Transpiration, a process by which plants extract water from soil and transmit it to the atmosphere, is a vital (yet least quantified) component of the hydrological cycle. We propose a root-scale model of water uptake, which is based on first principles, i.e. employs the generally accepted Richards equation to describe water flow in partially saturated porous media (both in a root and the ambien...

In plants, the nitrate transporters, NRT1.1 and NRT2.1, are mainly responsible for nitrate uptake. Intriguingly, both nitrate transporters are located in a complementary manner in different cells layers of the mature root suggesting that their coordination should occur during nitrate uptake and plant growth. This hypothesis was examined on 5-d-old rape seedlings grown on agar medium supplemente...

Fine root dynamics control a dominant flux of carbon from plants and into soils and mediate potential uptake and cycling of nutrients and water in terrestrial ecosystems. Understanding of these patterns is needed to accurately describe critical processes like productivity and carbon storage from ecosystem to global scales. However, limited observations of root dynamics make it difficult to defi...

This study determined whether the field level concentration of root zone CO2 affects transpiration rate and root water transport in soybean (Glycine max L. Merr.). In an upland field converted from a paddy field, topsoil CO2 during the cropping season rose to 8 kPa of partial pressure after rainfall, whereas O2 dropped only to a minimum of 7 kPa. An elevated root zone CO2 pressure of 6 kPa sign...

Transpiration in water-limited ecosystems is controlled by the availability of soil moisture. Rain events in these natural environments may only partially wet the root zone, leading to a heterogeneous distribution of available water. This spatial variability coupled with the non-linearity of the function relating local uptake to local saturation produces a non-unique relationship when these qua...

BACKGROUND AND AIMS Most plant scientists, in contrast to animal scientists, study only half the organism, namely above-ground stems, leaves, flowers and fruits, and neglect below-ground roots. Yet all acknowledge roots are important for anchorage, water and nutrient uptake, and presumably components of yield. This paper investigates the relationship between domestication, and the root systems ...

Taxonomic Recent trends in the management of water supply have increased the need for modeling techniques that can provide reliable, efficient, and accurate representation of the nonlinear dynamics of water quality within water distribution systems. Since artificial neural networks have been widely applied to the nonlinear transfer function approximation, in this study we present an empirical m...

[1] In groundwater-dependent ecosystems, interactions between rainfall, water table fluctuations, and vegetation are exerted through the soil water content. The dynamics of soil moisture, in fact, are strongly coupled to fluctuations of the water table and, together, they control the overall ecosystem dynamics. We propose here a simple process-based stochastic model for the study of soil moistu...

Water transport was examined in solution culture grown seedlings of aspen (Populus tremuloides) after short-term exposures of roots to exogenous ethylene. Ethylene significantly increased stomatal conductance, root hydraulic conductivity (L(p)), and root oxygen uptake in hypoxic seedlings. Aerated roots that were exposed to ethylene also showed enhanced L(p). An ethylene action inhibitor, silve...