George Washington Carver National Monument plant community report: 2004–2020
Authors: Leis Sherry , Short Mary 
Published: December 2021

The Heartland Inventory and Monitoring Network completed its sixth year of plant community monitoring at George Washington Carver National Monument in 2020. Plant community monitoring focused on the restored prairie community. We visited seven monitoring sites in each of the six years and collected data on plant species and ground cover. In this report we also included two environmental factors—precipitation and recent fire history—to better understand the vegetation community status and trends. Since 2000, precipitation has often been below the 30-year normal. Moreover, annual precipitation was below normal for all but one of the monitoring years. We found that the drought in 2012 stood out as possibly influencing plant guild cover. Although prairies are adapted to drought, further analyses might reveal more about the role of climate change in these vegetation communities. Fire management also plays an important role in shaping plant communities. Prescribed fire occurrence became more frequent and consistent through the period of plant monitoring. Additional treatments, including herbicide and mowing, also supported a healthy prairie. The prairie plant community continues to be moderately diverse despite recent increases in tree seedlings and small saplings. Species richness in 2012 was different than in two of the six years monitored. However, diversity indices (H′ and J′) were very similar across monitored years. Species guilds (also known as functional groups) exhibited differing patterns. Woody plants, long a concern at the monument, were statistically similar across years. In 2020, grass-like species increased, but grass species appeared to have declined below prior years. Grass cover in 2004 was statistically different (greater) than in 2008 and 2020. The reasons for this are not clear. Of particular interest to the park is the status of two sumac species (Rhus glabra and R. copallinum). These species were in decline as a result of focused management actions since 2012. However, the blackberry species (Rubus spp.) seemed to be replacing the sumac in some sites. In 2020, nonnative species richness and cover were below peak levels, demonstrating management actions have been successful in maintaining low levels. The vegetation monitoring protocol experienced some changes between 2004 and 2020. A key difference was a shift from sampling twice during the field season to sampling only once in a monitoring year. Although a decline in species richness was anticipated, that pattern was not apparent. However, the abundance of grasses may have been affected by the shift in seasonality of sampling. Additionally, we remedied inconsistencies in how tree regeneration was recorded (stem tallies in some cases and cover estimates in other cases). We converted all cover data to stem tallies and density was calculated to be consistent with the protocol. The monument has had success with coordinating fire management and invasive species management. A decrease in sumac across the prairie is evidence of this success. These actions will continue to be important for maintaining the prairie in good condition into the future.