<p>Amur honeysuckle (<i>Lonicera
maackii</i>) is a shrub endemic to East Asia which has become invasive and
nearly ubiquitous to the forest ecosystems of eastern North America. Through
its extended growing season, competitive ability, and potential allelopathy,
Amur honeysuckle alters native herbaceous-layer plant communities and inhibits
the regeneration of native tree species. As such, it is representative of a
range of invasive shrub species imported from East Asia. My thesis contributes
to questions fundamental to the understanding this and other invasive shrubs:
1) How do species become invasive? 2) How can the invasions of the species be
effectively controlled? 3) How does the ecosystem respond to treatment of the
invasive species?</p>
<p>First, I examined the role of
self-compatibility within Amur honeysuckle. I compared the berry production,
seed production, and germination rates between closed-pollinated and
open-pollinated flowering branches of Amur honeysuckle individuals across
multiple types of invasions (heavy, light, and sprouting). I found that Amur
honeysuckle not only possesses the ability to self-pollinate, but that it can
produce viable self-pollinated seed sets. This ability may help explain how
Amur honeysuckle able to invade isolated forest patches far removed from the
main invasion.</p>
<p>Second, I evaluated the
effectiveness of a novel herbicide adjuvant in reducing the amount of herbicide
needed in the ‘cut-stump’ method of controlling Amur honeysuckle. Combining
various concentrations of the most common herbicide in the world, glyphosate,
with concentrations of cellulases derived from fungi, 2XL, I examined whether
the cellulases improved the effectiveness of glyphosate, potentially by
increasing glyphosate movement into the vascular tissue of Amur honeysuckle
through the degradation of cell walls. While 2XL was not an effective adjuvant,
glyphosate concentrations of less than half the recommended dosages were
equally effective as higher concentrations in preventing sprouting of treated
stumps. The ineffectiveness of 2XL may imply a need for protein-mitigated
diffusion of glyphosate across cell walls and into the vascular tissue of the
plant, which would be inhibited by the breakdown of cell walls.</p>
Finally, I tested how
deeper intensities of mulching-head treatments affected the sprouting response
of Amur honeysuckle and the response of the herbaceous-layer plant community
after treatment. I found a negative relationship between the volume of
sprouting Amur honeysuckle and increasing depth of mulching-head treatment.
Additionally, increasing mulching-head intensities were correlated with
increased herbaceous layer diversity and conservation value as represented by
Floristic Quality Index. Mulching-head treatments are a promising tool in
controlling heavy invasions of non-native shrubs.
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/15078279 |
| Date | 29 July 2021 |
| Creators | Benjamin Joseph Rivera (11205324) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/thesis/The_Establishment_Control_and_Post-Control_Response_of_Amur_Honeysuckle_Lonicera_maackii_/15078279 |
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