From active to stable: Paraglacial transition of Alpine lateral moraine slopes
From active to stable: Paraglacial transition of Alpine lateral moraine slopes
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DOI：
10.1002/ldr.3140
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发表时间：
2018-10
影响因子：
4.7
通讯作者：
J. Eichel;D. Draebing;N. Meyer
中科院分区：
文献类型：
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作者：
J. Eichel;D. Draebing;N. Meyer
许多正在消退的阿尔卑斯山谷冰川留下了巨大的侧向冰川。在许多高山环境中，地貌过程对这些地貌的改造是最重要的副冰川过程之一。虽然有几项研究调查了通过冲刷过程进行的冰雹改造，但人们并不清楚当冲刷停止时会发生什么，以及为什么以及何时冰雹侧坡变得稳定。这项研究通过结合地貌和生态数据来评估潜在的影响因素、完成冰缘调整的指标及其时空格局，从而加深了对高山侧坡从活跃到稳定的冰缘过渡的理解。对瑞士特尔特曼冰川前陆的三个侧面冰川复合体进行了地貌生态永久样地调查和地貌制图。随后，使用多变量统计方法分析了永久曲线图数据。我们的研究表明，通过定植植物物种、坡面地貌和物质性质进行的生态工程是影响副冰川从活跃的斜坡向稳定的斜坡过渡的重要因素。一旦垂直植被层和土层发育，地貌过程往往不存在，这表明成熟的植被和先进的土壤发育是边坡稳定和完成副冰川调整的有价值的指标。在一个概念模型中，我们将高山冰川侧坡的共生过渡描述为一个时间序列，在这个序列中，冲刷(阶段I)、冲刷(阶段II)、最后稳定(阶段III)相继发生。在空间上，副胎盘调节是异质性的，由此产生的模式可以通过识别的影响因素来解释。
Many retreating Alpine valley glaciers leave large lateral moraines behind. Reworking of these landforms by geomorphic processes is one of the most important paraglacial processes in many Alpine environments. Although several studies investigated moraine reworking by gullying processes, it is not well known what happens when gullying ceases and why and when lateral moraine slopes become stable. This study improves the understanding of the paraglacial transition from active to stable Alpine lateral moraine slopes by assessing potential influencing factors, indicators for completed paraglacial adjustment, and its spatiotemporal patterns using a combination of geomorphic and ecologic data. A geomorphic and ecologic permanent plot survey and geomorphic mapping were carried out on three lateral moraine complexes in the Turtmann glacier foreland (Switzerland). Subsequently, permanent plot data were analysed using multivariate statistics. Our study suggests that ecosystem engineering by colonizing plant species, slope geomorphometry, and material properties are important factors influencing the paraglacial transition from active to stable slopes. Geomorphic processes are often absent once vertical vegetation layers and soil horizons develop, showing that mature vegetation and advanced soil development are valuable indicators for slope stability and completed paraglacial adjustment. In a conceptual model, we describe the paraglacial transition of Alpine lateral moraine slopes as a temporal sequence in which gullying (Stage I), solifluction (Stage II), and finally stabilization (Stage III) follow one after another. In space, paraglacial adjustment is heterogeneous, and resulting patterns can be explained by the identified influencing factors.