营养盐对中肋骨条藻和新月菱形藻生长及氮磷组成的影响

EFFECTS OF NUTRIENTS ON THE GROWTH AND THE COMPOSITION OF MTROGEN AND PHOSPHORUS OF SKELETONEMA COSTATUM AND MITZSCHIA CLOSTERIUM

：于１９９５年５月１９９６年３月通过一次培养实验，研究了培养介质中营养盐含量变化对中肋骨条藻和新月菱形藻生长速率和藻体氮、磷含量的影响。根据Ｍｏｎｏｄ方程，磷酸盐影响中肋骨条藻和新月菱形藻生长速率的半饱和常数分别为０．５４μｍｏｌ／Ｌ和０．５０μｍｏｌ／Ｌ；硝酸盐影响两种藻生长速率的半饱和常数分别为４．０μｍｏｌ／Ｌ和１４．６μｍｏｌ／Ｌ，相比之下新月菱形藻更容易受到氮不足的限制。将Ｍｏｎｏｄ方程扩展得到营养限制复合模式，限制程度可用限制作用系数定量化表示，代表氮或磷。培养介质中营养盐浓度是限制浮游植物生长的决定因素，其Ｎ／Ｐ比值则反映ＮＯ_３－Ｎ和ＰＯ_４－Ｐ何者起主要限制作用。藻体氮、磷含量随和有明显变化。当＜０．８０时较低，磷含量因贮存而明显升高；当＜０．８０时藻体磷含量下降，氮含量略有增加。藻体氮含量或＞０．８０时基本上为非限制状态。

The effects of nutrients on the growth rates and the cell composition of nitrogen and phosphorus of Skeletonema costatum and Nitzschia closterium were studied in June 1995 to Mar 1996 by batch culture. The effects of nitrate and phosphate concentration of the culture medium on the algal growth rates of the two species in batch culture can be described using the Monod equation. The halfsaturation constants for the growth of Skeletonema costatum and Nitzschia closterium influenced by nitrate (K) are 0.54 and 0.50μmol /L, respechvely. Those for the growth of the two species influenced by phosphate (Kμ(P)) are 4.0 and 14.6μmol /L respectively. Nitzschia closterium is easily limited by nitrogen shortcoming compared with Skeletonema costatum. The multi-limitation model can be arrived by expanding the Monod equation. The degree of the nutrient limitation can be expressed using the limitation effecting coefficient represents nitrogen or phosphorus). It can be found from the multi-limitation model that the nutrient concentrations of the culture medium is the dominating limit factor of the growth rate of phytoplankton. The growth rate of phytoplankton will be mainly limited by nitrogen when CN/Cp> K/K, and it will be limited mainly by phosphorus when CN/CP