Home

Curriculum and Research Vita

 Courses  

Geography Home


 
Wisconsin Oak Savanna Fire History


Joy Wolf, Ph.D.
University of Wisconsin - Parkside


 

Fires swept through Wisconsin oak savanna systems and played an 
important role in maintaining the community structure and diversity. 		 
 
Oak savanna fires:
   Create sun space
   Enrich the soil
   Remove invasive species

...while larger oaks survive the fires.

Bur oak (Quercus macrocarpa) has thick corky bark that is resistant to fire. 		          
 

Fire history records are limited in Midwestern ecosystems, yet are essential toward

1.   understanding oak dynamics
2.  developing / implementing management programs for restoration and preservation.  
3.  developing a policy of prescribed burns in remnant patches

 

  
In this research, we determine the fire history for the past 200 years 
using dendrochronology.  Dendrochronology is the study of patterns 
in tree rings to determine ecosystem dynamics, disturbance regimes, 
land use changes, and climatic fluctuations.

My students involved in this research learn about fire and
vegetation dynamics in the oak savanna, the lab techniques for 
dendrochronology, and the human element in ecosystem processes. 
We examined land use records, aerial photos, vegetation maps, 
and climate data to correlate with fire dates and the tree ring record.

 

 
Here's what we're doing!
 

The study site is within a landscape of fragmented oak savanna and oak woodland.      Photo:  Pete Schwalbe
   

In October 2000, the area was cut for development.    

I acquired the cross-sections in Feb 2001

The University provided a space for the 
wood to dry slowly .
Many students helped in sanding the wood.

Inspecting the rings for marker years & fires.
Cross sections allowed us to follow the
wood for false rings.

Skeleton plots show marker years & fire dates (2 plots from different radii)

FHX2 Fire Frequency output
 

Fire seasonality:  most fires occurred during the dormant season.

nThe age structure was bimodal
n half germinated between  1804-1815
n half germinated between  1847-1862

 
The marker and fire years were correlated with with local climate data.
 

After fire years were dated, land use 
history was used to explain the fire frequency.
Land managers can use this data to 
restore an adjacent oak savanna. 
 
   

 


Photo:  Pete Schwalbe
This oak savanna has important cultural artifacts within it, including the Potawatami Trail  and campground site (shown in this image)
 
Acknowledgements:

Field and Lab Assistants:
Robert Bruno,  Cindy Eckert, Matt Liesch,  Ron Londre,  Donna Minkley,  Rebecca Sladek, and Michael Stanton


 L-R:  me, Ron, Donna, Becky.  Not pictured:  Robert Bruno and Matt Liesch.
 

Also Thanks To:
University of Wisconsin - Parkside - Undergraduate Research and Equipment Grant

Marty Johnson, Wisconsin DNR - Obtaining specimens
Richard Oscarson - Obtaining specimens
Kathy Chybowski - Historical Data
Pete Schwalbe - Historical Data, Photos

 

The results can be found in:

American Midland Naturalist

 

And presented at:
* Ecological Society of America 2001 Meeting, Madison, Wisconsin
* Association for American Geographers 2002 Meeting, New Orleans, LA
* International Biogeography Society 2002 Meeting, Mesquite, NV
* International Association for Landscape Ecology 2002 Mtg, Banff, Canada

Last updated: 03/02/2008