HOW RESILIENT ARE VEGETATION COMMUNITIES TO CLIMATE CHANGE AT THE CIHA FEN (JOHNSON COUNTY, IA, USA)

The distribution of water availability and soil properties at a site creates a suite of hydrological niches occupied by different vegetation communities. Water availability is a primary determinant of vegetation patterning, and is itself a function of soil properties, landscape position, climate, and other factors. Here, we take the Ciha Fen (Johnson County, IA, USA) as a case study in the resilience of current vegetation communities to changes in hydrologic drives (e.g., precipitation, ET). Based on field monitoring, three vegetation communities (wetland, transitional, upland) occupying at least three unique soil types at the site were studied. These field data were used to calibrate a 1-D numerical model to predict water availability as a function of climate, using changes in precipitation and evapotranspiration to drive the model. This model was used to predict the magnitude of hydrological variability required for vegetation patterning to change on the landscape (i.e., for the hydrological conditions in one soil type to become more suitable for a different vegetation community). Results of this study will support ongoing management of the Ciha Fen preserve.