Conditions for feedbacks between geomorphic and vegetation dynamics on lateral moraine slopes: a biogeomorphic feedback window
Conditions for feedbacks between geomorphic and vegetation dynamics on lateral moraine slopes: a biogeomorphic feedback window
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DOI：
10.1002/esp.3859
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发表时间：
2016-03-15
影响因子：
3.3
通讯作者：
Dikau, Richard
中科院分区：
文献类型：
--
作者：
Eichel, Jana;Corenblit, Dov;Dikau, Richard
小冰期侧碛是冰川前陆最重要的沉积物贮存区和动力区之一。冰川退缩后，同时进行的冰缘调整和植被演替影响冰碛斜坡。地貌过程（如泥石流、细沟间侵蚀、冲沟、土壤侵蚀）干扰和限制植被的发展，而植被覆盖的增加则减少地貌活动。因此，地貌和植被动态之间的反馈强烈控制冰碛边坡的发展。然而，人们对这些生物地貌反馈发生的条件还没有充分了解，并且仍然存在重大知识差距。本研究确定反馈条件，通过分析的地貌和植被数据，从永久地块在Turtmann冰川前陆，瑞士。多元统计分析结果表明：（1）八瓣鱼藤是一种重要的药用植物;是一种高山生态系统工程种，影响地貌过程的侧碛，从而控制生态系统的结构和功能，（ii）表明，地貌反馈可以发生一旦地貌活动充分减少D。八爪龙来建立并越过一个掩护阈值。在随后的生态系统工程过程中，主导地貌过程由流滑向束缚土冲转变。边坡稳定性的增加导致了非地貌反馈的下降和D。八瓣花灌木。我们概念化的过程的幅度，频率和物种的弹性和抗干扰能力之间的关系，在一个“生态反馈窗口”的概念。我们的方法增强了了解地貌和高山植被动态之间的反馈侧冰碛斜坡，并强调了地貌和生态方法相结合的重要性，为古地貌研究。版权所有（c）2015约翰威利父子有限公司
Little Ice Age lateral moraines represent one of the most important sediment storages and dynamic areas in glacier forelands. Following glacier retreat, simultaneous paraglacial adjustment and vegetation succession affect the moraine slopes. Geomorphic processes (e.g. debris flows, interrill erosion, gullying, solifluction) disturb and limit vegetation development, while increasing vegetation cover decreases geomorphic activity. Thus, feedbacks between geomorphic and vegetation dynamics strongly control moraine slope development. However, the conditions under which these biogeomorphic feedbacks can occur are insufficiently understood and major knowledge gaps remain. This study determines feedback conditions through the analysis of geomorphic and vegetation data from permanent plots in the Turtmann glacier foreland, Switzerland. Results from multivariate statistical analysis (i) confirm that Dryas octopetala L. is an alpine ecosystem engineer species which influences geomorphic processes on lateral moraines and thereby controls ecosystem structure and function, and (ii) demonstrate that biogeomorphic feedbacks can occur once geomorphic activity sufficiently decreases for D. octopetala to establish and cross a cover threshold. In the subsequent ecosystem engineering process, the dominant geomorphic processes change from flow and slide to bound solifluction. Increasing slope stabilization induces a decline in biogeomorphic feedbacks and the suppression of D. octopetala by shrubs. We conceptualize this relationship between process magnitude, frequency and species resilience and resistance to disturbances in a biogeomorphic feedback window' concept. Our approach enhances the understanding of feedbacks between geomorphic and alpine vegetation dynamics on lateral moraine slopes and highlights the importance of integrating geomorphic and ecological approaches for biogeomorphic research. Copyright (c) 2015 John Wiley & Sons, Ltd.