CS17 Invasive Species
Date: Thursday, June 13, 2002
Time: 4:15:00 PM
Location: Sidney
 
MaricleBR, Washington State University, Pullman, WA, USA, bmaricle@mail.wsu.edu
Lee, R, W, Washington State University, Pullman, WA, USA, rlee@mail.wsu.edu
 
PHYSIOLOGICAL MECHANISMS OF HYPOXIA TOLERANCE IN INVASIVE SPARTINA CORDGRASS: THE SIGNIFICANCE OF AERENCHYMA DEVELOPMENT AND OXYGEN TRANSPORT
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Spartina alterniflora and S. anglica are estuarine cordgrasses that develop extensive aerenchyma systems to lower metabolic demands or supply submerged portions of the plant with atmospheric oxygen. These physiological benefits are crucial for growth in hypoxic sediments and therefore help make introduced Spartina formidable invasive species in West Coast estuaries. Aerenchyma formation and function were investigated in S. alterniflora and S. anglica maintained in greenhouse experiments under flooded and drained conditions. S. alterniflora plants developed additional aerenchyma to counter flooding, yet did not transport oxygen internally. S. anglica plants were able to transport substantial oxygen to their roots, despite forming only minimal aerenchyma. Removal of above-ground biomass by mowing is presently being used as a means of Spartina control. This treatment may prevent oxygen transport and render rhizomes anaerobic. Additional physiological experiments were conducted on plants from Skagit and Willapa Bay, WA to determine the effect of mowing treatment on rates of oxygen transport and anaerobic enzyme expression.