Date of Award


Degree Type


Degree Name


Degree Program

Earth and Environmental Sciences


Earth and Environmental Sciences

Major Professor

Kulp, Mark

Second Advisor

Williams, Patricia

Third Advisor

O'Connell, Martin

Fourth Advisor

Allen, Charles


In June 2009 I conducted a study of the habitat associated with Broadleaf Barbara's Buttons (Marshallia trinervia) along Bird's Creek in Vernon Parish, LA. Twenty two plots were sampled for all vascular plants. Of these, 17 samples were from the area where M. trinervia was present and 5 samples were from the area where M. trinervia was absent. From each sampling plot a soil sample was collected and analyzed. There were significant differences in the species richness of all plant groups (p=0.0075), herbaceous plants (p=0.056), and woody vines (p=0.083) between the two locations. The soil texture was also significantly different in the percentage of sand (p=0.021), silt (p=0.029), and clay (p=0.089) between the study locations. The study found that the samples associated with M. trinervia were higher in species richness for all plant groups and the soils from these locations had a higher mean percentage of silt and clay particles.


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