神农架大九湖泥炭湿地水汽通量特征及生态意义
|
摘要
采用涡度相关法对神农架大九湖泥炭湿地生态系统2015年8月至2016年7月的水汽通量进行观测,研究了大九湖湿地水汽通量的变化规律及其主要环境影响因子。结果表明:大九湖湿地水汽通量具有明显的日变化和季节变化,均呈单峰曲线,即在月尺度上,日变化范围为-0.63(5月份)~6.95(7月份)mmol/(s·m~2),白天变化幅度较大,夜间基本维持在0左右,在季节尺度上,夏季日变化最为明显,冬季最弱,生态系统整体表现为水汽源;大九湖湿地全年蒸散量(1 133.88mm)占降雨量(2 096.97mm)的54.07%,表明降雨量能满足目前生态系统的需求;大九湖湿地水汽通量主要受净辐射(Rn)和饱和水汽压差(VPD)的共同影响,即湿地春、夏、秋、冬四季水汽通量与Rn两者拟合的R~2值分别为0.682 3、0.753 4、0.638 4、0.284 7,均优于其他研究区域,可能与泥炭湿地常年积水以及亚高山地区辐射较强有关;大九湖湿地植物主要生长季内(6~9月份)水汽通量与VPD的相关性分析显示,在泥炭藓生长季初期和末期(6、7、9月份),其叶片易受到水分胁迫,水汽通量随VPD先增加后减小,而在泥炭藓生长季中期(8月份),其发育成熟,水汽通量随VPD的增加而增大,两者的拟合效果也达到最佳(R~2=0.408 4)。该研究结果可为该区域水热评估及气候预测提供基础数据。
By adopting eddy covariance technique,this paper analyzes the water vapor flux and its controlling environmental factors from August 2015 to July 2016 in the peat wetlands of Dajiuhu,Shennongjia,which can provide the scientific data for hydrothermal assessment and climate prediction in the region.The results show that the water vapor flux had distinct diurnal and seasonal variations marked by a single-peak type.Daily changes ranged from-0.63mmol/(s·m~2)(May)to 6.95mmol/(s·m~2)(July),and great changes happened during the daytime,and kept 0at nighttime.Of four seasons,greatest changes happened in summer,and the change amplitude of winter is the lowest.On the whole,Dajiuhu peat ecosystem was the source of water vapor.The annual evapotranspiration(1133.88mm)accounted for 54.07% of the precipitation(2 096.97mm).In addition,evapotranspiration was less than precipitation in the most of months,which indicated that the precipitation can meet the water demands of Dajiuhu peat ecosystem.The water vapor flux is mainly controlled by the net radiation(Rn)and the vapor pressure deficit(VPD).There was a good correlation between water vapor flux and Rn,and the squares of coefficients(R~2)were 0.682 3in spring,0.753 4in summer,0.638 4in autumn and 0.284 7in winter.Our results were better than those of the other study area,which might result from the perennial water and strong radiation in the Dajiuhu area.In the early and late growth of Sphagnum(June,July,September),water vapor flux first increased then decreased with the increase of VPD for Sphagnum leaves were susceptible to water stress.During the middle of the growing season(August),the physiological condition of Sphagnum was mature,and water vapor flux increased with the increase of VPD,showing the best fitting effect(R~2=0.408 4).
By adopting eddy covariance technique,this paper analyzes the water vapor flux and its controlling environmental factors from August 2015 to July 2016 in the peat wetlands of Dajiuhu,Shennongjia,which can provide the scientific data for hydrothermal assessment and climate prediction in the region.The results show that the water vapor flux had distinct diurnal and seasonal variations marked by a single-peak type.Daily changes ranged from-0.63mmol/(s·m~2)(May)to 6.95mmol/(s·m~2)(July),and great changes happened during the daytime,and kept 0at nighttime.Of four seasons,greatest changes happened in summer,and the change amplitude of winter is the lowest.On the whole,Dajiuhu peat ecosystem was the source of water vapor.The annual evapotranspiration(1133.88mm)accounted for 54.07% of the precipitation(2 096.97mm).In addition,evapotranspiration was less than precipitation in the most of months,which indicated that the precipitation can meet the water demands of Dajiuhu peat ecosystem.The water vapor flux is mainly controlled by the net radiation(Rn)and the vapor pressure deficit(VPD).There was a good correlation between water vapor flux and Rn,and the squares of coefficients(R~2)were 0.682 3in spring,0.753 4in summer,0.638 4in autumn and 0.284 7in winter.Our results were better than those of the other study area,which might result from the perennial water and strong radiation in the Dajiuhu area.In the early and late growth of Sphagnum(June,July,September),water vapor flux first increased then decreased with the increase of VPD for Sphagnum leaves were susceptible to water stress.During the middle of the growing season(August),the physiological condition of Sphagnum was mature,and water vapor flux increased with the increase of VPD,showing the best fitting effect(R~2=0.408 4).
