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在备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。
The seasonal changes of N,Pand K contents in the soil of an Aneuro-lepidium 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 cha-nges of these three elements assumed a singlepeaked curve,They gradually increased at the initial growth stage, maximized in August,and then gradu-ally declined.The concentrations of the three elements tended to increase during the rowth season,and an apparent gradual accumulation of them in the growii1g roots was found.An analysis of the seasonal dynamics of N, P and K in the plant-soil system reyealed 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 in-crease in all the compartments,especially in the litter and roots, which sug-gested that litter and dead roots are the major nutrient storage pools。
出处
《植物生态学报》
CAS
CSCD
北大核心
1994年第1期17-22,共6页
Chinese Journal of Plant Ecology
关键词
羊草
营养元素
土壤
草原生态学
Nitrogen
Phosphorus
Potassium
Nutrient dynamics
