Britta Culbertson. - The Effects of Campostoma anomalum and Orconectes neglectes on periphyton biomass (Mentor: Walter Dodds).
The effects of two algivorous grazers, Campostoma anomalum and Orconectes neglectes, were investigated in artificial stream channels at Konza Prairie. These two organisms were placed into stream channels according to their natural densities in Kings Creek. After two weeks, treatments with O. neglectes had less periphyton (P<0.08 ANOVA); those with C. anomalum were not significantly different from the controls. We observed less filamentous green algae when O. neglectes was present. The decrease in algal biomass may be the result of herbivory or physical disturbances. Further investigation involved the manipulation of C. anomalum density to determine if densities in the first experiment were simply too low to have an effect. Analyses of fecal material and algal species composition are in progress.

Christopher A. Desjardins. - Nutritional Analysis of Nymphs and Adults of Orthopterans (Arcididae and Tettigoniidae) of the Flint Hills Region of Kansas (Mentor: Robert Robel).
Nutritional analysies were conducted on nymphs and adults of five species of Acrididae and two species of Tettigoniidae to determine differences in the nutritional value of the different life stages. The nutritional attributes determined were protien, energy content, ash, calcium, phosphorous, potassium, fat, and crude fiber, with priority given in that order if not enough sample was available. The Orthopterans used in the study were collected on the Konza Prairie Research Natural Area over the months of June and July by sweepnetting. Results showed few differences between the various life stages, while there were greater differences between species, subfamilies, and families. Protein content did not change between different life stages, but energy content showed a general trend of increasing energy as the species progressed through the life stages. Calcium showed an increasing trend with age, while phosphorous showed a decreasing trend with age. Most of these differences are thought to be due to the growth of the Orthopterans.

Natalie Dubois. - Territorial Responses in Sympatric House Wren and Bewick's Wren Populations (Mentor: Dale Kennedy).
Both House Wrens and Bewick's Wrens are found in the gallery forests on Konza Prairie. Egg-tossing activities by unmatured male and pre-laying female House Wrens have been found to significantly decrease the reproductive success of Bewick's Wrens. Conspecific and interspecific territorial responses of both species were monitored by use of playback tapes at various nesting stages. Conspecific responses of House Wrens were significantly stronger than those of Bewick's Wrens. House Wrens reacted more aggressively to the song of conspecifics than to the song of Bewick's wrens. Conversely, Bewick's Wrens were more responsive to the song of the House Wrens than to their conspecific song. The aggressiveness of Bewick's Wrens to the songs of House Wrens may be a response to the nest vandalism by House Wrens.

Jason Hoeksema. - Response of Big Bluestem and Indian Grass to Interaction with an Introduced Grass, Caucasian Bluestem in Tallgrass Prairie (Mentor: David Hartnett).
Invasion of an introduced species, caucasian bluestem (Andropogon bladhii) provides an opportunity to investigate strategies of an invading species, the characteristics and responses of the native community being invaded, and the potential for the invading species to become established in the native community. We pursued these objectives with three experiments in an annually burned, ungrazed site in tallgrass prairie. For the first experiment, we measured the growth of A. bladhii clumps within an established, relatively monotypic stand of conspecifics, and also outside of these stands where A. bladhii is invading and is surrounded by native vegetation. The second experiment compared the growth of native grasses transplanted into a monospecific stand of A. bladhii compared with native grasses transplanted reciprocally into native vegetation. The third experiment measured the growth of native grasses at varying distances from A. bladhii clumps which had either been trimmed to ground level, killed with Roundup, or left untouched. Intraspecific competition was stronger than interspecific competition for A bladhii. Transplanted native grasses grew better with A. bladhii neighbors than with native neighbors. Native grasses grew better nearby control clumps of A. bladhii clumps than nearby trim or Roundup clumps. So at the individual level over a short time period, native grasses seem to grow better in the presence of the introduced grass. However, grazing could cause the negative effect of A. bladhii on native grasses to be much stronger.

Micah Kaufmann. - Distribution of Bison Wallows on a Tallgrass Prairie (Mentor: John Briggs).
The size and distribution pattern of American bison (Bos bison) wallows on a tallgrass prairie were examined on watershed N04D in July, 1995. 100 different wallows were mapped into a GIS (ARC/INFO). The size of the wallows ranged from 1 to 46 squared meters with an average of 8 squared meters (SE = 0.71m). Overall, the wallows were clumped in several clusters on relatively flat areas within the watershed. The average distance between all of the wallows was 708 meters (SE =5.6m ). Since these wallows were placed in a GIS, the long-term importance of these disturbances in the tallgrass prairie ecosystem can now be examined.

