不同水分梯度下小叶章地上构件C,N,P含量动态分析

通过野外调查分析,研究了波动水文情势下,不同水分梯度带小叶章地上构件C,N,P含量动态。结果表明,各构件TC含量随时间波动变化,常年积水带大于无常年积水带;TN和TP含量,总体随水分的增加而减小,且生长季内含量逐渐下降;3种元素含量总体均为叶片含量高于茎和鞘。构件C/N常年积水和无常年积水两种情况下随水分增加呈现不同变化规律;C/P随水分的增加及生长过程的推进而增大;N/P总体随水分的增加而增大,生长季内均呈先增加后减小的波动变化。随水分的增加,小叶章质量下降;生长季初期,各水分梯度带小叶章生长均受N限制,而后期无常年积水区生长受N限制,深度积水区则受P限制。

C,N,and P Dynamics in Above-Ground Parts of Calamogrostis Angustifola Under Different Water Conditions

C,N and P dynamics in above ground parts of Calamogrostis angustifola,which was growing on different water zones with various water regimes,were studied by field investigation.The results show that total carbon(TC) fluctuated with time in all zones and were higher in the zones inundated all year long.Total nitrogen(TN) and total phosphorus(TP) decreased with time and the increase of soil water.C,N,and P of the leaves were higher than that of stems and vaginas.The ratio of C and N differed in zones with various inundation periods,and the ratio of C and P increased with the growth of the plant and soil water contents.The ratio of N and P generally increased with soil water contents,while increased and then decreased in the growing season.The quality of Calamogrostis angustifola decreased with increasing soil water.At the early growing stage,the growth of the plant was limited by N under all water conditions,while at the later growing stage,P was the limiting factor at the zone inundated all year long and N remained the stressing factor in the other zones.