水文过程对缙云山径流盐基离子变化特征的影响

Influence of hydrological processes on the runoff variation of base cations in Jinyun Mountain

通过选取缙云山针阔混交林(马尾松×四川大头茶)和常绿阔叶林(四川大头茶×四川山矾)内2个标准径流小区,结合野外观测和室内分析研究降雨及径流的化学性质径流盐基离子变化特征,为该地区水环境保护提供依据。结果表明:1)针阔混交林与常绿阔叶林中p H值变化趋势相同均为:地表径流>壤中流>大气降水。p H与降雨量之间存在显著相关关系。2)在大气降雨-地表径流-壤中流过程中,NH+4的地表径流及壤中流输出总量小于降雨输入量,表明了土壤对NH+4有一定的吸附持留能力。其他盐基离子径流输出量均高于大气降雨的输入量,且主要以壤中流输出为主,元素发生流失。从盐基离子总量来看,径流输出量均增加:针阔混交林(2.86 kg/hm2),常绿阔叶林(2.47 kg/hm2),说明在两种林分内养分均流失。(3)K+、Ca2+、Mg2+和Na+盐基离子输出量与径流量之间存在相关关系,随着径流量的增大径流输出量增加。而NH+4输出量与径流量之间的相关性不明显,说明了NH+4的变化除受径流量的影响外,可能还受微生物、季节等其他因素的影响。

By selected two standard runoff plots of Mixed conifer( Pinus massoniana × Gordonia acuminata) and Evergreen broad-leaved forest( Gordonia acuminata × Symplocos setchuanensis) in Jinyun Mountain,combined with field observations and laboratory analysis of rainfall and runoff chemical properties,conducts a study about the runoff variation of base cations in the hydrological process to provide a basis for the protection of the water environment in this region. The results show that:( 1) p H value in Mixed coniferous and evergreen broad-leaved forest have the same trends: surface runoff > interflow>precipitation. There is significant correlation between p H and rainfall.( 2) In rainfall-surface runoff-interflow process,the sum of NH+4surface runoff output and interflow output is less than the amount of rainfall input,indicating that the soil have a certain of retain the ability of NH+4to make it loss less. While the runoff outputs of other base cations are higher than rainfall input and element loss,respectively. In terms of the total amount of base cations,compared to the rainfall the runoff output of base cations increased: mixed coniferous( 2.86 kg / hm2),evergreen broad-leaved forest( 2.47 kg/hm2),which indicates that there is a loss of base cations in the evergreen broad-leaved forest and the mixed coniferous.( 3) It has correlation between the runoff output of base cations( K+,Ca2+,Mg2+and Na+) and the amount of runoff,respectively,which mean the output of cations rise with the increase of runoff. While that of NH+4has no obvious correlation between the output runoff. In addition to the impact of runoff,the changes of NH+4may also be affected by other factors such as micro-organisms,season and so on.