Transpiration Stream of Desert Species: Resistances and Capacitances for a C3, a C4, and a CAM Plant Export

@article{citeulike:2873240, abstract = {Transpiration rates and water potentials of three sympatric desert perennials, a C3 subshrub (Encelia farinosa), a C4 bunchgrass (Hilaria rigida), and a CAM succulent (Agave deserti), were analysed using an electrical circuit analogue that included resistances and capacitances for the leaves, stems, and roots. The water storage capability of the organs differed considerably, capacitance ranging over 1000-fold from the thin leaves of H, rigida to the massive leaves of A. deserti, although the capacitance per unit volume varied only 1.9-fold. The diurnal changes in water storage could support maximum transpiration rates of H. rigida for 4 min, E. farinosa for 7 min, and A. deserti for 16 h. The time constant for equilibration of water from storage to the xylem ranged from 29 s for roots of H. rigida to 52 min for leaves of A. deserti. Resistances for such movement were relatively low for the succulent leaves of A. deserti and were up to about 50-fold higher for the three organs of E. farinosa. Xylem resistances calculated using the Hagen-Poiseuille law and measured xylem dimensions were 2.1- to 2.1-fold lower than resistances estimated from observed water potential drops, a discrepancy which is in agreement with other published data. Contrary to data on other plants, the xylem resistances in the roots and leaves of E. farinosa and H. rigida averaged only 15\% of the stem xylem resistance. 10.1093/jxb/34.10.1379}, author = {Nobel, Park S. and Jordan, Peter W.}, citeulike-article-id = {2873240}, citeulike-linkout-0 = {http://dx.doi.org/10.1093/jxb/34.10.1379}, citeulike-linkout-1 = {http://jxb.oxfordjournals.org/cgi/content/abstract/34/10/1379}, day = {1}, doi = {10.1093/jxb/34.10.1379}, journal = {J. Exp. Bot.}, keywords = {diameter, grass, hydraulics, leaf}, month = {October}, number = {10}, pages = {1379--1391}, posted-at = {2008-06-08 08:50:58}, priority = {2}, title = {Transpiration Stream of Desert Species: Resistances and Capacitances for a C3, a C4, and a CAM Plant}, url = {http://dx.doi.org/10.1093/jxb/34.10.1379}, volume = {34}, year = {1983} }

TY - JOUR ID - citeulike:2873240 L3 - citeulike-article-id:2873240 N2 - Transpiration rates and water potentials of three sympatric desert perennials, a C3 subshrub (Encelia farinosa), a C4 bunchgrass (Hilaria rigida), and a CAM succulent (Agave deserti), were analysed using an electrical circuit analogue that included resistances and capacitances for the leaves, stems, and roots. The water storage capability of the organs differed considerably, capacitance ranging over 1000-fold from the thin leaves of H, rigida to the massive leaves of A. deserti, although the capacitance per unit volume varied only 1.9-fold. The diurnal changes in water storage could support maximum transpiration rates of H. rigida for 4 min, E. farinosa for 7 min, and A. deserti for 16 h. The time constant for equilibration of water from storage to the xylem ranged from 29 s for roots of H. rigida to 52 min for leaves of A. deserti. Resistances for such movement were relatively low for the succulent leaves of A. deserti and were up to about 50-fold higher for the three organs of E. farinosa. Xylem resistances calculated using the Hagen-Poiseuille law and measured xylem dimensions were 2.1- to 2.1-fold lower than resistances estimated from observed water potential drops, a discrepancy which is in agreement with other published data. Contrary to data on other plants, the xylem resistances in the roots and leaves of E. farinosa and H. rigida averaged only 15% of the stem xylem resistance. 10.1093/jxb/34.10.1379 IS - 10 JF - J. Exp. Bot. EP - 1391 TI - Transpiration Stream of Desert Species: Resistances and Capacitances for a C3, a C4, and a CAM Plant VL - 34 SP - 1379 KW - diameter KW - grass KW - hydraulics KW - leaf AU - Nobel, Park AU - Jordan, Peter PY - 1983/10/01/ UR - http://dx.doi.org/10.1093/jxb/34.10.1379 ER -