About This Project

Once common, prairies are now among the most threatened of ecosystems. Restoration of prairies without intense management is challenging. Introducing native parasitic plants can reduce aggressive species but broader effects of hemiparasites (green parasitic plants) on invasions and productivity are unknown. Our goal is to evaluate species composition and environmental factors in prairies with native hemiparasites to understand these effects and provide critical insights to land managers.

Ask the Scientists

What is the context of this research?

Eastern tallgrass prairie once seemed limitless, but farming and development have devastated this ecosystem. In Illinois, high-quality prairie occupies <1% of the former area. In every prairie state, managers are working to revive this ecosystem.

Restoration of fully functioning communities requires manpower and resources. Because a species-rich community is a hallmark of successful restoration, strategies for limiting aggressive species that suppress desirable species are needed. Hemiparasites (green parasitic plants) extract water and minerals from neighbors' vascular systems, reducing host growth. Dominant species are the most strongly affected. Adding native hemiparasites to suppress dominant species and to increase species diversity may thus benefit restoration.

What is the significance of this project?

Prairies are complex. Plants interact above and below ground with other plants, microbes, and animals. If hemiparasites improve balance on a prairie, as defined by site managers, time and effort costs may be reduced and success of restoration increased. But, the idea of using hemiparasites as "tools" comes from anecdotes or studies of non-prairie systems. Greater diversity may result if hemiparasites facilitate invasions by unwanted non-native species.

Humans have exacerbated imbalance among species when we have introduced a new player to a community. Land managers need to know if native hemiparasites can be used to limit other species and to enhance prairie diversity. Thus, we need to understand the full range of direct and indirect effects of hemiparasites in prairies.

What are the goals of the project?

To understand the role hemiparasites play in prairie communities and their potential to aid in prairie management we will conduct vegetation surveys of prairies with different characteristics, analyze environmental data (light, soil nutrients), and model interactions. Our goal is to answer these questions: Are these green parasites associated with greater numbers and abundances of native species? Where hemiparasites are abundant, are exotic species more common? Do hemiparasites have stronger effects in prairies where host plants are limited by nutrients? Hemiparasites debilitate hosts, and so we also wonder how much productivity declines as hemiparasite abundance increases. This effect of hemiparasites is not trivial if large-herbivore grazing is an essential part of management plans.