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Ducks fly over rough water on the Bay of Green Bay.

2009 Cofrin Student Symposium

Wednesday, February 25, 2009
1:30-4:00 pm 
1965 Room: University Union

Schedule of Presentations:

1:30--Introduction and Welcome by Cofrin Biodiversity Center Director Dr. Robert Howe

1:40--Linda Filo, (Prof. Amy Wolf and Robert Howe)

Mapping and assessing campus populations of Phragmites australis.

2:05--Presentation of Sager Scholarships  to Brittany Brodziski for her paper entitled “An analysis of the presence of diethyl and dibutyl phthalate in scented oil air fresheners.” (Dr. John Lyon) and to Adam Snippen for his paper “Characteristics and microbial respiration analysis of a southern boreal forest in Door County, Wisconsin.” (Dr. Amy Wolf).

2:25--Matthew Flentje (Faculty advisor: Robert Howe)

“An owl survey of UWGB natural areas.”

2:50--Ethan Kaiser (Faculty advisors: Amy Wolf and Robert Howe)

“Earthworm abundance in annually burned vs. unburned grasslands in the UW-Green Bay Cofrin Arboretum.”

3:15--Meagan Davis (Faculty advisor: Robert Howe)

“Research on Cliff Swallows in the Cofrin Arboretum.”

3:40--Closing Remarks by Dr. Howe

Presentation Abstracts

Linda Filo, (Prof. Amy Wolf and Robert Howe) “The ecological effects of timing in control of Phragmites australis at Point au Sauble Nature Preserve in Brown County, Wisconsin.”.

The invasion of Phragmites into new areas can displace native vegetation and destroy habitat for invertebrates, fish, and birds.  As a result, control of Phragmites has become a priority for resource managers in many areas.  Common control methods include spraying herbicide (glyphosate or imazapyr), mowing and spraying, and burning.  Despite the widespread use of these control techniques, published accounts on the effects of these treatments are limited.  Repeated use of these control methods may be costly, time consuming, or even detrimental to other species. Evaluating the various approaches of control and continuing the search for improvements in the way Phragmites is managed is necessary to conserving natural areas. In partnership with the Green Bay U.S. Fish and Wildlife Service, this projectanalyzed the effect of the timing of mowing pretreatments on the ecology of a Phragmites dominated wetland.  Our goal is to assess whether different mowing schedules (early vs. late) affect the success of herbicide treatment in controlling Phragmites and whether timing of treatment affects the capacity of native species to recolonize the wetland.


Matthew Flentje (Faculty advisor: Robert Howe) “An owl survey of UWGB natural areas.”

Owls are usually poorly known, and we tend not to study them as much as their diurnal counterparts.  Even so, there has been a website founded for a statewide owl survey. In 1994, another student named Michael Jaccard did an owl survey and found only two different species, the Great Horned owl and the Barred Owl. We believe that two more species of owls could also be found in an owl survey, the Saw-whet Owl and the Eastern Screech Owl.  I believe that a more through survey of owl populations in the area would be beneficial to the natural areas that UWGB has.  With a more accurate survey, perhaps we can understand more on their migration and nesting behaviors that will perhaps draw more potential bird watchers and researchers into the area.The purpose of this project was to document and record the owl occurrences in the natural areas of Green Bay.  I used standardized playback surveys and will be monitoring in the early spring to fall, and all the routes will be mapped using standard GIS.


CEthan Kaiser (Faculty advisors: Amy Wolf and Robert Howe) “Earthworm abundance in annually burned vs. unburned grasslands in the UW-Green Bay Cofrin Arboretum.”

Very few studies have rigorously examined the effects of burning on invasive earthworms.  Burning and its accompanying impact on leaf litter and microhabitats has a potentially profound effect on surface-dwelling and even shallow-dwelling earthworms.  compared earthworm abundance and diversity at three types of grasslands on the UW-Green Bay campus: 1) Planted native grassland that is burned annually, 2) planted prairie grassland that is unburned, and 3) unburned grassland dominated by non-native species.  The planted native grasslands are part of the Keith White Prairie in UW-Green Bay’s Cofrin Arboretum. I tested whether earthworm abundance, species richness, and biomass differed among plots from annually burned native grassland, unburned native grassland, and unburned non-native grasslands in the Cofrin Arboretum. 

Meagan Davis (Faculty advisor: Robert Howe) “Research on Cliff Swallows in the Cofrin Arboretum.”

The Cliff Swallow colony at the University of Wisconsin-Green Bay has been studied since 1997 by UWGB researchers Gregory and Jennifer Davis. Cliff Swallows have nested on all the large buildings on the UWGB campus. The swallows feed on flying insects over old-field habitat areas on and near the campus.  House Sparrows (Passer domesticus) compete for Cliff Swallow nests.  Davis and Davis (2002) noted that House Sparrows often usurp Cliff Swallow nests and destroy swallow eggs, young, and juveniles. I was able to document the current status of Cliff Swallows on the UW-Green Bay campus and Cofrin Arboretum, I identified critical feeding areas and sources of nest-building materials, and described important interactions between the campus population and other species (including humans).   The project will help determine the effect, if any, of human activity near nesting Cliff Swallows.