The focal site for the Konza Prairie LTER program is the Konza Prairie Biological Station (KPBS). KPBS is a 3,487 hectare native tallgrass prairie preserve owned by The Nature Conservancy and Kansas State University and operated as a field research station by the K-State Division of Biology. KPBS is located in the Flint Hills region of northeastern Kansas (39°05'N, 96°35'W). The Flint Hills are steep-sloped and overlain by shallow limestone soils unsuitable for cultivation. This region encompasses over 50,000 km2 throughout much of eastern Kansas from near the Kansas-Nebraska border south into northeastern Oklahoma and contains the largest remaining area of unplowed tallgrass prairie in North America. KPBS has a continental climate characterized by warm, wet summers and dry, cold winters. Mean annual precipitation (835 mm) is sufficient to support woodland or savanna vegetation; consequently, drought, fire and grazing are important in maintaining this grassland. The site is topographically complex (320 to 444 m asl), and soil type and depth varying with topographic position. In general, lowland soils are silty clay loams formed from thick colluvial and alluvial deposits and may extend to 2 m. Hillside and upland soils are similar, but much shallower. These soils overlay as many as 10 distinct layers of alternating limestone and shale, contributing to the complex subsurface hydrology of the region.
The vegetation at KPBS is primarily (>90%) native tallgrass prairie, dominated by perennial C4 grasses, such as Andropogon gerardii, Sorghastrun nutans, Panicum virgatum and A. scoparius. Numerous sub-dominant grasses, forbs and woody species contribute to its high floristic diversity. The KPBS biota includes >600 plant, 40 mammal, >200 bird, 34 reptile and amphibian, 20 fish, and >700 identified invertebrate species. Kings Creek, a USGS Benchmark Stream, originates on and traverses 10 km across KPBS. Gallery forests dominated by Quercus spp. and Celtis occidentalis occur along major stream courses. Several agricultural fields and restored prairies occur near headquarters. Overall, the site has most features representative of the pre-settlement tallgrass prairie, with fire and large native herbivores incorporated as a shifting mosaic. Thus, Konza Prairie serves as a benchmark for detecting and exploring the causes and consequences of environmental change taking place throughout the grasslands of the eastern Central Plains, with results relevant to mesic grasslands worldwide.
The Konza LTER program is built upon a long-term database on ecological patterns and processes derived from a fully replicated watershed-level experimental design, in place at KPBS since 1977. This design includes replicate watersheds subject to different fire and grazing treatments. In addition to these watershed-level manipulations, the Konza LTER program includes a number of long-term plot-level experiments. The effects of climate are addressed by long-term studies encompassing the natural climatic variability, and possible directional changes, characteristic of this region, as well as manipulations of water availability and stream hydrology in field experiments. Within core LTER watersheds, permanent sampling transects are replicated at various topographic positions (n=4/topo. position/watershed), where ANPP, plant species composition, plant and consumer populations, soil properties, and key above- and belowground processes are measured. Stream weirs and permanent sampling locations facilitate long-term data collection in grassland streams. The collection of diverse data from common sampling locations facilitates integration among our research groups.
Facilities available at KPBS includes the 4,650 ft2 Hulbert Center housing a library/conference room, classroom, offices, teaching laboratory, reference herbarium and animal collections, and dormitory-style housing for 15 visitors. Two new 2-bedroom cottages can house an additional 10 visiting researchers. The 2,400 ft2 Ecology Laboratory includes 2 analytical labs, a soil and root processing lab, a computer room, and researchers’ shop. Other station buildings include a fire station and shop/maintenance building, storage for research equipment, materials, and archived samples, and a residence for on-site staff. All KPBS headquarters buildings have T1 Internet connectivity. Other field equipment and instrumentation at the site includes an eddy flux tower for quantifying ecosystem-level C flux, four weirs and associated stream gauging equipment, 46 wells for monitoring groundwater levels and chemistry, numerous TDR probes and neutron access tubes for soil water measurements. On-site monitoring instrumentation includes a CIMEL Sun Photometer, a USGS stream monitoring station, Climate Reference Network (CRN) weather station, and wet (NADP) and dry-deposition (CASTNet) monitoring facilities.