Relationship of Reduction Intensity with Root Porosity and Radial Oxygen Loss

2 Relationship of Reduction Intensity with Root Porosity and Radial Oxygen Loss 

FIGURE 7.32 Root elongation of Spartina patens in response to changing soil redox potential (Eh), (a) Response to high Eh (aerobic) followed by low Eh (anaerobic) conditions, (b) Reverse procedure. (Modified from Pezeshki and DeLaune, 1990.) 

FIGURE 7.33 Recovery of root elongation in Spartina patens after an increase in soil redox potential (Eh) to +500 mV. The increase in Eh followed anaerobic conditions in which soil Eh was reduced for 5 days to a range of -180 to -200 mV (closed circles), -100 to 150 mV (x s), and 0 to -100 mV (open circles). (Erom Pezeshki and DeLaune, 1990.) 

FIGURE 7.34 Relationship between root elongation of Spartina patens and soil redox potential (Eh). (Redrawn from Pezeshki and DeLaune, 1990.) 

In Taxodium distichum, a significant increase in root porosity and ROL was noted at Eh intensity of -240 to -260 mV in root medinm (Kludze et al., 1994a, 1994b). ROL increased from 12.7 in control treatments to 42.3 mmol O2 day Similarly, root airspace increased from 13.3 to 41.4% in response to the intensity of rednction. In 0. saliva (rice), ROL increased in response to a drop 

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