| effects of nitrogen and sulfur on digestion and nutritive quality of warm-season grass hays for cattle and sheep. | the influence of n and s on the usage of warm-season grasses was examined in two metabolism trials with cattle and sheep. effects of n fertilization (75 kg n from urea/ha) on digestibility, intake, and ruminal mineral solubilization of switchgrass (panicum virgatum l.; swg) and big bluestem (andropogon gerardii vitm.; bb) hays were determined in a 4 x 4 latin square experiment with mature steers. effects of n and s applied as urea and sodium sulfate in spray form to swg hay were estimated in a 2 ... | 1991 | 1849882 |
| characterization of a bacterium of the genus azospirillum from cellulolytic nitrogen-fixing mixed cultures. | a bacterium with the taxonomic characteristics of the genus azospirillum was isolated from celluloytic n2-fixing mixed cultures. its characteristics fit the descriptions of both azopirillum lipoferum (beijerinck) comb. nov. and azospirillum brasilense sp. nov. it may be a variant strain of a. lipoferum. in mixed cultures with cellulolytic organisms, the bacterium grew and fixed n2 with cellelose as a sole source of energy and carbon. the mixed cultures used cellulose from leaves of wheat (tritic ... | 1980 | 6773649 |
| ruminal degradation of switchgrass, big bluestem, and smooth bromegrass leaf proteins. | two in situ protein disappearance experiments were conducted to determine disappearance rates of leaf protein fractions and characterize individual leaf protein fractions that escaped ruminal degradation. fresh leaf blades of two warm-season grasses, switchgrass (panicum virgatum l.) and big bluestem (andropogon gerardii vitman), and one cool-season grass, smooth bromegrass (bromus inermis leyss.), were included in exp. 1. only warm-season grasses were used in exp. 2. leaves were harvested from ... | 1995 | 7601796 |
| supplementation of growing cattle grazing warm-season grass with proteins of various ruminal degradabilities. | this study was conducted to determine in situ ruminal protein degradation and animal responses to ruminally degraded and escape protein supplementation of warm-season grass. cattle grazed a mixed stand of primarily big bluestem (andropogon gerardii vitman) and switchgrass (panicum virgatum l.) with some indiangrass (sorghastrum nutans [l.] nash) from the 1st wk of june to the 3rd wk of august. in 1987, 72 yearling steers (286 kg) were allotted randomly to three treatments: energy control (cornst ... | 1993 | 8074742 |
| elucidation of factors associated with the maturity-related decline in degradability of big bluestem cell wall. | big bluestem (andropogon gerardii) forage samples were collected from three ungrazed, annually burned pastures at 38, 58, and 97 d after burning. cell wall material received five treatments: chlorite delignification, chlorite delignification plus alkali extraction, naoh, naoch3 in methanol, or nabh4. untreated and treated cell walls were analyzed for carbohydrate composition (glucose, xylose, arabinose, galactose, and uronic acids), acetyl bromide lignin, acid detergent lignin, alkali-labile phe ... | 1996 | 8707723 |
| evaluation of microbial inoculation and vegetation to enhance the dissipation of atrazine and metolachlor in soil. | four greenhouse studies were conducted to evaluate the effects of native prairie grasses and two pesticide-degrading bacteria to remediate atrazine and metolachlor in soils from agricultural dealerships (alpha site soil, northwest iowa, usa; bravo site soil, central iowa, usa). the alpha soil contained a low population of atrazine-degrading microorganisms relative to the bravo soil. each soil freshly treated with atrazine or metolachlor was aged for a short or long period of time, respectively. ... | 2005 | 16268144 |
| fermentability of eastern gamagrass, big bluestem and sand bluestem grown across a wide variety of environments. | plant biomass has attracted interest as a feedstock for biofuels production, but much of this work has been focused on relatively few plant species. in this study, three relatively-unstudied species of warm-season perennial grasses, grown at multiple locations in the eastern and central us and harvested over a three year period, were examined for fermentability via in vitro ruminal gas production and dry matter digestibility assays, and near-infrared reflectance calibrations were developed for t ... | 2007 | 16962323 |
| management of warm-season grass mixtures for biomass production in south dakota usa. | switchgrass (panicum virgatum l.), big bluestem (andropogon gerardii vitman), and indiangrass (sorghastrum nutans (l.) nash) are native warm-season grasses commonly used for pasture, hay, and conservation. more recently switchgrass has also been identified as a potential biomass energy crop, but management of mixtures of these species for biomass is not well documented. therefore, the objectives of our study were to: (1) determine the effects of harvest timing and n rate on yield and biomass cha ... | 2008 | 17349789 |
| nonstomatal versus stomatal uptake of atmospheric mercury. | atmospheric constituents may be deposited to and incorporated into plant leaves, with gases entering via stomata, and gas and particles being sorbed at the surface and in some cases traversing the cuticle, possibly reaching the epidermis. plants are known to be a sink for atmospheric mercury (hg), and the current paradigm is that uptake of gaseous elemental hg occurs by way of the stomata. four plant species, rudbeckia hirta, sorghastrum nutans, andropogon gerardii, and populus tremuloides, were ... | 2009 | 19350905 |
| isolation and morphological and metabolic characterization of common endophytes in annually burned tallgrass prairie. | dark septate endophytes (dse) are common and abundant root-colonizing fungi in the native tallgrass prairie. to characterize dse fungi were isolated from roots of mixed tallgrass prairie plant communities. isolates were grouped according to morphology, and the grouping was refined by its-rflp and/or sequencing of the its region. sporulating species of periconia, fusarium, microdochium and aspergillus were isolated along with many sterile fungi. leek resynthesis was used to quickly screen for dse ... | 2010 | 20648749 |
| herbivore and fungal pathogen exclusion affects the seed production of four common grassland species. | insect herbivores and fungal pathogens can independently affect plant fitness, and may have interactive effects. however, few studies have experimentally quantified the joint effects of insects and fungal pathogens on seed production in non-agricultural populations. we examined the factorial effects of insect herbivore exclusion (via insecticide) and fungal pathogen exclusion (via fungicide) on the population-level seed production of four common graminoid species (andropogon gerardii, schizachyr ... | 2010 | 20711408 |
| climate controls on grass culm production over a quarter century in a tallgrass prairie. | the flowering of grasses is a process critical to plant population dynamics and genetics, herbivore performance, and human health. to better understand the climate factors governing grass flowering, we analyzed the patterns of culm production over 25 years for three perennial tallgrass prairie species at konza prairie in kansas, usa. the three species (andropogon gerardii, sorghastrum nutans, and schizachyrium scoparium) all utilize the c4 photosynthetic pathway and were measured annually at the ... | 2010 | 20715635 |
