scholarly journals Water uptake by cotton root systems: an examination of assumptions in the single root model

1974 ◽  
Author(s):  
H.M. Taylor ◽  
B. Klepper
Keyword(s):  
Water Uptake ◽  
Root Systems ◽  
Single Root ◽  
Cotton Root ◽  
Root Model

scholarly journals Parameterizing complex root water uptake models – the arrangement of root hydraulic properties within the root architecture affects dynamics and efficiency of root water uptake

2014 ◽  
Vol 11 (1) ◽  
pp. 757-805 ◽  
Author(s):  
M. Bechmann ◽  
C. Schneider ◽  
A. Carminati ◽  
D. Vetterlein ◽  
S. Attinger ◽  
...  
Keyword(s):  
Root System ◽  
Water Uptake ◽  
Plant Resistance ◽  
Hydraulic Properties ◽  
Three Dimensional ◽  
Root Systems ◽  
Root Water Uptake ◽  
Hydraulic Lift ◽  
Excessive Bleeding ◽  
Single Root

Abstract. Detailed three-dimensional models of root water uptake have become increasingly popular for investigating the process of root water uptake. However they suffer from a lack of information in important parameters, especially distribution of root hydraulic properties. In this paper we explore the role that arrangement of root hydraulic properties and root system topology play for modelled uptake dynamics. We apply microscopic models of single root structures to investigate the mechanisms shaping uptake dynamics and demonstrate the effects in a complex three dimensional root water uptake model. We introduce two efficiency indices, for (a) overall plant resistance and (b) water stress and show that an appropriate arrangement of root hydraulic properties can increase modelled efficiency of root water uptake in single roots, branched roots and entire root systems. The average uptake depth of the complete root system was not influenced by parameterization. However, other factors such as evolution of collar potential, which is related to the plant resistance, root bleeding and redistribution patterns were strongly affected by the parameterization. Root systems are more efficient when they are assembled of different root types, allowing for separation of root function in uptake (short young) roots and transport (longer mature) roots. Results become similar, as soon as this composition is accounted for to some degree (between 40 and 80% of young uptake roots). Overall resistance to root water uptake was decreased up to 40% and total transpiration was increased up to 25% in these composed root systems, compared to homogenous root systems. Also, one parameterization (homogenous young root system) was characterized by excessive bleeding (hydraulic lift), which was accompanied by lowest efficiency. We conclude that heterogeneity of root hydraulic properties is a critical component of complex three dimensional uptake models. Efficiency measures together with information on critical xylem potentials may be useful in parameterizing root property distribution.

WATER UPTAKE BY COTTON ROOT SYSTEMS

Soil Science ◽  
1975 ◽  
Vol 120 (1) ◽  
pp. 57-67 ◽  
Author(s):  
H. M. TAYLOR ◽  
B. KLEPPER
Keyword(s):  
Water Uptake ◽  
Root Systems ◽  
Cotton Root

scholarly journals Towards understanding tree root profiles: simulating hydrologically optimal strategies for root distribution

2001 ◽  
Vol 5 (4) ◽  
pp. 629-644 ◽  
Author(s):  
M. T. van Wijk ◽  
W. Bouten
Keyword(s):  
Water Uptake ◽  
Root Distribution ◽  
Root Zone ◽  
Evolutionary Game ◽  
Optimal Strategies ◽  
Single Root ◽  
Root Interactions ◽  
Model Configuration ◽  
The One ◽  
Root Distributions

Abstract. In this modelling study differences in vertical root distributions measured in four contrasting forest locations in the Netherlands were investigated. Root distributions are seen as a reflection of the plant’s optimisation strategy, based on hydrological grounds. The "optimal" root distribution is defined as the one that maximises the water uptake from the root zone over a period of ten years. The optimal root distributions of four forest locations with completely different soil physical characteristics are calculated using the soil hydrological model SWIF. Two different model configurations for root interactions were tested: the standard model configuration in which one single root profile was used (SWIF-NC), and a model configuration in which two root profiles compete for the same available water (SWIF-C). The root profiles were parameterised with genetic algorithms. The fitness of a certain root profile was defined as the amount of water uptake over a simulation period of ten years. The root profiles of SWIF-C were optimised using an evolutionary game. The results showed clear differences in optimal root distributions between the various sites and also between the two model configurations. Optimisation with SWIF-C resulted in root profiles that were easier to interpret in terms of feasible biological strategies. Preferential water uptake in wetter soil regions was an important factor for interpretation of the simulated root distributions. As the optimised root profiles still showed differences with measured profiles, this analysis is presented, not as the final solution for explaining differences in root profiles of vegetation but as a first step using an optimisation theory to increase understanding of the root profiles of trees. Keywords: forest hydrology, optimisation, roots

Water drawdown by radish (Raphanus sativus L.) multiple-root systems evaluated using computed tomography

Soil Research ◽  
2008 ◽  
Vol 46 (3) ◽  
pp. 228
Author(s):  
M. A. Hamza ◽  
S. H. Anderson ◽  
L. A. G. Aylmore
Keyword(s):  
Computed Tomography ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Uptake ◽  
Root Zone ◽  
Multiple Root ◽  
Root Systems ◽  
Bulk Soil ◽  
Water Drawdown

