Virginia Flanagin - The effect of nest site, grazing, and burning on the daily survival of artificial nests (Mentor: John Cavitt).
Predation is the major cause of nest failure on the tallgrass prairie. Current land management practices such as cattle grazing and annual burning may increase predation rates, causing the population declines seen among species that breed on the tallgrass prairie. High predation may also be due to the low structural diversity of vegetation in prairie ecosystems, which limits nest site selection. Artificial nests were placed along transects in eleven watersheds on Konza Prairie Biological Station to measure the relative rates of predation between combinations of burned and grazed land treatments. Nests were placed either in the bush or under forbs on the ground to compare predation between the two types of nest locations that exist on the prairie. The results also suggest that burning decreases daily survival, whereas grazing increases the daily survival rates. These results are contrary to data obtained from real nests. However, heterogeneity of vegetation is higher in grazed sites and lower in burned sites. Hence, the predators may be more capable of developing a search image for nests in burned ungrazed sites because forbs are less diverse and at a lower density in these watersheds.

Nathan Heavers - The effects of cattle ranching on the Dewey Ranch Ecosystem (Mentor: Jim Sherow).
The Dewey Ranch, south of Manhattan, Kansas, was part of a rich cultural and ecological history of cattle grazing in the Flint Hills. Changes in cattle management practices on the Dewey Ranch between 1930 and 1977 had a critical impact on the ecosystem. The ranch ecosystem consisted of all the geographic features of the area including climate, soil quality, water availability, and fire, as well as biological components, such as vegetation, cattle, and man. Man’s interactions within the ecosystem are the focus of this historical analysis which considers both culture and developing technology as ecological factors. In reconstructing the history of the Dewey Ranch, it is apparent that man was a central figure in this ecosystem and the cattle management practices he employed resulted in ecological change.

Mary Jamieson - Pollen-Ovule Ratios and Breeding Systems of Prairie Forbs (Mentor: Christopher Smith).
Plant mating systems control patterns of gene flow and thus genetics variation of plant populations. Self-fertilization has evolved repeatedly in the plant kingdom despite the pressures of inbreeding depression. This phenomenon, in particular has created great interest in understanding the evolution of plant breeding systems. Many studies attempt to elucidate the mechanisms of pollination biology and to describe the dynamics and components of plant reproduction. One aspect of plant mating systems that has been widely studied is the pollen-ovule ratio of plants. Two non-mutually exclusive theories exist regarding the relationship of P/O and plant breeding systems (Cruden 1977 and Charnov 1982). Our study examines the correlation of P/O and the breeding systems of 20 selected species of forbs on the Konza prairie. P/O was quantified by counting pollen grains with a haemacytometer and ovules under a dissecting scope in a solution of aniline-blue in lactophenol. P/O was then compared to outcrossing indices determined in an earlier study (Townsend 1984). Using Spearman’s rank correlation it was shown that no significant correlation exists in species across phylogenetic groups (r=0.200; N=20;p<0.05). However, supporting both Cruden’s and Charnov’s hypotheses regarding closely related taxa, P/O was shown to be negatively correlated with outcrossing indices of species within tested families. Thus, P/O may be a useful tool to assess plant mating systems within monophyletic groups.

Amanda J. López - Nutrient Uptake in Prairie Streams (Mentor: Walter Dodds).
Understanding nutrient dynamics in streams is an important aspect of study of aquatic nutrient pollution. Nutrient uptake studies were conducted in a prairie reach and a gallery forest reach of King’s Creek on the Konza Prairie Biological Station. Nutrient uptake rates and uptake lengths were measured with several short-term additions of nitrate, ammonium or phosphate at constant release rates in the spring and summer of 1998. A conservative tracer of sodium bromide was used to account for biotic dilution. Linear regression was used to fit uptake rates. The results from different concentrations were used to determine whether the uptake was limited by the biotic capacity of microorganisms to accumulate nutrients, or by the stream’s physical characteristics (including limitation by hydrological transport into stream biofilms). Our results demonstrate that uptake rates can be saturated, indicating limitation by hydrological transport can be exceeded at high nutrient concentrations in the stream. However, the absolute concentration that uptake was saturated at varied among reaches and nutrients.

Jennifer Nelson - Indirect Interspecific Interactions: Average Interaction Strengths of Indirect Interaction Chains (Mentor: Walter Dodds).
Interactions among species shape and structure communities. When looking at a community, one can see that there are a large number of possible direct interactions among species. Moreover, some species can have profound impacts on other species with whom they do not interact directly. How important are these indirect interactions in general? For this study, I looked at the average interaction strength for direct, and indirect interaction chains of various lengths. Direct interaction strengths were determined from published community matrices. Interaction chains were made with "links" provided by direct interactions. Each link species appeared only once in each chain. In general, the average strength of the interaction chain decreased with increasing number of links in the chain. In communities dominated by negative interactions, (i.e. competition) a positive indirect interaction offset the negative direct interactions.