| septate endophyte colonization and host responses of grasses and forbs native to a tallgrass prairie. | native tallgrass prairies support distinct dark septate endophyte (dse) communities exemplified by periconia macrospinosa and microdochium sp. that were recently identified as common root symbionts in this system. since these dse fungi were repeatedly isolated from grasses and forbs, we aimed to test their abilities to colonize different hosts. one microdochium and three periconia strains were screened for colonization and growth responses using five native grasses and six forbs in an in vitro s ... | 2011 | 21538095 |
| genomic and resistance gene homolog diversity of the dominant tallgrass prairie species across the u.s. great plains precipitation gradient. | environmental variables such as moisture availability are often important in determining species prevalence and intraspecific diversity. the population genetic structure of dominant plant species in response to a cline of these variables has rarely been addressed. we evaluated the spatial genetic structure and diversity of andropogon gerardii populations across the u.s. great plains precipitation gradient, ranging from approximately 48 cm/year to 105 cm/year. | 2011 | 21532756 |
| colletotrichum caudatum s.l. is a species complex. | colletotrichum caudatum sensu lato is a widespread fungal pathogen of warm-season grasses. the fungus is easily differentiated from other colletotrichum species through the presence of a unique filiform appendage at the apex of the conidium. multi-locus phylogenetic analysis of four dna sequence markers from 21 isolates of c. caudatum s.l. from six grass hosts recovered the morphospecies as a well-supported monophyletic group. although closely related to other colletotrichum species pathogenic t ... | 2014 | 25083403 |
| an assessment of diurnal water uptake in a mesic prairie: evidence for hydraulic lift? | hydraulic lift, the passive movement of water through plant roots from wet to dry soil, is an important ecohydrological process in a wide range of water-limited ecosystems. this phenomenon may also alter plant functioning, growth, and survival in mesic grasslands, where soil moisture is spatially and temporally variable. here, we monitored diurnal changes in the isotopic signature of soil and plant xylem water to assess (1) whether hydraulic lift occurs in woody and herbaceous tallgrass prairie ... | 2017 | 28154965 |
| phenotypic distribution models corroborate species distribution models: a shift in the role and prevalence of a dominant prairie grass in response to climate change. | phenotypic distribution within species can vary widely across environmental gradients but forecasts of species' responses to environmental change often assume species respond homogenously across their ranges. we compared predictions from species and phenotype distribution models under future climate scenarios for andropogon gerardii, a widely distributed, dominant grass found throughout the central united states. phenotype data on aboveground biomass, height, leaf width, and chlorophyll content ... | 2017 | 28211151 |
| native plants fare better against an introduced competitor with native microbes and lower nitrogen availability. | while the soil environment is generally acknowledged as playing a role in plant competition, the relative importance of soil resources and soil microbes in determining outcomes of competition between native and exotic plants has rarely been tested. resilience of plant communities to invasion by exotic species may depend on the extent to which native and exotic plant performance are mediated by abiotic and biotic components of the soil. we used a greenhouse experiment to compare performance of tw ... | 2017 | 28122737 |
| plant community richness mediates inhibitory interactions and resource competition between streptomyces and fusarium populations in the rhizosphere. | plant community characteristics impact rhizosphere streptomyces nutrient competition and antagonistic capacities. however, the effects of streptomyces on, and their responses to, coexisting microorganisms as a function of plant host or plant species richness have received little attention. in this work, we characterized antagonistic activities and nutrient use among streptomyces and fusarium from the rhizosphere of andropogon gerardii (ag) and lespedeza capitata (lc) plants growing in communitie ... | 2017 | 28058470 |
| timing effects of heat-stress on plant ecophysiological characteristics and growth. | heat-waves with higher intensity and frequency and longer durations are expected in the future due to global warming, which could have dramatic impacts in agriculture, economy and ecology. this field study examined how plant responded to heat-stress (hs) treatment at different timing in naturally occurring vegetation. hs treatment (5 days at 40.5°c) were applied to 12 1 m(2) plots in restored prairie vegetation dominated by a warm-season c4 grass, andropogon gerardii, and a warm-season c3 forb, ... | 2016 | 27853463 |
| photosynthetic responses of a dominant c4 grass to an experimental heat wave are mediated by soil moisture. | extreme heat waves and drought are predicted to increase in frequency and magnitude with climate change. these extreme events often co-occur, making it difficult to separate their direct and indirect effects on important ecophysiological and carbon cycling processes such as photosynthesis. here, we assessed the independent and interactive effects of experimental heat waves and drought on photosynthesis in andropogon gerardii, a dominant c4 grass in a native mesic grassland. we experimentally imp ... | 2017 | 27757543 |
| genotypic diversity effects on biomass production in native perennial bioenergy cropping systems. | the perennial grass species that are being developed as biomass feedstock crops harbor extensive genotypic diversity, but the effects of this diversity on biomass production are not well understood. we investigated the effects of genotypic diversity in switchgrass (panicum virgatum) and big bluestem (andropogon gerardii) on perennial biomass cropping systems in two experiments conducted over 2008-2014 at a 5.4-ha fertile field site in northeastern illinois, usa. we varied levels of switchgrass a ... | 2016 | 27668013 |
| mycorrhizas influence functional traits of two tallgrass prairie species. | over the past decade, functional traits that influence plant performance and thus, population, community, and ecosystem biology have garnered increasing attention. generally lacking, however, has been consideration of how ubiquitous arbuscular mycorrhizas influence plant allometric and stoichiometric functional traits. we assessed how plant dependence on and responsiveness to mycorrhizas influence plant functional traits of a warm-season, c4 grass, andropogon gerardii vitman, and the contrasting ... | 2016 | 27516857 |
