Abstract Detail



Ecology

Mesa , Joshua Miles [1], Dlugosch, Katrina [2].

Invaded Range Yellow Starthistle (Centaurea solstitialis) Exhibit Increased Tolerance to Herbivory.

The introduction of species into novel environments outside of its native range is regularly associated with large changes to its ecological interactions. The Evolution of Increased Competitive Ability (EICA) posits that introduced plants experience decreased regulation by their specialist herbivores and pathogens allowing for the evolution of reduced resistance and potential to outperform natives by increasing growth and fitness, given associated costs for defense compounds. However, how plants optimize investment in defenses relative to other functions remains poorly understood. In addition, the impoverished herbivore communities in a new region are primarily a result of the reduction of specialist enemies, while the level of generalist attack can vary considerably. An increase in damage by generalist herbivores may select for increased tolerance in the introduced range. Plant genotypes that can compensate for tissues lost with little or no decrement in fitness relative to those that are undamaged represent such an example and are termed ‘tolerant’. Importantly, plant tolerance has received relatively little attention in the context of plant invasions but could be an important defense mechanism for plant species that lack efficient chemical defenses. Here we investigate the compensatory ability in an economically important pest species using the highly invasive plant yellow starthistle (Centaurea solstitialis). This highly invasive forb is native to a wide region of Eurasia and was introduced from western Europe into South America in the 1600’s and subsequently into North America in the 1800’s. Along its severe invasion of western North America, yellow starthistle has evolved increases in size and reproductive potential, as well as reduced immune system activity consistent with EICA predictions. Here we show that invasive yellow starthistle are more tolerant to damage than native range populations.


1 - University of Arizona, Ecology and Evolutionary Biology, 1041 E. Lowell Street, Biosciences West Room 310, Tucson, Arizona, 85721, US
2 - University Of Arizona, ECOL AND EVOL BIOLOGY/ EMS, P.O. Box 210088, Tucson, AZ, 85721, United States

Keywords:
Invasive species
plant tolerance
herbivory
Trade-offs.

Presentation Type: Oral Paper
Number: ECO3001
Abstract ID:717
Candidate for Awards:None


Copyright © 2000-2020, Botanical Society of America. All rights reserved