Although measurements of water drawdown by single radish root systems have been previously published by the authors, further research is needed to evaluate water drawdown patterns in multiple-root systems. The objective of this study was to compare water transpiration patterns estimated using X-ray computed tomography (CT) with the traditional gravimetric method and to evaluate the effects of variably spaced multiple root systems on soil water content and corresponding water content gradients. Water drawdown showed a dual pattern in which it increased rapidly when soil water content was high at the beginning of transpiration, then slowed down to an almost constant level with time as water content decreased. These results contrast with the single-root system wherein transpiration rates initially increased rapidly and then slowly increased with time. Water uptake estimated using the CT method was observed to be 27–38% lower than the gravimetrically estimated water uptake; this difference was attributed to lower water uptake for the upper 30 mm layer (CT measured) than lower layers due to differences in root density. However, good correlation (r = 0.97) was found between both measurement methods. The drawdown patterns for multiple root systems showed a convex shape from the root surface to the bulk soil, compared with a nearly linear shape for single roots. The water content drawdown areas and the drawdown distances for multiple root systems were found to be much larger than those corresponding to single radish roots. Differential water content gradients were observed for roots spaced at 15-mm distances compared with 3–4-mm distances. These differential gradients from the bulk soil towards the root-zone occurred probably creating localised water potential gradients within the root-zone, which moved water from between roots to root surfaces. The lowest water content values were located in the inter-root areas. The CT-scanned layer probably acted as one drawdown area with particularly higher water drawdown from the inter-root areas.

Seasonal water uptake and movement in root systems of Australian phraeatophytic plants of dimorphic root morphology: a stable isotope investigation

Oecologia ◽  
1996 ◽  
Vol 107 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Todd E. Dawson ◽  
John S Pate
Keyword(s):  
Stable Isotope ◽  
Water Uptake ◽  
Root Morphology ◽  
Root Systems

Water uptake regulation in peach trees with split-root systems

1994 ◽  
Vol 17 (4) ◽  
pp. 379-388 ◽  
Author(s):  
T. SIMONNEAU ◽  
R. HABIB
Keyword(s):  
Water Uptake ◽  
Root Systems ◽  
Split Root ◽  
Peach Trees

scholarly journals Traits and selection strategies to improve root systems and water uptake in water-limited wheat crops

2012 ◽  
Vol 63 (9) ◽  
pp. 3485-3498 ◽  
Author(s):  
A. P. Wasson ◽  
R. A. Richards ◽  
R. Chatrath ◽  
S. C. Misra ◽  
S. V. S. Prasad ◽  
...  
Keyword(s):  
Water Uptake ◽  
Root Systems ◽  
Selection Strategies

A MODEL FOR WATER UPTAKE AND DEVELOPMENT OF ROOT SYSTEMS

Soil Science ◽  
1987 ◽  
Vol 144 (5) ◽  
pp. 352-366 ◽  
Author(s):  
ANGELOS L. PROTOPAPAS ◽  
RAFAEL L. BRAS
Keyword(s):  
Water Uptake ◽  
Root Systems

scholarly journals Effect of parameter choice in root water uptake models – the arrangement of root hydraulic properties within the root architecture affects dynamics and efficiency of root water uptake

2014 ◽  
Vol 18 (10) ◽  
pp. 4189-4206 ◽  
Author(s):  
M. Bechmann ◽  
C. Schneider ◽  
A. Carminati ◽  
D. Vetterlein ◽  
S. Attinger ◽  
...  
Keyword(s):  
Root System ◽  
Water Uptake ◽  
Root Length ◽  
Hydraulic Properties ◽  
Three Dimensional ◽  
Root Systems ◽  
Root Water Uptake ◽  
Hydraulic Lift ◽  
Hydraulic Redistribution ◽  
Young Root

Abstract. Detailed three-dimensional models of root water uptake have become increasingly popular for investigating the process of root water uptake. However, they suffer from a lack of information on important parameters, particularly on the spatial distribution of root axial and radial conductivities, which vary greatly along a root system. In this paper we explore how the arrangement of those root hydraulic properties and branching within the root system affects modelled uptake dynamics, xylem water potential and the efficiency of root water uptake. We first apply a simple model to illustrate the mechanisms at the scale of single roots. By using two efficiency indices based on (i) the collar xylem potential ("effort") and (ii) the integral amount of unstressed root water uptake ("water yield"), we show that an optimal root length emerges, depending on the ratio between roots axial and radial conductivity. Young roots with high capacity for radial uptake are only efficient when they are short. Branching, in combination with mature transport roots, enables soil exploration and substantially increases active young root length at low collar potentials. Second, we investigate how this shapes uptake dynamics at the plant scale using a comprehensive three-dimensional root water uptake model. Plant-scale dynamics, such as the average uptake depth of entire root systems, were only minimally influenced by the hydraulic parameterization. However, other factors such as hydraulic redistribution, collar potential, internal redistribution patterns and instantaneous uptake depth depended strongly on the arrangement on the arrangement of root hydraulic properties. Root systems were most efficient when assembled of different root types, allowing for separation of root function in uptake (numerous short apical young roots) and transport (longer mature roots). Modelling results became similar when this heterogeneity was accounted for to some degree (i.e. if the root systems contained between 40 and 80% of young uptake roots). The average collar potential was cut to half and unstressed transpiration increased by up to 25% in composed root systems, compared to homogenous ones. Also, the least efficient root system (homogenous young root system) was characterized by excessive bleeding (hydraulic lift), which seemed to be an artifact of the parameterization. We conclude that heterogeneity of root hydraulic properties is a critical component for efficient root systems that needs to be accounted for in complex three-dimensional root water uptake models.

Modeling Soil-Coupled Water Uptake of Multiple Root Systems with Automatic Time Stepping

2011 ◽  
Vol 10 (2) ◽  
pp. 727-735 ◽  
Author(s):  
T. Kalbacher ◽  
C. L. Schneider ◽  
W. Wang ◽  
A. Hildebrandt ◽  
S. Attinger ◽  
...  
Keyword(s):  
Water Uptake ◽  
Multiple Root ◽  
Root Systems ◽  
Time Stepping
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