中文摘要：

采用室内单养和混养方法, 设置不同的氮、磷营养条件, 研究了氮、磷对中肋骨条藻（Skeletonema costatum）和锥状斯氏藻（Scrippsiella trochoidea）种间竞争的影响。结果表明： 混养时各氮和磷浓度下均呈现培养初期中肋骨条藻为优势种、培养后期锥状斯氏藻为优势种的变化趋势, 但随着氮、磷浓度的升高, 中肋骨条藻作为优势种的时间延长; 与单养时相比, 混养中两种微藻的最大密度受到不同程度的抑制, 表现出氮、磷浓度越高, 受抑制的程度越大的特征, 且与锥状斯氏藻相比, 中肋骨条藻的最大密度受到抑制的程度更大。混养时两种微藻均是在氮、磷浓度最高时, 抑制起始点出现时间最长, 随着氮、磷浓度的降低, 抑制起始点出现时间缩短; 各氮、磷浓度条件下, 锥状斯氏藻对中肋骨条藻的竞争抑制参数明显高于中肋骨条藻对锥状斯氏藻的竞争抑制参数, 当氮浓度为512 μmol·L（–1）、磷浓度为2 μmol·L（–1）时, 竞争结果是锥状斯氏藻获胜; 其余氮、磷浓度条件下为两种微藻不稳定共存。

英文摘要：

Aims Skeletonema costatum and Scrippsiella trochoidea are two algal species that can cause red tides together. Interspecific competition is thought to be a factor in development of algal blooms. Our objective is to study the effect of nitrogen and phosphorus on interspecific competition between Skeletonema costatum and Scrippsiella trochoidea. Methods The experiments were carried out in mono-culture and co-culture. The nitrogen （nitrate） and phospho- rus （phosphate） concentrations were 32, 32; 128, 32; 512, 32; 512, 8; 512, 2 μmol.L-1, respectively. Important findings With increased concentration of nitrogen and phosphorus, the time of Skeletonema costatum as the dominant species was prolonged. Compared with mono-culmre, the maximum densities of two species were inhibited in co-culture, and the degree of inhibition increased with higher concentration of nitrogen and phosphorus. The maximum density of Skeletonema costatum was more inhibited than that of Scrippsiella trochoidea. When the concentration of nitrogen and phosphorus was highest, the inhibitory starting point （tp） of the two species was highest, and with the decline of nutrients, the tp also decreased. Under various nutritional conditions, competitive inhibition parameters of Scrippsiella trochoidea to Skeletonema costatum （fl） were higher than a. Scrippsiella trochoidea out-competed Skeletonema costatum when nitrogen was 512 μmol.L-1 and phosphorus was 2 μmol.L-1. In other nutritional conditions, competition resulted in unstable coexistence of the species.