Short and long term feedback between vegetation and morphodynamic processes

考虑到1850-1920、1920-1980、1980-今天的时间片以及干扰和海拔梯度，将在微观(殖民)、中观(干扰后恢复)和宏观(景观变化)尺度上调查植物群落的演变、物种和功能多样性、植被-土壤-群落、植被对干扰和植被变化的反馈。我们假设：(1)冰冻圈的变化(冰川、永冻土、雪)影响殖民和群落演化；(2)植被、土壤和地貌/水文干扰之间存在密切的相互作用，导致特定的功能植物反应；(3)干扰促进范围转移，迁徙的物种具有特定的功能特征；(4)气候变化是时间片植被变化的基本驱动因素，最显著的影响发生在时间片1980-今天。第一个假设将沿着冰川前陆进行测试，概述初级演替过程和地貌动力学过程对演替物种的影响。第二个假设涉及所有三个研究区的植被对地貌和/或洪水事件的反馈，从树线到近冰川地带的海拔梯度。用功能方法研究了物种在扰动和未扰动场地上的反应。第三种方法将考虑物种从较低海拔向较高海拔的迁移，以及干扰是否有助于从较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。利用多元统计方法，对植被数据进行环境、地貌/水动力和功能特征数据回归分析。所有数据都是模拟过去和未来植被的基准数据。

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.