引文
[1]Baldocchi D D,Falge E,Gu L,et al.FLUXNET:A new tool to study the temporal and spatial variability of ecosystem-scale carbon dioxide,water vapor,and energy flux densities[J].Bulletin of the American Meteorological Society,2001,82(11):2415-2434.
[2]张小斌,李新.我国水环境安全研究进展[J].安全与环境工程,2013,20(1):122-125,137.
[3]欧阳峰,陆一新,黄冬梅.水污染造成的环境经济损失分析[J].安全与环境工程.2006,13(1):33-36.
[4]刘玉莉,江洪,周国模,等.安吉毛竹林水汽通量变化特征及其与环境因子的关系[J].生态学报,2014,34(17):4900-4909.
[5]牛晓栋,江洪,方成圆,等.天目山常绿落叶阔叶混交林生态系统水汽通量特征[J].浙江农林大学学报,2016,33(2):216-224.
[6]杨丽,李春宇,余绍文,等.湿地完整性评价方法研究进展[J].安全与环境工程,2008,15(4):1-4.
[7]章光新,尹雄锐,冯夏清.湿地水文研究的若干热点问题[J].湿地科学,2008,6(2):105-115.
[8]贾志军,宋长春.湿地生态系统CO2净交换、水汽通量及二者关系浅析[J].生态与农村环境学报,2006,22(2):75-79.
[9]沈艳,刘允芬,王堰.应用涡动相关法计算水热、CO2通量的国内外进展概况[J].南京气象学院学报,2005,28(4):559-566.
[10]Allen R G,Pereira L S,Howell T A,et al.Evapotranspiration information reporting:I.Factors governing measurement accuracy[J].Agricultural Water Management,2011,98(6):899-920.
[11]Aouade G,Ezzahar J,Amenzou N,et al.Combining stable isotopes,eddy covariance system and meteorological measurements for partitioning evapotranspiration,of winter wheat,into soil evaporation and plant transpiration in a semi-arid region[J].Agricultural Water Management,2016,177(6):181-192.
[12]Baldocchi D D.Assessing the eddy covariance technique for evaluating carbon dioxide exchange rates of ecosystems:Past,present and future[J].Global Change Biology,2003,9(4):479-492.
[13]刘玉莉,江洪,陈健,等.安吉毛竹林碳水通量及水分利用效率的日动态研究[J].生态科学,2015,34(4):43-51.
[14]曹生奎,曹广超,陈克龙,等.青海湖高寒湿地生态系统CO2通量和水汽通量间的耦合关系[J].中国沙漠.2016,36(5):1286-1295.
[15]李杰,郑卓,Cheddadi R,等.神农架大九湖四万年以来的植被与气候变化[J].地理学报,2013,68(1):69-81.
[16]罗涛,伦子健,顾延生,等.神农架大九湖湿地植物群落调查与生态保护研究[J].湿地科学,2015,13(2):153-160.
[17]向兴,王红梅,龚林锋,等.细菌群落在神农架大九湖泥炭藓与表层沉积物的垂向变化及其生态意义[J].中国科学:地球科学,2014,44(6):1244-1252.
[18]Eva F,Baldocchi D D,Olson R,et al.Gap filling strategies for long term energy flux data sets[J].Agricultural and Forest Meteorology,2001,107(1):71-77.
[19]Sulman B N,Roman D T,Scanlon T M,et al.Comparing methods for partitioning a decade of carbon dioxide and water vapor fluxes in a temperate forest[J].Agricultural and Forest Meteorology,2016,226/227:229-245.
