Koszalka I, Bracco A, Pasquero C, Provenzale A
Doctorate Program in Fluid Dynamics, Politecnico di Torino, Italy.
Theor Popul Biol. 2007 Aug;72(1):1-6. doi: 10.1016/j.tpb.2007.03.007. Epub 2007 Mar 24.
Mathematical models used to represent plankton dynamics often display limit-cycle behavior in a range of realistic parameter values. However, experimental data do not show evidence of plankton oscillations besides externally driven seasonal blooms, casting doubts on the validity of the models themselves. In this work we show that spatial-temporal variability, coupled with advection by mesoscale turbulence, can disguise limit-cycle behavior to the point that it cannot be detected in fixed-point measurements of plankton abundance. The results presented here have more general implications as they indicate that the behavior of ecosystem models in the presence of advection can be very different from that occurring for homogeneous conditions. Care should thus be exercised in drawing general conclusions from the analysis of homogeneous ecosystem models.
用于描述浮游生物动态的数学模型在一系列现实参数值范围内常常表现出极限环行为。然而，除了外部驱动的季节性水华外，实验数据并未显示出浮游生物振荡的证据，这使得人们对模型本身的有效性产生怀疑。在这项研究中，我们表明时空变异性，再加上中尺度湍流的平流作用，能够掩盖极限环行为，以至于在浮游生物丰度的定点测量中无法检测到。这里呈现的结果具有更广泛的意义，因为它们表明在存在平流的情况下生态系统模型的行为可能与均匀条件下的行为有很大不同。因此，在从均匀生态系统模型的分析中得出一般性结论时应谨慎行事。
