Tron Stefania, Laio Francesco, Ridolfi Luca
Department of Environment, Land and Infrastructure Engineering, Politecnico di Torino, Turin, Italy.
J Theor Biol. 2014 Nov 7;360:102-108. doi: 10.1016/j.jtbi.2014.06.035. Epub 2014 Jul 8.
The vertical root distribution of riparian vegetation plays a relevant role in soil water balance, in the partition of water fluxes into evaporation and transpiration, in the biogeochemistry of hyporheic corridors, in river morphodynamics evolution, and in bioengineering applications. The aim of this work is to assess the effect of the stochastic variability of the river level on the root distribution of phreatophytic plants. A function describing the vertical root profile has been analytically obtained by coupling a white shot noise representation of the river level variability to a description of the dynamics of root growth and decay. The root profile depends on easily determined parameters, linked to stream dynamics, vegetation and soil characteristics. The riparian vegetation of a river characterized by a high variability turns out to have a rooting system spread over larger depths, but with shallower mean root depths. In contrast, a lower river variability determines root profiles with higher mean root depths.
河岸植被的垂直根系分布在土壤水分平衡、水分通量在蒸发和蒸腾之间的分配、潜流带的生物地球化学、河流地貌动力学演变以及生物工程应用中发挥着重要作用。这项工作的目的是评估河流水位的随机变化对潜水植物根系分布的影响。通过将河流水位变化的白噪声表示与根系生长和衰退动力学描述相结合，解析得到了一个描述垂直根系分布的函数。根系分布取决于与河流动力学、植被和土壤特性相关的易于确定的参数。结果表明，具有高变异性的河流的河岸植被具有分布在更大深度但平均根深度较浅的根系系统。相比之下，较低的河流水位变异性决定了具有较高平均根深度的根系分布。
