| |
| author |
Brady Thexton
| | title |
Surviving or thriving: carbon trade-offs between growth, defense, and floral reproduction in Rubus allegheniensis and R. phoenicolasius in Northcentral New Jersey, USA
| | abstract |
Little is known about the reproductive limits of semi-long-lived perennials,
especially how their other two primary life history functions (growth and defense) may
constrain reproductive investment. Understanding these constraints can help researchers
produce cultivating best practices for perennials like Rubus that produce nutritious fruits.
Here, we sought to elucidate the responses of carbon-demanding traits related to the
aforementioned life history functions in Rubus allegheniensis (blackberry) and R.
phoenicolasius (Japanese wineberry) to variable herbivory rates. We also discerned if
trade-offs are present between these traits in these species. We observed traits related to
physical defense (prickle intensity, leaf toughness, and stem basal diameter), growth
(cane length and average leaf size), and floral reproduction (flower number, number of
ripe fruits, fruit set, and fruit dry:wet mass ratio) as well as environmental characteristics
related to carbon availability (rates of herbivory and light availability). We then used
multiple regression models to characterize the relationships between these variables for
both species. We found several potential induced defenses in these species, most in
wineberry. Seven of the 29 trade-off models we ran returned significant results indicative
of potential trade-offs between life history functions. Our results should spur further
research into the defensive strategies utilized by these species because inducible defenses
may result in trade-offs reducing yields in cultivation and also be a mechanism that
increases the invasive potential of Rubus. In addition, our research suggests ways
wineberry may be invading the study region.
| | school |
The College of Liberal Arts, Drew University
| | degree |
B.S. (2020)
|
| advisor |
Alex Bajcz
|
| full text | BThexton.pdf |
| |
