UW bulletin details pre- and post-fire soils research

Research may benefit the area impacted by the Roosevelt Fire burned earlier this year.

A new University of Wyoming

bulletin contributes to the growing

knowledge base of ecosystem recovery following

high-intensity forest fires.

The publication details an ongoing study

examining ecological impacts of the 2012

Arapaho Fire, which burned nearly 100,000

acres in the north Laramie Mountains of

southeast Wyoming, including the UWowned

Rogers Research Site.

Preliminary results indicate that marked

soil chemical and biotic changes occurred at

the 320-acre site following the fire. They are

presented in RRS Bulletin 7, “Pre- and Postfire

Soil Comparisons, Rogers Research Site,

North Laramie Mountains, Wyoming.”

“As wildfires are becoming more frequent

across the United States, it warrants solid

knowledge about the consequences of these

events for the recovery of ecosystems,” said

co-author Linda van Diepen, an assistant

professor of soil microbial ecology in the

Department of Ecosystem Science and Management

within the College of Agriculture

and Natural Resources.

“Through comparison of soil conditions

pre- and post-fire, we are better able to understand

the impacts of high-severity fires

such as the Arapaho, which, in turn, helps us

in measuring the recovery of the ecosystem

back to its original state,” van Diepen said.

In spring 2012, UW graduate student

Claire Wilkin and her faculty co-advisor,

Professor Steve Williams, established eight

monitoring plots at RRS to document soils,

plant distribution, water sources, topographic

features and belowground biota.

Fortuitously, they collected soil samples

within the plots just weeks prior to the lightning-

caused Arapaho Fire, which started

during an extreme drought. The fire burned

across the sites and neighboring lands in

early July, reaching temperatures estimated

at nearly 900 degrees Fahrenheit.

With this baseline information in hand,

bulletin coauthors Wilkin and Williams refocused

their study on pre- and post-fire soil


“As such, understanding how fire impacts

important nutrients in the soil is paramount

to understanding ponderosa pine ecosystems,

including the one at RRS and surrounding

lands,” Williams said.

After observing noticeable changes in soil

chemical and biotic changes, Williams and

Wilkin became interested in exploring the

subsequent effect these changes might have

on the soil microbial communities, which

will be detailed in the nearly completed RRS

Bulletin 8.

Since Wilkin’s graduation and Williams’

retirement, a team of UW faculty and students

led by van Diepen have continued the

soil studies and related post-fire ponderosa

pine research at RRS.

“The research includes soil chemistry and

biology, including carbon and nitrogen budgets,

and microbial community composition,

which are important factors determining nutrient

availability to the recovering vegetation,”

van Diepen said. “We are also studying

the recovery of ponderosa pine, grasses, forbs

and shrubs, in addition to measuring how invasive

plants are responding to the fire.”

The 320-acre RRS was bequeathed to UW

in 2002 by Col. William C. Rogers, who purchased

the land shortly after retiring from the

U.S. Army. He stated in his will that research

at the site should focus, in part, on the improvement

of forestry and wildlife resources.

“Understanding the responses of soil to

wildfire and how it is related to vegetation

growth after fire will aid land managers in

determining priorities for enhancing forest

recovery to provide habitat for wildlife,” van

Diepen said.

Other authors of Bulletin 7 include Larry

Munn, professor emeritus in the Department

of Ecosystem Science and Management; Michael

Urynowicz, professor in the Department

of Civil and Architectural Engineering;

and Robert Waggener, editor for the Wyoming

Agricultural Experiment Station.

WAES and one of its research stations, the

James C. Hageman Sustainable Agriculture

Research and Extension Center near Lingle,

manage RRS. They are within the College of

Agriculture and Natural Resources.

The first seven bulletins detailing research,

extension, teaching and other activities

at RRS are posted on the SAREC website

at http://bit.ly/RogersResearchSite.


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