Developmental and Structural Section
Duarte, David , Bobich, Edward , Pak, Sarah , Pham, Shawn , Utsumi, Yasuhiro , Ewers, Frank .
Seasonal changes in the vessel anatomy of adults and resprouts of California black walnut trees following wildfire.
Following a wildfire at Bonelli Park in San Dimas, CA, unburned adult trees and new growth resprouts of Juglans californica S. Watson were examined to determine the anatomical basis for seasonal variation in hydraulic conductivity and mechanical flexibility and strength. Differences between growth forms were also considered. Stems from nine individuals per adult and resprout growth forms were sampled monthly from February through June of 2008. Stem samples were sectioned to analyze for variances in vessel diameter, hydraulicvessel diameter, vessel frequency, percent conductive, and percent vessel lumenarea. The results showed a significantly greater vessel frequency in adults than in resprouts with a decrease of frequency through the season. In addition, the vessel lumen areas tended to be greater in adults, whereas the mean and hydraulic vessel diameters tended to be greater in resprouts. Both growth forms demonstrated positive increases in percent conductive, percent vessellumen area, and hydraulic vessel diameter going from February through June. All the seasonal changes can be attributed to the production of a new xylem growth ring. The resprouts especially showed much larger mean and much larger hydraulic mean vessel diameters in the outer growth ring. In adults, vessel frequency and percent vessel lumen area were especially high in the outer growth ring. A separate study on these plants showed that hydraulic conductivity increased greatly between the months of April and Mayfor adults and resprouts, likely related to the production of the outer growth ring. Overall differences between growth forms in vessel diameter and frequency were correlated to higher mechanical strength (lower vessel frequency and percent vessel lumen area) and higher hydraulic conductivity (greater hydraulic diameter) in resprouts than in adult trees.
Log in to add this item to your schedule
1 - California State Polytechnic University, Biological Sciences, 3801 West Temple Aveneu, Pomona, CA, 91768, USA
2 - California State Polytechnic University, Pomona, 3801 W. Temple AVE, Pomona, CA, 91768, USA
3 - California State Polytechnic University, Pomona, Biological Sciences, 3801 West Temple Aveneu, Pomona, CA, 91768, USA
4 - Kyushu University, Tsubakuro 394, Sasaguri, Fukuoka, N/A, 811-2415, Japan
5 - California State Polytechnic University, Pomona, Department Of Plant Biology, 3801 West Temple Avenue, Pomona, CA, 91768, USA
Presentation Type: Poster:Posters for Sections
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM