Abstract:

Short-term batch cultures were used to measure the phosphate-dependent growth kinetics for a marine microalga, Tetraselmis subcordiformis (Wille) Hazen, and a marine macroalga, Ulva pertusa Kjellm. Results were fitted to the Monod model. U. pertusa had a lower half-saturation constant and maximum growth rate, which were 0.016 μmol/L and 0.16 d-1respectively，while the growth kinetics of T. subcordiformis were 0.021μmol/L and 0.83 d-1.Long-term semicontinuous nutrient competition experiments were performed between T. subcordiformis and U. pertusaunder phosphate limitation in laboratory. Loss rates were manipulated to get the same or different resource requirement values (R*) of the two species. Comparison between the theoretical predictions derived from Monod kinetics and the outcome of competition experiments indicated that the Monod model could predict the results only when the R* values of the two species were significantly different, and T. subcordiformis displaced U. pertusa when they had the same resource requirements. The Monod model can only partly predict th competition results between microalga and macroalga. Key words: macroalga; microalga; Monod model; phosphate; resource competition theory; R*-rule

磷限制下大型海藻与微藻间资源竞争理论的实验验证
南春容 双 林 金 秋

（1. 汕头大学海洋生物广东省重点实验室，汕头515063；
2. 青岛海洋大学教育部水产养殖重点实验室，青岛266003）

摘要： 用一次性培养法结合Monod方程测得海洋微藻-亚心型扁藻(Tetraselmis subcordiformis (Wile) Hazen)与大型海藻-孔石莼(Ulva pertusa Kjellm.)磷限制下的生长动力参数.孔石莼具有较低的半饱和生长常数及最大生长率,其分别为0.016 μmol/L和0.16 d-¹,而亚心型扁藻的半饱和生长常数和最大生长率分别是0.021 μmol/L 和0.83 d-¹. 两种藻类间的营养竞争实验采用半连续培养法在磷限制条件下进行,实验过程中,分别对两者施予相同或不同的去除率,使两者享有相同或不同的资源需求值R*.由Monod方程所作的竞争预测与实验观察结果的比较显示:仅在两种藻类间的资源需求值R*差异显著(t检验,P＜0.01)时,Monod方程才能对竞争结果作出较为准确的预测;在两种藻类享有相同的资源需求值R*时,亚心型扁藻在竞争中取代孔石莼.Monod模型仅能部分预测大型海藻与海洋微藻间的竞争结果.

关键词： 大藻；微藻；Monod方程；磷；资源竞争理论；R*-法则

通讯作者。E-mail:nanchunrong @ eyou .com。