Ryerson’s Woods Park: A Relict Woodland?

Ryerson’s Woods is a wooded, 49 acre Iowa City park bisected by a deep ravine. It is well known locally for its showy spring flora, diversity of ferns and other unusual species. The purpose of our research is: 1) to document occurrence of plant species with collections and assess frequency of individual species in each habitat, and 2) to compare the present-day vegetation with that at the time of European settlement based on analyses of the 1837 land survey records. Over the 2009 growing season, extensive weekly field surveys, including pressed specimens and quantitative analyses, document high species diversity and a number of rare/infrequent species, particularly in the ravine. The historical records reveal the present-day wooded upland was open prairie or savanna with scattered burr, black and white oaks. The floodplain east of the park was densely treed with diverse species, and it is likely the ravine bottom and slopes harbored extensive patches of ferns, Wild Sarsparilla and Spikenard shaded by trees much as they are today. Our data suggest Ryerson’s Woods could be a good candidate for state preserve status.