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Premise of the Study: Mammalian herbivores, particularly white-tailed deer, can have a major impact on plant abundance and distribution. However, plants can tolerate herbivory by increasing seed production or seed quality. We used the monocarpic perennial Prenanthes roanensis to examine tolerance to mammalian herbivory through seed quality and modeled the effects of tolerance on population growth rate., Methods: We examined seed quality (proportion of viable seeds, seed mass, germination, and seedling size) on damaged and undamaged plants to determine the extent to which plants tolerate herbivory. We then varied seed quality parameters over a range of values in population models to compare population growth rates under "no-tolerance" conditions (herbivory, but no tolerance) to those under "tolerance" conditions., Key Results: In most populations, plants damaged by herbivores had a greater proportion of viable seeds per plant or a greater probability of seed germination. Incorporating observed tolerance into population models did not significantly increase population growth rate. However, at low germination rates, increased germination of seeds from damaged plants has the potential to significantly increase population growth rate., Conclusions: Damaged plants can compensate for loss of reproductive heads by increasing seed viability and germination rates in the remaining seeds. This study is one of the first to demonstrate that tolerance through seed quality has the potential to affect population growth rate. Our results suggest that incorporating tolerance into population models may help elucidate mechanisms by which plant populations persist despite herbivory., (© 2015 Botanical Society of America.)

Premise of the Study: The ecological consequences of plant competition have frequently been tested, but the evolutionary outcomes of these interactions have gone largely unexplored. The study of species invasions can make an important contribution to this field of research by allowing us to watch ecological and evolutionary processes unfold as a novel species is integrated into a plant community. We explored the ecological and evolutionary impact of an invasive jewelweed, Impatiens glandulifera, on a closely related native congener, I. capensis and asked: (1) Does the presence of the invasive jewelweed alter the fitness of native jewelweed populations? (2) Does the invasive jewelweed affect the vegetative growth of the native congener? and (3) Does the invasive jewelweed alter phenotypic selection on the vegetative traits of the native congener?, Methods: We used a greenhouse competition experiment, an invasive species removal field experiment, and a survey of natural populations., Key Results: We show that when the invasive jewelweed is present, phenotypic selection favors native jewelweed individuals investing less in rapid upward growth and more in branching and fruiting potential through the production of nodes., Conclusions: This research demonstrates that invasive plants have the potential to greatly alter natural selection on native competitors. Studies investigating altered selection in invaded communities can reveal the potential evolutionary impact of invasive competitors, while deepening our understanding of the more general role of competition in driving plant evolution and permitting species coexistence., (© 2015 Botanical Society of America, Inc.)

Unlabelled: •, Premise of Study: Recent studies suggest that invasive plants compete reproductively with native plants by reducing the quantity or quality of pollinator visits. Although these studies have revealed ecological consequences of pollinator-mediated competition between invasive and native plants, the evolutionary outcomes of these interactions remain largely unexplored.•, Methods: We studied the ecological and evolutionary impact of pollinator-mediated competition with an invasive jewelweed, Impatiens glandulifera, on a co-occurring native congener, I. capensis. Using a pollinator choice experiment, a hand pollination experiment, and a selection analysis, we addressed the following questions: (1) Do native pollinators show preference for the invasive or native jewelweed, and do they move between the two species? (2) Does invasive jewelweed pollen inhibit seed production in the native plant? (3) Does the invasive jewelweed alter phenotypic selection on the native plant's floral traits?•, Key Results: The pollinator choice experiment showed that pollinators strongly preferred the invasive jewelweed. The hand pollination experiment demonstrated that invasive pollen inhibited seed production in the native plant. The selection analysis showed that the presence of the invasive jewelweed altered phenotypic selection on corolla height in the native plant.•, Conclusions: Invasive plants have the potential to alter phenotypic selection on floral traits in native plant populations. If native plants can evolve in response to this altered selection pressure, the evolution of floral traits may play an important role in permitting long-term coexistence of native and invasive plants., (© 2015 Botanical Society of America, Inc.)