林业科学
林業科學
임업과학
SCIENTIA SILVAE SINICAE
2015年
4期
96-102
,共7页
刘彩霞%焦如珍%董玉红%孙启武%周新华%李峰卿
劉綵霞%焦如珍%董玉紅%孫啟武%週新華%李峰卿
류채하%초여진%동옥홍%손계무%주신화%리봉경
氮沉降%固氮菌%硝酸细菌%亚硝酸细菌%反硝化细菌
氮沉降%固氮菌%硝痠細菌%亞硝痠細菌%反硝化細菌
담침강%고담균%초산세균%아초산세균%반초화세균
nitrogen deposition%azotobacter%nitrobacteria%nitrite bacteria%denitrobacteria
【目的】土壤微生物数量是衡量土壤氮素循环生化功能变化的重要指标。通过野外模拟试验，探讨短期氮沉降中不同氮素形态的沉降量对土壤中可培养固氮菌、硝酸细菌、亚硝酸细菌和反硝化细菌数量的影响，以及初期的变化趋势对森林氮素调控和环境管理的重要意义，为深入研究氮沉降对杉木林森林生态系统的影响提供参考。【方法】2013年5月，在杉木幼龄林内建立30个1 m ×1 m的样方，进行5种氮沉降量[N0(对照)、N1(20 kg· hm －2a －1)、N2(40 kg·hm －2a －1)、N3(60 kg·hm －2a －1)、N4(80 kg·hm －2a －1)]和2种氮形态(I铵态氮、II硝态氮)的模拟沉降试验。分别于2013年6，8，10月从0～10 cm和10～20 cm 土层取样测定微生物数量。固氮菌数量测定采用稀释平板计数法，硝酸和亚硝酸细菌数量采用 MPN-Griess 比色法，反硝化细菌(厌氧)采用酚二磺比色法。【结果】各处理的0～10 cm土层中固氮菌数量均高于10～20 cm 土层；随着氮沉降量增加，可培养固氮菌数量先升高后降低。低于60 kg·hm －2 a －1铵态氮处理有利于固氮菌生长。0～10 cm 土层亚硝酸细菌数量，随铵态氮沉降量增加，先升高再降低最后趋于平缓，在 N1或 N2处理达到最大值；施硝态氮时，菌落数量先降低再升高最终趋于平稳。在6月，虽然铵态氮和硝态氮的氮沉降量相同，但0～10 cm 土层中的亚硝酸细菌数量差异极显著，10～20 cm土层差异显著。8月和10月的硝酸细菌数量变化趋势相同，均为随氮沉降量增加先上升再下降再上升，且在相同氮素沉降量的铵态氮和硝态氮处理间未出现显著差异。反硝化细菌的时间变化与其他菌落不同，施铵态氮时二土层的变化趋势相反，施加硝态氮时反硝化细菌的数量变化较平缓，NO3－-N的 N4处理有轻微抑制作用。【结论】0～10 cm土层的固氮菌数量大于10～20 cm土层，0～60 kg·hm －2 a －1铵态氮和0～80 kg·hm －2 a －1硝态氮均可促进固氮菌的生长。亚硝酸细菌在2种氮形态处理时的变化趋势相反，低铵态氮处理可促进亚硝酸细菌的生长，低硝态氮处理抑制其生长。氮形态对硝酸细菌数量影响不显著，低氮处理促进硝酸细菌数量的增长，而中氮处理开始出现抑制作用。氮沉降量对反硝化细菌影响不显著。
【目的】土壤微生物數量是衡量土壤氮素循環生化功能變化的重要指標。通過野外模擬試驗，探討短期氮沉降中不同氮素形態的沉降量對土壤中可培養固氮菌、硝痠細菌、亞硝痠細菌和反硝化細菌數量的影響，以及初期的變化趨勢對森林氮素調控和環境管理的重要意義，為深入研究氮沉降對杉木林森林生態繫統的影響提供參攷。【方法】2013年5月，在杉木幼齡林內建立30箇1 m ×1 m的樣方，進行5種氮沉降量[N0(對照)、N1(20 kg· hm －2a －1)、N2(40 kg·hm －2a －1)、N3(60 kg·hm －2a －1)、N4(80 kg·hm －2a －1)]和2種氮形態(I銨態氮、II硝態氮)的模擬沉降試驗。分彆于2013年6，8，10月從0～10 cm和10～20 cm 土層取樣測定微生物數量。固氮菌數量測定採用稀釋平闆計數法，硝痠和亞硝痠細菌數量採用 MPN-Griess 比色法，反硝化細菌(厭氧)採用酚二磺比色法。【結果】各處理的0～10 cm土層中固氮菌數量均高于10～20 cm 土層；隨著氮沉降量增加，可培養固氮菌數量先升高後降低。低于60 kg·hm －2 a －1銨態氮處理有利于固氮菌生長。0～10 cm 土層亞硝痠細菌數量，隨銨態氮沉降量增加，先升高再降低最後趨于平緩，在 N1或 N2處理達到最大值；施硝態氮時，菌落數量先降低再升高最終趨于平穩。在6月，雖然銨態氮和硝態氮的氮沉降量相同，但0～10 cm 土層中的亞硝痠細菌數量差異極顯著，10～20 cm土層差異顯著。8月和10月的硝痠細菌數量變化趨勢相同，均為隨氮沉降量增加先上升再下降再上升，且在相同氮素沉降量的銨態氮和硝態氮處理間未齣現顯著差異。反硝化細菌的時間變化與其他菌落不同，施銨態氮時二土層的變化趨勢相反，施加硝態氮時反硝化細菌的數量變化較平緩，NO3－-N的 N4處理有輕微抑製作用。【結論】0～10 cm土層的固氮菌數量大于10～20 cm土層，0～60 kg·hm －2 a －1銨態氮和0～80 kg·hm －2 a －1硝態氮均可促進固氮菌的生長。亞硝痠細菌在2種氮形態處理時的變化趨勢相反，低銨態氮處理可促進亞硝痠細菌的生長，低硝態氮處理抑製其生長。氮形態對硝痠細菌數量影響不顯著，低氮處理促進硝痠細菌數量的增長，而中氮處理開始齣現抑製作用。氮沉降量對反硝化細菌影響不顯著。
