Abstract Title

An allelopathic compound is a driving factor in the encroachment of eastern red cedar

Abstract

The problem: Eastern red cedar Juniperus virginiana is a native-invasive tree that is rapidly spreading across the Midwestern United States and has encroached as far as South Dakota and Nebraska. It is a serious problem in rangelands because cattle and sheep do not eat woody plants. We investigated the role of allelopathy, the chemical inhibition of one plant by another through the release of chemical suppressants or growth inhibitors into the soil. We wished to establish whether these plants were able to suppress the germination and growth of a dominant grass, big bluestem Andropogon gerardii.

Methods: We applied root exudate of J. virginiana to seeds of A. gerardii in petri dishes and applied distilled water as a control. We also compared germination and growth rates of A. gerardii in the presence and absence of oaks as potential competitors with the eastern red cedar trees.

Results: There was significantly lower germination of A. gerardii grown in the root exudate than controls of this species (grown in distilled water). This result demonstrated that J. virginiana contained significant allelopathic chemicals. However, we found no significant difference in A. gerardii germination between oak vs. no oak for the root exudate. In a subsequent experiment, we found no significant difference in relative growth rates between those growing with and without oaks and controls. Thus, the main allelopathic effect of eastern red cedar is in suppressing germination of this grass species. Allelopathy may be an important reason for the successful dispersal of this native-invasive species.

Modified Abstract

Juniperus virginiana is a native-invasive tree that is rapidly spreading across the Midwestern United States. It is a serious problem in rangelands because cattle and sheep do not eat woody plants. We investigated the role of allelopathy, the chemical inhibition of one plant by another, with an experimental design that determined if J. virginiana could suppress the germination and growth of a dominant grass, Andropogon gerardii. A root exudate from J. virginiana trees grown with the presence and absence of competing oaks were applied to A. gerardii seeds and distilled water used as a control. We found that J. virginiana contained significant allelopathic chemicals that suppressed germination of this grass species. Allelopathy may be an important reason for the successful dispersal of this native-invasive species.

Research Category

Biology/Ecology

Primary Author's Major

Botany

Mentor #1 Information

Dr. David Ward

Presentation Format

Poster

Start Date

5-4-2018 1:00 PM

Research Area

Biology | Botany | Ecology and Evolutionary Biology | Plant Biology

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Apr 5th, 1:00 PM

An allelopathic compound is a driving factor in the encroachment of eastern red cedar

The problem: Eastern red cedar Juniperus virginiana is a native-invasive tree that is rapidly spreading across the Midwestern United States and has encroached as far as South Dakota and Nebraska. It is a serious problem in rangelands because cattle and sheep do not eat woody plants. We investigated the role of allelopathy, the chemical inhibition of one plant by another through the release of chemical suppressants or growth inhibitors into the soil. We wished to establish whether these plants were able to suppress the germination and growth of a dominant grass, big bluestem Andropogon gerardii.

Methods: We applied root exudate of J. virginiana to seeds of A. gerardii in petri dishes and applied distilled water as a control. We also compared germination and growth rates of A. gerardii in the presence and absence of oaks as potential competitors with the eastern red cedar trees.

Results: There was significantly lower germination of A. gerardii grown in the root exudate than controls of this species (grown in distilled water). This result demonstrated that J. virginiana contained significant allelopathic chemicals. However, we found no significant difference in A. gerardii germination between oak vs. no oak for the root exudate. In a subsequent experiment, we found no significant difference in relative growth rates between those growing with and without oaks and controls. Thus, the main allelopathic effect of eastern red cedar is in suppressing germination of this grass species. Allelopathy may be an important reason for the successful dispersal of this native-invasive species.