不同磷浓度及脉冲方式下孔石莼与亚心形扁藻间竞争的实验研究

Competition Between Platymonas subcordiformis and Ulva pertusaUnder Various Phosphorus Concentrations and Pulses

用 1次性培养法结合 Monod模型测定了大型海藻 -孔石莼和海洋微藻 ,-亚心形扁藻磷限制下的生长动力参数 ,并在相同实验条件下观察 2种藻类对不同磷浓度及脉冲方式的反应及竞争特征。结果显示 :亚心形扁藻的种群密度随着磷脉冲的增大而增加 ;孔石莼在不同磷脉冲供给的培养系统中 ,保持基本稳定的生物量。在低磷浓度 (0 .1 6μmol/ L/ d)下 ,孔石莼成为优势种群 ;在磷浓度较高的情况下 (0 .8μmol/ L/ d以上 ) ,亚心形扁藻成为优势种群。亚心形扁藻为 r-选择者 ,孔石莼为 K-选择者。

Short-term batch cultures were used to measure the phosphate-dependent growth kinetics for a marine micro-alga, Platymonas subcordiformis (Wille) Hazen, and a marine macro-alga, Ulva pertusa. Mono-culture and co-culture (competition) experiments were performed between the two species. The results indicated that Platymonas subcordiformis was r-selected while Ulva pertusa was K-selected. Platymonas subcordiformis responded to increased phosphorous pulses and dominated at high phosphorous availability (above 0.8 μmol/ L/ d); Ulva pertusa remained remarkably stable populations in various pulsed cultures and dominated at low phosphorous availability (0.16 μmol/ L/ d).