浮萍和水花生降盐碱的效果及其对水质的影响

于1998年7－8月间选取山东省高青县赵店乡大芦湖养殖内一口盐碱池塘的池水为试验用水，引进浮萍与水花生研究其降盐降碱作用以及它们对化学、生物因子的影响。结果表明：水花生没有明显的降盐碱作用；浮萍的降盐效果也不明显，但其降碱效果明显。同时会引起水体中中钙离子浓度下降和pH值的升高。另外，它们降低了水体中营养盐浓度和浮游植物生物量，但对浮游生物的多样性影响不大。

PERFORMANCE OF SPIODELA POLYRHIZA AND AL TERNANTHERA PHILOXER DES IN REDUCING SALINITY AND ALKALINITY AND THEIR EFFECTS ON WATER QUALITY

The experiment was conducted in Daluhu aquaculture site, Gaoqing County, Shandon g Province during August and December, 1998. It was aimed at study on the effect s of applications of aquatic plant Spiodela polyrhiza and Alternanthera philoxer oides on the chemical and hydrobiological factors in brackish-water ponds. Spiod ela polyrhiza and Alternanthera philoxeroides's performance in reducing salinity and alkalinity had also been studied. The results show that Alternanthera philo xeroides had no significant effect on reducing salinity and alkalinity. Spiodela polyrhiza also had no significant effect on reducing salinity, but it was evide nt that Spiodela polyrhiza could reduce alkalinity, lead to increasing pH values and reducing Calcium concentrations. In addition, they were able to reduce the concentrations of nutrients and phytoplankton biomass, but their effects on zoop iankton had not been observed.