Effects of invasive plant species on reproduction of the rare endemic plant Dakota buckwheat (Eriogonum visheri) at Badlands National Park

Endemism in plants is extremely uncommon in the Great Plains.  Dakota buckwheat is a rare, endemic plant found in only a few locations at Badlands National Park and sites with similar soils outside the park.  In an earlier study, Northern Prairie Wildlife Research Center inferred that of two common, co-flowering invasive plants, Russian thistle was more likely than yellow sweetclover to interfere with Dakota buckwheat pollination.  This inference was based on an analysis that grouped pollinating insects and flowering plants into groups, called modules, in which pollinators and plants were statistically more likely to interact with each other than with those outside their module.  In this study, we explicitly test the impact of these two invasive plants on visitation, pollen limitation, and seed set of Dakota buckwheat. By doing the meticulous work this study requires, we will be able to better interpret other studies that only investigate visitation without assessing seed set, and provide managers with information needed to manage invasive plants near this rare endemic plant.