Matthew Bakker - The effects of burning and topographic position on infection by Fusarium spp. in three prairie forbs. (Mentor: Karen Garrett) 
Ecologists have not given adequate emphasis to the role of plant diseases in natural systems. Pathogenic fungi are no exception and while plant pathogens in the genus Fusarium have been studied extensively in agricultural contexts, they have received almost no attention in prairie systems. This study examined the rate of infection by Fusarium spp. in the roots of three prairie forbs (Solidago canadensis, Lespedeza capitata, and Asclepias verticillata). The effects of topography and burning frequency were also considered. Root samples were collected at the Konza Prairie Biological Station, from upland and lowland sites in ungrazed prairie watersheds which had either been burned annually for approximately 20 years, or that had been unburned for an equal period. Surface sterilized, milled root samples were combined with a modified Nash-Snyder semi-selective media and the number of colony forming units per gram of dry root material was determined after 7-10 days of growth. Rates of infection seemed to vary more by environment (combinations of topography and burning frequency) than by host plant. When the data was grouped according to host plant species, significant differences were not detected. However, for Asclepias verticillata and Lespedeza capitata, the rate of infection was significantly higher in annually burned uplands than in either unburned uplands or unburned lowlands (p < 0.05). A clear trend (p = 0.056) of higher infection rates in annually burned sites was observed. This seems counterintuitive, as fire might be expected to destroy disease inoculum, but may be explained by the limited nature of the direct effects of fire below the soil surface. Changes in soil moisture and plant community composition due to frequent fires are likely important. The growth of single spore isolates is still in progress, and should allow for interesting comparisons of the relative abundance of various Fusarium species.

Elizabeth Bockman - Above and belowground vegetation characteristics in native and restored tallgrass prairie. (Mentors: Gail Wilson and David Hartnett) 
Within the contiguous US, tallgrass prairie once extended from Kansas to Ohio and Texas to Canada, but today  < 4% of this once expansive grassland remains. Attempts to restore agricultural land back to tallgrass prairie have been met with varying degrees of success, and little research has been conducted to assess the recovery rates and trajectories of different components of the structure and function of these ecosystems. This study examined aboveground characteristics (plant productivity and species richness) and belowground parameters (mycorrhizal colonization, and rhizome and bud bank densities) to assess the recovery of five tallgrass prairie restoration sites varying in age from 1 to 25 years since initiation of restoration.  Arbuscular mycorrhizal fungi are ubiquitous in tallgrass prairies and form a symbiosis with most prairie plants. These fungi aid in phosphorus acquisition, improve water relations and increase disease resistance. Additionally, their external hyphae increase soil macroaggregate formation, which can control erosion and increase root penetration.   Belowground meristem populations (rhizome bud banks) are important in tallgrass prairie because aboveground plant populations and vegetation dynamics are strongly driven by vegetative rather than seed reproduction, as seedling establishment is rare due to high competition and low resource availability.  Thus, soil bud banks strongly regulate aboveground population dynamics and primary productivity.  Plant species richness and biomass were significantly lower in restored sites relative to native; this difference may be driven by differences in forb abundance as forbs were relatively rare in all restored sites. In this study, mycorrhizal colonization was significantly lower in restored relative to native sites. The lower colonization in the restored sites may be a response to shifting limiting resources, particularly P:N ratios. Grass bud bank densities were not different between restored and native sites. The ratio of belowground buds:stems, an index of meristem limitation, indicated higher demographic potential in native sites relative to restored. This meristem limitation in restored sites may also account for lower productivity in restored sites.

