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A factorial field experiment was designed to test the effects of small mammals and above- and below-ground invertebrates on plant species richness and composition in native tallgrass prairie at Konza Prairie Research Natural Area, northeast Kansas. Over a 4-year period, Microtus ochrogaster densities were maintained by live-trapping in fenced plots, and invertebrate levels were reduced using the pesticides carbaryl for above-ground invertebrates and an organophosphate (isofenphos) for belowground invertebrates. ANOVA according to a split-plot design of plant species biomass data harvested in 1984 and 1986 revealed few significant effects of either small mammal densities or pesticide application. Of 54 species harvested from both sample dates, only 10 were significantly affected by either treatment. Analysis of species richness according to 8 life-form classes provided a clearer pattern of response than did biomass either by species or life-form class. For example, numbers of C4 grasses were reduced by increasing small mammal densities, whereas numbers of C4 annual forbs were lowest when above-ground herbivory was reduced. While consumers have been shown to have strong effects on successional communities, the few significant results observed in this study suggests that the manipulated levels of small mammals and insects had few effects on a mature tallgrass prairie.

Native unploughed tallgrass prairie from Konza Prairie, Kansas, USA is described with respect to plant species compositional changes over a five year period in response to fire and topography. The principal gradient of variation in the vegetation is related to time since burning. Species show an individualistic response in terms of relative abundance to this gradient. Both the percentage of and cover of C4 species and all grasses decrease as the prairie remains unburnt. Forb and woody plant species numbers and abundance increase along this gradient. A secondary gradient of variation reflects topography (i.e. upland versus lowland soils). Upland soils support a higher species richness and diversity. Upland and lowland plant assemblages are distinct except on annually burnt prairie. The interaction between burning regime, topography and year-to-year climatic variation affects the relative abundance of the plant species differentially. The most dominant species overall, Andropogon gerardii, was affected only by year-to-year variation (i.e. climate). Its position at the top of the species abundance hierarchy was unaffected by burning regime or soil type. The other dominant species showed a suite of varying responses to these factors.

Eleven experimental treatments were applied to 2 x 2 m plots over 2 yr at Konza Prairie Research Natural Area, Riley County, Kansas, to ascertain why burning tallgrass prairie causes increased production and flowering. Warming of the soil in unburned plots resulted in an increase in both total production and flower stalk production of dom- inant tall grasses, primarily big bluestem (Andropogon gerardii) and Indian grass (Sor- ghastrum nutans), but the increase was small (34% increase in biomass; 78% increase in number of flower stalks) compared with that in burned plots (151 /% increase in biomass; 435% increase in flower stalks). Increased surface light intensity also appears to be a factor affecting changes in productivity following burning as suggested by the combined responses of increased productivity with removal of standing dead, whether by clipping or burning, and decreased productivity with shading. Further, the addition of ammonium nitrate in- creased yield 41 % and flowering 168% for the dominant grasses, suggesting that any factor increasing nitrogen availability would affect these vegetative parameters. Neither ash left from burning nor heating of the soil surface during burning produced detectable effects on subsequent vegetative growth. Different results for some parameters between years and between species suggest that many complex interactions operate to affect the grassland's response to burning, but surface light, soil surface temperature, and nitrogen appear to be particularly important factors.

Two— by two—meter plots of undisturbed, nearly pure Andropogon gerardi prairie were subjected to four treatments: burning, clipping and removal of the litter, burning the clipped litter and returning the ash, and the control (natural litter). Treatments were started in early April before growth began. Differences in results among the denuded plots were small and nonsignificant, but highly significant differences were found between denuded and control plots. Tiller number was increased 1.5 to 2.7 times by removal of litter. Growth began earlier in denuded than control plots. On May 31 yields were twice as great in denuded as in control plots. On September 1 ovendry yields were about 340 g/m2 in denuded and 180 in control plots. Soil temperatures were 1°/5°C higher in denuded than control plots the entire growing season, the differences lessening as the season progressed. Soil moisture was appreciably higher in control plots the entire season. The short—term effects of spring burning in undisturbed bluestem prairie with clay—loam soils are apparently related primarily to litter removal rather than to nutrient changes.

