ADAPTIVE VARIATION IN THE VULNERABILITY OF WOODY PLANTS TO XYLEM CAVITATION

The ability of plants to supply water to their leaves is intimately associated with survival. Water supply to leaves depends on maintaining an intact water column in the xylem from the roots to shoots. Because this hydraulic pathway is under tension, it is vulnerable to breakage through the induction of air emboli (cavitation). Although the physiological benefit of resistance to water-stress-induced xylem cavitation for desiccation tolerance is clear, there is considerable interspecific variation within and across climates. To understand the adaptive significance of this variation and the potential trade-off with water transport, we compiled a database of 167 species from 50 seed plant families and examined…

• NS
  National Science Foundation
• UD
  U.S. Department of Energy