WorldWideScience

Sample records for grassland plant identification

  1. Spectral identification of plant communities for mapping of semi-natural grasslands

    DEFF Research Database (Denmark)

    Jacobsen, Anne; Nielsen, Allan Aasbjerg; Ejrnæs, Rasmus

    2000-01-01

    identification of plant communities was based on a hierarchical approach relating the test sites to i) management (Ma) and ii) flora (Fl) using spectral consistency and separability as the main criteria. Evaluation of spectral consistency was based on unsupervised clustering of test sites of Ma classes 1 to 7...... as a measure of plant community heterogeneity within management classes. The spectral analysis as well as the maximum likelihood classification indicated that the source of spectral variation within management classes might be related to vegetation composition....

  2. Description and identification of four species of plant parasitic nematodes associated with grassland, fruit trees and maize in Romania.

    Science.gov (United States)

    Badi, M; Geraert, E

    2002-01-01

    Three species of plant parasitic nematodes present in two romanian soil samples were described and identified in the present study. The species belong to order tylenchida and to taxonomical families Tylenchidae (Basiria aberrans) and Belonolaimidae (Tylenchorhynchus georgiensis and Merlinius brevidens). The identification of the present specimens was based on the classical taxonomy, following morphological and morphometrical characters in the species specific identification keys.

  3. Acidification of sandy grasslands - consequences for plant diversity

    DEFF Research Database (Denmark)

    Olsson, Pål Axel; Mårtensson, Linda-Maria; Bruun, Hans Henrik

    2009-01-01

    soil; a number of nationally red-listed species showed a similar pattern. Plant species diversity and number of red-listed species increased with slope. Where the topsoil had been acidified, limestone was rarely present above a depth of 30 cm. The presence of limestone restricts the availability......Questions: (1) Does soil acidification in calcareous sandy grasslands lead to loss of plant diversity? (2) What is the relationship between the soil content of lime and the plant availability of mineral nitrogen (N) and phosphorus (P) in sandy grasslands? Location: Sandy glaciofluvial deposits......). Environmental variables were recorded at each plot, and soil samples were analysed for exchangeable P and N, as well as limestone content and pH. Data were analysed with regression analysis and canonical correspondence analysis. Results: Plant species richness was highest on weakly acid to slightly alkaline...

  4. Herbivores and nutrients control grassland plant diversity via light limitation

    Science.gov (United States)

    Borer, Elizabeth T.; Seabloom, Eric W.; Gruner, Daniel S.; Harpole, W. Stanley; Hillebrand, Helmut; Lind, Eric M.; Alder, Peter B.; Alberti, Juan; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori; Blumenthal, Dana; Brown, Cynthia S.; Brudvig, Lars A.; Buckley, Yvonne M.; Cadotte, Marc; Chu, Cheng-Jin; Cleland, Elsa E.; Crawley, Michael J.; Daleo, Pedro; Damschen, Ellen Ingman; Davies, Kendi F.; DeCrappeo, Nicole M.; Du, Guozhen; Firn, Jennifer; Hautier, Yann; Heckman, Robert W.; Hector, Andy; HilleRisLambers, Janneke; Iribarne, Oscar; Klein, Julia A.; Knops, Johannes M.H.; La Pierre, Kimberly J.; Leakey, Andrew D.B.; Li, Wei; MacDougall, Andrew S.; McCulley, Rebecca L.; Melbourne, Brett A.; Mitchell, Charles E.; Moore, Joslin L.; Mortensen, Brent; O'Halloran, Lydia R.; Orrock, John L.; Pascual, Jesús; Prober, Suzanne M.; Pyke, David A.; Risch, Anita C.; Schuetz, Martin; Smith, Melinda D.; Stevens, Carly J.; Sullivan, Lauren L.; Williams, Ryan J.; Wragg, Peter D.; Wright, Justin P.; Yang, Louie H.

    2014-01-01

    Human alterations to nutrient cycles and herbivore communities are affecting global biodiversity dramatically. Ecological theory predicts these changes should be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive exclusion by increasing ground-level light, particularly in productive systems. Here we use experimental data spanning a globally relevant range of conditions to test the hypothesis that herbaceous plant species losses caused by eutrophication may be offset by increased light availability due to herbivory. This experiment, replicated in 40 grasslands on 6 continents, demonstrates that nutrients and herbivores can serve as counteracting forces to control local plant diversity through light limitation, independent of site productivity, soil nitrogen, herbivore type and climate. Nutrient addition consistently reduced local diversity through light limitation, and herbivory rescued diversity at sites where it alleviated light limitation. Thus, species loss from anthropogenic eutrophication can be ameliorated in grasslands where herbivory increases ground-level light.

  5. Nitrogen acquisition by plants and microorganisms in a temperate grassland.

    Science.gov (United States)

    Liu, Qianyuan; Qiao, Na; Xu, Xingliang; Xin, Xiaoping; Han, Jessie Yc; Tian, Yuqiang; Ouyang, Hua; Kuzyakov, Yakov

    2016-03-10

    Nitrogen (N) limitation is common in most terrestrial ecosystems, often leading to strong competition between microorganisms and plants. The mechanisms of niche differentiation to reduce this competition remain unclear. Short-term (15)N experiments with NH4(+), NO3(-), and glycine were conducted in July, August and September in a temperate grassland to evaluate the chemical, spatial and temporal niche differentiation by competition between plants and microorganisms for N. Microorganisms preferred NH4(+) and NO3(-), while plants preferred NO3(-). Both plants and microorganisms acquired more N in August and September than in July. The soil depth had no significant effects on microbial uptake, but significantly affected plant N uptake. Plants acquired 67% of their N from the 0-5 cm soil layer and 33% from the 5-15 cm layer. The amount of N taken up by microorganisms was at least seven times than plants. Although microorganisms efficiently compete for N with plants, the competition is alleviated through chemical partitioning mainly in deeper soil layer. In the upper soil layer, neither chemical nor temporal niche separation is realized leading to strong competition between plants and microorganisms that modifies N dynamics in grasslands.

  6. Temporal dynamics of soil nematode communities in a grassland plant diversity experiment.

    NARCIS (Netherlands)

    Viketoft, M.; Sohlenius, B.; Bostrom, S.; Palmborg, C.; Bengtsson, J.; Berg, M.P.; Kuss-Danell, K.

    2011-01-01

    We report here on an 8-year study examining links between plant and nematode communities in a grassland plant diversity experiment, located in the north of Sweden on previous agricultural soil. The examined plots contained 1, 4 and 12 common grassland plant species from three functional groups;

  7. Plant Transporter Identification

    DEFF Research Database (Denmark)

    Larsen, Bo

    Membrane transport proteins (transporters) play a critical role for numerous biological processes, by controlling the movements of ions and molecules in and out of cells. In plants, transporters thus function as gatekeepers between the plant and its surrounding environment and between organs......, tissues, cells and intracellular compartments. Since plants are highly compartmentalized organisms with complex transportation infrastructures, they consequently have many transporters. However, the vast majority of predicted transporters have not yet been experimentally verified to have transport...... activity. This project contains a review of the implemented methods, which have led to plant transporter identification, and present our progress on creating a high-throughput functional genomics transporter identification platform....

  8. Seasonal dynamics and vertical distribution of plant-feeding nematode communities in grasslands

    NARCIS (Netherlands)

    Verschoor, B.C.; Goede, de R.G.M.; Hoop, de J.W.; Vries, de F.W.

    2001-01-01

    The vertical distribution and seasonal dynamics of plant- and fungal-feeding nematode taxa in permanent grasslands were investigated. Dolichodoridae, Paratylenchus, Pratylenchus, Tylenchidae and Aphelenchoides dominated the upper 10 cm soil and their numbers strongly decreased with depth. The

  9. Plant species occurrence patterns in Eurasian grasslands reflect adaptation to nutrient ratios

    NARCIS (Netherlands)

    Roeling, Ineke S.; Ozinga, Wim A.; van Dijk, Jerry; Eppinga, Maarten B.; Wassen, Martin J.

    2018-01-01

    Previous studies of Eurasian grasslands have suggested that nutrient ratios, rather than absolute nutrient availabilities and associated productivity, may be driving plant species richness patterns. However, the underlying assumption that species occupy distinct niches along nutrient ratio gradients

  10. Plutonium in a grassland ecosystem. [Rocky Flats Plant

    Energy Technology Data Exchange (ETDEWEB)

    Little, C.A.

    1976-08-01

    A study was made of plutonium contamination of grassland at the Rocky Flats plant northwest of Denver, Colorado. Of interest were: the definition of major plutonium-containing ecosystem compartments; the relative amounts in those compartments; how those values related to studies done in other geographical areas; whether or not the predominant isotopes, /sup 238/Pu and /sup 239/Pu, behaved differently; and what mechanisms might have allowed for the observed patterns of contamination. Samples of soil, litter, vegetation, arthropods, and small mammals were collected for Pu analysis and mass determination from each of two macroplots. Small aliquots (5 g or less) were analyzed by a rapid liquid scintillation technique and by alpha spectrometry. Of the compartments sampled, greater than 99 percent of the total plutonium was contained in the soil and the concentrations were significantly inversely correlated with distance from the contamination source, depth of the sample, and particle size of the sieved soil samples. The soil data suggested that the distribution of contamination largely resulted from physical transport processes.

  11. Long-term effects of plant diversity and composition on soil nematode communities in grassland.

    NARCIS (Netherlands)

    Viketoft, M.; Bengtsson, J.; Sohlenius, B.; Berg, M.P.; Petchey, O.; Palmborg, C.; Huss-Daniel, K.

    2009-01-01

    An important component of plant-soil feedbacks is how plant species identity and diversity influence soil organism communities. We examine the effects of grassland plant species growing alone and together up to a richness of 12 species on nematode diversity and feeding group composition, eight years

  12. Specialist plant species harbour higher reproductive performances in recently restored calcareous grasslands than in reference habitats

    OpenAIRE

    Harzé, Mélanie; Mahy, Grégory; Bizoux, Jean-Philippe; Piqueray, Julien; Monty, Arnaud

    2015-01-01

    Background and aims_Calcareous grasslands are local biodiversity hotspots in temperate regions that suffered intensive fragmentation. Ecological restoration projects took place all over Europe. Their success has traditionally been assessed using a plant community approach. However, population ecology can also be useful to assess restoration success and to understand underlying mechanisms. Methods_We took advantage of three calcareous grassland sites in Southern Belgium, where reference p...

  13. Extensive Management Promotes Plant and Microbial Nitrogen Retention in Temperate Grassland

    Science.gov (United States)

    de Vries, Franciska T.; Bloem, Jaap; Quirk, Helen; Stevens, Carly J.; Bol, Roland; Bardgett, Richard D.

    2012-01-01

    Leaching losses of nitrogen (N) from soil and atmospheric N deposition have led to widespread changes in plant community and microbial community composition, but our knowledge of the factors that determine ecosystem N retention is limited. A common feature of extensively managed, species-rich grasslands is that they have fungal-dominated microbial communities, which might reduce soil N losses and increase ecosystem N retention, which is pivotal for pollution mitigation and sustainable food production. However, the mechanisms that underpin improved N retention in extensively managed, species-rich grasslands are unclear. We combined a landscape-scale field study and glasshouse experiment to test how grassland management affects plant and soil N retention. Specifically, we hypothesised that extensively managed, species-rich grasslands of high conservation value would have lower N loss and greater N retention than intensively managed, species-poor grasslands, and that this would be due to a greater immobilisation of N by a more fungal-dominated microbial community. In the field study, we found that extensively managed, species-rich grasslands had lower N leaching losses. Soil inorganic N availability decreased with increasing abundance of fungi relative to bacteria, although the best predictor of soil N leaching was the C/N ratio of aboveground plant biomass. In the associated glasshouse experiment we found that retention of added 15N was greater in extensively than in intensively managed grasslands, which was attributed to a combination of greater root uptake and microbial immobilisation of 15N in the former, and that microbial immobilisation increased with increasing biomass and abundance of fungi. These findings show that grassland management affects mechanisms of N retention in soil through changes in root and microbial uptake of N. Moreover, they support the notion that microbial communities might be the key to improved N retention through tightening linkages

  14. Simulation of the decomposition and nitrogen mineralization of aboveground plant material in two unfertilized grassland ecosystems.

    NARCIS (Netherlands)

    Bloemhof, H.S.; Berendse, F.

    1995-01-01

    A simple model of the decomposition and nitrogen mineralization of plant material from two unfertilized grassland ecosystems has been developed, with only the proportion of leaves and stems in the original material, the initial nitrogen contents of these plant parts and temperature as input data.

  15. The Effects of Timing of Grazing on Plant and Arthropod Communities in High-Elevation Grasslands

    Science.gov (United States)

    Davis, Stacy C.; Burkle, Laura A.; Cross, Wyatt F.; Cutting, Kyle A.

    2014-01-01

    Livestock grazing can be used as a key management tool for maintaining healthy ecosystems. However, the effectiveness of using grazing to modify habitat for species of conservation concern depends on how the grazing regime is implemented. Timing of grazing is one grazing regime component that is less understood than grazing intensity and grazer identity, but is predicted to have important implications for plant and higher trophic level responses. We experimentally assessed how timing of cattle grazing affected plant and arthropod communities in high-elevation grasslands of southwest Montana to better evaluate its use as a tool for multi-trophic level management. We manipulated timing of grazing, with one grazing treatment beginning in mid-June and the other in mid-July, in two experiments conducted in different grassland habitat types (i.e., wet meadow and upland) in 2011 and 2012. In the upland grassland experiment, we found that both early and late grazing treatments reduced forb biomass, whereas graminoid biomass was only reduced with late grazing. Grazing earlier in the growing season versus later did not result in greater recovery of graminoid or forb biomass as expected. In addition, the density of the most ubiquitous grassland arthropod order (Hemiptera) was reduced by both grazing treatments in upland grasslands. A comparison of end-of-season plant responses to grazing in upland versus wet meadow grasslands revealed that grazing reduced graminoid biomass in the wet meadow and forb biomass in the upland, irrespective of timing of grazing. Both grazing treatments also reduced end-of-season total arthropod and Hemiptera densities and Hemiptera biomass in both grassland habitat types. Our results indicate that both early and late season herbivory affect many plant and arthropod characteristics in a similar manner, but grazing earlier may negatively impact species of conservation concern requiring forage earlier in the growing season. PMID:25338008

  16. Does resource availability, resource heterogeneity or species turnover mediate changes in plant species richness in grazed grasslands?

    NARCIS (Netherlands)

    Bakker, C; Blair, JM; Knapp, AK

    2003-01-01

    Grazing by large ungulates often increases plant species richness in grasslands of moderate to high productivity. In a mesic North American grassland with and without the presence of bison (Bos bison), a native ungulate grazer, three non-exclusive hypotheses for increased plant species richness in

  17. Impact of weather on dynamics of plant functional groups in an abandoned limestone grassland

    Directory of Open Access Journals (Sweden)

    Zbigniew Dzwonko

    2011-12-01

    Full Text Available We examined to what extend the rate and direction of changes in unmanaged grassland depend on fluctuations in climatic conditions. Vegetation data from permanent plots in a semi-natural grassland in southern Poland collected over 12 years were used. Relations between weather variables, time, and the cover of 41 more frequent species and 14 plant functional groups were analysed. The greatest effect on the dynamics of species and functional groups had precipitation in spring and/or early summer, particularly in the current year. The majority of plant groups were significantly affected also by the temperature in spring and early summer in one of the three previous years. During 12 years, the cover of annuals and biennials, short plants, and plants with small leaves decreased, while the cover of taller plants, plants with larger leaves, and with vegetative spread increased. The analyses suggest that these successional changes were not directly associated with climatic conditions but were affected by them indirectly through interspecific competition. The fluctuations in climatic conditions, chiefly precipitation, had a significant effect on both the composition and the rate of changes in abandoned grassland. The increase in the cover of tall perennial species with broad leaves hindered succession towards woodland despite of the presence of woods in the closed vicinity. It can be expected that during drier periods colonisation of grassland by later successional species could be easier.

  18. Plant diversity predicts beta but not alpha diversity of soil microbes across grasslands worldwide

    Science.gov (United States)

    Prober, Suzanne M.; Leff, Jonathan W.; Bates, Scott T.; Borer, Elizabeth T.; Firn, Jennifer; Harpole, W. Stanley; Lind, Eric M.; Seabloom, Eric W.; Adler, Peter B.; Bakker, Jonathan D.; Cleland, Elsa E.; DeCrappeo, Nicole; DeLorenze, Elizabeth; Hagenah, Nicole; Hautier, Yann; Hofmockel, Kirsten S.; Kirkman, Kevin P.; Knops, Johannes M. H.; La Pierre, Kimberly J.; MacDougall, Andrew S.; McCulley, Rebecca L.; Mitchell, Charles E.; Risch, Anita C.; Schuetz, Martin; Stevens, Carly J.; Williams, Ryan J.; Fierer, Noah

    2015-01-01

    Aboveground–belowground interactions exert critical controls on the composition and function of terrestrial ecosystems, yet the fundamental relationships between plant diversity and soil microbial diversity remain elusive. Theory predicts predominantly positive associations but tests within single sites have shown variable relationships, and associations between plant and microbial diversity across broad spatial scales remain largely unexplored. We compared the diversity of plant, bacterial, archaeal and fungal communities in one hundred and forty-five 1 m2 plots across 25 temperate grassland sites from four continents. Across sites, the plant alpha diversity patterns were poorly related to those observed for any soil microbial group. However, plant beta diversity (compositional dissimilarity between sites) was significantly correlated with the beta diversity of bacterial and fungal communities, even after controlling for environmental factors. Thus, across a global range of temperate grasslands, plant diversity can predict patterns in the composition of soil microbial communities, but not patterns in alpha diversity.

  19. Experimental effects of herbivore density on above-ground plant biomass in an alpine grassland ecosystem

    OpenAIRE

    Austrheim, Gunnar; Speed, James David Mervyn; Martinsen, Vegard; Mulder, Jan; Mysterud, Atle

    2014-01-01

    Herbivores may increase or decrease aboveground plant productivity depending on factors such as herbivore density and habitat productivity. The grazing optimization hypothesis predicts a peak in plant production at intermediate herbivore densities, but has rarely been tested experimentally in an alpine field setting. In an experimental design with three densities of sheep (high, low, and no sheep), we harvested aboveground plant biomass in alpine grasslands prior to treatment and after five y...

  20. Woody plant encroachment of grasslands: a comparison of terrestrial and wetland settings.

    Science.gov (United States)

    Saintilan, Neil; Rogers, Kerrylee

    2015-02-01

    A global trend of woody plant encroachment of terrestrial grasslands is co-incident with woody plant encroachment of wetland in freshwater and saline intertidal settings. There are several arguments for considering tree encroachment of wetlands in the context of woody shrub encroachment of grassland biomes. In both cases, delimitation of woody shrubs at regional scales is set by temperature thresholds for poleward extent, and by aridity within temperature limits. Latitudinal expansion has been observed for terrestrial woody shrubs and mangroves, following recent warming, but most expansion and thickening has been due to the occupation of previously water-limited grassland/saltmarsh environments. Increases in atmospheric CO₂, may facilitate the recruitment of trees in terrestrial and wetland settings. Improved water relations, a mechanism that would predict higher soil moisture in grasslands and saltmarshes, and also an enhanced capacity to survive arid conditions, reinforces local mechanisms of change. The expansion of woody shrubs and mangroves provides a negative feedback on elevated atmospheric CO₂ by increasing carbon sequestration in grassland and saltmarsh, and is a significant carbon sink globally. These broad-scale vegetation shifts may represent a new stable state, reinforced by positive feedbacks between global change drivers and endogenic mechanisms of persistence in the landscape.

  1. Dissimilar response of plant and soil biota communities to long-term nutrient adition in grasslands

    NARCIS (Netherlands)

    Wal, van der A.; Geerts, R.H.E.M.; Korevaar, H.; Schouten, A.J.; Jagers op Akkerhuis, G.A.J.M.; Rutgers, M.; Mulder, C.

    2009-01-01

    The long-term effect of fertilizers on plant diversity and productivity is well known, but long-term effects on soil biota communities have received relatively little attention. Here, we used an exceptional long-lasting (>40 years) grassland fertilization experiment to investigate the long-term

  2. DIVERSITY OF PLANT COMMUNITIES IN SECONDARY SUCCESSION OF IMPERATA GRASSLANDS IN SAMBOJA LESTARI, EAST KALIMANTAN, INDONESIA

    Directory of Open Access Journals (Sweden)

    Ishak Yassir

    2016-06-01

    Full Text Available Regeneration of  Imperata grassland areas is becoming increasingly important, both to create new secondary forest and to recover the original biodiversity. The diversity of  plant communities in secondary succession of  Imperata grasslands was studied using 45 subplots of  9 linear transects (10 m x 100 m. Data was collected and all stems over 10 cm dbh were identified, the Importance Values Index (IVI for all trees were calculated, saplings and seedlings were counted  and analysed, and soil samples were taken and analysed. Results showed that  after more than 10 years of  regeneration, 65 families were encountered consisting of  164 species, which were dominated by Vernonia arborea Buch.-Ham, Vitex pinnata L., Macaranga gigantea (Reichb.f. & Zoll. Muell.Arg., Symplocos crassipes C.B. Clarke, Artocarpus odoratissimus Miq., and Bridelia glauca Blume. The effects of  regeneration, from Imperata grassland to secondary forest, on soil were the strongest in the A-horizon where an increase in carbon, N content, and pH were observed. Our result shows that Imperata grasslands appear to be permanent because of  frequent fires and human interferences and so far few efforts have been made to promote sustainable rehabilitation. If  protected from fire and other disturbances, such as shifting cultivation, Imperata grassland will grow and develop into secondary forest.

  3. Ecosystem development in roadside grasslands: Biotic control, plant-soil interactions, and dispersal limitations

    Science.gov (United States)

    Garcia-Palacios, P.; Bowker, M.A.; Maestre, F.T.; Soliveres, S.; Valladares, F.; Papadopoulos, J.; Escudero, A.

    2011-01-01

    Roadside grasslands undergoing secondary succession are abundant, and represent ecologically meaningful examples of novel, human-created ecosystems. Interactions between plant and soil communities (hereafter plant-soil interactions) are of major importance in understanding the role of biotic control in ecosystem functioning, but little is known about these links in the context of ecosystem restoration and succession. The assessment of the key biotic communities and interactions driving ecosystem development will help practitioners to better allocate the limited resources devoted to roadside grassland restoration. We surveyed roadside grasslands from three successional stages (0-2, 7-9, and > 20 years) in two Mediterranean regions of Spain. Structural equation modeling was used to evaluate how interactions between plants, biological soil crusts (BSCs), and soil microbial functional diversity (soil microorganisms) affect indicators of ecosystem development and restoration: plant similarity to the reference ecosystem, erosion control, and soil C storage and N accumulation. Changes in plant community composition along the successional gradient exerted the strongest influence on these indicators. High BSC cover was associated with high soil stability, and high soil microbial functional diversity from late-successional stages was associated with high soil fertility. Contrary to our expectations, the indirect effects of plants, mediated by either BSCs or soil microorganisms, were very weak in both regions, suggesting a minor role for plant-soil interactions upon ecosystem development indicators over long periods. Our results suggest that natural vegetation dynamics effectively improved ecosystem development within a time frame of 20 years in the grasslands evaluated. They also indicate that this time could be shortened if management actions focus on: (1) maintaining wellconserved natural areas close to roadsides to enhance plant compositional changes towards late

  4. Mapping Plant Functional Groups in Subalpine Grassland of the Greater Caucasus

    Directory of Open Access Journals (Sweden)

    Anja Magiera

    2018-02-01

    Full Text Available Plant functional groups—in our case grass, herbs, and legumes—and their spatial distribution can provide information on key ecosystem functions such as species richness, nitrogen fixation, and erosion control. Knowledge about the spatial distribution of plant functional groups provides valuable information for grassland management. This study described and mapped the distribution of grass, herb, and legume coverage of the subalpine grassland in the high-mountain Kazbegi region, Greater Caucasus, Georgia. To test the applicability of new sensors, we compared the predictive power of simulated hyperspectral canopy reflectance, simulated multispectral reflectance, simulated vegetation indices, and topographic variables for modeling plant functional groups. The tested grassland showed characteristic differences in species richness; in grass, herb, and legume coverage; and in connected structural properties such as yield. Grass (Hordeum brevisubulatum was dominant in biomass-rich hay meadows. Herb-rich grassland featured the highest species richness and evenness, whereas legume-rich grassland was accompanied by a high coverage of open soil and showed dominance of a single species, Astragalus captiosus. The best model fits were achieved with a combination of reflectance, vegetation indices, and topographic variables as predictors. Random forest models for grass, herb, and legume coverage explained 36%, 25%, and 37% of the respective variance, and their root mean square errors varied between 12–15%. Hyperspectral and multispectral reflectance as predictors resulted in similar models. Because multispectral data are more easily available and often have a higher spatial resolution, we suggest using multispectral parameters enhanced by vegetation indices and topographic parameters for modeling grass, herb, and legume coverage. However, overall model fits were merely moderate, and further testing, including stronger gradients and the addition of

  5. Biodiversity of Soil Microbial Communities Following Woody Plant Invasion of Grassland: An Assessment Using Molecular Methods

    Science.gov (United States)

    Kantola, I. B.; Gentry, T. J.; Filley, T. R.; Boutton, T. W.

    2012-12-01

    Woody plants have encroached into grasslands, savannas, and other grass-dominated ecosystems throughout the world during the last century. This dramatic vegetation change is likely driven by livestock grazing, altered fire frequencies, elevated atmospheric CO2 concentrations, and/or changes in atmospheric deposition patterns. Woody invasion often results in significant changes in ecosystem function, including alterations in above- and belowground primary productivity, soil C, N, and P storage and turnover, and the size and activity of the soil microbial biomass pool. The purpose of this study was to examine the relationships and interactions between plant communities and soil microbial communities in the Rio Grande Plains region of southern Texas where grasslands have been largely replaced by woodlands. Research was conducted along a successional chronosequence representing the stages of woody plant encroachment from open grassland to closed-canopy woodland. To characterize soil microbial community composition, soil samples (0-7.5 cm) were collected in remnant grasslands (representing time 0) and near the centers of woody plant clusters, groves, and drainage woodlands ranging in age from 10 to 130 yrs. Ages of woody plant stands were determined by dendrochronology. Community DNA was extracted from each soil sample with a MoBio PowerMax Soil DNA isolation kit. The DNA concentrations were quantified on a NanoDrop ND-1000 spectrophotometer and diluted to a standard concentration. Pyrosequencing was performed by the Research and Testing Laboratory (Lubbock, TX) according to Roche 454 Titanium chemistry protocols. Samples were amplified with primers 27F and 519R for bacteria, and primers ITS1F and ITS4 for fungi. Sequences were aligned using BioEdit and the RDP Pipeline and analyzed in MOTHUR. Non-metric multidimensional scaling of the operational taxonomic units identified by pyrosequencing revealed that both bacterial and fungal community composition were

  6. New phytotoxic diterpenoids from Vellozia gigantea (Velloziaceae), an endemic neotropical plant living in the endangered Brazilian biome Rupestrian grasslands

    Science.gov (United States)

    Vellozia gigantea is a rare, ancient and endemic neotropical plant present in the Brazilian Rupestrian grasslands. The dichloromethane extract of V. gigantea adventitious roots was phytotoxic against Lactuca sativa, Agrostis stolonifera and Lemna paucicostata, and showed larvicidal activity against ...

  7. Impacts of atmospheric pollution on the plant communities of British acid grasslands

    Energy Technology Data Exchange (ETDEWEB)

    Payne, Richard J., E-mail: r.payne@mmu.ac.uk [School of Science and the Environment, Manchester Metropolitan University, Chester St., Manchester M1 5GD (United Kingdom); Geography, School of Environment and Development, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Stevens, Carly J. [Faculty of Science, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ (United Kingdom); Dise, Nancy B. [School of Science and the Environment, Manchester Metropolitan University, Chester St., Manchester M1 5GD (United Kingdom); Gowing, David J. [Faculty of Science, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Pilkington, Michael G.; Phoenix, Gareth K. [Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, Sheffield S10 2TN (United Kingdom); Emmett, Bridget A. [Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW (United Kingdom); Ashmore, Michael R. [Environment Department, University of York, Heslington, York YO10 5DD (United Kingdom)

    2011-10-15

    Air pollutants are recognised as important agents of ecosystem change but few studies consider the effects of multiple pollutants and their interactions. Here we use ordination, constrained cluster analysis and indicator value analyses to identify potential environmental controls on species composition, ecological groupings and indicator species in a gradient study of UK acid grasslands. The community composition of these grasslands is related to climate, grazing, ozone exposure and nitrogen deposition, with evidence for an interaction between the ecological impacts of base cation and nitrogen deposition. Ozone is a key agent in species compositional change but is not associated with a reduction in species richness or diversity indices, showing the subtly different drivers on these two aspects of ecosystem degradation. Our results demonstrate the effects of multiple interacting pollutants, which may collectively have a greater impact than any individual agent. - Highlights: > Ozone exposure, N and base cation deposition modify UK acid grassland composition. > Ozone influences community composition without reducing species richness. > Nitrogen and base cation deposition have interacting impacts. > Distinct species responses to pollutants suggest potential for bioindication. - Ozone exposure and nitrogen deposition have distinct but additive impacts on the plant communities of British acid grasslands.

  8. Impacts of atmospheric pollution on the plant communities of British acid grasslands

    International Nuclear Information System (INIS)

    Payne, Richard J.; Stevens, Carly J.; Dise, Nancy B.; Gowing, David J.; Pilkington, Michael G.; Phoenix, Gareth K.; Emmett, Bridget A.; Ashmore, Michael R.

    2011-01-01

    Air pollutants are recognised as important agents of ecosystem change but few studies consider the effects of multiple pollutants and their interactions. Here we use ordination, constrained cluster analysis and indicator value analyses to identify potential environmental controls on species composition, ecological groupings and indicator species in a gradient study of UK acid grasslands. The community composition of these grasslands is related to climate, grazing, ozone exposure and nitrogen deposition, with evidence for an interaction between the ecological impacts of base cation and nitrogen deposition. Ozone is a key agent in species compositional change but is not associated with a reduction in species richness or diversity indices, showing the subtly different drivers on these two aspects of ecosystem degradation. Our results demonstrate the effects of multiple interacting pollutants, which may collectively have a greater impact than any individual agent. - Highlights: → Ozone exposure, N and base cation deposition modify UK acid grassland composition. → Ozone influences community composition without reducing species richness. → Nitrogen and base cation deposition have interacting impacts. → Distinct species responses to pollutants suggest potential for bioindication. - Ozone exposure and nitrogen deposition have distinct but additive impacts on the plant communities of British acid grasslands.

  9. Nitrogen transfer from forage legumes to nine neighbouring plants in a multi-species grassland

    DEFF Research Database (Denmark)

    Pirhofer-Walzl, Karin; Rasmussen, Jim; Jensen, Henning Høgh

    2012-01-01

    Legumes play a crucial role in nitrogen supply to grass-legume mixtures for ruminant fodder. To quantify N transfer from legumes to neighbouring plants in multi-species grasslands we established a grass-legume-herb mixture on a loamy-sandy site in Denmark. White clover (Trifolium repens L.), red...... amounts of N from legumes than dicotyledonous plants which generally have taproots. Slurry application mainly increased N transfer from legumes to grasses. During the growing season the three legumes transferred approximately 40 kg N ha-1 to neighbouring plants. Below-ground N transfer from legumes...

  10. No evidence of complementary water use along a plant species richness gradient in temperate experimental grasslands.

    Directory of Open Access Journals (Sweden)

    Dörte Bachmann

    Full Text Available Niche complementarity in resource use has been proposed as a key mechanism to explain the positive effects of increasing plant species richness on ecosystem processes, in particular on primary productivity. Since hardly any information is available for niche complementarity in water use, we tested the effects of plant diversity on spatial and temporal complementarity in water uptake in experimental grasslands by using stable water isotopes. We hypothesized that water uptake from deeper soil depths increases in more diverse compared to low diverse plant species mixtures. We labeled soil water in 8 cm (with 18O and 28 cm depth (with ²H three times during the 2011 growing season in 40 temperate grassland communities of varying species richness (2, 4, 8 and 16 species and functional group number and composition (legumes, grasses, tall herbs, small herbs. Stable isotope analyses of xylem and soil water allowed identifying the preferential depth of water uptake. Higher enrichment in 18O of xylem water than in ²H suggested that the main water uptake was in the upper soil layer. Furthermore, our results revealed no differences in root water uptake among communities with different species richness, different number of functional groups or with time. Thus, our results do not support the hypothesis of increased complementarity in water use in more diverse than in less diverse communities of temperate grassland species.

  11. The Effect of Re-Planting Trees on Soil Microbial Communities in a Wildfire-Induced Subalpine Grassland

    Directory of Open Access Journals (Sweden)

    Ed-Haun Chang

    2017-10-01

    Full Text Available Wildfire often causes tremendous changes in ecosystems, particularly in subalpine and alpine areas, which are vulnerable due to severe climate conditions such as cold temperature and strong wind. This study aimed to clarify the effect of tree re-planting on ecosystem services such as the soil microbial community after several decades. We compared the re-planted forest and grassland with the mature forest as a reference in terms of soil microbial biomass C and N (Cmic and Nmic, enzyme activities, phospholipid fatty acids (PLFA composition, and denaturing gradient gel electrophoresis (DGGE. The Cmic and Nmic did not differ among the grassland, re-planted forest and mature forest soil; however, ratios of Cmic/Corg and Nmic/Ntot decreased from the grassland to re-planted forest and mature forest soil. The total PLFAs and those attributed to bacteria and Gram-positive and Gram-negative bacteria did not differ between the re-planted forest and grassland soil. Principle component analysis of the PLFA content separated the grassland from re-planted forest and mature forest soil. Similarly, DGGE analysis revealed changes in both bacterial and fungal community structures with changes in vegetation. Our results suggest that the microbial community structure changes with the re-planting of trees after a fire event in this subalpine area. Recovery of the soil microbial community to the original state in a fire-damaged site in a subalpine area may require decades, even under a re-planted forest.

  12. Plant species' origin predicts dominance and response to nutrient enrichment and herbivores in global grasslands

    Science.gov (United States)

    Seabloom, Eric W.; Borer, Elizabeth T.; Buckley, Yvonne M.; Cleland, Elsa E.; Davies, Kendi F.; Firn, Jennifer; Harpole, W. Stanley; Hautier, Yann; Lind, Eric M.; MacDougall, Andrew S.; Orrock, John L.; Prober, Suzanne M.; Adler, Peter B.; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori A.; Blumenthal, Dana M.; Brown, Cynthia S.; Brudvig, Lars A.; Cadotte, Marc; Chu, Chengjin; Cottingham, Kathryn L.; Crawley, Michael J.; Damschen, Ellen I.; Dantonio, Carla M.; DeCrappeo, Nicole M.; Du, Guozhen; Fay, Philip A.; Frater, Paul; Gruner, Daniel S.; Hagenah, Nicole; Hector, Andy; Hillebrand, Helmut; Hofmockel, Kirsten S.; Humphries, Hope C.; Jin, Virginia L.; Kay, Adam; Kirkman, Kevin P.; Klein, Julia A.; Knops, Johannes M. H.; La Pierre, Kimberly J.; Ladwig, Laura; Lambrinos, John G.; Li, Qi; Li, Wei; Marushia, Robin; McCulley, Rebecca L.; Melbourne, Brett A.; Mitchell, Charles E.; Moore, Joslin L.; Morgan, John; Mortensen, Brent; O'Halloran, Lydia R.; Pyke, David A.; Risch, Anita C.; Sankaran, Mahesh; Schuetz, Martin; Simonsen, Anna; Smith, Melinda D.; Stevens, Carly J.; Sullivan, Lauren; Wolkovich, Elizabeth; Wragg, Peter D.; Wright, Justin; Yang, Louie

    2015-01-01

    Exotic species dominate many communities; however the functional significance of species' biogeographic origin remains highly contentious. This debate is fuelled in part by the lack of globally replicated, systematic data assessing the relationship between species provenance, function and response to perturbations. We examined the abundance of native and exotic plant species at 64 grasslands in 13 countries, and at a subset of the sites we experimentally tested native and exotic species responses to two fundamental drivers of invasion, mineral nutrient supplies and vertebrate herbivory. Exotic species are six times more likely to dominate communities than native species. Furthermore, while experimental nutrient addition increases the cover and richness of exotic species, nutrients decrease native diversity and cover. Native and exotic species also differ in their response to vertebrate consumer exclusion. These results suggest that species origin has functional significance, and that eutrophication will lead to increased exotic dominance in grasslands. PMID:26173623

  13. Changes in grassland management and plant diversity in a marginal region of the Carpathian Mts. in 1999-2015.

    Science.gov (United States)

    Halada, Ľuboš; David, Stanislav; Hreško, Juraj; Klimantová, Alexandra; Bača, Andrej; Rusňák, Tomáš; Buraľ, Miroslav; Vadel, Ľuboš

    2017-12-31

    The political change from socialism to democracy in countries of Central and Eastern Europe at the end of the 20th century induced broad changes in agriculture mostly due to land ownership changes and strong reduction of subsidies to agriculture. This resulted in agricultural decline, including grassland abandonment, which influenced grassland biodiversity and conservation. Between 1999 and 2015 we studied the grasslands in the area depopulated in the early 1980's in the Poloniny National Park (NE Slovakia, Carpathian Mts.). The aim of the study was to examine influence of environmental factors and grassland management driven by the Common Agricultural Policy (CAP) to plant community structure and taxonomical diversity. We identified altitude and soil properties as the main environmental factors: altitude determines climate gradient and probably also management intensity gradient and soil properties express soil fertility via A-horizon depth. We identified remarkable increase of proportion of managed grasslands from only 8% in 1999 to 40% in 2012-2015; other 7% of sampled grasslands were recently restored and prepared for future management. The average species richness in grasslands managed in 2012-2015 increased from 47.5 species per record in 1999 to 54.2 species in 2012-2015, the increase was found statistically significant. In 2012-2015, we observed statistically significant difference in the average species richness between managed (54.2) and abandoned grasslands (46.3). The agricultural subsidies of the CAP drive the grassland management in the study area. Therefore, we conclude that CAP enabled grassland biodiversity maintenance in significant part of the Poloniny National Park following start of its application in 2004 and above provided figures can be considered as indicators of the CAP effectiveness in our study area. However, the conservation of mountain meadows remains a challenge because of their poor accessibility. Copyright © 2017 Elsevier B.V. All

  14. Soil Seed Bank and Plant Community Development in Passive Restoration of Degraded Sandy Grasslands

    Directory of Open Access Journals (Sweden)

    Renhui Miao

    2016-06-01

    Full Text Available To evaluate the efficacy of passive restoration on soil seed bank and vegetation recovery, we measured the species composition and density of the soil seed bank, as well as the species composition, density, coverage, and height of the extant vegetation in sites passively restored for 0, 4, 7, and 12 years (S0, S4, S7, and S12 in a degraded grassland in desert land. Compared with S0, three more species in the soil seed bank at depths of 0–30 cm and one more plant species in the community was detected in S12. Seed density within the topsoil (0–5 cm was five times higher in S12 than that in S0. Plant densities in S7 and S12 were triple and quadruple than that in S0. Plant coverage was increased by 1.5 times (S4, double (S7, and triple (S12 compared with S0. Sørensen’s index of similarity in species composition between the soil seed bank and the plant community were high (0.43–0.63, but it was lower in short-term restoration sites (S4 and S7 than that in no and long-term restoration sites (S0 and S12. The soil seed bank recovered more slowly than the plant community under passive restoration. Passive restoration is a useful method to recover the soil seed bank and vegetation in degraded grasslands.

  15. Responses of Ammonia-Oxidising Bacterial Communities to Nitrogen, Lime, and Plant Species in Upland Grassland Soil

    International Nuclear Information System (INIS)

    Rooney, D.C.; Kennedy, N.M.; Clipson, N.J.W.; Rooney, D.C.; Kennedy, N.M.; Gleeson, D.B.

    2010-01-01

    Agricultural improvement of semi natural grasslands has been shown to result in changes to plant and microbial diversity, with consequences for ecosystem functioning. A microcosm approach was used to elucidate the effects of two key components of agricultural improvement (nitrogen addition and liming) on ammonia-oxidising bacterial (AOB) communities in an upland grassland soil. Plant species characteristic of unimproved and improved pastures (A. capillaries and L. perenne) were planted in microcosms, and lime, nitrogen (NH 4 NO 3 ), or lime plus nitrogen added. The AOB community was profiled using terminal restriction fragment length polymorphism (TRFLP) of the amoA gene. AOB community structure was largely altered by NH 4 NO 3 addition, rather than liming, although interactions between nitrogen addition and plant species were also evident. Results indicate that nitrogen addition drives shifts in the structure of key microbial communities in upland grassland soils, and that plant species may play a significant role in determining AOB community structure

  16. How Fencing Affects the Soil Quality and Plant Biomass in the Grassland of the Loess Plateau.

    Science.gov (United States)

    Zeng, Quanchao; Liu, Yang; Xiao, Li; Huang, Yimei

    2017-09-25

    Overgrazing is a severe problem in several regions in Northwestern China and has caused serious land degradation. Secondary natural succession plays an important role in the accumulation of soil carbon and nitrogen contents. Estimating the effects of grazing exclusion on soil quality and plant diversity will improve our understanding of the succession process after overgrazing and promote judicious management of degraded pastures. This experiment was designed to measure soil properties and plant diversity following an age chronosequence of grasslands (ages ranged from one year, 12 years, 20 years, and 30 years) in Northwestern China. The results showed that continuous fencing resulted in a considerable increase in plant coverage, plant biomass (above- and below-ground biomass), and plant diversity, which can directly or indirectly improve the accumulation of soil organic carbon and total nitrogen content. The plant coverage and the above- and below-ground biomass linearly increased along the succession time, whereas soil organic C and N contents showed a significant decline in the first 12 years and, subsequently, a significant increase. The increased plant biomass caused an increase in soil organic carbon and soil total nitrogen. These results suggested that soil restoration and plant cover were an incongruous process. Generally, soil restoration is a slow process and falls behind vegetation recovery after grazing exclusion. Although the accumulation of soil C and N stocks needed a long term, vegetation restoration was a considerable option for the degraded grassland due to the significant increase of plant biomass, diversity, and soil C and N stocks. Therefore, fencing with natural succession should be considered in the design of future degraded pastures.

  17. Floristic and vegetation structure of a grassland plant community on shallow basalt in southern Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo Fett Pinto

    2013-03-01

    Full Text Available Few studies have adequately described the floristic and structural features of natural grasslands associated with shallow basalt soils in southern Brazil. This study was carried out on natural grazing land used for livestock production in the municipality of Santana do Livramento, in the Campanha region of the state of Rio Grande do Sul, Brazil. The aim of the study was to describe the floristic and structural diversity of the area. The floristic list obtained comprises 229 plant taxa from 40 botanical families, with a predominance of the families Poaceae (62, Asteraceae (28, Fabaceae (16 and Cyperaceae (12. The estimated diversity and evenness in the community were 3.00 and 0.874, respectively. Bare soil and rock outcrops accounted for 19.3% of the area, resulting in limited forage availability. Multivariate analysis revealed two well-defined groups among the sampling units. One group showed a high degree of internal aggregation, associated with deep soils, and was characterized by the presence of tussocks, whereas the other was less aggregate and was characterized by prostrate species growing on shallow soil. Ordination analysis indicated a gradient of moisture and of soil depth in the study area, resulting in different vegetation patterns. These patterns were analogous to the vegetation physiognomies described for Uruguayan grasslands. Overall, the grassland community studied is similar to others found throughout southern Brazil, although it harbors more winter forage species. In addition, the rare grass Paspalum indecorum Mez is locally dominant in some patches, behaving similarly to P. notatum Fl., a widespread grass that dominates extensive grassland areas in southern Brazil.

  18. Changes in plant species richness induce functional shifts in soil nematode communities in experimental grassland.

    Directory of Open Access Journals (Sweden)

    Nico Eisenhauer

    Full Text Available Changes in plant diversity may induce distinct changes in soil food web structure and accompanying soil feedbacks to plants. However, knowledge of the long-term consequences of plant community simplification for soil animal food webs and functioning is scarce. Nematodes, the most abundant and diverse soil Metazoa, represent the complexity of soil food webs as they comprise all major trophic groups and allow calculation of a number of functional indices.We studied the functional composition of nematode communities three and five years after establishment of a grassland plant diversity experiment (Jena Experiment. In response to plant community simplification common nematode species disappeared and pronounced functional shifts in community structure occurred. The relevance of the fungal energy channel was higher in spring 2007 than in autumn 2005, particularly in species-rich plant assemblages. This resulted in a significant positive relationship between plant species richness and the ratio of fungal-to-bacterial feeders. Moreover, the density of predators increased significantly with plant diversity after five years, pointing to increased soil food web complexity in species-rich plant assemblages. Remarkably, in complex plant communities the nematode community shifted in favour of microbivores and predators, thereby reducing the relative abundance of plant feeders after five years.The results suggest that species-poor plant assemblages may suffer from nematode communities detrimental to plants, whereas species-rich plant assemblages support a higher proportion of microbivorous nematodes stimulating nutrient cycling and hence plant performance; i.e. effects of nematodes on plants may switch from negative to positive. Overall, food web complexity is likely to decrease in response to plant community simplification and results of this study suggest that this results mainly from the loss of common species which likely alter plant-nematode interactions.

  19. Herbivory and eutrophication mediate grassland plant nutrient responses across a global climatic gradient

    Science.gov (United States)

    Anderson, T. Michael; Griffith, Daniel M.; Grace, James B.; Lind, Eric M.; Adler, Peter B.; Biederman, Lori A.; Blumenthal, Dana M.; Daleo, Pedro; Firn, Jennifer; Hagenah, Nicole; Harpole, W. Stanley; MacDougall, Andrew S.; McCulley, Rebecca L.; Prober, Suzanne M.; Risch, Anita C.; Sankaran, Mahesh; Schütz, Martin; Seabloom, Eric W.; Stevens, Carly J.; Sullivan, Lauren; Wragg, Peter; Borer, Elizabeth T.

    2018-01-01

    Plant stoichiometry, the relative concentration of elements, is a key regulator of ecosystem functioning and is also being altered by human activities. In this paper we sought to understand the global drivers of plant stoichiometry and compare the relative contribution of climatic vs. anthropogenic effects. We addressed this goal by measuring plant elemental (C, N, P and K) responses to eutrophication and vertebrate herbivore exclusion at eighteen sites on six continents. Across sites, climate and atmospheric N deposition emerged as strong predictors of plot‐level tissue nutrients, mediated by biomass and plant chemistry. Within sites, fertilization increased total plant nutrient pools, but results were contingent on soil fertility and the proportion of grass biomass relative to other functional types. Total plant nutrient pools diverged strongly in response to herbivore exclusion when fertilized; responses were largest in ungrazed plots at low rainfall, whereas herbivore grazing dampened the plant community nutrient responses to fertilization. Our study highlights (1) the importance of climate in determining plant nutrient concentrations mediated through effects on plant biomass, (2) that eutrophication affects grassland nutrient pools via both soil and atmospheric pathways and (3) that interactions among soils, herbivores and eutrophication drive plant nutrient responses at small scales, especially at water‐limited sites.

  20. Diversity of arbuscular mycorrhizal fungi in grassland spontaneously developed on area polluted by a fertilizer plant

    International Nuclear Information System (INIS)

    Renker, C.; Blanke, V.; Buscot, F.

    2005-01-01

    Mycorrhizal colonization and diversity of arbuscular mycorrhizal fungi (AMF) were analyzed in a calcareous grassland with residual phosphate contamination 10 years after the closure of a pollutant fertilizer plant in Thuringia (Germany). AMF were detected in 21 of 22 plant species analyzed. Mean mycorrhization levels reached up to 74.5% root length colonized. AMF diversity was analyzed based on 104 sequences of the internal transcribed spacer (ITS) of the ribosomal DNA. Phylogenetic analyses revealed a total of 6 species all belonging to the genus Glomus. There was no overlap between species detected as active mycorrhizas on roots (2 taxa) or as spores (4 taxa). Compared to the regional context, the diversity of AMF at our field site was reduced, which may reflect a residual disturbance effect. However, none of the detected species was exclusive to the polluted site as they are commonly found in the region. - Almost all plant species were mycorrhizal

  1. Controls upon microbial accessibility to soil organic matter following woody plant encroachment into grasslands

    Science.gov (United States)

    Creamer, C. A.; Boutton, T. W.; Filley, T. R.

    2009-12-01

    Woody plant encroachment (WPE) into savannas and grasslands is a global phenomenon that alters soil organic matter (SOM) dynamics through changes in litter quality and quantity, soil structure, microbial ecology, and soil hydrology. To elucidate the controls upon microbial accessibility to SOM, bulk soils from a chronosequence of progressive WPE into native grasslands at the Texas A&M Agricultural Experimental Station La Copita Research Area were incubated for one year. The quantity and stable carbon isotope composition of respired CO2, plant biopolymer chemistry in SOM, and microbial community structure were tracked. Respiration rates declined steadily over the course of the experiment with 15-25% of the total CO2 respired released in the first month of incubation. Between 8 and 18% of the total carbon was mineralized to CO2 throughout the incubation. After day 84 a significantly (p evidence of enhanced carbon stabilization in these respiration experiments. In fact, a greater proportion of total carbon was lost from the soil of mature woody stands than from young stands, suggesting carbon accumulation observed with WPE may be due to greater input rates or microbial dynamics not captured in the laboratory incubation. A cluster approximately 34 years in age represents a transition point in WPE where respiration dynamics become distinct between grassland and wooded elements. By day 84 of the incubation CO2 respired from all soils was depleted with respect to bulk SOM (1.5 to 5‰) and this pattern remained for the rest of the incubation. As the depletion of CO2 relative to bulk SOM was observed in grassland and cluster soils, we hypothesized the depleted signature resulted from the utilization of depleted biopolymers, specifically lignin, cutin and suberin, as hypothesized by others. Quantitative and isotopic comparisons of these monomers prior to and following the incubation will determine if selective compound utilization is a reason for this depletion. The results

  2. Long-term reactions of plants and macroinvertebrates to extreme floods in floodplain grasslands.

    Science.gov (United States)

    Ilg, Christiane; Dziock, Frank; Foeckler, Francis; Follner, Klaus; Gerisch, Michael; Glaeser, Judith; Rink, Anke; Schanowski, Arno; Scholz, Mathias; Deichner, Oskar; Henle, Klaus

    2008-09-01

    Extreme summertime flood events are expected to become more frequent in European rivers due to climate change. In temperate areas, where winter floods are common, extreme floods occurring in summer, a period of high physiological activity, may seriously impact floodplain ecosystems. Here we report on the effects of the 2002 extreme summer flood on flora and fauna of the riverine grasslands of the Middle Elbe (Germany), comparing pre- and post-flooding data collected by identical methods. Plants, mollusks, and carabid beetles differed considerably in their response in terms of abundance and diversity. Plants and mollusks, displaying morphological and behavioral adaptations to flooding, showed higher survival rates than the carabid beetles, the adaptation strategies of which were mainly linked to life history. Our results illustrate the complexity of responses of floodplain organisms to extreme flood events. They demonstrate that the efficiency of resistance and resilience strategies is widely dependent on the mode of adaptation.

  3. [Soil catalase activity of main plant communities in Leymus chinensis grassland in northeast China].

    Science.gov (United States)

    Lu, Ping; Guo, Jixun; Zhu, Li

    2002-06-01

    The seasonal dynamics of soil catalase activity of three different plants communities in Leymus chinensis grassland in northeast China were in a parabolas shape. The seasonal variation of Chloris virgata community was greater than those of Leymus chinensis community and Puccinellia tenuiflora community, and "seed effect" might be the main reason. The correlation between the activity of soil catalase in different soil layers and environmental factors were analyzed. The results showed that the activity of soil catalase was decreased gradually with depth of soil layer. The activity of soil catalase was closely correlated with rainfall and air temperature, and it was affected by soil temperature, soil moisture, and their interactions. The correlation between the activity and aboveground vegetation was very significant, and the growing condition of plant communities could be reflected by the activity of soil catalase.

  4. Incorporating biodiversity into rangeland health: Plant species richness and diversity in great plains grasslands

    Science.gov (United States)

    Symstad, Amy J.; Jonas, Jayne L.