The Konza Prairie Research Natural Area is a 3487 hectare research area located in the northern Kansas Flint Hills. The vegetation of Konza Prairie is predominantly tallgrass prairie with limited gallery forests along major tributaries. The vascular flora of the research area includes 441 species in 90 families. This number represents approximately 44% of the species known to occur in the Kansas Flint Hills. Konza Prairie Research Natural Area (KPRNA) is located in the northern part of the Kansas Flint Hills. This 3487 ha (8616 acre) area is situated approximately 10 kilometers south of Kansas State University in Manhattan, Kansas. Most of the area is in extreme southcentral Riley County, the rest in adjacent Geary County. KPRNA is bounded on the east by Kansas Highway 177 and on the south by Interstate 70. Konza Prairie was acquired by The Nature Conservancy, a national nonprofit private organization dedicated to the preservation of lands exemplary of diversity in the natural world. The Geary County portion, called the original Konza Prairie, consists of 371 ha (917 acres) and was purchased in December 1971 (Fig. 1). In January of 1977, the 2921 ha (7219 acre) Dewey Ranch was added to the research area. A final acquisition was made by The Nature Conservancy in December 1977, when the 194 ha (480 acre) Thowe tract was added to KPRNA. The land is leased to Kansas State University for ecological research. Konza Prairie is one of eleven Long-Term Ecological Research (LTER) sites across the United States supported by the Division of Environmental Biology of the National Science Foundation. Konza Prairie is representative of the Flint Hills Upland, a band of rolling hills roughly 70 kilometers wide extending across Kansas from near the Nebraska-Kansas border south to Oklahoma. The hills were formed by the Contribution No. 83-74-j, Division of Biology, Kansas Agricultural Experiment Station, Manhattan. This content downloaded from 207.46.13.162 on Fri, 01 Jul 2016 04:08:27 UTC All use subject to http://about.jstor.org/terms VOLUME 88, NUMBERS 3-4 85 KONZA PRAIRIE RESEARCH NATURAL AREA 1 4e

response of height to fire was variable. In contrast, density and production of flower stalks were usually greater on the annually burned sites, whereas soil effects were inconsistent. Production of flower stalks for all three species combined ranged from 0 to 670 g/m2 during the 4-year period with maximum production occurring in a mesic year which followed a drought year. Various estimates of net primary production (aboveground biomass) have been used as ecological descriptors of grassland ecosystems throughout the world. Variations in aboveground productivity among grasslands in North America may range from 0 to 1000 g/m2/yr but within grassland types

From l April to 26 August 1978, about 45 percent of the aboveground standing dead plant material and litter disappeared in ungrazed bluestem prairie on Konza Prairie Research Natural Area, Geary County, Kansas, USA. In plots trampled on April l to compact the material close to the soil surface about 55 percent of the material decomposed. The results are based on 10 replications in native prairie on deep, productive, silty-clay loam at two sites, l and 5 years since burning. The amount of decomposition of aboveground standing dead plant material and litter was studied on the southern part of Konza Prairie Research Natural Area, 14 km south of Manhattan, Kansas at the north edge of Geary County. The study was begun in the spring of 1978 on two sites, one last burned in the spring of 1973, the other last burned in the spring of 1977, or 5 and l years since burning. Both were on lower slopes with Tully silty-clay loam, 4 to 8 percent slope. This soil is deep, not rocky, moderately permeable, and representative of the productive bluestem prairie soils that support grasses 2 meters tall in good years. The 108-year median precipitation at nearby Manhattan is 779 mm. In March, 1978, 50 plots, each 0.5 by 1.5 meters, were marked in a block in each of the two sites and two treatments were instituted: trampled and control. All plots were randomly selected. Ten plots in each site were sampled on April 1 to obtain the initial weight of above ground organic matter. At the same time the standing dead plant material was compacted on 20 plots at each site by breaking stems by hand and by walking on the plots until the material lay close to the soil surface. 1 Contribution No. 80-73-J, Division of Biology and Kansas Agricultural Experiment Station. This content downloaded from 157.55.39.78 on Sun, 19 Jun 2016 05:54:04 UTC All use subject to http://about.jstor.org/terms Table 1. Oven-dry weights (g/m2) and least signilicant differences (LSD) of standing dead plant material and litter at three dates on areas I year and 5 years since burning. Values in parentheses are percent loss in weight from the initial weights on I April. Averages of 10 plots, each 0.1 m2. I year since burning 5 years since burning Date of sampling Control Trampled Control Trampled I April 680 950 a* 5, 7 June 503 a (26) 382 ab (44) 884 a (7) 591 b (38) 26 August 383 ab (44) 334 b (51) 507 b (47) 332 (65) LSD, 59 102 LSD, 59 170 IC>o 136 1S, 228 * Values for each of the two treatments followed by the same letter are not significantly different at the 5 percent level. Sampling was done in 20 by 50 cm (0.1 m2) plots by clipping as close to the soil surface as feasible, placing the standing dead and litter in a paper sack, oven-drying at 60°C, and weighing. Production of the 1978 season was removed to the extent it could be distinguished. Separation was complete in June, but a small amount, probably insignificant to the current year's growth, may not have been removed in August. Approximately 2 and 4 months after the first sampling, 10 control plots and 10 trampled plots were sampled in each site at each date. Vacuuming was not employed, but care was taken to pick up as much organic matter on the soil surface as possible in these small plots. A little less than half the aboveground dead organic matter disappeared in the four months from April through August (Table 1). Trampling caused a significant increase in the amount decomposed. The increase is likely to have resulted from slower drying and perhaps from warmer temperatures than in the untrampled material. The few other studies that provide information on rate of decomposition in bluestem or tallgrass prairie also found that about half of the material disappeared during the growing season (Hadley and Kieckhefer, 1973; Kucera et al., 1967). The increased rate of decomposition resulting from trampling implies that compaction by snow speeds up decomposition. This should help compensate for the shorter decomposition season in the northern than in the southern part of the bluestem prairieX and is a factor in the variation in amount of aboveground dead organic matter from year to year. The trampling effect also implies that trampling by livestock would increase decomposition, but this effect would be complicated by changes in the amount of material entering the standing dead plant material and litter 34 compartments of the ecosystem (Sims and Singh, 1978). TRANSACTIONS OF THE KANSAS ACADEMY OF SCIENCES This content downloaded from 157.55.39.78 on Sun, 19 Jun 2016 05:54:04 UTC All use subject to http://about.jstor.org/terms VOLUME 83, NUMBER 1 35

