Mangrove-Saltmarsh ecotone patterns as indicators for critical impacts of sea level rise and climate change on coastal wetlands – MASCOT

背景：（亚）热带沿海湿地通常由红树林和盐沼组成。虽然红树林大多位于经常被洪水淹没的地区，但盐沼占主导地位的是上部干燥，通常是高盐区。这两种生境类型之间的过渡被称为“红树林-盐沼过渡带”，它是非生物因子对红树林和盐沼植被不同影响的指示器。与此同时，植物改变了当地的非生物和生物环境。这些双向反馈导致了特征性的植被格局，例如，反映在植被的高度结构及其从突变到扩散的过渡的尖锐性上。由于非生物条件的变化导致生态交错带及其植被格局内的级联效应，它们可能是气候引起的变化及其对沿海稳定性和生态系统服务的影响的极好指标。研究山区和北方树木谱系的转变，因此，我们假设红树林盐沼生态交错带的形状是关键，预测他们对气候引起的changes.Aim的反应：通过这个项目，我们希望有助于对生态交错带模式及其动态的机制的一般理解。我们希望了解洪水与淡水输入相结合如何塑造植物群落，植物如何设计它们的栖息地，这些相互作用如何导致观察到的栖息地类型的分区，它们的过渡区是如何形成的，以及在海平面上升和降雨量变化的情况下可以预期什么趋势。这将使我们能够使用的红树林-盐-沼泽交错带的模式的变化，观察到的和预测的水文制度的（亚）热带coasts.Methods的变化的关键影响的指标：我们将延长机械模拟模型方法MANGA的红树林生态系统的几个组成部分。这些包括盐沼植物的描述，盐沼所需的不饱和土层，红树林的生理可塑性。新的Mascot模型将描述盐沼植物、红树林灌木、红树林和土壤水之间的相互作用，从而可以模拟整个红树林-盐沼交错带。我们将与来自南美洲和中美洲、亚洲和澳大利亚的合作伙伴一道，系统地调查在不断变化的水文条件下不同生态交错带模式的出现、持续和时间变化。在此基础上，我们将制定指标，通过生态交错区格局的时空变化，可以在早期阶段检测到环境变化的强度和动态。

Background: (Sub)tropical coastal wetlands often consist of mangroves and salt marshes. While mangroves are mostly located in the regularly flooded zone, salt marshes dominate the upper drier, often hypersaline zone. The transition between the two habitat types is called "mangrove-saltmarsh ecotone" and is an indicator of the different effects of abiotic factors on mangrove and salt marsh vegetation. At the same time, plants change their local abiotic and biotic environment. These bidirectional feedbacks result in characteristic vegetation patterns that are reflected, for example, in the height structure of the vegetation and the sharpness of their transition, from abrupt to diffuse. Since changes in abiotic conditions lead to cascading effects within ecotones and their vegetation patterns, they might be excellent indicators of climate-induced changes and their consequences for coastal stability and ecosystem services. Following research on mountainous and boreal tree lineage shifts, we therefore hypothesise that the shape of mangrove-saltmarsh ecotones is the key to predicting their response to climate-induced change.Aim: With this project we want to contribute to the general understanding of the mechanisms underlying ecotone patterns and their dynamics. We want to understand how the flooding regime in combination with freshwater input shapes the plant community, how plants engineer their habitat, how these interactions lead to the observed zonation of habitat types, how their transition zone is formed and what trends can be expected under rising sea level and under altered rainfall regimes. This will allow us to use changes in patterns of mangrove-salt-marsh ecotones as indicators of critical impacts of observed and predicted changes in the hydrological regime of (sub)tropical coasts.Methods: We will extend the mechanistic simulation model approach MANGA for mangrove ecosystems by several components. These include the description of saltmarsh plants, the unsaturated soil layer required for saltmarshes, and the physiological plasticity of mangroves. The new Mascot model will describe the interactions between saltmarsh plants, mangrove shrubs, mangrove trees and soil water and thus allow the simulation of the entire mangrove-saltmarsh ecotone. Together with cooperation partners from South and Central America, Asia and Australia, we will systematically investigate the emergence, persistence and temporal shift of different ecotone patterns under changing hydrological conditions. Based on this, we will develop indicators by which the intensity and dynamics of environmental changes through spatio-temporal shifts in ecotone patterns can be detected at an early stage.