Land Use and Urbanization as Drivers of Change in Soil Properties of Urban Remnant Prairies

Prairieland management is crucial in effective carbon sequestration. Due to the unique dynamics of prairie C3 and C4 plants, prairies are highly productive, regardless of remnant or restored status. Projects of prairie conservation and/or restoration are extremely important, but they are challenged by different conditions and affected by different management and disturbances. The goal of this study was to observe whether fire control as a management practice affects prairie heterogeneity and how it affects soil carbon and nitrogen, soil physico-chemical properties, and C3 and C4 plant balance in the James Woodworth Prairie Preserve (IL, USA). Within the Preserve, we selected five sites, three of which are unburned and two which are burned annually. Soil core samples were analyzed for Soil Organic Carbon (SOC), Total Nitrogen (TN), grams of C3 and C4 carbon, percent N, percent C, δ15N, δ13C, proportion of C4 and C3 carbon, bulk density, pH and field water capacity. A plant survey was also conducted to identify species at the five sites. We found that soil C and N were similar between most sites and soil depths, with a few exceptions. Most soil C comes from C3 plants, as the chosen sites are mostly C3 dominated. Soil N did not differ between sites except for the deepest part of one specific site (Road). Belowground temperature differed between burned and unburned sites. Our Road site had the most alkaline pH (7.6) while the other four sites did not differ in pH. We also identified 77 unique plant species between our five sites, most of which were C3 species. From our findings, we conclude that annual fires may not have as large an impact on JWP as originally thought, and soil and species composition may be larger contributing factors in shaping this prairie’s characteristics and diversity.