    2011-01-01

    Indicators of rangeland health generally do not include a measure of biodiversity. Increasing attention to maintaining biodiversity in rangelands suggests that this omission should be reconsidered, and plant species richness and diversity are two metrics that may be useful and appropriate. Ideally, their response to a variety of anthropogenic and natural drivers in the ecosystem of interest would be clearly understood, thereby providing a means to diagnose the cause of decline in an ecosystem. Conceptual ecological models based on ecological principles and hypotheses provide a framework for this understanding, but these models must be supported by empirical evidence if they are to be used for decision making. To that end, we synthesize results from published studies regarding the responses of plant species richness and diversity to drivers that are of management concern in Great Plains grasslands, one of North America's most imperiled ecosystems. In the published literature, moderate grazing generally has a positive effect on these metrics in tallgrass prairie and a neutral to negative effect in shortgrass prairie. The largest published effects on richness and diversity were caused by moderate grazing in tallgrass prairies and nitrogen fertilization in shortgrass prairies. Although weather is often cited as the reason for considerable annual fluctuations in richness and diversity, little information about the responses of these metrics to weather is available. Responses of the two metrics often diverged, reflecting differences in their sensitivity to different types of changes in the plant community. Although sufficient information has not yet been published for these metrics to meet all the criteria of a good indicator in Great Plains Grasslands, augmenting current methods of evaluating rangeland health with a measure of plant species richness would reduce these shortcomings and provide information critical to managing for biodiversity.

  5. Relationship between plant biodiversity and heavy metal bioavailability in grasslands overlying an abandoned mine.

    Science.gov (United States)

    Hernández, A J; Pastor, J

    2008-04-01

    Abandoned metal mines in the Sierra de Guadarrama, Madrid, Spain, are often located in areas of high ecological value. This is true of an abandoned barium mine situated in the heart of a bird sanctuary. Today the area sustains grasslands, interspersed with oakwood formations of Quercus ilex and heywood scrub (Retama sphaerocarpa L.), used by cattle, sheep and wild animals. Our study was designed to establish a relationship between the plant biodiversity of these grasslands and the bioavailability of heavy metals in the topsoil layer of this abandoned mine. We conducted soil chemical analyses and performed a greenhouse evaluation of the effects of different soil heavy metal concentrations on biodiversity. The greenhouse bioassays were run for 6 months using soil samples obtained from the mine polluted with heavy metals (Cu, Zn, Pb and Cd) and from a control pasture. Soil heavy metal and Na concentrations, along with the pH, had intense negative effects on plant biodiversity, as determined through changes in the Shannon index and species richness. Numbers of grasses, legumes, and composites were reduced, whilst other species (including ruderals) were affected to a lesser extent. Zinc had the greatest effect on biodiversity, followed by Cd and Cu. When we compared the sensitivity of the biodiversity indicators to the different metal content variables, pseudototal metal concentrations determined by X-ray fluorescence (XRF) were the most sensitive, followed by available and soluble metal contents. Worse correlations between biodiversity variables and metal variables were shown by pseudototal contents obtained by plasma emission spectroscopy (ICP-OES). Our results highlight the importance of using as many different indicators as possible to reliably assess the response shown by plants to heavy metal soil pollution.

  6. Root-induced decomposer growth and plant N uptake are not positively associated among a set of grassland plants

    DEFF Research Database (Denmark)

    Saj, S.; Mikola, J.; Ekelund, Flemming

    2008-01-01

    It is known that plant species can induce development of different soil decomposer communities and that they differ in their influence on organic matter decomposition and N mineralization in soil. However, no study has so far assessed whether these two observations are related to each other. Base...... that plant traits such as competitive ability for soil mineral N were more important for plant uptake of litter-N than those that directly affected the growth of soil decomposers.......It is known that plant species can induce development of different soil decomposer communities and that they differ in their influence on organic matter decomposition and N mineralization in soil. However, no study has so far assessed whether these two observations are related to each other. Based...... on the hypothesis that root-induced growth of soil decomposers leads to accelerated decomposition of SOM and increased plant N availability in soil, we predicted that (1) among a set of grassland plants the abundance of soil decomposers in the plant rhizosphere is positively associated with plant N uptake from soil...

  7. Urban Power Line Corridors as Novel Habitats for Grassland and Alien Plant Species in South-Western Finland.

    Directory of Open Access Journals (Sweden)

    Jussi Lampinen

    Full Text Available Regularly managed electric power line corridors may provide habitats for both early-successional grassland plant species and disturbance-dependent alien plant species. These habitats are especially important in urban areas, where they can help conserve native grassland species and communities in urban greenspace. However, they can also provide further footholds for potentially invasive alien species that already characterize urban areas. In order to implement power line corridors into urban conservation, it is important to understand which environmental conditions in the corridors favor grassland species and which alien species. Likewise it is important to know whether similar environmental factors in the corridors control the species composition of the two groups. We conducted a vegetation study in a 43 kilometer long urban power line corridor network in south-western Finland, and used generalized linear models and distance-based redundancy analysis to determine which environmental factors best predict the occurrence and composition of grassland and alien plant species in the corridors. The results imply that old corridors on dry soils and steep slopes characterized by a history as open areas and pastures are especially suitable for grassland species. Corridors suitable for alien species, in turn, are characterized by productive soils and abundant light and are surrounded by a dense urban fabric. Factors controlling species composition in the two groups are somewhat correlated, with the most important factors including light abundance, soil moisture, soil calcium concentration and soil productivity. The results have implications for grassland conservation and invasive alien species control in urban areas.

  8. Belowground Carbon Allocation and Plant-Microbial Interactions Drive Resistance and Resilience of Mountain Grassland Communities to Drought

    Science.gov (United States)

    Karlowsky, S.; Augusti, A.; Ingrisch, J.; Hasibeder, R.; Lavorel, S.; Bahn, M.; Gleixner, G.

    2016-12-01

    Belowground carbon allocation (BCA) and plant-microbial interactions are crucial for the functioning of terrestrial ecosystems. Recent research suggests that extreme events can have severe effects on these processes but it is unknown how land use intensity potentially modifies their responses. We studied the resistance and resilience of mountain grassland communities to prolonged drought and investigated the role of plant C allocation and soil microbial communities in mediating drought resistance and immediate recovery. In a common garden experiment we exposed monoliths from an abandoned grassland and a hay meadow to an early summer drought. Two independent 13C pulse labeling experiments were conducted, the first during peak drought and the second during the recovery phase. The 13C incorporation was analyzed in above- and belowground plant parts and in phospho- and neutral lipid fatty acids of soil microorganisms. In addition, a 15N label was added at the rewetting to determine plant N uptake. We found that C uptake, BCA and C transfer to soil microorganisms were less strongly reduced by drought in the abandoned grassland than in the meadow. Moreover, drought induced an increase of arbuscular mycorrhiza fungi (AMF) marker in the abandoned grassland. Nevertheless, C uptake and related parameters were quickly recovered and N uptake increased in the meadow during recovery. Unexpectedly, AMF and their C uptake were generally reduced during recovery, while bacteria increased and quickly recovered C uptake, particularly in the meadow. Our results showed a negative relation between high resistance and fast recovery. The more resistant abandoned grassland plant communities seemed to invest more C below ground and into interactions with AMF during drought, likely to access water through their hyphal network. Conversely, meadow communities invested more C from recent photosynthesis into bacterial communities during recovery, obviously to gain more nutrients for regrowth

  9. Elevated CO2 and water addition enhance nitrogen turnover in grassland plants with implications for temporal stability.

    Science.gov (United States)

    Dijkstra, Feike A; Carrillo, Yolima; Blumenthal, Dana M; Mueller, Kevin E; LeCain, Dan R; Morgan, Jack A; Zelikova, Tamara J; Williams, David G; Follett, Ronald F; Pendall, Elise

    2018-05-01

    Temporal variation in soil nitrogen (N) availability affects growth of grassland communities that differ in their use and reuse of N. In a 7-year-long climate change experiment in a semi-arid grassland, the temporal stability of plant biomass production varied with plant N turnover (reliance on externally acquired N relative to internally recycled N). Species with high N turnover were less stable in time compared to species with low N turnover. In contrast, N turnover at the community level was positively associated with asynchrony in biomass production, which in turn increased community temporal stability. Elevated CO 2 and summer irrigation, but not warming, enhanced community N turnover and stability, possibly because treatments promoted greater abundance of species with high N turnover. Our study highlights the importance of plant N turnover for determining the temporal stability of individual species and plant communities affected by climate change. © 2018 John Wiley & Sons Ltd/CNRS.

  10. Grazing damage to plants and gastropod and grasshopper densities in a CO 2-enrichment experiment on calcareous grassland

    Science.gov (United States)

    Ledergerber, Stephan; Thommen, G. Heinrich; Baur, Bruno

    Plant-herbivore interactions may change as atmospheric CO 2 concentrations continue to rise. We examined the effects of elevated atmospheric CO 2 and CO 2-exposure chambers on the grazing damage to plants, and on the abundances of potential herbivores (terrestrial gastropods and grasshoppers) in a calcareous grassland in the Jura mountains of Switzerland (village of Nenzlingen). Individuals of most plant species examined showed slight grazing damage. However, plots with CO 2 enrichment and plots with ambient atmosphere did not differ in the extent of grazing damage. Similarly, plots with CO 2 enrichment and plots with ambient atmosphere did not differ in either gastropod or grasshopper density. Experimental plots with and without chambers did not differ in the number of gastropods. However, the densities of gastropods and grasshoppers and extent of grazing damage to plants were generally lower in the experimental area than in the grassland outside the experimental field.

  11. Rapid top-down regulation of plant C:N:P stoichiometry by grasshoppers in an Inner Mongolia grassland ecosystem.

    Science.gov (United States)

    Zhang, Guangming; Han, Xingguo; Elser, James J

    2011-05-01

    Understanding how food web interactions alter the processing of limiting nutrient elements is an important goal of ecosystem ecology. An experiment manipulating densities of the grasshopper Oedaleus asiaticus was performed to assess top-down effects of grasshoppers on C:N:P stoichiometry of plants and soil in a grassland ecosystem in Inner Mongolia (China). With increased grasshopper feeding, plant biomass declined fourfold, litter abundance increased 30%, and the plant community became dominated by non-host plant taxa. Plant stoichiometric response depended on whether or not the plant was a grasshopper host food species: C:N and C:P ratios increased with increasing grasshopper density (GD) for host plants but decreased in non-host plants. These data suggest either a direct transfer of grasshopper-recycled nutrients from host to non-host plants or a release of non-host plants from nutrient competition with heavily grazed host plants. Litterfall C:N and C:P decreased across moderate levels of grasshopper density but no effects on C:N:P stoichiometry in the surface soil were observed, possibly due to the short experimental period. Our observations of divergent C:N:P stoichiometric response among plant species highlight the important role of grasshopper herbivory in regulating plant community structure and nutrient cycling in grassland ecosystems.

  12. Subsurface earthworm casts can be important soil microsites specifically influencing the growth of grassland plants.

    Science.gov (United States)

    Zaller, Johann G; Wechselberger, Katharina F; Gorfer, Markus; Hann, Patrick; Frank, Thomas; Wanek, Wolfgang; Drapela, Thomas

    Earthworms (Annelida: Oligochaeta) deposit several tons per hectare of casts enriched in nutrients and/or arbuscular mycorrhizal fungi (AMF) and create a spatial and temporal soil heterogeneity that can play a role in structuring plant communities. However, while we begin to understand the role of surface casts, it is still unclear to what extent plants utilize subsurface casts. We conducted a greenhouse experiment using large mesocosms (volume 45 l) to test whether (1) soil microsites consisting of earthworm casts with or without AMF (four Glomus taxa) affect the biomass production of 11 grassland plant species comprising the three functional groups grasses, forbs, and legumes, (2) different ecological groups of earthworms (soil dwellers- Aporrectodea caliginosa vs. vertical burrowers- Lumbricus terrestris ) alter potential influences of soil microsites (i.e., four earthworms × two subsurface microsites × two AMF treatments). Soil microsites were artificially inserted in a 25-cm depth, and afterwards, plant species were sown in a regular pattern; the experiment ran for 6 months. Our results show that minute amounts of subsurface casts (0.89 g kg -1 soil) decreased the shoot and root production of forbs and legumes, but not that of grasses. The presence of earthworms reduced root biomass of grasses only. Our data also suggest that subsurface casts provide microsites from which root AMF colonization can start. Ecological groups of earthworms did not differ in their effects on plant production or AMF distribution. Taken together, these findings suggest that subsurface earthworm casts might play a role in structuring plant communities by specifically affecting the growth of certain functional groups of plants.

  13. Does plant diversity affect the water balance of established grassland systems?

    Science.gov (United States)

    Leimer, Sophia; Bischoff, Sebastian; Blaser, Stefan; Boch, Steffen; Busch, Verena; Escher, Peter; Fischer, Markus; Kaupenjohann, Martin; Kerber, Katja; Klaus, Valentin; Michalzik, Beate; Prati, Daniel; Schäfer, Deborah; Schmitt, Barbara; Schöning, Ingo; Schwarz, Martin T.; Siemens, Jan; Thieme, Lisa; Wilcke, Wolfgang

    2017-04-01

    The water cycle drives nutrient cycles and plant productivity. The impact of land use on the water cycle has been extensively studied and there is experimental evidence that biodiversity modifies the water cycle in grasslands. However, the combined influences of land-use and associated biodiversity on the water cycle in established land-use systems are unclear. Therefore, we investigated how evapotranspiration (ETa), downward water flux (DF), and capillary rise (CR) in topsoil and subsoil are related to land-use and plant diversity in established, commercially managed grassland and compared these results to findings from experiments where plant diversity was manipulated. In three Central European regions ("Biodiversity Exploratories"), we studied 29 grassland plots (50 m x 50 m; 9-11 plots per region) from 2010 to 2015. The land-use types cover pasture, mown pasture, and meadow in at least triplicate per region. On each plot, we measured soil water contents, meteorological data (hourly resolution), cumulative precipitation (biweekly), plant species richness, the number of plants in the functional groups of grasses, herbs, and legumes (annually), and root biomass (once). Potential evapotranspiration (ETp) was calculated from meteorological data per plot. Missing data points of ETp and soil water contents were estimated with Bayesian hierarchical models. ETa, DF, and CR were calculated for two soil layers with a soil water balance model. The model is based on changes in soil water storage between subsequent observation dates and ETp, which was partitioned between soil layers according to root distribution. Water fluxes in annual resolution were statistically analyzed for land-use and biodiversity effects using repeated-measures analysis of variance (ANOVA). Land-use type did not affect water fluxes. Species richness did not influence DF and CR. DF from topsoil was higher on plots with more grass species, which is opposite to the results from a manipulative

  14. Distribution of dominant arbuscular mycorrhizal fungi among five plant species in undisturbed vegetation of a coastal grassland

    DEFF Research Database (Denmark)

    Holtgrewe-Stukenbrock, Eva; Rosendahl, Søren

    2005-01-01

    Most plant species in mixed grassland vegetation are colonized by arbuscular mycorrhizal (AM) fungi. Previous studies have reported differences in host preferences among AM fungi, although the fungi are known to lack host specificity. In the present study, the distribution of phylogenetic groups...... of AM fungi belonging to a clade of Glomus species was studied in five plant species from a coastal grassland in Denmark. The occurrence of the fungi was determined by PCR analyses of fungal large subunit ribosomal DNA sequences amplified from root fragments using a specific primer set. The results...... showed that the dominant Glomus species were able to colonize all the studied plant species, supporting the view that the AM fungi represent a large underground interconnecting mycelial network....

  15. Plant effects on soil carbon storage and turnover in montane beech (Nothofagus) forest and adjacent tussock grassland in New Zealand

    International Nuclear Information System (INIS)

    Tate, K.R.; Scott, N.A.; Ross, D.J.; Parshotam, A.; Claydon, J.J.

    2000-01-01

    Land cover is a critical factor that influences, and is influenced by, atmospheric chemistry and potential climate changes. As considerable uncertainty exists about the effects of differences in land cover on below-ground carbon (C) storage, we have compared soil C contents and turnover at adjacent, unmanaged, indigenous forest (Nothofagus solandri var. cliffortiodes) and grassland (Chionochloa pallens) sites near the timberline in the same climo-edaphic environment in Craigieburn Forest Park, Canterbury, New Zealand. Total soil profile C was 13% higher in the grassland than in the forest ( 19.9 v. 16.7 kg/m 2 ), and based on bomb 14 C measurements, the differences mainly resulted from more recalcitrant soil C in the grassland (5.3 v. 3.0 kg/m 2 ). Estimated annual net primary production was about 0.4 kg C/m 2 for the forest and 0.5 kg C/m 2 for the grassland; estimated annual root production was about 0.2 and 0.4 kg C/m 2 , respectively. In situ soil surface CO 2 -C production was similar in the grassland and the forest. The accumulation of recalcitrant soil C was unrelated to differences in mineral weathering or soil texture, but was apparently enhanced by greater soil water retention in the grassland ecosystem. Thus, contrary to model (ROTHC) predictions, this soil C fraction could be expected to respond to the effects of climate change on precipitation patterns. Overall, our results suggest that the different patterns of soil C accumulation in these ecosystems have resulted from differences in plant C inputs, soil aluminium, and soil physical characteristics, rather than from differences in soil mineral weathering or texture. Copyright (2000) CSIRO Australia

  16. Balance matters : N:P stoichiometry and plant diversity in grassland ecosystems

    NARCIS (Netherlands)

    Fujita, Y.

    2010-01-01

    Eutrophication of Nitrogen (N) and Phosphorus (P) is threatening the functioning and biodiversity of grassland ecosystems. A well known effect of eutrophication on grasslands is an increase of above-ground productivity, which intensifies light competition and allows only a few competitive species to

  17. Vascular plants and a brief history of the Kiowa and Rita Blanca National Grasslands

    Science.gov (United States)

    Donald L. Hazlett; Michael H. Schiebout; Paulette L. Ford

    2009-01-01

    Administered by the USDA Forest Service, the Kiowa and Rita Blanca National Grasslands occupy 230,000 acres of public land extending from northeastern New Mexico into the panhandles of Oklahoma and Texas. A mosaic of topographic features including canyons, plateaus, rolling grasslands and outcrops supports a diverse flora. Eight hundred twenty six (826) species of...

  18. Ecosystem-scale fluxes in seminatural Pyrenean grasslands: role of annual dynamics of plant functional types

    Science.gov (United States)

    Altimir, Nuria; Ibañez, Mercedes; Elbers, Jan; Rota, Cristina; Arias, Claudia; Carrara, Arnaud; Nogues, Salvador; Sebastia, Maria-Teresa

    2013-04-01

    The net ecosystem exchange (NEE) and the annual C balance of a site are in general modulated by light, temperature and availability of water and other resources to the plants. In grasslands, NEE is expected to depend strongly on the vegetation with a relationship that can be summarized by the above-ground biomass, its amount and dynamics. Any factor controlling the amount of green biomass is expected to have a strong impact on the short-term NEE, such as amount of solar radiation, water availability and grazing pressure. These controls are modulated differently depending on the plant functional type enduring them. Furthermore, as different guilds follow different functional strategies for optimization of the resources, they also present different patterns of change in their capacities such as photosynthetic fixation, belowground C allocation, and C loss via respiration. We examined these relationships at several semi-natural pastures to determine how the seasonal distribution of plant functional types is detected in the short-term ecosystem exchange and what role it plays. We have looked into these patterns to determine the general variation of key processes and whether different temporal patterns arise between different guilds. The study sites are in the Pyrenees, on the mountain pastures of La Bertolina, Alinyà, and Castellar at 1300, 1700, 1900 m a.s.l. respectively. We performed ecosystem-scale flux measurements by means of micrometeorologial stations combined with a thorough description of the vegetation including below- and above-ground biomass and leaf area as well as monitoring of natural abundance of C isotopes, discriminated by plant functional types. We present here the results of the study.

  19. Local variation in conspecific plant density influences plant-soil feedback in a natural grassland

    NARCIS (Netherlands)

    Kos, M.; Veendrick, Johan; Bezemer, T.M.

    2013-01-01

    Several studies have argued that under field conditions plant–soil feedback may be related to the local density of a plant species, but plant–soil feedback is often studied by comparing conspecific and heterospecific soils or by using mixed soil samples collected from different locations and plant

  20. Contribution of above- and below-ground plant traits to the structure and function of grassland soil microbial communities.

    Science.gov (United States)

    Legay, N; Baxendale, C; Grigulis, K; Krainer, U; Kastl, E; Schloter, M; Bardgett, R D; Arnoldi, C; Bahn, M; Dumont, M; Poly, F; Pommier, T; Clément, J C; Lavorel, S

    2014-10-01

    Abiotic properties of soil are known to be major drivers of the microbial community within it. Our understanding of how soil microbial properties are related to the functional structure and diversity of plant communities, however, is limited and largely restricted to above-ground plant traits, with the role of below-ground traits being poorly understood. This study investigated the relative contributions of soil abiotic properties and plant traits, both above-ground and below-ground, to variations in microbial processes involved in grassland nitrogen turnover. In mountain grasslands distributed across three European sites, a correlative approach was used to examine the role of a large range of plant functional traits and soil abiotic factors on microbial variables, including gene abundance of nitrifiers and denitrifiers and their potential activities. Direct effects of soil abiotic parameters were found to have the most significant influence on the microbial groups investigated. Indirect pathways via plant functional traits contributed substantially to explaining the relative abundance of fungi and bacteria and gene abundances of the investigated microbial communities, while they explained little of the variance in microbial activities. Gene abundances of nitrifiers and denitrifiers were most strongly related to below-ground plant traits, suggesting that they were the most relevant traits for explaining variation in community structure and abundances of soil microbes involved in nitrification and denitrification. The results suggest that consideration of plant traits, and especially below-ground traits, increases our ability to describe variation in the abundances and the functional characteristics of microbial communities in grassland soils. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Assessing the Roles of Fire Frequency and Precipitation in Determining Woody Plant Expansion in Central U.S. Grasslands

    Science.gov (United States)

    Brunsell, N. A.; Van Vleck, E. S.; Nosshi, M.; Ratajczak, Z.; Nippert, J. B.

    2017-10-01

    Woody plant expansion into grasslands and savannas is occurring and accelerating worldwide and often impacts ecosystem processes. Understanding and predicting the environmental and ecological impacts of encroachment has led to a variety of methodologies for assessing its onset, transition, and stability, generally relying on dynamical systems approaches. Here we continue this general line of investigation to facilitate the understanding of the roles of precipitation frequency and intensity and fire frequency on the conversion of grasslands to woody-dominated systems focusing on the central United States. A low-dimensional model with stochastic precipitation and fire disturbance is introduced to examine the complex interactions between precipitation and fire as mechanisms that may suppress or facilitate increases in woody cover. By using Lyapunov exponents, we are able to ascertain the relative control exerted on woody encroachment through these mechanisms. Our results indicate that precipitation frequency is a more important control on woody encroachment than the intensity of individual precipitation events. Fire, however, exerts a much more dominant impact on the limitation of encroachment over the range of precipitation variability considered here. These results indicate that fire management may be an effective strategy to slow the onset of woody species into grasslands. While climate change might predict a reduced potential for woody encroachment in the near future, these results indicate a reduction in woody fraction may be unlikely when considering anthropogenic fire suppression.

  2. Hazard identification based on plant functional modelling

    International Nuclear Information System (INIS)

    Rasmussen, B.; Whetton, C.

    1993-10-01

    A major objective of the present work is to provide means for representing a process plant as a socio-technical system, so as to allow hazard identification at a high level. The method includes technical, human and organisational aspects and is intended to be used for plant level hazard identification so as to identify critical areas and the need for further analysis using existing methods. The first part of the method is the preparation of a plant functional model where a set of plant functions link together hardware, software, operations, work organisation and other safety related aspects of the plant. The basic principle of the functional modelling is that any aspect of the plant can be represented by an object (in the sense that this term is used in computer science) based upon an Intent (or goal); associated with each Intent are Methods, by which the Intent is realized, and Constraints, which limit the Intent. The Methods and Constraints can themselves be treated as objects and decomposed into lower-level Intents (hence the procedure is known as functional decomposition) so giving rise to a hierarchical, object-oriented structure. The plant level hazard identification is carried out on the plant functional model using the Concept Hazard Analysis method. In this, the user will be supported by checklists and keywords and the analysis is structured by pre-defined worksheets. The preparation of the plant functional model and the performance of the hazard identification can be carried out manually or with computer support. (au) (4 tabs., 10 ills., 7 refs.)

  3. Comparison of remote sensing and plant trait-based modelling to predict ecosystem services in subalpine grasslands

    Czech Academy of Sciences Publication Activity Database

    Homolová, Lucie; Schaepman, M. E.; Lamarque, L.; Clevers, J.G.P.W.; de Bello, Francesco; Thuiller, W.; Lavorel, S.

    2014-01-01

    Roč. 5, č. 8 (2014), č. článku 100. ISSN 2150-8925 Institutional support: RVO:67179843 ; RVO:67985939 Keywords : land-use change * leaf chlorophyll content * imaging spectroscopy * water-content * aviris data * spectral reflectance * hyperspectral data * species richness * area index * vegetation * aisa * biomass * ecosystem properties * ecosystem services * linear regression * remote sensing * spatial heterogeneity * subalpine grasslands Subject RIV: EH - Ecology, Behaviour; EF - Botanics (BU-J) OBOR OECD: Remote sensing; Plant sciences, botany (BU-J) Impact factor: 2.255, year: 2014

  4. Disturbance is required for CO2-dependent promotion of woody plant growth in grasslands

    DEFF Research Database (Denmark)

    Loveys, Beth R.; Egerton, John J. G.; Bruhn, Dan

    2010-01-01

    The relative effects of disturbance (here defined as bare soil), competition for edaphic resources, thermal interference and elevated [CO2] on growth of tree seedlings in grasslands were studied under field conditions. Snow gum (Eucalyptus pauciflora Sieb. ex Spreng.) seedlings were grown in open...

  5. Grassland Arthropods Are Controlled by Direct and Indirect Interactions with Cattle but Are Largely Unaffected by Plant Provenance.

    Science.gov (United States)

    Farrell, Kelly Anne; Harpole, W Stanley; Stein, Claudia; Suding, Katharine N; Borer, Elizabeth T

    2015-01-01

    Cattle grazing and invasion by non-native plant species are globally-ubiquitous changes occurring to plant communities that are likely to reverberate through whole food webs. We used a manipulative field experiment to quantify how arthropod community structure differed in native and non-native California grassland communities in the presence and absence of grazing. The arthropod community was strongly affected by cattle grazing: the biovolume of herbivorous arthropods was 79% higher in grazed than ungrazed plots, whereas the biovolume of predatory arthropods was 13% higher in ungrazed plots. In plots where non-native grasses were grazed, arthropod biovolume increased, possibly in response to increased plant productivity or increased nutritional quality of rapidly-growing annual plants. Grazing may thus affect plant biomass both through the direct removal of biomass, and through arthropod-mediated impacts. We also expected the arthropod community to differ between native and non-native plant communities; surprisingly, arthropod richness and diversity did not vary consistently between these grass community types, although arthropod abundance was slightly higher in plots with native and ungrazed grasses. These results suggest that whereas cattle grazing affects the arthropod community via direct and indirect pathways, arthropod community changes commonly associated with non-native plant invasions may not be due to the identity or dominance of the invasive species in those systems, but to accompanying changes in plant traits or functional group composition, not seen in this experiment because of the similarity of the plant communities.

  6. Grassland Arthropods Are Controlled by Direct and Indirect Interactions with Cattle but Are Largely Unaffected by Plant Provenance.

    Directory of Open Access Journals (Sweden)

    Kelly Anne Farrell

    Full Text Available Cattle grazing and invasion by non-native plant species are globally-ubiquitous changes occurring to plant communities that are likely to reverberate through whole food webs. We used a manipulative field experiment to quantify how arthropod community structure differed in native and non-native California grassland communities in the presence and absence of grazing. The arthropod community was strongly affected by cattle grazing: the biovolume of herbivorous arthropods was 79% higher in grazed than ungrazed plots, whereas the biovolume of predatory arthropods was 13% higher in ungrazed plots. In plots where non-native grasses were grazed, arthropod biovolume increased, possibly in response to increased plant productivity or increased nutritional quality of rapidly-growing annual plants. Grazing may thus affect plant biomass both through the direct removal of biomass, and through arthropod-mediated impacts. We also expected the arthropod community to differ between native and non-native plant communities; surprisingly, arthropod richness and diversity did not vary consistently between these grass community types, although arthropod abundance was slightly higher in plots with native and ungrazed grasses. These results suggest that whereas cattle grazing affects the arthropod community via direct and indirect pathways, arthropod community changes commonly associated with non-native plant invasions may not be due to the identity or dominance of the invasive species in those systems, but to accompanying changes in plant traits or functional group composition, not seen in this experiment because of the similarity of the plant communities.

  7. Grassland Sustainability

    Science.gov (United States)

    Deborah U. Potter; Paulette L. Ford

    2004-01-01

    In this chapter we discuss grassland sustainability in the Southwest, grassland management for sustainability, national and local criteria and indicators of sustainable grassland ecosystems, and monitoring for sustainability at various scales. Ecological sustainability is defined as: [T]he maintenance or restoration of the composition, structure, and processes of...

  8. Plant diversity moderates drought stress in grasslands: Implications from a large real-world study on "1"3C natural abundances

    International Nuclear Information System (INIS)

    Klaus, Valentin H.; Hölzel, Norbert; Prati, Daniel; Schmitt, Barbara; Schöning, Ingo; Schrumpf, Marion; Solly, Emily F.; Hänsel, Falk; Fischer, Markus; Kleinebecker, Till

    2016-01-01

    Land-use change and intensification play a key role in the current biodiversity crisis. The resulting species loss can have severe effects on ecosystem functions and services, thereby increasing ecosystem vulnerability to climate change. We explored whether land-use intensification (i.e. fertilization intensity), plant diversity and other potentially confounding environmental factors may be significantly related to water use (i.e. drought stress) of grassland plants. Drought stress was assessed using δ"1"3C abundances in aboveground plant biomass of 150 grassland plots across a gradient of land-use intensity. Under water shortage, plants are forced to increasingly take up the heavier "1"3C due to closing stomata leading to an enrichment of "1"3C in biomass. Plants were sampled at the community level and for single species, which belong to three different functional groups (one grass, one herb, two legumes). Results show that plant diversity was significantly related to the δ"1"3C signal in community, grass and legume biomass indicating that drought stress was lower under higher diversity, although this relation was not significant for the herb species under study. Fertilization, in turn, mostly increased drought stress as indicated by more positive δ"1"3C values. This effect was mostly indirect by decreasing plant diversity. In line with these results, we found similar patterns in the δ"1"3C signal of the organic matter in the topsoil, indicating a long history of these processes. Our study provided strong indication for a positive biodiversity-ecosystem functioning relationship with reduced drought stress at higher plant diversity. However, it also underlined a negative reinforcing situation: as land-use intensification decreases plant diversity in grasslands, this might subsequently increases drought sensitivity. Vice-versa, enhancing plant diversity in species-poor agricultural grasslands may moderate negative effects of future climate change. - Highlights

  9. Plant diversity moderates drought stress in grasslands: Implications from a large real-world study on {sup 13}C natural abundances

    Energy Technology Data Exchange (ETDEWEB)

    Klaus, Valentin H., E-mail: v.klaus@uni-muenster.de [Münster University, Institute for Landscape Ecology, Heisenbergstr. 2, 48149 Münster (Germany); Hölzel, Norbert [Münster University, Institute for Landscape Ecology, Heisenbergstr. 2, 48149 Münster (Germany); Prati, Daniel; Schmitt, Barbara [University of Bern, Institute of Plant Sciences, Altenbergrain 21, 3013 Bern (Switzerland); Schöning, Ingo; Schrumpf, Marion; Solly, Emily F. [Max-Planck-Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745 Jena (Germany); Hänsel, Falk [University Marburg, Environmental Informatics, Faculty of Geography, Deutschhausstr. 12, 35037 Marburg (Germany); Fischer, Markus [University of Bern, Institute of Plant Sciences, Altenbergrain 21, 3013 Bern (Switzerland); Kleinebecker, Till [Münster University, Institute for Landscape Ecology, Heisenbergstr. 2, 48149 Münster (Germany)

    2016-10-01

    Land-use change and intensification play a key role in the current biodiversity crisis. The resulting species loss can have severe effects on ecosystem functions and services, thereby increasing ecosystem vulnerability to climate change. We explored whether land-use intensification (i.e. fertilization intensity), plant diversity and other potentially confounding environmental factors may be significantly related to water use (i.e. drought stress) of grassland plants. Drought stress was assessed using δ{sup 13}C abundances in aboveground plant biomass of 150 grassland plots across a gradient of land-use intensity. Under water shortage, plants are forced to increasingly take up the heavier {sup 13}C due to closing stomata leading to an enrichment of {sup 13}C in biomass. Plants were sampled at the community level and for single species, which belong to three different functional groups (one grass, one herb, two legumes). Results show that plant diversity was significantly related to the δ{sup 13}C signal in community, grass and legume biomass indicating that drought stress was lower under higher diversity, although this relation was not significant for the herb species under study. Fertilization, in turn, mostly increased drought stress as indicated by more positive δ{sup 13}C values. This effect was mostly indirect by decreasing plant diversity. In line with these results, we found similar patterns in the δ{sup 13}C signal of the organic matter in the topsoil, indicating a long history of these processes. Our study provided strong indication for a positive biodiversity-ecosystem functioning relationship with reduced drought stress at higher plant diversity. However, it also underlined a negative reinforcing situation: as land-use intensification decreases plant diversity in grasslands, this might subsequently increases drought sensitivity. Vice-versa, enhancing plant diversity in species-poor agricultural grasslands may moderate negative effects of future

  10. New Pesticidal Diterpenoids from Vellozia gigantea (Velloziaceae, an Endemic Neotropical Plant Living in the Endangered Brazilian Biome Rupestrian Grasslands

    Directory of Open Access Journals (Sweden)

    Mariana C. Ferreira

    2017-01-01

    Full Text Available Vellozia gigantea is a rare, ancient, and endemic neotropical plant present in the Brazilian Rupestrian grasslands. The dichloromethane extract of V. gigantea adventitious roots was phytotoxic against Lactuca sativa, Agrostis stolonifera, and Lemna paucicostata, and showed larvicidal activity against Aedes aegypti. Phytotoxicity bioassay-directed fractionation of the extract revealed one new isopimaradiene, 8(9,15-isopimaradien-1,3,7,11-tetraone, and three new cleistanthane diterpenoids, 7-oxo-8,11,13-cleistanthatrien-3-ol, 3,20-epoxy-7-oxo-8,11,13-cleistanthatrien-3-ol, and 20-nor-3,7-dioxo-1,8,11,13-cleistanthatetraen-10-ol. These new structures are proposed based on interpretation of 1H, 13C, COSY, NOESY, HSQC, and HMBC NMR data. 8(9,15-isopimaradien-1,3,7,11-tetraone was especially phytotoxic with an IC50 value (30 μM comparable to those of commercial herbicides clomazone, EPTC, and naptalam. In addition, 7-oxo-8,11,13-cleistanthatrien-3-ol provided 100% mortality at a concentration of 125 ppm against one-day-old Ae. aegypti larvae. Our results show that ancient and unique plants, like the endangered narrowly endemic neotropical species V. gigantea present in the Rupestrian grasslands, should also be protected because they can be sources of new bioactive compounds.

  11. Seed-bank structure and plant-recruitment conditions regulate the dynamics of a grassland-shrubland Chihuahuan ecotone.

    Science.gov (United States)

    Moreno-de Las Heras, Mariano; Turnbull, Laura; Wainwright, John

    2016-09-01

    Large areas of desert grasslands in the southwestern United States have shifted to sparse shrublands dominated by drought-tolerant woody species over the last 150 yr, accompanied by accelerated soil erosion. An important step toward the understanding of patterns in species dominance and vegetation change at desert grassland-shrubland transitions is the study of environmental limitations imposed by the shrub-encroachment phenomenon on plant establishment. Here, we analyze the structure of soil seed banks, environmental limitations for seed germination (i.e., soil-water availability and temperature), and simulated seedling emergence and early establishment of dominant species (black grama, Bouteloua eriopoda, and creosotebush, Larrea tridentata) across a Chihuahuan grassland-shrubland ecotone (Sevilleta National Wildlife Refuge, New Mexico, USA). Average viable seed density in soils across the ecotone is generally low (200-400 seeds/m 2 ), although is largely concentrated in densely vegetated areas (with peaks up to 800-1,200 seeds/m 2 in vegetated patches). Species composition in the seed bank is strongly affected by shrub encroachment, with seed densities of grass species sharply decreasing in shrub-dominated sites. Environmental conditions for seed germination and seedling emergence are synchronized with the summer monsoon. Soil-moisture conditions for seedling establishment of B. eriopoda take place with a recurrence interval ranging between 5 and 8 yr for grassland and shrubland sites, respectively, and are favored by strong monsoonal precipitation. Limited L. tridentata seed dispersal and a narrow range of rainfall conditions for early seedling establishment (50-100 mm for five to six consecutive weeks) constrain shrub-recruitment pulses to localized and episodic decadal events (9-25 yr recurrence intervals) generally associated with late-summer rainfall. Re-establishment of B. eriopoda in areas now dominated by L. tridentata is strongly limited by the

  12. Non-random co-occurrence of native and exotic plant species in Mediterranean grasslands

    Science.gov (United States)

    de Miguel, José M.; Martín-Forés, Irene; Acosta-Gallo, Belén; del Pozo, Alejandro; Ovalle, Carlos; Sánchez-Jardón, Laura; Castro, Isabel; Casado, Miguel A.

    2016-11-01

    Invasion by exotic species in Mediterranean grasslands has determined assembly patterns of native and introduced species, knowledge of which provides information on the ecological processes underlying these novel communities. We considered grasslands from Spain and Chile. For each country we considered the whole grassland community and we split species into two subsets: in Chile, species were classified as natives or colonizers (i.e. exotics); in Spain, species were classified as exclusives (present in Spain but not in Chile) or colonizers (Spanish natives and exotics into Chile). We used null models and co-occurrence indices calculated in each country for each one of 15 sites distributed along a precipitation gradient and subjected to similar silvopastoral exploitation. We compared values of species co-occurrence between countries and between species subsets (natives/colonizers in Chile; exclusives/colonizers in Spain) within each country and we characterised them according to climatic variables. We hypothesized that: a) the different coexistence time of the species in both regions should give rise to communities presenting a spatial pattern further from random in Spain than in Chile, b) the co-occurrence patterns in the grasslands are affected by mesoclimatic factors in both regions. The patterns of co-occurrence are similar in Spain and Chile, mostly showing a spatial pattern more segregated than expected by random. The colonizer species are more segregated in Spain than in Chile, possibly determined by the longer residence time of the species in the source area than in the invaded one. The segregation of species in Chile is related to water availability, being species less segregated in habitat with greater water deficit; in Spain no relationship with climatic variables was found. After an invasion process, our results suggest that the possible process of alteration of the original Chilean communities has not prevented the assembly between the native and

  13. Impact of soil warming on the plant metabolome of Icelandic grasslands

    Czech Academy of Sciences Publication Activity Database

    Gargallo-Garriga, A.; Ayala-Roque, M.; Sardans, J.; Bartrons, M.; Granda, V.; Sigurdsson, B. D.; Leblans, N. I.W.; Oravec, Michal; Urban, Otmar; Janssens, I. A.; Peñuelas, J.

    2017-01-01

    Roč. 7, č. 3 (2017), č. článku 44. E-ISSN 2218-1989 R&D Projects: GA MŠk(CZ) LM2015061; GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : Climate change * Geothermal bedrock channels * Grassland * Iceland * Metabolome * Warming Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7)

  14. Soil microbial community structure is unaltered by plant invasion, vegetation clipping, and nitrogen fertilization in experimental semi-arid grasslands

    Directory of Open Access Journals (Sweden)

    Chelsea J Carey

    2015-05-01

    Full Text Available Global and regional environmental changes often co-occur, creating complex gradients of disturbance on the landscape. Soil microbial communities are an important component of ecosystem response to environmental change, yet little is known about how microbial structure and function respond to multiple disturbances, or whether multiple environmental changes lead to unanticipated interactive effects. Our study used experimental semi-arid grassland plots in a Mediterranean-climate to determine how soil microbial communities in a seasonally variable ecosystem respond to one, two, or three simultaneous environmental changes: exotic plant invasion, plant invasion + vegetation clipping (to simulate common management practices like mowing or livestock grazing, plant invasion + nitrogen (N fertilization, and plant invasion + clipping + N fertilization. We examined microbial community structure 5-6 years after plot establishment via sequencing of >1 million 16S rRNA genes. Abiotic soil properties (soil moisture, temperature, pH, and inorganic N and microbial functioning (nitrification and denitrification potentials were also measured and showed treatment-induced shifts, including altered NO3- availability, temperature, and nitrification potential. Despite these changes, bacterial and archaeal communities showed little variation in composition and diversity across treatments. Even communities in plots exposed to three interacting environmental changes were similar to those in restored native grassland plots. Historical exposure to large seasonal and inter-annual variations in key soil properties, in addition to prior site cultivation, may select for a functionally plastic or largely dormant microbial community, resulting in a microbial community that is structurally robust to single and multiple environmental changes.

  15. Weed suppression greatly increased by plant diversity in intensively managed grasslands: A continental-scale experiment.

    Science.gov (United States)

    Connolly, John; Sebastià, Maria-Teresa; Kirwan, Laura; Finn, John Anthony; Llurba, Rosa; Suter, Matthias; Collins, Rosemary P; Porqueddu, Claudio; Helgadóttir, Áslaug; Baadshaug, Ole H; Bélanger, Gilles; Black, Alistair; Brophy, Caroline; Čop, Jure; Dalmannsdóttir, Sigridur; Delgado, Ignacio; Elgersma, Anjo; Fothergill, Michael; Frankow-Lindberg, Bodil E; Ghesquiere, An; Golinski, Piotr; Grieu, Philippe; Gustavsson, Anne-Maj; Höglind, Mats; Huguenin-Elie, Olivier; Jørgensen, Marit; Kadziuliene, Zydre; Lunnan, Tor; Nykanen-Kurki, Paivi; Ribas, Angela; Taube, Friedhelm; Thumm, Ulrich; De Vliegher, Alex; Lüscher, Andreas

    2018-03-01

    Grassland diversity can support sustainable intensification of grassland production through increased yields, reduced inputs and limited weed invasion. We report the effects of diversity on weed suppression from 3 years of a 31-site continental-scale field experiment.At each site, 15 grassland communities comprising four monocultures and 11 four-species mixtures based on a wide range of species' proportions were sown at two densities and managed by cutting. Forage species were selected according to two crossed functional traits, "method of nitrogen acquisition" and "pattern of temporal development".Across sites, years and sown densities, annual weed biomass in mixtures and monocultures was 0.5 and 2.0 t  DM ha -1 (7% and 33% of total biomass respectively). Over 95% of mixtures had weed biomass lower than the average of monocultures, and in two-thirds of cases, lower than in the most suppressive monoculture (transgressive suppression). Suppression was significantly transgressive for 58% of site-years. Transgressive suppression by mixtures was maintained across years, independent of site productivity.Based on models, average weed biomass in mixture over the whole experiment was 52% less (95% confidence interval: 30%-75%) than in the most suppressive monoculture. Transgressive suppression of weed biomass was significant at each year across all mixtures and for each mixture.Weed biomass was consistently low across all mixtures and years and was in some cases significantly but not largely different from that in the equiproportional mixture. The average variability (standard deviation) of annual weed biomass within a site was much lower for mixtures (0.42) than for monocultures (1.77). Synthesis and applications . Weed invasion can be diminished through a combination of forage species selected for complementarity and persistence traits in systems designed to reduce reliance on fertiliser nitrogen. In this study, effects of diversity on weed suppression were

  16. Does interspecific competition alter effects of early season ozone exposure on plants from wet grasslands? Results of a three-year experiment in open-top chambers

    NARCIS (Netherlands)

    Tonneijck, A.E.G.; Franzaring, J.; Brouwer, G.; Metselaar, K.; Dueck, T.A.

    2004-01-01

    Chronic effects of ozone on wet grassland species early in the growing season might be altered by interspecific competition. Individual plants of Holcus lanatus, Lychnis flos-cuculi, Molinia caerulea and Plantago lanceolata were grown in monocultures and in mixed cultures with Agrostis capillaris.

  17. Impact of Altered Precipitation Patterns on Plant Productivity and Soil Respiration in a Northern Great Plains Grassland

    Science.gov (United States)

    Haase, L.; Flanagan, L. B.

    2017-12-01

    Precipitation patterns are expected to shift towards larger but fewer rain events, with longer intermittent dry periods, associated with climate change. The larger rain events may compensate for and help to mitigate climate change effects on key ecosystem functions such as plant productivity and soil respiration in semi-arid grasslands. We experimentally manipulated the amount and frequency of simulated precipitation added to trenched, treatment plots that were covered by rain shelters, and measured the response in plant productivity and soil respiration in a native, grassland ecosystem near Lethbridge, Alberta. We compared the observed responses to the predictions of a conceptual ecosystem response model developed by Knapp et al. 2008 (BioScience 58: 811-821). Two experiments were conducted during 14 weeks of the growing season from May-August. The first experiment (normal amount) applied total growing season precipitation of 180 mm (climate normal), and the second experiment (reduced amount) applied total precipitation of 90 mm. In both experiments, precipitation was applied at two frequencies, 1 rain event every week (normal frequency) and 1 rain event every two weeks (reduced frequency). In the normal amount experiment, the average rain event was 12.8 mm for the normal frequency treatment and 25.8 mm for the reduced frequency treatment. In the reduced amount experiment, the average rain event was 6.4 mm for the normal frequency treatment and 12.8 mm for the reduced frequency treatment. We hypothesized that larger but fewer rain events would result in increased plant productivity and soil respiration for both experiments. Plant greenness values calculated from digital photographs were used as a proxy for plant productivity, and showed significantly higher values for the normal vs. reduced amount experiment. Soil respiration rate also showed significantly higher values for the normal vs. reduced amount experiment. No significant treatment effect could be detected

  18. The effect of solar UV radiation of four plant species occurring in a coastal grassland vegetation in The Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Tosserams, M.; Rozema, J. [Vrije Univ., Dept. of Ecology and Ecotoxicology, Amsterdam (Netherlands); Pais, A. de Sa [Univ. de Tras-os-Montes e Alto Douro, Vila Real (Portugal)

    1996-09-01

    During the summer of 1992, growth and some physiological parameters of four native plant species occurring in a coastal grassland in The Netherlands, were studied after reduction of solar UV irradiance using different cut-off filters. Biomass production, morphology and photosynthesis of all species tested were unaffected by the different treatments. Litter production of Plantago lanceolata was increased in the absence of the total UV waveband, indicating a possible role for this waveband in plant senescence. Depletion of the total UV waveband from sunlight resulted in alterations in biomass allocation in Calamagrostis epigeios and Urtica dioica while no changes were observed in P. lanceolatata and Verbascum thapsus. In C. epigeios and increase in the specific leaf area was observed, whereas in U. dioica root weight per total plant weight was decreased resulting in an increase in the shoot/root ratio. Both photosynthetic and UV-absorbing pigment concentrations were altered by the different filter applications. When compared to control plants receiving full sunlight, depletion of UV-B resulted in a significant increase in chlorophyll concentration in U. dioica leaves, this however did not affect photosynthetic rate. The presence of UV-B radiation enhanced the UV-absorbance of leaf extract of all species except P. lanceolata. Optical characteristics of the leaves were also changed. Both the quantity (P. lanceolata and U. dioica) and the quality (all species) of radiation transmitted by the leaves was affected by the different treatments. (au) 44 refs.

  19. Effects of soil depth and plant-soil interaction on microbial community in temperate grasslands of northern China.

    Science.gov (United States)

    Yao, Xiaodong; Zhang, Naili; Zeng, Hui; Wang, Wei

    2018-07-15

    Although the patterns and drivers of soil microbial community composition are well studied, little is known about the effects of plant-soil interactions and soil depth on soil microbial distribution at a regional scale. We examined 195 soil samples from 13 sites along a climatic transect in the temperate grasslands of northern China to measure the composition of and factors influencing soil microbial communities within a 1-m soil profile. Soil microbial community composition was measured using phospholipid fatty acids (PLFA) analysis. Fungi predominated in topsoil (0-10 cm) and bacteria and actinomycetes in deep soils (40-100 cm), independent of steppe types. This variation was explained by contemporary environmental factors (including above- and below-ground plant biomass, soil physicochemical and climatic factors) >58% in the 0-40 cm of soil depth, but soils. Interestingly, when we considered the interactive effects between plant traits (above ground biomass and root biomass) and soil factors (pH, clay content, and soil total carbon, nitrogen, phosphorous), we observed a significant interaction effect occurring at depths of 10-20 cm soil layer, due to different internal and external factors of the plant-soil system along the soil profile. These results improve understanding of the drivers of soil microbial community composition at regional scales. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Relationship between Remote Sensing Data, Plant Biomass and Soil Nitrogen Dynamics in Intensively Managed Grasslands under Controlled Conditions.

    Science.gov (United States)

    Knoblauch, Christoph; Watson, Conor; Berendonk, Clara; Becker, Rolf; Wrage-Mönnig, Nicole; Wichern, Florian

    2017-06-23

    The sustainable use of grasslands in intensive farming systems aims to optimize nitrogen (N) inputs to increase crop yields and decrease harmful losses to the environment at the same time. To achieve this, simple optical sensors may provide a non-destructive, time- and cost-effective tool for estimating plant biomass in the field, considering spatial and temporal variability. However, the plant growth and related N uptake is affected by the available N in the soil, and therefore, N mineralization and N losses. These soil N dynamics and N losses are affected by the N input and environmental conditions, and cannot easily be determined non-destructively. Therefore, the question arises: whether a relationship can be depicted between N fertilizer levels, plant biomass and N dynamics as indicated by nitrous oxide (N₂O) losses and inorganic N levels. We conducted a standardized greenhouse experiment to explore the potential of spectral measurements for analyzing yield response, N mineralization and N₂O emissions in a permanent grassland. Ryegrass was subjected to four mineral fertilizer input levels over 100 days (four harvests) under controlled environmental conditions. The soil temperature and moisture content were automatically monitored, and the emission rates of N₂O and carbon dioxide (CO₂) were detected frequently. Spectral measurements of the swards were performed directly before harvesting. The normalized difference vegetation index (NDVI) and simple ratio (SR) were moderately correlated with an increasing biomass as affected by fertilization level. Furthermore, we found a non-linear response of increasing N₂O emissions to elevated fertilizer levels. Moreover, inorganic N and extractable organic N levels at the end of the experiment tended to increase with the increasing N fertilizer addition. However, microbial biomass C and CO₂ efflux showed no significant differences among fertilizer treatments, reflecting no substantial changes in the soil

  1. Assessment of interspecific interactions in plant communities: an illustration from the cold desert saltbush grasslands of North America

    Science.gov (United States)

    Freeman, Carl D.; Emlen, John M.

    1995-01-01

    Interspecific interactions influence both the productivity and composition of plant communities. Here, we propose new field procedures and analytical approaches for assessing interspecific interactions in nature and apply these procedures to the salt desert shrub grasslands of western Utah. Data were collected from two grazing treatments over a period of 2 years. The proposed equations were fairly consistent across both treatments and years. In addition to illustrating how to assess interspecific interactions within a community, we also develop a new approach for projecting the community composition as a result of some alteration, i.e. increase or decrease in the abundance of one or more species. Results demonstrate competition both within and between plant life-form groups. While introduced annuals were found to depress profoundly the likelihood of perennial plants replacing themselves, perennials had little influence on annuals. Thus, as native perennials die, they are more likely to be replaced by perennials than for the reverse to occur. Our results suggest that unless conditions change, these communities will become increasingly dominated by introduced annuals.

  2. Seasonal variation in nitrogen pools and 15N/13C natural abundances in different tissues of grassland plants

    Directory of Open Access Journals (Sweden)

    J. K. Schjoerring

    2012-05-01

    Full Text Available Seasonal changes in nitrogen (N pools, carbon (C content and natural abundance of 13C and 15N in different tissues of ryegrass plants were investigated in two intensively managed grassland fields in order to address their ammonia (NH3 exchange potential. Green leaves generally had the largest total N concentration followed by stems and inflorescences. Senescent leaves had the lowest N concentration, indicating N re-allocation. The seasonal pattern of the Γ value, i.e. the ratio between NH4+ and H+ concentrations, was similar for the various tissues of the ryegrass plants but the magnitude of Γ differed considerably among the different tissues. Green leaves and stems generally had substantially lower Γ values than senescent leaves and litter. Substantial peaks in Γ were observed during spring and summer in response to fertilization and grazing. These peaks were associated with high NH4+ rather than with low H+ concentrations. Peaks in Γ also appeared during the winter, coinciding with increasing δ15N values, indicating absorption of N derived from mineralization of soil organic matter. At the same time, δ13C values were declining, suggesting reduced photosynthesis and capacity for N assimilation. δ15N and δ13C values were more influenced by mean monthly temperature than by the accumulated monthly precipitation. In conclusion, ryegrass plants showed a clear seasonal pattern in N pools. Green leaves and stems of ryegrass plants generally seem to constitute a sink for NH3, while senescent leaves have a large potential for NH3 emission. However, management events such as fertilisation and grazing may create a high NH3 emission potential even in green plant parts. The obtained results provide input for future modelling of plant-atmosphere NH3 exchange.

