Zhang Bo, Liu Xin, DeAngelis D L, Ni Wei-Ming, Wang G Geoff
Department of Biology, University of Miami, Coral Gables, FL 33124, USA.
Nanjing Forestry University, 210037 Nanjing, China.
Math Biosci. 2015 Jun;264:54-62. doi: 10.1016/j.mbs.2015.03.005. Epub 2015 Mar 27.
An intriguing recent result from mathematics is that a population diffusing at an intermediate rate in an environment in which resources vary spatially will reach a higher total equilibrium biomass than the population in an environment in which the same total resources are distributed homogeneously. We extended the current mathematical theory to apply to logistic growth and also showed that the result applies to patchy systems with dispersal among patches, both for continuous and discrete time. This allowed us to make specific predictions, through simulations, concerning the biomass dynamics, which were verified by a laboratory experiment. The experiment was a study of biomass growth of duckweed (Lemna minor Linn.), where the resources (nutrients added to water) were distributed homogeneously among a discrete series of water-filled containers in one treatment, and distributed heterogeneously in another treatment. The experimental results showed that total biomass peaked at an intermediate, relatively low, diffusion rate, higher than the total carrying capacity of the system and agreeing with the simulation model. The implications of the experiment to dynamics of source, sink, and pseudo-sink dynamics are discussed.
数学领域最近一个有趣的结果是，在资源空间分布不均的环境中以中等速率扩散的种群，其总平衡生物量将高于在相同总资源均匀分布的环境中的种群。我们扩展了当前的数学理论以适用于逻辑斯谛增长，并表明该结果适用于斑块间有扩散的斑块系统，无论是连续时间还是离散时间。这使我们能够通过模拟对生物量动态做出具体预测，这些预测通过实验室实验得到了验证。该实验是对浮萍（Lemna minor Linn.）生物量增长的研究，在一种处理中，资源（添加到水中的养分）在一系列离散的盛水容器中均匀分布，而在另一种处理中则不均匀分布。实验结果表明，总生物量在中等、相对较低的扩散速率下达到峰值，高于系统的总承载能力，这与模拟模型一致。文中讨论了该实验对源、汇和伪汇动态的影响。
