A model for water uptake by plant roots
A model for water uptake by plant roots
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DOI：
10.1016/j.jtbi.2003.12.012
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发表时间：
2004-05-21
影响因子：
2
通讯作者：
Fowler, AC
中科院分区：
文献类型：
--
作者：
Roose, T;Fowler, AC
提出了一个非饱和土壤中植物根系吸水模型。该模型包括根系网络内部和土壤中的水的同时流动。首先考虑单个根系的吸水，然后利用参数化结果建立发育根系网络的吸水模型。我们专注于我们的模型上的一年生植物，特别是该模型将适用于商业单作，如玉米，小麦等模型进行数值求解，并与近似解析解的结果进行比较。该模型预测，由于植物根系吸水，土壤中将形成干区和湿区。湿润区位于土壤表面附近，其深度由降雨量和吸水率之间的平衡决定。由于部分饱和土壤中水流的非线性性质，土壤表面的降雨影响不会到达该区域，因此干燥区直接在潮湿区下方发展。本文导出了湿区深度的近似解析表达式，并简要讨论了湿区深度对植物的生态学意义。使用这个模型，我们还解决了这个问题的吸水网站集中在根系。该模型表明，靠近根系基部（即靠近地面）和靠近根尖的区域将比根系的中间区域吸收更多的水，这也是由于土壤中水流的高度非线性性质。(C)2003 Elsevier Ltd.保留所有权利。
We present a model for water uptake by plant roots from unsaturated soil. The model includes the simultaneous flow of water inside the root network and in the soil. It is constructed by considering first the water uptake by a single root, and then using the parameterized results thereby obtained to build a model for water uptake by the developing root network. We focus our model on annual plants, in particular the model will be applicable to commercial monocultures like maize, wheat, etc. The model is solved numerically, and the results are compared with approximate analytic solutions. The model predicts that as a result of water uptake by plant roots, dry and wet zones will develop in the soil. The wet zone is located near the surface of the soil and the depth of it is determined by a balance between rainfall and the rate of water uptake. The dry zone develops directly beneath the wet zone because the influence of the rainfall at the soil surface does not reach this region, due to the nonlinear nature of the water flow in the partially saturated soil. We develop approximate analytic expressions for the depth of the wet zone and discuss briefly its ecological significance for the plant. Using this model we also address the question of where water uptake sites are concentrated in the root system. The model indicates that the regions near the base of the root system (i.e. close to the ground surface) and near the root tips will take up more water than the middle region of the root system, again due to the highly nonlinear nature of water flow ill the soil. (C) 2003 Elsevier Ltd. All rights reserved.