  3. The interplay of stress and mowing disturbance for the intensity and importance of plant interactions in dry calcareous grasslands.

    Science.gov (United States)

    Maalouf, Jean-Paul; Le Bagousse-Pinguet, Yoann; Marchand, Lilian; Touzard, Blaise; Michalet, Richard

    2012-09-01

    There is still debate regarding the direction and strength of plant interactions under intermediate to high levels of stress. Furthermore, little is known on how disturbance may interact with physical stress in unproductive environments, although recent theory and models have shown that this interplay may induce a collapse of plant interactions and diversity. The few studies assessing such questions have considered the intensity of biotic interactions but not their importance, although this latter concept has been shown to be very useful for understanding the role of interactions in plant communities. The objective of this study was to assess the interplay between stress and disturbance for plant interactions in dry calcareous grasslands. A field experiment was set up in the Dordogne, southern France, where the importance and intensity of biotic interactions undergone by four species were measured along a water stress gradient, and with and without mowing disturbance. The importance and intensity of interactions varied in a very similar way along treatments. Under undisturbed conditions, plant interactions switched from competition to neutral with increasing water stress for three of the four species, whereas the fourth species was not subject to any significant biotic interaction along the gradient. Responses to disturbance were more species-specific; for two species, competition disappeared with mowing in the wettest conditions, whereas for the two other species, competition switched to facilitation with mowing. Finally, there were no significant interactions for any species in the disturbed and driest conditions. At very high levels of stress, plant performances become too weak to allow either competition or facilitation and disturbance may accelerate the collapse of interactions in dry conditions. The results suggest that the importance and direction of interactions are more likely to be positively related in stressful environments.

  4. Prescribed fire, soil inorganic nitrogen dynamics, and plant responses in a semiarid grassland

    Science.gov (United States)

    David J. Augustine; Paul Brewer; Dana M. Blumenthal; Justin D. Derner; Joseph C. von Fischer

    2014-01-01

    In arid and semiarid ecosystems, fire can potentially affect ecosystem dynamics through changes in soil moisture, temperature, and nitrogen cycling, as well as through direct effects on plant meristem mortality. We examined effects of annual and triennial prescribed fires conducted in early spring on soil moisture, temperature, and N, plant growth, and plant N content...

  5. Comparing arbuscular mycorrhizal communities of individual plants in a grassland biodiversity experiment

    NARCIS (Netherlands)

    Van de Voorde, T.F.J.; Van der Putten, W.H.; Gamper, H.A.; Hol, W.H.G.; Bezemer, T.M.

    2010-01-01

    Plants differ greatly in the soil organisms colonizing their roots. However, how soil organism assemblages of individual plant roots can be influenced by plant community properties remains poorly understood. We determined the composition of arbuscular mycorrhizal fungi (AMF) in Jacobaea vulgaris

  6. Evaluating plant-soil feedback together with competition in a serpentine grassland.

    Science.gov (United States)

    Casper, Brenda B; Castelli, Jeffrey P

    2007-05-01

    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 was expressed through reduced survival and shoot biomass when seedlings were planted within existing clumps of conspecifics compared with clumps of heterospecifics. However, the combined effects of feedback and competition were species-specific. Only Andropogon gerardii exhibited feedback when competition with the clumps was allowed. For Sorghastrum nutans, strong interspecific competition eliminated the feedback expressed in the absence of competition, and Schizachyrium scoparium showed no feedback at all. That arbuscular mycorrhizal (AM) fungi may play a role in the feedback was indicated by higher AM root colonization with conspecific plant neighbours. We suggest that feedback and competition should not be viewed as entirely separate processes and that their importance in structuring plant communities cannot be judged in isolation from each other.

  7. How do plant communities and flower visitors relate? A case study of semi-natural xerothermic grasslands

    Directory of Open Access Journals (Sweden)

    Damian Chmura

    2013-06-01

    Full Text Available The paper examines the relationships between the species composition of flower visitors and plants in the semi-natural xerothermic grasslands in southern and central Poland. Thirty 10 × 10 m permanent plots were laid out in total, mainly in nature reserves. The vegetation units studied were classified according to the Braun-Blanquet system; these were phytocoenoses of the Festuco-Brometea classes Inuletum ensifoliae, Adonido-Brachypodietum pinnati and the transitional plant community. Entomological research was performed using the Pollard method within the same plots. A particular site was visited only once and different sites were studied between April and August 2008. We applied, among others, co-correspondence-analysis Co-CA, detrended correspondence analysis (DCA and redundancy analysis (RDA to investigate the co-occurrence patterns of plants and flower visitors and their biotopic requirements. We found that the species composition of flower visitors cannot be predicted by floristic composition when the duration of the study is restricted to one day (but under similar weather conditions; however, there is a positive relationship between the species richness of insects and plants and a positive relationship between the number of plant species and the abundance of flower visitors. The Ellenberg moisture index and the cover of meadow species significantly explained the species composition of insects. The three various vegetation units and five dominant xerothermic species, i.e. Adonis vernalis, Anemone sylvestris, Inula ensifolia, Linum hirsutum and Carlina onopordifolia that were studied across time differed in the species richness of insects. Our results demonstrate that possible patterns in the species composition and the assembly rules of flower visitors are not apparent when the Pollard method is applied. Based on the data obtained using this method, the flower visiting assemblages seem not to be driven by competition and they primarily

  8. Relationships between Plant Diversity and Grasshopper Diversity and Abundance in the Little Missouri National Grassland

    Directory of Open Access Journals (Sweden)

    David H. Branson

    2011-01-01

    Full Text Available A continuing challenge in orthopteran ecology is to understand what determines grasshopper species diversity at a given site. In this study, the objective was to determine if variation in grasshopper abundance and diversity between 23 sites in western North Dakota (USA could be explained by variation in plant species richness and diversity. In this system with relatively low plant diversity, grasshopper species richness and abundance were not significantly associated with plant species richness in either year. Although a number of significant associations between plant diversity and grasshopper diversity were found through regression analyses, results differed greatly between years indicating that plant species richness and diversity did not lead to strong effects on grasshopper diversity metrics. Plant species richness appears to be too coarse grained to lead to accurate predictions of grasshopper species richness in this system dominated by generalist grasshopper species.

  9. Small-scale barriers mitigate desertification processes and enhance plant recruitment in a degraded semiarid grassland

    Science.gov (United States)

    Fick, Stephen E; Decker, Cheryl E.; Duniway, Michael C.; Miller, Mark E.

    2016-01-01

    Anthropogenic desertification is a problem that plagues drylands globally; however, the factors which maintain degraded states are often unclear. In Canyonlands National Park on the Colorado Plateau of southeastern Utah, many degraded grasslands have not recovered structure and function >40 yr after release from livestock grazing pressure, necessitating active restoration. We hypothesized that multiple factors contribute to the persistent degraded state, including lack of seed availability, surficial soil-hydrological properties, and high levels of spatial connectivity (lack of perennial vegetation and other surface structure to retain water, litter, seed, and sediment). In combination with seeding and surface raking treatments, we tested the effect of small barrier structures (“ConMods”) designed to disrupt the loss of litter, seed and sediment in degraded soil patches within the park. Grass establishment was highest when all treatments (structures, seed addition, and soil disturbance) were combined, but only in the second year after installation, following favorable climatic conditions. We suggest that multiple limiting factors were ameliorated by treatments, including seed limitation and microsite availability, seed removal by harvester ants, and stressful abiotic conditions. Higher densities of grass seedlings on the north and east sides of barrier structures following the summer months suggest that structures may have functioned as artificial “nurse-plants”, sheltering seedlings from wind and radiation as well as accumulating wind-blown resources. Barrier structures increased the establishment of both native perennial grasses and exotic annuals, although there were species-specific differences in mortality related to spatial distribution of seedlings within barrier structures. The unique success of all treatments combined, and even then only under favorable climatic conditions and in certain soil patches, highlights that restoration success (and

  10. Fire frequency and tree canopy structure influence plant species diversity in a forest-grassland ecotone

    Science.gov (United States)

    David W. Peterson; Peter B. Reich

    2008-01-01

    Disturbances and environmental heterogeneity are two factors thought to influence plant species diversity, but their effects are still poorly understood in many ecosystems. We surveyed understory vegetation and measured tree canopy cover on permanent plots spanning an experimental fire frequency gradient to test fire frequency and tree canopy effects on plant species...

  11. Experimental Manipulation of Grassland Plant Diversity Induces Complex Shifts in Aboveground Arthropod Diversity

    Science.gov (United States)

    Hertzog, Lionel R.; Meyer, Sebastian T.; Weisser, Wolfgang W.; Ebeling, Anne

    2016-01-01

    Changes in producer diversity cause multiple changes in consumer communities through various mechanisms. However, past analyses investigating the relationship between plant diversity and arthropod consumers focused only on few aspects of arthropod diversity, e.g. species richness and abundance. Yet, shifts in understudied facets of arthropod diversity like relative abundances or species dominance may have strong effects on arthropod-mediated ecosystem functions. Here we analyze the relationship between plant species richness and arthropod diversity using four complementary diversity indices, namely: abundance, species richness, evenness (equitability of the abundance distribution) and dominance (relative abundance of the dominant species). Along an experimental gradient of plant species richness (1, 2, 4, 8, 16 and 60 plant species), we sampled herbivorous and carnivorous arthropods using pitfall traps and suction sampling during a whole vegetation period. We tested whether plant species richness affects consumer diversity directly (i), or indirectly through increased productivity (ii). Further, we tested the impact of plant community composition on arthropod diversity by testing for the effects of plant functional groups (iii). Abundance and species richness of both herbivores and carnivores increased with increasing plant species richness, but the underlying mechanisms differed between the two trophic groups. While higher species richness in herbivores was caused by an increase in resource diversity, carnivore richness was driven by plant productivity. Evenness of herbivore communities did not change along the gradient in plant species richness, whereas evenness of carnivores declined. The abundance of dominant herbivore species showed no response to changes in plant species richness, but the dominant carnivores were more abundant in species-rich plant communities. The functional composition of plant communities had small impacts on herbivore communities, whereas

  12. Experimental Manipulation of Grassland Plant Diversity Induces Complex Shifts in Aboveground Arthropod Diversity.

    Science.gov (United States)

    Hertzog, Lionel R; Meyer, Sebastian T; Weisser, Wolfgang W; Ebeling, Anne

    2016-01-01

    Changes in producer diversity cause multiple changes in consumer communities through various mechanisms. However, past analyses investigating the relationship between plant diversity and arthropod consumers focused only on few aspects of arthropod diversity, e.g. species richness and abundance. Yet, shifts in understudied facets of arthropod diversity like relative abundances or species dominance may have strong effects on arthropod-mediated ecosystem functions. Here we analyze the relationship between plant species richness and arthropod diversity using four complementary diversity indices, namely: abundance, species richness, evenness (equitability of the abundance distribution) and dominance (relative abundance of the dominant species). Along an experimental gradient of plant species richness (1, 2, 4, 8, 16 and 60 plant species), we sampled herbivorous and carnivorous arthropods using pitfall traps and suction sampling during a whole vegetation period. We tested whether plant species richness affects consumer diversity directly (i), or indirectly through increased productivity (ii). Further, we tested the impact of plant community composition on arthropod diversity by testing for the effects of plant functional groups (iii). Abundance and species richness of both herbivores and carnivores increased with increasing plant species richness, but the underlying mechanisms differed between the two trophic groups. While higher species richness in herbivores was caused by an increase in resource diversity, carnivore richness was driven by plant productivity. Evenness of herbivore communities did not change along the gradient in plant species richness, whereas evenness of carnivores declined. The abundance of dominant herbivore species showed no response to changes in plant species richness, but the dominant carnivores were more abundant in species-rich plant communities. The functional composition of plant communities had small impacts on herbivore communities, whereas

  13. Plant species diversity affects infiltration capacity in an experimental grassland through changes in soil properties

    NARCIS (Netherlands)

    Fischer, C.; Tischer, J.; Roscher, C.; Eisenhauer, N.; Ravenek, J.; Gleixner, G.; Attinger, S.; Jensen, B.; Kroon, de H.; Mommer, L.; Scheu, S.; Hildebrandt, A.

    2015-01-01

    Background and aims Soil hydraulic properties drive water distribution and availability in soil. There exists limited knowledge of how plant species diversity might influence soil hydraulic properties. Methods We quantified the change in infiltration capacity affected by soil structural variables

  14. Plant trait-based models identify direct and indirect effects of climate change on bundles of grassland ecosystem services.

    Science.gov (United States)

    Lamarque, Pénélope; Lavorel, Sandra; Mouchet, Maud; Quétier, Fabien

    2014-09-23

    Land use and climate change are primary causes of changes in the supply of ecosystem services (ESs). Although the consequences of climate change on ecosystem properties and associated services are well documented, the cascading impacts of climate change on ESs through changes in land use are largely overlooked. We present a trait-based framework based on an empirical model to elucidate how climate change affects tradeoffs among ESs. Using alternative scenarios for mountain grasslands, we predicted how direct effects of climate change on ecosystems and indirect effects through farmers' adaptations are likely to affect ES bundles through changes in plant functional properties. ES supply was overall more sensitive to climate than to induced management change, and ES bundles remained stable across scenarios. These responses largely reflected the restricted extent of management change in this constrained system, which was incorporated when scaling up plot level climate and management effects on ecosystem properties to the entire landscape. The trait-based approach revealed how the combination of common driving traits and common responses to changed fertility determined interactions and tradeoffs among ESs.

  15. The role of above-ground competition and nitrogen vs. phosphorus enrichment in seedling survival of common European plant species of semi-natural grasslands.

    Directory of Open Access Journals (Sweden)

    Tobias Ceulemans

    Full Text Available Anthropogenic activities have severely altered fluxes of nitrogen and phosphorus in ecosystems worldwide. In grasslands, subsequent negative effects are commonly attributed to competitive exclusion of plant species following increased above-ground biomass production. However, some studies have shown that this does not fully account for nutrient enrichment effects, questioning whether lowering competition by reducing grassland productivity through mowing or herbivory can mitigate the environmental impact of nutrient pollution. Furthermore, few studies so far discriminate between nitrogen and phosphorus pollution. We performed a full factorial experiment in greenhouse mesocosms combining nitrogen and phosphorus addition with two clipping regimes designed to relax above-ground competition. Next, we studied the survival and growth of seedlings of eight common European grassland species and found that five out of eight species showed higher survival under the clipping regime with the lowest above-ground competition. Phosphorus addition negatively affected seven plant species and nitrogen addition negatively affected four plant species. Importantly, the negative effects of nutrient addition and higher above-ground competition were independent of each other for all but one species. Our results suggest that at any given level of soil nutrients, relaxation of above-ground competition allows for higher seedling survival in grasslands. At the same time, even at low levels of above-ground competition, nutrient enrichment negatively affects survival as compared to nutrient-poor conditions. Therefore, although maintaining low above-ground competition appears essential for species' recruitment, for instance through mowing or herbivory, these management efforts are likely to be insufficient and we conclude that environmental policies aimed to reduce both excess nitrogen and particularly phosphorus inputs are also necessary.

  16. Altered Plant Litter and Microbial Composition Lead to Topsoil Organic Carbon Loss Over a Shrub-encroachment Gradient in an Inner Mongolia Grassland

    Science.gov (United States)

    Zhou, L.; Li, H.; Shen, H.; Xu, Y.; Wang, Y.; Xing, A.; Fang, J.

    2017-12-01

    Over the past 150 years, shrub encroachment has occurred in arid and semi-arid ecosystems resulting from climate change and increased human disturbance. Previous studies have revealed that shrub encroachment has substantial effects on habitat heterogeneity, aboveground biomass and bulk carbon content of grasslands, thereby affecting the regional carbon balance. Soil organic carbon (SOC) is mainly derived from aboveground litter, root litter and root exudates and is metabolized by microorganisms. The quality and quantity of plant litter together with soil microbial biomass are important drivers of SOC accumulation. However, the mechanisms regulating soil carbon accumulation by the shrub encroachment remain unclear and molecular evidence is particularly lacking. We use the data of the chemical composition of plant tissues and SOC, and the soil microbial communities to identify the effects of shrub encroachment on SOC accumulation in the top layer along a gradient of natural shrub cover in the grasslands of Inner Mongolia. Our finding indicates that nitrogen-rich legume-shrub encroachment led to soil carbon accumulation in the shrub patch, with more extensive carbon loss observed in the grassy matrix, which resulted in an overall carbon loss. In the pure grassland, a higher abundance of cutin and suberin and a lower concentration of free lipids were detected, suggesting the preservation of recalcitrant polymers derived from herb inputs. In the shrub-encroached grasslands, the labile shrub leaves did not decompose alone but were mixed with herb litter to promote the degradation of SOC via the priming of microbial activities. The SOC remained unchanged in the shrub patches with the increasing shrub cover, which might have been caused by the replacement of prior carbon decompositions with the fresh input of shrub leaves. Similarly, the SOC decreased significantly with increasing shrub cover in the grassy matrix, which likely resulted from insufficient fresh plant inputs

  17. Long-Term Overgrazing-Induced Memory Decreases Photosynthesis of Clonal Offspring in a Perennial Grassland Plant.

    Science.gov (United States)

    Ren, Weibo; Hu, Ningning; Hou, Xiangyang; Zhang, Jize; Guo, Huiqin; Liu, Zhiying; Kong, Lingqi; Wu, Zinian; Wang, Hui; Li, Xiliang

    2017-01-01

    Previous studies of transgenerational plasticity have demonstrated that long-term overgrazing experienced by Leymus chinensis , an ecologically dominant, rhizomatous grass species in eastern Eurasian temperate grassland, significantly affects its clonal growth in subsequent generations. However, there is a dearth of information on the reasons underlying this overgrazing-induced memory effect in plant morphological plasticity. We characterized the relationship between a dwarf phenotype and photosynthesis function decline of L. chinensis from the perspective of leaf photosynthesis by using both field measurement and rhizome buds culture cultivated in a greenhouse. Leaf photosynthetic functions (net photosynthetic rate, stomatal conductance, intercellular carbon dioxide concentration, and transpiration rate) were significantly decreased in smaller L. chinensis individuals that were induced to have a dwarf phenotype by being heavily grazed in the field. This decreased photosynthetic function was maintained a generation after greenhouse tests in which grazing was excluded. Both the response of L. chinensis morphological traits and photosynthetic functions in greenhouse were deceased relative to those in the field experiment. Further, there were significant decreases in leaf chlorophyll content and Rubisco enzyme activities of leaves between bud-cultured dwarf and non-dwarf L. chinensis in the greenhouse. Moreover, gene expression patterns showed that the bud-cultured dwarf L. chinensis significantly down-regulated (by 1.86- to 5.33-fold) a series of key genes that regulate photosynthetic efficiency, stomata opening, and chloroplast development compared with the non-dwarf L. chinensis . This is among the first studies revealing a linkage between long-term overgrazing affecting the transgenerational morphological plasticity of clonal plants and physiologically adaptive photosynthesis function. Overall, clonal transgenerational effects in L. chinensis phenotypic traits

  18. Long-Term Overgrazing-Induced Memory Decreases Photosynthesis of Clonal Offspring in a Perennial Grassland Plant

    Directory of Open Access Journals (Sweden)

    Xiangyang Hou

    2017-04-01

    Full Text Available Previous studies of transgenerational plasticity have demonstrated that long-term overgrazing experienced by Leymus chinensis, an ecologically dominant, rhizomatous grass species in eastern Eurasian temperate grassland, significantly affects its clonal growth in subsequent generations. However, there is a dearth of information on the reasons underlying this overgrazing-induced memory effect in plant morphological plasticity. We characterized the relationship between a dwarf phenotype and photosynthesis function decline of L. chinensis from the perspective of leaf photosynthesis by using both field measurement and rhizome buds culture cultivated in a greenhouse. Leaf photosynthetic functions (net photosynthetic rate, stomatal conductance, intercellular carbon dioxide concentration, and transpiration rate were significantly decreased in smaller L. chinensis individuals that were induced to have a dwarf phenotype by being heavily grazed in the field. This decreased photosynthetic function was maintained a generation after greenhouse tests in which grazing was excluded. Both the response of L. chinensis morphological traits and photosynthetic functions in greenhouse were deceased relative to those in the field experiment. Further, there were significant decreases in leaf chlorophyll content and Rubisco enzyme activities of leaves between bud-cultured dwarf and non-dwarf L. chinensis in the greenhouse. Moreover, gene expression patterns showed that the bud-cultured dwarf L. chinensis significantly down-regulated (by 1.86- to 5.33-fold a series of key genes that regulate photosynthetic efficiency, stomata opening, and chloroplast development compared with the non-dwarf L. chinensis. This is among the first studies revealing a linkage between long-term overgrazing affecting the transgenerational morphological plasticity of clonal plants and physiologically adaptive photosynthesis function. Overall, clonal transgenerational effects in L. chinensis

  19. Study of Plant Species Composition of Grasslands in Mugla Village Region (Western Rhodopes, South Bulgaria

    Directory of Open Access Journals (Sweden)

    Plamen S. Stoyanov

    2016-06-01

    Full Text Available The study presents data on the diversity of grass species in the region of the village of Mugla (the Western Rhodopes. One hundred forty-one species of higher plants belonging to 40families were registered. (Apiaceae, Aspleniaceae, Asteraceae, Boraginaceae, Brassicaceae,Campanulaceae, Caryophyllaceae, Cistaceae, Cyperaceae, Dipsacaceae, Equisetaceae, Ericaceae,Euphorbiaceae, Fabaceae, Gentianaceae, Geraniaceae, Gesneriaceae, Hypericaceae, Juncaceae,Lamiaceae, Lemnaceae, Liliaceae, Linaceae, Menyanthaceae, Oleacea, Onagraceae, Orchidaceae,Parnassiaceae, Plantaginaceae, Plumbaginaceae, Poaceae, Polygalaceae, Primulaceae,Ranunculaceae, Rosaceae, Rubiaceae, Saxifragaceae, Scrophulariaceae, Valerianaceae andViolaceae. Their conservation status was presented, as well as medicinal plants.

  20. Using plant functional traits to guide restoration: A case study in California coastal grassland

    DEFF Research Database (Denmark)

    Sandel, Brody Steven; Corbin, Jeffrey; Krupa, Monica

    2011-01-01

    Restoration ecology can benefit greatly from developments in trait-based ecology that enable improved predictions of how the composition of plant communities will respond to changes in environmental conditions. Plant functional traits can be used to guide the restoration of degraded habitats...... generally from the treatments. Carbon addition led to large intraspecific trait shifts, with individuals in C addition plots having smaller, denser leaves and shorter stature. Species' trait plasticity, however, was not related to the community composition response to C addition.   Our study indicates...

  1. Species richness of arbuscular mycorrhizal fungi: associations with grassland plant richness and biomass

    Czech Academy of Sciences Publication Activity Database

    Hiiesalu, Inga; Pärtel, M.; Davison, J.; Gerhold, P.; Metsis, M.; Moora, M.; Öpik, M.; Vasar, M.; Zobel, M.; Wilson, S. D.

    2014-01-01

    Roč. 203, č. 1 (2014), s. 233-244 ISSN 1469-8137 R&D Projects: GA MŠk EE2.3.30.0048 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : belowground plant richness * diversity * productivity Subject RIV: EH - Ecology, Behaviour Impact factor: 6.545, year: 2013

  2. Longterm changes in plant diversity of grasslands under agricultural and conservation management

    NARCIS (Netherlands)

    Snoo, de G.R.; Naus, N.; Verhulst, J.; Ruijven, van J.; Schaffers, A.P.

    2012-01-01

    Question In many industrialized countries biodiversity is declining. Although changes in species composition and species richness have been documented for many individual systems, little long-term research has been done on a regional scale. We compared the temporal patterns of plant diversity over

  3. Impact of Soil Warming on the Plant Metabolome of Icelandic Grasslands

    Science.gov (United States)

    Gargallo-Garriga, Albert; Ayala-Roque, Marta; Granda, Victor; Sigurdsson, Bjarni D.; Leblans, Niki I. W.; Oravec, Michal; Urban, Otmar; Janssens, Ivan A.

    2017-01-01

    Climate change is stronger at high than at temperate and tropical latitudes. The natural geothermal conditions in southern Iceland provide an opportunity to study the impact of warming on plants, because of the geothermal bedrock channels that induce stable gradients of soil temperature. We studied two valleys, one where such gradients have been present for centuries (long-term treatment), and another where new gradients were created in 2008 after a shallow crustal earthquake (short-term treatment). We studied the impact of soil warming (0 to +15 °C) on the foliar metabolomes of two common plant species of high northern latitudes: Agrostis capillaris, a monocotyledon grass; and Ranunculus acris, a dicotyledonous herb, and evaluated the dependence of shifts in their metabolomes on the length of the warming treatment. The two species responded differently to warming, depending on the length of exposure. The grass metabolome clearly shifted at the site of long-term warming, but the herb metabolome did not. The main up-regulated compounds at the highest temperatures at the long-term site were saccharides and amino acids, both involved in heat-shock metabolic pathways. Moreover, some secondary metabolites, such as phenolic acids and terpenes, associated with a wide array of stresses, were also up-regulated. Most current climatic models predict an increase in annual average temperature between 2–8 °C over land masses in the Arctic towards the end of this century. The metabolomes of A. capillaris and R. acris shifted abruptly and nonlinearly to soil warming >5 °C above the control temperature for the coming decades. These results thus suggest that a slight warming increase may not imply substantial changes in plant function, but if the temperature rises more than 5 °C, warming may end up triggering metabolic pathways associated with heat stress in some plant species currently dominant in this region. PMID:28832555

  4. Identification, collection and domestication of medicinal plants in ...

    African Journals Online (AJOL)

    Field studies were conducted to investigate the medicinal plants, through identification, collection and domestication of these plants in southeastern, Nigeria. Questionnaire, personal interview and review of available records show that out of forty-three plants about fifteen were undergoing domestication in the course of this ...

  5. Positive interactions between large herbivores and grasshoppers, and their consequences for grassland plant diversity.

    Science.gov (United States)

    Zhong, Zhiwei; Wang, Deli; Zhu, Hui; Wang, Ling; Feng, Chao; Wang, Zhongnan

    2014-04-01

    Although the influence of positive interactions on plant and sessile communities has been well documented, surprisingly little is known about their role in structuring terrestrial animal communities. We evaluated beneficial interactions between two distantly related herbivore taxa, large vertebrate grazers (sheep) and smaller insect grazers (grasshoppers), using a set of field experiments in eastern Eurasian steppe of China. Grazing by large herbivores caused significantly higher grasshopper density, and this pattern persisted until the end of the experiment. Grasshoppers, in turn, increased the foraging time of larger herbivores, but such response occurred only during the peak of growing season (August). These reciprocal interactions were driven by differential herbivore foraging preferences for plant resources; namely, large herbivores preferred Artemisia forbs, whereas grasshoppers preferred Leymus grass. The enhancement of grasshopper density in areas grazed by large herbivores likely resulted from the selective consumption of Artemisia forbs by vertebrate grazers, which may potentially improve the host finding of grasshoppers. Likewise, grasshoppers appeared to benefit large herbivores by decreasing the cover and density of the dominant grass Leymus chinensis, which hampers large herbivores' access to palatable forbs. Moreover, we found that large herbivores grazing alone may significantly decrease plant diversity, yet grasshoppers appeared to mediate such negative effects when they grazed with large herbivores. Our results suggest that the positive, reciprocal interactions in terrestrial herbivore communities may be more prevalent and complex than previously thought.

  6. [Energy accumulation and allocation of main plant populations in Aneurolepidium chinense grassland in Songnen Plain].

    Science.gov (United States)

    Qu, Guohui; Wen, Mingzhang; Guo, Jixun

    2003-05-01

    The calorific value of plants is dependent on their biological characteristics and energy-containing materials. The allocation of calorific value in different organs of Aneurolepidium chinese, Calamagrostic epigejos, Puccinellia tenuiflora and Chloris virgata was inflorescence > leaf > stem > dead standing. The seasonal dynamics of standing crop energy of aboveground part of four plant populations showed single-peak curve, and the energy production was Aneurolepidium chinense > Calamagrostic epigejos > Chloris virgata > Puccinellia tenuiflora. Energy increasing rate showed double-peak curve, with the first peak at heading stage and the second peak at maturing stage of seeds. Energy increasing rate was negative at the final stage of growth. The horizontal distribution of energy of aboveground part was that the allocation ratio of different organs at different growth stages was different. There existed a similar trend for vertical distribution of energy among four plant populations, i.e., was the vertical distribution of energy of aboveground part showed a tower shape, with the maximum value in 10-30 cm height. The vertical distribution of energy of underground part showed an inverted tower shape from soil surface to deeper layer, with the maximum value in 0-10 cm depth. The standing crop energy of underground part was about 3-4 times than that of aboveground part.

  7. Plant assemblage composition and soil P concentration differentially affect communities of AM and total fungi in a semi-arid grassland.

    Science.gov (United States)

    Klabi, Rim; Bell, Terrence H; Hamel, Chantal; Iwaasa, Alan; Schellenberg, Mike; Raies, Aly; St-Arnaud, Marc

    2015-01-01

    Adding inorganic P- and N-fixing legumes to semi-arid grasslands can increase forage yield, but soil nutrient concentrations and plant cover may also interact to modify soil fungal populations, impacting short- and long-term forage production. We tested the effect of plant assemblage (seven native grasses, seven native grasses + the domesticated N-fixing legume Medicago sativa, seven native grasses + the native N-fixing legume Dalea purpurea or the introduced grass Bromus biebersteinii + M. sativa) and soil P concentration (addition of 0 or 200 P2O5 kg ha(-1) at sowing) on the diversity and community structure of arbuscular mycorrhizal (AM) fungi and total fungi over two consecutive years, using 454-pyrosequencing of 18S rDNA and ITS amplicons. Treatment effects were stronger in the wet year (2008) than the dry year (2009). The presence of an N-fixing legume with native grasses generally increased AM fungal diversity, while the interaction between soil P concentration and plant assemblage modified total fungal community structure in 2008. Excluding interannual variations, which are likely driven by moisture and plant productivity, AM fungal communities in semi-arid grasslands appear to be primarily affected by plant assemblage composition, while the composition of other fungi is more closely linked to soil P. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Native-plant amendments and topsoil addition enhance soil function in post-mining arid grasslands.

    Science.gov (United States)

    Kneller, Tayla; Harris, Richard J; Bateman, Amber; Muñoz-Rojas, Miriam

    2018-04-15

    One of the most critical challenges faced in restoration of disturbed arid lands is the limited availability of topsoil. In post-mining restoration, alternative soil substrates such as mine waste could be an adequate growth media to alleviate the topsoil deficit, but these materials often lack appropriate soil characteristics to support the development and survival of seedlings. Thus, addition of exogenous organic matter may be essential to enhance plant survival and soil function. Here, we present a case study in the arid Pilbara region (north-west Western Australia), a resource-rich area subject to intensive mining activities. The main objective of our study was to assess the effects of different restoration techniques such as soil reconstruction by blending available soil materials, sowing different compositions of plant species, and addition of a locally abundant native soil organic amendment (Triodia pungens biomass) on: (i) seedling recruitment and growth of Triodia wiseana, a dominant grass in Australian arid ecosystems, and (ii) soil chemical, physical, and biological characteristics of reconstructed soils, including microbial activity, total organic C, total N, and C and N mineralisation. The study was conducted in a 12-month multifactorial microcosms setting in a controlled environment. Our results showed that the amendment increased C and N contents of re-made soils, but these values were still lower than those obtained in the topsoil. High microbial activity and C mineralisation rates were found in the amended waste that contrasted the low N mineralisation but this did not translate into improved emergence or survival of T. wiseana. These results suggest a short- or medium-term soil N immobilisation caused by negative priming effect of fresh un-composted amendment on microbial communities. We found similar growth and survival rates of T. wiseana in topsoil and a blend of topsoil and waste (50:50) which highlights the importance of topsoil, even in a

  9. Effects of seed size and habitat on recruitment patterns in grassland and forest plants

    OpenAIRE

    Lönnberg, Karin

    2012-01-01

    A trade-off between seed size and seed number is central in seed ecology, and has been suggested to be related to a trade-off between competition and colonization, as well as to a trade-off between stress tolerance and fecundity. Large seeds endure hazards during establishment, such as shading, drought, litter coverage and competition from other plants, better than do small seeds, due to a larger amount of stored resources in the seed. Small seeds, however, are numerous and small-seeded speci...

  10. How do earthworms, soil texture and plant composition affect infiltration along an experimental plant diversity gradient in grassland?

    Science.gov (United States)

    Fischer, Christine; Roscher, Christiane; Jensen, Britta; Eisenhauer, Nico; Baade, Jussi; Attinger, Sabine; Scheu, Stefan; Weisser, Wolfgang W; Schumacher, Jens; Hildebrandt, Anke

    2014-01-01

    Infiltration is a key process in determining the water balance, but so far effects of earthworms, soil texture, plant species diversity and their interaction on infiltration capacity have not been studied. We measured infiltration capacity in subplots with ambient and reduced earthworm density nested in plots of different plant species (1, 4, and 16 species) and plant functional group richness and composition (1 to 4 groups; legumes, grasses, small herbs, tall herbs). In summer, earthworm presence significantly increased infiltration, whereas in fall effects of grasses and legumes on infiltration were due to plant-mediated changes in earthworm biomass. Effects of grasses and legumes on infiltration even reversed effects of texture. We propose two pathways: (i) direct, probably by modifying the pore spectrum and (ii) indirect, by enhancing or suppressing earthworm biomass, which in turn influenced infiltration capacity due to change in burrowing activity of earthworms. Overall, the results suggest that spatial and temporal variations in soil hydraulic properties can be explained by biotic processes, especially the presence of certain plant functional groups affecting earthworm biomass, while soil texture had no significant effect. Therefore biotic parameters should be taken into account in hydrological applications.

  11. How do earthworms, soil texture and plant composition affect infiltration along an experimental plant diversity gradient in grassland?

    Directory of Open Access Journals (Sweden)

    Christine Fischer

    Full Text Available BACKGROUND: Infiltration is a key process in determining the water balance, but so far effects of earthworms, soil texture, plant species diversity and their interaction on infiltration capacity have not been studied. METHODOLOGY/PRINCIPAL FINDINGS: We measured infiltration capacity in subplots with ambient and reduced earthworm density nested in plots of different plant species (1, 4, and 16 species and plant functional group richness and composition (1 to 4 groups; legumes, grasses, small herbs, tall herbs. In summer, earthworm presence significantly increased infiltration, whereas in fall effects of grasses and legumes on infiltration were due to plant-mediated changes in earthworm biomass. Effects of grasses and legumes on infiltration even reversed effects of texture. We propose two pathways: (i direct, probably by modifying the pore spectrum and (ii indirect, by enhancing or suppressing earthworm biomass, which in turn influenced infiltration capacity due to change in burrowing activity of earthworms. CONCLUSIONS/SIGNIFICANCE: Overall, the results suggest that spatial and temporal variations in soil hydraulic properties can be explained by biotic processes, especially the presence of certain plant functional groups affecting earthworm biomass, while soil texture had no significant effect. Therefore biotic parameters should be taken into account in hydrological applications.

  12. Code for plant identification (KKS) key in PC version

    International Nuclear Information System (INIS)

    Pannenbaecker, K.

    1991-01-01

    The plant identification system (KKS) as a common development of german plant operators, erection firms and also power plant oriented organisations have decisively influenced the technical-organizing activities of planning and erections as operations and maintenance of all kind of power plants. Fundamentals are three key parts, operation, armatures and function keys. Their management and application is executed by a plantidentification-key code in a PC version, which is briefly described in this report. (orig.) [de

  13. Plant Identification Characteristics for Deciduous Trees & Shrubs. Lesson Plans.

    Science.gov (United States)

    Burkholder, Kathy

    This manual contains a group of lesson plans designed for use with a slide series (not included here). Its purpose is to introduce students to the basic concepts and terminology used in the identification of deciduous trees and shrubs. The manual is composed of 12 lesson plans. The first lesson is an introduction to plant identification. The…

  14. Density-dependency and plant-soil feedback: former plant abundance influences competitive interactions between two grassland plant species through plant-soil feedbacks

    NARCIS (Netherlands)

    Xue, W.; Bezemer, T.M.; Berendse, Frank

    2018-01-01

    Backgrounds and aims Negative plant-soil feedbacks (PSFs) are thought to promote species coexistence, but most evidence is derived from theoretical models and data from plant monoculture experiments. Methods We grew Anthoxanthum odoratum and Centaurea jacea in field plots in monocultures and in

  15. The structural and functional connectivity of the grassland plant Lychnis flos-cuculi

    Science.gov (United States)

    Aavik, T; Holderegger, R; Bolliger, J

    2014-01-01

    Understanding the relationship between structural and functional connectivity is essential for successful restoration and conservation management, particularly in intensely managed agricultural landscapes. We evaluated the relationship between structural and functional connectivity of the wetland plant Lychnis flos-cuculi in a fragmented agricultural landscape using landscape genetic and network approaches. First, we studied the effect of structural connectivity, such as geographic distance and various landscape elements (forest, agricultural land, settlements and ditch verges), on gene flow among populations as a measurement of functional connectivity. Second, we examined the effect of structural graph-theoretic connectivity measures on gene flow among populations and on genetic diversity within populations of L. flos-cuculi. Among landscape elements, forests hindered gene flow in L. flos-cuculi, whereas gene flow was independent of geographic distance. Among the structural graph-theoretic connectivity variables, only intrapopulation connectivity, which was based on population size, had a significant positive effect on gene flow, that is, more gene flow took place among larger populations. Unexpectedly, interpopulation connectivity of populations, which takes into account the spatial location and distance among populations, did not influence gene flow in L. flos-cuculi. However, higher observed heterozygosity and lower inbreeding was observed in populations characterised by higher structural interpopulation connectivity. This finding shows that a spatially coherent network of populations is significant for maintaining the genetic diversity of populations. Nevertheless, lack of significant relationships between gene flow and most of the structural connectivity measures suggests that structural connectivity does not necessarily correspond to functional connectivity. PMID:24253937

  16. Assessing the biophysical naturalness of grassland in eastern North Dakota with hyperspectral imagery

    Science.gov (United States)

    Zhou, Qiang

    Over the past two decades, non-native species within grassland communities have quickly developed due to human migration and commerce. Invasive species like Smooth Brome grass (Bromus inermis) and Kentucky Blue Grass (Poa pratensis), seriously threaten conservation of native grasslands. This study aims to discriminate between native grasslands and planted hayfields and conservation areas dominated by introduced grasses using hyperspectral imagery. Hyperspectral imageries from the Hyperion sensor on EO-1 were acquired in late spring and late summer on 2009 and 2010. Field spectra for widely distributed species as well as smooth brome grass and Kentucky blue grass were collected from the study sites throughout the growing season. Imagery was processed with an unmixing algorithm to estimate fractional cover of green and dry vegetation and bare soil. As the spectrum is significantly different through growing season, spectral libraries for the most common species are then built for both the early growing season and late growing season. After testing multiple methods, the Adaptive Coherence Estimator (ACE) was used for spectral matching analysis between the imagery and spectral libraries. Due in part to spectral similarity among key species, the results of spectral matching analysis were not definitive. Additional indexes, "Level of Dominance" and "Band variance", were calculated to measure the predominance of spectral signatures in any area. A Texture co-occurrence analysis was also performed on both "Level of Dominance" and "Band variance" indexes to extract spatial characteristics. The results suggest that compared with disturbed area, native prairie tend to have generally lower "Level of Dominance" and "Band variance" as well as lower spatial dissimilarity. A final decision tree model was created to predict presence of native or introduced grassland. The model was more effective for identification of Mixed Native Grassland than for grassland dominated by a single

  17. Identification of plant defence regulators through transcriptional ...

    Indian Academy of Sciences (India)

    2015-02-04

    Feb 4, 2015 ... defence-related genes also supports constitutive activation of defence in cdd1. We screened T-DNA ..... identified through this work as novel plant defence regu- ... to drought stress than untransformed plants (Lee et al. 2012).

  18. The relationship between plant species richness and soil pH vanishes with increasing aridity across Eurasian dry grasslands

    Czech Academy of Sciences Publication Activity Database

    Palpurina, S.; Wagner, V.; von Wehrden, H.; Hájek, M.; Horsák, M.; Brinkert, A.; Hölzel, N.; Wesche, K.; Kamp, J.; Hájková, Petra; Danihelka, Jiří; Lustyk, P.; Merunková, K.; Preislerová, Z.; Kočí, M.; Kubešová, S.; Cherosov, M. M.; Ermakov, N.; German, D.; Gogoleva, P. A.; Lashchinsky, N.; Martynenko, V. B.; Chytrý, M.

    2017-01-01

    Roč. 26, č. 4 (2017), s. 425-434 ISSN 1466-822X Institutional support: RVO:67985939 Keywords : diversity-environment relationship * dry grassland * precipitation * soil pH Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 6.045, year: 2016

  19. An Interactive Multimedia Dichotomous Key for Teaching Plant Identification

    Science.gov (United States)

    Jacquemart, Anne-Laure; Lhoir, Pierre; Binard, Fabian; Descamps, Charlotte

    2016-01-01

    Teaching plant identification includes demonstrating how to use dichotomous keys; this requires knowledge of numerous botanical terms and can be challenging, confusing and frustrating for students. Here, we developed a multimedia tool to help students (1) learn botanical terms, (2) practice, train and test their knowledge of plant identification…

  20. Patterns of plant diversity loss and species turnover resulting from land abandonment and intensification in semi-natural grasslands.

    Science.gov (United States)

    Uchida, Kei; Koyanagi, Tomoyo F; Matsumura, Toshikazu; Koyama, Asuka

    2018-07-15

    Land-use changes cause biodiversity loss in semi-natural ecosystems worldwide. Biotic homogenization has led to biodiversity loss, mainly through declines in species composition turnover. Elucidating patterns of turnover in species composition could enhance our understanding of how anthropogenic activities affect community assembly. Here, we focused on whether the decreasing patterns in plant diversity and turnover of species composition resulting from land-use change vary in two regions. We estimated the species diversity and composition of semi-natural grasslands surrounding paddy fields in satoyama landscapes. We examined the differences in species diversity and composition across three land-use types (abandoned, traditional, and intensified) in two regions (Hyogo and Niigata Prefectures, Japan), which were characterized by different climatic conditions. We then assessed alpha-, beta-, and gamma-diversity to compare the patterns of diversity losses in the two regions as a result of land-use changes. In each region, gamma-diversity was consistently higher in the traditional sites compared to abandoned or intensified sites. The analyses revealed that most of the beta-diversity in traditional sites differed significantly from those of abandoned and intensified sites in both regions. However, the beta-diversity of total and perennial species did not differ between traditional and abandoned sites in the Hyogo region. We noted that the beta-diversity of total and perennial species in intensified sites was much lower than that in the traditional sites of the Niigata region. Overall, the patterns of alpha- and gamma-diversity loss were similar in both study regions. Although the biotic homogenization was caused by intensified land-use in the Niigata region, this hypothesis did not completely explain the loss of biodiversity in the abandoned sites in the Hyogo region. The present study contributes to the growing body of work investigating changes in biodiversity as a

  1. Are there consistent grazing indicators in Drylands? Testing plant functional types of various complexity in South Africa's Grassland and Savanna Biomes.

    Directory of Open Access Journals (Sweden)

    Anja Linstädter

    Full Text Available Despite our growing knowledge on plants' functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa's grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs. Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses and two-trait PFTs (e.g. perennial grasses performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may

  2. Are there consistent grazing indicators in Drylands? Testing plant functional types of various complexity in South Africa's Grassland and Savanna Biomes.

    Science.gov (United States)

    Linstädter, Anja; Schellberg, Jürgen; Brüser, Katharina; Moreno García, Cristian A; Oomen, Roelof J; du Preez, Chris C; Ruppert, Jan C; Ewert, Frank

    2014-01-01

    Despite our growing knowledge on plants' functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs) with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa's grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs). Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses) and two-trait PFTs (e.g. perennial grasses) performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold) had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may also be useful

  3. Identification of plant defence regulators through transcriptional ...

    Indian Academy of Sciences (India)

    ... of 4- week-old soil grown plants of Col-0 and T-DNA insertion mutant line of At2g19810 (SALK_151571). ... repeated at least twice with similar results (hpi – hours post inoculation). .... work of systemic acquired resistance in plants.

  4. Are There Consistent Grazing Indicators in Drylands? Testing Plant Functional Types of Various Complexity in South Africa’s Grassland and Savanna Biomes

    Science.gov (United States)

    Linstädter, Anja; Schellberg, Jürgen; Brüser, Katharina; Moreno García, Cristian A.; Oomen, Roelof J.; du Preez, Chris C.; Ruppert, Jan C.; Ewert, Frank

    2014-01-01

    Despite our growing knowledge on plants’ functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs) with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa’s grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs). Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses) and two-trait PFTs (e.g. perennial grasses) performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold) had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may also be

  5. Deep Learning for Plant Identification in Natural Environment.

    Science.gov (United States)

    Sun, Yu; Liu, Yuan; Wang, Guan; Zhang, Haiyan

    2017-01-01

    Plant image identification has become an interdisciplinary focus in both botanical taxonomy and computer vision. The first plant image dataset collected by mobile phone in natural scene is presented, which contains 10,000 images of 100 ornamental plant species in Beijing Forestry University campus. A 26-layer deep learning model consisting of 8 residual building blocks is designed for large-scale plant classification in natural environment. The proposed model achieves a recognition rate of 91.78% on the BJFU100 dataset, demonstrating that deep learning is a promising technology for smart forestry.

  6. Deep Learning for Plant Identification in Natural Environment

    Directory of Open Access Journals (Sweden)

    Yu Sun

    2017-01-01

    Full Text Available Plant image identification has become an interdisciplinary focus in both botanical taxonomy and computer vision. The first plant image dataset collected by mobile phone in natural scene is presented, which contains 10,000 images of 100 ornamental plant species in Beijing Forestry University campus. A 26-layer deep learning model consisting of 8 residual building blocks is designed for large-scale plant classification in natural environment. The proposed model achieves a recognition rate of 91.78% on the BJFU100 dataset, demonstrating that deep learning is a promising technology for smart forestry.

  7. Negative and positive interactions among plants: effects of competitors and litter on seedling emergence and growth of forest and grassland species.

    Science.gov (United States)

    Loydi, A; Donath, T W; Otte, A; Eckstein, R L

    2015-05-01

    Living plant neighbours, but also their dead aboveground remains (i.e. litter), may individually exert negative or positive effects on plant recruitment. Although living plants and litter co-occur in most ecosystems, few studies have addressed their combined effects, and conclusions are ambivalent. Therefore, we examined the response in terms of seedling emergence and growth of herbaceous grassland and forest species to different litter types and amounts and the presence of competitors. We conducted a pot experiment testing the effects of litter type (grass, oak), litter amount (low, medium, high) and interspecific competition (presence or absence of four Festuca arundinacea individuals) on seedling emergence and biomass of four congeneric pairs of hemicryptophytes from two habitat types (woodland, grassland). Interactions between litter and competition were weak. Litter presence increased competitor biomass. It also had positive effects on seedling emergence at low litter amounts and negative effects at high litter amounts, while competition had no effect on seedling emergence. Seedling biomass was negatively affected by the presence of competitors, and this effect was stronger in combination with high amounts of litter. Litter affected seedling emergence while competition determined the biomass of the emerged individuals, both affecting early stages of seedling recruitment. High litter accumulation also reduced seedling biomass, but this effect seemed to be additive to competitor effects. This suggests that live and dead plant mass can affect species recruitment in natural systems, but the mechanisms by which they operate and their timing differ. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  8. Interval Continuous Plant Identification from Value Sets

    Directory of Open Access Journals (Sweden)

    R. Hernández

    2012-01-01

    Full Text Available This paper shows how to obtain the values of the numerator and denominator Kharitonov polynomials of an interval plant from its value set at a given frequency. Moreover, it is proven that given a value set, all the assigned polynomials of the vertices can be determined if and only if there is a complete edge or a complete arc lying on a quadrant. This algorithm is nonconservative in the sense that if the value-set boundary of an interval plant is exactly known, and particularly its vertices, then the Kharitonov rectangles are exactly those used to obtain these value sets.

  9. Plant Species Identification by Bi-channel Deep Convolutional Networks

    Science.gov (United States)

    He, Guiqing; Xia, Zhaoqiang; Zhang, Qiqi; Zhang, Haixi; Fan, Jianping

    2018-04-01

    Plant species identification achieves much attention recently as it has potential application in the environmental protection and human life. Although deep learning techniques can be directly applied for plant species identification, it still needs to be designed for this specific task to obtain the state-of-art performance. In this paper, a bi-channel deep learning framework is developed for identifying plant species. In the framework, two different sub-networks are fine-tuned over their pretrained models respectively. And then a stacking layer is used to fuse the output of two different sub-networks. We construct a plant dataset of Orchidaceae family for algorithm evaluation. Our experimental results have demonstrated that our bi-channel deep network can achieve very competitive performance on accuracy rates compared to the existing deep learning algorithm.

  10. Plants diversity and phytoaccumulators identification on the ...

    African Journals Online (AJOL)

    The dominant taxa on the old waste dumpsite having an average density superior to 5 plants/m2 and occurring less frequently on the control site were Alternanthera sessilis, Amaranthus spinosus, Cyperus rotundus, Cyperus iria, Eleusine indica, Euphorbia glomerifera, Ipomoea triloba, Portulaca oleracea and Trianthema ...

  11. Plants diversity and phytoaccumulators identification on the ...

    African Journals Online (AJOL)

    MESSOU AMAN

    2004) and depend on metals mobility, utilization by organisms or ... if they are consumed, because of the toxicity of some metals to ... Ellis and Salt, 2003; Pillay et al., 2003). Industrial .... (Pb), iron (Fe), and copper (Cu) were respectively of 250, 50, 5, ...... bioremediation and mechanisms of heavy metals tolerance of plants:.

  12. Distribution, species diversity and composition of plant communities in relation to various affecting factors in an alpine grassland at Bandipora, Kashmir

    International Nuclear Information System (INIS)

    Dad, J. M.

    2016-01-01

    This study provides a broad understanding of vascular plant richness and community structure of mountain grassland (Matri) at Bandipora, Kashmir and links it various environmental variables. Employing a stratified sampling design, six sites were selected wherein vegetation was sampled by placing quadrats (n=210). Elucidating an important effect of topography and anthropic pressure, numerical classification TWINSPAN segregated the quadrats into seven community types. Contrary to species rich communities which showed an explicit composition and localized distribution, the other communities depicted a vague composition and stretched unevenly between the lower and middle altitudes. Using canonical correspondence analysis (CCA), elevation and disturbance were found as most influencing factors whereas steepness of slope, organic carbon, soil reaction (pH) and soil salinity (electrical conductivity) were other important factors. Indices of diversity measured at two measurement scales varied differently between communities and at a macro scale (site level) highest values were recorded in least disturbed communities. However, on a micro scale (quadrat level) the indices behaved differently. For effective conservation of these species rich grasslands, acknowledging the local level variability in vegetation structure is all but crucial. (author)

  13. Improving ITS sequence data for identification of plant pathogenic fungi

    Science.gov (United States)

    R. Henrik Nilsson; Kevin D. Hyde; Julia Pawłowska; Martin Ryberg; Leho Tedersoo; Anders Bjørnsgard Aas; Siti A. Alias; Artur Alves; Cajsa Lisa Anderson; Alexandre Antonelli; A. Elizabeth Arnold; Barbara Bahnmann; Mohammad Bahram; Johan Bengtsson-Palme; Anna Berlin; Sara Branco; Putarak Chomnunti; Asha Dissanayake; Rein Drenkhan; Hanna Friberg; Tobias Guldberg Frøslev; Bettina Halwachs; Martin Hartmann; Beatrice Henricot; Ruvishika Jayawardena; Ari Jumpponen; Håvard Kauserud; Sonja Koskela; Tomasz Kulik; Kare Liimatainen; Björn D. Lindahl; Daniel Lindner; Jian-Kui Liu; Sajeewa Maharachchikumbura; Dimuthu Manamgoda; Svante Martinsson; Maria Alice Neves; Tuula Niskanen; Stephan Nylinder; Olinto Liparini Pereira; Danilo Batista Pinho; Teresita M. Porter; Valentin Queloz; Taavi Riit; Marisol Sánchez-García; Filipe de Sousa; Emil Stefańczyk; Mariusz Tadych; Susumu Takamatsu; Qing Tian; Dhanushka Udayanga; Martin Unterseher; Zheng Wang; Saowanee Wikee; Jiye Yan; Ellen Larsson; Karl-Henrik Larsson; Urmas Kõljalg; Kessy Abarenkov

    2014-01-01

    Plant pathogenic fungi are a large and diverse assemblage of eukaryotes with substantial impacts on natural ecosystems and human endeavours. These taxa often have complex and poorly understood life cycles, lack observable, discriminatory morphological characters, and may not be amenable to in vitro culturing. As a result, species identification is frequently difficult...