[20]Wilson K B,Hansonb P J,Baldocchi D D.Factors controlling evaporation and energy partitioning beneath a deciduous forest over an annual cycle[J].Agricultural and Forest Meteorology,2000,102(2):83-103.
[21]Soubie R,Heinesch B,Granier A,et al.Evapotranspiration assessment of a mixed temperate forest by four methods:Eddy covariance,soil water budget,analytical and model[J].Agricultural and Forest Meteorology,2016,228/229:191-204.
[22]Mitchell S R,Emanuel R E,Mcglynn B L.Land-atmosphere carbon and water flux relationships to vapor pressure deficit,soil moisture,and stream flow[J].Agricultural and Forest Meteorology,2015,208:108-117.
[23]郭瑞萍,莫兴国.森林、草地和农田典型植被蒸散量的差异[J].应用生态学报,2007,18(8):1751-1757.
[24]李菊,刘允芬,杨晓光,等.千烟洲人工林水汽通量特征及其与环境因子的关系[J].生态学报,2006,26(8):2449-2456.
[25]蔺恩杰,江洪,陈云飞.太湖源雷竹林水汽通量变化及其对净辐射的响应[J].浙江农林大学学报,2013,30(3):313-318.
[26]高升华.杨树人工林皆伐对生态系统CH4、CO2和水汽通量的影响[D].北京:中国林业科学研究院,2015.
[27]高扬子,何洪林,张黎,等.近50年中国地表净辐射的时空变化特征分析[J].地球信息科学学报,2013,15(1):1-10.
[28]牛晓栋.天目山老龄森林生态系统碳水通量及水汽稳定同位素观测[D].杭州:浙江农林大学,2015.
[29]贾志军,宋长春,王跃思,等.三江平原典型沼泽湿地蒸散量研究[J].气候与环境研究,2007,12(4):496-502.
[30]王沙生,高荣孚,吴贯明.植物生理学[M].北京:中国林业出版社,1990:202-203.
[31]于贵瑞,王秋凤,米娜.植物光合、蒸腾与水分利用的生理生态学作[M].北京:科学出版社,2010:350-360.
[32]Emanuel R E,Epstein H E,Brian L,et al.Spatial and temporal controls on watershed eco-hydrology in the northern Rocky Mountains[J].Water Resources Research,2010,46(11):2387-2392.
[33]Zhang X J,Jin C J,Guan D X,et al.Long-term eddy covariance monitoring of evapotranspiration and its environmental factors in a temperate mixed forest in Northeast China[J].Journal of Hydrologic Engineering,2012,17(9):965-974.
[2]张小斌,李新.我国水环境安全研究进展[J].安全与环境工程,2013,20(1):122-125,137.
[3]欧阳峰,陆一新,黄冬梅.水污染造成的环境经济损失分析[J].安全与环境工程.2006,13(1):33-36.
[4]刘玉莉,江洪,周国模,等.安吉毛竹林水汽通量变化特征及其与环境因子的关系[J].生态学报,2014,34(17):4900-4909.
[5]牛晓栋,江洪,方成圆,等.天目山常绿落叶阔叶混交林生态系统水汽通量特征[J].浙江农林大学学报,2016,33(2):216-224.
[6]杨丽,李春宇,余绍文,等.湿地完整性评价方法研究进展[J].安全与环境工程,2008,15(4):1-4.
[7]章光新,尹雄锐,冯夏清.湿地水文研究的若干热点问题[J].湿地科学,2008,6(2):105-115.
[8]贾志军,宋长春.湿地生态系统CO2净交换、水汽通量及二者关系浅析[J].生态与农村环境学报,2006,22(2):75-79.
[9]沈艳,刘允芬,王堰.应用涡动相关法计算水热、CO2通量的国内外进展概况[J].南京气象学院学报,2005,28(4):559-566.
[10]Allen R G,Pereira L S,Howell T A,et al.Evapotranspiration information reporting:I.Factors governing measurement accuracy[J].Agricultural Water Management,2011,98(6):899-920.
[11]Aouade G,Ezzahar J,Amenzou N,et al.Combining stable isotopes,eddy covariance system and meteorological measurements for partitioning evapotranspiration,of winter wheat,into soil evaporation and plant transpiration in a semi-arid region[J].Agricultural Water Management,2016,177(6):181-192.
