Freezing-induced xylem cavitation and the northern limit of @Larrea tridentata Export

@article{PockmanSperry_97, abstract = {We investigated the occurrence of freezing-induced cavitation in the evergreen desert shrub Larrea tridentata and compared it to co-occurring, winter-deciduous Prosopis velutina. Field measurements indicated that xylem sap in L. tridentata froze at temperatures below c. ?5C, and that this caused no measurable cavitation for minimum temperatures above ?7C. During the same period P. velutina cavitated almost completely. In the laboratory, we cooled stems of L. tridentata to temperatures ranging from ?5 to ?20C, held them at temperature for 1 or 12 h, thawed the stems at a constant rate and measured cavitation by the decrease in hydraulic conductivity of stem segments. As observed in the field, freezing exotherms occurred at temperatures between ?6.5 and ?9C and as long as temperatures were held above ?11C there was no change in hydraulic conductivity after thawing. However, when stems were cooled to between ?11C and ?20C, stem hydraulic conductivity decreased linearly with minimum temperature. Minimum temperatures between ?16 and ?20C were sufficient to completely eliminate hydraulic conductance. Record (>20 year) minimum isotherms in this same range of temperatures corresponded closely with the northern limit of L. tridentata in the Mojave and Sonoran deserts.}, author = {Pockman, W. T. and Sperry, J. S.}, citeulike-article-id = {1523891}, citeulike-linkout-0 = {http://www.springerlink.com/index/NJ2567XT89JB47N1.pdf http://www.biology.utah.edu/sperry/pubs/Oecologia97.pdf}, journal = {Oecologia}, keywords = {bibtex-import, dependance, diameter, distribution, embolism, limits, recovery, temperature}, pages = {19--27}, posted-at = {2007-07-31 06:53:37}, priority = {5}, title = {Freezing-induced xylem cavitation and the northern limit of @Larrea tridentata}, url = {http://www.springerlink.com/index/NJ2567XT89JB47N1.pdf http://www.biology.utah.edu/sperry/pubs/Oecologia97.pdf}, volume = {109}, year = {1997} }

TY - JOUR ID - PockmanSperry_97 L3 - citeulike-article-id:1523891 N2 - We investigated the occurrence of freezing-induced cavitation in the evergreen desert shrub Larrea tridentata and compared it to co-occurring, winter-deciduous Prosopis velutina. Field measurements indicated that xylem sap in L. tridentata froze at temperatures below c. ?5C, and that this caused no measurable cavitation for minimum temperatures above ?7C. During the same period P. velutina cavitated almost completely. In the laboratory, we cooled stems of L. tridentata to temperatures ranging from ?5 to ?20C, held them at temperature for 1 or 12 h, thawed the stems at a constant rate and measured cavitation by the decrease in hydraulic conductivity of stem segments. As observed in the field, freezing exotherms occurred at temperatures between ?6.5 and ?9C and as long as temperatures were held above ?11C there was no change in hydraulic conductivity after thawing. However, when stems were cooled to between ?11C and ?20C, stem hydraulic conductivity decreased linearly with minimum temperature. Minimum temperatures between ?16 and ?20C were sufficient to completely eliminate hydraulic conductance. Record (>20 year) minimum isotherms in this same range of temperatures corresponded closely with the northern limit of L. tridentata in the Mojave and Sonoran deserts. JF - Oecologia EP - 27 TI - Freezing-induced xylem cavitation and the northern limit of @Larrea tridentata VL - 109 SP - 19 KW - bibtex-import KW - dependance KW - diameter KW - distribution KW - embolism KW - limits KW - recovery KW - temperature AU - Pockman, WT AU - Sperry, JS PY - 1997/// UR - http://www.springerlink.com/index/NJ2567XT89JB47N1.pdf http://www.biology.utah.edu/sperry/pubs/Oecologia97.pdf ER -