提供瞭豐富的底物,同時底物理化性質和植被覆蓋度的變化使得這種影響複雜化,氮輸入既可促進又可抑製產甲烷菌的活性,併且這種作用受氮形態的影響;3)氮輸入對甲烷氧化過程的影響主要是通過刺激或抑製甲烷氧化菌的活性實現的,氮形態的不同也使得這種變化更為複雜;4)氮輸入對甲烷傳輸過程的影響主要受植物通氣組織的數量以及傳輸效率的控製,併且在不同生態繫統這種控製作用差異較大。綜上所述,氮輸入對土壤甲烷產生、氧化和傳輸過程的影響及機製具有明顯的複雜性和不確定性,今後研究中應綜閤攷慮氮輸入對甲烷排放關鍵過程的影響,併側重于探討氮輸入對相關微生物群落結構、豐度和活性的影響,同時註重對各箇生態繫統的協同研究,確定氮輸入影響下各箇生態繫統對全毬甲烷排放的貢獻率。
수착인위담수입적증가,외원담성위영향토양갑완산생、양화화전수과정적중요인소。토양갑완배방수담소유효성적조절,담수입회개변토양초시배경화갑완배방규률,최종영향갑완배방량。종술료담수입대토양갑완산생、양화화전수과정적영향급궤제。연구표명,1)담수입대갑완배방통량적영향존재촉진、억제화불현저3충정황,저주요시갑완산생、양화화전수과정적변화인기적;2)담수입대갑완산생과정적영향수산갑완저물화산갑완미생물활성적공제,담수입통과증가토양유궤탄적함량위갑완산생제공료봉부적저물,동시저물이화성질화식피복개도적변화사득저충영향복잡화,담수입기가촉진우가억제산갑완균적활성,병차저충작용수담형태적영향;3)담수입대갑완양화과정적영향주요시통과자격혹억제갑완양화균적활성실현적,담형태적불동야사득저충변화경위복잡;4)담수입대갑완전수과정적영향주요수식물통기조직적수량이급전수효솔적공제,병차재불동생태계통저충공제작용차이교대。종상소술,담수입대토양갑완산생、양화화전수과정적영향급궤제구유명현적복잡성화불학정성,금후연구중응종합고필담수입대갑완배방관건과정적영향,병측중우탐토담수입대상관미생물군락결구、봉도화활성적영향,동시주중대각개생태계통적협동연구,학정담수입영향하각개생태계통대전구갑완배방적공헌솔。
Methane is an important component of carbon output in anaerobic soil.Minor changes to the soil car-bon cycle will cause significant changes in the metabolic processes involving methane,which in turn can be markedly affected by exogenous nitrogen input.With increase in anthropogenic nitrogen inputs,exogenous ni-trogen becomes an important factor in soil methane production,oxidation,and transmission processes.Meth-ane emissions are regulated by nitrogen availability.Nitrogen inputs can change the background environmentand methane emission mechanisms in soil,and consequently influence methane emission fluxes.Research into effects of nitrogen input on CH4 production and the mechanisms of N effects on oxidation and transport proces-ses in soils are reviewed in this paper.The important findings in the literature are:1)The effects of nitrogen input on CH4 fluxes in soils can be positive,negative or neutral,due to the range of effects of added N on methane production,oxidation,and transport processes;2)The effects of nitrogen input on methane produc-tion processes are controlled by methanogenic substrates and methanogenic microbial activities.Nitrogen input provides rich substrates for methane production by increasing soil organic carbon content.The changes in the physical and chemical properties of substrates and vegetation cover make this effect complicated.Nitrogen in-put can also either promote or inhibit the activity of methanogens,depending on the form of nitrogen supplied;3)The effects of nitrogen input on methane oxidation processes mainly arise from stimulation or inhibition of the activities of methanotrophs;4)The effects of nitrogen input on methane transport processes depend mostly on the number of aerenchyma vessels and on transport efficiencies,and the degree of dependence varied greatly in different ecosystems.Overall,the effects of nitrogen input on soil CH4 production,oxidation,and transport process are complicated and the mechanisms are uncertain.Future research should focus on the effects of nitro-gen input on the critical processes determining methane emissions,on investigation of the effects of nitrogen in-put on microbial community structures,abundance and activities,and on collaborative research in a range of e-cosystems.The goal of future research should be to determine the contribution of various ecosystems to global methane emissions at specific levels of nitrogen input.