研究人员通过比较多种替代机制，发现高原土壤中的规则铁条带可以通过耦合两组尺度相关的反馈来解释，即图灵形态发生的一般原理。首先，粘土在铁氧化还原波动中的分散和凝固将土壤铁(III)聚集和晶体生长放大到对根生长产生负面影响的水平。其次，这种对高结晶铁(III)的负根反应的激活导致规则铁条带的形成。在形成铁带的过程中，环境变化起着关键作用。
它为所需的模式形成过程中、在明显分开的时间内发生创造交替的缺氧和缺氧条件，并确定缺氧和缺氧事件的持续时间，从而控制伴随氧化和还原反应的过程的相对速率。由于图灵形态发生需要特定过程速率的比率在特定范围内，因此，环境的可变性改变了模式形成发生的可能性。预估的气候变化可以显著改变许多空间自组织系统，以及与它们所呈现的显著模式相关的生态功能。这种模式形成的时间维度值得在未来密切关注。
据了解，这项研究调查了在高原土壤中产生规则间隔的富铁带的机制。这些显著的特征出现在世界各地的土壤中，但除了与氧化还原变化的普遍关联之外，它们的起源尚未得到解释。受降雨、地下水变化或灌溉的影响，高原土壤表现出显著的氧化还原波动。这种系统中的模式形成提供了一个研究空间自组织的时间方面的机会，迄今为止这方面的研究还不够。
附：英文原文
Title: The primacy of temporal dynamics in driving spatial self-organization of soil iron redox patterns
Author: Dong, Xiaoli, Richter, Daniel D., Thompson, Aaron, Wang, Junna
Issue&Volume: 2023-12-14
Abstract: This study investigates mechanisms that generate regularly spaced iron-rich bands in upland soils. These striking features appear in soils worldwide, but beyond a generalized association with changing redox, their genesis is yet to be explained. Upland soils exhibit significant redox fluctuations driven by rainfall, groundwater changes, or irrigation. Pattern formation in such systems provides an opportunity to investigate the temporal aspects of spatial self-organization, which have been heretofore understudied. By comparing multiple alternative mechanisms, we found that regular iron banding in upland soils is explained by coupling two sets of scale-dependent feedbacks, the general principle of Turing morphogenesis. First, clay dispersion and coagulation in iron redox fluctuations amplify soil Fe(III) aggregation and crystal growth to a level that negatively affects root growth. Second, the activation of this negative root response to highly crystalline Fe(III) leads to the formation of rhythmic iron bands. In forming iron bands, environmental variability plays a critical role. It creates alternating anoxic and oxic conditions for required pattern-forming processes to occur in distinctly separated times and determines durations of anoxic and oxic episodes, thereby controlling relative rates of processes accompanying oxidation and reduction reactions. As Turing morphogenesis requires ratios of certain process rates to be within a specific range, environmental variability thus modifies the likelihood that pattern formation will occur. Projected changes of climatic regime could significantly alter many spatially self-organized systems, as well as the ecological functioning associated with the striking patterns they present. This temporal dimension of pattern formation merits close attention in the future.
DOI: 10.1073/pnas.2313487120
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2313487120