An Assessment of Disturbed Populations at Faville Prairie: Silphium terebinthinaceum and Silphium laciniatum Population Recovery

Abstract

Faville Prairie is a remnant prairie adjacent to the Crawfish River in Jefferson County, Wisconsin. This prairie has been surveyed several times, notably in 1978 and 2010. These two surveys were done before and then after a significant flooding event that occurred at Faville Prairie in 2008. The comparison of the previous surveys showed a severe decline in the populations of several plant species, including the target species Silphium terebinthinaceum (prairie dock) and Silphium laciniatum (compass plant). The present study resurveyed Faville Prairie in 2019 to evaluate the rate at which Silphium terebinthinaceum and Silphium laciniatum have recovered from the population crash. Target species were also located outside of the survey plots to determine seed output and reproduction success. Abundance in the 2019 surveys was not significantly different than abundance in the 2010 survey for both Silphium terebinthinaceum and Silphium laciniatum. From these results, we conclude that the populations have not yet recovered from their drastic declines in abundance, and the prairie ecosystem may have experienced a shift in its stable state due to environmental drivers. Given predicted increases in extreme weather events due to climate change, plant population declines may be occurring more often, as habitats change. This will have implications on biodiversity and ecosystem functions of grassland ecosystems.