| single nucleotide polymorphism discovery via genotyping by sequencing to assess population genetic structure and recurrent polyploidization in andropogon gerardii. | autopolyploidy, genome duplication within a single lineage, can result in multiple cytotypes within a species. geographic distributions of cytotypes may reflect the evolutionary history of autopolyploid formation and subsequent population dynamics including stochastic (drift) and deterministic (differential selection among cytotypes) processes. here, we used a population genomic approach to investigate whether autopolyploidy occurred once or multiple times in andropogon gerardii, a widespread, n ... | 2016 | 27466055 |
| plant-fungus competition for nitrogen erases mycorrhizal growth benefits of andropogon gerardii under limited nitrogen supply. | considered to play an important role in plant mineral nutrition, arbuscular mycorrhizal (am) symbiosis is a common relationship between the roots of a great majority of plant species and glomeromycotan fungi. its effects on the plant host are highly context dependent, with the greatest benefits often observed in phosphorus (p)-limited environments. mycorrhizal contribution to plant nitrogen (n) nutrition is probably less important under most conditions. moreover, inasmuch as both plant and fungi ... | 2016 | 27386079 |
| common mycorrhizal networks amplify competition by preferential mineral nutrient allocation to large host plants. | arbuscular mycorrhizal (am) fungi interconnect plants in common mycorrhizal networks (cmns) which can amplify competition among neighbors. amplified competition might result from the fungi supplying mineral nutrients preferentially to hosts that abundantly provide fixed carbon, as suggested by research with organ-cultured roots. we examined whether cmns supplied (15) n preferentially to large, nonshaded, whole plants. we conducted an intraspecific target-neighbor pot experiment with andropogon g ... | 2016 | 27265515 |
| gene expression patterns of two dominant tallgrass prairie species differ in response to warming and altered precipitation. | to better understand the mechanisms underlying plant species responses to climate change, we compared transcriptional profiles of the co-dominant c4 grasses, andropogon gerardii vitman and sorghastrum nutans (l.) nash, in response to increased temperatures and more variable precipitation regimes in a long-term field experiment in native tallgrass prairie. we used microarray probing of a closely related model species (zea mays) to assess correlations in leaf temperature (tleaf) and leaf water pot ... | 2016 | 27174156 |
| dual, differential isotope labeling shows the preferential movement of labile plant constituents into mineral-bonded soil organic matter. | the formation and stabilization of soil organic matter (som) are major concerns in the context of global change for carbon sequestration and soil health. it is presently believed that lignin is not selectively preserved in soil and that chemically labile compounds bonding to minerals comprise a large fraction of the som. labile plant inputs have been suggested to be the main precursor of the mineral-bonded som. litter decomposition and som formation are expected to have temperature sensitivity v ... | 2016 | 27142168 |
| inferential considerations for low-count rna-seq transcripts: a case study on the dominant prairie grass andropogon gerardii. | differential expression (de) analysis of rna-seq data still poses inferential challenges, such as handling of transcripts characterized by low expression levels. in this study, we use a plasmode-based approach to assess the relative performance of alternative inferential strategies on rna-seq transcripts, with special emphasis on transcripts characterized by a small number of read counts, so-called low-count transcripts, as motivated by an ecological application in prairie grasses. big bluestem ... | 2016 | 26919855 |
| the effect of timing of growing season drought on flowering of a dominant c4 grass. | timing of precipitation is equally important as amount for determining ecosystem function, especially aboveground net primary productivity (anpp), in a number of ecosystems. in tallgrass prairie of the central plains of north america, grass flowering stalks of dominant c4 grasses, such as andropogon gerardii, can account for more than 70 % of anpp, or almost none of it, as the number of flowering stalks produced is highly variable. although growing season precipitation amount is important for dr ... | 2016 | 26886131 |
| the role of ecotypic variation and the environment on biomass and nitrogen in a dominant prairie grass. | knowledge of the relative strength of evolution and the environment on a phenotype is required to predict species responses to environmental change and decide where to source plant material for ecological restoration. this information is critically needed for dominant species that largely determine the productivity of the central u.s. grassland. we established a reciprocal common garden experiment across a longitudinal gradient to test whether ecotypic variation interacts with the environment to ... | 2015 | 26594700 |
| intraspecific variation of a dominant grass and local adaptation in reciprocal garden communities along a us great plains' precipitation gradient: implications for grassland restoration with climate change. | identifying suitable genetic stock for restoration often employs a 'best guess' approach. without adaptive variation studies, restoration may be misguided. we test the extent to which climate in central us grasslands exerts selection pressure on a foundation grass big bluestem (andropogon gerardii), widely used in restorations, and resulting in local adaptation. we seeded three regional ecotypes of a. gerardii in reciprocal transplant garden communities across 1150 km precipitation gradient. we ... | 2015 | 26240607 |
| plant community richness and microbial interactions structure bacterial communities in soil. | plant species, plant community diversity and microbial interactions can significantly impact soil microbial communities, yet there are few data on the interactive effects of plant species and plant community diversity on soil bacterial communities. we hypothesized that plant species and plant community diversity affect soil bacterial communities by setting the context in which bacterial interactions occur. specifically, we examined soil bacterial community composition and diversity in relation t ... | 2015 | 26236898 |
| glyphosate and dicamba herbicide tank mixture effects on native plant and non-genetically engineered soybean seedlings. | crops engineered to contain genes for tolerance to multiple herbicides may be treated with several herbicides to manage weeds resistant to each herbicide. thus, nearby non-target plants may be subjected to increased exposure to several herbicides used in combination. of particular concern are native plants, as well as adjacent crops which have not been genetically engineered for tolerance to herbicides. we evaluated responses of seven species of native plants grown in a greenhouse and treated le ... | 2015 | 25821135 |
| environmental correlates of cytotype distribution in andropogon gerardii (poaceae). | • | 2015 | 25587152 |