Stacy J. Morris. - The Effects of Predator Exclosures on the Nesting Success of Dickcissels (Mentor: John Cavitt).
Predation is the greatest source of mortality for open nesting birds. Previous studies suggest that snakes are major predators of birds on grasslands. The dickcissel, a ground nesting species that is abundant in tallgrass prairie, loses almost half of its nests to predation. Wire mesh enclosures were placed around dickcissel nests to determine their effect on nesting success. The daily survival rate, the date of nest initiation, and the proportion of eggs that became fledglings in enclosed nests and unenclosed nests were not significantly different. The clutch size of enclosed nests was significantly greater than that of unenclosed nests. Either snakes are not effectively precluded by these exclosures, snakes are not the primary predators of dickcissels, or the small sample size of this study is not representative of the community.

Jennifer A. Rudgers. - Comparison of the Reproductive Strategies of Three Milkweed Species (Mentor: Christopher Smith).
Inflorescence size may influence plant reproductive success as inflorescences of different numbers of flowers are likely to be differentially successful as pollen donors or recievers because they attract more pollinating vectors. Past studies have suggested that inflorescence size in Asclepias has evolved from selection acting on male reproductive success. To test this pollen donation hypothesis, A. viridis, A. tuberosa, and A. stenophylla were studied during their flowering and fruiting seasons on an annually burned watershed at Konza Prairie Research Natural Area, KS. Leaf morphology and photosynthetic capabilities were quantified as well, for the three species flower successively through the dramatically changing seasons of the tallgrass prairie. The number of pollinia removed was used to estimate male success and the number of pods produced to assess female success. The number of pollinia removed per flower was correlated with the number of flowers in A. viridis (p<0.008) and A. stenophylla (p<0.016). The number of pods per flower was negatively correlated with the size of inflorescence for A. viridis (Spearman r = 0.38, p<0.03). These results support the pollen donation hypothesis. Inflorescence size is also bound phenotypically to the availability of resources. Leaf area and number of leaves were significantly correlated with the number of flowers per plant for A. viridis and A. tuberosa. This correlation did not result for A. stenophylla largely because, unlike A. viridis and A. tuberosa, A. stenophylla did not vary in the number of stems per plant. Photosynthetic capacity differences were discovered between species. A. stenophylla, the last of the three to flower had a higher photosynthetic capacity at higher levels suggesting an adaptation to water stress in late summer.

Erik Sparling - Single Plant Species Effects on Carbon and Nitrogen Cycling and Microbial Populations in the Tallgrass Prairie (Mentor: Charles Rice).
Plant community structure is important in nutrient cycling. We examined the importance of single plant species on C and N cycling by looking at microbial biomass and activity in soil beneath five common tallgrass prairie plant species. Soil microbial biomass C and N varied significantly beneath some species. Of all measured microbial parameters, soil respiration rates were most frequently affected by dominant plant species differences. Mineralization rates were also different beneath some plant species. Additional measurements and correlation analysis suggested that the plant above ground biomass C and N content differences, as well as below ground biomass differences, may be some of the most important factors regulating microbial population size and activity.

Heather Throop. - Impacts of Fire and Herbivory on Ceanothus herbaceous Architecture and Reproduction (Mentor: Phil Fay).
Fire and herbivory can both be major causes of damage and mortality to woody plants in grassland environments. Ceanothus herbaceous (New Jersey Tea), a prevelant species in Flint Hills tallgrass prairies, experiences herbivory through deer (Odocoileus spp.) browsing and stem galling by the moth Periploca ceanothiella. The relative impacts and interactions between galling, deer browsing, and fire on C. herbaceous growth and architecture were investigated by comparing numbers of shoots, buds, and inflorescences; bud vitality; and herbivory rates between plants on an annually burned and an infrequently burned watershed. Fire had very strong effects on C. herbaceous growth patterns, reducing the number of shoots per ramet, increasing ramets per plant and shoot length, and preventing sexual reproduction. The effects of herbivory were much weaker than those of fire. Galling rate was higher on the infrequently burned watershed. Galled ramets had shorter shoots but increased numbers of shoots and inflorescences than ungalled ramets. The browsing rate did not differ significantly between the two watersheds. Browsed ramets produced more inflorescences on both watersheds, fewer shoots per ramet in the annually burned watershed but more shoots per ramet in the infrequently burned watershed. Fire appears to be the major regulator of C. herbaceous population dynamics, through direct effects on architecture and reproduction, and by indirectly affecting the rates and consequences of herbivory.