Abstract Detail

Ecology

Moore, Cheyenne [1], Heberling, Mason [2], Kuebbing, Sara [3].

Invasive hybrid vigor? Niche and trait variance between three knotweed taxa.

Knotweed (Polygonaceae) are problematic invaders around the globe, with their prolific spread impacting many ecosystems. Here in western Pennsylvania, there are three taxa that invade locally: Japanese knotweed (Reynoutria japonica Houtt.), giant knotweed (Reynoutria sachalinensis (F. Schmidt) Nakai), and their hybrid, Bohemian knotweed (Reynoutria × bohemica Chrtek & Chrtková). These taxa, though common and with sympatric nonnative ranges, do not appear to occur within the same local habitats based on herbarium records and community science observations. This leads to our key question: What are the ecological mechanisms driving this observational pattern? One hypothesis is that the three taxa are niche partitioning, where they are found in differing habitats. Alternatively, if multiple taxa are present at a given site they will compete for habitat. If taxa are in direct competition, we hypothesize that R. x bohemica, the hybrid taxon, will have the highest fitness and be able to out-compete parent taxa based on the concept of hybrid vigor, which has been empirically supported elsewhere in the taxon’s range. To investigate niche partitioning and fitness of the taxa, we collected habitat and functional trait data for all three taxa at a site in western Pennsylvania where the three taxa co-occur. Preliminary results indicate there is trait variance between taxa. Overall, this work will provide a better understanding of the role of these invaders in the ecosystems they invade and will inform future research regarding mechanisms of impacts. Our work will also have applied management applications. In particular, if the hybrid is shown to have higher fitness functional traits, indicating hybrid vigor, managers might want to prioritize management of the hybrid over the parent taxa.

1 - University of Pittsburgh, 4249 Fifth Ave, Pittsburgh, PA, 15260, United States
2 - Carnegie Museum Of Natural, Section Of Botany, 4400 Forbes Ave, Pittsburgh, PA, 15213, United States
3 - University Of Pittsburgh, Biological Sciences, 4249 Fifth Avenue, Pittsburgh, PA, 15206, United States

Keywords:
knotweed
hybrid vigor
invasion
functional traits
niche partitioning
plant community ecology
Polygonaceae.

Presentation Type: Poster
Session: P1, Ecology Posters
Location: Virtual/Virtual
Date: Monday, July 19th, 2021
Time: 5:00 PM(EDT)
Number: P1EC003
Abstract ID:176
Candidate for Awards:None