淀山湖浮游植物营养限制因子的研究

通过藻类增长的生物学评价(Nutrient Enrichment Bioassay)研究淀山湖浮游植物生长限制性因子，并采用析因方差分析和事后比较方法分析营养盐（PO^3-₄P、NH₃N、NO^-₃N）对浮游植物生长速度、平均最大现存量和平均最大特定增长率的影响。研究表明：磷对浮游植物生长有明显的促进作用，能提高浮游植物的生长速度和现存量，且促进作用随磷浓度（0.13～0.53 mg/L）的增加而加强，磷是淀山湖浮游植物增长的第一限制性因子；低浓度硝氮（2.91～5.91 mg/L）对浮游植物生长有微小的促进作用，但高浓度（5.91～8.91 mg/L）的硝氮表现出抑制作用；氨氮对浮游植物生长有抑制作用，并随浓度（1.25～7.25 mg/L）的增加而增大；添加磷+硝氮能明显促进浮游植物生长，磷与硝氮之间存在一定的交互作用.

NUTRIENT LIMITATION OF PHYTOPLANKTON IN DIANSHAN LAKE

This paper studied the restrictive factors which affect the growth of phytoplankton in Dianshan Lake through the Nutrient Enrichment Bioassay,combining by two analysis methods including factorial analysis of variance and post comparison analysis.The growth rate and the maximum average stock as well as the maximum average growth rate were affected by the nutrients including PO^3-₄P、NH³N、NO^-₃N.The results show that the concentration of PO^3-₄P could promote the growth of algae and increase the growth rate and standing stock.With the increase of PO^3-₄P concentration(0.13 ~0.53 mg/L),the promotion could be enhanced,PO^3-₄Pwas regarded as the first restrictive factors in Dianshan Lake;The promotion to algae of NO^-₃N in low concentration(291~591 mg/L) was small,while inhibition effects could be displayed in higher concentration(5.91~8.91 mg/L)；NO^-₃N could inhibit the growth of algae and the inhibition effect is enhanced with the increase of concentration(1.25~7.25 mg/L).In addition,the combination of PO^3-₄P and NO_^-3N could promote the growth of algae significantly,suggesting that the interaction effect exists between PO^3-₄P and NO^-₃N.