Vegetation of the Willa Cather Memorial Prairie.

The purpose of this study was to analyze the interrelationships of the Willa Cather Memorial Prairie in terms of the characterizing species and types of vegetation. At each of 100 sample stand locations data were obtained on the 244-ha prairie in Webster County, Nebraska, to estimate percent basal cover and percent species composition. Estimates were analyzed quantitatively with the aid of vegetation ordination techniques, from which 15 vegetation types were discerned. Of the 15 types, two accounted for over 40% of the stands: a Kentucky bluegrass (Poa pratensis)buffalograss (Buchloe dactyZoides)-blue grama (Bouteloua grac&)-type and a Kentucky bluegrass-sideoats grama (Bouteloua curtipenduh)-big bluestem (Andropogon gerardi) type. Two secondary types accounted for another 16% of the stands, whiie the remaining 44% of the stands were fairly evenly dispersed within nine other types. Uplands were predominately Kentucky bluegrass, buffalograss, blue grama, and Japanese brome. Sideoats grama, little bluestem (Andropogon scoparius), and Kentucky bluegrass dominated hillside stands. Most abundant in lowlands were Kentucky bluegrass, sideoats grama, Japanese brome, and big bluestem. Due to the abundance of Kentucky bluegrass, late spring burning was prescribed to improve the condition and productivity of the prairie. The continuum concept of vegetation has the premise that Whittaker (1956, 1967), and Goodall (1963) in which some form of ordination was utilized. Ordination of vegetation was apparently first defined by Goodall (1954) as an arrangement of species or stands in a unior multidimensional order by individual values. Ordination may also be defined as “the arrangement of ecological entities in a spatial model with a relatively small number of axes, in order to reflect the relationships between these entities in terms of the variables characterizing them” (Maarel 1969). In practice the divergence between classification and ordination is not great (Greig-Smith 1964). Various ordination techniques may be utilized to arrange species or stands either directly or indirectly along an axis. The techniques used herein were of the indirect category, and information from the ordination procedures was used to order the stands, then classify them into types as connoted by the definition of Maarel (1969). The area of study consisted of a 244-ha tract of Mixed Prairie located in the loessial region of south-central Nebraska (T. lN, R 11 W, Sec. 35; 9.6 km south of Red Cloud, Webster County). It is bordered on the south by the Kansas state line and on the east by U.S. Highway 28 1. The Willa Cather Memorial Prairie consists of uplands that vary from level and gently sloping to “communities occurring-along continuous environmental grasteep topography on deep, silty soils, that developed from dients change continuously with gradual change in the density material derived from chalky limestone. The Geary-Holdregeof each species” (Poole 1974). The above idea was expressed Kipson is the major soil association. Weaver and Bruner (1948) by Ramenskylin 1910 (Sobolev and Utekhim, in Whittaker and Hopkins (195 1) studied the vegetation of the loess hills in 1973). However, Gleason (1917, 1929, and 1939) was the first the central part of Nebraska. Remnant vegetation of the loessial strong advocate of the continuum, or individualistic concept. region in southern Nebraska was characterized by Hulett et al. Most ecologists reportedly accept the continuum concept (1968) and Nicholson and Hulett (1969). (Poole 1974); however, others envision communities to be The Soil Conservation Service was asked to perform a range sufficiently distinct from one another that they can be thought of inventory in June 1976 in which two range sites were classified: as quasi-organism (Clements 1916; Tansley 1920). A somewhat silty (120 ha) and shallow limy (124). Range conditions for the more modulated view of communities recognizes that discersilty and shallow limy sites were conservatively rated at 1.1 nible community zones exist, while the flora of the earth AUM/ha (fair) and 1.2 AUM/ha (good), respectively, for a total exhibits a continuum (Daubenmire 1966). The placement of carrying capacity of 281 AUM. vegetation stands into classes has been referred to as the Arithmetic means were calculated from weather data obclassification concept. tained between 192 1 and 1950 at Red Cloud, Nebraska (NationAmong the first to base research on the continuum concept al Oceanic and Atmospheric Administration 1974). The mean were Curtis and McIntosh (1951), Brown and Curtis (1952), monthly low temperature of -3.2”C occurs in January; the mean monthly high temperature of 26.6”C occurs in July. The Authors are associate professor of botany, Fort Hays State University, Hays, Kansas 67601; and range conservationist, Bureau of Indian Affairs, Eagle Butte, South Dakota mean annual temperature and precipitation are 11.7” and 58.37 576X. This research was financially supported primarily by a grant from Woods Charitable cm, respectively. June is the month with the highest mean Foundation through the Midwest Office of the Nature Conservancy, Minneapolis, monthly precipitation total, with 10.16 cm; January has the least Minnesota. Additional renumeration was also received from the Research Committee of the Graduate Council and the Department of Biological Sciences, Fort Hays State monthly mean with 1.47 cm. The most frequent date of last University, Hays Kans. spring freeze is May 1, whereas the first fall freeze is most often Manuscript received July 11, 1977. October 4; thus the mean growing season is 156 days. 104 JOURNAL OF RANGE MANAGEMENT32(2), March 1979 In 1974, the study area was purchased by the Nature Conservancy as a memorial to Willa Carther; and during the 1975 and 1976 seasons, livestock grazing was discontinued. This study and several others were conducted to establish baseline ecological data to aid in future management and to allow documentation of vegetation changes. Resampling is_ tentatively scheduled for 1980, following several seasons of grazing, burning, and rest. Table 1. Eighteen herbaceous species used in the data analysis. Species common name Species scientific name Mean % sp camp