Soil and Plant Property Differences Across a Chronosequence of Humid-Temperate Tallgrass Prairie Restorations

The potential effects of grassland restoration in the warm-temperate humid zone of the midsouthern United States have received much less attention than that in the upper midwest or Great Plains. Restoration response will likely differ from that observed in other regions under different climate regimes. The objective of this study was to evaluate the effects of prairie restoration on near-surface soil properties and vegetation characteristics across a chronosequence of tallgrass prairie restorations (i.e., 3, 4, 5, and 26 years old) and a local native tallgrass prairie in the Ozark Highlands. Soil bulk density, pH, electrical conductivity, extractable P, K, Ca, Mg, Na, S, Fe, Mn, Zn, and Cu, organic matter, and total N and C in the top 10 cm, aggregate stability, soil surface carbon dioxide flux, and aboveground and belowground plant dry matter and N and C contents were determined along a 60-m transect established in the soil mapping unit most similar among each ecosystem between Fall 2005 and Fall 2006. All soil properties evaluated differed (P < 0.05) among the prairie ecosystems. Most extractable soil nutrients decreased, whereas soil organic matter and total C increased with restoration age and tended toward that observed in the native prairie. Soil surface carbon dioxide flux did not differ systematically (P = 0.20) among prairie ecosystems, but maximum fluxes were observed at approximately 50% water-filled pore space. Neither aboveground biomass nor necromass dry matter differed, although root biomass and C and N contents late in the 2006 growing season differed among prairie ecosystems. The known historic presence of tallgrass prairie throughout the Ozark Highlands suggests that current and future tallgrass prairie restorations can be ecologically successful in the region, but the combination of topographic, edaphic, and climatic conditions of the region may also provide unforeseen challenges to restoration managers.