Petersen J E, Hastings A
Lewis Center for Environmental Studies, Oberlin College, Oberlin, Ohio 44074, USA.
Am Nat. 2001 Mar;157(3):324-33. doi: 10.1086/319197.
Enclosed experimental ecosystems (mesocosms) are small relative to their natural counterparts, are typically operated for short durations relative to the timescales of a number of important ecological processes, and also often have reduced biological and physical complexity relative to nature. These reductions in time, space, and complexity scales have been cited as sources of unrealistic ecological behavior within mesocosms and raise questions about extrapolating results from mesocosms to nature. Dimensional analysis, a technique widely used by engineers to create scale models, uses compensatory distortion as a means of maintaining dynamic similarity in properties and relationships of interest. Although biological parameters are generally less controllable than physical ones, a variety of dimensional approaches can be taken to maintain such key ecological properties as effective habitat size, environmental variability, vertical and horizontal gradients, interactions among habitats, and control of experimental artifacts. To date, application of dimensional approaches to mesocosm design has been largely intuitive and idiosyncratic. We argue that a more explicit, systematic, and quantitative approach will increase realism and may also provide a critical means of developing, testing, and advancing our understanding of scaling relationships in nature.
封闭式实验生态系统（中宇宙）相对于自然生态系统而言规模较小，相对于许多重要生态过程的时间尺度来说，其运行时间通常较短，而且相对于自然环境，其生物和物理复杂性也常常有所降低。时间、空间和复杂性尺度的这些缩减被认为是中宇宙内出现不切实际生态行为的原因，并引发了关于将中宇宙的结果外推至自然环境的质疑。量纲分析是工程师广泛用于创建比例模型的一种技术，它利用补偿失真作为在感兴趣的属性和关系中保持动态相似性的手段。尽管生物参数通常比物理参数更难控制，但可以采用多种量纲方法来维持诸如有效栖息地大小、环境变异性、垂直和水平梯度、栖息地间相互作用以及对实验假象的控制等关键生态属性。迄今为止，量纲方法在中宇宙设计中的应用很大程度上是直观且独特的。我们认为，一种更明确、系统和定量的方法将提高现实性，还可能为发展、检验和推进我们对自然尺度关系的理解提供关键手段。
