Abstract
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 ambient soil) and makes no assumptions about the kinematic structure of flow in a root-soil continuum. Using the Gardner (exponential) constitutive relation to represent the relative hydraulic conductivities in the Richards equations and treating the root as a cylinder, we use a matched asymptotic expansion technique to derive approximate solutions for transpiration rate and the size of a plant capture zone. These solutions are valid for roots whose size is larger than the macroscopic capillary length of a host soil. For given hydraulic properties, the perturbation parameter used in our analysis relates a root’s size to the macroscopic capillary length of the ambient soil. This parameter determines the width of a boundary layer surrounding the soil-root interface, within which flow is strictly horizontal (perpendicular to the root). Our analysis provides a theoretical justification for the standard root-scale cylindrical flow model of plant transpiration that imposes a number of kinematic constraints on water flow in a root-soil continuum.
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References
Allen RG, Pereira LS, Raes D, Smith M (1998) Crop evapotranspiration—guidelines for computing crop water requirements. In: Technical Report FAO Irrigation and drainage paper 56, ISBN 92-5-104219-5, FAO—food and agriculture organization of the united nations
Alm DM, Cavelier J, Nobel PS (1992) A finite element method of radial and axial conductivitives for individual roots: development and validation for two desert succulents. Ann Bot 69:87–92
Arbogast T, Obeyesekere M, Wheeler MF (1993) Numerical methods for the simulation of flow in root-soil systems. SIAM J Numer Anal 30:1677–1702
Caldwell MM, Richars JH (1986) Competing root systems: morphology and models of absorption. In: Civnish TJ (ed) On the economy of plant form and function. Cambridge University Press, Cambridge, pp 251–273
Carminati A, Moradi AB, Vetterlein D, Weller U, Vogel H-J, Oswald SE (2010) Dynamics of soil water content in the rhizosphere. Plant Soil 332(1–2):163–176
Cohen IM, Kundu PK (2004) Fluid mechanics. Elsevier, New York
Cole JD (1968) Perturbation methods in applied mathematics. Blaisdell, New York
Couvreur V, Vanderborght J, Javaux M (2012) A simple three-dimensional macroscopic root water uptake model based on the hydraulic architecture approach. Hydrol Earth Syst Sci
Cowan IR (1965) Transport of water in the soil-plant-atmosphere system. J Appl Ecol 2:221–239
Dagan G (1968) A derivation of Dupuit solution of steady flow toward wells by matched asymptotic expansions. Water Resour Res 4:403–412
Dagan G (1971) Perturbation solutions of the dispersion equation in porous mediums. Water Resour Res 7:135–142
Day SD, Wiseman PE, Dickinson SB, Harris JR (2010) Contemporary concepts of root system architecture of urban trees. Arboric Urban For 36(4):149–159
De Jong-van-Lier Q, Metselaar K, van Dam JC (2006) Root water extraction and limiting soil hydraulic conditions estimated by numerical simulation. Vadose Zone J 5:1264–1277
Doussan C, Pages L, Vercambre G (1998) Modelling of the hydraulic architecture of root systems: an integrated approach to water absorption-model description. Ann Botany 81:213–223
De Willigen P, Van Noordwijk M (1994a) Mass flow and diffusion of nutrients to a root with constant or zero-sink uptake 1. Constant uptake. Soil Sci 157:162–170
De Willigen P, Van Noordwijk M (1994b) Mass flow and diffusion of nutrients to a root with constant or zero-sink uptake 2. Zero-sink uptake. Soil Sci 157:171–175
Fiscus EL (1975) The interaction between osmotic and pressure-induced water flow in plant roots. Plant Physiol 59:1013–1020
Frensch J, Steudle E (1989) Axial and radial hydraulic resistance to roots of maize Zea mays L. Plant Physiol 91:719–726
Green SR, Kirkham MB, Clothier BE (2006) Root uptake and transpiration: from measurements and models to sustainable irrigation. Agric Water Manage 86:165–176
Hellmers H, Horton JS, Juhren G, O’Keefe J (1955) Root systems of some chaparral plants in southern California. Ecology 36(4):667–678
Hinsinger P, Gobran GR, Gregory PJ, Wenzel WW (2005) Rhizosphere geometry and heterogeneity arising from root-mediated physical and chemical processes. New Phytol 168:293–303
Javaux M, Schröder T, Vanderborght J, Vereecken H (2008) Use of a three-dimensional detailed modeling approach for predicting root water uptake. Vadose Zone J 7:1079–1088
Linton MJ, Nobel PS (2001) Hydraulic conductivity, xylem cavitation, and water potential for succulent leaves of Agave deserti and Agave tequilana. J Plant Sci 162:747–754
Lopez FB, Nobel PS (1991) Root hydraulic conductivity of two cactus species in relation to root age, temperature, and soil water status. J Exp Botany 42:143–149
