John Sperry


Department of Biology
257 South 1400 East
University of Utah
Salt Lake City, UT 84112

phone: 801 585-0379
fax: 801 581-4668

j dot sperry at utah dot edu




John Sperry



With the advantage of 20/20 hindsight I can trace my fascination with plants and water transport back to kindergarten. Of course I was also obsessed with being a truck driver. But I did draw lots of trees and enjoyed watching our teacher demonstrate the ascent of food coloring in the transpiration stream of a celery stalk. I exited the other end of the educational pipeline with a PhD under the sap transport expert Martin Zimmermann. I learned still more during a post-doctoral stint with another master of plant water relations, Melvin Tyree. Since joining the Biology Department of the University of Utah in 1989 I have continued research in plant hydraulics. Projects past, present, and future range in scale from the flow resistance past a scalariform perforation plate to drought-induced dieback of pinyon pine in the American southwest. Fields of study span the spectrum from physiology and biomechanics, through ecology and evolution, and ecosystems. Projects include learning what makes plant xylem cavitate under stress, mechanisms of xylem embolism repair, allometric and process models of the soil-plant-atmosphere continuum, evolution of xylem function, and the linkage between plant water use and ecosystem productivity. Methods and approaches include multiple vulnerability curve and hydraulic conductivity techniques, sap flux, MRI, single-vessel hydraulics, lots of microscopy and quantitative anatomy, and mathematical modeling. Study organisms and sites range from woody plants of the Wasatch Mountains of Utah, Shrubs from the North American deserts, Conifer and angiosperm trees of the eastern deciduous and boreal forests, basal angiosperms from new and old world tropics, Lianas, Gnetophytes, and a variety of herbaceous crop plants including rice and soybean.