Preliminary Microbial Community Analysis of Non-Native and Native Plants in the DePauw Nature Park Quarry Bottom

Authors

Madeleine Cruz, DePauw University
Dana Dudle, DePauw University

Files

Document Type

Poster

Publication Date

10-1-2025

Abstract

The DePauw Nature Park Quarry Bottom is a former limestone quarry that was mined for decades and then lay dormant. Through the years, it has developed from being uninhabited to being populated by a diversity of organisms at every scale of life. All organisms in the Quarry Bottom must withstand the changing conditions of the quarry, including the proliferation of invasive plants that are well-adapted to stress. In particular, two invasive wetland grasses, Phragmites and Typha have observed competitive interactions, increased spatial distributions, and possible influence on native species. We have studied these species at our scale of life, but seldom at a microbiological level. Although microorganisms are indicators of change, we have little understanding of their relationship to the Quarry Bottom or its plants. The microbial communities of different plant species might have distinct metabolic footprints from each other. To ascertain this, we conducted preliminary microbial community analysis using rhizosphere samples. A total of eighteen samples were collected from three species: the invasive Phragmites and Typha and a native sedge, Scirpus. From these, rhizosphere fractions were produced and inoculated onto corresponding EcoPlates. The EcoPlate contains 31 carbon sources that turn purple if metabolized. Absorbance (OD at 590 nm) was measured for a week and the average well color development calculated. Subsequent principal component analysis determined a strong correlation between PC 1 and species. PC 1 is associated with positive metabolic activity, i.e., carbon source utilization. We observed Scirpus to have a stronger relationship to PC 1 than Phragmites or Typha. One-way ANOVA confirmed this. Analysis of species metabolic activity by location revealed a species-location interaction. While this work is preliminary, it provides a basis for us to further explore the relationships between plants, rhizospheres, microbiomes, and the Quarry Bottom.

Department

Department of Biology, DePauw University, Greencastle, IN

Project Mentor

Dana Dudle

Funding and Acknowledgements

DePauw Faculty Development Committee

Recommended Citation

Cruz, Madeleine and Dudle, Dana, "Preliminary Microbial Community Analysis of Non-Native and Native Plants in the DePauw Nature Park Quarry Bottom" (2025). Annual Student Research Poster Session. 219.
https://scholarship.depauw.edu/srfposters/219