Mapfumo E, Aspinall D, Hancock TW (1994) Growth and development of roots of grapevine (Vitis vinifera L.) in relation to water uptake from soil. Ann Botany 74(1):75–85
Metselaar K, de Jong-van-Lier Q (2007) The shape of the transpiration reduction function under plant water stress. Vadose Zone J 6:124–139
Miller EC (1916) Comparative study of the root systems and leaf areas of corn and the sorghums. J Agric Res 6(9):311–331
Miller DM (1985) Studies of root function in Zea mays. Plant Physiol 77:168–174
Passioura JB (1988) Water transport in and to roots. Ann Rev Plant Physiol Plant Mol Biol 39:245–265
Philip JR (1968) Steady infiltration from buried point sources and spherical cavities. Water Resour Res 4(5):1039–1047
Philip JR (1989) The scattering analog for infiltration in porous media. Rev Geophys 27(4):431–448
Pinder GF, Celia MA (2006) Subsurface hydrology. Wiley, New York
Raats PAC (2007) Uptake of water from soils by plant roots. Transp Porous Media 68:5–28
Rand RH (1983) Fluid mechanics of green plants. Ann Rev Fluid Mech 15:29–45
Roose T, Fowler AC (2004a) A mathematical model for water and nutrient uptake by plant root systems. J Theor Biol 228:173–184
Roose T, Fowler AC (2004b) A model for water uptake by plant roots. J Theor Biol 228:155–171
Schneider CL, Attinger S, Delfs J-O, Hildebrandt A (2010) Implementing small scale processes at the soil-plant interface—the role of root architectures for calculating root water uptake profiles. Hydrol Earth Syst Sci 14:279–289
Severino G, Indelman P (2004) Analytical solutions for reactive solute transport under an infiltration–redistribution cycle. J Contam Hydrol 70:89–115
Severino G, Monetti VM, Santini A, Toraldo G (2006) Unsaturated transport with linear kinetic sorption under unsteady vertical flow. Transp Porous Media 63:147–174
Smith DM, Meinzer FC, Allen SJ (1996) Measurement of sap flow in plant stems. J Exp Bot 47(305):1833–1844
Sperry JS, Adler FR, Campbell GS, Comstock JP (1998) Limitation of plant water use by rhizosphere and xylem conductance: results from a model. Plant Cell Environ 21(4):347–359
Sperry JS, Hacke UG, Oren R, Comstock JP (2002) Water deficits and hydraulic limits to leaf water supply. Plant Cell Environ 25:251–263
Steppe K, De Pauw D, Lemeur R, Vanrolleghem PA (2005) A mathematical model linking tree sap flow dynamics to daily stem diameter fluctuations and radial stem growth. Tree Physiol 26:257–273
Steudle E (2000) Water uptake by roots: effects of water deficit. J Exp Botany 51:1531–1542
Tartakovsky DM, Guadagnini A, Riva M (2003a) Stochastic averaging of nonlinear flows in heterogeneous porous media. J Fluid Mech 492:47–62
Tartakovsky DM, Lu Z, Guadagnini A, Tartakovsky AM (2003b) Unsaturated flow in heterogeneous soils with spatially distributed uncertain hydraulic parameters. J Hydrol 275(3–4):182–193
Tartakovsky AM, Garcia-Naranjo L, Tartakovsky DM (2004) Transient flow in a heterogeneous vadose zone with uncertain parameters. Vadose Zone J 3(1):154–163
Tsuda M, Tyree MT (2000) Plant hydraulic conductance measured by the high pressure flow meter in crop plants. J Exp Botany 345:823–828
van Dyke MD (1975) Perturbation methods in fluid mechanics. Academic Press, New York
Verhulst F (2005) Methods and applications of singular perturbation. Springer, New York
Wallach R (1998) A small perturbations solution for nonequilibrium chemical transport through soils with relatively high desorption rate. Water Resour Res 34:149–154
Warrick AW (2003) Soil water dynamics. Oxford University Press, Oxford
Weatherley PE (1982) Water uptake and flow in roots. In: Lange OL, Nobel PS, Osmond CB, Ziegler H (eds) Physiological plant ecology—II water relations and carbon assimilation. Springer, New York, pp 79–109
Acknowledgments
This research was supported in part by the National Science Foundation award EAR-1246315 and by the Computational Mathematics Program of the Air Force Office of Scientific Research. The first author acknowledges support from “Programma di scambi internazionali per mobilitá di breve durata” (Naples University, Italy), “OECD Cooperative Research Programme: Biological Resource Management for Sustainable Agricultural Systems” (Contract No. JA00073336), and PRIN project “I paesaggi tradizionali dell’agricoltura italiana: definizione di un modello interpretativo multidisciplinare e multiscala finalizzato alla pianificazione e alla gestione” (Contract No. 2010LE4NBM_007). The first author thanks Prof. Gerardo Toraldo (Naples University) for promoting his visit to University of California, San Diego; and Dr. Peng Wang for his kind hospitality.
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Severino, G., Tartakovsky, D.M. A boundary-layer solution for flow at the soil-root interface. J. Math. Biol. 70, 1645–1668 (2015). https://doi.org/10.1007/s00285-014-0813-8
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DOI: https://doi.org/10.1007/s00285-014-0813-8