| annual burning of a tallgrass prairie inhibits c and n cycling in soil, increasing recalcitrant pyrogenic organic matter storage while reducing n availability. | grassland ecosystems store an estimated 30% of the world's total soil c and are frequently disturbed by wildfires or fire management. aboveground litter decomposition is one of the main processes that form soil organic matter (som). however, during a fire biomass is removed or partially combusted and litter inputs to the soil are substituted with inputs of pyrogenic organic matter (py-om). py-om accounts for a more recalcitrant plant input to som than fresh litter, and the historical frequency o ... | 2015 | 25487951 |
| mycorrhizal phenotypes and the law of the minimum. | mycorrhizal phenotypes arise from interactions among plant and fungal genotypes and the environment. differences in the stoichiometry and uptake capacity of fungi and plants make arbuscular mycorrhizal (am) fungi inherently more nitrogen (n) limited and less phosphorus (p) limited than their host plants. mutualistic phenotypes are most likely in p-limited systems and commensal or parasitic phenotypes in n-limited systems. carbon (c) limitation is expected to cause phenotypes to shift from mutual ... | 2015 | 25417818 |
| ecotypes of an ecologically dominant prairie grass (andropogon gerardii) exhibit genetic divergence across the u.s. midwest grasslands' environmental gradient. | big bluestem (andropogon gerardii) is an ecologically dominant grass with wide distribution across the environmental gradient of u.s. midwest grasslands. this system offers an ideal natural laboratory to study population divergence and adaptation in spatially varying climates. objectives were to: (i) characterize neutral genetic diversity and structure within and among three regional ecotypes derived from 11 prairies across the u.s. midwest environmental gradient, (ii) distinguish between the re ... | 2014 | 25370460 |
| dissolution, sorption, and phytoremediation of imx-101 explosive formulation constituents: 2,4-dinitroanisole (dnan), 3-nitro-1,2,4-triazol-5-one (nto), and nitroguanidine. | the insensitive munition, imx-101 approved for use in the usa, contains 2,4-dinitroanisole (dnan), 3-nitro-1,2,4-triazol-5-one (nto), and nitroguanidine (nq) and is designed to be less sensitive to shock and sympathetic detonation. given the estimated future use of imx-101, an understanding of imx-101 constituent attenuation mechanisms on testing and training ranges is needed. studies were conducted to determine (1) the rates of imx-101 fragment dissolution during simulated rainfall, (2) dnan an ... | 2014 | 25212590 |
| impact of a short-term heat event on c and n relations in shoots vs. roots of the stress-tolerant c4 grass, andropogon gerardii. | global warming will increase heat waves, but effects of abrupt heat stress on shoot-root interactions have rarely been studied in heat-tolerant species, and abrupt heat-stress effects on root n uptake and shoot c flux to roots and soil remains uncertain. we investigated effects of a high-temperature event on shoot vs. root growth and function, including transfer of shoot c to roots and soil and uptake and translocation of soil n by roots in the warm-season drought-tolerant c4 prairie grass, andr ... | 2014 | 24974323 |
| loss of a large grazer impacts savanna grassland plant communities similarly in north america and south africa. | large herbivore grazing is a widespread disturbance in mesic savanna grasslands which increases herbaceous plant community richness and diversity. however, humans are modifying the impacts of grazing on these ecosystems by removing grazers. a more general understanding of how grazer loss will impact these ecosystems is hampered by differences in the diversity of large herbivore assemblages among savanna grasslands, which can affect the way that grazing influences plant communities. to avoid this ... | 2014 | 24554031 |
| design and operation of a continuous 13c and 15n labeling chamber for uniform or differential, metabolic and structural, plant isotope labeling. | tracing rare stable isotopes from plant material through the ecosystem provides the most sensitive information about ecosystem processes; from co2 fluxes and soil organic matter formation to small-scale stable-isotope biomarker probing. coupling multiple stable isotopes such as (13)c with (15)n, (18)o or (2)h has the potential to reveal even more information about complex stoichiometric relationships during biogeochemical transformations. isotope labeled plant material has been used in various s ... | 2014 | 24457314 |
| nutritive value response of native warm-season forage grasses to harvest intervals and durations in mixed stands. | interest in management of native warm-season grasses for multiple uses is growing in southeastern usa. forage quality response of early-succession mixed stands of big bluestem (bb, andropogon gerardii), indiangrass (ig, sorghastrum nutans), and little bluestem (sg, schizachyrium scoparium) to harvest intervals (30-, 40-, 60-, 90 or 120-d) and durations (one or two years) were assessed in crop-field buffers. over three years, phased harvestings were initiated in may, on sets of randomized plots, ... | 2014 | 27135504 |
| diffuse symbioses: roles of plant-plant, plant-microbe and microbe-microbe interactions in structuring the soil microbiome. | a conceptual model emphasizing direct host-microbe interactions has dominated work on host-associated microbiomes. to understand plant-microbiome associations, however, broader influences on microbiome composition and functioning must be incorporated, such as those arising from plant-plant and microbe-microbe interactions. we sampled soil microbiomes associated with target plant species (andropogon gerardii, schizachyrium scoparium, lespedeza capitata, lupinus perennis) grown in communities vary ... | 2014 | 24148029 |
| environmental and genetic variation in leaf anatomy among populations of andropogon gerardii (poaceae) along a precipitation gradient. | | 2013 | 24061213 |
| rhizosphere bacterial communities associated with long-lived perennial prairie plants vary in diversity, composition, and structure. | the goal of this research was to investigate the variation in rhizosphere microbial community composition, diversity, and structure among individual andropogon gerardii vitman (big bluestem) and lespedeza capitata michx. (bush clover). bacterial communities from the rhizosphere of 10 plants of each species (n = 20 plants total) were explored using a culture-independent pipeline. microbial communities associated with both host plants had high bacterial diversity within individual plant rhizospher ... | 2013 | 23826959 |
| resource availability and imbalance affect plant-mycorrhizal interactions: a field test of three hypotheses. | ecological stoichiometry can explain major trends in how interactions among species change across fertility gradients, but important questions remain. for example, stoichiometry predicts that fertilization should cause plants to reduce carbon allocation to arbuscular mycorrhizal fungi and, consequently, reduce fungal abundance, but responses in the field are highly variable. in a field experiment, we tested three hypotheses that could drive this variation: (1) fungi are nitrogen limited in very ... | 2013 | 23600241 |