[12]Baldocchi D D.Assessing the eddy covariance technique for evaluating carbon dioxide exchange rates of ecosystems:Past,present and future[J].Global Change Biology,2003,9(4):479-492.
[13]刘玉莉,江洪,陈健,等.安吉毛竹林碳水通量及水分利用效率的日动态研究[J].生态科学,2015,34(4):43-51.
[14]曹生奎,曹广超,陈克龙,等.青海湖高寒湿地生态系统CO2通量和水汽通量间的耦合关系[J].中国沙漠.2016,36(5):1286-1295.
[15]李杰,郑卓,Cheddadi R,等.神农架大九湖四万年以来的植被与气候变化[J].地理学报,2013,68(1):69-81.
[16]罗涛,伦子健,顾延生,等.神农架大九湖湿地植物群落调查与生态保护研究[J].湿地科学,2015,13(2):153-160.
[17]向兴,王红梅,龚林锋,等.细菌群落在神农架大九湖泥炭藓与表层沉积物的垂向变化及其生态意义[J].中国科学:地球科学,2014,44(6):1244-1252.
[18]Eva F,Baldocchi D D,Olson R,et al.Gap filling strategies for long term energy flux data sets[J].Agricultural and Forest Meteorology,2001,107(1):71-77.
[19]Sulman B N,Roman D T,Scanlon T M,et al.Comparing methods for partitioning a decade of carbon dioxide and water vapor fluxes in a temperate forest[J].Agricultural and Forest Meteorology,2016,226/227:229-245.
[20]Wilson K B,Hansonb P J,Baldocchi D D.Factors controlling evaporation and energy partitioning beneath a deciduous forest over an annual cycle[J].Agricultural and Forest Meteorology,2000,102(2):83-103.
[21]Soubie R,Heinesch B,Granier A,et al.Evapotranspiration assessment of a mixed temperate forest by four methods:Eddy covariance,soil water budget,analytical and model[J].Agricultural and Forest Meteorology,2016,228/229:191-204.
[22]Mitchell S R,Emanuel R E,Mcglynn B L.Land-atmosphere carbon and water flux relationships to vapor pressure deficit,soil moisture,and stream flow[J].Agricultural and Forest Meteorology,2015,208:108-117.
[23]郭瑞萍,莫兴国.森林、草地和农田典型植被蒸散量的差异[J].应用生态学报,2007,18(8):1751-1757.
[24]李菊,刘允芬,杨晓光,等.千烟洲人工林水汽通量特征及其与环境因子的关系[J].生态学报,2006,26(8):2449-2456.
[25]蔺恩杰,江洪,陈云飞.太湖源雷竹林水汽通量变化及其对净辐射的响应[J].浙江农林大学学报,2013,30(3):313-318.
[26]高升华.杨树人工林皆伐对生态系统CH4、CO2和水汽通量的影响[D].北京:中国林业科学研究院,2015.
[27]高扬子,何洪林,张黎,等.近50年中国地表净辐射的时空变化特征分析[J].地球信息科学学报,2013,15(1):1-10.
[28]牛晓栋.天目山老龄森林生态系统碳水通量及水汽稳定同位素观测[D].杭州:浙江农林大学,2015.
[29]贾志军,宋长春,王跃思,等.三江平原典型沼泽湿地蒸散量研究[J].气候与环境研究,2007,12(4):496-502.
[30]王沙生,高荣孚,吴贯明.植物生理学[M].北京:中国林业出版社,1990:202-203.
[31]于贵瑞,王秋凤,米娜.植物光合、蒸腾与水分利用的生理生态学作[M].北京:科学出版社,2010:350-360.
[32]Emanuel R E,Epstein H E,Brian L,et al.Spatial and temporal controls on watershed eco-hydrology in the northern Rocky Mountains[J].Water Resources Research,2010,46(11):2387-2392.
[33]Zhang X J,Jin C J,Guan D X,et al.Long-term eddy covariance monitoring of evapotranspiration and its environmental factors in a temperate mixed forest in Northeast China[J].Journal of Hydrologic Engineering,2012,17(9):965-974.