The Konza Prairie, Northeast Kansas, USA: The hydrologic evolution of a merokast landscape

The Konza Prairie Biological Station (Konza or KPBS - 3,487 ha) is a LTER and NEON site, located in the northeastern part of the Flint Hills physiographic province of Kansas. Konza contains one of the few remaining remnants of tallgrass prairie in the United States that has not been irrevocably altered by agricultural intensification and other land management. Located on the western edge of the former tallgrass prairie biome that once covered close to 688,000 km2, it may be considered as a reference ecosystem against which altered prairie landscapes may be compared. However, Konza itself is a merokarst geology (i.e. karstic carbonate layers interbedded with mudstone) mantled by loess which is gradually evolving under long time scale climatic variability, and short timescale changes in land-cover arising from experimental design. At Konza, scheduled range burning and controlled grazing by native and non-native ungulates have resulted in trends of woody vegetation encroachment, particularly in infrequently burned watersheds, over the past c. 30 years. In concert with these land-use changes there has been steady increase in groundwater carbon dioxide concentrations and changes to the chemical weathering rates of the bedrock. A better understanding of the above-ground and below-ground changes at the KPBS will provide insight into historical conditions, permit projections regarding the future of this ecosystem, and facilitate commentary on the status of other prairie and former prairie areas. Development of a conceptual framework for a changing tallgrass prairie in a mesic climate requires integration of several interdependent sciences: a) meteorology and climate science, b) soil science, c) ecohydrology, and d) hydrogeology, with elucidation of the specific hydrologic drivers within each of these fields. This research will provide a synthesis of over three decades of research at KPBS and presents a conceptual framework for prairie landscape evolution.