| native michigan plants stimulate soil microbial species changes and pah remediation at a legacy steel mill. | a 1.3-acre phytoremediation site was constructed to mitigate polyaromatic hydrocarbon (pah) contamination from a former steel mill in michigan. soil was amended with 10% (v/v) compost and 5% (v/v) poultry litter. the site was divided into twelve 11.89 m x 27.13 m plots, planted with approximately 35,000 native michigan perennials, and soils sampled for three seasons. soil microbial density generally increased in subplots of eupatorium perfoliatum (boneset), aster novae-angliae (new england aster ... | 2013 | 23487982 |
| patterns of diversity and adaptation in glomeromycota from three prairie grasslands. | arbuscular mycorrhizal (am) fungi are widespread root symbionts that often improve the fitness of their plant hosts. we tested whether local adaptation in mycorrhizal symbioses would shape the community structure of these root symbionts in a way that maximizes their symbiotic functioning. we grew a native prairie grass (andropogon gerardii) with all possible combinations of soils and am fungal inocula from three different prairies that varied in soil characteristics and disturbance history (two ... | 2013 | 23458035 |
| common mycorrhizal networks amplify size inequality in andropogon gerardii monocultures. | arbuscular mycorrhizal fungi can interconnect plant root systems through hyphal common mycorrhizal networks, which may influence the distribution of limiting mineral nutrients among interconnected individuals, potentially affecting competition and consequent size inequality. using a microcosm model system, we investigated whether the members of andropogon gerardii monocultures compete via common mycorrhizal networks. we grew a. gerardii seedlings with isolated root systems in individual, adjacen ... | 2013 | 23356215 |
| effects of plant host species and plant community richness on streptomycete community structure. | we investigated soil streptomycete communities associated with four host plant species (two warm season c4 grasses: andropogon gerardii, schizachyrium scoparium and two legumes: lespedeza capitata, lupinus perennis), grown in plant communities varying in species richness. we used actinobacteria-selective pcr coupled with pyrosequencing to characterize streptomycete community composition and structure. the greatest pairwise distances between communities were observed in contrasts between monocult ... | 2013 | 23013423 |
| plant tissue analysis for explosive compounds in phytoremediation and phytoforensics. | plant tissue analysis methods were evaluated for six explosive compounds to assess uptake and phytoforensic methods development to quantify explosives in plant to obtain the plant data for the evaluation of explosive contamination in soil and groundwater. four different solvent mixtures containing acetonitrile or methanol were tested at variable extraction ratios to compare the extraction efficiency for six explosive compounds: 2,4,6-trinitrotoluene (tnt), pentaerythritoltetranitrate (petn), hex ... | 2012 | 22934993 |
| genetic diversity of a dominant c4 grass is altered with increased precipitation variability. | climate change has the potential to alter the genetic diversity of plant populations with consequences for community dynamics and ecosystem processes. recent research focused on changes in climatic means has found evidence of decreased precipitation amounts reducing genetic diversity. however, increased variability in climatic regimes is also predicted with climate change, but the effects of this aspect of climate change on genetic diversity have yet to be investigated. after 10 years of experim ... | 2013 | 22907523 |
| plant species differ in their ability to reduce allocation to non-beneficial arbuscular mycorrhizal fungi. | theory suggests that cheaters threaten the persistence of mutualisms, but that sanctions to prevent cheating can stabilize mutualisms. in the arbuscular mycorrhizal symbiosis, reports of parasitism suggest that reductions in plant carbon allocation are not universally effective. i asked whether plant species differences in mycorrhizal responsiveness would affect both their susceptibility to parasitism and their reduction in allocation to non-beneficial arbuscular mycorrhizal fungi (amf) in high- ... | 2012 | 22690621 |
| hydrothermal conversion of big bluestem for bio-oil production: the effect of ecotype and planting location. | three ecotypes (cks, eks, il) and one cultivar (kaw) of big bluestem (andropogon gerardii) that were planted in three locations (hays, ks; manhattan, ks; and carbondale, il) were converted to bio-oil via hydrothermal conversion. significant differences were found in the yield and elemental composition of bio-oils produced from big bluestem of different ecotypes and/or planting locations. generally, the il ecotype and the carbondale, il and manhattan, ks planting locations gave higher bio-oil yie ... | 2012 | 22525265 |
| resource limitation and the role of a hemiparasite on a restored prairie. | hemiparasitic plants tend to thrive in and significantly affect plant communities in low-nutrient, high-light environments. hemiparasites are assumed to be weak competitors for light but strong parasites, leading to the prediction that effects on hosts and communities should be a function of resource supply. we investigated the effects of light and mineral nutrients on hemiparasite-host relations in two experiments. removal of the hemiparasite, addition of fertilizer, and full sun significantly ... | 2012 | 22215230 |
| invasion of an intact plant community: the role of population versus community level diversity. | to improve the understanding of how native plant diversity influences invasion, we examined how population and community diversity may directly and indirectly be related to invasion in a natural field setting. due to the large impact of the dominant c(4) grass species (andropogon gerardii) on invasion resistance of tallgrass prairie, we hypothesized that genetic diversity and associated traits within a population of this species would be more strongly related to invasion than diversity or traits ... | 2012 | 22015570 |
| invasive warm-season grasses reduce mycorrhizal root colonization and biomass production of native prairie grasses. | soil organisms play important roles in regulating ecosystem-level processes and the association of arbuscular mycorrhizal (am) fungi with a plant species can be a central force shaping plant species' ecology. understanding how mycorrhizal associations are affected by plant invasions may be a critical aspect of the conservation and restoration of native ecosystems. we examined the competitive ability of old world bluestem, a non-native grass (caucasian bluestem [bothriochloa bladhii]), and the in ... | 2012 | 21845465 |
| bud production and dynamics of flowering and vegetative tillers in andropogon gerardii (poaceae): the role of developmental constraints. | perennial grasses maintain aboveground tiller populations through vegetative reproduction via belowground buds and sexual reproduction via seed. the maintenance of a bud bank has important demographic consequences for perennial grasses. a tradeoff between these reproductive modes would be expected for a plant with limited resource availability. however, the ontogeny of the tiller could affect its ability to allocate between these two modes of reproduction. | 2011 | 21788531 |
