March 2016 - IRIS v4.0 Released (current version)
Immaterial change. Metric name and definition modified to increase generalization and clarity.
March 2014 - IRIS v3.0 Released
Immaterial change. Minor revision to definition language for clarity.
February 2011 - IRIS v2.1 Released
September 2010 - IRIS v2.0 Released
September 2009 - IRIS v1.0 Released
New metric. Trees Planted: Native Species (PI3848) developed via Original IRIS Working Group.