Monitoring Tallgrass Prairie Restoration Performance Using Floristic Quality Assessment

Floristic Quality Assessment (FQA) is a tool that allows botanists to quickly and effectively determine the natural quality of sites. Several uses for FQA have been proposed, but it has primarily been used to identify and rank areas of remnant natural quality. It has experienced limited use in long-term monitoring projects. FQA was validated for this use by means of data collected over 13 years from the Upland Prairie Restoration (Upland, Grant County, Indiana). In 1993, the year of planting, permanent monitoring transects were established, including two controls, two enriched with nitrogen from 1993-1997, and three in an area prone to intermittent seasonal flooding. FQA was applied to species cover data collected on an irregular basis from these transects from 1993 through 2005. Analysis of the control transects revealed that mean C (MC) and floristic quality index (FQI) values rose with increasing site age. This indicated that the site’s floristic quality was improving over time. Species dominance shifted from native and adventive weeds to native prairie grasses and forbs. Quadrat level metrics were more valuable for elucidating trends because transect level metrics were easily affected by slight differences in species composition year to year. Analysis of the nitrogen-enriched transects showed very low floristic quality as measured by quadrat MC and FQI. These improved markedly from 2000 to 2005 following cessation of fertilizer addition, demonstrating that the vegetation was recovering from this negative treatment. Transects most prone to intermittent seasonal flooding received lower MC and FQI scores because flooding inhibited the establishment of some prairie species. The vegetation of the transect positioned lowest in the landscape achieved the lowest mean wetness scores, indicating that the vegetation was more representative of a wet meadow than a prairie. This research determined that FQA is a cost-effective, useful tool for examining trends and responses to treatments and disturbances in prairie restorations