North American Prairie Conference


Date of this Version



Published in Dave Egan & John A. Harrington, editors, Proceedings of the 19th North American Prairie Conference: The Conservation Legacy Lives On..., University of Wisconsin-Madison, August 8-12, 2004 (Proceedings of the North American Prairie Conference, 19), Madison, WI: University of Wisconsin-Madison, 2004.


Many practitioners prefer to plant seed from multiple remnant sources within the same region of the planting site. It is believed that this seed has improved fitness (survivorship, growth, and viability) over seed from outside the region. We tested this assumption by establishing two common gardens in northern and southern Iowa. Four varieties of switchgrass (Panicum virgatum) from prairie remnants in northern and southern Iowa and two cultivated varieties from Nebraska and South Dakota}, and stiff tickseed (Coreopsis palmata) from prairie remnants in northern and southern Iowa, were established in a greenhouse and transplanted into each common garden in May 2002. We hypothesized that plants grown near their origin would have improved fitness over those from distant origin. Stiff tickseed showed a trend of more shoots in regional populations vs. distant populations, though no significant differences in any of the measures of fitness between Northern and Southern Iowa populations were found. Iowa remnant populations of switchgrass had significantly (P < 0.05) more shoots per plant compared to at least one cultivar in both common garden sites in 2002 and 2003. Nebraska 28 cultivar of switchgrass experienced greater mortality than Iowa remnant populations. However, seed viability was not significantly (P < 0.05) different for the cultivated varieties of switchgrass and Northern populations; but was significantly lower for Southern Iowa populations in 2002. A decrease in fitness was measured when switchgrass seed from distant sources was planted in Iowa. The results suggest that switchgrass from various Iowa prairie remnants can be planted throughout the state without a loss of fitness.