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作 者 ：郭继勋, 仲伟彦

期 刊 ：植物生态学报 1994年 18卷 1期 页码：17-22

关键词：氮；磷；钾；营养元素动态；

Keywords:Nitrogen, Phosphorus, Potassium, Nutrient dynamics,

摘 要 ：羊草草原土壤中N、P、K含量的季节变化规律是生长季初期较高，6—8月生长旺季较低，生长季末再度升高。营养元素在植物体内的分配是地下部分大于地上部分。地下部分N的贮量为地上部分的3.6倍，K为2.9倍，P为2.8倍。地上部分3种元素含量的季节变化曲线呈单峰型，从生长初期开始上升，最大值出现在8月，生长末期逐渐下降。地下部分的季节变化规律，大体上在整个生长季内呈上升趋势，随着根系的生长，营养元素的积累量不断增加。对植物—土壤之间营养元素动态分析结果表明，随着时间的推移，N、P、K在各状态中的比例趋于恒定。在稳定状态下，3种元素在土壤中的比例逐渐减少，与初始量相比N、P、K的含量分别减少21.23%、5.14%和2.99%。在其它状态中，3种元素的含量均有提高，特别在枯枝落叶和死根中增加的幅度较大。

Abstract:The seasonal changes of N, P and K contents in the soil of an Aneurolepidium chinensis grassland were relatively high in the initial growth stage, relatively low in the peak growth stage from June to August and went up again at the end of the growth season.The N, P and K concentrations in the aboveground tissues were 3.6, 2.9 and 2.8 times, respectively, of those in the below ground. The seasonal changes of these three elements assumed a singlepeaked curve. They gradually increased at the initial growth stage, maximized in August, and then gradually declined. The concentrations of the three elements tended to increase during the growth season, and an apparent gradual accumulation of them in the growing roots was found.An analysis of the seasonal dynamics of N, P and K in the plant-soil system revealed that the proportions of them in different compartments tended to reach a constant with time. In the steady state, the N, P and K contents decreased 21.23, 5.14 and 2.99%, respectively, in comparison with the initial concentrations. In other states, the N, P and K concentrations tended to increase in all the compartments, especially in the litter and roots, which suggested that litter and dead roots are the major nutrient storage pools.

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