Isaac Deal - Life history and mark-recapture analysis of the Regal Fritillary (Speyeria idalia Drury) at Konza Prairie, Kansas.  (Mentor: Brett Sandercock).  
Regal Fritillaries are butterflies associated with native North-American prairies. Historically, these insects ranged from the Midwest to the East Coast. Their range has shrunken to about one quarter of that size and is now almost wholly confined to the Midwest. Regal Fritillary larvae rely on host plants that are sensitive to changes in the vegetative structure of the prairie. The sensitivity of the Regal Fritillary’s host plants makes the presence of the butterfly an indicator of pristine prairie. A population study was conducted on the Regal Fritillaries utilizing mark-recapture methods in order to identify trends in the population in response to variables such as time of year and burn treatment. The study was conducted at Konza Prairie Biological Station. Two watersheds were assessed, one was burned on a 4-year basis (N4C), the other was less frequently burned (N20A). Both watersheds were grazed by native bison (Bison bison). Within each watershed, three sampling sectors were established, each sector being a circle 200m in diameter. Butterflies were caught by a hand net and each was given an individual mark with a black Sharpie^® marker prior to release. Time of capture, location (GPS), sex, behavior, and wing wear were recorded for captured butterflies. A total of 375 individuals were captured and marked in the study, with 47 recaptures. Mean linear distance traveled by recaptured butterflies between their first and last capture coordinate was 90.0 meters among males and 50.6 meters among females. Male Regal Fritillaries were found to have a flight season lasting approximately one and one-half months from early June to mid July. Females emerged by mid June and persisted through the end of the study period in mid July. Data collected in the study indicates that Regal Fritillaries are univoltine. Residency of Regal Fritillaries in the sample sites was estimated to be short. Analysis of the data by use of a duration decay curve resulted in a mean residency estimate of 7.7 days with a range of 4.8 to 19.1 days. Analysis of the data by the use of mark-recapture models resulted in a mean residency of 6.4 days with a range of 3.9 to 10.9 days.

James Eckberg - Effects of altered rainfall patterns on C₃ tallgrass prairie communities. (Mentors: Jesse Nippert and Alan Knapp).
General circulation models predict that greater surface temperatures will increase rainfall variability.  The Rainfall Manipulation Plots (RaMPs) were established in 1997 to assess the effects of increased rainfall variability on intact tallgrass prairie plant communities by increasing intervals between rainfall events.  RaMPs results show that increased rainfall variability decreased productivity, primarily in C₄ grasses, and increased C₃ diversity.  Changes in C₃ diversity may be impacted by differential water stress and insect herbivory responses.  In this study, we examined insect herbivory and water stress in the RaMPs.  To illuminate water stress and herbivory effects in the RaMPs, the irrigation transects were sampled to provide baseline data for comparison.  The isotopic signature of carbon (d¹³C) was determined using an EA-IRMS.  This procedure allowed us to assess water use efficiency (water stress) in six C₃ species representing three growth forms; shrub, forb and grass.  Insect herbivory was visually assessed.  d¹³C analysis in the irrigation transects showed no treatment effects between irrigated and control.  This may be due to no difference in water availability between the irrigated and control prior to sampling.  Younger leaves had water use efficiency (higher d¹³C) than older leaves.  There were different water use efficiencies between species.  Solidago canadensis herbivory was higher in the delay versus ambient (Kruskal Wallis p<0.05) and control versus irrigated during June and July.  Higher herbivory in the drier treatments (delay and control) support that water stress increases herbivory response.  All other species showed no herbivory trends within the irrigation transects or RaMPs.  In turn, C₃ community composition may be responding to differential water stress and herbivory.  Percent cover of xeric late season species (Aster ericoides) was higher in delay relative to ambient treatments.  Percent cover of the moderately water use efficient, early season Dicanthelium oliganthes was not affected by the delay treatment.  Conversely, the low water use efficient, late season Solidago Canadensis was affected negatively by the delay treatment.  In conclusion, differential water stress and herbivory responses may be an important part of predicting C₃ community changes under altered rainfall patterns.