  14. Rapid identification of the medicinal plant Taraxacum formosanum ...

    African Journals Online (AJOL)

    Original identification of medicinal plants is essential for quality control. In this study, the internal transcribed spacer 2 (ITS2) nuclear ribosomal DNA served as a DNA barcode and was amplified by allele-specific PCR. This approach was exploited to differentiate Taraxacum formosanum from five related adulterants. Using a ...

  15. Baboquivari Mountain plants: Identification, ecology, and ethnobotany [Book Review

    Science.gov (United States)

    Rosemary L. Pendleton

    2011-01-01

    The Sky Islands of southern Arizona and northwestern Mexico make up a region that is rich, both biologically and culturally. These isolated mountain ranges, separated by desert "seas," contain a unique and diverse flora and have long been home to indigenous peoples of the southwestern US. This book, Baboquivari Mountain Plants: Identification, Ecology, and...

  16. Meta-scale mountain grassland observatories uncover commonalities as well as specific interactions among plant and non-rhizosphere soil bacterial communities.

    Science.gov (United States)

    Yashiro, Erika; Pinto-Figueroa, Eric; Buri, Aline; Spangenberg, Jorge E; Adatte, Thierry; Niculita-Hirzel, Helene; Guisan, Antoine; van der Meer, Jan Roelof

    2018-04-10

    Interactions between plants and bacteria in the non-rhizosphere soil are rarely assessed, because they are less direct and easily masked by confounding environmental factors. By studying plant vegetation alliances and soil bacterial community co-patterning in grassland soils in 100 sites across a heterogeneous mountain landscape in the western Swiss Alps, we obtained sufficient statistical power to disentangle common co-occurrences and weaker specific interactions. Plant alliances and soil bacterial communities tended to be synchronized in community turnover across the landscape, largely driven by common underlying environmental factors, such as soil pH or elevation. Certain alliances occurring in distinct, local, environmental conditions were characterized by co-occurring specialist plant and bacterial species, such as the Nardus stricta and Thermogemmatisporaceae. In contrast, some generalist taxa, like Anthoxanthum odoratum and 19 Acidobacteria species, spanned across multiple vegetation alliances. Meta-scale analyses of soil bacterial community composition and vegetation surveys, complemented with local edaphic measurements, can thus prove useful to identify the various types of plant-bacteria interactions and the environments in which they occur.

  17. Ecological analysis of plant cover of the permanent grassland ecosystem located in the vicinity of Novi Kneževac, Serbia

    Directory of Open Access Journals (Sweden)

    Knežević Aleksa

    2012-01-01

    Full Text Available A total of 205 taxa and stands of 12 plant communities were found to comprise the plant cover of the permanent grassland on the solonetz and solonchakic solonetz soils located in the vicinity of the town of Novi Kneževac (Vojvodina Province, Serbia. The registered taxa included 177 plant species, six subspecies, eight varieties, 13 forms and one lusus. The ecological analysis of the flora involved 191 taxa. That group consisted of 177 species, six subspecies, three varieties and five forms. The three varieties, Aster tripolium L. var. pannonicus ( Jacq. Beck, Chenopodium rubrum L. subsp. botryoides Sm. var. crassifolium (Hornem Kov. and Sonchus arvensis L. var. uliginosus (M.B. Grec. were used for analysis because their higher taxonomic categories were not recorded in the studied flora. The five forms, Aster sedifolius L. f. subsquamosus Soy, Bromus commutatus Schrad. f. violaceus Podp., Mentha aquatica L. f. erromera Top., Poa bulbosa L. f. vivipara Koel. and Scleranthus annus L. f. minimus Schur., were used for the same reason. The ecological analysis encompassed stands of all 12 recorded communities, i.e. ass. Scirpo-Phragmitetum W. Koch 1926, ass. Bolboschoenetum maritimi continentale Soy (1927 1957, ass. Acorelletum pannonici Soy (1939 1947, ass. Puccinelletum limosae (Rapcs. 1927 Soy 1930, ass. Pholiuro-Plantaginetum tenuiflorae (Rapcs. 1927 Wendel. 1943, ass. Hordeetum histricis (Soy 1933 Wendel. 1943, ass. Camphorosmetum annuae (Rapcs. 1916 Soy 1933 corr. Soy 1938, ass. Agrostio-Alopecuretum pratensis Soy (1933 1947, ass. Agrostio-Eleochariti-Alopecuretu geniculati (Magyar1928 Soy (1939 1947, ass. Artemisio-Festucetum pseudovinae (Magyar 1928 Soy 1945, ass. Achilleo-Festucetum pseudovinae (Magyar 1928 Soy 1945 and ass. Festuco-Andropogonetum ischaemi Vučk. 1985. The ecological analysis of the plant cover indicated that halophytes made 30.37% of the flora of the permanent grassland near the town of Novi Kneževac, and that the stands of

  18. Does interspecific competition alter effects of early season ozone exposure on plants from wet grasslands? Results of a three-year experiment in open-top chambers.

    Science.gov (United States)

    Tonneijck, A E G; Franzaring, J; Brouwer, G; Metselaar, K; Dueck, Th A

    2004-09-01

    Chronic effects of ozone on wet grassland species early in the growing season might be altered by interspecific competition. Individual plants of Holcus lanatus, Lychnis flos-cuculi, Molinia caerulea and Plantago lanceolata were grown in monocultures and in mixed cultures with Agrostis capillaris. Mesocosms were exposed to charcoal-filtered air plus 25 nl l(-1) ozone (CF+25), non-filtered air (NF), non-filtered air plus 25 nl l(-1) ozone (NF+25) and non-filtered air plus 50 nl l(-1) ozone (NF+50) early in the growing seasons of 2000 through 2002. Ozone-enhanced senescence and visible foliar injury were recorded on some of the target plants in the first year only. Ozone effects on biomass production were minimal and plant response to ozone did not differ between monocultures and mixed cultures. After three years, above-ground biomass of the plants in mixed culture compared to monocultures was three times greater for H. lanatus and two to four times smaller for the other species.

  19. Does interspecific competition alter effects of early season ozone exposure on plants from wet grasslands? Results of a three-year experiment in open-top chambers

    Energy Technology Data Exchange (ETDEWEB)

    Tonneijck, A.E.G.; Franzaring, J.; Brouwer, G.; Metselaar, K.; Dueck, Th.A

    2004-09-01

    Chronic effects of ozone on wet grassland species early in the growing season might be altered by interspecific competition. Individual plants of Holcus lanatus, Lychnis flos-cuculi, Molinia caerulea and Plantago lanceolata were grown in monocultures and in mixed cultures with Agrostis capillaris. Mesocosms were exposed to charcoal-filtered air plus 25 nl l{sup -1} ozone (CF + 25), non-filtered air (NF), non-filtered air plus 25 nl l{sup -1} ozone (NF + 25) and non-filtered air plus 50 nl l{sup -1} ozone (NF + 50) early in the growing seasons of 2000 through 2002. Ozone-enhanced senescence and visible foliar injury were recorded on some of the target plants in the first year only. Ozone effects on biomass production were minimal and plant response to ozone did not differ between monocultures and mixed cultures. After three years, above-ground biomass of the plants in mixed culture compared to monocultures was three times greater for H. lanatus and two to four times smaller for the other species.

  20. Does interspecific competition alter effects of early season ozone exposure on plants from wet grasslands? Results of a three-year experiment in open-top chambers

    International Nuclear Information System (INIS)

    Tonneijck, A.E.G.; Franzaring, J.; Brouwer, G.; Metselaar, K.; Dueck, Th.A.

    2004-01-01

    Chronic effects of ozone on wet grassland species early in the growing season might be altered by interspecific competition. Individual plants of Holcus lanatus, Lychnis flos-cuculi, Molinia caerulea and Plantago lanceolata were grown in monocultures and in mixed cultures with Agrostis capillaris. Mesocosms were exposed to charcoal-filtered air plus 25 nl l -1 ozone (CF + 25), non-filtered air (NF), non-filtered air plus 25 nl l -1 ozone (NF + 25) and non-filtered air plus 50 nl l -1 ozone (NF + 50) early in the growing seasons of 2000 through 2002. Ozone-enhanced senescence and visible foliar injury were recorded on some of the target plants in the first year only. Ozone effects on biomass production were minimal and plant response to ozone did not differ between monocultures and mixed cultures. After three years, above-ground biomass of the plants in mixed culture compared to monocultures was three times greater for H. lanatus and two to four times smaller for the other species

  1. Soil environmental conditions and microbial build-up mediate the effect of plant diversity on soil nitrifying and denitrifying enzyme activities in temperate grasslands.

    Directory of Open Access Journals (Sweden)

    Xavier Le Roux

    Full Text Available Random reductions in plant diversity can affect ecosystem functioning, but it is still unclear which components of plant diversity (species number - namely richness, presence of particular plant functional groups, or particular combinations of these and associated biotic and abiotic drivers explain the observed relationships, particularly for soil processes. We assembled grassland communities including 1 to 16 plant species with a factorial separation of the effects of richness and functional group composition to analyze how plant diversity components influence soil nitrifying and denitrifying enzyme activities (NEA and DEA, respectively, the abundance of nitrifiers (bacterial and archaeal amoA gene number and denitrifiers (nirK, nirS and nosZ gene number, and key soil environmental conditions. Plant diversity effects were largely due to differences in functional group composition between communities of identical richness (number of sown species, though richness also had an effect per se. NEA was positively related to the percentage of legumes in terms of sown species number, the additional effect of richness at any given legume percentage being negative. DEA was higher in plots with legumes, decreased with increasing percentage of grasses, and increased with richness. No correlation was observed between DEA and denitrifier abundance. NEA increased with the abundance of ammonia oxidizing bacteria. The effect of richness on NEA was entirely due to the build-up of nitrifying organisms, while legume effect was partly linked to modified ammonium availability and nitrifier abundance. Richness effect on DEA was entirely due to changes in soil moisture, while the effects of legumes and grasses were partly due to modified nitrate availability, which influenced the specific activity of denitrifiers. These results suggest that plant diversity-induced changes in microbial specific activity are important for facultative activities such as denitrification

  2. Effects of plant diversity, N fertilization, and elevated carbon dioxide on grassland soil N cycling in a long-term experiment.

    Science.gov (United States)

    Mueller, Kevin E; Hobbie, Sarah E; Tilman, David; Reich, Peter B

    2013-04-01

    The effects of global environmental changes on soil nitrogen (N) pools and fluxes have consequences for ecosystem functions such as plant productivity and N retention. In a 13-year grassland experiment, we evaluated how elevated atmospheric carbon dioxide (CO2 ), N fertilization, and plant species richness alter soil N cycling. We focused on soil inorganic N pools, including ammonium and nitrate, and two N fluxes, net N mineralization and net nitrification. In contrast with existing hypotheses, such as progressive N limitation, and with observations from other, often shorter, studies, elevated CO2 had relatively static and small, or insignificant, effects on soil inorganic N pools and fluxes. Nitrogen fertilization had inconsistent effects on soil N transformations, but increased soil nitrate and ammonium concentrations. Plant species richness had increasingly positive effects on soil N transformations over time, likely because in diverse subplots the concentrations of N in roots increased over time. Species richness also had increasingly positive effects on concentrations of ammonium in soil, perhaps because more carbon accumulated in soils of diverse subplots, providing exchange sites for ammonium. By contrast, subplots planted with 16 species had lower soil nitrate concentrations than less diverse subplots, especially when fertilized, probably due to greater N uptake capacity of subplots with 16 species. Monocultures of different plant functional types had distinct effects on N transformations and nitrate concentrations, such that not all monocultures differed from diverse subplots in the same manner. The first few years of data would not have adequately forecast the effects of N fertilization and diversity on soil N cycling in later years; therefore, the dearth of long-term manipulations of plant species richness and N inputs is a hindrance to forecasting the state of the soil N cycle and ecosystem functions in extant plant communities. © 2012 Blackwell

  3. Grassland biodiversity can pay.

    Science.gov (United States)

    Binder, Seth; Isbell, Forest; Polasky, Stephen; Catford, Jane A; Tilman, David

    2018-04-10

    The biodiversity-ecosystem functioning (BEF) literature provides strong evidence of the biophysical basis for the potential profitability of greater diversity but does not address questions of optimal management. BEF studies typically focus on the ecosystem outputs produced by randomly assembled communities that only differ in their biodiversity levels, measured by indices such as species richness. Landholders, however, do not randomly select species to plant; they choose particular species that collectively maximize profits. As such, their interest is not in comparing the average performance of randomly assembled communities at each level of biodiversity but rather comparing the best-performing communities at each diversity level. Assessing the best-performing mixture requires detailed accounting of species' identities and relative abundances. It also requires accounting for the financial cost of individual species' seeds, and the economic value of changes in the quality, quantity, and variability of the species' collective output-something that existing multifunctionality indices fail to do. This study presents an assessment approach that integrates the relevant factors into a single, coherent framework. It uses ecological production functions to inform an economic model consistent with the utility-maximizing decisions of a potentially risk-averse private landowner. We demonstrate the salience and applicability of the framework using data from an experimental grassland to estimate production relationships for hay and carbon storage. For that case, our results suggest that even a risk-neutral, profit-maximizing landowner would favor a highly diverse mix of species, with optimal species richness falling between the low levels currently found in commercial grasslands and the high levels found in natural grasslands.

  4. Embedded mobile farm robot for identification of diseased plants

    Science.gov (United States)

    Sadistap, S. S.; Botre, B. A.; Pandit, Harshavardhan; Chandrasekhar; Rao, Adesh

    2013-07-01

    This paper presents the development of a mobile robot used in farms for identification of diseased plants. It puts forth two of the major aspects of robotics namely automated navigation and image processing. The robot navigates on the basis of the GPS (Global Positioning System) location and data obtained from IR (Infrared) sensors to avoid any obstacles in its path. It uses an image processing algorithm to differentiate between diseased and non-diseased plants. A robotic platform consisting of an ARM9 processor, motor drivers, robot mechanical assembly, camera and infrared sensors has been used. Mini2440 microcontroller has been used wherein Embedded linux OS (Operating System) is implemented.

  5. Algorithm of Dynamic Model Structural Identification of the Multivariable Plant

    Directory of Open Access Journals (Sweden)

    Л.М. Блохін

    2004-02-01

    Full Text Available  The new algorithm of dynamic model structural identification of the multivariable stabilized plant with observable and unobservable disturbances in the regular operating  modes is offered in this paper. With the help of the offered algorithm it is possible to define the “perturbed” models of dynamics not only of the plant, but also the dynamics characteristics of observable and unobservable casual disturbances taking into account the absence of correlation between themselves and control inputs with the unobservable perturbations.

  6. Identification of a nuclear plant dynamics via ARMAX model

    International Nuclear Information System (INIS)

    Yamamoto, Shigeki; Otsuji, Tomoo; Muramatsu, Eiichi

    2000-01-01

    Dynamics of the reactor of nuclear ship 'Mutsu' is described by a linear time-invariant discrete-time model which is referred to as ARMAX (Auto-Regressive Moving Average eXogenious inputs) model. Applying system identification methods, parameters of the ARMAX model are determined from input-output data of the reactor. Accuracy of the model is examined in time and frequency domain. We show that the model can be a good approximation of the plant dynamics. (author)

  7. B plant standards/requirements identification document (S/RID)

    Energy Technology Data Exchange (ETDEWEB)

    Maddox, B.S., Westinghouse Hanford

    1996-07-29

    This Standards/Requirements Identification Document (S/RID) set forth the Environmental Safety and Health (ES{ampersand}H) standards/requirements for the B Plant. This S/RID is applicable to the appropriate life cycle phases of design, construction,operation, and preparation for decommissioning. These standards/requirements are adequate to ensure the protection of the health and safety of workers, the public, and the environment.

  8. Soil disturbance as a grassland restoration measure

    DEFF Research Database (Denmark)

    Schnoor, Tim; Bruun, Hans Henrik; Olsson, Pål Axel

    2015-01-01

    Soil disturbance is recognized as an important driver of biodiversity in dry grasslands, and can therefore be implemented as a restoration measure. However, because community re-assembly following disturbance includes stochastic processes, a focus only on species richness or establishment success...... to experimental disturbance treatments (ploughing or rotavation), and the vegetation was surveyed during four subsequent years of succession. Treated plots were compared with control plots representing untreated grassland, as well as nearby plots characterized by plant communities representing the restoration...

  9. Computational identification of candidate nucleotide cyclases in higher plants

    KAUST Repository

    Wong, Aloysius Tze

    2013-09-03

    In higher plants guanylyl cyclases (GCs) and adenylyl cyclases (ACs) cannot be identified using BLAST homology searches based on annotated cyclic nucleotide cyclases (CNCs) of prokaryotes, lower eukaryotes, or animals. The reason is that CNCs are often part of complex multifunctional proteins with different domain organizations and biological functions that are not conserved in higher plants. For this reason, we have developed CNC search strategies based on functionally conserved amino acids in the catalytic center of annotated and/or experimentally confirmed CNCs. Here we detail this method which has led to the identification of >25 novel candidate CNCs in Arabidopsis thaliana, several of which have been experimentally confirmed in vitro and in vivo. We foresee that the application of this method can be used to identify many more members of the growing family of CNCs in higher plants. © Springer Science+Business Media New York 2013.

  10. Species turnover drives β-diversity patterns across multiple spatial scales of plant-galling interactions in mountaintop grasslands.

    Science.gov (United States)

    Coelho, Marcel Serra; Carneiro, Marco Antônio Alves; Branco, Cristina Alves; Borges, Rafael Augusto Xavier; Fernandes, Geraldo Wilson

    2018-01-01

    This study describes differences in species richness and composition of the assemblages of galling insects and their host plants at different spatial scales. Sampling was conducted along altitudinal gradients composed of campos rupestres and campos de altitude of two mountain complexes in southeastern Brazil: Espinhaço Range and Mantiqueira Range. The following hypotheses were tested: i) local and regional richness of host plants and galling insects are positively correlated; ii) beta diversity is the most important component of regional diversity of host plants and galling insects; and iii) Turnover is the main mechanism driving beta diversity of both host plants and galling insects. Local richness of galling insects and host plants increased with increasing regional richness of species, suggesting a pattern of unsaturated communities. The additive partition of regional richness (γ) into local and beta components shows that local richnesses (α) of species of galling insects and host plants are low relative to regional richness; the beta (β) component incorporates most of the regional richness. The multi-scale analysis of additive partitioning showed similar patterns for galling insects and host plants with the local component (α) incorporated a small part of regional richness. Beta diversity of galling insects and host plants were mainly the result of turnover, with little contribution from nesting. Although the species composition of galling insects and host plant species varied among sample sites, mountains and even mountain ranges, local richness remained relatively low. In this way, the addition of local habitats with different landscapes substantially affects regional richness. Each mountain contributes fundamentally to the composition of regional diversity of galling insects and host plants, and so the design of future conservation strategies should incorporate multiple scales.

  11. Technology-Enhanced Formative Assessment of Plant Identification

    Science.gov (United States)

    Conejo, Ricardo; Garcia-Viñas, Juan Ignacio; Gastón, Aitor; Barros, Beatriz

    2016-04-01

    Developing plant identification skills is an important part of the curriculum of any botany course in higher education. Frequent practice with dried and fresh plants is necessary to recognize the diversity of forms, states, and details that a species can present. We have developed a web-based assessment system for mobile devices that is able to pose appropriate questions according to the location of the student. A student's location can be obtained using the device position or by scanning a QR code attached to a dried plant sheet in a herbarium or to a fresh plant in an arboretum. The assessment questions are complemented with elaborated feedback that, according to the students' responses, provides indications of possible mistakes and correct answers. Three experiments were designed to measure the effectiveness of the formative assessment using dried and fresh plants. Three questionnaires were used to evaluate the system performance from the students' perspective. The results clearly indicate that formative assessment is objectively effective compared to traditional methods and that the students' attitudes towards the system were very positive.

  12. Greater soil carbon accumulation in deeper soils in native- than in exotic-dominated grassland plantings in the southern Plains

    Science.gov (United States)

    Wilsey, B. J.; Xu, X.; Polley, H. W.; Hofmockel, K. S.

    2017-12-01

    Global change includes invasion by non-native plant species, and invasion may affect carbon cycling and storage. We tested predictions in central Texas in an experiment that compares mixtures of all exotic or all native species under two summer irrigation treatments (128 or 0 mm) that varies the amount of summer drought stress. At the end of the eighth growing season after establishment, soils were sampled in 10 cm increments to 100 cm depth to determine if soil C differed among treatments, and if treatments differentially affected soil C in deeper soils. Soil C content was significantly (5%) higher under native plantings than under exotic species plantings (P plantings increased with depth, and native plantings had higher soil C in deeper soil layers than in surface layers (native-exotic x depth, P plantings had decreasing soil C with depth. Soil C:N ratio and δ13C/12C were also significantly affected by native-exotic status, with soils in exotic plots having a significantly greater C4 contribution than native soils. Soil C was unaffected by summer irrigation treatments. Our results suggest that a significant amount of carbon could be sequestered by replacing exotic plant species with native species in the southern Plains, and that more work should be conducted at deeper soil depths. If we had restricted our analyses to surface soil layers (e.g. top 30 cm), we would have failed to detect depth differences between natives and exotics.

  13. SOWING GRASSLANDS – EFFICIENT SOLUTION FOR ZOOTEHNICAL PRODUCTION

    Directory of Open Access Journals (Sweden)

    VALENTINA OFELIA ROBESCU

    2008-05-01

    Full Text Available Recruitment is critical for the maintenance of plant populations and community diversity, but sexual regeneration is considered to be infrequent in climatically harsh habitats such as sub alpine grasslands. For this reasons it is very important to improve the grassland. In this paper we study the interaction among milk production, fertilizations and flower composition in sub alpine grasslands. The agrochemical indicators are important because they influence the pasture value and at the final the milk production.

  14. Satellite-based assessment of grassland yields

    Science.gov (United States)

    Grant, K.; Siegmund, R.; Wagner, M.; Hartmann, S.

    2015-04-01

    Cutting date and frequency are important parameters determining grassland yields in addition to the effects of weather, soil conditions, plant composition and fertilisation. Because accurate and area-wide data of grassland yields are currently not available, cutting frequency can be used to estimate yields. In this project, a method to detect cutting dates via surface changes in radar images is developed. The combination of this method with a grassland yield model will result in more reliable and regional-wide numbers of grassland yields. For the test-phase of the monitoring project, a study area situated southeast of Munich, Germany, was chosen due to its high density of managed grassland. For determining grassland cutting robust amplitude change detection techniques are used evaluating radar amplitude or backscatter statistics before and after the cutting event. CosmoSkyMed and Sentinel-1A data were analysed. All detected cuts were verified according to in-situ measurements recorded in a GIS database. Although the SAR systems had various acquisition geometries, the amount of detected grassland cut was quite similar. Of 154 tested grassland plots, covering in total 436 ha, 116 and 111 cuts were detected using CosmoSkyMed and Sentinel-1A radar data, respectively. Further improvement of radar data processes as well as additional analyses with higher sample number and wider land surface coverage will follow for optimisation of the method and for validation and generalisation of the results of this feasibility study. The automation of this method will than allow for an area-wide and cost efficient cutting date detection service improving grassland yield models.

  15. (134)Cs and ¹³⁷Cs levels in a grassland, 32 km northwest of the Fukushima 1 Nuclear Power Plant, measured for two seasons after the fallout.

    Science.gov (United States)

    Terashima, Ichiro; Shiyomi, Masae; Fukuda, Hiroo

    2014-01-01

    We measured the levels of radioactive caesium (RACs; ¹³⁴Cs and ¹³⁷Cs) in plants and soil in a grassland, 32 km northwest of the Fukushima 1 Nuclear Power Plant, from June 2011 to October 2012. In 2011, the highest RACs levels (¹³⁴Cs + ¹³⁷Cs) in plants and in the 0-5 cm soil layer were approximately 80 kBq per kg dry weight (DW). Forage grasses and clovers in this grassland showed similar RACs levels. On a DW basis, the levels of RACs in these plants tended to increase with increasing biomass over both years, but the absolute levels decreased in 2012. The RACs levels in the soil decreased sharply with soil depth; the RACs level in the 5-10 cm soil layer was only 3 % of that in the 0-5 cm layer. The transfer factor (ratio of radioactivity in plant parts on DW basis to that in the 0-10 cm soil layer) was 0.5 and 1.0 for the aboveground and belowground plant parts, respectively, in 2011, and these values decreased by approximately 50 % in 2012. We discuss the possible mechanisms underlying these trends, and strategies to decrease the level of RACs in plants to the permissible level for forage.

  16. The Use of Fta Card on Dna Sample Preparation for Molecular of Plant Disease Identification

    OpenAIRE

    Sulistyawati, Purnamila; Rimbawanto, Anto

    2007-01-01

    Accurate and guick identification of pathogen is key to control the spread of plant disesases. Morphological identification is often ineffective because it requires fruit body which often are not presence, rely on characters which may be highly variable within and among species and can be slow and time consuming. Molecular identification of plant disease can overcome most of the shortcomings of morphological identification. Application of FTA Cardn for sample collection is crucial for the su...

  17. Effect of four plant species on soil 15N-access and herbage yield in temporary agricultural grasslands

    DEFF Research Database (Denmark)

    Pirhofter-Walzl, Karin; Eriksen, Jørgen; Rasmussen, Jim

    2013-01-01

    access to greater amounts of soil 15N compared with a shallow-rooting binary mixture, and if leguminous plants affect herbage yield and soil 15N-access. Methods 15N-enriched ammonium-sulphate was placed at three different soil depths (0.4, 0.8 and 1.2 m) to determine the depth dependent soil 15N....... This positive plant diversity effect could not be explained by complementary soil 15N-access of the different plant species from 0.4, 0.8 and 1.2 m soil depths, even though deep-rooting chicory acquired relatively large amounts of deep soil 15N and shallow-rooting perennial ryegrass when grown in a mixture...

  18. Relative Importance of Current and Past Landscape Structure and Local Habitat Conditions for Plant Species Richness in Dry Grassland-Like Forest Openings

    Czech Academy of Sciences Publication Activity Database

    Husáková, I.; Münzbergová, Zuzana

    2014-01-01

    Roč. 9, č. 5 (2014), s. 1-15 E-ISSN 1932-6203 Institutional support: RVO:67985939 Keywords : landscape structure * species richness * dry grassland Subject RIV: EF - Botanics Impact factor: 3.234, year: 2014

  19. Competitive interactions between a nonmycorrhizal invasive plant, Alliaria petiolata, and a suite of mycorrhizal grassland, old field, and forest species.

    Science.gov (United States)

    Poon, Gary T; Maherali, Hafiz

    2015-01-01

    The widespread invasion of the nonmycorrhizal biennial plant, Alliaria petiolata in North America is hypothesized to be facilitated by the production of novel biochemical weapons that suppress the growth of mycorrhizal fungi. As a result, A. petiolata is expected to be a strong competitor against plant species that rely on mycorrhizal fungi for nutrient uptake services. If A. petiolata is also a strong competitor for soil resources, it should deplete nutrients to levels lower than can be tolerated by weaker competitors. Because the negative effect of losing the fungal symbiont for mycorrhizal plants is greatest when nutrients are low, the ability of A. petiolata to simultaneously suppress fungi and efficiently take up soil nutrients should further strengthen its competitive ability against mycorrhizal plants. To test this hypothesis, we grew 27 mycorrhizal tree, forb and grass species that are representative of invaded habitats in the absence or presence of competition with A. petiolata in soils that had previously been experimentally planted with the invader or left as a control. A history of A. petiolata in soil reduced plant available forms of nitrogen by >50% and phosphorus by 17% relative to control soil. Average mycorrhizal colonization of competitor species was reduced by >50% in A. petiolata history versus control soil. Contrary to expectations, competition between A. petiolata and other species was stronger in control than history soil. The invader suppressed the biomass of 70% of competitor species in control soil but only 26% of species in history soil. In addition, A. petiolata biomass was reduced by 56% in history versus control soil, whereas the average biomass of competitor species was reduced by 15%. Thus, our results suggest that the negative effect of nutrient depletion on A. petiolata was stronger than the negative effect of suppressing mycorrhizal colonization on competitor species. These findings indicate that the inhibitory potential of A

  20. Relative importance of current and past landscape structure and local habitat conditions for plant species richness in dry grassland-like forest openings.

    Science.gov (United States)

    Husáková, Iveta; Münzbergová, Zuzana

    2014-01-01

    In fragmented landscapes, plant species richness may depend not only on local habitat conditions but also on landscape structure. In addition, both present and past landscape structure may be important for species richness. There are, however, only a few studies that have investigated the relative importance of all of these factors. The aim of this study was to examine the effect of current and past landscape structures and habitat conditions on species richness at dry grassland-like forest openings in a forested landscape and to assess their relative importance for species richness. We analyzed information on past and present landscape structures using aerial photographs from 1938, 1973, 1988, 2000 and 2007. We calculated the area of each locality and its isolation in the present and in the past and the continuity of localities in GIS. At each locality, we recorded all vascular plant species (296 species in 110 forest openings) and information on abiotic conditions of the localities. We found that the current species richness of the forest openings was significantly determined by local habitat conditions as well as by landscape structure in the present and in the past. The highest species richness was observed on larger and more heterogeneous localities with rocks and shallow soils, which were already large and well connected to other localities in 1938. The changes in the landscape structure in the past can thus have strong effects on current species richness. Future studies attempting to understand determinants of species diversity in fragmented landscapes should also include data on past landscape structure, as it may in fact be more important than the present structure.

  1. Effects Of Elevated Ozone On Leaf {delta} {sup 13} C And Leaf Conductance Of Plant Species Grown In Semi-Natural Grassland With Or Without Irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Jaeggi, M.; Saurer, M.; Volk, M. [Agroscope-FAL (Switzerland); Fuhrer, J. [Agroscope-FAL (Switzerland)

    2005-03-01

    At the Swiss prealpine site Le Mouret (754 m a.s.l. 46deg 45min N / 7deg 10min E), semi-natural grassland species were kept under ambient or elevated ozone, paired with or without additional irrigation. Two of the four investigated grassland species showed an additive increase in {sup 13}C-values under drought and elevated ozone conditions. (author)

  2. Life-history constraints in grassland plant species: a growth-defence trade-off is the norm

    Science.gov (United States)

    E.M. Lind; E.T. Borer; E.W. Seabloom; P.B. Adler; J.D. Bakker; D.M. Blumenthal; M. Crawley; K.F. Davies; J. Firn; D.S. Gruner; S. Harpole; Y. Hautier; H. Hillebrand; J.M.H. Knops; B.A. Melbourne; B. Mortensen; A.C. Risch; M. Schuetz; C.J. Stevens; P.D. Wragg

    2013-01-01

    Plant growth can be limited by resource acquisition and defence against consumers, leading to contrasting trade-off possibilities. The competition-defence hypothesis posits a trade-off between competitive ability and defence against enemies (e.g. herbivores and pathogens). The growth-defence hypothesis suggests that strong competitors for nutrients are also defended...

  3. Positive plant diversity-soil stability relationships are mediated through roots in the Songnen Grassland: Chronosequence evidence

    Science.gov (United States)

    Liang-Jun Hu; Ping Li; Qinfeng Guo

    2013-01-01

    Living plant diversity (excluding the litter issue) may affect below-ground properties and processes, which is critical to obtaining an integrated biodiversity-ecosystem functioning theory. However, related patterns and underlying mechanisms have rarely been examined, especially lacking long-term evidence. We conducted a factorial crossed sample survey to examine the...

  4. Water- and plant-mediated responses of ecosystem carbon fluxes to warming and nitrogen addition on the Songnen grassland in northeast China.

    Directory of Open Access Journals (Sweden)

    Li Jiang

    Full Text Available Understanding how grasslands are affected by a long-term increase in temperature is crucial to predict the future impact of global climate change on terrestrial ecosystems. Additionally, it is not clear how the effects of global warming on grassland productivity are going to be altered by increased N deposition and N addition.In-situ canopy CO(2 exchange rates were measured in a meadow steppe subjected to 4-year warming and nitrogen addition treatments. Warming treatment reduced net ecosystem CO(2 exchange (NEE and increased ecosystem respiration (ER; but had no significant impacts on gross ecosystem productivity (GEP. N addition increased NEE, ER and GEP. However, there were no significant interactions between N addition and warming. The variation of NEE during the four experimental years was correlated with soil water content, particularly during early spring, suggesting that water availability is a primary driver of carbon fluxes in the studied semi-arid grassland.Ecosystem carbon fluxes in grassland ecosystems are sensitive to warming and N addition. In the studied water-limited grassland, both warming and N addition influence ecosystem carbon fluxes by affecting water availability, which is the primary driver in many arid and semiarid ecosystems. It remains unknown to what extent the long-term N addition would affect the turn-over of soil organic matter and the C sink size of this grassland.

  5. System identification of the Arabidopsis plant circadian system

    Science.gov (United States)

    Foo, Mathias; Somers, David E.; Kim, Pan-Jun

    2015-02-01

    The circadian system generates an endogenous oscillatory rhythm that governs the daily activities of organisms in nature. It offers adaptive advantages to organisms through a coordination of their biological functions with the optimal time of day. In this paper, a model of the circadian system in the plant Arabidopsis (species thaliana) is built by using system identification techniques. Prior knowledge about the physical interactions of the genes and the proteins in the plant circadian system is incorporated in the model building exercise. The model is built by using primarily experimentally-verified direct interactions between the genes and the proteins with the available data on mRNA and protein abundances from the circadian system. Our analysis reveals a great performance of the model in predicting the dynamics of the plant circadian system through the effect of diverse internal and external perturbations (gene knockouts and day-length changes). Furthermore, we found that the circadian oscillatory rhythm is robust and does not vary much with the biochemical parameters except those of a light-sensitive protein P and a transcription factor TOC1. In other words, the circadian rhythmic profile is largely a consequence of the network's architecture rather than its particular parameters. Our work suggests that the current experimental knowledge of the gene-to-protein interactions in the plant Arabidopsis, without considering any additional hypothetical interactions, seems to suffice for system-level modeling of the circadian system of this plant and to present an exemplary platform for the control of network dynamics in complex living organisms.

  6. Changes in plant functional groups, litter quality, and soil carbon and nitrogen mineralization with sheep grazing in an Inner Mongolian Grassland

    Science.gov (United States)

    Barger, N.N.; Ojima, D.S.; Belnap, J.; Shiping, W.; Yanfen, W.; Chen, Z.

    2004-01-01

    This study reports on changes in plant functional group composition, litter quality, and soil C and N mineralization dynamics from a 9-year sheep grazing study in Inner Mongolia. Addressed are these questions: 1) How does increasing grazing intensity affect plant community composition? 2) How does increasing grazing intensity alter soil C and N mineralization dynamics? 3) Do changes in soil C and N mineralization dynamics relate to changes in plant community composition via inputs of the quality or quantity of litter? Grazing plots were set up near the Inner Mongolia Grassland Ecosystem Research Station (IMGERS) with 5 grazing intensities: 1.3, 2.7, 4.0, 5.3, and 6.7 sheep ha -1??yr-1. Plant cover was lower with increasing grazing intensity, which was primarily due to a dramatic decline in grasses, Carex duriuscula, and Artemisia frigida. Changes in litter mass and percentage organic C resulted in lower total C in the litter layer at 4.0 and 5.3 sheep ha-1??yr-1 compared with 2.7 sheep ha -1??yr-1. Total litter N was lower at 5.3 sheep ha-1??yr-1 compared with 2.7 sheep ha -1??yr-1. Litter C:N ratios, an index of litter quality, were significantly lower at 4.0 sheep ha-1??yr -1 relative to 1.3 and 5.3 sheep ha-1??yr -1. Cumulative C mineralized after 16 days decreased with increasing grazing intensity. In contrast, net N mineralization (NH4+ + NO3-) after a 12-day incubation increased with increasing grazing intensity. Changes in C and N mineralization resulted in a narrowing of CO2-C:net Nminratios with increasing grazing intensity. Grazing explained 31% of the variability in the ratio of CO 2-C:net Nmin. The ratio of CO2-C:net N min was positively correlated with litter mass. Furthermore, there was a positive correlation between litter mass and A. frigida cover. Results suggest that as grazing intensity increases, microbes become more C limited resulting in decreased microbial growth and demand for N.

  7. Plant species and functional group effects on abiotic and microbial soil properties and plant-soil feedback responses in two grasslands

    NARCIS (Netherlands)

    Bezemer, T.M.; Lawson, C.S.; Hedlund, K.; Edwards, A.R.; Brooks, A.J.; Igual, J.M.; Mortimer, S.R.; Putten, van der W.H.

    2006-01-01

    1 Plant species differ in their capacity to influence soil organic matter, soil nutrient availability and the composition of soil microbial communities. Their influences on soil properties result in net positive or negative feedback effects, which influence plant performance and plant community

  8. Primer and barcode gap identification and DNA barcode generation for species discrimination in plants

    OpenAIRE

    Deepu Mathew

    2015-01-01

    This book chapter details the protocols for DNA barcoding in plants, starting from DNA isolation, sequencing, sequence annotation using MEGA, till identification of barcode gaps. A good chapter for beginners in plant taxonomy

  9. The KKS power plant identification system. 3. ed.

    International Nuclear Information System (INIS)

    1988-01-01

    The previous first and second editions of the KKS, system for power plant identification, consisted of the following: introduction; instructions for application with a comparative presentation of the DIN/KKS systems and subject index; keys (functional key, equipment key, operating media key). The third edition now available incorporates the following revisions and additions: instructions for application refer exclusively to the KKS system; key updates; revised coordinating file for the equipment key and operating media key; a completely new section entitled 'Agreements for coordination of project activities', in an annex to the KKS instructions; comparison DIN/KKS adapted to new version of KKS instructions; the subject index of the 2nd edition has been extended by a keyword index referring to the explanations for application of the KKS system. (orig./HP) [de

  10. The California Valley grassland

    Science.gov (United States)

    Keeley, J.E.; Schoenherr, Allan A.

    1990-01-01

    Grasslands are distributed throughout California from Oregon to Baja California Norte and from the coast to the desert (Brown 1982) (Figure 1). This review will focus on the dominant formation in cismontane California, a community referred to as Valley Grassland (Munz 1959). Today, Valley Grassland is dominated by non-native annual grasses in genera such as Avena (wild oat), Bromus (brome grass), and Hordeum (barley), and is often referred to as the California annual grassland. On localized sites, native perennial bunchgrasses such as Stipa pultra (purple needle grass) may dominate and such sites are interpreted to be remnants of the pristine valley grassland. In northwestern California a floristically distinct formation of the Valley Grassland, known as Coast Prairie (Munz 1959) or Northern Coastal Grassland (Holland and Keil 1989) is recognized. The dominant grasses include many native perennial bunchgrasses in genera such as Agrostis, Calamagrostis, Danthonia, Deschampsia, Festuca, Koeleria and Poa (Heady et al. 1977). Non-native annuals do not dominate, but on some sites non-native perennials like Anthoxanthum odoratum may colonize the native grassland (Foin and Hektner 1986). Elevationally, California's grasslands extend from sea level to at leas 1500 m. The upper boundary is vague because montane grassland formations are commonly referred to as meadows; a community which Munz (1959) does not recognize. Holland and Keil (1989) describe the montane meadow as an azonal community; that is, a community restricted not so much to a particular climatic zone but rather controlled by substrate characteristics. They consider poor soil-drainage an over-riding factor in the development of montane meadows and, in contrast to grasslands, meadows often remain green through the summer drought. Floristically, meadows are composed of graminoids; Cyperaceae, Juncaceae, and rhizomatous grasses such as Agropyron (wheat grass). Some bunchgrasses, such as Muhlenbergia rigens, are

  11. Genome-Enhanced Detection and Identification (GEDI of plant pathogens

    Directory of Open Access Journals (Sweden)

    Nicolas Feau

    2018-02-01

    Full Text Available Plant diseases caused by fungi and Oomycetes represent worldwide threats to crops and forest ecosystems. Effective prevention and appropriate management of emerging diseases rely on rapid detection and identification of the causal pathogens. The increase in genomic resources makes it possible to generate novel genome-enhanced DNA detection assays that can exploit whole genomes to discover candidate genes for pathogen detection. A pipeline was developed to identify genome regions that discriminate taxa or groups of taxa and can be converted into PCR assays. The modular pipeline is comprised of four components: (1 selection and genome sequencing of phylogenetically related taxa, (2 identification of clusters of orthologous genes, (3 elimination of false positives by filtering, and (4 assay design. This pipeline was applied to some of the most important plant pathogens across three broad taxonomic groups: Phytophthoras (Stramenopiles, Oomycota, Dothideomycetes (Fungi, Ascomycota and Pucciniales (Fungi, Basidiomycota. Comparison of 73 fungal and Oomycete genomes led the discovery of 5,939 gene clusters that were unique to the targeted taxa and an additional 535 that were common at higher taxonomic levels. Approximately 28% of the 299 tested were converted into qPCR assays that met our set of specificity criteria. This work demonstrates that a genome-wide approach can efficiently identify multiple taxon-specific genome regions that can be converted into highly specific PCR assays. The possibility to easily obtain multiple alternative regions to design highly specific qPCR assays should be of great help in tackling challenging cases for which higher taxon-resolution is needed.

  12. Decomposition of standing litter in arid grasslands: Interactions between sunlight, non-rainfall moisture, microbes, and plant traits

    Science.gov (United States)

    Logan, J. R. V.; Jacobson, P. J.; Jacobson, K. M.; Evans, S.

    2017-12-01

    Although arid lands make up 40% of the Earth's land surface, we still lack a strong understanding of carbon cycling and plant decomposition in these systems. One reason for this is that field studies typically only focus on decomposition at or below the ground surface even though standing dead litter (material that has not yet fallen to the ground) accounts for more than 50% of total necromass in many of these systems. While recent work has begun to recognize the important and unique aspects of standing litter decomposition, few studies have investigated specific mechanisms controlling rates of mass loss. We hypothesized that initial photodegradation of the outer plant cuticle of standing litter is an important determinant of litter decomposition because this process increases moisture absorption and subsequent opportunities for biological decomposition. Our preliminary results offer support for this hypothesis. We found that standing grass stems with their cuticles artificially removed had greater water absorbance and more than 400% greater mass loss over a 6-month period relative to controls with intact cuticles. Additionally, spectroscopic measurements of cuticle integrity showed damage to the litter surface after a period of extended photodegradation, allowing increased moisture uptake during simulated fog/dew events. These findings are especially important in the context of recent work by us and others showing that non-rainfall moisture (fog, dew, and water vapor) plays a much larger role in arid land decomposition than previously thought. Improving our understanding of the mechanisms driving decomposition of standing litter will enable us to develop a more predictive understanding of carbon storage in arid lands.

  13. Soil acidification and liming in grassland production and grassland soil fertility in Slovenia

    Directory of Open Access Journals (Sweden)

    Jure ČOP

    2015-12-01

    Full Text Available This paper reviews the evidences on grassland soil acidity and liming in relation to soil processes and herbage production. There is also an outline of the present state of soil acidity and acidity-related traits – contents of organic matter (OM, phosphorus (P and potassium (K in Slovene grassland. In grassland, soil acidification is an ongoing process under humid climate conditions. It is mainly driven by leaching of nutrients, net loss of cations due to retention in livestock products, use of physiologically acid fertilizers, acid rain and N2 fixation. This process is reduced by strong pH buffering capacity of the soil and by physiologically basic fertilizers. Acid grassland soils in Slovenia are widely distributed in spite of the fact that 44% of the total land has developed from a carbonate parent material. Of the 1713 grassland soil samples analysed during 2005-2007 45% were regarded as acid ones (pH < 5.5; in KCl, 57% as soils with very low P status (˂ 6 mg P2O5/100 g soil and 22% as soils with very low K status (˂ 10 mg K2O/100 soil. Increased content of soil organic matter was identified for alpine pastures (˃ 10 % OM in 44% of samples, mainly as a result of low decomposition rate. Liming of acid grassland soils did not always reflect in a higher herbage yield. The cause for this inefficiency is plant composition of grassland. Thus, many grassland plants with relatively high production potential have adapted to acid soil conditions. To illustrate the inconsistent liming effect three researches are reviewed. In the first two researches liming along with fertilizer application did not increase the yield comparing to the fertilized control while in the third research the increase amounted 26 %. Liming improves considerably botanical composition of the acid grassland (e.g. sward where Common Bent – Agrostis tenuis Sibth. – prevails and thus indirectly affects palatability and nutritive value of herbage. Grassland liming has a weak

  14. Rapid Identification and Verification of Indirubin-Containing Medicinal Plants.

    Science.gov (United States)

    Hu, Zhigang; Tu, Yuan; Xia, Ye; Cheng, Peipei; Sun, Wei; Shi, Yuhua; Guo, Licheng; He, Haibo; Xiong, Chao; Chen, Shilin; Zhang, Xiuqiao

    2015-01-01

    Indirubin, one of the key components of medicinal plants including Isatis tinctoria, Polygonum tinctorium, and Strobilanthes cusia, possesses great medicinal efficacy in the treatment of chronic myelocytic leukemia (CML). Due to misidentification and similar name, materials containing indirubin and their close relatives frequently fall prey to adulteration. In this study, we selected an internal transcribed spacer 2 (ITS2) for distinguishing these indirubin-containing species from five of their usual adulterants, after assessing identification efficiency of matK, rbcL, psbA-trnH, and ITS2 among these species. The results of genetic distances and neighbor-joining (NJ) phylogenetic tree indicated that ITS2 region is a powerful DNA barcode to accurately identify these indirubin-containing species and discriminate them from their adulterants. Additionally, high performance liquid chromatography (HPLC) was used to verify indirubin in different organs of the above species. The results showed that indirubin had been detected in the leaves of Is. tinctoria, P. tinctorium, S. cusia, and Indigo Naturalis (made from their mixture), but not in their roots, or in the leaves of their adulterants. Therefore, this study provides a novel and rapid method to identify and verify indirubin-containing medicinal plants for effective natural treatment of CML.

  15. Rapid Identification and Verification of Indirubin-Containing Medicinal Plants

    Directory of Open Access Journals (Sweden)

    Zhigang Hu

    2015-01-01

    Full Text Available Indirubin, one of the key components of medicinal plants including Isatis tinctoria, Polygonum tinctorium, and Strobilanthes cusia, possesses great medicinal efficacy in the treatment of chronic myelocytic leukemia (CML. Due to misidentification and similar name, materials containing indirubin and their close relatives frequently fall prey to adulteration. In this study, we selected an internal transcribed spacer 2 (ITS2 for distinguishing these indirubin-containing species from five of their usual adulterants, after assessing identification efficiency of matK, rbcL, psbA-trnH, and ITS2 among these species. The results of genetic distances and neighbor-joining (NJ phylogenetic tree indicated that ITS2 region is a powerful DNA barcode to accurately identify these indirubin-containing species and discriminate them from their adulterants. Additionally, high performance liquid chromatography (HPLC was used to verify indirubin in different organs of the above species. The results showed that indirubin had been detected in the leaves of Is. tinctoria, P. tinctorium, S. cusia, and Indigo Naturalis (made from their mixture, but not in their roots, or in the leaves of their adulterants. Therefore, this study provides a novel and rapid method to identify and verify indirubin-containing medicinal plants for effective natural treatment of CML.

  16. [Research progress and trend on grassland agroecology].

    Science.gov (United States)

    Ren, Jizhou; Li, Xianglin; Hou, Fujiang

    2002-08-01

    The connotation, progress, research frontiers and developmental trend of grassland agroecology are discussed in this paper. The interface theory, structure and function, coupling and discordance, and health assessment of grassland agroecosystems were recognized as the four research frontiers of the discipline. There exist three primary interfaces in a grassland agroecosystem, i.e., vegetation-site, grassland-animal and production-management. Research into a series of the ecological processes that occurred at these interfaces is the key to revealing the features of the system behavior. There are four sections in a grassland agroecosystem, i.e., pre-plant, plant, animal and post-biotic sections. System coupling and discordance are the two important concepts to describe interactions among the production sections. System coupling among the sections can lead to system improvement by exerting the potential of system capacity. Health of an ecosystem is a reflection of its structure and function, and health assessment is a measurement of its orderliness and service value.

  17. Dry flue gas desulfurization by-product application effects on plant uptake and soil storage changes in a managed grassland.

    Science.gov (United States)

    Burgess-Conforti, Jason R; Brye, Kristofor R; Miller, David M; Pollock, Erik D; Wood, Lisa S

    2018-02-01

    Environmental regulations mandate that sulfur dioxide (SO 2 ) be removed from the flue gases of coal-fired power plants, which results in the generation of flue gas desulfurization (FGD) by-products. These FGD by-products may be a viable soil amendment, but the large amounts of trace elements contained in FGD by-products are potentially concerning. The objective of this study was to evaluate the effects of land application of a high-Ca dry FGD (DFGD) by-product on trace elements in aboveground biomass and soil. A high-Ca DFGD by-product was applied once at a rate of 9 Mg ha -1 on May 18, 2015 to small plots with mixed-grass vegetation. Soil and biomass were sampled prior to application and several times thereafter. Aboveground dry matter and tissue As, Co, Cr, Hg, Se, U, and V concentrations increased (P  0.05) from pre-application levels or the unamended control within 3 to 6 months of application. Soil pH in the amended treatment 6 months after application was greater (P by-product application compared to the unamended control. High-Ca DFGD by-products appear to be useful as a soil amendment, but cause at least a temporary increase in tissue concentrations of trace elements, which may be problematic for animal grazing situations.

  18. Wetland Plants of Great Salt Lake, A Guide to Identification, Communities, & Bird Habitat

    OpenAIRE

    Downard, Rebekah; Frank, Maureen; Perkins, Jennifer; Kettenring, Karin; Larese-Casanova, Mark

    2017-01-01

    Wetland Plants of Great Salt Lake: a guide to identification, communities, & bird habitat is a wetland plant identification guide, resulting from collaborative research efforts about Great Salt Lake (GSL) wetland conditions and bird habitat. Dr. Rebekah Downard collected dissertation field data from GSL wetlands during 2012–2015, the majority of which informed this work. Dr. Maureen Frank contributed her guide to GSL wetland vegetation and how to manage native plants as high-quality habitat f...

  19. Improved parameterization of managed grassland in a global process-based vegetation model using Bayesian statistics

    Science.gov (United States)

    Rolinski, S.; Müller, C.; Lotze-Campen, H.; Bondeau, A.

    2010-12-01

    More than a quarter of the Earth’s land surface is covered by grassland, which is also the major part (~ 70 %) of the agricultural area. Most of this area is used for livestock production in different degrees of intensity. The dynamic global vegetation model LPJmL (Sitch et al., Global Change Biology, 2003; Bondeau et al., Global Change Biology, 2007) is one of few process-based model that simulates biomass production on managed grasslands at the global scale. The implementation of managed grasslands and its evaluation has received little attention so far, as reference data on grassland productivity are scarce and the definition of grassland extent and usage are highly uncertain. However, grassland productivity is related to large areas, and strongly influences global estimates of carbon and water budgets and should thus be improved. Plants are implemented in LPJmL in an aggregated form as plant functional types assuming that processes concerning carbon and water fluxes are quite similar between species of the same type. Therefore, the parameterization of a functional type is possible with parameters in a physiologically meaningful range of values. The actual choice of the parameter values from the possible and reasonable phase space should satisfy the condition of the best fit of model results and measured data. In order to improve the parameterization of managed grass we follow a combined procedure using model output and measured data of carbon and water fluxes. By comparing carbon and water fluxes simultaneously, we expect well-balanced refinements and avoid over-tuning of the model in only one direction. The comparison of annual biomass from grassland to data from the Food and Agriculture Organization of the United Nations (FAO) per country provide an overview about the order of magnitude and the identification of deviations. The comparison of daily net primary productivity, soil respiration and water fluxes at specific sites (FluxNet Data) provides

  20. Identification of nuclear power plant transients using the Particle Swarm Optimization algorithm

    International Nuclear Information System (INIS)

    Canedo Medeiros, Jose Antonio Carlos; Schirru, Roberto

    2008-01-01

    In order to help nuclear power plant operator reduce his cognitive load and increase his available time to maintain the plant operating in a safe condition, transient identification systems have been devised to help operators identify possible plant transients and take fast and right corrective actions in due time. In the design of classification systems for identification of nuclear power plants transients, several artificial intelligence techniques, involving expert systems, neuro-fuzzy and genetic algorithms have been used. In this work we explore the ability of the Particle Swarm Optimization algorithm (PSO) as a tool for optimizing a distance-based discrimination transient classification method, giving also an innovative solution for searching the best set of prototypes for identification of transients. The Particle Swarm Optimization algorithm was successfully applied to the optimization of a nuclear power plant transient identification problem. Comparing the PSO to similar methods found in literature it has shown better results

  1. Identification of nuclear power plant transients using the Particle Swarm Optimization algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Canedo Medeiros, Jose Antonio Carlos [Universidade Federal do Rio de Janeiro, PEN/COPPE, UFRJ, Ilha do Fundao s/n, CEP 21945-970 Rio de Janeiro (Brazil)], E-mail: canedo@lmp.ufrj.br; Schirru, Roberto [Universidade Federal do Rio de Janeiro, PEN/COPPE, UFRJ, Ilha do Fundao s/n, CEP 21945-970 Rio de Janeiro (Brazil)], E-mail: schirru@lmp.ufrj.br

    2008-04-15

    In order to help nuclear power plant operator reduce his cognitive load and increase his available time to maintain the plant operating in a safe condition, transient identification systems have been devised to help operators identify possible plant transients and take fast and right corrective actions in due time. In the design of classification systems for identification of nuclear power plants transients, several artificial intelligence techniques, involving expert systems, neuro-fuzzy and genetic algorithms have been used. In this work we explore the ability of the Particle Swarm Optimization algorithm (PSO) as a tool for optimizing a distance-based discrimination transient classification method, giving also an innovative solution for searching the best set of prototypes for identification of transients. The Particle Swarm Optimization algorithm was successfully applied to the optimization of a nuclear power plant transient identification problem. Comparing the PSO to similar methods found in literature it has shown better results.

