Water uptake by two contrasting root systems (maize, peach tree): results from a model of hydraulic architecture

This article aims at showing how consideration of architectural and hydraul ic features of root systems can help in the understanding of water uptake b y plants. Relevant data on architecture and hydraulics of roots can be brou ght together in the 'Hydraulic Tree Model of the root system, a model that couples a root system architecture model and laws for water flow to and int o roots. In this way, a detailed portrait of water absorption is given, fro m the single root to the whole root system. Two contrasting plants, maize a nd peach tree, illustrate model applications and results. These plants not only differ in architectural features, but also in the distribution of hydr aulic conductance in the root system. Maize uptake pattern is highly hetero geneous, showing patches of high absorption rates distributed throughout th e root system. In contrast, the peach tree is characterized by a localized uptake in the upper, proximal part of the root system. ((C) Inra/Elsevier, Paris.).