Tanya Smutka - Food Habits and Predation Rates of Creek Chubs (Mentor: Christopher Guy).
The purpose of this study was two-fold; (1) to determine the food habits of creek chubs, and (2) determine predation rates of creek chubs and largemouth bass on southern redbelly dace. Creek chubs were collected from Four Mile Creek on Fort Riley and from Kings Creek on Konza Prairie. Food habits of creek chubs collected from Four Mile Creek consisted of aquatic invertebrates (71%; mean percent composition), terrestrial invertebrates (15%) and unidentified invertebrates (15%). However, the diet of creek chubs from Kings Creek consisted of more terrestrial invertebrates (73%) than aquatic invertebrates (27%). In the laboratory predation study, largemouth bass had a significantly higher (P<0.0001; mean = 2.8) piscivory rate (number of southern redbelly dace per day) than creek chubs (mean = 0.5). The difference in food habits between these two populations may be due to differences in the fish assemblage between the creeks. Although no fish were found in the food habits data of creek chubs collected from Four Mile and Kings Creeks, creek chubs did exhibit piscivory in the laboratory experiment. However, the impacts of piscivory on stream fish communities by largemouth bass are likely greater than creek chubs.

Shawn Papon - Nutrient Contents of Invertebrates on Different Sites (Mentor: Robert Robel).
Invertebrate biomass commonly comprises over half of the dietary intake of breeding grassland birds. The nutrient content of this invertebrate forage base for birds differs by taxonomic category and site. One of the reasons proposed to explain the differences in nutrient contents of invertebrates from different sites was the food substrate quality of the invertebrates collected. To test this hypothesis we collected invertebrates from sites of different soil fertility (determined by total C and N content) and compared the nutrient contents of those collections. Pitfall traps were used to capture invertebrates from annually burned and 6-yr burned sites on the Konza Prairie Biological Station in eastern Kansas and from a sand sagebrush site in southwestern Kansas. Representatives of Carabidae, Gryllidae, and Acrididae were separated from the invertebrate collections and analyzed for nutrient content. Total C and N contents in soil samples from the southwestern Kansas site were significantly lower (p<0.05) than those from eastern Kansas sites; total C and N in soils of annually burned sites were not significantly different than those of 6-yr burned sites. Total C contents of invertebrates were significantly higher on Konza, and total N (crude protein) contents of the herbivorous invertebrates, i.e., Gryllidae and Acrididae, were significantly higher in more fertile sites. Data collected in this study indicate that the site-related differences reported earlier in nutrient and energy contents of invertebrates.

Sophie Parker - Dogs as Models in the Study of Predator Olfaction (Mentor: Phil Gipson).
Standardized odor attractant tablets are often used as tools in the study of predator ecology, particularly with scent stations to assess mammalian predator populations. Despite their frequent use, little has been done to determine how far predators can smell these tablets, or how the distance of first detection varies with changes in weather conditions. Two male Australian Shepherds and one female Samoyed, all obedience and agility trained, were used to study how far standard odor attractant tablets can be detected. The greatest downwind distance a test dog was able to detect odor from a tablet was 1029 meters. This occurred with 85% relative humidity, an air temperature of 74°F, and a slight breeze (<1 mph). The shortest downwind distance at which a test dog detected the odor was 470 meters. This occurred on a morning with 90% relative humidity, an air temperature of 66°F, and no wind. The average distance from the tablet at first detection over ten trial runs was 829 meters. Changes in the dogs’ first detection distances appear to be correlated with wind and other weather conditions. This information may aid researches in estimating the distances from which wild predators could be attracted to scent stations.

Natali E. West - The Effect of Bison Grazing on Soil Respiration on the Konza Prairie (Mentor: Loretta Johnson).
It has recently been thought that large mammals such as bison have substantial influence over ecosystem processes such as nutrient cycling and may serve as a keystone species on tallgrass prairies. The focus of this research was to explore the effects of bison grazing on soil respiration. Data indicates that grasses often preferentially allocate carbon resources for aboveground growth following defoliation (or grazing); it was therefore hypothesized that soil respiration would decline under grazed conditions. The N4D grazing lawn on the Konza Prairie served as the study site. Soil respiration measurements were made using a Licor 6200 Photosynthesis System. Measurements were made both in the grazing lawn itself and in ungrazed enclosures assembled on the study site. Soil temperature and moisture were measured simultaneously with respiration. Microbial respiration under moderately and heavily grazed conditions was also analyzed through controlled incubations. Results indicated that bison grazing did significantly decrease soil respiration and significantly increase soil temperature, but had no significant effects on soil moisture or microbial respiration.

Charmaine Woodard - Abundance and Diversity of Burying Beetles (Silphidae) on Konza Prairie (Mentor: David Rintoul).
The burying beetles of Konza Prairie Research Natural were surveyed for their seasonality and diversity, as well as any possible preference for watersheds varying in burn frequency from one to 20 years. Seven pitfall traps on three sites were employed. The possibility of finding the endangered species, Nicrophorus americanus, may also exist, so appropriate precautions were taken in case of this event.