What is Ozone?

Ground-level ozone is an oxidant formed by the reaction of nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. Warm temperatures speed the reaction. Ozone can harm humans by injuring the respiratory system. It also can oxidize plant tissue. Monitors in the Four Corners Region show that in some places ozone levels are approaching the regulatory limit for human health. None of these monitors are located above 8,000 feet elevation, however, and it is possible that the most elevated ozone levels actually occur up in the mountains as upslope winds sweep NOx and VOCs toward the higher altitudes. (For example, the highest ozone level ever measured on Colorado's Western Slope was recorded on Aspen Mountain in the winter of 2007-2008). 

Read more about MSI's Air Quality Program

What is the Ozone Bio-Monitoring Project About?

In 2009 MSI, in partnership with the San Juan Public Lands Center and the Boyce Thompson Institute of Cornell University, conducted the first-ever survey of high-elevation plants for signs of injury caused by ozone in the San Juan Mountains. MSI and its interns not only conducted the study, but they also worked with a leading expert, Dr. Robert Kohut, in the ozone foliar injury field to provide training to land managers.  Four species (cutleaf coneflower, spreading dogbane, red elderberry and quaking aspen) were selected as bioindicator species for this study. One or more of these species was found on 45 sites in the vicinity of Durango, Silverton, and Bayfield during July and August 2009.

A type of unknown injury was found in one of the study species, but it was concluded, after much literature review and expert opinion, not be be caused by ozone. Read more in the report posted below.

Manual for Easy Indentification of Ozone Bioindicators (1.4 MB PDF)

Project Report (2.5 MB PDf)

Project Manager: Dr. Koren Nydick, MSI

Thanks to MSI's Collaborators who helped on the project:

Kelly Palmer, Sally Zwisler, and Laurie Swisher from the San Juan Public Lands Center provided input in designing the project. Dr. Robert Kohut, emeritus scientist with the Boyce Thompson Institute of Cornell University, provided training in identifying foliar ozone injury as well as expert opinion to determine whether or not observed foliar injury was caused by ozone. Beth Adams and Michael Freer, MSI summer interns from the University of Colorado Boulder and Fort Lewis College, respectively, conducted initial scouting activities. Sally Zwisler, a forester with the San Juan Public Lands Center performed a GIS mapping exercise to identify locations of likely study sites. Dr. Ross McCauley, assistant professor of Botany at Fort Lewis College, confirmed plant species identifications. Kelly Palmer and her hydrology crew at the San Juan Public Lands Center accompanied us to the field during training exercises. Aaron Kimple with MSI helped make the map in Figure 3 of the report.

Thanks to the project funder:

San Juan Public Lands Center - Bureau of Land Management