01986nas a2200193 4500008004100000245012700041210006900168300001400237490000800251520130500259653002301564653003701587653003001624653003301654653002501687100001501712700001901727856004601746 2017 eng d00aDensity mediates grasshopper performance in response to temperature manipulation and spider predation in tallgrass prairie0 aDensity mediates grasshopper performance in response to temperat a261 - 2670 v1073 a

Species interactions are often context-dependent, where outcomes require an understanding of influences among multiple biotic and abiotic factors. However, it remains unclear how abiotic factors such as temperature combine with important biotic factors such as density-dependent food limitation and predation to influence species interactions. Using a native grassland - grasshopper - wolf spider model food chain in tallgrass prairie, we conducted a manipulative field experiment to examine how predator-prey interactions respond to manipulations of temperature, grasshopper density, and food chain length. We find that grasshopper performance responses to temperature and predator treatments were density dependent. At high densities, grasshopper survival decreased with increased temperature when no spiders were present. When spiders were present, grasshopper survival was reduced, and this effect was strongest in the cooled treatment. In contrast, grasshopper survival did not vary significantly with spider presence or among temperature treatments at low grasshopper densities. Our results indicate that context-dependent species interactions are common and highlight the importance of understanding how and when key biotic and abiotic factors combine to influence species interactions.

10adensity dependence10aKonza Prairie Biological Station10aPhoetaliotes nebrascensis10aRabidosa rabida; temperature10aSpecies interactions1 aLaws, A.N.1 aJoern, Anthony uhttps://doi.org/10.1017/S000748531600089404432nas a2200193 4500008004100000245014500041210006900186260004300255490002100298520366600319653003403985653002204019653003704041653003904078653002104117100002804138700001904166856005304185 2017 eng d00aRole of spatial and temporal vegetation heterogeneity from fire-grazing interactions to the assembly of tallgrass prairie spider communities0 aRole of spatial and temporal vegetation heterogeneity from fireg aManhattan, KSbKansas State University0 vPhD Dissertation3 a

North American tallgrass prairie is a dynamic ecosystem that evolved with variable regimes of fire and grazing interactions (pyric herbivory), and variable mid-continental weather. Combined, these ecological factors create a shifting mosaic of plant communities that create heterogeneous and structurally complex habitats that move around across the landscape in time and space. The overarching goal of my dissertation was to study how bottom-up habitat templates created in response to fire-grazing interactions influence the community structure of spiders, key arthropod predators in grassland food-webs. Spiders are a ubiquitous and diverse group of terrestrial predators that partition their habitat at fine scales with species distributions and abundances that are sensitive to habitat structure. Primary hypotheses examined include: (H1) Spider density, species diversity, species evenness and functional richness of hunting strategies should increase as the spatial heterogeneity of habitat structure and overall habitat productivity increases, as predicted by the habitat complexity and heterogeneity hypothesis. (H2) Pyric herbivory indirectly determines spider community structure through is effect on vegetation structure and spatial heterogeneity, thereby promoting the formation of a mosaic of spider species assemblages that track changes in the distribution of key habitat resources. My research takes advantage of a long-term, watershed-level manipulations of fire frequency and bison grazing across a topographically variable landscape at Kansas State University’s Konza Prairie Biological Station, a tallgrass prairie research site near Manhattan KS. Spider communities were sampled for three years at 23 sites representative of multiple habitat types ranging from low-stature grass-dominated sites to grassland-gallery forest transition zones. In addition, a field experiment was performed to test the hypothesis that vegetation structure contributes directly to web-builder abundance and web-type richness of spiders in open grasslands. Here, the availability of structure for web placement was increased by adding dead woody stems along transects in three watersheds that differed in burn histories and existing habitat structure in the absence of grazing. Results were consistent with the three key hypotheses. Species diversity and the functional diversity of spiders increased as the spatial heterogeneity and overall structure of habitat increased in response to fire-grazing interactions. Vegetation heterogeneity influenced spider community responses most strongly in the summer. Structural complexity of vegetation influenced spider diversity, species evenness and richness of hunting strategies throughout the growing season, becoming most important by the end of the growing season. The transitional ecotone between grasslands and woodlands supported a hotspot for spider density, species diversity and richness of hunting strategies along vegetation gradients (H1), and among habitat types (H2). Increasing the availability of web-anchoring structures in open grasslands led to increased web-builder density in open grassland, particularly for small and medium sized orb-web species that took advantage of increased physical structure. Disturbance from pyric herbivory indirectly promoted dynamic and malleable assemblages of spider species that coexisted in syntopy through effects on vegetation structure and its availability in time and space. Changes in habitat structure and heterogeneity as spatially and temporally shifting mosaics of habitat type increased the overall spider diversity at the landscape scale.

