不同氮磷比对多年生水生植物生长特性影响的研究

Influence of different nitrogen:phosphorus on growth characteristic of perennial aquatic plant

从氮、磷等植物生长的环境因子出发,研究了高低氮磷营养水平下,不同氮/磷比例的富营养化水体对聚草(Myriophyllum spicatum)、黄花水龙(Jussiaea stipulacea Ohwi)、喜旱莲子草(Alternanthera philoxeroides)生长特性的影响。结果表明,聚草在氮磷比2∶1时生物量最大,且生物量在高浓度水平处理明显大于低浓度水平处理(P<0.01);黄花水龙在氮磷比10∶1～20∶1时生物量最大,高低浓度水平处理间生物量无显著性差异;喜旱莲子草在较高氮磷比20∶1～40∶1时生物量最大,高浓度水平处理时生物量显著性高于低浓度水平处理(P<0.05)。在低浓度水平处理时,氮为黄花水龙和喜旱莲子草生长的主要限制因子,磷为聚草生长的主要限制因子,且喜旱莲子草叶绿素增长期较其他处理提前,而黄花水龙的叶绿素变化在高低营养水平下差异不显著。营养盐水平对聚草茎长和生物量的影响较对黄花水龙和喜旱莲子草的影响明显。

The growth characteristics of Myriophyllum spicatum, Jussiaea stipulacea Ohwi, Alternanthera philoxeroides were studied in different N： P ratios at different nutritional levels. The result indicated that M. spicatum had the maximum biomass at the ratio of 2： l, and the biomass was higher at higher ratio than at lower ratio of2：1 （P 〈0.01）. J. stipulaceai showed biomass peaks at the ratio of 10：1 and 20：1, no significant difference between biomass at higher level and lower level was present. A. philoxeroides had the highest biomass at 20 ： 1 and 40： 1, there was significant difference in biomass between higher ratio and lower ratio （P 〈 0.05）. At low level, nitrogen was the limiting factor for J. stipulacea and A. philoxeroides, while phosphorus was the limiting factor for M. spicatum. Increase of Chl a content in A. philoxeroides was found at low N and P treatment. Chla content of J. stipulacea did not vary significantly between high and low N and P level treatments. The nutritional level stimulated stem growth of M. spicatum more than J. stipulacea and A. philoxeroides.