Conceptually Simple - Easy to Use - Easy to Analyze
What is IRIS and How Does it Work?
1. IRIS - Indicator of Reduction In Soils
2. PVC devices coated with Fe (or Mn) oxides
2. PVC devices coated with Fe (or Mn) oxides
IRIS – is an acronym for Indicator of Reduction In Soils. “Reduction” means electrochemical reduction caused by the activity of soil microbes under wetland conditions. Reducing conditions contribute to important wetland ecosystem functions.
2. PVC devices coated with Fe (or Mn) oxides
2. PVC devices coated with Fe (or Mn) oxides
2. PVC devices coated with Fe (or Mn) oxides
IRIS are PVC devices (films or tubes) coated with Fe (or Mn) oxides that can be installed into a saturated soil to measure or document reduction.
3. Microbes Consume Dissolved Oxygen
2. PVC devices coated with Fe (or Mn) oxides
3. Microbes Consume Dissolved Oxygen
In wetland soils, microbes consume dissolved oxygen as an “electron acceptor” while decomposing organic matter. When soils are saturated, this can result in the soil becoming anaerobic (reducing).
4. Microbes use Fe and Mn Oxides
6. Stripping of Coatings Demonstrates Reduction
3. Microbes Consume Dissolved Oxygen
When dissolved oxygen is depleted in soils (when soils are anaerobic/reduced), microbes will used other compounds for “electron acceptors” such as Fe oxides or Mn oxides.
5. IRIS Installed in the Soil
6. Stripping of Coatings Demonstrates Reduction
6. Stripping of Coatings Demonstrates Reduction
When IRIS are installed in the soil, microbes can utilize the oxide coatings on IRIS (as electron acceptors), and as they do, the coatings are altered, and become dissolved, and strip off the IRIS device.
6. Stripping of Coatings Demonstrates Reduction
6. Stripping of Coatings Demonstrates Reduction
6. Stripping of Coatings Demonstrates Reduction
Therefore, the stripping or removal of (Fe or Mn) oxide coatings from IRIS, demonstrates that the soil has become anaerobic or reducing, and is functioning like a true wetland soil.