10aFire and grazing interactions10ahabitat structure10aKonza Prairie Biological Station10aSpatial and temporal heterogeneity10aSpider community1 aGómez, Jesús, Enrique1 aJoern, Anthony uhttp://krex.k-state.edu/dspace/handle/2097/3467203618nas a2200385 4500008004100000245009200041210006900133300001300202490000700215520250400222653002202726653001502748653001902763653003702782653002002819653001302839653002202852653001302874653002202887653002702909100001602936700002402952700001602976700002002992700002003012700001603032700001703048700001603065700001803081700001903099700001903118700001703137700001603154856006203170 2014 eng d00aResponses to fire differ between South African and North American grassland communities0 aResponses to fire differ between South African and North America a793 -8040 v253 a

Question Does fire frequency affect mesic grassland plant community structure and composition similarly in North America and South Africa? Location Konza Prairie Biological Station (KNZ), Kansas, USA, and Ukulinga Research Farm (URF), KwaZulu-Natal, South Africa. Methods Plant community structure and composition were compared among annually burned, unburned and intermediate treatments within two long-term fire frequency manipulation experiments in native grasslands in North America and South Africa using comparable methodology over a 5-yr period. Because fire may reduce soil nitrogen (N) availability and thus affect plant community structure, N additions were superimposed on the fire treatments as a means of assessing direct vs indirect mechanisms driving responses to fire. Results The total number of species was higher at URF (183) than at KNZ (57). Overall divergence in plant community response to fire frequency occurred despite similar responses to nutrient additions. At KNZ, more frequent fire resulted in dominance by a few, tall, deep-rooted rhizomatous grasses (e.g. Andropogon gerardii). On unburned sites, shorter, more shade-tolerant species such as Poa pratensis increased in abundance, although A. gerardii remained dominant. Species richness increased with decreasing fire frequency at KNZ. At URF, frequent fire resulted in short, diverse grassland weakly dominated by a range of grass species, including Themeda triandra, Tristachya leucothrix and Hyparrhenia hirta. Decreasing fire frequency reduced species richness and resulted in dominance by a few, relatively tall caespitose grasses such as Aristida junciformis. There was a complete turnover of dominant species between annually burned and unburned treatments at URF, while at KNZ A. gerardii and Sorghastrum nutans occurred across the range of treatments. N addition reduced species richness in both sites. Conclusions Different responses to fire frequency between KNZ and URF are likely linked to the dominant species and their characteristic traits, including height and method of clonal reproduction, with the rhizomatous growth form of A. gerardii dominating the North American grassland. South Africa does not have an equivalent grass species; instead, a range of tufted, non-rhizomatous species dominate across the fire frequency treatments at URF. Reductions in soil N due to frequent fire did not appear to be a common mechanism driving responses in community composition in these two grasslands.

10aCommunity ecology10aDivergence10aFire frequency10aKonza Prairie Biological Station10aMesic grassland10anitrogen10aNutrient addition10aRichness10atallgrass prairie10aUkulinga Research Farm1 aKirkman, K.1 aCollins, Scott., L.1 aSmith, M.D.1 aKnapp, Alan, K.1 aBurkepile, D.E.1 aBurns, C.E.1 aFynn, R.W.S.1 aHagenah, N.1 aKoerner, S.E.1 aMatchett, K.J.1 aThompson, D.I.1 aWilcox, K.R.1 aWragg, P.D. uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/jvs.1213002565nas a2200205 4500008004100000245011800041210006900159300001300228490000800241520171600249653001401965653001201979653003301991653003702024653001502061653001702076100001302093700001902106856023402125 2012 eng d00aVariable effects of dipteran parasitoids and management treatment on grasshopper fecundity in a tallgrass prairie0 aVariable effects of dipteran parasitoids and management treatmen a123 -1300 v1023 a