Courtney Franssen - Effects of barriers on the distribution and movement of prairie stream fishes after a flood. (Mentor: Keith Gido).
Prairie streams undergo harsh environmental conditions, thus fish must either be tolerant of these conditions or able to move into refugia habitats.  Moreover, ephemeral habitats in prairie streams may provide abundant resources, but fish must also move to access these areas.  Thus, to understand the dynamics of prairie stream fish assemblages we must understand movement patterns.  Because floods increase connectivity of intermittent habitats and barrier permeability, fishes would be expected to move during high water periods.  We marked four species of prairie stream fishes (Semotilus atromaculatus, Campostoma anomalum, Phoxinus erythrogaster, Etheostoma spectabile) in Kings Creek on the Konza Prairie Biological Station, Kansas.  Four hundred fish were batch marked with a subcutaneous injection of one of three site-specific colors of acrylic paint.  Marked fish were returned to the stream on both the upstream and downstream side of  three barriers four days prior to a flood that resulted in a 30-fold increase in discharge.  In the week following the flood, a five km reach of the stream was sampled by backpack electrofishing to monitor movement.  Most marked fish were found within 100 m downstream of their release point.  Semotilus  atromaculatus were found as far as 0.5 km downstream of their release point.  Although most movement was downstream, one C. anomalum moved nearly a kilometer upstream.  Our ability to follow movements of fish after natural disturbances has increased our understanding of how floods interact with prairie fish dynamics.

Sarah Haller - Pollination ecology of Lespedeza (Fabaceae): a native and an invasive.  (Mentor: Carolyn Ferguson).  
Four species of Lespedeza occur on Konza Prairie Biological Station (KPBS).  While three of these species are natives, one is an introduced perennial native to Asia and Australia.  Used extensively for forage crop, erosion control, and wildlife habitat, Lespedeza cuneata (Dumont) G. Don (“sericea lespedeza”) is now considered a noxious weed in many states including Kansas.  Knowledge regarding pollination and breeding systems in this species as well as in other Lespedeza species is needed not only to better understand reproduction in L. cuneata, but also to assess the potential for hybridization between native and non-native Lespedeza species.  A thorough pollination study was designed and implemented for the non-native Lespedeza cuneata and the native Lespedeza capitata Michx. focusing on 1) visitor observations 2) pollinator effectiveness and 3) breeding system.  Three study sites were chosen, KPBS (L. capitata), Ashland Bottoms (L. cuneata) and Ft. Riley Military Reservation (where both species are abundant and co-occur).  Netting of inflorescences was carried out to obtain virgin flowers for the pollinator effectiveness trials, and whole plants were caged as part of the breeding system study.  Data collection and analysis are ongoing; final data will be collected following all seed set in September or October.

Dustin Jasken -  Effects of fire and grazing on belowground architecture and vegetative reproduction in tallgrass prairie perennials. (Mentors: David Hartnett and Gail Wilson).
Plant population dynamics in tallgrass prairie are strongly driven by patterns of vegetative reproduction, as successful establishment from seed is rare and episodic.  Belowground meristem populations (rhizome bud bank) may also play an important role in regulating aboveground primary production and vegetation structure. The objectives of this study were to: 1) examine variation in belowground architecture (rhizome length and diameter) and vegetative reproduction (rhizome bud demography) among six tallgrass prairie perennial plant species, and 2) to assess the effects of key ecological processes (fire and grazing) on belowground architecture and demography. Rhizome systems were excavated from approximately .05 m² areas surrounding stems of Andropogon gerardii, Sorghastrum nutans, Andropogon scoparius, Koeleria pyrimidata, Solidago canadensis and Vernonia baldwinii between June 10 and June 25.  Plants were sampled in the following treatments; grazed/annually burned, ungrazed/annually burned, and ungrazed/four-year burn.  Rhizome architecture and demography was determined by measuring the previous years rhizome length and diameter, and counting new (current season) rhizomes and rhizome buds.  There was a significant effect on  belowground architecture due to fire frequency for only two species, S. nutans and S. candensis. Similar architectural responses to fire and grazing were observed for S. nutans and A. gerardii.  Significant effects of fire and grazing on total meristem production occurred in all species except  K. pyrimidata and V. baldwinii.  This study suggests greater variability in belowground architecture exists between species than between treatments (fire frequency and grazing). Belowground demography was variable between both species and fire and grazing treatments.  Furthermore, the relative abundances and composition of aboveground vegetation in tallgrass prairie does not necessarily reflect belowground patterns of rhizome and bud densities. 

