Cool-Season Turfgrass Survival in Restored Wisconsin Prairies.

In April of 2006, the Invasive Species Advisory Committee (ISAC) issued a White Paper to characterize and define invasive plant species. Kentucky bluegrass (Poa pratensis L.) specifically mentioned as both an invasive and non-invasive species. The ISAC used Kentucky bluegrass to demonstrate the importance of the organism’s biogeographical context, describing how it can be an invasive species in Rocky Mountain National Park and non-invasive at a nearby location outside the park boundaries. Non-native grasses have been linked to the displacement of native species and reduction of native biodiversity. Our study was designed to determine the level of invasiveness cool-season turfgrasses pose to restored prairies. During the fall of 2006, live turfgrass and turfgrass seed survivability studies were established at two restored prairie locations in Wisconsin. The soil series at the northern site is a Fenwood silt loam and a Durand silt at the southern location. Eleven commonly used turfgrass species/cultivars were established in five replications arranged in a randomized complete block design. The lateral and horizontal growths of the specimens were recorded during the growing season. To date, predation from herbivores has been a significant obstacle to the successful establishment and spread of the turfgrass plants. The surviving plants exhibit sink population characteristics as leaf tissue and reproductive structures are frequently removed prior to progeny production. Six turfgrass species/varieties seeds and three native grass seed species were placed under a light barrier and buried 5 cm under the soil surface in a randomized complete block design. Five replications containing each type of seed will be exhumed at seven separate time intervals. Following extraction germination is tested and a tetrazolium test performed on ungerminated seeds to determine if dormancy exists. Initial data on seed survivability suggests that viability decreases dramatically within the first 6 months in soil seed bank conditions.