Humans play an important role in restoring disturbed environments to their original structure (e.g., composition of vegetation) and function. Tallgrass prairie restoration, in particular is a timely issue because most of the historic extent of this ecosystem has been converted to agriculture. Despite much effort and interest, little is known about many factors that could influence restoration success. Widespread commercial production of prairie grass cultivars has resulted from efforts to develop native plants best for erosion control. Commercial production selects for vigorous traits to increase plant establishment. These traits, however, may increase the competitive ability of plants relative to plants of the same species from native prairie. Experimental plots will be established with cultivar or native prairie sources of the dominant prairie grasses along with a mix of prairie wildflowers in an agricultural field in southern Illinois. This experiment will monitor plant traits for four years and evaluate whether sources of grasses (i.e., cultivar and native prairie) influence the establishment of other species (i.e., wildflowers) and the recovery of other important processes that occur during restoration such as overall plant growth and improvements in soil health. Two additional sites in central Illinois and Kansas, containing similar experimental plots, will be monitored to generalize results to the tallgrass prairie region as a whole.
Although cultivars are widely used in prairie restorations, the long-term consequences (for community assembly and ecosystem recovery) of restoring habitats by introducing potentially more competitive plants are unknown. If cultivars are superior competitors, they may increase the difficulty in restoring the less abundant non-grass species that are critical to biodiversity. The nearly irreversible nature of plant composition once established from seed mixtures underscores the need for information on the ecological effects of species used in restorations. This is particularly relevant to tallgrass prairie, where restoring a variety of species is difficult to achieve.
