根系吸水的最小能量模型的实验验证与评价

Experimental Validation and Evaluation of Minimum Energy Model on Root Water Exaction

根系吸水的定量模拟是土—根系统水分动力学研究的难点之一。现有根系吸水模拟模型往往是在特定条件下建立的,缺乏对根系吸水机制的了解,因而其应用受到限制。根系吸水的最小能量模型是基于植物为适应生存,用于根系吸收水分消耗的能量最小这一物理概念上提出来,是否能真实反映根系吸水情况值得进一步研究。采用土柱实验,对该模型进行了实验验证。发现正常水分条件下,最小能量模型模拟精度高,而在土壤干旱条件下模拟精度较差,可能与干旱条件下植物体内的生物调节机制有关。

The quantitative modeling of root water exaction is difficult in research on soil-root hydraulic dynamics. Present models were constructed under certain ideal conditions and based on poor understandings of the mechanisms of root water exaction and thus their applications were rather limited. The minimum energy model was presented based on the physical concept that plant would consume minimum energy for root water exaction in order to survive. But it is not clear if this theory could truly reflect root water exaction. In this research, a soil column experiment was conducted to validate the model. Results indicate that the model had a higher modeling precision under normal water condition, while the modeling precision decreased under drought condition. The reason may be related with the biological mechanism inside plant themselves.