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Water uptake and storage by rhizosheaths of Oryzopsis hymenoides: a numerical simulation
Author(s) -
Bristow Caryn E.,
Campbell G. S.,
Wullstein L. H.,
Neilson R.
Publication year - 1985
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1985.tb02387.x
Subject(s) - water flow , perennial plant , absorption of water , water storage , rhizosphere , environmental science , flow resistance , flow (mathematics) , botany , agronomy , hydrology (agriculture) , biology , soil science , geology , mechanics , geotechnical engineering , physics , genetics , geomorphology , bacteria , inlet
Rhizosheaths (sheaths of sand grains that form around the roots of some grasses) are common in perennial grasses that colonise sandy substrates. It has been hypothesised that rhizosheaths increase water availability by increasing the efficiency of water absorption. Others have suggested that rhizosheaths act as storage reservoirs for water. In either case rhizosheaths undoubtedly play an important role in the water relations of these grasses. In an attempt to evaluate the main function of rhizosheaths, we developed a finite element cylindrical water flow model which enabled us to simulate water uptake by Oryzopsis hymenoides (Roem, and Shult.) Ricker. This model allowed us to estimate total water uptake by root systems with and without rhizosheaths and to compare these values to the extra water stored within the rhizosheath. The results of this study suggest that the presence of rhizosheaths is more important in reducing the total resistance to water flow within the rhizosphere than in enhancing water storage.