Konza Prairie LTER

Network News Spring 1988, Vol. 3 No. 1
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Konza Prairie Research Natural Area, owned by the Nature Conservancy and managed by the Division of Biology at Kansas State University, is the largest research natural area in tallgrass prairie. Tallgrass prairie, a major ecosystem type in North America, once covered 6-7% of the conterminous United States. The Konza Prairie site is representative of the Flint Hills upland, which extends from Oklahoma to Nebraska, averaging about 70 km wide. This region is dissected upland with hard chert- and flint-bearing limestone layers, resulting in steep-sided hills on which are exposed Permian limestone and shale layers. The ridges are characteristically flat, with shallow, rocky soils, whereas the larger valleys have deep, permeable soils. Although undisturbed examples of tallgrass prairie are rare because of extensive conversion to agricultural crop production, most of the Flint Hills region could not be cultivated and large areas of tallgrass prairie, grazed by cattle, remain today.

Large grazing herbivores, lightning and anthropogenic fire, and periodic droughts were important influences on the plant and animal components of presettlement prairie. We have, therefore, focused our LTER research on the influence of fire, grazing, and climatic variation on populations and processes in tallgrass prairie. Effects of fire on tallgrass prairie has been studied since the establishment of Konza Prairie in 1971, with the initiation of the LTER effort work of the effects of fire was intensified and the collection of detailed climatic data began. In October 1987, 33 bison were introduced to approximately 470 hectares of the site. Preliminary studies of bison have been initiated in preparation for the introduction of bison to an add itional 520 hectares of prairie in 2-3 years. With a larger herd of bison, approximately 150 individuals, in a less restricted area including watersheds with monitored streams, we will be able to more fully examine interactions between native grazers and prairie fires.

To investigate the effects of fire on tallgrass prairie, watershed scale burning treatments with fire frequencies of 1, 2, 4, 10, and 20 years were established beginning in the 1970’s. Although the effects of annual burning versus no burning on ungrazed tallgrass prairie has been studied at Kansas State University for 60 years, studies on Konza Prairie will provide the first test of the effects of other frequencies of fire. Burning every few years, for example, produces a pattern of plant production related to fire frequency. Also, plant species composition is influenced by fire and time since fire including greater similarity of the vegetation in upland and lowland sites burned annually than similar sites several to many years post-fire. Fire and recovery of vegetation following a fire impact consumer populations, e.g., grasshoppers and small mammals, with assemblage recovery dependent on species-specific patterns of fire-positive and fire-negative responses. In 1988, large portions of Konza, not burned since the mid to late 1960’s, will be burned providing an excellent opportunity to test a number of concepts and predictions about the effects of fire that LTER researchers have developed over the last few years.

Since the start of the growing season of 1986, we have expanded LTER research to include experimental analyses of the belowground components to better understand pattern and processes in the total prairie system. A major part of these efforts has involved the establishment of an intensive factorially designed study involving burning, mowing (to simulate grazing), and fertilization (N, P and N + P) of experimental plots. Research on these plots includes analyses of soil properties, root biomass, types and associations of mycorrhizal fungi, and abundance and types of soil nematodes coupled with measurement of aboveground biomass and seed production. Results are beginning to provide insight into the effects of soil microbial activities on the processing of organic matter and the long-term effects of annual burning and nitrogen and phosphorus additions on the chemistry of tallgrass prairie soils. Additionally, data on root growth and production are being collected using root windows to measure growth and senescence of individual roots and soil cores to estimate standing crops of roots. The vertical and horizontal movement of soil water and any possible effects of annual burning on these movements is also included in the belowground component of KONZA LTER.

As part of its National Hydrological Benchmark Network, the U.S. Geological Survey have maintained hydrological records for Kings Creek, the major stream on Konza Prairie, since spring 1979. In addition, four triangular-throated flumes draining catchments of the upper portions of Kings Creek are being used to collect long-term discharge measurements. Work is now progressing on a hydrological model for flows in different watersheds. In addition to flow data, measurements of water quality are routinely taken from the four flumed watersheds. Data on water flow and quality are regionally important since this is the only stream monitored by the U.S. Geological Survey that drains into a major river that does not have its headwater in agricultural areas and, therefore, the Kings Creek serves as benchmark stream for the rest of the Great Plains agricultural area.

Detailed satellite imagery of Konza Prairie for the 1987 growing season was collected as a result of NASA’s FIFE program, and will eventually be available to investigators not originally involved in the FIFE project. To facilitate the use of these and other types of digital data, an ERDAS Image Processor is now available as part of the LTER data management effort. Our initial use of this system coupled with a GIS is focused on the prediction of primary production of the tallgrass prairie and spatial analysis of the distribution of woody plant species on Konza Prairie.

For information on the Konza LTER program contact Dr. Donald W. Kaufman, Division of Biology, Kansas State University, Manhattan, KS 66506. For information on research opportunities on Konza Prairie Research Natural Area contact Dr. Ted M. Barkley, Division of Biology, Kansas State University, Manhattan, KS 66506.