应用生态学报2017，Vol.28Issue(7)：2171-2178,8.DOI:10.13287/j.1001-9332.201707.018
北京土石山区水分在土壤-植物-大气连续体(SPAC)中的稳定同位素特征
Stable hydrogen and oxygen isotope compositions in soil-plant-atmosphere continuum (SPAC) in rocky mountain area of Beijing, China
摘要
Abstract
The stable hydrogen and oxygen isotopes are environmental isotopes,which widely exist in various kinds of water.Their relative abundance variation in water can indicate the water circulation and mechanism of water use in plant.This research selected two major kinds of greening tree species,evergreen coniferous Platycladus orientalis and deciduous broad-leaved Quercus variabilis,in Beijing mountainous area,and the water movement process in soil-plant-atmosphere continuum was investigated by the variation characteristics analysis of stable hydrogen and oxygen isotope compositions in precipitation,soil water,groundwater,plant stem water and leaf water.The results showed that the meteoric water line equation of the study area was δδD =7.17δδTM O + 1.45 (R2 =0.93),and the soil evaporation line equation was δδD =3.85δδ1s O+ 1.45 (R2 =0.76).A certain degree of evaporation fractionation existed in the processes of rainfall infiltration into soil water.In different seasons,the δD and δ18O values of precipitation,soil water and spring water had different variation regularity.In rainy season,the mean δD and δ18O values were in order of precipitation＞ spring water＞soil water,with the precipitation and soil water supplied spring water together;in dry season,the order was precipitation ＞ soil water ＞ spring water,and the precipitation and spring water both contributed to soil water.The δD and δ18O fitting line equations of stem water of P.orientalis and Q.variabilis were respectively δD=5.03δ18O-30.78 and δD=3.0δ18O-48.92.The uptake water of Q.variabilis was more enriched than that of P.orientalis,and the depth of Q.variabilis water uptake in soil profile was shallower than P.orientalis.The leaf water isotopic variation of Q.variabilis was more sensitive to atmospheric environment,with the kinetic isotopic fractionation of Q.variabilis being more enriched than that of P.orientalis,but they had the same response to variation of environmental condition.关键词
水分循环/同位素/侧柏/栓皮栎/北京土石山区Key words
water cycle/isotope/Platycladus orientalis/Quercus variabilis/rocky mountain area of Beijing引用本文复制引用
邓文平,章洁,张志坚,胡少昌,郭锦荣,刘苑秋,孔凡前,张毅..北京土石山区水分在土壤-植物-大气连续体(SPAC)中的稳定同位素特征[J].应用生态学报,2017,28(7):2171-2178,8.基金项目
本文由江西省赣鄱英才555工程项目(9033204464)资助 This work was supported by the Leader Talent Cultivation Plan of Jiangxi Province "555" Project (9033204464). （9033204464）