ment Station. This study supported by The Kansas Agricultural Experiment Station, also fulfilled a part of the requirement of the Ph.D. degree in plant ecology. ABSTRACT. On the Republican River floodplain in Clay County, Kansas, 39 forest stands were plot sampled in 1968. Salix interior (sandbar willow), S. amyg- daloides (almondleaf willow), and Populus deltoides (cottonwood) appeared the first or second year after alluvium was exposed above water level. Salix interior rarely persisted more than 10 years, S. amygdaloides not more than 30 years, and P. deltoides about a century. Young of these species did not survive in established stands. After about 100 years dominant trees included Ulmus americana (American elm), Celtis occidentalis (common hackberry), Fraxinus pensylvanica (green ash), Morus rubra (red mulberry), and Acer negundo (boxelder). No stand had attained climax, but Celtis occidentalis and Ulmus americana would likely have been dominants. Celtis may be the sole dominant in the future now that Dutch elm disease has en- tered the area. For young (0-10) and old (>60 years stands, mean tree density was 24,000/ha (9,710/acre) and 5,000/ha (2,020/acre), mean basal area was 20 m2/ha (87 ft2/ acre) and 39 m2/ha (170 ft2/acre) and mean basal area per tree > 6 cm diameter was 58 and 638 cm2, respectively. The amount of light that penetrated the forest capony ranged from 18% in young to 2% in old stands. Competition, especially ef- fects of shading, is thought to be more important than changes in soil in eliminating pioneer woody species. Polygonum lapathifolium, Ambrosia trifida and Conyza canadensis were the most common herbs in young stands. Galium aparine had a frequency of 20% in young stands and over 70% in stands more than 30 years old. Rhus radicans and Partheno- cissus quinquifolia were absent in young but common in old stands. Studies of floodplain forest succession provide knowledge that can be applied in managing timber, wildlife, recreation, and floods. Such forests in Kansas and nearby states have been little studied. In Kansas Schaffner (1906) referred briefly to river-bottom forests in Clay County; Smith (1940) to one 200-year old stand in the Smoky Hill Valley in Geary County; and Gesink, Tomanek and Hulett (1970)

As part of a long-term study of greater prairie chicken (Typanuchus cupido pinnatus) ecology in northeastern Kansas (Slade et al. 1965; Robe& 1966; Watt, 1969), an attempt was made to correlate movements and locations of prairie chickens with habitat types. In order to accomplish this, the various habitat types on a 2,500-hectare grassland study area had to be described. Species composition alone could not provide all the information necessary to evaluate the habitat potential of a grassland for prairie chickens. Emlen (1956) indicated that vegetation screening efficiency and density were as important as species present in describing avian habitats. Specifically, Hamerstrom et al. (1957) stated that height and density of grass were “clearly more important to the prairie chickens than species composition.” Various optical means have been used to measure the height and density of vegetation (Wight, 1938; Webb, 1942; Mossman, 1955).

The occurrence of cross timbers (Quercus-Andropogon) and bluestem prairie (Andropogon, Panicum, Sorghastrum) in relation to texture of surface layers of soils is presented for a township in Chautauqua County, Kansas. It is based on the unpublished soil survey of Chautauqua County by the U.S. Department of Agriculture, Soil Conservation Service, and vegetation data from aerial photographs, supplemented by extensive field observations while mapping the soils. On uncultivated portions of the township, cross timbers occur in 98% and prairie in 2% of the upland soils with moderately coarse-textured surface layers, whereas upland soils with medium to moderately fine-textured surface layers are 92% in bluestem prairie and 8% in cross timbers, which 'Contribution No. 1207, Division of Biology and Kansas Agricultural Experiment Station, KSU. Permission by the U.S. Department of Agriculture, Soil Conservation Service, to use parts of the unpublished Chautauqua County Soil Survey is gratefully acknowledged. 2Soil Scientist, U.S.D.A., Fort Scott. 3Professor, Div. Biology and Kans. Agric. Exp. Stat., Manhattan. Transactions of the Kansas Academy of Science, Vol. 77, No. 4, 1974. Published March 10, 1976.