Grasshoppers host a number of parasitoids, but little is known about their impact on grasshopper life history attributes or how those impacts may vary with land use. Here, we report on a three-year survey of nine grasshopper species in a tallgrass prairie managed with fire and bison grazing treatments. We measured parasitoid prevalence and the impact of parasitoid infection on grasshopper fecundity to determine if grasshopper-parasitoid interactions varied with management treatment. Adult female grasshoppers were collected every three weeks from eight watersheds managed with different prescribed burning and grazing treatments. Grasshopper fecundity with and without parasitoids was estimated through dissections of reproductive tracts. Dipteran parasitoids from two families (Nemestrinidae and Tachinidae) were observed infecting grasshoppers. We found significant effects of grazing treatment, but not burn interval, on grasshopper-parasitoid interactions. Parasitoids were three times more abundant in watersheds with bison grazing than in ungrazed watersheds, and the relative abundance of nemestrinid and tachinid flies varied with grazing treatment. Parasitoid prevalence varied among grasshopper species from <0.01% infected (Mermiria bivittata) to 17% infected (Hypochlora alba). Parasitoid infection reduced individual grasshopper fecundity, with stronger effects on current reproduction than on past reproduction. Furthermore, current fecundity in parasitized grasshoppers was lower in grazed watersheds compared to ungrazed watersheds. Nemestrinid parasitoids generally had stronger impacts on grasshopper fecundity than tachinid parasitoids, the effects of which were more variable.

10agrassland10aGrazing10ahost-parasitoid interactions10aKonza Prairie Biological Station10aOrthoptera10areproduction1 aLaws, A.1 aJoern, Anthony uhttps://www.cambridge.org/core/journals/bulletin-of-entomological-research/article/variable-effects-of-dipteran-parasitoids-and-management-treatment-on-grasshopper-fecundity-in-a-tallgrass-prairie/EB1AD93DB7D975E1009489797D88DF2E02323nas a2200193 4500008004100000245007900041210006900120300001300189490000700202520169800209653003701907653001701944653001501961653001501976653001701991100001302008700001902021856008902040 2011 eng d00aGrasshopper fecundity responses to grazing and fire in a tallgrass prairie0 aGrasshopper fecundity responses to grazing and fire in a tallgra a979 -9880 v403 a

Grasshopper abundance and diversity vary with management practices such as fire and grazing. Understanding how grasshopper life history traits such as fecundity respond to management practices is key to predicting grasshopper population dynamics in heterogeneous environments. Landscape-level experimental fire and bison grazing treatments at the Konza Prairie Biological Station (Manhattan, KS) provide an opportunity to examine how management affects grasshopper fecundity. Here we report on grasshopper fecundity for nine common species at Konza Prairie. From 2007 to 2009, adult female grasshoppers were collected every 3 wk from eight watersheds that varied in fire and grazing treatments. Fecundity was measured by examining female reproductive tracts, which contain a record of past and current reproductive activity. Body size was a poor predictor of fecundity for all species. Despite large differences in vegetation structure and composition with management regime (grazing and fire interval), we observed little effect of management on grasshopper fecundity. Habitat characteristics (grasshopper density, vegetation biomass, and vegetation quality; measured in 2008 and 2009) were better predictors of past fecundity than current fecundity, with species-specific responses. Fecundity increased throughout the summer, indicating that grasshoppers were able to acquire sufficient nutritional resources for egg production in the early fall when vegetation quality is generally low. Because fecundity did not vary across management treatments, population stage structure may be more important for determining population level reproduction than management regime at Konza Prairie.

