Friday, August 6, 2010 - 8:40 AM

COS 114-3: Comparisons in morphology, anatomy, and water relations of three evergreen shrubs in an eastern temperate forest understory

Sheri A. Shiflett and Donald R. Young. Virginia Commonwealth University

Background/Question/Methods

Morphology, anatomy, and water storage of three evergreen woody shrubs were characterized in a temperate forest understory environment to understand the physiological strategies for survival in the understory.  The three species represent different families and include Morella cerifera (Myricaceae), Ilex opaca (Aquifoliaceae), and Kalmia latifolia (Ericaceae).  Differences in wood anatomy were related to water relations parameters.  Wood density, stem and leaf capacitance, relative water content, specific leaf area, stomatal density, stomatal size, stomatal conductance, and soil moisture were measured. 

Results/Conclusions

Interspecific differences in anatomy reflect differences in capacitance and hydraulic conductivity among the three evergreens and may be indicative of variable adaptive strategies for survival in a light limited and periodically water limited forest understory. There were differences in stomatal distribution and specific leaf area among species, but there appeared to be convergence with regard to wood density (~0.55 g/cm3) and branching patterns as indicated by bifurcation ratios (~3.23).  Differences among species may be related to position relative to overstory canopy gaps.  Understanding the physiological strategies of these species will lead to an understanding of which temperate species would be able to tolerate predicted effects of increasing temperatures and shifts in precipitation predicted with climate change scenarios.