| isolation and characterization of microsatellite markers for bothriochloa ischaemum (poaceae). | microsatellite primers were developed for bothriochloa ischaemum to investigate the structure of invasive populations within texas and determine the origin of introduction from within the native range. | 2011 | 21700803 |
| linking plant growth responses across topographic gradients in tallgrass prairie. | aboveground biomass in grasslands varies according to landscape gradients in resource availability and seasonal patterns of growth. using a transect spanning a topographic gradient in annually burned ungrazed tallgrass prairie, we measured changes in the height of four abundant c(4) grass species, lai, biomass, and cumulative carbon flux using two closely located eddy flux towers. we hypothesized that seasonal patterns of plant growth would be similar across the gradient, but the magnitude of gr ... | 2011 | 21380849 |
| analysis of ribosomal rna indicates seasonal fungal community dynamics in andropogon gerardii roots. | use of the reverse-transcribed small subunit of the ribosomal rna (rrna) was tested for exploring seasonal dynamics of fungal communities associated with the roots of the dominant tallgrass prairie grass, andropogon gerardii. ribosomal rna was extracted, reverse-transcribed, and pcr-amplified in four sampling events in may, july, september, and november. analyses of cloned pcr amplicons indicated that the a. gerardii rhizospheres host phylogenetically diverse fungal communities and that these co ... | 2011 | 21207073 |
| isolation and characterization of pyrene metabolizing microbial consortia from the plant rhizoplane. | most research on the ecology of pah degrading bacteria in the rhizosphere has focused on individual strains that grow on specific pahs. thus, there are fundamental questions as to importance of microbial consortia for pah degradation in the plant rhizosphere. the study reported here characterized cultivable pyrene degrading rhizoplane microbial communities from two different plant species using a root printing technique on agar plates. colonies were revealed by formation of clearing zones on med ... | 2010 | 21166284 |
| resource limitation is a driver of local adaptation in mycorrhizal symbioses. | symbioses may be important mechanisms of plant adaptation to their environment. we conducted a reciprocal inoculation experiment to test the hypothesis that soil fertility is a key driver of local adaptation in arbuscular mycorrhizal (am) symbioses. ecotypes of andropogon gerardii from phosphorus-limited and nitrogen-limited grasslands were grown with all possible "home and away" combinations of soils and am fungal communities. our results indicate that andropogon ecotypes adapt to their local s ... | 2010 | 20133855 |
| effects of n on plant response to heat-wave: a field study with prairie vegetation. | more intense, more frequent, and longer heat-waves are expected in the future due to global warming, which could have dramatic ecological impacts. increasing nitrogen (n) availability and its dynamics will likely impact plant responses to heat stress and carbon (c) sequestration in terrestrial ecosystems. this field study examined the effects of n availability on plant response to heat-stress (hs) treatment in naturally-occurring vegetation. hs (5 d at ambient or 40.5 degrees c) and n treatments ... | 2008 | 19017129 |
| effect of elevated co2 and drought on soil microbial communities associated with andropogon gerardii. | our understanding of the effects of elevated atmospheric co2, singly and in combination with other environmental changes,on plant-soil interactions is incomplete. elevated co2 effects on c4 plants, though smaller than on c3 species, are mediated mostly via decreased stomatal conductance and thus water loss. therefore, we characterized the interactive effect of elevated co2 and drought on soil microbial communities associated with a dominant c4 prairie grass, andropogon gerardii vitman. elevated ... | 2008 | 19017128 |
| topsin-m: the new benomyl for mycorrhizal-suppression experiments. | the fungicide benomyl was the most commonly used biocide for both field and greenhouse experiments in which arbuscular mycorrhizal fungal (amf) suppression is desired. unfortunately benomyl is no longer manufactured and therefore is not available for experimental use and no fungicide has been proposed as a successful alternative for experimentally suppressing mycorrhizal fungi. in this study we examined the potential for the fungicide topsin m (topsin) to suppress mycorrhizal symbiosis in both f ... | 2013 | 18833748 |
| plant-soil feedback: testing the generality with the same grasses in serpentine and prairie soils. | plants can alter soil properties in ways that feed back to affect plant performance. the extent that plant-soil feedback affects co-occurring plant species differentially will determine its impact on plant community structure. whether feedback operates consistently across similar plant communities is little studied. here, the same grasses from two eastern u.s. serpentine grasslands and two midwestern tallgrass prairie remnants were examined for plant-soil feedback in parallel greenhouse experime ... | 2008 | 18724725 |
| selection of plants for optimization of vegetative filter strips treating runoff from turfgrass. | runoff from turf environments, such as golf courses, is of increasing concern due to the associated chemical contamination of lakes, reservoirs, rivers, and ground water. pesticide runoff due to fungicides, herbicides, and insecticides used to maintain golf courses in acceptable playing condition is a particular concern. one possible approach to mitigate such contamination is through the implementation of effective vegetative filter strips (vfs) on golf courses and other recreational turf enviro ... | 2008 | 18689747 |
| evaluating plant-soil feedback together with competition in a serpentine grassland. | plants can alter biotic and abiotic soil characteristics in ways that feedback to change the performance of that same plant species relative to co-occurring plants. most evidence for this plant-soil feedback comes from greenhouse studies of potted plants, and consequently, little is known about the importance of feedback in relation to other biological processes known to structure plant communities, such as plant-plant competition. in a field experiment with three c4 grasses, negative feedback w ... | 2007 | 17498138 |
| reactive oxygen species, aba and nitric oxide interactions on the germination of warm-season c4-grasses. | hydrogen peroxide (h(2)o(2)) as a source of reactive oxygen species (ros) significantly stimulated germination of switchgrass (panicum virgatum l.) seeds with an optimal concentration of 20 mm at both 25 and 35 degrees c. for non-dormant switchgrass seeds exhibiting different levels of germination, treatment with h(2)o(2) resulted in rapid germination (<3 days) of all germinable seeds as compared to seeds placed on water. exposure to 20 mm h(2)o(2) elicited simultaneous growth of the root and sh ... | 2007 | 17431667 |