10aKonza Prairie Biological Station10alife-history10amanagement10aOrthoptera10areproduction1 aLaws, A.1 aJoern, Anthony uhttps://academic.oup.com/ee/article-abstract/40/5/979/412531?redirectedFrom=fulltext01909nas a2200217 4500008004100000245015500041210006900196300001300265490000700278520109200285653003701377653002701414653001701441653002401458653001401482100001801496700001801514700001601532700001701548856012601565 2005 eng d00aCarrion beetles (Coleoptera: Silphidae) of the Konza Prairie Biological Stationbeetles (Coleoptera: Silphidae) of the Konza Prairie Biological Station0 aCarrion beetles Coleoptera Silphidae of the Konza Prairie Biolog a124 -1230 v783 aPitfall traps were used to determine diversity, seasonality, and numbers of burying beetles on the Konza Prairie Biological Station (KPBS) during the summers of 1997 and 1998. Traps were baited with either beef liver (1997) or whole mouse carcasses (1997 and 1998); significantly more carrion beetles were found in traps baited with carcasses. A total of 1003 carrion beetles, representing 8 species, were trapped over the course of 1556 trap nights. One of these species, Necrophila americana Linneaus, had not previously been recorded in Riley County. One additional species was found at sites where pitfall trap bait was discarded, bringing the total number of KPBS silphid species to 9. Bait age was an important determinant in attracting silphids to pitfall traps, as numbers of beetles in the trap continued to increase with bait age up to 6 days. Grassland topography (upland vs. lowland trap sites) significantly affected the numbers of carrion beetles trapped. Grassland burn history did not affect number of carrion beetles trapped, but did seem to influence species diversity.10aKonza Prairie Biological Station10aNicrophorus marginatus10apitfall trap10aseasonal occurrence10aSilphidae1 aRintoul, D.A.1 aKrueger, L.M.1 aWoodard, C.1 aThrone, J.E. uhttp://lter.konza.ksu.edu/content/carrion-beetles-coleoptera-silphidae-konza-prairie-biological-stationbeetles-coleoptera02937nas a2200229 4500008004100000245009500041210006900136300001200205490000700217520214000224653003102364653001602395653001302411653003702424653001902461653001902480653002502499653002202524100002002546700001702566856012402583 2002 eng d00aMacroinvertebrate production and trophic structure in a tallgrass prairie headwater stream0 aMacroinvertebrate production and trophic structure in a tallgras a97 -1130 v213 aResearch on North American prairie stream communities has lagged behind other regions. We examined the ecosystem significance of the macroinvertebrate community of riffle/run habitats in Kings Creek, a 2nd-order tallgrass prairie stream at Konza Prairie Biological Station (Kansas, USA), by estimating secondary production, benthic organic matter standing stocks, and resource consumption and egestion by functional groups. Annual mean standing stock macroinvertebrate biomass was 2.3 g ash-free dry mass (AFDM)/m2, annual production was 19.7 g AFDM m-2 y-1, and the annual community production/biomass (P/B) ratio was 8.6. Macroinvertebrate production was higher than published estimates for forested streams of similar size, but much lower than that of a Sonoran desert stream. Distribution of production among functional groups was 30% for collector-gatherers, 9% for collector-filterers, 20% for scrapers, 23% for shredders, and 18% for predators, resembling estimates from some forested streams with the exception of higher scraper production. Although detritivorous groups were productive in this prairie stream, they appeared food limited. Consumption estimates indicated shredders and collector-gatherers annually ingested ∼80% and ∼240% of coarse particulate organic matter (CPOM) and fine particulate organic matter (FPOM) standing stocks, respectively. Thus, re-ingestion and/or diet shifts may be common, particularly among collector-gatherers, and the FPOM pool must turn over rapidly. Invertebrate predators also consumed a sizeable portion (∼52%) of prey, whereas scrapers (∼21%) and filterers (<1%) consumed relatively small portions of their respective resources, suggesting top-down influences on these groups. This study indicates that, during a period of relatively stable flow in this prairie stream, macroinvertebrate production and functional structure were roughly intermediate between North American forested and desert systems. Our results underscore the value of secondary production estimates for examining invertebrate communities in an ecosystem context10aAquatic macroinvertebrates10aEnergy flow10aFood web10aKonza Prairie Biological Station10aorganic matter10aPrairie stream10asecondary production10aTrophic structure1 aStagliano, D.M.1 aWhiles, M.R. uhttp://lter.konza.ksu.edu/content/macroinvertebrate-production-and-trophic-structure-tallgrass-prairie-headwater-stream