  2. Radiocesium fallout in the grasslands on Sakhalin, Kunashir and Shikotan Islands due to Fukushima accident: the radioactive contamination of soil and plants in 2011

    International Nuclear Information System (INIS)

    Ramzaev, V.; Barkovsky, A.; Goncharova, Yu.; Gromov, A.; Kaduka, M.; Romanovich, I.

    2013-01-01

    The accident at the Fukushima Dai-ichi Nuclear Power Plant has resulted in radioactive contamination of environmental media and food in the Far East of Russia, particularly in the Sakhalin Region. To obtain the knowledge about the 134 Cs and 137 Cs spatial distribution in the Sakhalin Region, soil samples were collected at 31 representative grassland sites on Sakhalin, Kunashir and Shikotan islands (43.80°–46.40° N and 142.73°–146.84° E) in the middle of May and around the end of September to early October 2011. In the autumn, vegetation samples (mixed grass/forb crop and bamboo, Sasa sp.) were collected together with soil samples. Maximum measured activity concentrations (on dry weight) of 134 Cs and 137 Cs in soil were 30 Bq kg −1 and 210 Bq kg −1 , respectively. Within soil profile, 134 Cs activity concentrations declined rapidly with depth. Although for both sampling occasions (in the spring and autumn) the radionuclide was completely retained in the upper 3–4 cm of soil, a deeper penetration of the contaminant into the ground was observed in the autumn. In contrast with 134 Cs, activity concentrations of 137 Cs demonstrated a broad range of the vertical distribution in soil; at most sites, the radionuclide was found down to a depth of 20 cm. This resulted from interfering the aged pre-accidental 137 Cs and the new Fukushima-borne 137 Cs. To calculate contribution of these sources to the inventory of 137 Cs, the 134 Cs: 137 Cs activity ratio of 1:1 in Fukushima fallout (the reference date 15 March 2011) was used. The maximum deposition density of Fukushima-derived 137 Cs was found on Shikotan and Kunashir Islands with average density of 0.124 ± 0.018 kBq m −2 and 0.086 ± 0.026 kBq m −2 , respectively. Sakhalin Island was less contaminated by Fukushima-derived 137 Cs of 0.021 ± 0.018 kBq m −2 . For the south of Sakhalin Island, the reference inventory of pre-Fukushima 137 Cs was calculated as 1.93 ± 0.25 kBq m −2 (reference date 15

  3. Modeling impacts of climate change and grazing effects on plant biomass and soil organic carbon in the Qinghai-Tibetan grasslands

    Science.gov (United States)

    Zhang, Wenjuan; Zhang, Feng; Qi, Jiaguo; Hou, Fujiang

    2017-12-01

    The Qinghai Province supports over 40 % of the human population of the Qinghai-Tibetan Plateau (QTP) but occupies about 29 % of its land area, and thus it plays an important role in the plateau. The dominant land cover is grassland, which has been severely degraded over the last decade due to a combination of increased human activities and climate change. Numerous studies indicate that the plateau is sensitive to recent global climate change, but the drivers and consequences of grassland ecosystem change are controversial, especially the effects of climate change and grazing patterns on the grassland biomass and soil organic carbon (SOC) storage in this region. In this study, we used the DeNitrification-DeComposition (DNDC) model and two climate change scenarios (representative concentration pathways: RCP4.5 and RCP8.5) to understand how the grassland biomass and SOC pools might respond to different grazing intensities under future climate change scenarios. More than 1400 grassland biomass sampling points and 46 SOC points were used to validate the simulated results. The simulated above-ground biomass and SOC concentrations were in good agreement with the measured data (R2 0.71 and 0.73 for above-ground biomass and SOC, respectively). The results showed that climate change may be the major factor that leads to fluctuations in the grassland biomass and SOC, and it explained 26.4 and 47.7 % of biomass and SOC variation, respectively. Meanwhile, the grazing intensity explained 6.4 and 2.3 % variation in biomass and SOC, respectively. The project average biomass and SOC between 2015 and 2044 was significantly smaller than past 30 years (1985-2014), and it was 191.17 g C m-2, 63.44 g C kg-1 and 183.62 g C m-2, 63.37 g C kg-1 for biomass and SOC under RCP4.5 and RCP8.5, respectively. The RCP8.5 showed the more negative effect on the biomass and SOC compared with RCP4.5. Grazing intensity had a negative relationship with biomass and positive relationship with SOC

  4. A checklist of the plants of the forests and grasslands in the Weza district, southern KwaZulu-Natal and a review of their status in the Red Data List

    Directory of Open Access Journals (Sweden)

    Graham R.H. Grieve

    2015-09-01

    Full Text Available Eastern mistbelt forests are naturally fragmented forests with grassland which occur from the Eastern Cape to KwaZulu-Natal, South Africa. These were heavily logged by colonial settlers and continue to be harvested despite being protected. Consequently we documented a checklist of the plants of the forests and grasslands in the Weza district (3029DA WEZA, southern KwaZulu-Natal, including Ngeli Forest and nearby indigenous forest patches to highlight their biodiversity status and need for conservation. We also reviewed their status in the Red Data List. Of the 1554 records included in this summary of plant species for the Weza district, there were 6 lichens (0.4%, 46 bryophytes (3.0%, 58 pteridophytes (3.7%, 6 gymnosperms (0.4% and the remaining 1424 species angiosperms (92.5%. Of the angiosperms, 27.3% were monocotyledons and 72.7% were dicotyledons. The most species-rich family was Asteraceae (239 species followed by Fabaceae (115 species, Liliaceae (used for purposes of comparison against older studies – 89 species, Orchidaceae (89 species, Iridaceae (59 species, Poaceae (58 species, Asclepidaceae (again used for purposes of comparison against older studies – 57 species, Scrophulariaceae (42 species, Euphorbiaceae (32 species, Lamiaceae (32 species and Rubiaceae (27 species. These 10 families each comprised more than 2% of the species in the list. Together they contributed 55% of the angiosperm species and 34.1% of the angiosperm genera. The biodiversity and conservation value of the study area are conserved pockets of eastern mistbelt forest, Drakensberg foothill moist grassland and mistbelt grassland. More than 4% of the species are under some degree of threat, as was evidenced by the number of species regarded as endangered (5, vulnerable (18, near threatened (10, critically rare (1, rare (20 or declining (11 amongst the 1554 species covered in the list. Conservation implications: In terms of taxa under some degree of threat, number of

  5. Draft Genome Sequence of Bacillus velezensis 3A-25B, a Strain with Biocontrol Activity against Fungal and Oomycete Root Plant Phytopathogens, Isolated from Grassland Soil.

    Science.gov (United States)

    Martínez-Raudales, Inés; De La Cruz-Rodríguez, Yumiko; Vega-Arreguín, Julio; Alvarado-Gutiérrez, Alejandro; Fraire-Mayorga, Atzin; Alvarado-Rodríguez, Miguel; Balderas-Hernández, Victor; Gómez-Soto, José Manuel; Fraire-Velázquez, Saúl

    2017-09-28

    Here, we present the draft genome of Bacillus velezensis 3A-25B, which totaled 4.01 Mb with 36 contigs, 3,948 genes, and a GC content of 46.34%. This strain, which demonstrates biocontrol activity against root rot causal phytopathogens in horticultural crops and friendly interactions in roots of pepper plantlets, was obtained from grassland soil in Zacatecas Province, Mexico. Copyright © 2017 Martínez-Raudales et al.

  6. The influence of boundary features on grassland-edge communities of Alta Murgia

    OpenAIRE

    Cassano, Stefania; Alignier, Audrey; Forte, Luigi; Labadessa, Rocco; Mairota, Paola

    2016-01-01

    Many studies suggest the importance of boundary features on plant community dynamics. Our aim was to investigate the influence of boundary features on edge plant assemblages in semi-natural dry grasslands. For this purpose we selected 16 grassland edges in the central portion of the Natura 2000 site Murgia Alta, in southeastern Italy. These sites were selected according to a combination of boundary features, i.e. the adjoining land use type (road or cereal crop), slope (grassland tilted towar...

  7. Advances in methods for identification and characterization of plant transporter function

    DEFF Research Database (Denmark)

    Larsen, Bo; Xu, Deyang; Halkier, Barbara Ann

    2017-01-01

    Transport proteins are crucial for cellular function at all levels. Numerous importers and exporters facilitate transport of a diverse array of metabolites and ions intra- and intercellularly. Identification of transporter function is essential for understanding biological processes at both......-based approaches. In this review, we highlight examples that illustrate how new technology and tools have advanced identification and characterization of plant transporter functions....

  8. Assessing the Effects of Grassland Management on Forage Production and Environmental Quality to Identify Paths to Ecological Intensification in Mountain Grasslands.

    Science.gov (United States)

    Loucougaray, Grégory; Dobremez, Laurent; Gos, Pierre; Pauthenet, Yves; Nettier, Baptiste; Lavorel, Sandra

    2015-11-01

    Ecological intensification in grasslands can be regarded as a process for increasing forage production while maintaining high levels of ecosystem functions and biodiversity. In the mountain Vercors massif, where dairy cattle farming is the main component of agriculture, how to achieve forage autonomy at farm level while sustaining environmental quality for tourism and local dairy products has recently stimulated local debate. As specific management is one of the main drivers of ecosystem functioning, we assessed the response of forage production and environmental quality at grassland scale across a wide range of management practices. We aimed to determine which components of management can be harnessed to better match forage production and environmental quality. We sampled the vegetation of 51 grasslands stratified across 13 grassland types. We assessed each grassland for agronomic and environmental properties, measuring forage production, forage quality, and indices based on the abundance of particular plant species such as timing flexibility, apiarian potential, and aromatic plants. Our results revealed an expected trade-off between forage production and environmental quality, notably by stressing the contrasts between sown and permanent grasslands. However, strong within-type variability in both production and environmental quality as well as in flexibility of timing of use suggests possible ways to improve this trade-off at grassland and farm scales. As achieving forage autonomy relies on increasing both forage production and grassland resilience, our results highlight the critical role of the ratio between sown and permanent grasslands as a major path for ecological intensification in mountain grasslands.

  9. Nuclear power plant transient identification using a neuro-fuzzy inference system

    International Nuclear Information System (INIS)

    Mol, Antonio Carlos de Abreu; Oliveira, Mauro Vitor de; Santos, Isaac Jose Antonio Luchetti dos; Carvalho, Paulo Victor Rodrigues de; Grecco, Claudio Henrique dos Santos; Auguto, Silas Cordeiro

    2005-01-01

    Transient identification in Nuclear Power Plant (NPP) is often a very hard task and may involve a great amount of human cognition. The early identification of unexpected departures from steady state behavior is an essential step for the operation, control and accident management in nuclear power plants. The basis for the identification of a change in the system is that different system faults and anomalies lead to different patterns of evolution of the involved process variables. During an abnormal event, the operator must monitor a great amount of information from the instruments, that represents a specific type of event. In this work, an approach for the identification of transients is presented, aiming at helping the operator to make a decision relative to the procedure to be followed in situations of accidents/transients at nuclear power plants. In this way, a diagnostic strategy based on hierarchical use artificial neural networks (ANN) for a first level transient diagnose. After the ANN has done a preliminary transient type identification, a fuzzy-logic system analyzes the results emitting reliability degree of it. In order to validate the method, a Nuclear Power Plant transient identification problem, comprising postulated accidents, is proposed. Noisy data was used to evaluate the method robustness. The results obtained reveal the ability of the method in dealing with dynamic identification of transients and its reliability degree. (author)

  10. Parameter identification of a BWR nuclear power plant model for use in optimal control

    International Nuclear Information System (INIS)

    Volf, K.

    1976-02-01

    The problem being considered is the modeling of a nuclear power plant for the development of an optimal control system of the plant. Current system identification concepts, combining input/output information with a-priori structural information are employed. Two of the known parameter identification methods i.e., a least squares method and a maximum likelihood technique, are studied as ways of parameter identification from measurement data. A low order state variable stochastic model of a BWR nuclear power plant is presented as an application of this approach. The model consists of a deterministic and a noise part. The deterministic part is formed by simplified modeling of the major plant dynamic phenomena. The moise part models the effects of input random disturbances to the deterministic part and additive measurement noise. Most of the model parameters are assumed to be initially unknown. They are identified using measurement data records. A detailed high order digital computer simulation is used to simulate plant dynamic behaviour since it is not conceivable for experimentation of this kind to be performed on the real nuclear power plant. The identification task consists in adapting the performance of the simple model to the data acquired from this plant simulation ensuring the applicability of the techniques to measurement data acquired directly from the plant. (orig.) [de

  11. Methods for evaluation of the invasibility of grasslands

    DEFF Research Database (Denmark)

    Strandberg, M. T.; Strandberg, B.; Erneberg, M.

    The number of non-native plant species in Danish dry acidic grasslands was positively correlated with the cover of disturbance in the form of molehills, anthills, mouseholes and erosion due trampling or digging by large herbivores/livestock. Natural disturbance in acidic grassland ecosystems...... not grazed by livestock therefore is important for the occurrence of non-native species, and probably also for the occurrence of a high native floristic diversity....

  12. No consistent effect of plant species richness on resistance to simulated climate change for above- or below-ground processes in managed grasslands.

    Science.gov (United States)

    Dormann, Carsten F; von Riedmatten, Lars; Scherer-Lorenzen, Michael

    2017-06-17

    Species richness affects processes and functions in many ecosystems. Since management of temperate grasslands is directly affecting species composition and richness, it can indirectly govern how systems respond to fluctuations in environmental conditions. Our aim in this study was to investigate whether species richness in managed grasslands can buffer the effects of drought and warming manipulations and hence increase the resistance to climate change. We established 45 plots in three regions across Germany, each with three different management regimes (pasture, meadow and mown pasture). We manipulated spring warming using open-top chambers and summer drought using rain-out shelters for 4 weeks. Measurements of species richness, above- and below-ground biomass and soil carbon and nitrogen concentrations showed significant but inconsistent differences among regions, managements and manipulations. We detected a three-way interaction between species richness, management and region, indicating that our study design was sensitive enough to detect even intricate effects. We could not detect a pervasive effect of species richness on biomass differences between treatments and controls, indicating that a combination of spring warming and summer drought effects on grassland systems are not consistently moderated by species richness. We attribute this to the relatively high number of species even at low richness levels, which already provides the complementarity required for positive biodiversity-ecosystem functioning relationships. A review of the literature also indicates that climate manipulations largely fail to show richness-buffering, while natural experiments do, suggesting that such manipulations are milder than reality or incur treatment artefacts.

  13. Molecular DNA identification of medicinal plants used by traditional healers in Malaysia.

    Science.gov (United States)

    Aziz, N A A; Ahmad, M I; Naim, D M

    2015-12-07

    Plants have been used throughout human history for food and medicine. However, many plants are toxic, and cannot easily be morphologically distinguished from non-toxic plants. DNA identification solves this problem and is widely used. Nonetheless, plant DNA barcode identification faces a number of challenges, and many studies have been conducted to find suitable barcodes. The present study was conducted to test the efficiency of commonly used primers, namely ITS2, rpoC1, and trnH-psbA, in order to find the best DNA barcode markers for the identification of medicinal plants in Malaysia. Fresh leaves from 12 medicinal plants that are commonly used by Malay traditional healers were collected from the Tropical Spice Garden, Pulau Pinang, and subjected to polymerase chain reaction amplification using ITS2, rpoC1, and trnH-psbA DNA markers. We found that trnH-psbA is the best DNA marker for the species-level identification of medicinal plants in Malaysia.

  14. Drosophila melanogaster "a potential model organism" for identification of pharmacological properties of plants/plant-derived components.

    Science.gov (United States)

    Panchal, Komal; Tiwari, Anand K

    2017-05-01

    Plants/plant-derived components have been used from ancient times to treat/cure several human diseases. Plants and their parts possess several chemical components that play the vital role in the improvement of human health and their life expectancy. Allopathic medicines have been playing a key role in the treatment of several diseases. Though allopathic medicines provide fast relief, long time consumption cause serious health concerns such as hyperallergic reactions, liver damage, etc. So, the study of medicinal plants which rarely cause any side effect is very important to mankind. Plants contain many health benefit properties like antioxidant, anti-aging, neuroprotective, anti-genotoxic, anti-mutagenic and bioinsecticidal activity. Thus, identification of pharmacological properties of plants/plant-derived components are of utmost importance to be explored. Several model organisms have been used to identify the pharmacological properties of the different plants or active components therein and Drosophila is one of them. Drosophila melanogaster "fruit fly" is a well understood, high-throughput model organism being used more than 110 years to study the different biological aspects related to the development and diseases. Most of the developmental and cell signaling pathways and ∼75% human disease-related genes are conserved between human and Drosophila. Using Drosophila, one can easily analyze the pharmacological properties of plants/plant-derived components by performing several assays available with flies such as survivorship, locomotor, antioxidant, cell death, etc. The current review focuses on the potential of Drosophila melanogaster for the identification of medicinal/pharmacological properties associated with plants/plant-derived components. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  15. A Rose by Any Other Name: Plant Identification Knowledge & Socio-Demographics.

    Directory of Open Access Journals (Sweden)

    Beth S Robinson

    Full Text Available Concern has been expressed over societal losses of plant species identification skills. These losses have potential implications for engagement with conservation issues, gaining human wellbeing benefits from biodiversity (such as those resulting from nature-based recreational activities, and early warning of the spread of problematic species. However, understanding of the prevailing level of species identification skills, and of its key drivers, remains poor. Here, we explore socio-demographic factors influencing plant identification knowledge and ability to classify plants as native or non-native, employing a novel method of using real physical plants, rather than photographs or illustrations. We conducted face-to-face surveys at three different sites chosen to capture respondents with a range of socio-demographic circumstances, in Cornwall, UK. We found that survey participants correctly identified c.60% of common plant species, were significantly worse at naming non-native than native plants, and that less than 20% of people recognised Japanese knotweed Fallopia japonica, which is a widespread high profile invasive non-native in the study region. Success at naming plants was higher if participants were female, a member of at least one environmental, conservation or gardening organisation, in an older age group (than the base category of 18-29 years, or a resident (rather than visitor of the study area. Understanding patterns of variation in plant identification knowledge can inform the development of education and engagement strategies, for example, by targeting sectors of society where knowledge is lowest. Furthermore, greater understanding of general levels of identification of problematic invasive non-native plants can guide awareness and education campaigns to mitigate their impacts.

  16. Soil communities promote temporal stability and species asynchrony in experimental grassland communities

    NARCIS (Netherlands)

    Pellkofer, Sarah; Van Der Heijden, Marcel G A; Schmid, Bernhard; Wagg, Cameron

    2016-01-01

    Background Over the past two decades many studies have demonstrated that plant species diversity promotes primary productivity and stability in grassland ecosystems. Additionally, soil community characteristics have also been shown to influence the productivity and composition of plant communities,

  17. Computational identification of candidate nucleotide cyclases in higher plants

    KAUST Repository

    Wong, Aloysius Tze; Gehring, Christoph A

    2013-01-01

    In higher plants guanylyl cyclases (GCs) and adenylyl cyclases (ACs) cannot be identified using BLAST homology searches based on annotated cyclic nucleotide cyclases (CNCs) of prokaryotes, lower eukaryotes, or animals. The reason is that CNCs

  18. Identification of nuclear plant temperatures. Feedback parameters using experimental data

    International Nuclear Information System (INIS)

    Abdel Hamid, Sayed.

    1981-09-01

    This work is concerned with the identification of the fuel and moderator reactivity feedback coefficients of a Pressurized Water Reactor (PWR) using actual measurements. The main aim of this study is to examine the possibility to use a simplified model representing the reactor dynamics, which can be simulated on minicomputer and to supply an identification algorithm to get the feedback coefficients of PWR. The theoretical model of a PWR is built from the space independent reactor kinetics equation associated with six delayed neutron groups equations, as well as twelve equations describe the heat balance for the fuel and the moderator inside the reactor core, assuming that the core is composed from six successive axial zones. The reactor is externally perturbed by moving its control rods, and the corresponding changes in power and temperatures are recorded. The mathematical model has been solved numerically using fifth order Runge-Kutta integration technique by special developed package using Solar 16-40 computer (64 K memory size). As an identification algorithm, the Nelder-Mead Simplex method has been used to minimize the sum of the squares of the differences between measured and calculated reactor power. Hence, the feedback coefficients have been identified from off-line calculations

  19. Homogenization of the soil surface following fire in semiarid grasslands

    Science.gov (United States)

    Carleton S. White

    2011-01-01

    Semiarid grasslands accumulate soil beneath plant "islands" that are raised above bare interspaces. This fine-scale variation in microtopographic relief is plant-induced and is increased with shrub establishment. Research found that fire-induced water repellency enhanced local-scale soil erosion that reduced variation in microtopographic relief, suggesting...

  20. Hazard Identification, Risk Assessment and Risk Control (HIRARC Accidents at Power Plant

    Directory of Open Access Journals (Sweden)

    Ahmad Asmalia Che

    2016-01-01

    Full Text Available Power plant had a reputation of being one of the most hazardous workplace environments. Workers in the power plant face many safety risks due to the nature of the job. Although power plants are safer nowadays since the industry has urged the employer to improve their employees’ safety, the employees still stumble upon many hazards thus accidents at workplace. The aim of the present study is to investigate work related accidents at power plants based on HIRARC (Hazard Identification, Risk Assessment and Risk Control process. The data were collected at two coal-fired power plant located in Malaysia. The finding of the study identified hazards and assess risk relate to accidents occurred at the power plants. The finding of the study suggested the possible control measures and corrective actions to reduce or eliminate the risk that can be used by power plant in preventing accidents from occurred

  1. Genetic Programming for Medicinal Plant Family Identification System

    Directory of Open Access Journals (Sweden)

    Indra Laksmana

    2014-11-01

    Full Text Available Information about medicinal plants that is available in text documents is generally quite easy to access, however, one needs some efforts to use it. This research was aimed at utilizing crucial information taken from a text document to identify the family of several species of medicinal plants using a heuristic approach, i.e. genetic programming. Each of the species has its unique features. The genetic program puts the characteristics or special features of each family into a tree form. There are a number of processes involved in the investigated method, i.e. data acquisition, booleanization, grouping of training and test data, evaluation, and analysis. The genetic program uses a training process to select the best individual, initializes a generate-rule process to create several individuals and then executes a fitness evaluation. The next procedure is a genetic operation process, which consists of tournament selection to choose the best individual based on a fitness value, the crossover operation and the mutation operation. These operations have the purpose of complementing the individual. The best individual acquired is the expected solution, which is a rule for classifying medicinal plants. This process produced three rules, one for each plant family, displaying a feature structure that distinguishes each of the families from each other. The genetic program then used these rules to identify the medicinal plants, achieving an average accuracy of 86.47%.

  2. Optimizing learning of scientific category knowledge in the classroom: the case of plant identification.

    Science.gov (United States)

    Kirchoff, Bruce K; Delaney, Peter F; Horton, Meg; Dellinger-Johnston, Rebecca

    2014-01-01

    Learning to identify organisms is extraordinarily difficult, yet trained field biologists can quickly and easily identify organisms at a glance. They do this without recourse to the use of traditional characters or identification devices. Achieving this type of recognition accuracy is a goal of many courses in plant systematics. Teaching plant identification is difficult because of variability in the plants' appearance, the difficulty of bringing them into the classroom, and the difficulty of taking students into the field. To solve these problems, we developed and tested a cognitive psychology-based computer program to teach plant identification. The program incorporates presentation of plant images in a homework-based, active-learning format that was developed to stimulate expert-level visual recognition. A controlled experimental test using a within-subject design was performed against traditional study methods in the context of a college course in plant systematics. Use of the program resulted in an 8-25% statistically significant improvement in final exam scores, depending on the type of identification question used (living plants, photographs, written descriptions). The software demonstrates how the use of routines to train perceptual expertise, interleaved examples, spaced repetition, and retrieval practice can be used to train identification of complex and highly variable objects. © 2014 B. K. Kirchoff et al. CBE—Life Sciences Education © 2014 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  3. Flower resource and land management drives hoverfly communities and bee abundance in seminatural and agricultural grasslands.

    Science.gov (United States)

    Lucas, Andrew; Bull, James C; de Vere, Natasha; Neyland, Penelope J; Forman, Dan W

    2017-10-01

    Pollination is a key ecosystem service, and appropriate management, particularly in agricultural systems, is essential to maintain a diversity of pollinator guilds. However, management recommendations frequently focus on maintaining plant communities, with the assumption that associated invertebrate populations will be sustained. We tested whether plant community, flower resources, and soil moisture would influence hoverfly (Syrphidae) abundance and species richness in floristically-rich seminatural and floristically impoverished agricultural grassland communities in Wales (U.K.) and compared these to two Hymenoptera genera, Bombus, and Lasioglossum . Interactions between environmental variables were tested using generalized linear modeling, and hoverfly community composition examined using canonical correspondence analysis. There was no difference in hoverfly abundance, species richness, or bee abundance, between grassland types. There was a positive association between hoverfly abundance, species richness, and flower abundance in unimproved grasslands. However, this was not evident in agriculturally improved grassland, possibly reflecting intrinsically low flower resource in these habitats, or the presence of plant species with low or relatively inaccessible nectar resources. There was no association between soil moisture content and hoverfly abundance or species richness. Hoverfly community composition was influenced by agricultural improvement and the amount of flower resource. Hoverfly species with semiaquatic larvae were associated with both seminatural and agricultural wet grasslands, possibly because of localized larval habitat. Despite the absence of differences in hoverfly abundance and species richness, distinct hoverfly communities are associated with marshy grasslands, agriculturally improved marshy grasslands, and unimproved dry grasslands, but not with improved dry grasslands. Grassland plant community cannot be used as a proxy for pollinator

  4. Identification of a Plant Phytosterol with Toxicity against Arthropod Pests

    Directory of Open Access Journals (Sweden)

    J.R.M. Thacker

    1999-06-01

    Full Text Available A crude plant extract that was toxic to spider mites in a leaf dip bioassay was subjected to detailed chemical analysis using chromatographic and spectroscopic techniques, The analyses revealed that the major active chemical was probably fl-sitosterol-3-glucostdc, a known phytosterol. The literature indicates that this chemical has been identified in a number of plant species and that it has been tested for utility in a number of medical therapies. It has not so far been assayed for the control of arthropod posts, the data indicate that this compound may be of use in the control of pest species, especially spider mites.

  5. Phytoliths as Emerging Taxonomic Tools for Identification of Plants: An Overview

    Directory of Open Access Journals (Sweden)

    Sheikh Abdul Shakoor

    2014-01-01

    Full Text Available In the recent advancements in identification of plant species, phytoliths have found an immense role in the identification of plants at different levels of taxonomic hierarchy. Many plant groups are known to accumulate silica in solid form in and between the cells and tissues and hence create the structures commonly known as phytoliths. These phytoliths create replicas of the structures where they are deposited. The shapes of phytolith replicas, their size dimensions (morphometric parameters, surface features (ornamentation, distribution, and orientation pattern in epidermal layers of vegetative and reproductive structures as well as their frequency are highly important for characterization of species. Monocotyledonous families particularly the family Poaceae (Gramineae are known to produce diverse phytolith types that can serve as diagnostic markers for characterization of different taxa at different levels of taxonomic hierarchy. The present paper highlights the importance of phytoliths in taxonomic analysis of plants particularly in the family Poaceae.

  6. Identification and primary characterization of a plant antimicrobial ...

    African Journals Online (AJOL)

    Then an agar-overlay method using fully separated proteins on sodium dodecyl sulphate-polyacryliamide gel electrophoresis (SDS-PAGE) gels was used for initial determination and primary characterization of active putative defensins in the plant seeds. Clear and remarkable zones of inhibition in a region corresponding to ...

  7. DNA barcoding of medicinal plant material for identification

    Science.gov (United States)

    Because of the increasing demand for herbal remedies and for authentication of the source material, it is vital to provide a single database containing information about authentic plant materials and their potential adulterants. The database should provide DNA barcodes for data retrieval and similar...

  8. The identification and remote detection of alien invasive plants in ...

    African Journals Online (AJOL)

    Kabir Peerbhay

    remote sensing techniques offer a synoptic rapid approach for detecting and mapping weeds ... plant substrates, soil properties, the microclimate, water relations, density and height of .... Additionally, a precise weed detection system ..... complexities when detecting IAP species for real-time monitoring and decision making.

  9. Illustrated Plant Identification Keys: An Interactive Tool to Learn Botany

    Science.gov (United States)

    Silva, Helena; Pinho, Rosa; Lopes, Lisia; Nogueira, Antonio J. A.; Silveira, Paulo

    2011-01-01

    An Interactive Dichotomous Key (IDK) for 390 "taxa" of vascular plants from the Ria de Aveiro, available on a website, was developed to help teach botany to school and universitary students. This multimedia tool includes several links to Descriptive and Illustrated Glossaries. Questionnaires answered by high-school and undergraduate students about…

  10. Identification of plant genes for abiotic stress resistance

    NARCIS (Netherlands)

    Dixit, S.A.

    2008-01-01

    As water and salt stresses occur frequently and can affect many habitats, plants have developed several strategies to cope with these challenges: either adaptation mechanisms, which allow them to survive the adverse conditions, or specific growth habits to avoid stress conditions. Stress-tolerant

  11. Chromosome identification for the carnivorous plant Genlisea margaretae

    Czech Academy of Sciences Publication Activity Database

    Tran, T.D.; Šimková, Hana; Schmidt, R.; Doležel, Jaroslav; Schubert, I.; Fuchs, J.

    2017-01-01

    Roč. 126, č. 3 (2017), s. 389-397 ISSN 0009-5915 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : BACs * Genlisea * Karyotyping * Multicolor fluorescence in situ hybridization (mcFISH) * Reprobing Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Plant sciences, botany Impact factor: 4.414, year: 2016

  12. AIRBORNE HYPERSPECTRAL IDENTIFICATION OF INVASIVE AND OPPORTUNISTIC WETLANDS PLANT SPECIES

    Science.gov (United States)

    Coastal wetlands are among the most fragmented and disturbed ecosystems and the Great Lakes are no exception. One possible result is the observed increase in the presence and dominance of invasive and other opportunistic plant species, such as the common reed (Phragmites australi...

  13. Molecular Identification of Microorganisms Associated to the Rhizosphere of Vanilla Plants in Colombia

    OpenAIRE

    Claudia Lucía Álvarez López; Nelson Walter Osorio Vega; Mauricio Alejandro Marín Montoya

    2013-01-01

    The cultivation of vanilla (Vanilla planifolia) is highly promising in Colombia, but more research is needed on its agronomical management and beneficial microorganisms that grow associated to its rhizosphere, on which the plant depends for its nutrition and growth. This study involved the identification of microorganisms associated to the rhizosphere of vanilla plants in a crop located in Sopetrán, Colombia. The microbes were isolated in selective media for functional groups such as cellulol...

  14. Identification and assay of the flavonoids in medicinal plants with hepatoprotective action

    OpenAIRE

    Cojocaru-Toma M.

    2015-01-01

    The article describes the identification and assay of the flavonoids in medicinal plants with hepatoprotective action, harvested as a culture at the Cultivation Center of the Medicinal Plants within State University of Medicine and Pharmacy „Nicolae Testemițanu” from the Republic of Moldova, using Pharmacopoeia methods. The flavonoids, found in the examined medicinal product, are responsible for hepatoprotective activity due to antioxidant activity, exhibited by neutralizing free radicals. Th...

  15. Effect of degradation intensity on grassland ecosystem services in the alpine region of Qinghai-Tibetan Plateau, China.

    Directory of Open Access Journals (Sweden)

    Lu Wen

    Full Text Available The deterioration of alpine grassland has great impact on ecosystem services in the alpine region of Qinghai-Tibetan Plateau. However, the effect of grassland degradation on ecosystem services and the consequence of grassland deterioration on economic loss still remains a mystery. So, in this study, we assessed four types of ecosystem services following the Millennium Ecosystem Assessment classification, along a degradation gradient. Five sites of alpine grassland at different levels of degradation were investigated in Guoluo Prefecture of Qinghai Province, China. The species composition, aboveground biomass, soil total organic carbon (TOC, and soil total nitrogen (TN were tested to evaluate major ecological services of the alpine grassland. We estimated the value of primary production, carbon storage, nitrogen recycling, and plant diversity. The results show the ecosystem services of alpine grassland varied along the degradation gradient. The ecosystem services of degraded grassland (moderate, heavy and severe were all significantly lower than non-degraded grassland. Interestingly, the lightly degraded grassland provided more economic benefit from carbon maintenance and nutrient sequestration compared to non-degraded. Due to the destruction of the alpine grassland, the economic loss associated with decrease of biomass in 2008 was $198/ha. Until 2008, the economic loss caused by carbon emissions and nitrogen loss on severely degraded grassland was up to $8 033/ha and $13 315/ha, respectively. Urgent actions are required to maintain or promote the ecosystem services of alpine grassland in the Qinghai-Tibetan Plateau.

  16. Effect of degradation intensity on grassland ecosystem services in the alpine region of Qinghai-Tibetan Plateau, China.

    Science.gov (United States)

    Wen, Lu; Dong, Shikui; Li, Yuanyuan; Li, Xiaoyan; Shi, Jianjun; Wang, Yanlong; Liu, Demei; Ma, Yushou

    2013-01-01

    The deterioration of alpine grassland has great impact on ecosystem services in the alpine region of Qinghai-Tibetan Plateau. However, the effect of grassland degradation on ecosystem services and the consequence of grassland deterioration on economic loss still remains a mystery. So, in this study, we assessed four types of ecosystem services following the Millennium Ecosystem Assessment classification, along a degradation gradient. Five sites of alpine grassland at different levels of degradation were investigated in Guoluo Prefecture of Qinghai Province, China. The species composition, aboveground biomass, soil total organic carbon (TOC), and soil total nitrogen (TN) were tested to evaluate major ecological services of the alpine grassland. We estimated the value of primary production, carbon storage, nitrogen recycling, and plant diversity. The results show the ecosystem services of alpine grassland varied along the degradation gradient. The ecosystem services of degraded grassland (moderate, heavy and severe) were all significantly lower than non-degraded grassland. Interestingly, the lightly degraded grassland provided more economic benefit from carbon maintenance and nutrient sequestration compared to non-degraded. Due to the destruction of the alpine grassland, the economic loss associated with decrease of biomass in 2008 was $198/ha. Until 2008, the economic loss caused by carbon emissions and nitrogen loss on severely degraded grassland was up to $8 033/ha and $13 315/ha, respectively. Urgent actions are required to maintain or promote the ecosystem services of alpine grassland in the Qinghai-Tibetan Plateau.

  17. In silico identification and analysis of phytoene synthase genes in plants.

    Science.gov (United States)

    Han, Y; Zheng, Q S; Wei, Y P; Chen, J; Liu, R; Wan, H J

    2015-08-14

    In this study, we examined phytoene synthetase (PSY), the first key limiting enzyme in the synthesis of carotenoids and catalyzing the formation of geranylgeranyl pyrophosphate in terpenoid biosynthesis. We used known amino acid sequences of the PSY gene in tomato plants to conduct a genome-wide search and identify putative candidates in 34 sequenced plants. A total of 101 homologous genes were identified. Phylogenetic analysis revealed that PSY evolved independently in algae as well as monocotyledonous and dicotyledonous plants. Our results showed that the amino acid structures exhibited 5 motifs (motifs 1 to 5) in algae and those in higher plants were highly conserved. The PSY gene structures showed that the number of intron in algae varied widely, while the number of introns in higher plants was 4 to 5. Identification of PSY genes in plants and the analysis of the gene structure may provide a theoretical basis for studying evolutionary relationships in future analyses.

  18. Rapid Identification and Verification of Indirubin-Containing Medicinal Plants

    OpenAIRE

    Hu, Zhigang; Tu, Yuan; Xia, Ye; Cheng, Peipei; Sun, Wei; Shi, Yuhua; Guo, Licheng; He, Haibo; Xiong, Chao; Chen, Shilin; Zhang, Xiuqiao

    2015-01-01

    Indirubin, one of the key components of medicinal plants including Isatis tinctoria, Polygonum tinctorium, and Strobilanthes cusia, possesses great medicinal efficacy in the treatment of chronic myelocytic leukemia (CML). Due to misidentification and similar name, materials containing indirubin and their close relatives frequently fall prey to adulteration. In this study, we selected an internal transcribed spacer 2 (ITS2) for distinguishing these indirubin-containing species from five of the...

  19. IDENTIFICATION AND AUTHENTICATION OF DRY SAMPLES OF SOME MEDICINAL PLANTS USING LEAF EPIDERMAL FEATURES AS MARKER

    Directory of Open Access Journals (Sweden)

    Abdullahi Alanamu ABDULRAHAMAN

    2016-06-01

    Full Text Available Herbal medicine is the oldest and still the most widely used system of medicine in the world today and they are made exclusively from plants. However, most of these medicines or drugs are adulterated due to lack of proper identification of the plant samples. Method of checking adulteration of drug plants is the main focus of this study. The identification and authentication of dry samples of some medicinal plants were carried out using anatomical features. Twenty-five (25 plants materials were collected in Ibadan and Ilorin, Nigeria. The plants studied include Azardiracta indica, Newboudia leavis, Polyalthia longifolia, Cymbopogon citratus, Anarcardium occidentalis, Nicotiana tobbaccum, Jatropha curcas, Chromoleana odorata, Mangifera indica, Terminalia catappa, Ocimum gratisimum, Morus messosygia, Morinda lucida, Psidium guajava, Vitellaria paradoxa, Annona senegalensis, Vernonia amygdalina, Gliricidium sepium, Ravoulvia vomitora, Telferia occindentalis Citrus aurantifolia, C. limon, C. paradisi and C. sinensis. Leaf epidermal anatomy of these selected plants showed no major variations in stomatal complex types, frequency, size and shape of stomatal cells, epidermal cell wall and trichomes between fresh and dry samples. The variations that occur were between different species but not within species. Leaf epidermal anatomy, therefore, proved to be a significant tool for resolution of taxonomic confusion of dried samples of these plants.

  20. Peptidomic Identification of Cysteine-Rich Peptides from Plants.

    Science.gov (United States)

    Hemu, Xinya; Serra, Aida; Darwis, Dina A; Cornvik, Tobias; Sze, Siu Kwan; Tam, James P

    2018-01-01

    Plant cysteine-rich peptides (CRPs) constitute a majority of plant-derived peptides with high molecular diversity. This protocol describes a rapid and efficient peptidomic approach to identify a whole spectrum of CRPs in a plant extract and decipher their molecular diversity and bioprocessing mechanism. Cyclotides from C. ternatea are used as the model CRPs to demonstrate our methodology. Cyclotides exist naturally in both cyclic and linear forms, although the linear forms (acyclotide) are generally present at much lower concentrations. Both cyclotides and acyclotides require linearization of their backbone prior to fragmentation and sequencing. A novel and practical three-step chemoenzymatic treatment was developed to linearize and distinguish both forms: (1) N-terminal acetylation that pre-labels the acyclotides; (2) conversion of Cys into pseudo-Lys through aziridine-mediated S-alkylation to reduce disulfide bonds and to increase the net charge of peptides; and (3) opening of cyclic backbones by the novel asparaginyl endopeptidase butelase 2 that cleaves at the native bioprocessing site. The treated peptides are subsequently analyzed by liquid chromatography coupled to mass spectrometry using electron transfer dissociation fragmentation and sequences are identified by matching the MS/MS spectra directly with the transcriptomic database.

  1. C-mii: a tool for plant miRNA and target identification.

    Science.gov (United States)

    Numnark, Somrak; Mhuantong, Wuttichai; Ingsriswang, Supawadee; Wichadakul, Duangdao

    2012-01-01

    MicroRNAs (miRNAs) have been known to play an important role in several biological processes in both animals and plants. Although several tools for miRNA and target identification are available, the number of tools tailored towards plants is limited, and those that are available have specific functionality, lack graphical user interfaces, and restrict the number of input sequences. Large-scale computational identifications of miRNAs and/or targets of several plants have been also reported. Their methods, however, are only described as flow diagrams, which require programming skills and the understanding of input and output of the connected programs to reproduce. To overcome these limitations and programming complexities, we proposed C-mii as a ready-made software package for both plant miRNA and target identification. C-mii was designed and implemented based on established computational steps and criteria derived from previous literature with the following distinguishing features. First, software is easy to install with all-in-one programs and packaged databases. Second, it comes with graphical user interfaces (GUIs) for ease of use. Users can identify plant miRNAs and targets via step-by-step execution, explore the detailed results from each step, filter the results according to proposed constraints in plant miRNA and target biogenesis, and export sequences and structures of interest. Third, it supplies bird's eye views of the identification results with infographics and grouping information. Fourth, in terms of functionality, it extends the standard computational steps of miRNA target identification with miRNA-target folding and GO annotation. Fifth, it provides helper functions for the update of pre-installed databases and automatic recovery. Finally, it supports multi-project and multi-thread management. C-mii constitutes the first complete software package with graphical user interfaces enabling computational identification of both plant miRNA genes and mi

  2. Applying a neuro-fuzzy approach for transient identification in a nuclear power plant

    International Nuclear Information System (INIS)

    Costa, Rafael G.; Mol, Antonio C.A.; Pereira, Claudio M.N.A.; Carvalho, Paulo V.R.

    2009-01-01

    Transient identification in Nuclear Power Plant (NPP) is often a very hard task and may involve a great amount of human cognition. The early identification of unexpected departures from steady state behavior is an essential step for the operation, control and accident management in NPPs. The bases for the transient identification relay on the evidence that different system faults and anomalies lead to different pattern evolution in the involved process variables. During an abnormal event, the operator must monitor a great amount of information from the instruments that represents a specific type of event. Several systems based on specialist systems, neural networks, and fuzzy logic have been developed for transient identification. In the work, we investigate the possibility of using a Neuro-Fuzzy modeling tool for efficient transient identification, aiming to helping the operator crew to take decisions relative to the procedure to be followed in situations of accidents/transients at NPPs. The proposed system uses artificial neural networks (ANN) as first level transient diagnostic. After the ANN has done the preliminary transient type identification, a fuzzy-logic system analyzes the results emitting reliability degree of it. A preliminary evaluation of the developed system was made at the Human-System Interface Laboratory (LABIHS). The obtained results show that the system can help the operators to take decisions during transients/accidents in the plant. (author)

  3. Classification of Grassland Successional Stages Using Airborne Hyperspectral Imagery

    Directory of Open Access Journals (Sweden)

    Thomas Möckel

    2014-08-01

    Full Text Available Plant communities differ in their species composition, and, thus, also in their functional trait composition, at different stages in the succession from arable fields to grazed grassland. We examine whether aerial hyperspectral (414–2501 nm remote sensing can be used to discriminate between grazed vegetation belonging to different grassland successional stages. Vascular plant species were recorded in 104.1 m2 plots on the island of Öland (Sweden and the functional properties of the plant species recorded in the plots were characterized in terms of the ground-cover of grasses, specific leaf area and Ellenberg indicator values. Plots were assigned to three different grassland age-classes, representing 5–15, 16–50 and >50 years of grazing management. Partial least squares discriminant analysis models were used to compare classifications based on aerial hyperspectral data with the age-class classification. The remote sensing data successfully classified the plots into age-classes: the overall classification accuracy was higher for a model based on a pre-selected set of wavebands (85%, Kappa statistic value = 0.77 than one using the full set of wavebands (77%, Kappa statistic value = 0.65. Our results show that nutrient availability and grass cover differences between grassland age-classes are detectable by spectral imaging. These techniques may potentially be used for mapping the spatial distribution of grassland habitats at different successional stages.

  4. CHIP: Commodity based Hazard Identification Protocol for emerging diseases in plants and animals

    NARCIS (Netherlands)

    Bremmer, J.; Swanenburg, M.; Galen, van M.A.; Hoek, Maarten; Rau, M.L.; Hennen, W.H.G.J.; Benninga, J.; Ge, L.; Breukers, M.L.H.

    2012-01-01

    This project comprised the development of a commodity-based hazard identification protocol for biological hazards in plants and animals as a decision support tree programmed in Excel. The content of the decision tree is based on the results of a systematic review of pest and pathogen

  5. The Eurasian Dry Grassland Group (EDGG in 2016–2017

    Directory of Open Access Journals (Sweden)

    Venn Stephen

    2018-06-01

    Full Text Available This report summarizes the activities and achievements of the Eurasian Dry Grassland Group (EDGG from mid-2016 through to the end of 2017. During this period, the 13th Eurasian Grassland Conference took place in Sighişoara, Romania, and the 14th conference was held in Riga, Latvia. The 10th EDGG Field Workshop on Biodiversity patterns across a precipitation gradient in the Central Apennine mountains was conducted in the Central Apennines, Italy, this time in addition to multi-scale sampling of vascular plants, bryophytes and lichens, also including one animal group (leaf hoppers. Apart from the quarterly issues of its own electronic journal (Bulletin of the Eurasian Dry Grassland Group, EDGG also finalised five grassland-related Special Features/Issues during the past 1.5 years in the following international journals: Applied Vegetation Science, Biodiversity and Conservation, Phytocoenologia, Tuexenia and Hacquetia. Beyond that, EDGG facilitated various national and supra-national vegetationplot databases of grasslands and established its own specialised database for standardised multi-scale plot data of Palaearctic grasslands (GrassPlot.

  6. Plant functional traits and canopy structure control the relationship between photosynthetic CO2 uptake and far-red sun-induced fluorescence in a Mediterranean grassland under different nutrient availability.

    Science.gov (United States)

    Migliavacca, Mirco; Perez-Priego, Oscar; Rossini, Micol; El-Madany, Tarek S; Moreno, Gerardo; van der Tol, Christiaan; Rascher, Uwe; Berninger, Anna; Bessenbacher, Verena; Burkart, Andreas; Carrara, Arnaud; Fava, Francesco; Guan, Jin-Hong; Hammer, Tiana W; Henkel, Kathrin; Juarez-Alcalde, Enrique; Julitta, Tommaso; Kolle, Olaf; Martín, M Pilar; Musavi, Talie; Pacheco-Labrador, Javier; Pérez-Burgueño, Andrea; Wutzler, Thomas; Zaehle, Sönke; Reichstein, Markus

    2017-05-01

    Sun-induced fluorescence (SIF) in the far-red region provides a new noninvasive measurement approach that has the potential to quantify dynamic changes in light-use efficiency and gross primary production (GPP). However, the mechanistic link between GPP and SIF is not completely understood. We analyzed the structural and functional factors controlling the emission of SIF at 760 nm (F 760 ) in a Mediterranean grassland manipulated with nutrient addition of nitrogen (N), phosphorous (P) or nitrogen-phosphorous (NP). Using the soil-canopy observation of photosynthesis and energy (SCOPE) model, we investigated how nutrient-induced changes in canopy structure (i.e. changes in plant forms abundance that influence leaf inclination distribution function, LIDF) and functional traits (e.g. N content in dry mass of leaves, N%, Chlorophyll a+b concentration (Cab) and maximum carboxylation capacity (V cmax )) affected the observed linear relationship between F 760 and GPP. We conclude that the addition of nutrients imposed a change in the abundance of different plant forms and biochemistry of the canopy that controls F 760 . Changes in canopy structure mainly control the GPP-F 760 relationship, with a secondary effect of Cab and V cmax . In order to exploit F 760 data to model GPP at the global/regional scale, canopy structural variability, biodiversity and functional traits are important factors that have to be considered. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  7. Trichoderma Biofertilizer Links to Altered Soil Chemistry, Altered Microbial Communities, and Improved Grassland Biomass

    Directory of Open Access Journals (Sweden)

    Fengge Zhang

    2018-04-01

    Full Text Available In grasslands, forage and livestock production results in soil nutrient deficits as grasslands typically receive no nutrient inputs, leading to a loss of grassland biomass. The application of mature compost has been shown to effectively increase grassland nutrient availability. However, research on fertilization regime influence and potential microbial ecological regulation mechanisms are rarely conducted in grassland soil. We conducted a two-year experiment in meadow steppe grasslands, focusing on above- and belowground consequences of organic or Trichoderma biofertilizer applications and potential soil microbial ecological mechanisms underlying soil chemistry and microbial community responses. Grassland biomass significantly (p = 0.019 increased following amendment with 9,000 kg ha−1 of Trichoderma biofertilizer (composted cattle manure + inoculum compared with other assessed organic or biofertilizer rates, except for BOF3000 (fertilized with 3,000 kg ha−1 biofertilizer. This rate of Trichoderma biofertilizer treatment increased soil antifungal compounds that may suppress pathogenic fungi, potentially partially responsible for improved grassland biomass. Nonmetric multidimensional scaling (NMDS revealed soil chemistry and fungal communities were all separated by different fertilization regime. Trichoderma biofertilizer (9,000 kg ha−1 increased relative abundances of Archaeorhizomyces and Trichoderma while decreasing Ophiosphaerella. Trichoderma can improve grassland biomass, while Ophiosphaerella has the opposite effect as it may secrete metabolites causing grass necrosis. Correlations between soil properties and microbial genera showed plant-available phosphorus may influence grassland biomass by increasing Archaeorhizomyces and Trichoderma while reducing Ophiosphaerella. According to our structural equation modeling (SEM, Trichoderma abundance was the primary contributor to aboveground grassland biomass. Our results suggest Trichoderma

  8. Trichoderma Biofertilizer Links to Altered Soil Chemistry, Altered Microbial Communities, and Improved Grassland Biomass.

    Science.gov (United States)

    Zhang, Fengge; Huo, Yunqian; Cobb, Adam B; Luo, Gongwen; Zhou, Jiqiong; Yang, Gaowen; Wilson, Gail W T; Zhang, Yingjun

    2018-01-01

    In grasslands, forage and livestock production results in soil nutrient deficits as grasslands typically receive no nutrient inputs, leading to a loss of grassland biomass. The application of mature compost has been shown to effectively increase grassland nutrient availability. However, research on fertilization regime influence and potential microbial ecological regulation mechanisms are rarely conducted in grassland soil. We conducted a two-year experiment in meadow steppe grasslands, focusing on above- and belowground consequences of organic or Trichoderma biofertilizer applications and potential soil microbial ecological mechanisms underlying soil chemistry and microbial community responses. Grassland biomass significantly ( p = 0.019) increased following amendment with 9,000 kg ha -1 of Trichoderma biofertilizer (composted cattle manure + inoculum) compared with other assessed organic or biofertilizer rates, except for BOF3000 (fertilized with 3,000 kg ha -1 biofertilizer). This rate of Trichoderma biofertilizer treatment increased soil antifungal compounds that may suppress pathogenic fungi, potentially partially responsible for improved grassland biomass. Nonmetric multidimensional scaling (NMDS) revealed soil chemistry and fungal communities were all separated by different fertilization regime. Trichoderma biofertilizer (9,000 kg ha -1 ) increased relative abundances of Archaeorhizomyces and Trichoderma while decreasing Ophiosphaerella . Trichoderma can improve grassland biomass, while Ophiosphaerella has the opposite effect as it may secrete metabolites causing grass necrosis. Correlations between soil properties and microbial genera showed plant-available phosphorus may influence grassland biomass by increasing Archaeorhizomyces and Trichoderma while reducing Ophiosphaerella . According to our structural equation modeling (SEM), Trichoderma abundance was the primary contributor to aboveground grassland biomass. Our results suggest Trichoderma

  9. An application of multilevel flow modelling method for nuclear plant state identification

    International Nuclear Information System (INIS)

    Businaro, T.; Di Lorenzo, A.; Meo, G.B.; Rabbani, M.I.; Rubino, E.