| the effect of co(2) enrichment on leaf photosynthetic rates and instantaneous water use efficiency of andropogon gerardii in the tallgrass prairie. | open-top chambers were used to study the effects of co(2) enrichment on leaf-level photosynthetic rates of the c(4) grass andropogon gerardii in the native tallgrass prairie ecosystem near manhattan, kansas. measurements were made during a year with abundant rainfall (1993) and a year with below-normal rainfall (1994). treatments included: no chamber, ambient co(2) (a); chamber with ambient co(2) (ca); and chamber with twice-ambient co(2) (ce). measurements of photosynthesis were made at 2-hour ... | 2000 | 16228479 |
| productivity responses to altered rainfall patterns in a c4-dominated grassland. | rainfall variability is a key driver of ecosystem structure and function in grasslands worldwide. changes in rainfall patterns predicted by global climate models for the central united states are expected to cause lower and increasingly variable soil water availability, which may impact net primary production and plant species composition in native great plains grasslands. we experimentally altered the timing and quantity of growing season rainfall inputs by lengthening inter-rainfall dry interv ... | 2003 | 12845518 |
| c3 woody plant expansion in a c4 grassland: are grasses and shrubs functionally distinct? | the expansion of c(3) shrubs into c(4)-dominated tallgrass prairies represents a fundamental shift in growth-form dominance accompanied by changes in resource acquisition and use. we assessed these changes by comparing the ecophysiological traits of the dominant c(4) grass andropogon gerardii, with traits of three c(3) invasive shrub species, cornus drummondii, prunus americana, and rhus glabra. we tested the hypothesis that ecophysiological traits of the shrubs would be similar within this grow ... | 2001 | 21669615 |
| evidence of a mycorrhizal mechanism for the adaptation of andropogon gerardii (poaceae) to high- and low-nutrient prairies. | andropogon gerardii seed obtained from kansas and illinois was grown in a controlled environment in their own and each other's soils, with and without arbuscular mycorrhizal fungi (amf). each ecotype grew comparatively better in its own soil indicating adaptation to its soil of origin. overall, a. gerardii benefited more from amf in low-nutrient kansas soil than illinois soil. the two ecotypes, however, did not benefit equally from mycorrhizal infection. the kansas ecotype was three times more r ... | 2001 | 21669699 |
| random amplified polymorphic dna variation among remnant big bluestem (andropogon gerardii vitman) populations from arkansas' grand prairie | random amplified polymorphic dna (rapd) analysis was used to characterize genetic diversity and genetic distinctiveness of andropogon gerardii from remnant arkansas prairies. six oligonucleotide primers, which generated 37 rapd bands, were used to analyse 30-32 plants from six grand prairie populations, baker prairie (arkansas ozarks), two illinois prairies and two cultivars. genetic diversity of the arkansas remnants ranged from 82.7 to 99.3%, with 89% of the total genetic variation within and ... | 1999 | 10583832 |
| interacting influence of mycorrhizal symbiosis and competition on plant diversity in tallgrass prairie. | in tallgrass prairie, plant species interactions regulated by their associated mycorrhizal fungi may be important forces that influence species coexistence and community structure; however, the mechanisms and magnitude of these interactions remain unknown. the objective of this study was to determine how interspecific competition, mycorrhizal symbiosis, and their interactions influence plant community structure. we conducted a factorial experiment, which incorporated manipulations of abundance o ... | 1999 | 28308367 |
| elevated co22 and leaf longevity in the c44 grassland-dominant andropogon gerardii. | in central u.s. grasslands, plant and ecosystem responses to elevated co2 are most pronounced when water availability is limited. in a northeast kansas grassland, responses to elevated co2 in leaf area, number, development, and longevity were quantified for the tallgrass prairie dominant, andropogon gerardii. plants were grown in open-top chambers (otcs) modified to limit water availability and to maximize responses to elevated co2. in otcs with elevated (x2 ambient) levels of co2, aboveground b ... | 1999 | 10568772 |
| comparison of common cytotypesof andropogon gerardii(andropogoneae, poaceae). | many plant species contain populations with more than one polyploid cytotype, but little is known of the mechanisms maintaining several cytotypes in a population. andropogon gerardii cytotypes were compared to evaluate different models of autopolyploid cytotype coexistence. the enneaploid (90 chromosome, 9x) cytotype was found to be larger and taller than the hexaploid (60 chromosome, 6x) cytotype. seed production is significantly more efficient in hexaploids, but seed production per area was no ... | 1999 | 10406720 |
| reproductive biology of two dominant prairie grasses (andropogon gerardii and sorghastrum nutans, poaceae): male-biased sex allocation in wind-pollinated plants? | it has been proposed that some wind-pollinated plants have the necessary conditions for an optimal sex allocation that is male biased, though there are few data that address this prediction. we determined that two prairie grass species (andropogon gerardii and sorghastrum nutans) had reproductive characteristics that theoretically would result in a male-biased allocation: both species were self-incompatible and neither species had increased seed set after supplemental hand pollination. the relat ... | 1998 | 21684961 |
| evolutionary implications of meiotic chromosome behavior, reproductive biology, and hybridization in 6x and 9x cytotypes of andropogon gerardii (poaceae). | andropogon gerardii, big bluestem, has 60 and 90 chromosome cytotypes. meiosis in the hexaploid was shown to be regular, although some secondary associations of bivalents form. meiosis in the enneaploid (2n = 9z = 90) is irregular, leading to most gametes having unbalanced chromosome complements. both cytotypes show considerable self-incompatibility. cytotypes crossed freely, forming a variety of fertile euploids and aneuploids. indistinguishable exomorphology, intermixing in natural populations ... | 1997 | 21712199 |
| contribution of flexible allocation priorities to herbivory tolerance in c4 perennial grasses: an evaluation with (13)c labeling. | the ability of plants to rapidly replace photosynthetic tissues following defoliation represents a resistance strategy referred to as herbivory tolerance. rapid reprioritization of carbon allocation to regrowing shoots at the expense of roots following defoliation is a widely documented tolerance mechanism. an experiment was conducted in a controlled environment to test the hypothesis that herbivory-sensitive perennial grasses display less flexibility in reprioritizing carbon allocation in respo ... | 1996 | 28307076 |
