ATP Concentration and Soil Respiration at Reduced Water Potentials in Arid Soils1
- W. G. Knight and
- J. Skujins2
Adenosine triphosphate (ATP) concentrations and soil respiration rates of two arid and one subalpine forest soil were evaluated as a function of water potential (ψw) in the range −2 to −100 bars. Water potential was determined by thermocouple psychrometry, CO2 release from soil by titrimetry; ATP was extracted from soil with cold sulfuric acid and assayed by luciferin-luciferase methology. ATP concentrations increased in the ψw range −2 to −20 bars in the arid soils and was negatively correlated (r2 = 0.92) with exponential decreases in respiration rates for the same ψw range. In the subalpine forest soil, the highest ATP concentration was at the highest measured water potential (−2 bars) and decreased with decreasing respiration rates (r2 = 0.93) and decreasing ψw values. It was concluded that the soil microflora may exhibit diverse physiological responses to water and, consequently, to available carbon-source induced stresses in soils from environmentally different areas.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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