Adopting mangrove vegetation zonation patterns to gain information on subsurface aquifer structures and advance belowground plant competition concepts in individual-based modelling – MARZIPAN

通过这项拟议的项目，我们打算通过开发和采用一种新的、完全耦合的红树林生态系统植物-土壤水模型方法，来扩展对植被和地下水动力学之间相互作用的知识和过程的理解。具体地说，我们想深入了解(I)可见的植被模式之间的关系，如异速生长、物种组成和分区，以及(Ii)地下含水层结构与潮汐和地下水影响的潜在梯度之间的关系。完全耦合的方法将使我们从两方面受益：(I)新方法将有助于理解地下植物相互作用的物理机制，并为考虑植物特性和非生物土壤参数的基于个体的模型开辟新的植物相互作用方法；(Ii)采用植被分区模式将使我们能够获得关于地下含水层结构和参数的信息。作为一个试点研究案例，我们提出了红树林生态系统。我们假设，盐度梯度是单一植物和植物群落尺度上的格局之间的明显联系，并且-由于它们对土壤水的物理性质的影响-土壤和地下水基质中的水动力学过程。在我们的方法中，根和地下水交界处的盐度将在植物方面控制水分吸收(渗透势)，并塑造植物的生长和异速生长。吸水(渗透排盐)会增加盐度。盐度(密度梯度)将增加潮汐和地下水梯度，作为地下水流动过程的驱动因素，反之亦然，在时间和空间上成为植物发展的边界条件。因此，地带性及其干扰应归因于地下非均质性。Bettina植物生长模型中的水势概念为土壤基质中的水动力过程提供了一个有效的接口，这可以用OpenGeoSys来描述。通过这种组合，我们将能够可靠地预测植物的物种分布和异速生长特征(树木大小、根径等)。来自土壤和地下水流动和输送过程所支配的非生物边界条件。这将使我们能够在生态植物群落和地下水建模方面共同取得进展：首先，我们将能够从植被参数(如分区模式或树木尺寸)中反向得出关于区域属性和浅层地下水系统的异质性的结论；其次，我们将开发更复杂的概念竞争替代方法，与现有的竞争替代方法不同，该方法将考虑非生物环境或各向异性条件的特征。

With the proposed project, we intend to extend the knowledge and process understanding of the interactions between vegetation and subsurface hydrodynamics by developing and employing a new, fully coupled plant-soil water modelling approach for mangrove ecosystems. Specifically, we want to gain insight into the relationships between (i) visible vegetation patterns like allometry, species composition and zonation and (ii) subsurface aquifer structures and potential gradients by tidal and ground water influence. The fully coupled approach will allow us to benefit equally on both sides: for (i), the new approach will help to understand the physical mechanisms of below-ground plant interaction and open the way for a new plant interaction approach for individual based models considering plant properties and abiotic soil parameters; for (ii), adopting vegetation zonation patterns will enable us to gain information on subsurface aquifer structures and parametrization. As a pilot study case we propose the mangrove ecosystem. We hypothesize, that salinity gradients are the obvious link between patterns on the single plant and plant community scale, and - due to their impact on physical properties of the soil water - the hydrodynamic processes in the soil and groundwater matrix. In our approach salinity at the interface between roots and groundwater will on the plant side control water uptake (osmotic potential) and shape plant growth and allometry. Water uptake (osmotic salt exclusion) will increase salinity. Salinity (density gradients) will add to tidal and groundwater gradients as a driver for groundwater flow processes and vice versa temporally and spatially emerge as a boundary condition for plant development. Zonation and its disturbance should thus be attributable to subsurface heterogeneity. The water potential concepts in the BETTINA plant growth model provide an effective interface to the hydrodynamic processes in the soil matrix which can be described by OpenGeoSys. With this combination, we will be able to reliably predict species distribution and allometric characteristic of plants (tree size, root diameter etc.) from abiotic boundary conditions governed by soil and groundwater flow and transport processes. This will allow us to jointly advance in both, ecological plant community and groundwater modelling: firstly, we will be able to conclude reversely from vegetation parameters as zonation patterns or tree dimensions on domain properties and the heterogeneity of the shallow groundwater system (groundwater view); secondly, we will develop a more sophisticated conceptual competition surrogate approach, which will, in contrast to existing ones like Field of Neighbourhood, take into account characteristics of the abiotic environment or anisotropic conditions.