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盐胁迫明显抑制杨树幼苗高生长，其高生长速率随胁迫时间的延长和盐浓度的增加而减小，与此同时，叶片中Ｃｌ￣－、Ｎａ￣＋的累积则增加，叶片中游离脯氨酸的累积在胁迫后约２～３ｄ达到峰值，Ｋ￣＋累积则在胁迫后约２周迅速增加，两者都是在峰值之后随胁迫时间的延长而下降。杨树幼苗对Ｃｉ￣－和Ｎａ￣＋的吸收并不同步，胁迫后期Ｎａ￣＋／Ｃｌ￣－的值逐渐升高，在浓度为０．３％的处理组比值可达１．５．同时，Ｎａ￣＋／Ｋ￣＋值的升高是Ｎａ￣＋吸收增加而Ｋ￣＋吸收减少的结果。外源Ｋ￣＋、Ｃａ￣２＋对盐胁迫抑制高生长有一定的缓解作用，但Ｋ＋的作用不及Ｃａ２＋。
Salt stress significantly inhibited the high growth of poplar seedlings, and its high growth rate decreased with the prolongation of salt stress and salt concentration. At the same time, the accumulation of Cl ~ - and Na ~ + in leaves increased, The accumulation of amino acid peaked at about 2 ~ 3d after stress, while the accumulation of K ~ + increased rapidly at about 2 weeks after stress, both of which decreased with the prolongation of stress time after the peak. Poplar seedlings did not synchronize the uptake of Ci ~ - and Na ~ +, and the Na ~ + / Cl ~ - values gradually increased in the later stage of stress, up to 1.5 in the 0.3% treatment group. Meanwhile, the increase of Na ~ + / K ~ + value is the result of Na ~ + absorption increase and K ~ + absorption decrease. Exogenous K ~ +, Ca ~ 2 + can restrain high growth by salt stress, but K + is less effective than Ca2 +.