A porous convection model for small-scale grass patterns

Spatial ecological patterns are usually ascribed to Turing‐type reaction‐diffusion or scale‐dependent feedback processes, but morphologically indistinguishable patterns can be produced by instabilities in fluid flow. We present a new hypothesis that suggests that fluid convection and chill damage to plants could form vegetation patterns with wavelengths ≈1–2 times the plant height. Previous hypotheses for small‐scale vegetation pattern formation relied on a Turing process driven by competition for water, which is thought to occur in large vegetation patterns. Predictions of the new hypothesis were consistent with properties of natural grass patterns in North Carolina, contradicting the Turing hypothesis. These results indicate that similarities in pattern morphology should not be interpreted as implying similarities in the pattern‐forming processes, that small‐wavelength vegetation patterns may arise from mechanisms that are distinct from those generating long‐wavelength vegetation patt...空间生态格局通常被归因于图灵型反应扩散（Turing-type reaction-diffusion）或尺度依赖反馈过程，但形态上难以区分的格局亦可由流体流动的不稳定性催生。本研究提出一项全新假说，认为流体对流与植物冷害（chill damage）可形成波长约为植株高度1~2倍的植被格局。此前针对小型植被格局形成的相关假说均依赖于由水分竞争驱动的图灵过程，而该过程被认为是大型植被格局的形成机制。新假说的预测结果与北卡罗来纳州（North Carolina）天然草地格局的特征相符，却与图灵假说相悖。上述研究结果表明，不应仅凭格局形态的相似性就推断其形成过程的一致性；小波长植被格局的成因或许与长波长植被格局的形成机制截然不同。