Huggett, Brett A. , Holbrook, Noel , Dietterich, Lee , Onstad, James .
Calcium deficiency and whole plant water relations in sugar maple (Acer saccharum Marsh.).
There is strong evidence that various anthropogenic factors, including nitrogen saturation, forest harvesting, changing climatic conditions, soil aluminum (Al) mobilization, acid loading, and declines in atmospheric base cation deposition, contribute to the well documented depletion of calcium (Ca) from forest ecosystems in the Northeastern United States and Canada. Although decreased availability of this biologically essential element has been considered a causal factor in the decline in health of forested ecosystems, little is known if, and by what underlying mechanisms, Ca depletion influences the water relations of plants. We tested the hypothesis that Ca-related reductions in cell growth and stabilization compromise the biomechanical properties and function of conductive tissue. The proven correlation between cavitation resistance and wood density and structure provided a potential mechanism linking xylem function with the availability of Ca. Surveying forest-grown sugar maples (Acer saccharum Marsh.) from a long-term replicated Ca-manipulation study at the Hubbard Brook Experimental Forest, NH, USA, we found no significant impact of Ca-deficiency on wood density, stem hydraulic conductance, or vulnerability to cavitation. Furthermore, no difference in leaf water potential was detected between treatment trees. Additional studies will be conducted to examine how anthropogenic alterations in calcium availability might impact the growth of sugar maple via impacts on root hydraulic conductivity and stomatal regulation.
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1 - Harvard University, Organismic and Evolutionary Biology, Biolabs Rm 3107, 16 Divinity Ave, Cambridge, Ma, 02138
2 - Harvard University, Department of Organismic and Evolutionary Biology, 16 Divinity Ave, Cambridge, MA, 02138, USA
Presentation Type: Poster:Posters for BSA Sections
Location: Event Tent/Cliff Lodge
Date: Tuesday, July 28th, 2009
Time: 5:30 PM