不同林龄白桦次生林降雨水化学特征研究

通过对不同林龄白桦次生林林外降雨、穿透雨、树干茎流和枯透水中的Cl~-,NO_3~-N,Na~+,K~+,Ca2-,Mg~(2+)等进行测定,以研究4个林龄之间降水化学性质的差异.结果表明:林外降雨中Ca~(2+)的含量最高,Na~+含量最低,养分元素平均含量(以mg/L计)排列顺序为:Ca~(2+)>Cl~->K~+>NO_3~--N>Mg~(2+)>Na~+,各元素在林外降雨中的季节变化较大.变化幅度最小的是Cl~-;穿透雨中NO_3~--N,Ca~(2+)含量在25 a白桦次生林中最低,Cl~-,Mg~(2+)含量在38 a中最低,而Na~+,K~+含量在56 a中最低;树干茎流中Cl~-,NO_3~--N,K~+含量在38 a白桦次生林中最低,而Na~+,Ca~(2+),Mg~(2+)含量在56 a中最低;枯透水中Cl~-,NO_3~--N,Na~+,K~+含量在25 a白桦次生林中最低,Mg~(2+)含量在38 a中最低,而Ca~(2+)含量在56 a中最低.

Study on Precipitation Hydro-chemical Characteristic of Different Stages of Betula platyphylla Secondary Forest

This paper measured the precipitation, throughfall, stemflow and litter water in the Cl~- ,NH_4~+-N, Na~+ , NO_3~--N, TN, K~+ , Ca~(2+) ,Mg~(2+) of different stages of Betula platyphylla secondary forest . The paper studied the different properties of hydro-chemical between four different stages of Betula platyphylla secondary forest. The results showed: In precipitation the highest concentration was for Ca~(2+) and the lowest concentration was for Na~+. The average concentration of elements(in mg/L total) for the order Ca~(2+)>C1~-> K~+>N0_3~- —N>Mg~(2+)> Na~+ , the amount of each element was very various in terms of seasons alternate and in which the change of Cl~- was the smallest. NO_3~- - N and Ca~(2+) of throughfall was the lowest content in 25 year-old of Betula platyphylla secondary forest, Cl~- and Mg~(2+)of throughfall was the lowest concentration in38 year-old of Betula platyphylla secondary forest,Na~+ ,K~+ , Mg~(2+) of throughfall was the lowest concentration in 56 year-old of Betula platyphylla secondary forest. Cl~-, NO_3~--N, K~+ of stemflow was the lowest concentration in 38 year-old of Betula platyphylla secondary forest, Na~+ , Ca~(2+) and Mg~(2+) of stemflow was the lowest concentration in 56 year-old of Betula platyphylla secondary forest. Cl~- , NH_4~- -N, Na~+and K~+ of litter wate was the lowest concentration in 25 year-old of Betula platyphylla secondary forest,Mg~(2+) , Mn of litter wate was the lowest concentration in 38 year-old of Betula platyphylla secondary forest. Ca~(2+) of litter water was the lowest concentration in 56 year-old of Betula platyphylla secondary forest.