    1986-01-01

    With the advent of advanced digital techniques it has been rendered possible, necessity of which has long since been recognised, to develop a computer based man-machine interface and hance an expert system based on knowledge based decision making for operator support in the control rooms of nuclear plants. The Multilevel Flow Modelling method developed at RISO Laboratories, Denmark, has been applied in the present experiment to model Italian PEC reactor and to verify applicability of this method in plant state identification. In MFM method functional structure of a process plant is described in terms of a set of interrelated mass and energy flow structures on different levels of physical aggregation

  10. The identification of plant lectins with mucosal adjuvant activity

    Science.gov (United States)

    Lavelle, E C; Grant, G; Pusztai, A; Pfüller, U; O'hagan, D T

    2001-01-01

    To date, the most potent mucosal vaccine adjuvants to be identified have been bacterial toxins. The present data demonstrate that the type 2 ribosome-inactivating protein (type 2 RIP), mistletoe lectin I (ML-I) is a strong mucosal adjuvant of plant origin. A number of plant lectins were investigated as intranasal (i.n.) coadjuvants for a bystander protein, ovalbumin (OVA). As a positive control, a potent mucosal adjuvant, cholera toxin (CT), was used. Co-administration of ML-I or CT with OVA stimulated high titres of OVA-specific serum immunoglobulin G (IgG) in addition to OVA-specific IgA in mucosal secretions. CT and ML-I were also strongly immunogenic, inducing high titres of specific serum IgG and specific IgA at mucosal sites. None of the other plant lectins investigated significantly boosted the response to co-administered OVA. Immunization with phytohaemagglutinin (PHA) plus OVA elicited a lectin-specific response but did not stimulate an enhanced response to OVA compared with the antigen alone. Intranasal delivery of tomato lectin (LEA) elicited a strong lectin-specific systemic and mucosal antibody response but only weakly potentiated the response to co-delivered OVA. In contrast, administration of wheatgerm agglutinin (WGA) or Ulex europaeus lectin 1 (UEA-I) with OVA stimulated a serum IgG response to OVA while the lectin-specific responses (particularly for WGA) were relatively low. Thus, there was not a direct correlation between immunogenicity and adjuvanticity although the strongest adjuvants (CT, ML-I) were also highly immunogenic. PMID:11168640

  11. Identification of Radioactive Pilot-Plant test requirements

    Energy Technology Data Exchange (ETDEWEB)

    Powell, W.J.; Riebling, E.F.

    1995-05-09

    Radioactive Pilot-Plant testing needs and alternatives are evaluated for enhanced Sludge Washing and High and Low-Level Vitrification efforts. Also investigated was instrument and equipment testing needs associated with the vitrification and retrieval process. The scope of this document is to record the existing March 1994 letter report for future use. A structured Kepner-Trego{trademark} decision analysis process was used to assist analysis of the testing needs. This analysis provided various combinations of laboratory and radioactive (hot) and cold pilot testing options associated with the above need areas. Recommendations for testing requirements were made.

  12. Identification of Radioactive Pilot-Plant test requirements

    International Nuclear Information System (INIS)

    Powell, W.J.; Riebling, E.F.

    1995-01-01

    Radioactive Pilot-Plant testing needs and alternatives are evaluated for enhanced Sludge Washing and High and Low-Level Vitrification efforts. Also investigated was instrument and equipment testing needs associated with the vitrification and retrieval process. The scope of this document is to record the existing March 1994 letter report for future use. A structured Kepner-Trego trademark decision analysis process was used to assist analysis of the testing needs. This analysis provided various combinations of laboratory and radioactive (hot) and cold pilot testing options associated with the above need areas. Recommendations for testing requirements were made

  13. Exacerbated grassland degradation and desertification in Central Asia during 2000-2014.

    Science.gov (United States)

    Zhang, Geli; Biradar, Chandrashekhar M; Xiao, Xiangming; Dong, Jinwei; Zhou, Yuting; Qin, Yuanwei; Zhang, Yao; Liu, Fang; Ding, Mingjun; Thomas, Richard J

    2018-03-01

    processes, this study provided reference information for identification of desertification hotspots to support further grassland degradation and desertification treatment, and the method could be useful to be extended to other regions. © 2017 by the Ecological Society of America.

  14. Molecular identification of microorganisms associated to the rhizosphere of vanilla plants in Colombia

    International Nuclear Information System (INIS)

    Alvarez Lopez, Claudia Lucia; Osorio Vega, Nelson Walter; Marin Montoya, Mauricio Alejandro

    2013-01-01

    The cultivation of vanilla (Vanilla planifolia) is highly promising in Colombia, but more research is needed on its agronomical management and beneficial microorganisms that grow associated to its rhizosphere, on which the plant depends for its nutrition and growth. This study involved the identification of microorganisms associated to the rhizosphere of vanilla plants in a crop located in Sopetran, Colombia. The microbes were isolated in selective media for functional groups such as cellulolytic, proteolytic, inorganic and organic phosphate (phytate) solubilizers, and asymbiotic nitrogen fixing bacteria. After isolation and purification, 109 microbial isolates were obtained. DNA was extracted from 52 selected isolates for molecular identification based on its and 16s RDNA sequencing, for fungi and bacteria, respectively. The diversity of rhizosphere microorganisms found was significant. Bacteria such as Bacillus Megaterium, Pseudomonas koreensis and Acinetobacter sp., and the Fungus Plectosphaerella sp., may have a high potential to be used as biofertilizers to improve vanilla plant nutrition and growth.

  15. Identification of multivariate models for noise analysis of nuclear plant

    International Nuclear Information System (INIS)

    Zwingelstein, G.C.; Upadhyaya, B.R.

    1979-01-01

    During the normal operation of a pressurized water reactor, neutron noise analysis with multivariate autoregressive procedures in a valuable diagnostic tool to extract dynamic characteristics for incipient failure detection. The first part of the paper will describe in details the equations for estimating the multivariate autoregressive model matrices and the structure of various matrices. The matrices are estimated by solving a set of matrix operations, called Yule-Walker equations. The selection of optimal model order will also be discussed. Once the optimal parameter set is obtained, simple and fast calculations are used to determine the auto power spectral density, cross spectra, coherence function, phase. In addition the spectra may be decomposed into components being contributed from different noise sources. An application using neutron flux data collected on a nuclear plant will illustrate the efficiency of the method

  16. Identification, Characterization, and Palynology of High-Valued Medicinal Plants

    Directory of Open Access Journals (Sweden)

    Hina Fazal

    2013-01-01

    Full Text Available High-valued medicinal plants Achillea millefolium, Acorus calamus, Arnebia nobilis, Fumaria indica, Gymnema sylvestre, Origanum vulgare, Paeonia emodi, Peganum harmala, Psoralea corylifolia, Rauwolfia serpentina, and Vetiveria zizanioides were identified with the help of taxonomical markers and investigated for characterization and palynological studies. These parameters are used to analyze their quality, safety, and standardization for their safe use. Botanical description and crude drug description is intended for their quality assurance at the time of collection, commerce stages, manufacturing, and production. For this purpose the detailed morphology was studied and compared with the Flora of Pakistan and other available literatures. Here we reported the pollen grain morphology of Origanum vulgare, Paeonia emodi, Psoralea corylifolia, and Rauwolfia serpentina for the first time. Similarly the crude drug study of Gymnema sylvestre (leaf, Origanum vulgare (aerial parts, Paeonia emodi (tubers, and Peganum harmala (seeds was also carried out for the first time.

  17. Identification, characterization, and palynology of high-valued medicinal plants.

    Science.gov (United States)

    Fazal, Hina; Ahmad, Nisar; Haider Abbasi, Bilal

    2013-01-01

    High-valued medicinal plants Achillea millefolium, Acorus calamus, Arnebia nobilis, Fumaria indica, Gymnema sylvestre, Origanum vulgare, Paeonia emodi, Peganum harmala, Psoralea corylifolia, Rauwolfia serpentina, and Vetiveria zizanioides were identified with the help of taxonomical markers and investigated for characterization and palynological studies. These parameters are used to analyze their quality, safety, and standardization for their safe use. Botanical description and crude drug description is intended for their quality assurance at the time of collection, commerce stages, manufacturing, and production. For this purpose the detailed morphology was studied and compared with the Flora of Pakistan and other available literatures. Here we reported the pollen grain morphology of Origanum vulgare, Paeonia emodi, Psoralea corylifolia, and Rauwolfia serpentina for the first time. Similarly the crude drug study of Gymnema sylvestre (leaf), Origanum vulgare (aerial parts), Paeonia emodi (tubers), and Peganum harmala (seeds) was also carried out for the first time.

  18. Plant identification based on noisy web data: the amazing performance of deep learning (LifeCLEF 2017)

    OpenAIRE

    Goeau, Herve; Bonnet, Pierre; Joly, Alexis

    2017-01-01

    International audience; The 2017-th edition of the LifeCLEF plant identification challenge is an important milestone towards automated plant identification systems working at the scale of continental floras with 10.000 plant species living mainly in Europe and North America illustrated by a total of 1.1M images. Nowadays, such ambitious systems are enabled thanks to the conjunction of the dazzling recent progress in image classification with deep learning and several outstanding international...

  19. A pattern recognition approach based on DTW for automatic transient identification in nuclear power plants

    International Nuclear Information System (INIS)

    Galbally, Javier; Galbally, David

    2015-01-01

    Highlights: • Novel transient identification method for NPPs. • Low-complexity. • Low training data requirements. • High accuracy. • Fully reproducible protocol carried out on a real benchmark. - Abstract: Automatic identification of transients in nuclear power plants (NPPs) allows monitoring the fatigue damage accumulated by critical components during plant operation, and is therefore of great importance for ensuring that usage factors remain within the original design bases postulated by the plant designer. Although several schemes to address this important issue have been explored in the literature, there is still no definitive solution available. In the present work, a new method for automatic transient identification is proposed, based on the Dynamic Time Warping (DTW) algorithm, largely used in other related areas such as signature or speech recognition. The novel transient identification system is evaluated on real operational data following a rigorous pattern recognition protocol. Results show the high accuracy of the proposed approach, which is combined with other interesting features such as its low complexity and its very limited requirements of training data

  20. Hierarchical Learning of Tree Classifiers for Large-Scale Plant Species Identification.

    Science.gov (United States)

    Fan, Jianping; Zhou, Ning; Peng, Jinye; Gao, Ling

    2015-11-01

    In this paper, a hierarchical multi-task structural learning algorithm is developed to support large-scale plant species identification, where a visual tree is constructed for organizing large numbers of plant species in a coarse-to-fine fashion and determining the inter-related learning tasks automatically. For a given parent node on the visual tree, it contains a set of sibling coarse-grained categories of plant species or sibling fine-grained plant species, and a multi-task structural learning algorithm is developed to train their inter-related classifiers jointly for enhancing their discrimination power. The inter-level relationship constraint, e.g., a plant image must first be assigned to a parent node (high-level non-leaf node) correctly if it can further be assigned to the most relevant child node (low-level non-leaf node or leaf node) on the visual tree, is formally defined and leveraged to learn more discriminative tree classifiers over the visual tree. Our experimental results have demonstrated the effectiveness of our hierarchical multi-task structural learning algorithm on training more discriminative tree classifiers for large-scale plant species identification.

  1. Prospects and Problems for Identification of Poisonous Plants in China using DNA Barcodes.

    Science.gov (United States)

    Xie, Lei; Wang, Ying Wei; Guan, Shan Yue; Xie, Li Jing; Long, Xin; Sun, Cheng Ye

    2014-10-01

    Poisonous plants are a deadly threat to public health in China. The traditional clinical diagnosis of the toxic plants is inefficient, fallible, and dependent upon experts. In this study, we tested the performance of DNA barcodes for identification of the most threatening poisonous plants in China. Seventy-four accessions of 27 toxic plant species in 22 genera and 17 families were sampled and three DNA barcodes (matK, rbcL, and ITS) were amplified, sequenced and tested. Three methods, Blast, pairwise global alignment (PWG) distance, and Tree-Building were tested for discrimination power. The primer universality of all the three markers was high. Except in the case of ITS for Hemerocallis minor, the three barcodes were successfully generated from all the selected species. Among the three methods applied, Blast showed the lowest discrimination rate, whereas PWG Distance and Tree-Building methods were equally effective. The ITS barcode showed highest discrimination rates using the PWG Distance and Tree-Building methods. When the barcodes were combined, discrimination rates were increased for the Blast method. DNA barcoding technique provides us a fast tool for clinical identification of poisonous plants in China. We suggest matK, rbcL, ITS used in combination as DNA barcodes for authentication of poisonous plants. Copyright © 2014 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  2. Ethnobotanic study of medicinal plants in Urmia city: identification and traditional using of antiparasites plants

    Directory of Open Access Journals (Sweden)

    Mahmoud Bahmani

    2014-09-01

    Full Text Available Objective: To identify the native medicinal plants used in parasitic diseases treatment in Urmia. Methods: This study was conducted among 35 Urmia herbalists to identify medicinal plants used in parasitic diseases treatment. We used direct observation and interviews with collected herbarium specimens by native herbs commonly in the treatment of parasitic diseases. Questionnaires were included apothecary personal information and native plants list with information includes plant local name, plant parts used, method of their use and traditional therapies. Herbarium samples listed in the questionnaire collected from the area and were sent to agricultural research centers and Urmia University Faculty of Agriculture for genus and species determination. Results: Thirteen medicinal plants from six families for treatment of diabetes in Urmia were obtained from interviews. Most families have anti diabetic effect was included Asteraceae (36%. The most used was boiling (65%. Conclusions: In view of the findings of this study indicate that plants have the potential to be a parasitic infection so it is necessary ingredients of native plants be studied to demonstrate therapeutic effects and provide field work to evaluate the clinical effects of these herbs and ingredients they claim on parasitic diseases.

  3. An online ID identification system for liquefied-gas cylinder plant

    Science.gov (United States)

    He, Jin; Ding, Zhenwen; Han, Lei; Zhang, Hao

    2017-11-01

    An automatic ID identification system for gas cylinders' online production was developed based on the production conditions and requirements of the Technical Committee for Standardization of Gas Cylinders. A cylinder ID image acquisition system was designed to improve the image contrast of ID regions on gas cylinders against the background. Then the ID digits region was located by the CNN template matching algorithm. Following that, an adaptive threshold method based on the analysis of local average grey value and standard deviation was proposed to overcome defects of non-uniform background in the segmentation results. To improve the single digit identification accuracy, two BP neural networks were trained respectively for the identification of all digits and the easily confusable digits. If the single digit was classified as one of confusable digits by the former BP neural network, it was further tested by the later one, and the later result was taken as the final identification result of this single digit. At last, the majority voting was adopted to decide the final identification result for the 6-digit cylinder ID. The developed system was installed on a production line of a liquefied-petroleum-gas cylinder plant and worked in parallel with the existing weighing step on the line. Through the field test, the correct identification rate for single ID digit was 94.73%, and none of the tested 2000 cylinder ID was misclassified through the majority voting.

  4. Identification and reduction of piping-vibrations in plants

    Energy Technology Data Exchange (ETDEWEB)

    Kerkhof, K. [Stuttgart Univ. (Germany). MPA

    2012-07-01

    Safe operation, availability and lifetime assessment of piping systems are of utmost concern for plant operators. The use of tuned mass dampers is a rather new approach for reducing vibrations to avoid high cycle fatigue in a large chemical piping system. The investigated piping system is supported by a tall structure fixed at the base. As a result, the steel building stiffness decreases with height. Furthermore large piping-elbow forces act at the top of the building, which lead to large vibration amplitudes. Since both piping system and supporting structure exhibited these large vibration amplitudes, dampers or shock absorbers placed between them would prove ineffective. Therefore, special vibration absorbers were developed for such piping systems. The paper presents the design process, starting with an extensive system investigation up to the passive multi-axial vibration absorber design parameters. This includes: Laboratory tests with a mock-up pipe system, where the first design ideas for new passive vibration absorbers were investigated. Vibration measurements were carried out to investigate the current state of the vibration behaviour. The piping system was inspected; strain gauges were used to identify stress concentrations at welds and other notches due to ovalization. Finite element calculations were performed, first as a combined beam and shell model for the pipe without the support structure. A detailed model for the combined steel construction and pipe system was created. Model-updating was done to fit the calculated model to the experimental modal analysis data. Loading assumptions describing excitation forces from the mass flow were checked. Harmonic frequency analysis was performed. On the basis of these calculations design parameters for the passive vibration absorber were determined. Finally, a solution for the design of two passive vibration absorbers will be presented.

  5. Identification and reduction of piping-vibrations in plants

    International Nuclear Information System (INIS)

    Kerkhof, K.

    2012-01-01

    Safe operation, availability and lifetime assessment of piping systems are of utmost concern for plant operators. The use of tuned mass dampers is a rather new approach for reducing vibrations to avoid high cycle fatigue in a large chemical piping system. The investigated piping system is supported by a tall structure fixed at the base. As a result, the steel building stiffness decreases with height. Furthermore large piping-elbow forces act at the top of the building, which lead to large vibration amplitudes. Since both piping system and supporting structure exhibited these large vibration amplitudes, dampers or shock absorbers placed between them would prove ineffective. Therefore, special vibration absorbers were developed for such piping systems. The paper presents the design process, starting with an extensive system investigation up to the passive multi-axial vibration absorber design parameters. This includes: Laboratory tests with a mock-up pipe system, where the first design ideas for new passive vibration absorbers were investigated. Vibration measurements were carried out to investigate the current state of the vibration behaviour. The piping system was inspected; strain gauges were used to identify stress concentrations at welds and other notches due to ovalization. Finite element calculations were performed, first as a combined beam and shell model for the pipe without the support structure. A detailed model for the combined steel construction and pipe system was created. Model-updating was done to fit the calculated model to the experimental modal analysis data. Loading assumptions describing excitation forces from the mass flow were checked. Harmonic frequency analysis was performed. On the basis of these calculations design parameters for the passive vibration absorber were determined. Finally, a solution for the design of two passive vibration absorbers will be presented.

  6. Plutonium in a grassland ecosystem

    International Nuclear Information System (INIS)

    Little, C.A.

    1976-08-01

    A study was made of plutonium contamination of grassland at the Rocky Flats plant northwest of Denver, Colorado. Of interest were: the definition of major plutonium-containing ecosystem compartments; the relative amounts in those compartments; how those values related to studies done in other geographical areas; whether or not the predominant isotopes, 238 Pu and 239 Pu, behaved differently; and what mechanisms might have allowed for the observed patterns of contamination. Samples of soil, litter, vegetation, arthropods, and small mammals were collected for Pu analysis and mass determination from each of two macroplots. Small aliquots (5 g or less) were analyzed by a rapid liquid scintillation technique and by alpha spectrometry. Of the compartments sampled, greater than 99 percent of the total plutonium was contained in the soil and the concentrations were significantly inversely correlated with distance from the contamination source, depth of the sample, and particle size of the sieved soil samples. The soil data suggested that the distribution of contamination largely resulted from physical transport processes

  7. An efficient Neuro-Fuzzy approach to nuclear power plant transient identification

    Energy Technology Data Exchange (ETDEWEB)

    Gomes da Costa, Rafael [Instituto de Engenharia Nuclear - CNEN, Programa de Pos-Graduacao em Ciencia e Tecnologia Nucleares, Via Cinco, s/no, Cidade Universitaria, Rua Helio de Almeida, 75, Postal Box 68550, Zip Code 21941-906 Rio de Janeiro (Brazil); Abreu Mol, Antonio Carlos de, E-mail: mol@ien.gov.br [Instituto de Engenharia Nuclear - CNEN, Programa de Pos-Graduacao em Ciencia e Tecnologia Nucleares, Via Cinco, s/no, Cidade Universitaria, Rua Helio de Almeida, 75, Postal Box 68550, Zip Code 21941-906 Rio de Janeiro (Brazil); Instituto Nacional de C and T de Reatores Nucleares Inovadores (Brazil); Carvalho, Paulo Victor R. de, E-mail: paulov@ien.gov.br [Instituto de Engenharia Nuclear - CNEN, Programa de Pos-Graduacao em Ciencia e Tecnologia Nucleares, Via Cinco, s/no, Cidade Universitaria, Rua Helio de Almeida, 75, Postal Box 68550, Zip Code 21941-906 Rio de Janeiro (Brazil); Lapa, Celso Marcelo Franklin, E-mail: lapa@ien.gov.br [Instituto de Engenharia Nuclear - CNEN, Programa de Pos-Graduacao em Ciencia e Tecnologia Nucleares, Via Cinco, s/no, Cidade Universitaria, Rua Helio de Almeida, 75, Postal Box 68550, Zip Code 21941-906 Rio de Janeiro (Brazil); Instituto Nacional de C and T de Reatores Nucleares Inovadores (Brazil)

    2011-06-15

    Highlights: > We investigate a Neuro-Fuzzy modeling tool use for able transient identification. > The prelusive transient type identification is done by an artificial neural network. > After, the fuzzy-logic system analyzes the results emitting reliability degree of it. > The research support was made in a PWR simulator at the Brazilian Nuclear Engineering Institute. > The results show the potential to help operators' decisions in a nuclear power plant. - Abstract: Transient identification in nuclear power plants (NPP) is often a computational very hard task and may involve a great amount of human cognition. The early identification of unexpected departures from steady state behavior is an essential step for the operation, control and accident management in NPPs. The bases for the transient identification relay on the evidence that different system faults and anomalies lead to different pattern evolution in the involved process variables. During an abnormal event, the operator must monitor a great amount of information from the instruments that represents a specific type of event. Recently, several works have been developed for transient identification. These works frequently present a non reliable response, using the 'don't know' as the system output. In this work, we investigate the possibility of using a Neuro-Fuzzy modeling tool for efficient transient identification, aiming to helping the operator crew to take decisions relative to the procedure to be followed in situations of accidents/transients at NPPs. The proposed system uses artificial neural networks (ANN) as first level transient diagnostic. After the ANN has done the preliminary transient type identification, a fuzzy-logic system analyzes the results emitting reliability degree of it. A validation of this identification system was made at the three loops Pressurized Water Reactor (PWR) simulator of the Human-System Interface Laboratory (LABIHS) of the Nuclear Engineering Institute

  8. An efficient Neuro-Fuzzy approach to nuclear power plant transient identification

    International Nuclear Information System (INIS)

    Gomes da Costa, Rafael; Abreu Mol, Antonio Carlos de; Carvalho, Paulo Victor R. de; Lapa, Celso Marcelo Franklin

    2011-01-01

    Highlights: → We investigate a Neuro-Fuzzy modeling tool use for able transient identification. → The prelusive transient type identification is done by an artificial neural network. → After, the fuzzy-logic system analyzes the results emitting reliability degree of it. → The research support was made in a PWR simulator at the Brazilian Nuclear Engineering Institute. → The results show the potential to help operators' decisions in a nuclear power plant. - Abstract: Transient identification in nuclear power plants (NPP) is often a computational very hard task and may involve a great amount of human cognition. The early identification of unexpected departures from steady state behavior is an essential step for the operation, control and accident management in NPPs. The bases for the transient identification relay on the evidence that different system faults and anomalies lead to different pattern evolution in the involved process variables. During an abnormal event, the operator must monitor a great amount of information from the instruments that represents a specific type of event. Recently, several works have been developed for transient identification. These works frequently present a non reliable response, using the 'don't know' as the system output. In this work, we investigate the possibility of using a Neuro-Fuzzy modeling tool for efficient transient identification, aiming to helping the operator crew to take decisions relative to the procedure to be followed in situations of accidents/transients at NPPs. The proposed system uses artificial neural networks (ANN) as first level transient diagnostic. After the ANN has done the preliminary transient type identification, a fuzzy-logic system analyzes the results emitting reliability degree of it. A validation of this identification system was made at the three loops Pressurized Water Reactor (PWR) simulator of the Human-System Interface Laboratory (LABIHS) of the Nuclear Engineering Institute (IEN

  9. Variation in the carbon and oxygen isotope composition of plant biomass and its relationship to water-use efficiency at the leaf- and ecosystem-scales in a northern Great Plains grassland.

    Science.gov (United States)

    Flanagan, Lawrence B; Farquhar, Graham D

    2014-02-01

    Measurements of the carbon (δ(13) Cm ) and oxygen (δ(18) Om ) isotope composition of C3 plant tissue provide important insights into controls on water-use efficiency. We investigated the causes of seasonal and inter-annual variability in water-use efficiency in a grassland near Lethbridge, Canada using stable isotope (leaf-scale) and eddy covariance measurements (ecosystem-scale). The positive relationship between δ(13) Cm and δ(18) Om values for samples collected during 1998-2001 indicated that variation in stomatal conductance and water stress-induced changes in the degree of stomatal limitation of net photosynthesis were the major controls on variation in δ(13) Cm and biomass production during this time. By comparison, the lack of a significant relationship between δ(13) Cm and δ(18) Om values during 2002, 2003 and 2006 demonstrated that water stress was not a significant limitation on photosynthesis and biomass production in these years. Water-use efficiency was higher in 2000 than 1999, consistent with expectations because of greater stomatal limitation of photosynthesis and lower leaf ci /ca during the drier conditions of 2000. Calculated values of leaf-scale water-use efficiency were 2-3 times higher than ecosystem-scale water-use efficiency, a difference that was likely due to carbon lost in root respiration and water lost during soil evaporation that was not accounted for by the stable isotope measurements. © 2013 John Wiley & Sons Ltd.

  10. Crude protein changes on grassland along a degradation gradient ...

    African Journals Online (AJOL)

    Evapotranspiration was determined by quantifying the soil-water balance equation with the aid of runoff plots and soil-water content measurements. Crude protein ... The study shows that it is important to keep grassland in optimal condition to utilize limited soil water for sustainable plant and therefore animal production.

  11. Relationship between soil chemical factors and grassland diversity

    NARCIS (Netherlands)

    Janssens, F; Peeters, A; Tallowin, JRB; Bakker, JP; Bekker, RM; Fillat, F; Oomes, MJM

    Many studies carried out during these last few years have focused on the factors influencing plant diversity in species-rich grasslands. This is due to the fact that these ecosystems, among the most diversified in temperate climates, are extremely threatened; in some areas, they have almost

  12. Grassland birds wintering at U.S. Navy facilities in southern Texas

    Science.gov (United States)

    Woodin, Marc C.; Skoruppa, Mary Kay; Bryan, Pearce D.; Ruddy, Amanda J.; Hickman, Graham C.

    2010-01-01

    Grassland birds have undergone widespread decline throughout North America during the past several decades. Causes of this decline include habitat loss and fragmentation because of conversion of grasslands to cropland, afforestation in the East, brush and shrub invasion in the Southwest and western United States, and planting of exotic grass species to enhance forage production. A large number of exotic plant species, including grasses, have been introduced in North America, but most research on the effects of these invasions on birds has been limited to breeding birds, primarily those in northern latitudes. Research on the effects of exotic grasses on birds in winter has been extremely limited.This is the first study in southern Texas to examine and compare winter bird responses to native and exotic grasslands. This study was conducted during a period of six years (2003–2009) on United States Navy facilities in southern Texas including Naval Air Station–Corpus Christi, Naval Air Station–Kingsville, Naval Auxiliary Landing Field Waldron, Naval Auxiliary Landing Field Orange Grove, and Escondido Ranch, all of which contained examples of native grasslands, exotic grasslands, or both. Data from native and exotic grasslands were collected and compared for bird abundance and diversity; ground cover, vegetation density, and floristic diversity; bird and vegetation relationships; diversity of insects and arachnids; and seed abundance and diversity. Effects of management treatments in exotic grasslands were evaluated by comparing numbers and diversity of birds and small mammals in mowed, burned, and control areas.To determine bird abundance and bird species richness, birds were surveyed monthly (December–February) during the winters of 2003–2008 in transects (100 meter × 20 meter) located in native and exotic grasslands distributed at all five U.S. Navy facilities. To compare vegetation in native and exotic grasslands, vegetation characteristics were measured

  13. Various approaches in EPR identification of gamma-irradiated plant foodstuffs: A review.

    Science.gov (United States)

    Aleksieva, Katerina I; Yordanov, Nicola D

    2018-03-01

    Irradiation of food in the world is becoming a preferred method for their sterilization and extending their shelf life. For the purpose of trade with regard to the rights of consumers is necessary marking of irradiated foodstuffs, and the use of appropriate methods for unambiguous identification of radiation treatment. One-third of the current standards of the European Union to identify irradiated foods use the method of the Electron Paramagnetic Resonance (EPR) spectroscopy. On the other hand the current standards for irradiated foods of plant origin have some weaknesses that led to the development of new methodologies for the identification of irradiated food. New approaches for EPR identification of radiation treatment of herbs and spices when the specific signal is absent or disappeared after irradiation are discussed. Direct EPR measurements of dried fruits and vegetables and different pretreatments for fresh samples are reviewed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Vital area identification software VIP for the physical protection of nuclear power plants

    International Nuclear Information System (INIS)

    Jung, Woo Sik; Park, Chang Kue; Yang, Joon Eon

    2004-01-01

    There are two major factors to be considered for the physical protection of nuclear power plants. They are a design basis threat (DBT) and the vital area identification (VAI). The DBT has been considered as 'the maximum credible threat.' The vital area is defined as 'an area inside a protected area containing equipment, systems or devices, or nuclear materials, the sabotage of which could directly or indirectly lead to unacceptable radiological consequences.' For the VAI of nuclear power plants, a software VIP (Vital area Identification Package based on PSA method) is being developed. The VIP is based on the current probabilistic safety assessment (PSA) techniques. The PSA method, including internal as well as external events, is known as the most complete and consistent method for identifying various accident sequences that might result in a core melt and radioactive material release to the environment. Thus, the VIP employs a fault tree analysis method in the PSA and utilizes the PSA results

  15. Identification of seismically risk-sensitive systems and components in nuclear power plants: feasibility study

    International Nuclear Information System (INIS)

    Azarm, M.; Boccio, J.; Farahzad, P.

    1983-06-01

    An approach for the identification of risk-sensitive components in a nuclear power plant during and after a seismic event is described. Application of the methodology to two hypothetical power plants - a Boiling Water Reactor and a Pressurized Water Reactor - are presented and the results are given in tabular and graphical form. Conclusions drawn and lessons learned through the course of this study, based on the relative importance of various accident scenarios and sensitivity analyses, are discussed. In addition, the areas that may need further investigation are identified

  16. A comparative analysis of machine learning approaches for plant disease identification

    Directory of Open Access Journals (Sweden)

    Hidayat ur Rahman

    2017-08-01

    Full Text Available Background: The problems to leaf in plants are very severe and they usually shorten the lifespan of plants. Leaf diseases are mainly caused due to three types of attacks including viral, bacterial or fungal. Diseased leaves reduce the crop production and affect the agricultural economy. Since agriculture plays a vital role in the economy, thus effective mechanism is required to detect the problem in early stages. Methods: Traditional approaches used for the identification of diseased plants are based on field visits which is time consuming and tedious. In this paper a comparative analysis of machine learning approaches has been presented for the identification of healthy and non-healthy plant leaves. For experimental purpose three different types of plant leaves have been selected namely, cabbage, citrus and sorghum. In order to classify healthy and non-healthy plant leaves color based features such as pixels, statistical features such as mean, standard deviation, min, max and descriptors such as Histogram of Oriented Gradients (HOG have been used. Results: 382 images of cabbage, 539 images of citrus and 262 images of sorghum were used as the primary dataset. The 40% data was utilized for testing and 60% were used for training which consisted of both healthy and damaged leaves. The results showed that random forest classifier is the best machine method for classification of healthy and diseased plant leaves. Conclusion: From the extensive experimentation it is concluded that features such as color information, statistical distribution and histogram of gradients provides sufficient clue for the classification of healthy and non-healthy plants.

  17. Review of scientific Research results in identification of plant raw materials in food products

    OpenAIRE

    GOLUBTSOVA YU. V.

    2016-01-01

    Currently, the science-based capabilities have been generated to develop and test various identification methods of food products and reveal adulteration using advanced technique and processes. This article reviews researches and developments to identify the plant raw materials in food products based on morphological, anatomic, physical and chemical test methods and the latest DNA-technologies. Review of physical, chemical, anatomic and morphological test methods to identify raw materials bot...

  18. Plutonium Finishing Plant (PFP) Standards/Requirements Identification Document (S/RID)

    Energy Technology Data Exchange (ETDEWEB)

    Maddox, B.S.

    1996-01-01

    This Standards/Requirements Identification Document (S/RID) sets forth the Environmental Safety and Health (ESH) standards/requirements for the Plutonium Finishing Plant (PFP). This S/RID is applicable to the appropriate life cycle phases of design, construction, operation, and preparation for decommissioning. These standards/requirements are adequate to ensure the protection of the health and safety of workers, the public, and the environment.

  19. Plutonium Finishing Plant (PFP) Standards/Requirements Identification Document (S/RID)

    International Nuclear Information System (INIS)

    Maddox, B.S.

    1996-01-01

    This Standards/Requirements Identification Document (S/RID) sets forth the Environmental Safety and Health (ESH) standards/requirements for the Plutonium Finishing Plant (PFP). This S/RID is applicable to the appropriate life cycle phases of design, construction, operation, and preparation for decommissioning. These standards/requirements are adequate to ensure the protection of the health and safety of workers, the public, and the environment

  20. Effects of elevated CO₂, warming and precipitation change on plant growth, photosynthesis and peroxidation in dominant species from North China grassland.

    Science.gov (United States)

    Xu, Zhenzhu; Shimizu, Hideyuki; Ito, Shoko; Yagasaki, Yasumi; Zou, Chunjing; Zhou, Guangsheng; Zheng, Yuanrun

    2014-02-01

    Warming, watering and elevated atmospheric CO₂-concentration effects have been extensively studied separately; however, their combined impact on plants is not well understood. In the current research, we examined plant growth and physiological responses of three dominant species from the Eurasian Steppe with different functional traits to a combination of elevated CO₂, high temperature, and four simulated precipitation patterns. Elevated CO₂ stimulated plant growth by 10.8-41.7 % for a C₃ leguminous shrub, Caragana microphylla, and by 33.2-52.3 % for a C₃ grass, Stipa grandis, across all temperature and watering treatments. Elevated CO₂, however, did not affect plant biomass of a C₄ grass, Cleistogenes squarrosa, under normal or increased precipitation, whereas a 20.0-69.7 % stimulation of growth occurred with elevated CO₂ under drought conditions. Plant growth was enhanced in the C₃ shrub and the C₄ grass by warming under normal precipitation, but declined drastically with severe drought. The effects of elevated CO₂ on leaf traits, biomass allocation and photosynthetic potential were remarkably species-dependent. Suppression of photosynthetic activity, and enhancement of cell peroxidation by a combination of warming and severe drought, were partly alleviated by elevated CO₂. The relationships between plant functional traits and physiological activities and their responses to climate change were discussed. The present results suggested that the response to CO₂ enrichment may strongly depend on the response of specific species under varying patterns of precipitation, with or without warming, highlighting that individual species and multifactor dependencies must be considered in a projection of terrestrial ecosystem response to climatic change.

  1. Pollination biology in a tropical high-altitude grassland in Brazil: Interactions at the community level

    OpenAIRE

    Freitas, L; Sazima, M

    2006-01-01

    Surveys of local assemblages of plants and their pollinators are among the most useful ways to evaluate specialization in pollination and to discuss the patterns of plant-pollinator interactions among ecosystems. The high-altitude grasslands from southeastern Brazil constitute diminutive island-like formations surrounded by montane rainforests. We registered the floral traits of 124 species from the Serra da Bricaina grasslands (about 60% of the animal-pollinated species of this flora), and d...

  2. Wetland Plant Guide for Assessing Habitat Impacts of Real-Time Salinity Management

    OpenAIRE

    Quinn, Nigel W.T.; Feldmann, Sara A.

    2004-01-01

    This wetland plant guide was developed to aid moist soil plant identification and to assist in the mapping of waterfowl and shorebird habitat in the Grassland Water District and surrounding wetland areas. The motivation for this habitat mapping project was a concern that real-time salinity management of wetland drainage might have long-term consequences for wildfowl habitat health -- changes in wetland drawdown schedules might, over the long term, lead to increased soil salinity and othe...

  3. Genetic identification of female Cannabis sativa plants at early developmental stage.

    Science.gov (United States)

    Techen, Natascha; Chandra, Suman; Lata, Hemant; Elsohly, Mahmoud A; Khan, Ikhlas A

    2010-11-01

    Sequence-characterized amplified region (SCAR) markers were used to identify female plants at an early developmental stage in four different varieties of Cannabis sativa. Using the cetyl trimethylammonium bromide (CTAB) method, DNA was isolated from two-week-old plants of three drug-type varieties (Terbag W1, Terbag K2, and Terbag MX) and one fiber-type variety (Terbag Fedora A7) of C. sativa grown under controlled environmental conditions through seeds. Attempts to use MADC2 (male-associated DNA from Cannabis sativa) primers as a marker to identify the sex of Cannabis sativa plants were successful. Amplification of genomic DNA using MADC2-F and MADC2-R primers produced two distinct fragments, one with a size of approximately 450 bp for female plants and one for male plants with a size of approximately 300 bp. After harvesting the tissues for DNA extraction, plants were subjected to a flowering photoperiod (i.e., 12-h light cycle), and the appearance of flowers was compared with the DNA analysis. The results of the molecular analysis were found to be concordant with the appearance of male or female flowers. The results of this study represent a quick and reliable technique for the identification of sex in Cannabis plants using SCAR markers at a very early developmental stage. © Georg Thieme Verlag KG Stuttgart · New York.

  4. Code for plant identification (KKS) key in PC version. KKS-Schluessel-Programm in PC-Version

    Energy Technology Data Exchange (ETDEWEB)

    Pannenbaecker, K. (GABO Gesellschaft fuer Ablauforganisation und Informationsverarbeitung mbH, Erlangen (Germany) GABO Gesellschaft fuer Ablauforganisation und Informationsverarbeitung mbH, Muenchen (Germany))

    1991-11-01

    The plant identification system (KKS) as a common development of german plant operators, erection firms and also power plant oriented organisations have decisively influenced the technical-organizing activities of planning and erections as operations and maintenance of all kind of power plants. Fundamentals are three key parts, operation, armatures and function keys. Their management and application is executed by a plantidentification-key code in a PC version, which is briefly described in this report. (orig.).

  5. The application of PSA techniques to the vital area identification of nuclear power plants

    International Nuclear Information System (INIS)

    Ha, Jae Joo; Jung, Woo Sik; Park, Chang Kue

    2005-01-01

    This paper presents a Vital Area Identification (VAI) method based on the current Fault Tree Analysis (FTA) and Probabilistic Safety Assessment (PSA) techniques for the physical protection of nuclear power plants. A structured framework of a Top Event Prevention set Analysis (TEPA) application to the VAI of nuclear power plants is also delineated. One of the important processes for physical protection in a nuclear power plant is VIA that is a process for identifying areas containing nuclear materials, Structures, Systems or Components (SSCs) to be protected from sabotage, which could directly or indirectly lead to core damage and unacceptable radiological consequences. A software VIP (Vital area Identification Package based on the PSA method) is being developed by KAERI for the VAI of nuclear power plants. Furthermore, the KAERI fault tree solver FTREX (Fault Tree Reliability Evaluation eXpert) is specialized for the VIP to generate the candidates of the vital areas. FTREX can generate numerous MCSs for a huge fault tree with the lowest truncation limit and all possible prevention sets

  6. Plant Identification Based on Leaf Midrib Cross-Section Images Using Fractal Descriptors.

    Directory of Open Access Journals (Sweden)

    Núbia Rosa da Silva

    Full Text Available The correct identification of plants is a common necessity not only to researchers but also to the lay public. Recently, computational methods have been employed to facilitate this task, however, there are few studies front of the wide diversity of plants occurring in the world. This study proposes to analyse images obtained from cross-sections of leaf midrib using fractal descriptors. These descriptors are obtained from the fractal dimension of the object computed at a range of scales. In this way, they provide rich information regarding the spatial distribution of the analysed structure and, as a consequence, they measure the multiscale morphology of the object of interest. In Biology, such morphology is of great importance because it is related to evolutionary aspects and is successfully employed to characterize and discriminate among different biological structures. Here, the fractal descriptors are used to identify the species of plants based on the image of their leaves. A large number of samples are examined, being 606 leaf samples of 50 species from Brazilian flora. The results are compared to other imaging methods in the literature and demonstrate that fractal descriptors are precise and reliable in the taxonomic process of plant species identification.

  7. Towards the identification of plant and animal binders on Australian stone knives.

    Science.gov (United States)

    Blee, Alisa J; Walshe, Keryn; Pring, Allan; Quinton, Jamie S; Lenehan, Claire E

    2010-07-15

    There is limited information regarding the nature of plant and animal residues used as adhesives, fixatives and pigments found on Australian Aboriginal artefacts. This paper reports the use of FTIR in combination with the chemometric tools principal component analysis (PCA) and hierarchical clustering (HC) for the analysis and identification of Australian plant and animal fixatives on Australian stone artefacts. Ten different plant and animal residues were able to be discriminated from each other at a species level by combining FTIR spectroscopy with the chemometric data analysis methods, principal component analysis (PCA) and hierarchical clustering (HC). Application of this method to residues from three broken stone knives from the collections of the South Australian Museum indicated that two of the handles of knives were likely to have contained beeswax as the fixative whilst Spinifex resin was the probable binder on the third. Copyright 2010 Elsevier B.V. All rights reserved.

  8. Modelling and developing a decision-making process of hazard zone identification in ship power plants

    International Nuclear Information System (INIS)

    Podsiadlo, Antoni; Tarelko, Wieslaw

    2006-01-01

    The most dangerous places in ships are their power plants. Particularly, they are very unsafe for operators carried out various necessary operation and maintenance activities. For this reason, ship machinery should be designed to ensure the maximum safety for its operators. It is a very difficult task. Therefore, it could not be solved by means of conventional design methods, which are used for design of uncomplicated technical equipment. One of the possible ways of solving this problem is to provide appropriate tools, which allow us to take the operator's safety into account during a design process, especially at its early stages. A computer-aided system supporting design of safe ship power plants could be such a tool. This paper deals with developing process of a prototype of the computer-aided system for hazard zone identification in ship power plants

  9. Modelling and developing a decision-making process of hazard zone identification in ship power plants

    Energy Technology Data Exchange (ETDEWEB)

    Podsiadlo, Antoni [Department of Engineering Sciences, Gdynia Maritime University, ul. Morska 83, 81-225 Gdynia (Poland)]. E-mail: topo@am.gdynia.pl; Tarelko, Wieslaw [Department of Engineering Sciences, Gdynia Maritime University, ul. Morska 83, 81-225 Gdynia (Poland)]. E-mail: tar@am.gdynia.pl

    2006-04-15

    The most dangerous places in ships are their power plants. Particularly, they are very unsafe for operators carried out various necessary operation and maintenance activities. For this reason, ship machinery should be designed to ensure the maximum safety for its operators. It is a very difficult task. Therefore, it could not be solved by means of conventional design methods, which are used for design of uncomplicated technical equipment. One of the possible ways of solving this problem is to provide appropriate tools, which allow us to take the operator's safety into account during a design process, especially at its early stages. A computer-aided system supporting design of safe ship power plants could be such a tool. This paper deals with developing process of a prototype of the computer-aided system for hazard zone identification in ship power plants.

  10. Host Plants Identification for Adult Agrotis ipsilon, a Long-Distance Migratory Insect

    Directory of Open Access Journals (Sweden)

    Yongqiang Liu

    2016-06-01

    Full Text Available In this study, we determined the host relationship of Agrotis ipsilon moths by identifying pollen species adhering them during their long-distance migration. Pollen carried by A. ipsilon moths was collected from 2012 to 2014 on a small island in the center of the Bohai Strait, which is a seasonal migration pathway of this pest species. Genomic DNA of single pollen grains was amplified by using whole genome amplification technology, and a portion of the chloroplast rbcL sequence was then amplified from this material. Pollen species were identified by a combination of DNA barcoding and pollen morphology. We found 28 species of pollen from 18 families on the tested moths, mainly from Angiosperm, Dicotyledoneae. From this, we were able to determine that these moths visit woody plants more than herbaceous plants that they carry more pollen in the early and late stages of the migration season, and that the amounts of pollen transportation were related to moth sex, moth body part, and plant species. In general, 31% of female and 26% of male moths were found to be carrying pollen. Amounts of pollen on the proboscis was higher for female than male moths, while the reverse was true for pollen loads on the antennae. This work provides a new approach to study the interactions between noctuid moth and their host plants. Identification of plant hosts for adult moths furthers understanding of the coevolution processes between moths and their host plants.

  11. Identification of species adulteration in traded medicinal plant raw drugs using DNA barcoding.

    Science.gov (United States)

    Nithaniyal, Stalin; Vassou, Sophie Lorraine; Poovitha, Sundar; Raju, Balaji; Parani, Madasamy

    2017-02-01

    Plants are the major source of therapeutic ingredients in complementary and alternative medicine (CAM). However, species adulteration in traded medicinal plant raw drugs threatens the reliability and safety of CAM. Since morphological features of medicinal plants are often not intact in the raw drugs, DNA barcoding was employed for species identification. Adulteration in 112 traded raw drugs was tested after creating a reference DNA barcode library consisting of 1452 rbcL and matK barcodes from 521 medicinal plant species. Species resolution of this library was 74.4%, 90.2%, and 93.0% for rbcL, matK, and rbcL + matK, respectively. DNA barcoding revealed adulteration in about 20% of the raw drugs, and at least 6% of them were derived from plants with completely different medicinal or toxic properties. Raw drugs in the form of dried roots, powders, and whole plants were found to be more prone to adulteration than rhizomes, fruits, and seeds. Morphological resemblance, co-occurrence, mislabeling, confusing vernacular names, and unauthorized or fraudulent substitutions might have contributed to species adulteration in the raw drugs. Therefore, this library can be routinely used to authenticate traded raw drugs for the benefit of all stakeholders: traders, consumers, and regulatory agencies.

  12. Plant identification credibility in ethnobotany: a closer look at Polish ethnographic studies

    Directory of Open Access Journals (Sweden)

    Łuczaj Łukasz J

    2010-12-01

    Full Text Available Abstract Background This paper is an attempt to estimate the percentage of erroneously identified taxa in ethnographic studies concerning the use of plants and to propose a code for recording credibility of identification in historical ethnobotany publications. Methods A sample of Polish-language ethnobotanical literature (45 published sources from 1874-2005 and four collections of voucher specimens (from 1894-1975 were analyzed. Errors were detected in the publications by comparing the data with existing knowledge on the distribution of plant names and species ranges. The voucher specimens were re-examined. A one-letter code was invented for quick identification of the credibility of data published in lists of species compiled from historical or ethnographic sources, according to the source of identification: voucher specimen, Latin binominal, botanical expert, obvious widespread name, folk name, mode of use, range, physical description or photograph. To test the use of the code an up-to-date list of wild food plants used in Poland was made. Results A significant difference between the ratio of mistakes in the voucher specimen collections and the ratio of detectable mistakes in the studies without herbarium documentation was found. At least 2.3% of taxa in the publications were identified erroneously (mean rate was 6.2% per publication, and in half of these mistakes even the genus was not correct. As many as 10.0% of voucher specimens (on average 9.2% per collection were originally erroneously identified, but three quarters of the identification mistakes remained within-genus. The species of the genera Thymus, Rumex and Rubus were most often confused within the genus. Not all of the invented credibility codes were used in the list of wild food plants, but they may be useful for other researchers. The most often used codes were the ones signifying identification by: voucher specimen, botanical expert and by a common name used throughout the

  13. Plant identification credibility in ethnobotany: a closer look at Polish ethnographic studies.

    Science.gov (United States)

    Łuczaj, Łukasz J

    2010-12-17

    This paper is an attempt to estimate the percentage of erroneously identified taxa in ethnographic studies concerning the use of plants and to propose a code for recording credibility of identification in historical ethnobotany publications. A sample of Polish-language ethnobotanical literature (45 published sources from 1874-2005) and four collections of voucher specimens (from 1894-1975) were analyzed. Errors were detected in the publications by comparing the data with existing knowledge on the distribution of plant names and species ranges. The voucher specimens were re-examined.A one-letter code was invented for quick identification of the credibility of data published in lists of species compiled from historical or ethnographic sources, according to the source of identification: voucher specimen, Latin binominal, botanical expert, obvious widespread name, folk name, mode of use, range, physical description or photograph. To test the use of the code an up-to-date list of wild food plants used in Poland was made. A significant difference between the ratio of mistakes in the voucher specimen collections and the ratio of detectable mistakes in the studies without herbarium documentation was found. At least 2.3% of taxa in the publications were identified erroneously (mean rate was 6.2% per publication), and in half of these mistakes even the genus was not correct. As many as 10.0% of voucher specimens (on average 9.2% per collection) were originally erroneously identified, but three quarters of the identification mistakes remained within-genus.The species of the genera Thymus, Rumex and Rubus were most often confused within the genus.Not all of the invented credibility codes were used in the list of wild food plants, but they may be useful for other researchers. The most often used codes were the ones signifying identification by: voucher specimen, botanical expert and by a common name used throughout the country. The results of this study support the rigorous use

  14. Plant state identification using fuzzy logic in the framework of computerized accident management support (CAMS)

    International Nuclear Information System (INIS)

    Van Dyck, Claude

    1997-05-01

    CAMS (computerized accident management support) is a system that will provide assistance in case of accident in a nuclear power plant. In order to support the user in evaluating the plant state, it contains a state identification module. The state identification module provides high-level, qualitative information about the status of critical safety functions, about the availability of safety systems and about the occurrence of initiating events. This information is sent to the man-machine interface and to other CAMS modules. The state identification module is developed using a specific tool: GPS (Goal Processing System) which is based on the Goal Tree - Success Tree formalism. GPS is a tool designed to manage ''process related'' knowledge and aimed at process supervision via real-time acquisition of process variables. Fuzzy logic has been introduced in GPS in order to have smoother transitions between different states of critical safety functions and systems changes and to have a truth value associated to each piece of information provided to the user. The whole system has been tested, integrated with the rest of CAMS, on several accident scenarios. The test results are satisfactory. A brief comparison is made between the present work and previous related work at the HRP. (author)

  15. Plutonium in a grassland ecosystem

    International Nuclear Information System (INIS)

    Little, C.A.

    1976-01-01

    This study was concerned with plutonium contamination of grassland at the U.S. Energy Research and Development Administration Rocky Flats plant northwest of Denver, Colorado. Of interest were: the definition of major plutonium-containing ecosystem compartments; the relative amounts in those compartments; how those values related to studies done in other geogrphical areas; whether or not the predominant isotopes, 238 Pu and 239 Pu, behaved differently; and what mechanisms might have allowed for the observed patterns of contamination. Samples of soil, litter, vegetation, arthropods, and small mammals were collected for plutonium analysis and mass determination from each of two macroplots. Small aliquots (5 g or less) were analyzed by a rapid liquid scintillation technique and by alpha spectrometry. Of the compartments sampled, greater than 99% of the total plutonium was contained in the soil. The concentrations of plutonium in soil were significantly inversely correlated with distance from the contamination source, depth of the sample, and particle size of the sieved soil samples. The soil data suggested that the distribution of contamination largely resulted from physical transport processes. A mechanism of agglomerated submicron plutonium oxide particles and larger (1-500 μm) host soil particles was proposed. Concentrations of Pu in litter and vegetation were inversely correlated to distance from the source and directly correlated to soil concentrations at the same location. Comparatively high concentration ratios of vegetation to soil suggested wind resuspension of contamination as an important transport mechanism. Arthropod and small mammal samples were highly skewed, kurtotic, and quite variable, having coefficients of variation (standard deviation/mean) as high as 600%. Bone Pu concentrations were lower than other tissues. Hide, GI, and lung were generally not higher in Pu than kidney, liver and muscle

  16. Restoration of species-rich grasslands on ex-arable land: Seed addition outweighs soil fertility reduction

    NARCIS (Netherlands)

    Kardol, P.; Van der Wal, A.; Bezemer, T.M.; De Boer, W.; Duyts, H.; Holtkamp, R.; Van der Putten, W.H.

    2008-01-01

    A common practice in biodiversity conservation is restoration of former species-rich grassland on ex-arable land. Major constraints for grassland restoration are high soil fertility and limited dispersal ability of plant species to target sites. Usually, studies focus on soil fertility or on methods

  17. A review for identification of initiating events in event tree development process on nuclear power plants

    International Nuclear Information System (INIS)

    Riyadi, Eko H.

