Influence of root characteristics and soil variables on the uprooting mechanics of Avena sativa and Medicago sativa seedlings
Influence of root characteristics and soil variables on the uprooting mechanics of Avena sativa and Medicago sativa seedlings
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DOI：
10.1002/esp.3587
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发表时间：
2014-08-01
影响因子：
3.3
通讯作者：
Perona, Paolo
中科院分区：
文献类型：
--
作者：
Edmaier, Katharina;Crouzy, Benoit;Perona, Paolo
生长在河床上的幼苗和更新的木质残体的成功取决于它们简单的根结构所提供的对流动的抵抗力。在水槽实验中使用燕麦和苜蓿幼苗作为幼年河岸植物的原型。很少有人知道的根锚定力的大小和作用，这样简单的根系次生根system.We进行了1550垂直拔根实验燕麦和紫花苜蓿幼苗生长在石英砂。使用由计算机控制的马达驱动的轮通过直接牵引将幼苗拔起，并记录力。根进行扫描和建筑参数（根长度和根数）确定。拔根力和功（施加的力乘以施加的距离的积分），然后与根构型和土壤变量。根-土系统对拔根的初始响应表现为线弹性行为，模量随树龄的增加而增加。虽然最大拔根力被发现与总根长线性增加，并主要取决于主根的长度，拔根工作遵循幂律，并与整个根系。因此，对于我们所考虑的年轻植物，次生根负责在持续时间而不是强度方面抵抗环境干扰的能力。初生根和次生根之间的这种区别对于在河坝和岛屿上发芽的河岸物种的幼苗至关重要，在这些地方，洪水是死亡的主要原因。除了澄清土壤和根变量的生物力学作用，得到的连根拔起的统计数据是有用的解释和设计ecomorphodynamic水槽实验。版权所有（C）2014约翰威利父子有限公司
The success of seedlings and rejuvenated woody debris growing on river bedforms depends on the resistance to uprooting by flow provided by their simple root architecture. Avena sativa and Medicago sativa seedlings were used in flume experiments as prototypes for juvenile riparian plants. Very little is known about the magnitude of root anchoring forces and the role of secondary roots of such simple root systems.We performed 1550 vertical uprooting experiments on Avena sativa and Medicago sativa seedlings grown in quartz sand. Seedlings were pulled up by direct traction using a wheel driven by a computer-controlled motor and the force was recorded. Roots were scanned and architectural parameters (root length and number of roots) determined. Uprooting force and work (the integral of the applied force times the distance over which it is applied) were then related to root architecture and soil variables.Resistance to uprooting increased with decreasing sediment size and sediment moisture content. The initial response of the root-soil system to uprooting showed linear elastic behaviour with modulus increasing with plant age. While the maximum uprooting force was found to increase linearly with total root length and be mainly dependent on the length of the main root, uprooting work followed a power law and has to be related to the whole root system. Thus, for the young plants we considered, secondary roots are responsible for the ability to withstand environmental disturbances in terms of duration rather than magnitude. This distinction between primary and secondary roots can be of crucial importance for seedlings of riparian species germinating on river bars and islands where inundation is a main cause of mortality. Beyond clarifying the biomechanical role of soil and root variables, the uprooting statistics obtained are useful in interpreting and designing ecomorphodynamic flume experiments. Copyright (C) 2014 John Wiley & Sons, Ltd.