发表机构
Mathematical Institute, Leiden University; Center for Advanced Systems Understanding,(CASUS) – Helmholtz-Zentrum Dresden-Rossendorf (HZDR); ICTP South American Institute for Fundamental Research & Instituto de Física Teórica, Universidade Estadual Paulista- UNESP; Department of Ecology, Institute of Biosciences, University of São Paulo（莱顿大学数学研究所; 先进系统理解中心（CASUS）- 德累斯顿罗斯多夫亥姆霍兹中心（HZDR）; 国际理论物理研究所南美基础研究院与圣保罗州立大学理论物理研究所; 圣保罗大学生物科学学院生态学系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文研究根异速生长与根重叠对植被斑图形成的影响，发现二者通过双重积分结构驱动两种图灵不稳定性机制，且分别促进或抑制竞争压力区的形成。
AI 中文摘要
我们研究了根异速生长以及因根重叠导致的地下根竞争如何影响非局部标量植被模型中斑图形成的条件。我们从空间显式的两分量植被-水系统出发，在该系统中，植物通过其横向伸展的根系获取土壤水分，其中根异速生长由相互作用核表示，其空间范围随地上生物量密度增加而增大。在水动力学快速极限下，我们消去水分变量，得到植被动力学的非局部标量模型。这一约化过程揭示出，考虑根重叠自然会导致标量模型中产生双重积分结构，这与通常用于模拟资源非局部竞争的单一卷积项形成对比。对于所得的标量模型，我们确定了两种能够驱动图灵不稳定性的不同机制。第一种不稳定机制要求根系生长速度超过死亡率，而第二种机制依赖于竞争压力区的形成，在该区域中，植被生长受到邻近高生物量密度区域累积竞争压力的阻碍。根异速生长促进两种不稳定机制的发生，而根重叠则抑制竞争压力区的出现。因此，我们的结果表明，在研究植被斑图形成时，根异速生长和根重叠都是需要考虑的重要特征。
英文摘要
We investigate how root allometry and below-ground root competition due to root overlap affect the conditions for pattern formation in non-local scalar vegetation models. We start from a spatially explicit two-component vegetation-water system in which plants acquire soil water through their laterally extended root systems, with root allometry represented by an interaction kernel whose spatial extent increases with the above-ground biomass density. In the limit of fast water dynamics, we eliminate the water variable, resulting in a non-local scalar model for the vegetation dynamics. This reduction reveals that accounting for root overlap naturally leads to a double integral structure in the scalar model, in contrast to the single convolution term commonly used to model non-local competition for resources. For the resulting scalar model, we identify two distinct mechanisms that can drive Turing instabilities. The first instability mechanism requires root growth to outpace mortality, while the second mechanism relies on the development of competitive pressure zones, in which vegetation growth is impeded by the cumulative competitive pressure exerted by neighbouring areas with higher biomass density. Root allometry promotes the occurrence of both instability mechanisms, while root overlap inhibits the emergence of competitive pressure zones. Hence, our results show that both root allometry and root overlap are important features to consider when studying vegetation pattern formation.
Comments25 pages, 3 figures