    2014-01-01

    Initiating event is defined as any event either internal or external to the nuclear power plants (NPPs) that perturbs the steady state operation of the plant, if operating, thereby initiating an abnormal event such as transient or loss of coolant accident (LOCA) within the NPPs. These initiating events trigger sequences of events that challenge plant control and safety systems whose failure could potentially lead to core damage or large early release. Selection for initiating events consists of two steps i.e. first step, definition of possible events, such as by evaluating a comprehensive engineering, and by constructing a top level logic model. Then the second step, grouping of identified initiating event's by the safety function to be performed or combinations of systems responses. Therefore, the purpose of this paper is to discuss initiating events identification in event tree development process and to reviews other probabilistic safety assessments (PSA). The identification of initiating events also involves the past operating experience, review of other PSA, failure mode and effect analysis (FMEA), feedback from system modeling, and master logic diagram (special type of fault tree). By using the method of study for the condition of the traditional US PSA categorization in detail, could be obtained the important initiating events that are categorized into LOCA, transients and external events

  18. A review for identification of initiating events in event tree development process on nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Riyadi, Eko H., E-mail: e.riyadi@bapeten.go.id [Center for Regulatory Assessment of Nuclear Installation and Materials, Nuclear Energy Regulatory Agency (BAPETEN), Jl. Gajah Mada 8 Jakarta 10120 (Indonesia)

    2014-09-30

    Initiating event is defined as any event either internal or external to the nuclear power plants (NPPs) that perturbs the steady state operation of the plant, if operating, thereby initiating an abnormal event such as transient or loss of coolant accident (LOCA) within the NPPs. These initiating events trigger sequences of events that challenge plant control and safety systems whose failure could potentially lead to core damage or large early release. Selection for initiating events consists of two steps i.e. first step, definition of possible events, such as by evaluating a comprehensive engineering, and by constructing a top level logic model. Then the second step, grouping of identified initiating event's by the safety function to be performed or combinations of systems responses. Therefore, the purpose of this paper is to discuss initiating events identification in event tree development process and to reviews other probabilistic safety assessments (PSA). The identification of initiating events also involves the past operating experience, review of other PSA, failure mode and effect analysis (FMEA), feedback from system modeling, and master logic diagram (special type of fault tree). By using the method of study for the condition of the traditional US PSA categorization in detail, could be obtained the important initiating events that are categorized into LOCA, transients and external events.

  19. Protecting Mongolia's grassland steppes | CRDI - Centre de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... windy grassland region is severely damaged, desertification can quickly set in. ... to marketing to the sound use of (grassland) resources," explains Ykhanbai, who ... is going to require improvement in the skills of researchers, adds Ykhanbai.

  20. Plant-conservative agriculture of acid and degraded Raña-grassland enhances diversity of the common soil mites (Oribatida)

    Energy Technology Data Exchange (ETDEWEB)

    Jorrín, J.; González-Fernández, P.

    2016-11-01

    The seminatural prairie of the Raña of Cañamero (Spain) is a degraded and unproductive agrosystem with acid and stony soils, and low coverage of xerophytic grasses. In a project about secondary reconversion of the raña-prairie to a more productive cropland, an experimental field (EF) was established to assess the effect on plot-productivity of the interaction between correction of soil pH (liming) with three cropping systems: a no-tilled and annually fertilized and improved prairies, and a conventionally-tilled forage crop. The EF model of management was designed as plant-conservative, because no herbicide was applied after seeding to preserve the post-emergence of wild herbs and the natural grass diversity of the prairie. Between 2008 and 2012, we analysed the effect of managing factors (initial conventional-tillage, fertilization, liming and cropping) and agricultural predictors (pH, C:N ratio, soil bulk density and herbaceous biomass) on the alpha(α)-diversity of one of the major group of soil animals, the oribatids. In relation to the raña-prairie, all EF-plots improved their soil bulk density (ρs) and herbaceous biomass (t/ha), and enhanced desirable α-diversity values (richness, abundance and community equity). We conclude that the plant-conservative model: i) do not affect statistically the species richness of the prairie; ii) the desirable α-diversity responses are negatively correlated with soil bulk density and positively with herbaceous biomass, and iii) the low input or minimum intervention model, of an initial and conventional till and annual fertilisation, is the threshold and optimal model of agricultural management to improving oribatids diversity of the raña-soil. (Author)

  1. Filtering technique for detection and identification of measurement failures in nuclear power plants

    International Nuclear Information System (INIS)

    Racz, A.

    1989-11-01

    The basic requirement of the safe operation of nuclear power plants (NPP) is to have reliable information on all quantities that can be measured, monitored or controlled during the operation. Kalman filtering techniques have been applied for prompt detection and identification of failures in the measurement systems used in NPPs. Mathematical basis of Kalman filtering and various models applied to failure detection are overviewed. The applicability of some models are evaluated by real results of NPP measurements. A sample system for an NPP is suggested, based on several numerical tests. (R.P.) 23 refs.; 40 figs.; 2 tabs

  2. Multivariate algorithms for initiating event detection and identification in nuclear power plants

    International Nuclear Information System (INIS)

    Wu, Shun-Chi; Chen, Kuang-You; Lin, Ting-Han; Chou, Hwai-Pwu

    2018-01-01

    Highlights: •Multivariate algorithms for NPP initiating event detection and identification. •Recordings from multiple sensors are simultaneously considered for detection. •Both spatial and temporal information is used for event identification. •Untrained event isolation avoids falsely relating an untrained event. •Efficacy of the algorithms is verified with data from the Maanshan NPP simulator. -- Abstract: To prevent escalation of an initiating event into a severe accident, promptly detecting its occurrence and precisely identifying its type are essential. In this study, several multivariate algorithms for initiating event detection and identification are proposed to help maintain safe operations of nuclear power plants (NPPs). By monitoring changes in the NPP sensing variables, an event is detected when the preset thresholds are exceeded. Unlike existing approaches, recordings from sensors of the same type are simultaneously considered for detection, and no subjective reasoning is involved in setting these thresholds. To facilitate efficient event identification, a spatiotemporal feature extractor is proposed. The extracted features consist of the temporal traits used by existing techniques and the spatial signature of an event. Through an F-score-based feature ranking, only those that are most discriminant in classifying the events under consideration will be retained for identification. Moreover, an untrained event isolation scheme is introduced to avoid relating an untrained event to those in the event dataset so that improper recovery actions can be prevented. Results from experiments containing data of 12 event classes and a total of 125 events generated using a Taiwan’s Maanshan NPP simulator are provided to illustrate the efficacy of the proposed algorithms.

  3. Appreciation of grassland functions by European stakeholders

    NARCIS (Netherlands)

    Pol, van den A.; Golinski, P.; Hennessy, D.; Huyghe, C.; Parente, G.; Peyraud, J.L.

    2014-01-01

    In order to promote sustainable and competitive ruminant production systems, the European Multisward project was aimed at improving farmer trust in grassland and grassland mixtures. A questionnaire on grassland functions was submitted in eight languages, in order to better understand the importance

  4. Effects of elevated ozone on leaf {delta}{sup 13}C and leaf conductance of plant species grown in semi-natural grassland with or without irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Jaeggi, M. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Air Pollution/Climate Group, CH-8046 Zurich (Switzerland)]. E-mail: maya.jaeggi@psi.ch; Saurer, M. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Volk, M. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Air Pollution/Climate Group, CH-8046 Zurich (Switzerland); Fuhrer, J. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Air Pollution/Climate Group, CH-8046 Zurich (Switzerland)

    2005-03-01

    Stable carbon isotope ratios ({delta}{sup 13}C) and leaf conductance (g{sub s}) were measured (2002, 2003) in Holcus lanatus L., Plantago lanceolata L. Ranunculus friesianus (Jord.), and Trifolium pratense L. at two levels of ozone (O{sub 3}) with or without irrigation. In non-irrigated control plots, R. friesianus showed the least negative {delta}{sup 13}C, and the smallest response to the treatments. Irrigation caused more negative {delta}{sup 13}C, especially in H. lanatus. Irrespective of irrigation, O{sub 3} increased {delta}{sup 13}C in relationship to a decrease in g{sub s} in P. lanceolata and T. pratense. The strongest effect of O{sub 3} on {delta}{sup 13}C occurred in the absence of irrigation, suggesting that under field conditions lack of moisture in the top soil does not always lead to protection from O{sub 3} uptake. It is concluded that in species such as T. pratense plants can maintain stomatal O{sub 3} uptake during dry periods when roots can reach deeper soil layers where water is not limiting. - Under natural field conditions, lack of precipitation may not protect semi-natural vegetation from O{sub 3} effects on leaf gas exchange.

  5. Effects of elevated ozone on leaf δ13C and leaf conductance of plant species grown in semi-natural grassland with or without irrigation

    International Nuclear Information System (INIS)

    Jaeggi, M.; Saurer, M.; Volk, M.; Fuhrer, J.

    2005-01-01

    Stable carbon isotope ratios (δ 13 C) and leaf conductance (g s ) were measured (2002, 2003) in Holcus lanatus L., Plantago lanceolata L. Ranunculus friesianus (Jord.), and Trifolium pratense L. at two levels of ozone (O 3 ) with or without irrigation. In non-irrigated control plots, R. friesianus showed the least negative δ 13 C, and the smallest response to the treatments. Irrigation caused more negative δ 13 C, especially in H. lanatus. Irrespective of irrigation, O 3 increased δ 13 C in relationship to a decrease in g s in P. lanceolata and T. pratense. The strongest effect of O 3 on δ 13 C occurred in the absence of irrigation, suggesting that under field conditions lack of moisture in the top soil does not always lead to protection from O 3 uptake. It is concluded that in species such as T. pratense plants can maintain stomatal O 3 uptake during dry periods when roots can reach deeper soil layers where water is not limiting. - Under natural field conditions, lack of precipitation may not protect semi-natural vegetation from O 3 effects on leaf gas exchange

  6. Isolation and identification mould micoflora inhabiting plant leaf litter from Mount Lawu, Surakarta, Central Java

    Directory of Open Access Journals (Sweden)

    MUHAMMAD ILYAS

    2007-04-01

    Full Text Available A study on isolation and identification mould inhabiting plant leaf litter had been conducted. The objective of the study was to isolate and identify mould inhabiting plant leaf litter from Mount Lawu, Surakarta, Central Java. The mould isolation was based on washing and filtering with membrane isolation method. The result showed that 39 moulds generas with 55 species varians, one group identified in class level, and three groups of unidentified mould isolates had been isolated. Taxas distributions showed that there were endophyte and phytopatogen mould isolates had been isolated such as Fusarium, Pestalotiopsis, Phoma, and Coelomycetes. However, typical soil taxa and common saprobic fungi such as Aspergillus, Cunninghamella, Mucor, Paecilomyces, Penicillium, Rhizopus, and Trichoderma remain dominated the resulted isolates.

  7. Identification of the vascular plants of Churchill, Manitoba, using a DNA barcode library

    Directory of Open Access Journals (Sweden)

    Kuzmina Maria L

    2012-11-01

    Full Text Available Abstract Background Because arctic plant communities are highly vulnerable to climate change, shifts in their composition require rapid, accurate identifications, often for specimens that lack diagnostic floral characters. The present study examines the role that DNA barcoding can play in aiding floristic evaluations in the arctic by testing the effectiveness of the core plant barcode regions (rbcL, matK and a supplemental ribosomal DNA (ITS2 marker for a well-studied flora near Churchill, Manitoba. Results This investigation examined 900 specimens representing 312 of the 354 species of vascular plants known from Churchill. Sequencing success was high for rbcL: 95% for fresh specimens and 85% for herbarium samples (mean age 20 years. ITS2 worked equally well for the fresh and herbarium material (89% and 88%. However, sequencing success was lower for matK, despite two rounds of PCR amplification, which reflected less effective primer binding and sensitivity to the DNA degradation (76% of fresh, 45% of herbaria samples. A species was considered as taxonomically resolved if its members showed at least one diagnostic difference from any other taxon in the study and formed a monophyletic clade. The highest species resolution (69% was obtained by combining information from all three genes. The joint sequence information for rbcL and matK distinguished 54% of 286 species, while rbcL and ITS2 distinguished 63% of 285 species. Discrimination of species within Salix, which constituted 8% of the flora, was particularly problematic. Despite incomplete resolution, the barcode results revealed 22 misidentified herbarium specimens, and enabled the identification of field specimens which were otherwise too immature to identify. Although seven cases of ITS2 paralogy were noted in the families Cyperaceae, Juncaceae and Juncaginaceae, this intergenic spacer played an important role in resolving congeneric plant species at Churchill. Conclusions Our results

  8. Identification of the vascular plants of Churchill, Manitoba, using a DNA barcode library.

    Science.gov (United States)

    Kuzmina, Maria L; Johnson, Karen L; Barron, Hannah R; Hebert, Paul Dn

    2012-11-28

    Because arctic plant communities are highly vulnerable to climate change, shifts in their composition require rapid, accurate identifications, often for specimens that lack diagnostic floral characters. The present study examines the role that DNA barcoding can play in aiding floristic evaluations in the arctic by testing the effectiveness of the core plant barcode regions (rbcL, matK) and a supplemental ribosomal DNA (ITS2) marker for a well-studied flora near Churchill, Manitoba. This investigation examined 900 specimens representing 312 of the 354 species of vascular plants known from Churchill. Sequencing success was high for rbcL: 95% for fresh specimens and 85% for herbarium samples (mean age 20 years). ITS2 worked equally well for the fresh and herbarium material (89% and 88%). However, sequencing success was lower for matK, despite two rounds of PCR amplification, which reflected less effective primer binding and sensitivity to the DNA degradation (76% of fresh, 45% of herbaria samples). A species was considered as taxonomically resolved if its members showed at least one diagnostic difference from any other taxon in the study and formed a monophyletic clade. The highest species resolution (69%) was obtained by combining information from all three genes. The joint sequence information for rbcL and matK distinguished 54% of 286 species, while rbcL and ITS2 distinguished 63% of 285 species. Discrimination of species within Salix, which constituted 8% of the flora, was particularly problematic. Despite incomplete resolution, the barcode results revealed 22 misidentified herbarium specimens, and enabled the identification of field specimens which were otherwise too immature to identify. Although seven cases of ITS2 paralogy were noted in the families Cyperaceae, Juncaceae and Juncaginaceae, this intergenic spacer played an important role in resolving congeneric plant species at Churchill. Our results provided fast and cost-effective solution to create a

  9. Identification of antibacterial constituents from the indigenous Australian medicinal plant Eremophila duttonii F. Muell. (Myoporaceae).

    Science.gov (United States)

    Smith, Joshua E; Tucker, David; Watson, Kenneth; Jones, Graham Lloyd

    2007-06-13

    This paper reports on the isolation and identification of antibacterial constituents from the indigenous Australian medicinal plant Eremophila duttonii F. Muell. (Myoporaceae). Preparations derived from this plant are used by indigenous populations in the topical treatment of minor wounds, otitis and ocular complaints, and as a gargle for sore throat. Several authors have reported extracts of this plant to effect rapid bacteriolysis and inhibit growth of a wide range of Gram-positive micro-organisms. In other studies involving screening of native medicinal plants for antibacterial activity, extracts of Eremophila duttonii have been reported to consistently exhibit the highest potency amongst all species included. From a hexane extract, we identified two diterpenes of the serrulatane class, the principal constituents responsible for antibacterial activity and present as major constituents of the resinous leaf cuticle: serrulat-14-en-7,8,20-triol (1) and serrulat-14-en-3,7,8,20-tetraol (2). In addition, a hydroxylated furanosesquiterpene with mild antibacterial activity which appeared to be a novel compound was isolated from the extract and tentatively identified as 4-hydroxy-4-methyl-1-(2,3,4,5-tetrahydro-5-methyl[2,3'-bifuran]-5-yl) pentan-2-one. Minimum inhibitory concentrations for each of the compounds against three Gram-positive bacteria: Staphylococcus aureus (ATCC 29213), Staphylococcus epidermidis (ATCC 12228) and Streptococcus pneumoniae (ARL 10582), were determined using a micro-titre plate broth dilution assay.

  10. Hazard Identification and Risk Assessment in Water Treatment Plant considering Environmental Health and Safety Practice

    Science.gov (United States)

    Falakh, Fajrul; Setiani, Onny

    2018-02-01

    Water Treatment Plant (WTP) is an important infrastructure to ensure human health and the environment. In its development, aspects of environmental safety and health are of concern. This paper case study was conducted at the Water Treatment Plant Company in Semarang, Central Java, Indonesia. Hazard identification and risk assessment is one part of the occupational safety and health program at the risk management stage. The purpose of this study was to identify potential hazards using hazard identification methods and risk assessment methods. Risk assessment is done using criteria of severity and probability of accident. The results obtained from this risk assessment are 22 potential hazards present in the water purification process. Extreme categories that exist in the risk assessment are leakage of chlorine and industrial fires. Chlorine and fire leakage gets the highest value because its impact threatens many things, such as industrial disasters that could endanger human life and the environment. Control measures undertaken to avoid potential hazards are to apply the use of personal protective equipment, but management will also be better managed in accordance with hazard control hazards, occupational safety and health programs such as issuing work permits, emergency response training is required, Very useful in overcoming potential hazards that have been determined.

  11. Hazard Identification and Risk Assessment in Water Treatment Plant considering Environmental Health and Safety Practice

    Directory of Open Access Journals (Sweden)

    Falakh Fajrul

    2018-01-01

    Full Text Available Water Treatment Plant (WTP is an important infrastructure to ensure human health and the environment. In its development, aspects of environmental safety and health are of concern. This paper case study was conducted at the Water Treatment Plant Company in Semarang, Central Java, Indonesia. Hazard identification and risk assessment is one part of the occupational safety and health program at the risk management stage. The purpose of this study was to identify potential hazards using hazard identification methods and risk assessment methods. Risk assessment is done using criteria of severity and probability of accident. The results obtained from this risk assessment are 22 potential hazards present in the water purification process. Extreme categories that exist in the risk assessment are leakage of chlorine and industrial fires. Chlorine and fire leakage gets the highest value because its impact threatens many things, such as industrial disasters that could endanger human life and the environment. Control measures undertaken to avoid potential hazards are to apply the use of personal protective equipment, but management will also be better managed in accordance with hazard control hazards, occupational safety and health programs such as issuing work permits, emergency response training is required, Very useful in overcoming potential hazards that have been determined.

  12. Monitoring in South African grasslands

    CSIR Research Space (South Africa)

    Mentis, MT

    1984-12-01

    Full Text Available The main purpose of this document is to propose how ecological monitoring might be developed in the Grassland Biome of South Africa. Monitoring is defined as the maintenance of regular surveillance to test the null hypothesis of no change...

  13. Terrestrial ecology. Comprehensive study of the grassland biome

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Terrestrial ecology and grassland biome studies are designed to characterize the biota of the Hanford Reservation, elucidate seasonal dynamics of plant productivity, decomposition and mineral behavior patterns of important plant communities, and, to study the response of these communities to important natural environmental stresses, such as weather, wildfire and man-induced alterations of communities (influenced by grazing cattle and severe mechanical disturbance of the soil, such as affected by plowing or burial of waste materials or construction activities). A detailed account of the important findings of a 5-yr study is currently being prepared by the terrestrial ecology section staff for publication as a contribution to the International Biological Program Grassland Biome project

  14. The role of plant mycorrhizal type and status in modulating the relationship between plant and arbuscular mycorrhizal fungal communities.

    Science.gov (United States)

    Neuenkamp, Lena; Moora, Mari; Öpik, Maarja; Davison, John; Gerz, Maret; Männistö, Minna; Jairus, Teele; Vasar, Martti; Zobel, Martin

    2018-01-25

    Interactions between communities of plants and arbuscular mycorrhizal (AM) fungi shape fundamental ecosystem properties. Experimental evidence suggests that compositional changes in plant and AM fungal communities should be correlated, but empirical data from natural ecosystems are scarce. We investigated the dynamics of covariation between plant and AM fungal communities during three stages of grassland succession, and the biotic and abiotic factors shaping these dynamics. Plant communities were characterised using vegetation surveys. AM fungal communities were characterised by 454-sequencing of the small subunit rRNA gene and identification against the AM fungal reference database MaarjAM. AM fungal abundance was estimated using neutral-lipid fatty acids (NLFAs). Multivariate correlation analysis (Procrustes) revealed a significant relationship between plant and AM fungal community composition. The strength of plant-AM fungal correlation weakened during succession following cessation of grassland management, reflecting changes in the proportion of plants exhibiting different AM status. Plant-AM fungal correlation was strong when the abundance of obligate AM plants was high, and declined as the proportion of facultative AM plants increased. We conclude that the extent to which plants rely on AM symbiosis can determine how tightly communities of plants and AM fungi are interlinked, regulating community assembly of both symbiotic partners. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

  15. Are Agrofuels a conservation threat or opportunity for grassland birds in the United States?

    Science.gov (United States)

    Robertson, Bruce A.; Rice, Robert A.; Ribic, Christine; Babcock, Bruce A.; Landis, Douglas A.; Herkert, James R.; Fletcher, Robert J.; Fontaine, Joseph J; Doran, Patrick J.; Schemske, Douglas W.

    2012-01-01

    In the United States, government-mandated growth in the production of crops dedicated to biofuel (agrofuels) is predicted to increase the demands on existing agricultural lands, potentially threatening the persistence of populations of grassland birds they support. We review recently published literature and datasets to (1) examine the ability of alternative agrofuel crops and their management regimes to provide habitat for grassland birds, (2) determine how crop placement in agricultural landscapes and agrofuel-related land-use change will affect grassland birds, and (3) identify critical research and policy-development needs associated with agrofuel production. We find that native perennial plants proposed as feedstock for agrofuel (switchgrass, Panicum virgatum, and mixed grass—forb prairie) have considerable potential to provide new habitat to a wide range of grassland birds, including rare and threatened species. However, industrialization of agrofuel production that maximizes biomass, homogenizes vegetation structure, and results in the cultivation of small fields within largely forested landscapes is likely to reduce species richness and/or abundance of grassland-dependent birds. Realizing the potential benefits of agrofuel production for grassland birds' conservation will require the development of new policies that encourage agricultural practices specifically targeting the needs of grassland specialists. The broad array of grower-incentive programs in existence may deliver new agrofuel policies effectively but will require coordination at a spatial scale broader than currently practiced, preferably within an adaptive-management framework.

  16. [Community structure and diversity of soil arthropods in naturally restored sandy grasslands after grazing].

    Science.gov (United States)

    Liu, Ren-tao; Zhao, Ha-lin; Zhao, Xue-yong

    2010-11-01

    Taking the Naiman Desertification Research Station under Chinese Academy of Sciences as a base, an investigation was conducted on the community structure of soil arthropods in the naturally restored sandy grasslands after different intensity grazing disturbance, with the effects of vegetation and soil on this community structure approached. In the non-grazing grassland, soil arthropods were rich in species and more in individuals, and had the highest diversity. In the restored grassland after light grazing, soil arthropods had the lowest evenness and diversity. In the restored grassland after moderate grazing, the individuals of soil arthropods were lesser but the major groups were more, and the evenness and diversity were higher. In the restored grassland after heavy grazing, the individuals of soil arthropods were more but the major groups were lesser, and the diversity was higher. Plant individuals' number, vegetation height and coverage, and soil alkalinity were the main factors affecting the soil arthropod community in naturally restored grasslands after different intensity grazing disturbance. It was implied that after 12-year exclosure of grassland, soil arthropod community could be recovered to some degree, while grazing disturbance had long-term negative effects on the arthropod community.

  17. Neuro-fuzzy models for systems identification applied to the operation of nuclear power plants

    International Nuclear Information System (INIS)

    Alves, Antonio Carlos Pinto Dias

    2000-09-01

    A nuclear power plant has a myriad of complex system and sub-systems that, working cooperatively, make the control of the whole plant. Nevertheless their operation be automatic most of the time, the integral understanding of their internal- logic can be away of the comprehension of even experienced operators because of the poor interpretability those controls offer. This difficulty does not happens only in nuclear power plants but in almost every a little more complex control system. Neuro-fuzzy models have been used for the last years in a attempt of suppress these difficulties because of their ability of modelling in linguist form even a system which behavior is extremely complex. This is a very intuitive human form of interpretation and neuro-fuzzy model are gathering increasing acceptance. Unfortunately, neuro-fuzzy models can grow up to become of hard interpretation because of the complexity of the systems under modelling. In general, that growing occurs in function of redundant rules or rules that cover a very little domain of the problem. This work presents an identification method for neuro-fuzzy models that not only allows models grow in function of the existent complexity but that beforehand they try to self-adapt to avoid the inclusion of new rules. This form of construction allowed to arrive to highly interpretative neuro-fuzzy models even of very complex systems. The use of this kind of technique in modelling the control of the pressurizer of a PWR nuclear power plant allowed verify its validity and how neuro-fuzzy models so built can be useful in understanding the automatic operation of a nuclear power plant. (author)

  18. Stable carbon isotope analysis of soil organic matter illustrates vegetation change at the grassland/woodland boundary in southeastern Arizona, USA.

    Science.gov (United States)

    McPherson, G R; Boutton, T W; Midwood, A J

    1993-02-01

    In southeastern Arizona, Prosopis juliflora (Swartz) DC. and Quercus emoryi Torr. are the dominant woody species at grassland/woodland boundaries. The stability of the grassland/woodland boundary in this region has been questioned, although there is no direct evidence to confirm that woodland is encroaching into grassland or vice versa. We used stable carbon isotope analysis of soil organic matter to investigate the direction and magnitude of vegetation change along this ecotone. δ 13 C values of soil organic matter and roots along the ecotone indicated that both dominant woody species (C 3 ) are recent components of former grasslands (C 4 ), consistent with other reports of recent increases in woody plant abundance in grasslands and savannas throughout the world. Data on root biomass and soil organic matter suggest that this increase in woody plant abundance in grasslands and savannas may increase carbon storage in these ecosystems, with implications for the global carbon cycle.

  19. Three-Step Test System for the Identification of Novel GABAA Receptor Modulating Food Plants.

    Science.gov (United States)

    Sahin, Sümeyye; Eulenburg, Volker; Kreis, Wolfgang; Villmann, Carmen; Pischetsrieder, Monika

    2016-12-01

    Potentiation of γ-amino butyric acid (GABA)-induced GABA A receptor (GABA A R) activation is a common pathway to achieve sedative, sleep-enhancing, anxiolytic, and antidepressant effects. Presently, a three-component test system was established for the identification of novel GABA A R modulating food plants. In the first step, potentiation of GABA-induced response of the GABA A R was analysed by two-electrode voltage clamp (TEVC) for activity on human α1β2-GABA A R expressed in Xenopus laevis oocytes. Positively tested food plants were then subjected to quantification of GABA content by high-performance liquid chromatography with fluorescence detection (HPLC-FLD) to exclude test foods, which evoke a TEVC-response by endogenous GABA. In the third step, specificity of GABA A -modulating activity was assessed by TEVC analysis of Xenopus laevis oocytes expressing the homologous glycine receptor (GlyR). The three-component test was then applied to screen 10 aqueous extracts of food plants for their GABA A R activity. Thus, hop cones (Humulus lupulus) and Sideritis sipylea were identified as the most potent specific GABA A R modulators eliciting significant potentiation of the current by 182 ± 27 and 172 ± 19 %, respectively, at the lowest concentration of 0.5 μg/mL. The extracts can now be further evaluated by in vivo studies and by structural evaluation of the active components.

  20. Identification of olivetolic acid cyclase from Cannabis sativa reveals a unique catalytic route to plant polyketides.

    Science.gov (United States)

    Gagne, Steve J; Stout, Jake M; Liu, Enwu; Boubakir, Zakia; Clark, Shawn M; Page, Jonathan E

    2012-07-31

    Δ(9)-Tetrahydrocannabinol (THC) and other cannabinoids are responsible for the psychoactive and medicinal properties of Cannabis sativa L. (marijuana). The first intermediate in the cannabinoid biosynthetic pathway is proposed to be olivetolic acid (OA), an alkylresorcinolic acid that forms the polyketide nucleus of the cannabinoids. OA has been postulated to be synthesized by a type III polyketide synthase (PKS) enzyme, but so far type III PKSs from cannabis have been shown to produce catalytic byproducts instead of OA. We analyzed the transcriptome of glandular trichomes from female cannabis flowers, which are the primary site of cannabinoid biosynthesis, and searched for polyketide cyclase-like enzymes that could assist in OA cyclization. Here, we show that a type III PKS (tetraketide synthase) from cannabis trichomes requires the presence of a polyketide cyclase enzyme, olivetolic acid cyclase (OAC), which catalyzes a C2-C7 intramolecular aldol condensation with carboxylate retention to form OA. OAC is a dimeric α+β barrel (DABB) protein that is structurally similar to polyketide cyclases from Streptomyces species. OAC transcript is present at high levels in glandular trichomes, an expression profile that parallels other cannabinoid pathway enzymes. Our identification of OAC both clarifies the cannabinoid pathway and demonstrates unexpected evolutionary parallels between polyketide biosynthesis in plants and bacteria. In addition, the widespread occurrence of DABB proteins in plants suggests that polyketide cyclases may play an overlooked role in generating plant chemical diversity.

  1. Research on the Mechanism of Cross Regional Grassland Ecological Compensation

    Science.gov (United States)

    Yang, Ran; Ma, Jun

    2018-01-01

    In recent years, grassland environmental damage has become serious, and grassland resources protection task has become heavy, grassland ecological compensation has become an effective way to solve this problem; but the current grassland ecological compensation standards were low, the effect is poor. The fundamental reason is the model of administrative division destroys the integrity of grassland. Based on the analysis of the status quo of grassland compensation, this paper tries to protect the grassland integrity, breaks the administrative division restriction, implements the space regulation, constructs the framework of cross-regional grassland ecological compensation mechanism, describes its operation process. It provides new way to realize the sustainable development of the grassland environment.

  2. Identification of invasive and expansive plant species based on airborne hyperspectral and ALS data

    Science.gov (United States)

    Szporak-Wasilewska, Sylwia; Kuc, Gabriela; Jóźwiak, Jacek; Demarchi, Luca; Chormański, Jarosław; Marcinkowska-Ochtyra, Adriana; Ochtyra, Adrian; Jarocińska, Anna; Sabat, Anita; Zagajewski, Bogdan; Tokarska-Guzik, Barbara; Bzdęga, Katarzyna; Pasierbiński, Andrzej; Fojcik, Barbara; Jędrzejczyk-Korycińska, Monika; Kopeć, Dominik; Wylazłowska, Justyna; Woziwoda, Beata; Michalska-Hejduk, Dorota; Halladin-Dąbrowska, Anna

    2017-04-01

    The aim of Natura 2000 network is to ensure the long term survival of most valuable and threatened species and habitats in Europe. The encroachment of invasive alien and expansive native plant species is among the most essential threat that can cause significant damage to protected habitats and their biodiversity. The phenomenon requires comprehensive and efficient repeatable solutions that can be applied to various areas in order to assess the impact on habitats. The aim of this study is to investigate of the issue of invasive and expansive plant species as they affect protected areas at a larger scale of Natura 2000 network in Poland. In order to determine the scale of the problem we have been developing methods of identification of invasive and expansive species and then detecting their occurrence and mapping their distribution in selected protected areas within Natura 2000 network using airborne hyperspectral and airborne laser scanning data. The aerial platform used consists of hyperspectral HySpex scanner (451 bands in VNIR and SWIR), Airborne Laser Scanner (FWF) Riegl Lite Mapper and RGB camera. It allowed to obtain simultaneous 1 meter resolution hyperspectral image, 0.1 m resolution orthophotomaps and point cloud data acquired with 7 points/m2. Airborne images were acquired three times per year during growing season to account for plant seasonal change (in May/June, July/August and September/October 2016). The hyperspectral images were radiometrically, geometrically and atmospherically corrected. Atmospheric correction was performed and validated using ASD FieldSpec 4 measurements. ALS point cloud data were used to generate several different topographic, vegetation and intensity products with 1 m spatial resolution. Acquired data (both hyperspectral and ALS) were used to test different classification methods including Mixture Tuned Matched Filtering (MTMF), Spectral Angle Mapper (SAM), Random Forest (RF), Support Vector Machines (SVM), among others

  3. Efficient Approach for Harmonic Resonance Identification of Large Wind Power Plants

    DEFF Research Database (Denmark)

    Ebrahimzadeh, Esmaeil; Blaabjerg, Frede; Wang, Xiongfei

    2016-01-01

    Unlike conventional power systems where the resonance frequencies are mainly determined by the passive components parameters, large Wind Power Plants (WPPs) may introduce additional harmonic resonances because of the interactions of the wideband control systems of power converters with each other...... and with passive components. This paper presents an efficient approach for identification of harmonic resonances in large WPPs containing power electronic converters, cable, transformer, capacitor banks, shunt reactors, etc. The proposed approach introduces a large WPP as a Multi-Input Multi-Output (MIMO) control...... system by considering the linearized models of the inner control loops of grid-side converters. Therefore, the resonance frequencies of the WPP resulting from passive components and the control loop interactions are identified based on the determinant of the transfer function matrix of the introduced...

  4. Identification of Bottlenecks in the Plant Life Cycle for Sustainable Conservation of Rare and Endangered Species

    Directory of Open Access Journals (Sweden)

    Giovanna Aronne

    2017-07-01

    Full Text Available Long term survival of a species relies on maintenance of genetic variability and natural selection by means of successful reproduction and generation turnover. Although, basic to monitor the conservation status of a plant species, life history data are rarely available even for threatened species due to the gap between the large amount of information required and the limits in terms of time and available economic resources to gather these data. Here, the focus on bottlenecks in life-cycle of rare endangered plant species is proposed as a resolving approach to address the challenges of feasible conservation actions. Basic considerations for this approach are: (a all biological and ecological studies on plant species can be scientifically important, but not all of them are equally relevant to conservation planning and management requirements; (b under a changing environment, long term survival of a species relies on generation turnover; (c for conservation purposes, priority should be given to studies aimed to focus on bottlenecks in the succession of generations because they prevent, or slow down natural selection processes. The proposed procedure, named Systematic Hazard Analysis of Rare-endangered Plants (SHARP, consists of a preliminary survey of the already available information on the species and two main components. The first component is the identification of the bottlenecks in the life cycle by means of field surveys. The second is the diagnosis of the causes of the bottleneck by appropriate experimental methods. The target is to provide researchers, managers and practitioners with substantiated indications for sustainable conservation measures.

  5. Identification of Methylosome Components as Negative Regulators of Plant Immunity Using Chemical Genetics.

    Science.gov (United States)

    Huang, Shuai; Balgi, Aruna; Pan, Yaping; Li, Meng; Zhang, Xiaoran; Du, Lilin; Zhou, Ming; Roberge, Michel; Li, Xin

    2016-12-05

    Nucleotide-binding leucine-rich repeat (NLR) proteins serve as immune receptors in both plants and animals. To identify components required for NLR-mediated immunity, we designed and carried out a chemical genetics screen to search for small molecules that can alter immune responses in Arabidopsis thaliana. From 13 600 compounds, we identified Ro 8-4304 that was able to specifically suppress the severe autoimmune phenotypes of chs3-2D (chilling sensitive 3, 2D), including the arrested growth morphology and heightened PR (Pathogenesis Related) gene expression. Further, six Ro 8-4304 insensitive mutants were uncovered from the Ro 8-4304-insensitive mutant (rim) screen using a mutagenized chs3-2D population. Positional cloning revealed that rim1 encodes an allele of AtICln (I, currents; Cl, chloride; n, nucleotide). Genetic and biochemical analysis demonstrated that AtICln is in the same protein complex with the methylosome components small nuclear ribonucleoprotein D3b (SmD3b) and protein arginine methyltransferase 5 (PRMT5), which are required for the biogenesis of small nuclear ribonucleoproteins (snRNPs) involved in mRNA splicing. Double mutant analysis revealed that SmD3b is also involved in the sensitivity to Ro 8-4304, and the prmt5-1 chs3-2D double mutant is lethal. Loss of AtICln, SmD3b, or PRMT5 function results in enhanced disease resistance against the virulent oomycete pathogen Hyaloperonospora arabidopsidis Noco2, suggesting that mRNA splicing plays a previously unknown negative role in plant immunity. The successful implementation of a high-throughput chemical genetic screen and the identification of a small-molecule compound affecting plant immunity indicate that chemical genetics is a powerful tool to study whole-organism plant defense pathways. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

  6. Identification of Meloidogyne species associated with upland ornamentals plants in Costa Rica.

    Directory of Open Access Journals (Sweden)

    Stefany Solano-González

    2015-06-01

    Full Text Available The objective of this study was to identify nematodes species of the genus Meloidogyne associated with upland ornamental plants. We sampled ten ornamental species in a commercial nursery in San Isidro, Heredia, Costa Rica between 2011-2012. Morphometric measurements of the stylet length, the tail length, and the hyaline region of J2s, as well as perineal patterns of egg-carrying females were used for identification, Genomic DNA was extracted from single J2s and molecular analyses were performed by amplifying the intergenic region between cytochrome oxidase subunit II of the COII and the long subunit of the ARN ribosomal genes by PCR-RFLP. Combining these methods allowed identification of five species of nematodes of the genus Meloidogyne (M. arenaria, M. hapla, M. hispanica, M. incognita and M. javanica, and new restriction enzyme patterns were reported for M. hapla and M. javanica using AluI. Additionally, a preliminary report of M. hispanica was described by sequencing the 28S and 18S regions.

  7. Identification of Meloidogyne species associated with uptall ornamentals plants in Costa Rica

    International Nuclear Information System (INIS)

    Solano-Gonzalez, Stefany; Esquivel-Hernandez, Alejandro; Molina-Bravo, Ramon; Morera-Brenes, Bernal

    2015-01-01

    Nematodes species of the genus Meloidogyne associated with upland ornamental plants were identified. Ten ornamental species in a commercial nursery were sampled in San Isidro, Heredia, Costa Rica between 2011-2012. Morphometric measurements of the stylet length, the trail length, and the hyaline region of J_2s as well as perineal patterns of egg-carrying females were used for identification, Genomic DNA was extracted from single J_2s and molecular analyses were performed by amplifying the intergenic region between cytochrome oxidase subunit II of the COII and the long subunit of the ARN ribosomal genes by PCR-RFLP. Combining these methods allowed identification of five species of nematodes of the genus Meloidogyne (M. arenaria, M. hapla, M. hispanica, M. incognita and M. javanica), and new restriction enzyme patterns were reported for M. hapla and M. javanica using AluI. Additionally a preliminary report of M. hispanica was described by sequencing the 28S and 18S regions. (author) [es

  8. Potential of MALDI-TOF mass spectrometry as a rapid detection technique in plant pathology: identification of plant-associated microorganisms.

    Science.gov (United States)

    Ahmad, Faheem; Babalola, Olubukola O; Tak, Hamid I

    2012-09-01

    Plant diseases caused by plant pathogens substantially reduce crop production every year, resulting in massive economic losses throughout the world. Accurate detection and identification of plant pathogens is fundamental to plant pathogen diagnostics and, thus, plant disease management. Diagnostics and disease-management strategies require techniques to enable simultaneous detection and quantification of a wide range of pathogenic and non-pathogenic microorganisms. Over the past decade, rapid development of matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) techniques for characterization of microorganisms has enabled substantially improved detection and identification of microorganisms. In the biological sciences, MALDI-TOF MS is used to analyze specific peptides or proteins directly desorbed from intact bacteria, fungal spores, nematodes, and other microorganisms. The ability to record biomarker ions, in a broad m/z range, which are unique to and representative of individual microorganisms, forms the basis of taxonomic identification of microorganisms by MALDI-TOF MS. Recent advances in mass spectrometry have initiated new research, i.e. analysis of more complex microbial communities. Such studies are just beginning but have great potential for elucidation not only of the interactions between microorganisms and their host plants but also those among different microbial taxa living in association with plants. There has been a recent effort by the mass spectrometry community to make data from large scale mass spectrometry experiments publicly available in the form of a centralized repository. Such a resource could enable the use of MALDI-TOF MS as a universal technique for detection of plant pathogens and non-pathogens. The effects of experimental conditions are sufficiently understood, reproducible spectra can be obtained from computational database search, and microorganisms can be rapidly characterized by genus, species

  9. Grassland response to herbicides and seeding of native grasses 6 years posttreatment

    Science.gov (United States)

    Bryan A. Endress; Catherine G. Parks; Bridgett J. Naylor; Steven R. Radosevich; Mark. Porter

    2012-01-01

    Herbicides are the primary method used to control exotic, invasive plants. This study evaluated restoration efforts applied to grasslands dominated by an invasive plant, sulfur cinquefoil, 6 yr after treatments. Of the five herbicides we evaluated, picloram continued to provide the best control of sulfur cinquefoil over 6 yr. We found the timing of picloram...

  10. Vegetation in clear-cuts depends on previous land use: a century-old grassland legacy

    Science.gov (United States)

    Jonason, Dennis; Ibbe, Mathias; Milberg, Per; Tunér, Albert; Westerberg, Lars; Bergman, Karl-Olof

    2014-01-01

    Plant species richness in central and northern European seminatural grasslands is often more closely linked to past than present habitat configuration, which is indicative of an extinction debt. In this study, we investigate whether signs of historical grassland management can be found in clear-cuts after at least 80 years as coniferous production forest by comparing floras between clear-cuts with a history as meadow and as forest in the 1870s in Sweden. Study sites were selected using old land-use maps and data on present-day clear-cuts. Species traits reflecting high capacities for dispersal and persistence were used to explain any possible links between the plants and the historical land use. Clear-cuts that were formerly meadow had, on average, 36% higher species richness and 35% higher richness of grassland indicator species, as well as a larger overall seed mass and lower anemochory, compared to clear-cuts with history as forest. We suggest that the plants in former meadows never disappeared after afforestation but survived as remnant populations. Many contemporary forests in Sweden were managed as grasslands in the 1800s. As conservation of remaining grassland fragments will not be enough to reduce the existing extinction debts of the flora, these young forests offer opportunities for grassland restoration at large scales. Our study supports the concept of remnant populations and highlights the importance of considering historical land use for understanding the distribution of grassland plant species in fragmented landscapes, as well as for policy-making and conservation. PMID:25540690

  11. Relationships between botanical and chemical composition of forages: a multivariate approach to grasslands in the Western Italian Alps.

    Science.gov (United States)

    Ravetto Enri, Simone; Renna, Manuela; Probo, Massimiliano; Lussiana, Carola; Battaglini, Luca M; Lonati, Michele; Lombardi, Giampiero

    2017-03-01

    Plant composition of species-rich mountain grasslands can affect the sensorial and chemical attributes of dairy and meat products, with implications for human health. A multivariate approach was used to analyse the complex relationships between vegetation characteristics (botanical composition and plant community variables) and chemical composition (proximate constituents and fatty acid profile) in mesophilic and dry vegetation ecological groups, comprising six different semi-natural grassland types in the Western Italian Alps. Mesophilic and dry grasslands were comparable in terms of phenology, biodiversity indices and proportion of botanical families. The content of total fatty acids and that of the most abundant fatty acids (alpha-linolenic, linoleic and palmitic acids) were mainly associated to nutrient-rich plant species, belonging to the mesophilic grassland ecological group. Mesophilic grasslands showed also higher values of crude protein, lower values of fibre content and they were related to higher pastoral values of vegetation compared to dry grasslands. The proximate composition and fatty acid profile appeared mainly single species dependent rather than botanical family dependent. These findings highlight that forage from mesophilic grasslands can provide higher nutritive value for ruminants and may be associated to ruminant-derived food products with a healthier fatty acid profile. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  12. Hyphenated chromatographic techniques for the rapid screening and identification of antioxidants in methanolic extracts of pharmaceutically used plants .

    NARCIS (Netherlands)

    Exarchou, V.; Fiamegos, Y.C.; Beek, van T.A.; Nanos, C.G.; Vervoort, J.J.M.

    2006-01-01

    Phytochemical analysis is an important scientific research area, which normally relies on a number of rather laborious and time-consuming techniques for compound identification. Isolation of the ingredients of plant extracts in adequate quantities for spectral and biological analysis was the basis

  13. RADIO FREQUENCY IDENTIFICATION DEVICES: EFFECTIVENESS IN IMPROVING SAFEGUARDS AT GAS-CENTRIFUGE URANIUM-ENRICHMENT PLANTS

    International Nuclear Information System (INIS)

    JOE, J.

    2007-01-01

    Recent advances in radio frequency identification devices (RFIDs) have engendered a growing interest among international safeguards experts. Potentially, RFIDs could reduce inspection work, viz. the number of inspections, number of samples, and duration of the visits, and thus improve the efficiency and effectiveness of international safeguards. This study systematically examined the applications of RFIDs for IAEA safeguards at large gas-centrifuge enrichment plants (GCEPs). These analyses are expected to help identify the requirements and desirable properties for RFIDs, to provide insights into which vulnerabilities matter most, and help formulate the required assurance tests. This work, specifically assesses the application of RFIDs for the ''Option 4'' safeguards approach, proposed by Bruce Moran, U. S. Nuclear Regulatory Commission (NRC), for large gas-centrifuge uranium-enrichment plants. The features of ''Option 4'' safeguards include placing RFIDs on all feed, product and tails (F/P/T) cylinders, along with WID readers in all FP/T stations and accountability scales. Other features of Moran's ''Option 4'' are Mailbox declarations, monitoring of load-cell-based weighing systems at the F/P/T stations and accountability scales, and continuous enrichment monitors. Relevant diversion paths were explored to evaluate how RFIDs improve the efficiency and effectiveness of safeguards. Additionally, the analysis addresses the use of RFIDs in conjunction with video monitoring and neutron detectors in a perimeter-monitoring approach to show that RFIDs can help to detect unidentified cylinders

  14. Temporal neural network for the identification of nuclear power plant transients

    International Nuclear Information System (INIS)

    Uluyol, O.; Ragheb, M.

    1993-01-01

    In this paper a layered spatiotemporal neural network is proposed for the identification of nuclear power plant transients. The developed layered spatiotemporal network is inspired by the formal avalanche structure developed by S. Grossberg and offers advantages compared with the stationary pattern approach using the perceptron paradigm. Each layer in the network is trained to recognize a separate time-dependent accident scenario. Within each scenario, the temporal behavior of the relevant parameters such as pressurizer pressure, pressurizer water volume, cold and hot legs temperatures, vessel flow, and power, are considered. Numerical cases are considered where the proposed methodology is applied to two nuclear power plant anticipated transient scenarios: the Station Blackout and the Anticipated Transient without Scram transients in a pressurized water reactor . The transient signatures used were generated by modeling the accidents using RELAP5/MOD2, a best-estimate thermal-hydraulics numerical code. The ability of the proposed layered spatiotemporal network to operate at different noise levels is investigated. Its incorporation within an Insightful Algorithm and Anticipatory Systems context for identifying and in predicting the course of nuclear transients is discussed

  15. Quantifying establishment limitations during the ecological restoration of species-rich Nardus grassland

    NARCIS (Netherlands)

    Daele, Van Frederik; Wasof, Safaa; Demey, Andreas; Schelfhout, Stephanie; Schrijver, De A.; Baeten, Lander; Ruijven, van Jasper; Mertens, Jan; Verheyen, Kris

    2017-01-01

    Aims: Successful establishment of species-rich Nardus grasslands on ex-agricultural land requires identification and removal of barriers to effective seed germination and seedling survival. Therefore, we investigate how germination and early development are affected by soil conditions from

  16. The biological transport of radionuclides in grassland and freshwater ecosystems

    International Nuclear Information System (INIS)

    Rudge, S.A.

    1989-12-01

    This thesis examines the biological transport of radionuclides through terrestrial and aquatic ecosystems, with particular reference to radiocaesium. The semi-natural grassland habitat was located at Drigg, W. Cumbria, contaminated primarily by radioactive fallout, from several sources over the past decade. Advantage was made of the deposition of radionuclides from the Chernobyl reactor incident, which occurred during the early stages of the investigation. The study examined the distribution of radiocaesium for the major components of the grassland ecosystem, within the soil-plant-invertebrate-small mammal food chain. Data concerning temporal fluctuation of radionuclide transfer factors between food chain components are presented. The final section examines the spatial distribution of radiocaesium in sediment and the freshwater eel (Anguilla anguilla) in a small stream contaminated by radioactive effluent. The relationship between activity levels in eels and the sediments in which they rest and forage was investigated. Factors influencing uptake of radiocaesium in freshwater fish were also examined. (author)

  17. Effects of Government Grassland Conservation Policy on Household Livelihoods and Dependence on Local Grasslands: Evidence from Inner Mongolia, China

    NARCIS (Netherlands)

    Du, Bingzhen; Zhen, Lin; Yan, Huimin; Groot, de Dolf

    2016-01-01

    Grassland degradation intensifies human-environment conflicts and adversely affects local residents’ livelihoods. To reduce grassland degradation in Inner Mongolia, China, the government has enforced (since 1998) a series of grassland conservation and management policies that restrict the use of

  18. Water relations in grassland and desert ecosystems exposed to elevated atmospheric CO2.

    Science.gov (United States)

    Morgan, J A; Pataki, D E; Körner, C; Clark, H; Del Grosso, S J; Grünzweig, J M; Knapp, A K; Mosier, A R; Newton, P C D; Niklaus, P A; Nippert, J B; Nowak, R S; Parton, W J; Polley, H W; Shaw, M R

    2004-06-01

    Atmospheric CO2 enrichment may stimulate plant growth directly through (1) enhanced photosynthesis or indirectly, through (2) reduced plant water consumption and hence slower soil moisture depletion, or the combination of both. Herein we describe gas exchange, plant biomass and species responses of five native or semi-native temperate and Mediterranean grasslands and three semi-arid systems to CO2 enrichment, with an emphasis on water relations. Increasing CO2 led to decreased leaf conductance for water vapor, improved plant water status, altered seasonal evapotranspiration dynamics, and in most cases, periodic increases in soil water content. The extent, timing and duration of these responses varied among ecosystems, species and years. Across the grasslands of the Kansas tallgrass prairie, Colorado shortgrass steppe and Swiss calcareous grassland, increases in aboveground biomass from CO2 enrichment were relatively greater in dry years. In contrast, CO2-induced aboveground biomass increases in the Texas C3/C4 grassland and the New Zealand pasture seemed little or only marginally influenced by yearly variation in soil water, while plant growth in the Mojave Desert was stimulated by CO2 in a relatively wet year. Mediterranean grasslands sometimes failed to respond to CO2-related increased late-season water, whereas semiarid Negev grassland assemblages profited. Vegetative and reproductive responses to CO2 were highly varied among species and ecosystems, and did not generally follow any predictable pattern in regard to functional groups. Results suggest that the indirect effects of CO2 on plant and soil water relations may contribute substantially to experimentally induced CO2-effects, and also reflect local humidity conditions. For landscape scale predictions, this analysis calls for a clear distinction between biomass responses due to direct CO2 effects on photosynthesis and those indirect CO2 effects via soil moisture as documented here.

  19. Visual identification of alkaloids in some medicinal plants: common alkaloid reagents versus bromocresol green

    Directory of Open Access Journals (Sweden)

    Shamsa F, Esfahani HR, Gamooshi RA

    2008-07-01

    Full Text Available "n Normal 0 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Background: Alkaloids are a group of nitrogenous compounds with potential effects on the physiological behavior of human and animals. Some of these compounds are considered important drugs in modern medicine, such as atropine and morphine. Plants are considered the most important source of alkaloids. Therefore, investigating the presence of alkaloids in different plants is very important. Usually, alkaloids in plants are identified by methods such as those of Dragendorf, Wagner and Meyer, among others, which require milligrams of alkaloids for identification. In the present study, a fast and sensitive procedure for detecting of alkaloids in plants is presented.   "n"nMethods: Twelve dried plants samples were investigated for the presence alkaloids. After extracting the total alkaloid into methanol using a Soxhlet extractor, a few milligrams of the extract was transferred to a separatory funnel, buffered to pH 4.7, the bromocresol green (BCG solution (10-4 M was added, mixed and extracted with CHCl3 until a yellow color was observed in the CHCl3 layer, indicating the presence of the alkaloid. The crude extracts were also investigated by the standard methods of Dragendorf, Wagner and Meyer for the presence of alkaloids.   "n"nResults: Investigation of the 12 plant samples for the presence of alkaloids by the standard reagents of Dragendorf, Wagner, and Meyer showed that only Camelia sinensis (flowers, Echium amoenum Fisch & Mey (flowers, and Stachys (aerial parts are devoid

  20. [Diversity and distribution of grasshoppers (Orthoptera: Acridoidea) in grasslands of the Southern Pampas region, Argentina].