【목적】토양미생물수량시형량토양담소순배생화공능변화적중요지표。통과야외모의시험，탐토단기담침강중불동담소형태적침강량대토양중가배양고담균、초산세균、아초산세균화반초화세균수량적영향，이급초기적변화추세대삼림담소조공화배경관리적중요의의，위심입연구담침강대삼목림삼림생태계통적영향제공삼고。【방법】2013년5월，재삼목유령림내건립30개1 m ×1 m적양방，진행5충담침강량[N0(대조)、N1(20 kg· hm －2a －1)、N2(40 kg·hm －2a －1)、N3(60 kg·hm －2a －1)、N4(80 kg·hm －2a －1)]화2충담형태(I안태담、II초태담)적모의침강시험。분별우2013년6，8，10월종0～10 cm화10～20 cm 토층취양측정미생물수량。고담균수량측정채용희석평판계수법，초산화아초산세균수량채용 MPN-Griess 비색법，반초화세균(염양)채용분이광비색법。【결과】각처리적0～10 cm토층중고담균수량균고우10～20 cm 토층；수착담침강량증가，가배양고담균수량선승고후강저。저우60 kg·hm －2 a －1안태담처리유리우고담균생장。0～10 cm 토층아초산세균수량，수안태담침강량증가，선승고재강저최후추우평완，재 N1혹 N2처리체도최대치；시초태담시，균락수량선강저재승고최종추우평은。재6월，수연안태담화초태담적담침강량상동，단0～10 cm 토층중적아초산세균수량차이겁현저，10～20 cm토층차이현저。8월화10월적초산세균수량변화추세상동，균위수담침강량증가선상승재하강재상승，차재상동담소침강량적안태담화초태담처리간미출현현저차이。반초화세균적시간변화여기타균락불동，시안태담시이토층적변화추세상반，시가초태담시반초화세균적수량변화교평완，NO3－-N적 N4처리유경미억제작용。【결론】0～10 cm토층적고담균수량대우10～20 cm토층，0～60 kg·hm －2 a －1안태담화0～80 kg·hm －2 a －1초태담균가촉진고담균적생장。아초산세균재2충담형태처리시적변화추세상반，저안태담처리가촉진아초산세균적생장，저초태담처리억제기생장。담형태대초산세균수량영향불현저，저담처리촉진초산세균수량적증장，이중담처리개시출현억제작용。담침강량대반초화세균영향불현저。
Objective]The number of microorganism in soil is an important index in determining the change of the biochemical function of soil nitrogen cycle. While the current studies mostly focus on the microbial flora,the research on nitrogen cycling associated microorganisms is little. In this paper,the influence of deposition amount of short-term nitrogen deposition in different nitrogen forms on soil culturable azotobacter, nitric acid bacteria, nitrous acid bacteria and denitrifying bacteria is studied by a field simulation experiment. The change trend at early stage in response to the N-deposition is an important knowledge for forest nitrogen regulation and environmental management,and this study would provide reference for the further research on effects of nitrogen deposition on Chinese fir plantation ecosystem.[Method]In May 2013,30 plots of 1 m × 1 m were established in a Cunninghamia lanceolata plantation to simulate nitrogen loadings at 5 levels: N0,N1,N2,N3,and N4 with 0,20,40,60 and 80 kg·hm - 2 a - 1 ,respectively. Soil samples were collected in 0 -10 cm and 10 -20 cm soil layers in June,August and October 2013,respectively. The dilution plate counting method was used to determine the amount of nitrogen fixing bacteria,and the MPN-Griess colorimetry for measuring nitrate and nitrite bacteria,and the phenol two sulfonyl colorimetric method for denitrifying bacteria ( anaerobic) .