Short and long term feedback between vegetation and morphodynamic processes

考虑1850-1920、1920-1980、1980-今天的时间片以及扰动和海拔梯度，将在微观（定植）、中观（扰动后恢复）和宏观尺度（景观变化）上研究植物群落、物种和功能多样性、植被-土壤关联、植被对扰动和植被变化的反馈的演变。我们假设：(i)冰冻圈的变化（冰川、永久冻土、积雪）影响定植和群落进化；（ii）植被、土壤和地貌/水文扰动之间存在密切的相互作用，导致特定的功能性植物响应；（iii）干扰促进范围转移，迁徙物种具有特定的功能特征；（iv）气候变化是时间片植被变化的主要驱动因素，1980年至今天的时间片对气候变化的影响最为显著。第一个假设将沿着冰川前陆进行测试，概述原始演替过程和形态动力学过程对演替物种的影响。第二个假设涉及植被对地形和/或洪水事件的反馈，在所有三个研究区域沿海拔梯度从树线到低寒带。采用功能分析方法，研究了受干扰和未受干扰地点物种的响应。第三种方法将解释物种从低海拔到高海拔的迁移，以及干扰是否有助于从低海拔建立物种的问题。对于第四个假设，我们将分析和评估整个时间片的土地覆盖变化。采用多元统计方法，对植被数据进行环境、地貌/水文和功能性状数据的回归。所有数据都可作为模拟过去和未来植被的基线数据。

The evolution of plant communities, species and functional diversity, vegetation-soil-associations, feedback of the vegetation to disturbances and vegetation changes will be investigated at micro- (colonization), meso- (restoration after disturbance) and macroscales (landscape changes), considering the time slices 1850-1920, 1920-1980, 1980-today as well as disturbance and elevation gradients. We hypothesize that (i) cryospheric changes (glacier, permafrost, snow) influence colonization and community evolution; (ii) a close interaction exists between vegetation, soil and geomorphological/hydrological disturbances, resulting in specific functional plant responses; (iii) disturbances facilitate range shifts and the migrating species are characterized by specific functional traits; (iv) climate change is the essential driver of vegetation changes for the time slices, the most pronounced effects occurring for the time slice 1980-today. The first hypothesis will be tested along a glacier foreland, outlining processes of primary succession and effects of morphodynamic processes on successional species. The second hypothesis deals with vegetation feedback to geomorphological and/or flood events along elevation gradients from the treeline to the subnival zone at all three study areas. By means of a functional approach, responses of species are studied on disturbed and undisturbed sites. The third approach will account for species migrations from lower to higher altitudes and for the question if disturbances facilitate the establishment of species from lower altitudes. For the fourth hypothesis we will analyse and evaluate the land cover changes throughout the time slices. By means of multivariate statistics, vegetation data will be regressed on environmental, geomorphic/hydromorphic and functional trait data. All data serve as baseline data for modelling past and future vegetation.