| Drainage is a pilot project for land use and mineral resources development of peatland,and an important way to damage the ecological structure of peatland in China.Drainage caused habitat change,which resulted in significant reduction of CH4 flux and significant increase of CO2 emissions.,located in jingyu county,jilin province,part of the baijiang peat bog was artificially drained in depth in the late 1980 s,in an attempt to promote forest regeneration and rapid tending of the peat bog,and to significantly change the ecological structure of the peat mire.Therefore,this article using static box in growing season-gas chromatography?GC?of natural peat mire and drained peat mire soil CO2 and CH4 emission flux monitoring,simultaneous analysis of soil physical and chemical factors(soil water content?SWC?,soil p H,soil organic carbon?SOC?,total nitrogen?TN?,total phosphorus?TP?and soil enzyme activity??-glucosidase??G?,N-acetylglucosaminidase?NAG?,acid phosphatase?AP?and peroxidase?PER??,The temporal and spatial dynamics of soil CO2 and CH4 emissions from natural peat mire and drained peat mire were discussed,the cumulative emissions of soil CO2 and CH4 during the growing season of natural peat mire and drained peat mire were evaluated,and the emission characteristics of soil CO2 and CH4 emissions from natural peat mire and drained peat mire were clarified,the influencing factors of carbon emission from peat bogs with two different ecological structures were analyzed.The main conclusions are as follows:?1?Environmental factors showed significant spatial heterogeneity in natural peat mire and drained peat mire.Variance analysis showed that among abiotic factors,soil organic carbon?SOC?,soil water content?SWC?and soil p H in natural peat mire were significantly higher than those of ddrained peat mire?p<0.05?,while total nitrogen?TN?and total phosphorus?TP?in natural peat mire were lower than those of drained peat mire?p<0.05?.Among biological factors,the activity of soil enzymes??G,NAG,AP and PER enzymes?in natural peat mire was significantly higher than that in drained peat mire?p<0.05?.?2?The CO2 and CH4 emission fluxes of natural peat mire and drained peat mire show obvious seasonal changes in the growing season.In both natural peat mire and drained peat mire,the minimum value of soil CO2 emission flux appeared in autumn,while the maximum value appeared in August in summer.Among them,the minimum value of CO2 emission flux in natural peat mire soil was 83.99±12.02 mg m-2 h-1,which appeared in October.The maximum value was 517.81±28.41 mg m-2 h-1,which appeared in August.The minimum value of CO2 emission flux in drained peat mire soil was 139.49±0.27 mg m-2 h-1,which also appeared in October.The emission was significantly higher than that of natural peat mire,and the maximum value was 733.78±51.40 mg m-2 h-1,which appearedin August.Obviously,both the maximum and minimum values of CO2 emission fluxes in natural peat mire are smaller than those in drained peat mire.The minimum value of soil CH4 emission all appeared in early spring June,while the maximum value appeared in summer July.Among them,the minimum value of CH4 emission flux in natural peat mire soil is 14.92±6.59 mg m-2 h-1,and the maximum value is 531.64±62.66 mg m-2 h-1.The minimum value of CH4 flux in peat mire soil after drainage was 0.66±0.29 mg m-2 h-1,and the maximum value was 35.30±1.31 mg m-2 h-1.?3?There was obvious heterogeneity in the average and cumulative CO2 and CH4 emission fluxes of natural peat mire and drained peat mire.The average emission flux of soil CO2 in growing season showed drained peat mire > natural peat mire.The average flux of soil CH4 in growing season showed natural peat mire > drained peat mire.The cumulative emission of soil CO2-C in the growing season showed drained peat mire > natural peat mire,while the cumulative emission of soil CH4-C in the growing season showed natural peat mire > drained peat mire.Compared with the cumulative emissions of soil CO2-C and CH4-C in the growing season of baijiang peat mire in two years,the cumulative emissions flux of soil CO2-C(?1.79 ± 0.08?× 106 mg m-2)were higher than those of CH4-C(?0.35 ± 0.03?× 106 mg m-2),the cumulative carbon emission per unit area in the growing season were about?2.14±0.11?×106 mg.?4?the seasonal variation of CO2 emission flux in natural peat mire soil was mainly affected by TP and three hydrolases??G,NAG and AP?.The seasonal variation of CO2 emission flux in drained peat mire was mainly affected by TP,SWC,?G enzymes and AP enzymes.The seasonal variation of CH4 emission flux in natural peat mire soil was mainly affected by TN,TP,?G enzymes,NAG enzymes and PER enzymes.The seasonal variation of CH4 emission flux in drained peat mire was mainly affected by TP,SWC,?G enzymes and NAG enzymes.Drainage has a significant effect on the carbon emission?soil CO2 and CH4?of peat mire soil in Baijianghe peat mire,changbai mountain.Therefore,by studying the differences between natural peat mire and drained peat mire and comparing the drained peat mire with the natural peat mire,this study can provide data support for the ecological recovery of degraded peat mire. |
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