To examine carbon(C) mineralization and microbial activities of different soil types under different levels of exogenous nitrogen(N) availabilities,three types of soil were collected from continuous permafrost,island permafrost and seasonally frozen ground,and incubated under laboratory conditions from June to October in 2010.The experiment was designed with four N levels,the amounts of exogenous N were 0(N0),0.1 mg/g(N1),0.2 mg/g(N2),0.5 mg/g(N3).The results indicated that the cumulative C mineralization of three types of soil under N0 treatment was 5 646 mg/kg,2 103 mg/kg and 1 287 mg/kg,respectively,which existed positive correlation with initial amount of soil organic C,total N and microbial carbon(MBC) in the end of incubation.The C mineralization rates and amount of cumulative mineralization of three types of soil under N0 treatment were all higher than under N treatment,indicated that exogenous N suppressed soil C mineralization.As the amount of exogenous N increasing,the inhibition of N on cumulative mineralization of different soil types was various.There was no significant difference of cumulative C mineralization of permafrost soil among three N treatments;the cumulative mineralization of island permafrost between N1 and N2 treatment was similar,but was all higher than N3 treatment;the difference of cumulative mineralization of seasonally frozen ground between N2 and N3 treatment was not notable,but was all lower than N1 treatment.After incubation,the values of MBN decreased and MBC/MBN increased along with exogenous N increasing.The cumulate mineralization of seasonal frozen soil positively related with MBN,and negatively related with MBC/MBN,which indicated that nitrogen availability may affect the carbon mineralization by changing microbial structure and composition.
LI Ying-chen, SONG Chang-chun, HOU Cui-cui, WANG Xian-wei, SUN Xiao-xin
. Effects of Exogenous Nitrogen Availability on Carbon Mineralization of Different Wetland Soil Types in Northeast China[J]. SCIENTIA GEOGRAPHICA SINICA, 2011
, 31(12)
: 1480
-1486
.
DOI: 10.13249/j.cnki.sgs.2011.012.1480
[1] Intergovernmental Panel on Climate Change WGI.Fourth As-sessment Report,Climate Change 2007:The Physical Science Basic[C].Cambrige:Cambridge University Press,2007.
[2] Houghton J T,Ding Y,Griggs D J,et al.Climate change 2001: the scientific basis third IPCC report[C].Cambrige:Cam-bridge University Press,2001.
[3] Mack M C,Schuur E A G,Bret-Harte M S,et al.Ecosystem car-bon storage in arctic tundra reduced by long-term nutrient fertil-ization[J].Nature,2004,431:440-443.
[4] Gorham E.Northern peatlands:role in the carbon cycle and probable responses to climate warming[J].Ecological Applica-tions,1991,1:182-195.
[5] Allison S D,LeBauer D S,Ofrecie M R,et al.Low levels of ni-trogen addition stimulate decomposition by boreal forest fungi[J].Soil Biology and Biochemistry,2009,41:293-302.
[6] 刘德燕,宋长春,王丽,等.外源氮输入对湿地土壤有机碳矿化及可溶性有机碳的影响[J].环境科学,2008,29(12):3525~ 3530.
[7] Neff J C,Townsend A R,Gleixner G,et al.Variable effects of nitrogen additions on the stability and turnover of soil carbon[J].Nature,2002,419:915-917.
[8] Aerts R,Logtestijn R V,Staalduinen M V,et al.Nitrogen supply effects on productivity and potential leaf litter decay of Carex species from peatlands differing in nutrient limitation[J].Oeco-logia,1995,104:447-453.
[9] Hartley I P,Hopkins D W,Sommerkorn M,et al.The response of organic matter mineralization to nutrient and substrate addi-tions in sub-arctic soils[J].Soil Biology and Biochemistry. 2010,42:92-100.
[10] 刘兴土.东北湿地[M].北京:科学出版社,2005.
[11] 秦大河,陈宜瑜,李学勇.中国气候与环境演变(下卷):气候与环境变化的影响与适应,减缓对策[M].北京:科学出版社.
[12] 金会军,王绍令,吕兰芝,等.兴安岭多年冻土退化特征[J].地理科学,2009,29(2):223~228.
[13] Hobbie S E,Nadelhoffer K J,Högberg P.A synthesis:the role of nutrients as constrains on carbon balances in boreal and arc-tic regions[J].Plant and Soil,2002,242:163-170.
[14] Allison S D,Czimczik C L,Treseder K K.Microbial activity and soil respiration under nitrogen addition in Alaskan boreal forest[J].Global Change Biology,2008,14:1156-1168.
[15] Mikan J C,Schimel J P,Doyle A P.Temperature controls of mi-crobial respiration in arctic tundra soils above and below freez-ing[J].Soil Biology and Biochemistry,2002,34,1785-1795.
[16] Wang X W,Li X Z,Hu Y M,et al.Potential carbon mineraliza-tion of permafrost peatlands in Great Hing’an Mountains,Chi-na[J].Wetlands,2010,30:747-756.
[17] Mack M C,Schuur E A G,Bret-Harte M S et al.Ecosystem car-bon storage in arctic tundra reduced by long-term nutrient fertil-ization[J].Nature,2004,431:440-443.
[18] 鲁如坤.土壤农业化学分析方法[M].北京:中国农业科技出版社,2000:156~157,159~162.
[19] 刘德燕,宋长春.磷输入对湿地土壤有机碳矿化及可溶性碳组分的影响[J].中国环境科学,2008,28(9):769~774.
[20] Davidson E A,Janssens I A.Temperature sensitivity of soil car-bon decomposition and feedbacks to climate change[J].Na-ture,2006,440:165-173.
[21] Hopkins D W,Sparrow A D,Elberling B,et al.Carbon,nitro-gen and temperature controls on microbial activity in soils from an Antarctic dry valley[J].Soil Biology and Biochemistry, 2006,38:3130-3140.
[22] 陈涛,郝晓晖,杜丽君,等.长期施肥对水稻土土壤有机碳矿化的影响[J].应用生态学报,2008,19(7):1494~1500.
[23] Ågren G,Bosatta E,Magill A H.Combining theory and experi-ment to understand effects of inorganic nitrogen on litter de-composition[J].Oecologia,2001,128:94-98.
[24] Craine J M,Morrow C,Fierer N.Microbial nitrogen limitation increases decomposition[J].Ecology,2007,88(8):2105-2113.
[25] Weand M P,Arthur M A,Lovett G M,et al.Effects of tree spe-cies and N additions on forest floor microbial communities and extracellular enzyme activities[J].Soil Biology and Biogeo-chemistry,2010,42:2161-2173.
[26] Bradley K,Drijber R A,Knops J.Increased N availability in grassland soils modifies their microbial communities and de-creases the abundance of arbuscular mycorrhizal fungi[J].Soil Biology and Biogeochemistry,2006,38:1583-1595.
[27] Hobbie S E,Vitousek P M.Nutrient limitation of decomposi-tion in Hawaiian forests[J].Ecology,2000,81:1867-1877.
[28] Weintraub M N,Schimel J P.Nitrogen mineralization and soil organic matter chemistry in Arctic tundra soil[J].Ecosystem, 2003,6:129-143.
[29] Aerts R,Van Logtestijn R S P,Karlsson P S.Nitrogen supply differentially affects litter decomposition rates[J].Oecologia, 2006,146:652-658.