| ammonia volatilization during drought in perennial c4 grasses of tallgrass prairie. | we measured foliar nh3 volatilization as part of our study of the decrease (up to 40%) in shoot n concentration during drought in three perennial c4 grasses of tallgrass prairie. volatilization of recently expanded leaves was quantified using cuvettes and acid traps for spartina pectinata, andropogon gerardii, and schizachyrium scoparium, a mesic, intermediate, and xeric species, respectively. in general, volatilization decreased during drought, approaching zero as stomates closed, and increased ... | 1995 | 28307058 |
| effects of mycorrhizae and fertilizer amendments on zinc tolerance of plants. | in soils containing elevated levels of zinc, plant growth may be impaired because of zn interference with p uptake by plants and because of detrimental effects of zn toxicity itself. because mycorrhizal fungi are known to improve uptake of plant p, the beneficial effects of mycorrhizal symbiosis on zn tolerance of andropogon gerardii vitm. were assessed in soil amended with various levels of zn and p. in the absence of p amendment, mycorrhizal fungi stimulated plant growth, but the degree of ben ... | 1995 | 15091543 |
| plant demographic responses to mycorrhizal symbiosis in tallgrass prairie. | the effects of mycorrhizal symbiosis on seedling emergence, flowering and densities of several grasses and forbs were assessed in native tallgrass prairie and in sown garden populations at the konza prairie in northeastern kansas. mycorrhizal activity was experimentally suppressed with the fungicide benomyl. flowering and stem densities of the cool-season grass, dichanthelium oligosanthes, sedges (carex spp.), and the forb aster ericoides were higher in non-mycorrhizal (benomyl-treated) than in ... | 1994 | 28313944 |
| effects of mycorrhizae and other soil microbes on revegetation of heavy metal contaminated mine spoil. | the effects of mycorrhizal fungi and other soil microorganisms on growth of two grasses, andropogon gerardii vitm. and festuca arundinacea schreb., in heavy metal-contaminated soil and mine tailings were investigated. a. gerardii is highly dependent on mycorrhizal fungi in native prairie, while f. arundinacea is a facultative mycotroph and relies on mycorrhizal symbiosis only in extremely infertile soils. regardless of microbial amendments, neither plant species was able to establish and grow in ... | 1994 | 15091635 |
| the influence of mycorrhizal symbiosis and fertilizer amendments on establishment of vegetation in heavy metal mine spoil. | biomass production of andropogon gerardii and festuca arundinacea was assessed in mine tailings (chat), a material containing high levels of zinc. the effects of organic and inorganic fertilizer amendments, the addition of an expanded clay material, and mycorrhizal fungi on the revegetation of chat were assessed. plant growth in chat was best with mycorrhizal inoculation combined with nitrogen (either organic or inorganic) and phosphorus fertilization. plant growth was also achieved if the chat ... | 1994 | 15091634 |
| biomass production in a tallgrass prairie ecosystem exposed to ambient and elevated co"2. | responses to elevated co"2 have not been measured for natural grassland ecosystems. global carbon budgets will likely be affected by changes in biomass production and allocation in the major terrestrial ecosystems. whether ecosystems sequester or release excess carbon to the atmosphere will partly determine the extent and rate that atmospheric co"2 concentration rises. elevated co"2 also may change plant community species composition and water status. we determined above- and belowground biomass ... | 1993 | 27759286 |
| effects of bison grazing on andropogon gerardii and panicum virgatum in burned and unburned tallgrass paririe. | responses to clipping and bison grazing in different environmental contexts were examined in two perennial grass species, andropogon gerardii and panicum virgatum, on the konza prairie in northeastern kansas. grazed tillers had lower relative growth rates (rgr) than clipped tillers following defoliation but this difference was transient and final biomass was not affected by mode of defoliation. grazed tillers of both species had higher rgr throughout the season than ungrazed tillers, resulting i ... | 1992 | 28313524 |
| controls of nitrogen limitation in tallgrass prairie. | the relationship between fire frequency and n limitation to foliage production in tallgrass prairie was studied with a series of fire and n addition experiments. results indicated that fire history affected the magnitude of the vegetation response to fire and to n additions. sites not burned for over 15 years averaged only a 9% increase in foliage biomass in response to n enrichment. in contrast, foliage production increased an average of 68% in response to n additions on annually burned sites, ... | 1991 | 28313354 |
| density- and growth stage-dependent responses to defoliation in two rhizomatous grasses. | responses to defoliation were studied in two tallgrass prairie perennials (andropogon gerardii and panicum virgatum) established from seed at three densities. p. virgatum was also grown from transplanted rhizomes of established clones. plants of both species displayed a continuum of responses to defoliation, from large reductions in biomass, tillering and seed production to significant increases in one or more performance measures. in crowded populations, defoliation shifted plants into subordin ... | 1989 | 28312071 |
| the use of stable carbon isotope analysis in rooting studies. | stable carbon isotope analysis was evaluated as a means of predicting the relative proportions of c3 and c4 root phytomass in species mixtures. the following mixtures of c3 and c4 species were used: 1) big bluestem (andropogon gerardii)/cheatgrass (bromus tectorum), 2) little bluestem (schizachyrium scoparium)/cheatgrass, and 3) sorghum (sorghum bicolor)/sunflower (helianthus annuus). there was a significant correlation (p<0.01) between % c4 phytomass and stable carbon isotope values for each of ... | 1985 | 28311309 |
| water relations and growth of three grasses during wet and drought years in a tallgrass prairie. | the water relations and growth of three tallgrass prairie species panicum virgatum, andropogon gerardii and a. scoparius were examined in irrigated and unwatered prairie in eastern kansas (usa). measurements of the osmotic potential at full turgor, ψ π(100) , at zero turgor, ψ(0), and growth of vegetative and reproductive tillers were made in a year with above-normal precipitation and a drought year to evaluate: 1) the ability of these grasses to osmotically adjust in response to water stress an ... | 1984 | 28312107 |
| investigations of trypsin inhibitors in leaves of four north american prairie grasses. | leaves of four important north american prairie grasses (agropyron smithii, andropogon gerardii, a. scoparius, and bouteloua gracilis) were examined for the presence of trypsin inhibitors which are thought to protect some plant species from herbivory. leaves of all four species had significant inhibitor activity at levels comparable to those in tomato leaves. our evidence suggests that part of the inhibitor activity was proteinaceous and part may have been polyphenolic. young leaves ofa. smithii ... | 1983 | 24407343 |