Elizabeth Murray - Territoriality in male Blanchard’s cricket frogs, Acris crepitans blanchardi.  (Mentor: Eva Horne).  
Many male animals expend energy to actively defend their territory from conspecific intruders.  When there are limited resources, males compete with each other, and may escalate conflicts into physical encounters.  Many anurans, including Acris crepitans blanchardi, use acoustic and visual signals in order to defend a territory and maintain spatial separation.  I focused on a population of Blanchard’s cricket frogs located at a permanent pond at Konza Prairie Biological Station, Riley County, Kansas.  Male cricket frogs were often site specific, rarely moving more than 0.5 m during a single night, and returning to the same general location on subsequent nights.  Overall, males congregated on land within the first meter of the water’s edge, and calling males remained an average of 0.5 m apart.  However, over time, they tended to move out into the pond as aquatic plants emerged and there was floating vegetation to sit on.  In manipulations where I removed cricket frogs from a m² plot, fewer frogs emigrated into the site the next night, and the ones that did had significantly smaller mass, implying that larger males have already established calling sites and have no need to invade a new area.  However, in staged laboratory encounters, size (SVL and mass) had no effect on call rates.  Cricket frogs appear to defend calling sites using both acoustic and visual signals, but the particular characteristics that determine dominance are unclear. 

Judd Patterson -  Analysis of soil properties six years after prairie restoration. (Mentor: John Blair).
The conversion of prairie soils to agricultural fields alters soil structure, and results in loss of stored carbon (C) and nitrogen (N). Although dominant plant species communities and aboveground processes can be restored quickly, the rate at which soil properties and nutrient pools recover after prairie restoration can be extremely slow.  This project looked at various soil properties, including bulk density, total C, total N, and mineralizable C to assess trends in the recovery of ecosystem properties six years after restoration. In addition to testing soil from restoration plots, soil from adjacent agricultural fields and native prairie was also analyzed.  We found that total soil C and N increased relative to levels in the agricultural field, but they were still 47% and 37% (respectively) below the levels found in native prairie.  In contrast to total C, we observed that mineralizable soil C recovered much quicker, and was comparable to native prairie within six years in some of the restoration treatments. When looking at bulk soil density, the restored prairie soil was much denser than native prairie and was not significantly different from the agricultural field. These results illustrate the complexity and variability inherent in prairie restoration. While some soil properties seem to have nearly recovered to native prairie levels in the span of six years, others may need significantly more time.

Beth Ross - The effect of prairie vole (Microtus ochrogaster) runways on tallgrass prairie. (Mentors: Aaron Reed and Don Kaufman).
In tallgrass prairie, large herbivores such as bison (Bos bison) play a critical role in increasing plant heterogeneity through herbivory and nitrogen deposition.  While much is known about herbivory by large ungulates in tallgrass prairie, less is known about the effects of small mammal herbivory.  This study was carried out during the summer of 2003 to determine the effects of Microtus ochrogaster runways on tallgrass prairie.  Vole densities were low relative to peak abundance in tallgrass prairie (mean= 72.8 voles/ha; range: 35.7-107.1).  I took two five centimeter soil cores within vole runways, on the edge of the runway, twenty-five centimeters from the center of the runway, and over two meters away from any runway in order to determine the concentrations of nitrate and ammonia in the soil.  Big bluestem (Andropogon gerardii) was harvested at the edge of runways, 25 cm from the center of runways, and over two meters away from runways and carbon to nitrogen ratios were found using a Carlo Erba.  Plant biomass also was measured using these same distances surrounding runways.  I found a significantly higher concentration of nitrate at the edge of the runway relative to samples taken two meters away from runways.  Ammonia concentrations were found to be highest 25 cm from runways, with a significant difference between runway and edge of runway samples compared to 25 cm samples.  There was no significant difference between C:N ratios in A. gerardii.  Biomass was found to differ significantly between samples collected along the runway and samples taken two meters away from runways.  The differences in ammonia concentrations found throughout micro-sites could be due to increased plant uptake of ammonia in relation to increased herbivory along runways.  Increased herbivory along runways could also be the cause of decreased biomass along runways.