[Result]The results showed: the amount of azotobacter in the 0-10 cm soil layer was more than in 10 -20 cm. Along with the increase of N deposition,the amount of azotobacter showed a trend that it firstly increased and then decreased. Moreover, ammonium nitrogen deposition(0 -60 kg·hm -2a -1) was in favor of the amount of azotobacter. The amount of nitrite bacteria first increased and then decreased with the increasing ammonium nitrogen,and obtained maximum value in N1 or N2 treatment. The amount of nitrite bacteria showed an almost opposite change patterns in response to nitrate nitrogen addition. In June,nitrite bacteria appeared extremely significant difference with the same ammonium and nitrate nitrogen in 0-10 cm soil layer,and there also was significant difference in 10 -20 cm soil layer. The amount of nitrobacteria showed the same trend in August and October,that was first increase and then decrease and the change showed no significant difference between the two nitrogen forms treatments. The changing trend of denitrobacteria with ammonium nitrogen deposition was opposite between the two soil layers ( 0 - 10 cm,10 - 20 cm ) . Nitrate deposition had no significant effect on denitrobacteria,and the high concentration of nitrogen lightly restrained growth of denitrobacteria.[Conclusion]The amount of azotobacter in 0-10 cm soil layer was greater than that in the 10 -20 cm layer. Ammonium nitrogen (0 -60 kg·hm - 2 a -1) promoted the growth of azotobacter,so did the nitrate nitrogen (0 -80 kg·hm - 2 a -1). For the two nitrogen forms,the trend was inconsistent,low ammonium nitrogen promoted the nitrite bacteria growth,and the low nitrate nitrogen inhibited it. Nitrogen deposition forms had no significant effects on nitrate bacteria,low nitrogen deposition promoted the growth,and the high concentration restrained the growth. The quantity of nitrogen deposition had no significant effect on denitrifying bacteria.