    Science.gov (United States)

    Mariottini, Yanina; De Wysiecki, María Laura; Lange, Carlos Ernesto

    2013-03-01

    In Argentina, the grasslands of Pampas region comprise approximately 15% of the country. As in other grasslands of the world, grasshoppers are among the most important native herbivores. Their economic importance has been recognized in Argentina since the mid to late nineteenth century, since outbreaks of different species have become recurrent phenomena. Therefore, the main objective of this work was to study their diversity and distribution in grasslands of the Southern Pampas region (Laprida county, Buenos Aires province), as one of the most affected areas. The study was conducted during five seasons (2005-10). Sampling sites were represented by the most common plant communities in this area, classified in four categories: native grasslands, disturbed grasslands, implanted pastures and halophilous grasslands. The samplings were conducted from mid-spring to early autumn, with five or six samples per season. We estimated the following population descriptors: species richness (S), eveness (E), dominance (J), and diversity index (H'). In order to evaluate the similitude of the grasshopper communities present in the different plant communities, we used qualitative and quantitative coefficients of similitude. A total of 22 species of grasshoppers were collected, of which 21 belong to the family Acrididae. The subfamily Melanoplinae was the most diverse with eight species. The largest species richness was recorded in native grasslands (18). The different communities of grasshoppers had similar indices of evenness and dominance (p>0.05). Considering all plant communities, the average value of Shannon-Wiener index was 1.58+/-0.075. There was a positive correlation between evenness index and species richness (pgrasshoppers species richness, and diversity of grasshoppers. According to the qualitative indices applied, the similitude between different grasshopper communities was higher than 60%. In general, the species that had a higher frequency of occurrence showed greater

  1. Identification and conservation of important plant areas (IPAS) for the distribution of medicinal, aromatic and economic plants in the Hindukush-Himalaya mountain range

    International Nuclear Information System (INIS)

    Sher, H.; Ali, H.; Rehman, S.

    2012-01-01

    Study on the identification of Important Plant Areas (IPAs) was conducted in seven valleys of Hindukush-Himalayas mountainous ranges of Pakistan during 2005 and 2006. The principal aim of the study is to search new avenues for the conservation and sustainable utilization of threatened medicinal and economic plants and their habitats in IPAs. IPAs are sites of tremendous ecological and economic values that still exist in the world and are being managed on specific sites to study wild plant diversity. Several of such plants are used in the traditional medicines that are being used since the dawn of history to provide basic healthcare to people the world over. According to WHO, 80% of the human population of Africa still use medicinal plants in their primary healthcare. The popularity of herbal drugs is on the constant rise in many developed countries of the world, while in developing countries like Pakistan; medicinal plants contribute significantly to the income sources of people living in remote areas. Keeping such importance in view, the World Health Organization (WHO) launched a global vision in the form of 'Global Strategy for Plant Conservation' having various targets and mile stones. Target 5 of the strategy required for the global integration of the herbal medicine in health care system with proper identification of medicinal plants and the conservation of sites where such plants are found naturally, as its basic elements. In order to contribute to the specified target, WHO advised the relevant institutions to develop research plans and conservation programmes that are focused on the Global strategy in general and target 5 in specific. While complementing the appeal and contributing to its vision, a study was conducted in various eco-systems of the Pakistan's Hindukush-Himalayas region, identifying Important Plant Areas (IPAs) for their subsequent conservation and uses for scientific purposes. Site selection for the study was based on: 1). Exceptional

  2. PCR Amplification of Ribosomal DNA for Species Identification in the Plant Pathogen Genus Phytophthora

    Science.gov (United States)

    Ristaino, Jean B.; Madritch, Michael; Trout, Carol L.; Parra, Gregory

    1998-01-01

    We have developed a PCR procedure to amplify DNA for quick identification of the economically important species from each of the six taxonomic groups in the plant pathogen genus Phytophthora. This procedure involves amplification of the 5.8S ribosomal DNA gene and internal transcribed spacers (ITS) with the ITS primers ITS 5 and ITS 4. Restriction digests of the amplified DNA products were conducted with the restriction enzymes RsaI, MspI, and HaeIII. Restriction fragment patterns were similar after digestions with RsaI for the following species: P. capsici and P. citricola; P. infestans, P. cactorum, and P. mirabilis; P. fragariae, P. cinnamomi, and P. megasperma from peach; P. palmivora, P. citrophthora, P. erythroseptica, and P. cryptogea; and P. megasperma from raspberry and P. sojae. Restriction digests with MspI separated P. capsici from P. citricola and separated P. cactorum from P. infestans and P. mirabilis. Restriction digests with HaeIII separated P. citrophthora from P. cryptogea, P. cinnamomi from P. fragariae and P. megasperma on peach, P. palmivora from P. citrophthora, and P. megasperma on raspberry from P. sojae. P. infestans and P. mirabilis digests were identical and P. cryptogea and P. erythroseptica digests were identical with all restriction enzymes tested. A unique DNA sequence from the ITS region I in P. capsici was used to develop a primer called PCAP. The PCAP primer was used in PCRs with ITS 1 and amplified only isolates of P. capsici, P. citricola, and P. citrophthora and not 13 other species in the genus. Restriction digests with MspI separated P. capsici from the other two species. PCR was superior to traditional isolation methods for detection of P. capsici in infected bell pepper tissue in field samples. The techniques described will provide a powerful tool for identification of the major species in the genus Phytophthora. PMID:9501434

  3. Quantifying the pedo-ecohydrological structure and function of degraded, grassland ecosystems

    Science.gov (United States)

    Brazier, Richard E.

    2015-04-01

    Grassland ecosystems cover significant areas of the terrestrial land mass, across a range of geoclimates, from arctic tundra, through temperate and semi-arid landscapes. In very few locations, such grasslands may be termed 'pristine' in that they remain undamaged by human activities and resilient to changing climates. In far more cases, grasslands are being degraded, often irreversibly so, with significant implications for a number of ecosystem services related to water resources, soil quality, nutrient cycles, and therefore both global food and water security. This paper draws upon empirical research that has been undertaken over the last decade to characterise a range of different grasslands in terms of soil properties, vegetation structure and geomorphology and to understand how these structures or patterns might interact or control how the grassland ecosystems function. Particular emphasis is placed upon quantifying fluxes of water, within and from grasslands, but also fluxes of sediment, via the processes of soil erosion and finally fluxes of the macronutrients Nitrogen, Phosphorus and Carbon from the landscape to surface waters. Data are presented from semi-arid grasslands, which are subject to severe encroachment by woody species, temperate upland grasslands that have been 'improved' via drainage to support grazing, temperate lowland grasslands, that are unimproved (Culm or Rhôs pastures) and finally intensively managed grasslands in temperate regions, that have been significantly modified via land management practices to improve productivity. It is hypothesised that, once degraded, the structure and function of these very diverse grassland ecosystems follows the same negative trajectory, resulting in depleted soil depths, nutrient storage capacities and therefore reduced plant growth and long-term carbon sequestration. Results demonstrate that similar, but highly complex and non-linear responses to perturbation of the ecosystem are observed, regardless of

  4. High-throughput identification of ionizing radiation-sensitive plant genes and development of radiation indicator plant and radiation sensing Genechip

    International Nuclear Information System (INIS)

    Kim, Dong Sub; Kim, Jinbaek; Ha, Bokeun; Kim, Sang Hoon; Kim, Sunhee

    2013-05-01

    Physiological analysis of monocot model plant (rice) in response to ionizing radiation (cosmic-ray, gamma-ray, Ion beam). - Identification of antioxidant characters through cytochemical analysis. - Comparison of antioxidant activities in response to ionizing irradiation. - Evaluation of anthocyanin quantity in response to ionizing irradiation. Ionization energy response gene family analysis via bioinformatic validation. - Expression analysis of monocot and dicot gene families. - In silico and bioinformatic approach to elucidate gene function. Characterization and functional analysis of genes specifically expressed in response to ionizing irradiation (cosmic-ray, gamma-ray, Ion beam). - High throughput trancriptomic analysis of plants under ionizing radiation using microarray. - Promotor and cis-element analysis of genes specifically expressed in response to ionizing radiation. - Validation and function analysis of candidate genes. - Elucidation of plant mechanism of sensing and response to ionization energy. Development of bioindicator plants detecting ionization energy. - Cloning and identification of 'Radio marker genes (RMG)'. - Development of Over-expression (O/E) or Knock-out (K/O) plant using RMG. Development of Genechip as an ionization energy detector. - Expression profiling analysis of genes specifically expression in response to ionization energy. - Prepare high-conserved gene specific oligomer. - Development of ionization energy monitoring Genechip and application

  5. High-throughput identification of ionizing radiation-sensitive plant genes and development of radiation indicator plant and radiation sensing Genechip

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Sub; Kim, Jinbaek; Ha, Bokeun; Kim, Sang Hoon; Kim, Sunhee

    2013-05-15

    Physiological analysis of monocot model plant (rice) in response to ionizing radiation (cosmic-ray, gamma-ray, Ion beam). - Identification of antioxidant characters through cytochemical analysis. - Comparison of antioxidant activities in response to ionizing irradiation. - Evaluation of anthocyanin quantity in response to ionizing irradiation. Ionization energy response gene family analysis via bioinformatic validation. - Expression analysis of monocot and dicot gene families. - In silico and bioinformatic approach to elucidate gene function. Characterization and functional analysis of genes specifically expressed in response to ionizing irradiation (cosmic-ray, gamma-ray, Ion beam). - High throughput trancriptomic analysis of plants under ionizing radiation using microarray. - Promotor and cis-element analysis of genes specifically expressed in response to ionizing radiation. - Validation and function analysis of candidate genes. - Elucidation of plant mechanism of sensing and response to ionization energy. Development of bioindicator plants detecting ionization energy. - Cloning and identification of 'Radio marker genes (RMG)'. - Development of Over-expression (O/E) or Knock-out (K/O) plant using RMG. Development of Genechip as an ionization energy detector. - Expression profiling analysis of genes specifically expression in response to ionization energy. - Prepare high-conserved gene specific oligomer. - Development of ionization energy monitoring Genechip and application.

  6. A study of the carbon dynamics of Japanese grassland and forest using 14C and 13C

    International Nuclear Information System (INIS)

    Katsuno, Kazumi; Miyairi, Yosuke; Tamura, Kenji; Matsuzaki, Hiroyuki; Fukuda, Kenji

    2010-01-01

    We quantified the carbon contents of grassland and forest soil using conventional methods and studied the changes in their dynamics by measuring δ 13 C and Δ 14 C. Soil samples were taken from a neighboring Miscanthus sinensis grassland and Pinus densiflora forest in central Japan. Both had been maintained as grassland until the 1960s, when the latter was abandoned and became a pine forest by natural succession. The soil carbon content of the forest was much lower than that of the grassland, implying that the soil carbon decreased as the grassland became forest. The δ 13 C values were very similar in the grassland and forest, at approximately -20 per mille , suggesting that M. sinensis (a C4 plant) contributed to carbon storage, whereas there was little carbon accumulation from P. densiflora (a C3 plant) in forest soil. The Δ 14 C values and calculated soil carbon mean residence time (MRT) showed that the soil carbon in the upper A horizon was older, and that in the lower A horizon was younger in forest than in grassland. From these results, we conclude that young, fast-MRT soil carbon is decomposed in the upper A horizon, and old, stable soil carbon was decomposed in the lower A horizon after the pine invasion.

  7. Changes in productivity of grassland with ageing

    NARCIS (Netherlands)

    Hoogerkamp, M.

    1984-01-01

    The productivity of grassland may change greatly with ageing. Frequently, a productive ley period, occurring in the first time after (re)seeding, is followed by a period in which productivity decreases. Under conditions favourable to grassland this may be temporary. A production level

  8. Energy production from grassland - Assessing the sustainability of different process chains under German conditions

    International Nuclear Information System (INIS)

    Roesch, Christine; Skarka, J.; Raab, K.; Stelzer, V.

    2009-01-01

    In many regions of Europe, grassland shapes the landscape and fulfils important functions in protecting nature, soil, and water. However, the traditional uses of grassland for forage production are vanishing with progress in breeding and structural adaptations in agriculture. On the other hand, the demand for biomass energy is rising due to political sustainability goals and financial measures to support renewable energy. Against this background, the Institute for Technology Assessment and Systems Analysis investigated the applicability, economic efficiency, and sustainability of different techniques for energy production from grassland as well as from grassland converted into maize fields or short-rotation poplars under German conditions. The results show that despite relatively high energy prices and the financial support for bioenergy, the effects of energy production from grassland on employment in agriculture and farmers' income are modest. What is beneficial are savings in non-renewable energy, reductions in greenhouse gas emissions, and local provision of energy carriers. If grassland biomass (grass silage or hay) is used for energy purposes, this brings the further advantages of preserving biodiversity and the cultural landscape and protecting of soil and groundwater. Negative impacts on sustainable development result from an increase in emissions, which leads to acidification, eutrophication, and risks to human health. The overall evaluation indicates that short-rotation poplars are comparatively advantageous from the economic and ecological point of view. Therefore, a development plan for grassland is required to identify areas where grassland could be used as an energy resource or where it would be favourable to install energy plantations with fast-growing perennial plants

  9. Botanical identification of plants described in Mādhava Cikitsā for the treatment of diarrhoea.

    Science.gov (United States)

    Salve, Niteen Ramdas; Mishra, Debendranath

    2016-01-01

    Mādhava is regarded as a 7(th) century Indian Physician who composed two treatises (in Sanskrit) on Ayurveda, the Mādhava Nidāna and Mādhava Cikitsā. The former treatise deals with the diagnosis of diseases while the latter with the treatment using medicinal plants and other recipes. In Mādhava Cikitsā, a common Sanskrit name is found to describe two or more totally different botanical plant species (thus leading to ambiguity) and a distinct botanical species is also found to represent two or more Sanskrit names at several instances. The present paper deals with the correct botanical identification (most probable) of Sanskrit named plants described in Mādhava Cikitsā for the treatment of Diarrhoea (Atisāra Cikitsā). The authentic manuscripts of 'Mādhava Cikitsā' were critically studied for the present research outcome. A detailed literature survey is carried out from various references and texts. The list of Sanskrit named plants contains 103 names, while after the critical study and assigning the most probable botanical identification as per ICBN, the list of plant species described in the text for the treatment of Diarrhoea is found to contain 73 names. The present study will certainly benefit Ayurvedic medical practitioners and pharmaceutical companies in selection of proper plant species avoiding substitutions for drug formulation.

  10. Enrichment culture and identification of endophytic methanotrophs isolated from peatland plants.

    Science.gov (United States)

    Stępniewska, Zofia; Goraj, Weronika; Kuźniar, Agnieszka; Łopacka, Natalia; Małysza, Magdalena

    2017-09-01

    Aerobic methane-oxidizing bacteria (MOB) are an environmentally significant group of microorganisms due to their role in the global carbon cycle. Research conducted over the past few decades has increased the interest in discovering novel genera of methane-degrading bacteria, which efficiently utilize methane and decrease the global warming effect. Moreover, methanotrophs have more promising applications in environmental bioengineering, biotechnology, and pharmacy. The investigations were undertaken to recognize the variety of endophytic methanotrophic bacteria associated with Carex nigra, Vaccinium oxycoccus, and Eriophorum vaginatum originating from Moszne peatland (East Poland). Methanotrophic bacteria were isolated from plants by adding sterile fragments of different parts of plants (roots and stems) to agar mineral medium (nitrate mineral salts (NMS)) and incubated at different methane values (1-20% CH4). Single colonies were streaked on new NMS agar media and, after incubation, transferred to liquid NMS medium. Bacterial growth dynamics in the culture solution was studied by optical density-OD600 and methane consumption. Changes in the methane concentration during incubation were controlled by the gas chromatography technique. Characterization of methanotrophs was made by fluorescence in situ hybridization (FISH) with Mg705 and Mg84 for type I methanotrophs and Ma450 for type II methanotrophs. Identification of endophytes was performed after 16S ribosomal RNA (rRNA) and mmoX gene amplification. Our study confirmed the presence of both types of methanotrophic bacteria (types I and II) with the predominance of type I methanotrophs. Among cultivable methanotrophs, there were different strains of the genus Methylomonas and Methylosinus. Furthermore, we determined the potential of the examined bacteria for methane oxidation, which ranged from 0.463 ± 0.067 to 5.928 ± 0.169 μmol/L CH4/mL/day.

  11. Molecular Identification Of Trichoderma Strains Collected To Develop Plant Growth-Promoting And Biocontrol Agents

    Directory of Open Access Journals (Sweden)

    Oskiera Michał

    2015-06-01

    Full Text Available Trichoderma strains that are beneficial to both the growth and health of plants can be used as plant growth-promoting fungi (PGPF or biological control agents (BCA in agricultural and horticultural practices. In order to select PGPF or BCA strains, their biological properties and taxonomy must be carefully studied. In this study, 104 strains of Trichoderma collected at geographically different locations in Poland for selection as PGPF or BCA were identified by DNA barcoding, based on the sequences of internal transcribed spacers 1 and 2 (ITS1 and 2 of the ribosomal RNA gene cluster and on the sequences of translation elongation factor 1 alpha (tef1, chitinase 18-5 (chi18-5, and RNA polymerase II subunit (rpb2 gene fragments. Most of the strains were classified as: T. atroviride (38%, T. harzianum (21%, T. lentiforme (9%, T. virens (9%, and T. simmonsii (6%. Single strains belonging to T. atrobrunneum, T. citrinoviride, T. crassum, T. gamsii, T. hamatum, T. spirale, T. tomentosum, and T. viridescens were identified. Three strains that are potentially pathogenic to cultivated mushrooms belonging to T. pleuroticola and T. aggressivum f. europaeum were also identified. Four strains: TRS4, TRS29, TRS33, and TRS73 were classified to Trichoderma spp. and molecular identification was inconclusive at the species level. Phylogeny analysis showed that three of these strains TRS4, TRS29, and TRS33 belong to Trichoderma species that is not yet taxonomically established and strain TRS73 belongs to the T. harzianum complex, however, the species could not be identified with certainty.

  12. Effects of forest expansion on mountain grassland

    DEFF Research Database (Denmark)

    Guidi, Claudia; Magid, Jakob; Rodeghiero, Mirco

    2014-01-01

    Background and aims. Grassland abandonment followed by forest succession is the dominant land-use change in the European Alps. We studied the impact of current forest expansion on mountain grassland on changes in physical soil organic carbon (SOC) fractions along a land-use and management gradient......, focusing on changes in aggregate stability and particulate organic matter (POM). Methods. Four successional stages were investigated: managed grassland, two transitional phases in which grassland abandonment led to colonization by Picea abies (L.) Karst., and old mixed forest dominated by Fagus sylvatica L....... Results. The dimension of aggregates assessed by aggregate size fractionation tended to increase, whereas SOC allocation to stable aggregates assessed by sizedensity fractionation decreased following conversion of grassland to forest (e.g. from 81 to 59 % in the 0–5 cm layer). The amount of SOC stored...

  13. In-Born Radio Frequency Identification Devices for Safeguards Use at Gas-Centrifuge Enrichment Plants

    International Nuclear Information System (INIS)

    Ward, R.; Rosenthal, M.

    2009-01-01

    Global expansion of nuclear power has made the need for improved safeguards measures at Gas Centrifuge Enrichment Plants (GCEPs) imperative. One technology under consideration for safeguards applications is Radio Frequency Identification Devices (RFIDs). RFIDs have the potential to increase IAEA inspector's efficiency and effectiveness either by reducing the number of inspection visits necessary or by reducing inspection effort at those visits. This study assesses the use of RFIDs as an integral component of the 'Option 4' safeguards approach developed by Bruce Moran, U.S. Nuclear Regulatory Commission (NRC), for a model GCEP [1]. A previous analysis of RFIDs was conducted by Jae Jo, Brookhaven National Laboratory (BNL), which evaluated the effectiveness of an RFID tag applied by the facility operator [2]. This paper presents a similar evaluation carried out in the framework of Jo's paper, but it is predicated on the assumption that the RFID tag is applied by the manufacturer at the birth of the cylinder, rather than by the operator. Relevant diversion scenarios are examined to determine if RFIDs increase the effectiveness and/ or efficiency of safeguards in these scenarios. Conclusions on the benefits offered to inspectors by using in-born RFID tagging are presented.

  14. Identification of potential safety-related incidents applicable to a breeder fuel reprocessing plant

    International Nuclear Information System (INIS)

    Perkins, W.C.

    1980-01-01

    The current emphasis on safety in all phases of the nuclear fuel cycle requires that safety features be identified and included in designs of nuclear facilities at the earliest possible stage. A popular method for the early identification of these safety features is the Preliminary Hazards Analysis. An extension of this analysis is to illustrate the nature of a hazard by its effects in accident situations, that is, to identify what are called safety-related incidents. Some useful tools are described which have been used at the Savannah River Laboratory, SRL, to make Preliminary Hazards Analyses as well as safety analyses of facilities for processing spent nuclear fuels from both power and production reactors. These tools have also been used in safety studies of waste handling operations at the Savannah River Plant. The tools are the SRL Incidents Data Bank and the What If meeting. The application of this methodology to a proposed facility which has breeder fuel reprocessing capability, the Hot Experimental Facility (HEF) is illustrated

  15. Species-specific identification from incomplete sampling: applying DNA barcodes to monitoring invasive solanum plants.

    Science.gov (United States)

    Zhang, Wei; Fan, Xiaohong; Zhu, Shuifang; Zhao, Hong; Fu, Lianzhong

    2013-01-01

    Comprehensive sampling is crucial to DNA barcoding, but it is rarely performed because materials are usually unavailable. In practice, only a few rather than all species of a genus are required to be identified. Thus identification of a given species using a limited sample is of great importance in current application of DNA barcodes. Here, we selected 70 individuals representing 48 species from each major lineage of Solanum, one of the most species-rich genera of seed plants, to explore whether DNA barcodes can provide reliable specific-species discrimination in the context of incomplete sampling. Chloroplast genes ndhF and trnS-trnG and the nuclear gene waxy, the commonly used markers in Solanum phylogeny, were selected as the supplementary barcodes. The tree-building and modified barcode gap methods were employed to assess species resolution. The results showed that four Solanum species of quarantine concern could be successfully identified through the two-step barcoding sampling strategy. In addition, discrepancies between nuclear and cpDNA barcodes in some samples demonstrated the ability to discriminate hybrid species, and highlights the necessity of using barcode regions with different modes of inheritance. We conclude that efficient phylogenetic markers are good candidates as the supplementary barcodes in a given taxonomic group. Critically, we hypothesized that a specific-species could be identified from a phylogenetic framework using incomplete sampling-through this, DNA barcoding will greatly benefit the current fields of its application.

  16. The Rocky Flats Plant Waste Stream and Residue Identification and Characterization Program (WSRIC): Progress and achievements

    International Nuclear Information System (INIS)

    Ideker, V.L.

    1994-01-01

    The Waste Stream and Residue Identification and Characterization (WSRIC) Program, as described in the WSRIC Program Description delineates the process knowledge used to identify and characterize currently-generated waste from approximately 5404 waste streams originating from 576 processes in 288 buildings at Rocky Flats Plant (RFP). Annual updates to the WSRIC documents are required by the Federal Facilities Compliance Agreement between the US Department of Energy, the Colorado Department of Health and the Environmental Protection Agency. Accurate determination and characterization of waste is a crucial component in RFP's waste management strategy to assure compliance with Resource Conservation and Recovery Act (RCRA) storage and treatment requirements, as well as disposal acceptance criteria. The WSRIC Program was rebaselined in September 1992, and serves as the linchpin for documenting process knowledge in RFP's RCRA operating record. Enhancements to the WSRIC include strengthening the waste characterization rationale, expanding WSRIC training for waste generators, and incorporating analytical information into the WSRIC building books. These enhancements will improve credibility with the regulators and increase waste generators' understanding of the basis for credible waste characterizations

  17. Identification of plant configurations maximizing radiation capture in relay strip cotton using a functional-structural plant model

    NARCIS (Netherlands)

    Mao, Lili; Zhang, Lizhen; Evers, J.B.; Henke, M.; Werf, van der W.; Liu, Shaodong; Zhang, Siping; Zhao, Xinhua; Wang, Baomin; Li, Zhaohu

    2016-01-01

    One of the key decisions in crop production is the choice of row distance and plant density. The choice of these planting pattern parameters is especially challenging in heterogeneous systems, such as systems containing alternating strips. Here we use functional-structural plant modelling to

  18. Hierarchical traits distances explain grassland Fabaceae species' ecological niches distances

    Science.gov (United States)

    Fort, Florian; Jouany, Claire; Cruz, Pablo

    2015-01-01

    Fabaceae species play a key role in ecosystem functioning through their capacity to fix atmospheric nitrogen via their symbiosis with Rhizobium bacteria. To increase benefits of using Fabaceae in agricultural systems, it is necessary to find ways to evaluate species or genotypes having potential adaptations to sub-optimal growth conditions. We evaluated the relevance of phylogenetic distance, absolute trait distance and hierarchical trait distance for comparing the adaptation of 13 grassland Fabaceae species to different habitats, i.e., ecological niches. We measured a wide range of functional traits (root traits, leaf traits, and whole plant traits) in these species. Species phylogenetic and ecological distances were assessed from a species-level phylogenetic tree and species' ecological indicator values, respectively. We demonstrated that differences in ecological niches between grassland Fabaceae species were related more to their hierarchical trait distances than to their phylogenetic distances. We showed that grassland Fabaceae functional traits tend to converge among species with the same ecological requirements. Species with acquisitive root strategies (thin roots, shallow root systems) are competitive species adapted to non-stressful meadows, while conservative ones (coarse roots, deep root systems) are able to tolerate stressful continental climates. In contrast, acquisitive species appeared to be able to tolerate low soil-P availability, while conservative ones need high P availability. Finally we highlight that traits converge along the ecological gradient, providing the assumption that species with similar root-trait values are better able to coexist, regardless of their phylogenetic distance. PMID:25741353

  19. Hierarchical traits distances explain grassland Fabaceae species’ ecological niches distances

    Directory of Open Access Journals (Sweden)

    Florian eFort

    2015-02-01

    Full Text Available Fabaceae species play a key role in ecosystem functioning through their capacity to fix atmospheric nitrogen via their symbiosis with Rhizobium bacteria. To increase benefits of using Fabaceae in agricultural systems, it is necessary to find ways to evaluate species or genotypes having potential adaptations to sub-optimal growth conditions. We evaluated the relevance of phylogenetic distance, absolute trait distance and hierarchical trait distance for comparing the adaptation of 13 grassland Fabaceae species to different habitats, i.e. ecological niches. We measured a wide range of functional traits (root traits, leaf traits and whole plant traits in these species. Species phylogenetic and ecological distances were assessed from a species-level phylogenetic tree and species’ ecological indicator values, respectively. We demonstrated that differences in ecological niches between grassland Fabaceae species were related more to their hierarchical trait distances than to their phylogenetic distances. We showed that grassland Fabaceae functional traits tend to converge among species with the same ecological requirements. Species with acquisitive root strategies (thin roots, shallow root systems are competitive species adapted to non-stressful meadows, while conservative ones (coarse roots, deep root systems are able to tolerate stressful continental climates. In contrast, acquisitive species appeared to be able to tolerate low soil-P availability, while conservative ones need high P availability. Finally we highlight that traits converge along the ecological gradient, providing the assumption that species with similar root-trait values are better able to coexist, regardless of their phylogenetic distance.

  20. Variability of annual CO2 exchange from Dutch grasslands

    NARCIS (Netherlands)

    Jacobs, C.M.J.; Jacobs, A.F.G.; Bosveld, F.C.; Hendriks, D.M.D.; Hensen, A.; Kroon, P.; Moors, E.J.; Nol, L.; Schrier-Uijl, A.P.; Veenendaal, E.M.

    2007-01-01

    An intercomparison is made of the Net Ecosystem Exchange of CO2, NEE, for eight Dutch grassland sites: four natural grasslands, two production grasslands and two meteorological stations within a rotational grassland region. At all sites the NEE was determined during at least 10 months per site,

  1. Land-use intensification causes multitrophic homogenization of grassland communities.

    Science.gov (United States)

    Gossner, Martin M; Lewinsohn, Thomas M; Kahl, Tiemo; Grassein, Fabrice; Boch, Steffen; Prati, Daniel; Birkhofer, Klaus; Renner, Swen C; Sikorski, Johannes; Wubet, Tesfaye; Arndt, Hartmut; Baumgartner, Vanessa; Blaser, Stefan; Blüthgen, Nico; Börschig, Carmen; Buscot, Francois; Diekötter, Tim; Jorge, Leonardo Ré; Jung, Kirsten; Keyel, Alexander C; Klein, Alexandra-Maria; Klemmer, Sandra; Krauss, Jochen; Lange, Markus; Müller, Jörg; Overmann, Jörg; Pašalić, Esther; Penone, Caterina; Perović, David J; Purschke, Oliver; Schall, Peter; Socher, Stephanie A; Sonnemann, Ilja; Tschapka, Marco; Tscharntke, Teja; Türke, Manfred; Venter, Paul Christiaan; Weiner, Christiane N; Werner, Michael; Wolters, Volkmar; Wurst, Susanne; Westphal, Catrin; Fischer, Markus; Weisser, Wolfgang W; Allan, Eric

    2016-12-08

    Land-use intensification is a major driver of biodiversity loss. Alongside reductions in local species diversity, biotic homogenization at larger spatial scales is of great concern for conservation. Biotic homogenization means a decrease in β-diversity (the compositional dissimilarity between sites). Most studies have investigated losses in local (α)-diversity and neglected biodiversity loss at larger spatial scales. Studies addressing β-diversity have focused on single or a few organism groups (for example, ref. 4), and it is thus unknown whether land-use intensification homogenizes communities at different trophic levels, above- and belowground. Here we show that even moderate increases in local land-use intensity (LUI) cause biotic homogenization across microbial, plant and animal groups, both above- and belowground, and that this is largely independent of changes in α-diversity. We analysed a unique grassland biodiversity dataset, with abundances of more than 4,000 species belonging to 12 trophic groups. LUI, and, in particular, high mowing intensity, had consistent effects on β-diversity across groups, causing a homogenization of soil microbial, fungal pathogen, plant and arthropod communities. These effects were nonlinear and the strongest declines in β-diversity occurred in the transition from extensively managed to intermediate intensity grassland. LUI tended to reduce local α-diversity in aboveground groups, whereas the α-diversity increased in belowground groups. Correlations between the β-diversity of different groups, particularly between plants and their consumers, became weaker at high LUI. This suggests a loss of specialist species and is further evidence for biotic homogenization. The consistently negative effects of LUI on landscape-scale biodiversity underscore the high value of extensively managed grasslands for conserving multitrophic biodiversity and ecosystem service provision. Indeed, biotic homogenization rather than local diversity

  2. [Effects of desertification on C and N storages in grassland ecosystem on Horqin sandy land].

    Science.gov (United States)

    Zhao, Ha-lin; Li, Yu-qiang; Zhou, Rui-lian

    2007-11-01

    Sandy grassland is widespread in northern China, where desertification is very common because of overgrazing and estrepement. However, little is known about the effects of desertification on grassland C and N storages in this region. A field survey was conducted on Horqin sandy grassland, and desertification gradients were established to evaluate the effects of desertification on C and N storages in soil, plant, and litter. The results showed that desertification had deep effects on the contents and storages of grassland C and N. The C and N contents and storages in the grassland decreased significantly with increasing desertification degree. Comparing with those in un-desertified grassland, the C and N contents in lightly, moderately, heavily, and severely desertified grasslands decreased by 56.06% and 48.72%, 78.43% and 74.36%, 88.95% and 84.62%, and 91.64% and 84.62% in 0-100 cm soil layer, and by 8.61% and 6.43%, 0.05% and 25.71%, 2.58% and 27.14%, and 8. 61% and 27. 86% in plant components, respectively. Relevantly, the C and N storages decreased by 50.95% and 43.38%, 75.19% and 71.04%, 86.76% and 81.48%, and 91.17% and 83.17% in plant underground components in 0-100 cm soil layer, and by 25.08% and 27.62%, 30.90% and 46.55%, 73.84% and 80.62%, and 90.89% and 87.31% in plant aboveground components, respectively. In 2000, the total area of desertified grassland in Horqin sandy land was 30152. 7 km2, and the C and N loss via desertification reached up to 107.53 and 9.97 Mt, respectively. Correlation analysis indicated that the decrease of soil C and N contents was mainly come from the decreased soil fine particles caused by wind erosion in the process of desertification, and the degradation of soil texture- and nutrient status led finally to the rapid decrease of C and N storages in plant biomass and litter.

  3. Identification of medicinal plants in the family Fabaceae using a potential DNA barcode ITS2.

    Science.gov (United States)

    Gao, Ting; Yao, Hui; Song, Jingyuan; Liu, Chang; Zhu, Yingjie; Ma, Xinye; Pang, Xiaohui; Xu, Hongxi; Chen, Shilin

    2010-07-06

    To test whether the ITS2 region is an effective marker for use in authenticating of the family Fabaceae which contains many important medicinal plants. The ITS2 regions of 114 samples in Fabaceae were amplified. Sequence assembly was assembled by CodonCode Aligner V3.0. In combination with sequences from public database, the sequences were aligned by Clustal W, and genetic distances were computed using MEGA V4.0. The intra- vs. inter-specific variations were assessed by six metrics, wilcoxon two-sample tests and "barcoding gaps". Species identification was accomplished using TaxonGAP V2.4, BLAST1 and the nearest distance method. ITS2 sequences had considerable variation at the genus and species level. The intra-specific divergence ranged from 0% to 14.4%, with an average of 1.7%, and the inter-specific divergence ranged from 0% to 63.0%, with an average of 8.6%. Twenty-four species found in the Chinese Pharmacopoeia, along with another 66 species including their adulterants, were successfully identified based on ITS2 sequences. In addition, ITS2 worked well, with over 80.0% of species and 100% of genera being correctly differentiated for the 1507 sequences derived from 1126 species belonging to 196 genera. Our findings support the notion that ITS2 can be used as an efficient and powerful marker and a potential barcode to distinguish various species in Fabaceae. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

  4. Identification of HMG-CoA Reductase Inhibitor Active Compound in Medicinal Forest Plants

    Directory of Open Access Journals (Sweden)

    Shelly Rahmania

    2017-08-01

    Full Text Available Cardiovascular disease is a leading cause of death worldwide, hypercholesterolemia is one of the causes. Three medicinal forest plants are potential natural resources to be developed as cholesterol-reducing herbal product, but scientific informations on their mechanism is still limited. The objective of this research is to explore the potency of the leaf of Jati Belanda (Guazuma ulmifolia, Jabon (Antocephalus macrophyllus, and Mindi (Melia azedarach as inhibitor of HMG-CoA reductase (HMGR, a key enzyme in the regulation of cholesterol biosynthesis. Samples were macerated in ethanol 96% and the filtrate was partitioned using n-hexane and chloroform to obtain the ethanolic flavonoid extract. The effect of each extracts on the HMG-CoA reductase activity were analyzed using HMGR assay kit. At concentration of 10 ppm the G.ulmifolia ethanolic extract showed the highest inhibitory activity as well as pravastatin control inhibitor.  The phenolic content of the ethanolic extracts of G.ulmifolia, A.macrophyllus, and M.azedarach were: 11.00, 34.83, and 13.67 mg gallic acid AE/g dried leaves, respectively. The flavonoid content of the ethanolic extracts of G.ulmifolia, A.macrophyllus, and M.azedarach were: 0.22, 0.64, and 0.78 mg QE/g dried leaves, respectively. Interestingly, G.ulmifolia extract the lowest concentration of phenolic and flavonoid content. HPLC analysis showed that all samples contain quercetin at similiar small concentrations (6.7%, 6.6%, and 7.0% for G.ulmifolia, A.macrophyllus, and M.azedarach, respectively. This indicating other active compounds may play some roles in this inhibitory action on HMG-CoA reductase activity. Further identification using LC-MS/MS showed that G.ulmifolia flavonoid extract contained an unidetified coumpound with molecural weight of 380.0723 Da.  

  5. LEAF AREA DYNAMICS AND ABOVEGROUND BIOMASS OF SPECIFIC VEGETATION TYPES OF A SEMI-ARID GRASSLAND IN SOUTHERN ETHIOPIA

    Directory of Open Access Journals (Sweden)

    Bosco Kidake Kisambo

    2016-12-01

    Full Text Available Leaf Area Index (LAI dynamics and aboveground biomass of a semi-arid grassland region in Southern Ethiopia were determined over a long rain season. The vegetation was categorized into four distinct vegetation types namely Grassland (G, Tree-Grassland (TG, Bushed-Grassland (BG and Bush-Tree grassland (BT. LAI was measured using a Plant Canopy Analyzer (LAI2000. Biomass dynamics of litter and herbaceous components were determined through clipping while the above ground biomass of trees and shrubs were estimated using species-specific allometric equations from literature. LAI showed a seasonal increase over the season with the maximum recorded in the BG vegetation (2.52. Total aboveground biomass for the different vegetation types ranged from 0.61 ton C/ha in areas where trees were non-existent to 8.80 ± 3.81ton C/ha in the Tree-Grassland vegetation in the study site. A correlation of LAI and AGB yielded a positive relationship with an R2 value of 0.55. The results demonstrate the importance of tropical semi-arid grasslands as carbon sinks hence their potential in mitigation of climate change.

  6. Towards Plant Species Identification in Complex Samples: A Bioinformatics Pipeline for the Identification of Novel Nuclear Barcode Candidates.

    Directory of Open Access Journals (Sweden)

    Alexandre Angers-Loustau

    Full Text Available Monitoring of the food chain to fight fraud and protect consumer health relies on the availability of methods to correctly identify the species present in samples, for which DNA barcoding is a promising candidate. The nuclear genome is a rich potential source of barcode targets, but has been relatively unexploited until now. Here, we show the development and use of a bioinformatics pipeline that processes available genome sequences to automatically screen large numbers of input candidates, identifies novel nuclear barcode targets and designs associated primer pairs, according to a specific set of requirements. We applied this pipeline to identify novel barcodes for plant species, a kingdom for which the currently available solutions are known to be insufficient. We tested one of the identified primer pairs and show its capability to correctly identify the plant species in simple and complex samples, validating the output of our approach.

  7. Actin gene identification from selected medicinal plants for their use as internal controls for gene expression studies

    International Nuclear Information System (INIS)

    Mufti, F.U.D.; Banaras, S.

    2015-01-01

    Internal control genes are the constitutive genes which maintain the basic cellular functions and regularly express in both normal and stressed conditions in living organisms. They are used in normalization of gene expression studies in comparative analysis of target genes, as their expression remains comparatively unchanged in all varied conditions. Among internal control genes, actin is considered as a candidate gene for expression studies due to its vital role in shaping cytoskeleton and plant physiology. Unfortunately most of such knowledge is limited to only model plants or crops, not much is known about important medicinal plants. Therefore, we selected seven important medicinal wild plants for molecular identification of actin gene. We used gene specific primers designed from the conserved regions of several known orthologues or homologues of actin genes from other plants. The amplified products of 370-380 bp were sequenced and submitted to GeneBank after their confirmation using different bioinformatics tools. All the novel partial sequences of putative actin genes were submitted to GeneBank (Parthenium hysterophorus (KJ774023), Fagonia indica (KJ774024), Rhazya stricta (KJ774025), Whithania coagulans (KJ774026), Capparis decidua (KJ774027), Verbena officinalis (KJ774028) and Aerva javanica (KJ774029)). The comparisons of these partial sequences by Basic Local Alignment Search Tool (BLAST) and phylogenetic trees demonstrated high similarity with known actin genes of other plants. Our findings illustrated highly conserved nature of actin gene among these selected plants. These novel partial fragments of actin genes from these wild medicinal plants can be used as internal controls for future gene expression studies of these important plants after precise validations of their stable expression in such plants. (author)

  8. Biology and ecology of sickleweed (Falcaria vulgaris) in the Fort Pierre National Grassland of South Dakota

    Science.gov (United States)

    Brian L. Korman

    2011-01-01

    In the last two decades the exotic plant sickleweed (Falcaria vulgaris Bernh., Apiaceae) has invaded, and come to dominate, large areas of the Fort Pierre National Grassland (FPNG) in central South Dakota, USA. Currently sickleweed is estimated to infest over 3200 ha of FPNG. The purpose of this study was to examine several of the biological and ecological traits that...

  9. Simple models to predict grassland ecosystem C exchange and actual evapotranspiration using NDVI and environmental variables

    Science.gov (United States)

    Semiarid grasslands contribute significantly to net terrestrial carbon flux as plant productivity and heterotrophic respiration in these moisture-limited systems are correlated with metrics related to water availability (e.g., precipitation, Actual EvapoTranspiration or AET). These variables are als...

  10. Dependence of the conservation status of acid grasslands at the Pohorje and Kozjak on socioeconomic parameters

    Directory of Open Access Journals (Sweden)

    Karmen KETIŠ

    2015-12-01

    Full Text Available Grassland habitats were studied on twenty farms on the area of the Radlje ob Dravi administration unit, in the transect from Kozjak to Pohorje at different altitudes. The aim of the study was to investigate how environmental and  socio-economic parameters influence the diversity of plant species and, consequently, the conservation of grassland on acid soils, which are rare in Slovenia and are therefore more protected. The socioeconomic structure of farms was studied on the basis of an inquiry carried out on farms. Part-time farms prevail; the average age of farmers is 56.5 years, and 30% of farmers has no education or just elementary school. The relationship among the environmental, socio-economic parameters and floristic structures of grasslands was studied using canonic-correspondence analysis. The impact of 16 parameters was analysed, of which six were determined not to be statistically significant. The occurrence of chosen plant species was analysed in relation to environmental and socioeconomic parameters. The efficiency of agro-environmental subsidies in relation to plant species diversity was evaluated. It was determined that the education and age of farmers influence the intensity of farming and consequently have an impact on the diversity of plants species and the conservation status of grasslands.

  11. A prototype application of state and transition simulation modeling in support of grassland management

    Science.gov (United States)

    Matt Reeves; Paulette Ford; Leonardo Frid; David Augustine; Justin Derner

    2016-01-01

    The Great Plains grasslands of North America provide a multitude of ecosystem services including clean water, forage, habitat, recreation, and pollination of native and agricultural plants. A general lack of quantitative information regarding the effects of varied management strategies on these spatially heterogeneous landscapes complicates our understanding...

  12. High potential of sub-Mediterranean dry grasslands for sheep epizoochory

    Directory of Open Access Journals (Sweden)

    Kaligarič Mitja

    2016-01-01

    Full Text Available There is a general decline of grasslands across Europe due to habitat loss and degradation. Ensuring plant dispersal thus becomes a key process for preserving grassland patches in all scales. We examined diaspore dispersal by sheep epizoochory in the pastures of the North Adriatic Karst (NW Slovenia and determined the qualitative and quantitative features of diaspores in fur. We recorded 25,650 diaspores of 141 plant taxa (with 107 taxa and 23,350 diaspores determined to species level, using three different methods: (i the “whole-coat method”, (ii the “part-of-thecoat method” and (iii a “seedling emergence method”. A comparison of these techniques revealed that the “wholecoat method” provided the highest number of diaspores and plant species. All diaspores were clustered into five emergent groups based on seven functional traits (diaspore weight, length, width, height, volume, specific weight and the diaspore surface structure. Our research revealed that sheep represent an important dispersal vector, since about half of the plant species recorded in the pastures were found as diaspores in fur. This study contributes to knowledge about the modes of seed dispersal in seminatural grasslands. Taking into account that livestock play a key role in vegetation dynamics, understanding their effects on seed dispersal is essential for conservation and restoration of these species-rich grassland communities.

  13. Grassland invader responses to realistic changes in native species richness.

    Science.gov (United States)

    Rinella, Matthew J; Pokorny, Monica L; Rekaya, Romdhane

    2007-09-01

    The importance of species richness for repelling exotic plant invasions varies from ecosystem to ecosystem. Thus, in order to prioritize conservation objectives, it is critical to identify those ecosystems where decreasing richness will most greatly magnify invasion risks. Our goal was to determine if invasion risks greatly increase in response to common reductions in grassland species richness. We imposed treatments that mimic management-induced reductions in grassland species richness (i.e., removal of shallow- and/or deep-rooted forbs and/or grasses and/or cryptogam layers). Then we introduced and monitored the performance of a notorious invasive species (i.e., Centaurea maculosa). We found that, on a per-gram-of-biomass basis, each resident plant group similarly suppressed invader growth. Hence, with respect to preventing C. maculosa invasions, maintaining overall productivity is probably more important than maintaining the productivity of particular plant groups or species. But at the sites we studied, all plant groups may be needed to maintain overall productivity because removing forbs decreased overall productivity in two of three years. Alternatively, removing forbs increased productivity in another year, and this led us to posit that removing forbs may inflate the temporal productivity variance as opposed to greatly affecting time-averaged productivity. In either case, overall productivity responses to single plant group removals were inconsistent and fairly modest, and only when all plant groups were removed did C. maculosa growth increase substantially over a no-removal treatment. As such, it seems that intense disturbances (e.g., prolonged drought, overgrazing) that deplete multiple plant groups may often be a prerequisite for C. maculosa invasion.

  14. A review of phenolic compounds in oil-bearing plants: Distribution, identification and occurrence of phenolic compounds.

    Science.gov (United States)

    Alu'datt, Muhammad H; Rababah, Taha; Alhamad, Mohammad N; Al-Mahasneh, Majdi A; Almajwal, Ali; Gammoh, Sana; Ereifej, Khalil; Johargy, Ayman; Alli, Inteaz

    2017-03-01

    Over the last two decades, separation, identification and measurement of the total and individual content of phenolic compounds has been widely investigated. Recently, the presence of a wide range of phenolic compounds in oil-bearing plants has been shown to contribute to their therapeutic properties, including anti-cancer, anti-viral, anti-oxidant, hypoglycemic, hypo-lipidemic, and anti-inflammatory activities. Phenolics in oil-bearing plants are now recognized as important minor food components due to several organoleptic and health properties, and they are used as food or sources of food ingredients. Variations in the content of phenolics in oil-bearing plants have largely been attributed to several factors, including the cultivation, time of harvest and soil types. A number of authors have suggested that the presence phenolics in extracted proteins, carbohydrates and oils may contribute to objectionable off flavors The objective of this study was to review the distribution, identification and occurrence of free and bound phenolic compounds in oil-bearing plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Description of the Grassland Biome Project

    CSIR Research Space (South Africa)

    Mentis, MT

    1982-10-01

    Full Text Available The objectives, organization and research programme of the Grassland Biome Project are described against a background of the biome's ecological characteristics and environmental problems. Four principal research topics wil 1 be focused upon: (i...

  16. Asymmetric responses of primary productivity to precipitation extremes: A synthesis of grassland precipitation manipulation experiments

    Czech Academy of Sciences Publication Activity Database

    Wilcox, K. R.; Shi, Z.; Gherardi, L. A.; Lemoine, N. P.; Koerner, S. E.; Hoover, D. L.; Bork, E.; Byrne, K. M.; Cahill, J.; Collins, S. L.; Evans, S.M.; Gilgen, Anna K.; Holub, Petr; Jiang, L.; Knapp, A. K.; LeCain, D.; Liang, J.; Garcia-Palacios, P.; Penuelas, J.; Pockman, W. T.; Smith, M. D.; Sun, S.; White, S. R.; Yahdjian, L.; Zhu, K.; Luo, Y.

    2017-01-01

    Roč. 23, č. 10 (2017), s. 4376-4385 ISSN 1354-1013 Institutional support: RVO:86652079 Keywords : net primary productivity * terrestrial ecosystems * temperate grassland * biomass allocation * plant-communities * tallgrass prairie * climate extremes * use efficiency * united-states * global-change * aboveground net primary productivity * belowground net primary productivity * biomass allocation * climate change * grasslands * meta-analysis * root biomass Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 8.502, year: 2016

  17. The Identification of Genes Important in Pseudomonas syringae pv. phaseolicola Plant Colonisation Using In Vitro Screening of Transposon Libraries.

    Directory of Open Access Journals (Sweden)

    Bharani Manoharan

    Full Text Available The bacterial plant pathogen Pseudomonas syringae pv. phaseolicola (Pph colonises the surface of common bean plants before moving into the interior of plant tissue, via wounds and stomata. In the intercellular spaces the pathogen proliferates in the apoplastic fluid and forms microcolonies (biofilms around plant cells. If the pathogen can suppress the plant's natural resistance response, it will cause halo blight disease. The process of resistance suppression is fairly well understood, but the mechanisms used by the pathogen in colonisation are less clear. We hypothesised that we could apply in vitro genetic screens to look for changes in motility, colony formation, and adhesion, which are proxies for infection, microcolony formation and cell adhesion. We made transposon (Tn mutant libraries of Pph strains 1448A and 1302A and found 106/1920 mutants exhibited alterations in colony morphology, motility and biofilm formation. Identification of the insertion point of the Tn identified within the genome highlighted, as expected, a number of altered motility mutants bearing mutations in genes encoding various parts of the flagellum. Genes involved in nutrient biosynthesis, membrane associated proteins, and a number of conserved hypothetical protein (CHP genes were also identified. A mutation of one CHP gene caused a positive increase in in planta bacterial growth. This rapid and inexpensive screening method allows the discovery of genes important for in vitro traits that can be correlated to roles in the plant interaction.

  18. Evaluation of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) for N2O mitigation after grassland cultivation

    DEFF Research Database (Denmark)

    Kong, Xianwang

    Temporary grasslands cover ca. 11 million ha and constitute more than 10% of the total arable land within EU-28; in Denmark, ca. 60% of the grasslands are included in crop rotations. The high productivity and the positive residual effect on succeeding crops are the main reasons of placing...... archaea (AOA), as revealed by mRNA transcripts of amoA gene. This inhibitory effect could be limited to the soil volume in close contact with residues, where residue decomposition and subsequent nitrification took place. In the field study, there was a trend towards lower biomass yield and N...... grasslands in crop rotations. At the transition phase, the mineralization of grass and clover residues incorporated by grassland cultivation can supply nitrogen to a succeeding crop; however, the plant N-uptake is low for several weeks at the early growth stage. During this period, as a result of increasing...

  19. Grassland communities in the USA and expected trends associated with climate change

    Directory of Open Access Journals (Sweden)

    David Paul Belesky

    2016-06-01

    Full Text Available Grasslands, including managed grazinglands, represent one of the largest ecosystems on the planet. Managed grazinglands in particular tend to occupy marginal climatic and edaphic resource zones, thus exacerbating responses in net primary productivity relative to changes in system resources, including anthropogenic factors. Climate dynamism, as evident from the fossil record, appears to be a putative feature of our planet. Recent global trends in temperature and precipitation patterns seem to differ from long-term patterns and have been associated with human activities linked with increased greenhouse gas emissions; specifically CO2. Thus grasslands, with their diverse floristic components, and interaction with and dependence upon herbivores, have a remarkable ability to persist and sustain productivity in response to changing resource conditions. This resistance and resilience to change, including uncertain long-term weather conditions, establishes managed grasslands as an important means of protecting food security. We review responses of grassland communities across regions of the USA and consider the responses in productivity and system function with respect to climatic variation. Research is needed to identify plant resources and management technologies that strengthen our ability to capitalize upon physiological and anatomical features prevalent in grassland communities associated with varying growing conditions.

  20. Air quality and human health impacts of grasslands and shrublands in the United States

    Science.gov (United States)

    Gopalakrishnan, Varsha; Hirabayashi, Satoshi; Ziv, Guy; Bakshi, Bhavik R.

    2018-06-01

    Vegetation including canopy, grasslands, and shrublands can directly sequester pollutants onto the plant surface, resulting in an improvement in air quality. Until now, several studies have estimated the pollution removal capacity of canopy cover at the level of a county, but no such work exists for grasslands and shrublands. This work quantifies the air pollution removal capacity of grasslands and shrublands at the county-level in the United States and estimates the human health benefits associated with pollution removal using the i-Tree Eco model. Sequestration of pollutants is estimated based on the Leaf Area Index (LAI) obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) derived dataset estimates of LAI and the percentage land cover obtained from the National Land Cover Database (NLCD) for the year 2010. Calculation of pollution removal capacity using local environmental data indicates that grasslands and shrublands remove a total of 6.42 million tonnes of air pollutants in the United States and the associated monetary benefits total 268 million. Human health impacts and associated monetary value due to pollution removal was observed to be significantly high in urban areas indicating that grasslands and shrublands are equally critical as canopy in improving air quality and human health in urban regions.

  1. Factors affecting the ozone sensitivity of temperate European grasslands: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Bassin, S. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Air Pollution/Climate Group, Reckenholzstrasse 191, CH-8046 Zurich (Switzerland)]. E-mail: seraina.bassin@fal.admin.ch; Volk, M. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Air Pollution/Climate Group, Reckenholzstrasse 191, CH-8046 Zurich (Switzerland); Fuhrer, J. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Air Pollution/Climate Group, Reckenholzstrasse 191, CH-8046 Zurich (Switzerland)

    2007-04-15

    This overview of experimentally induced effects of ozone aims to identify physiological and ecological principles, which can be used to classify the sensitivity to ozone of temperate grassland communities in Europe. The analysis of data from experiments with single plants, binary mixtures and multi-species communities illustrates the difficulties to relate individual responses to communities, and thus to identify grassland communities most at risk. Although there is increasing evidence that communities can be separated into broad classes of ozone sensitivity, the database from experiments under realistic conditions with representative systems is too small to draw firm conclusions. But it appears that risk assessments, based on results from individuals or immature mixtures exposed in chambers, are only applicable to intensively managed, productive grasslands, and that the risk of ozone damage for most of perennial grasslands with lower productivity tends to be less than previously expected. - An overview of experimentally induced ozone effects suggests that temperate grasslands could be separated into broad classes of ozone sensitivity based on physiological and ecological principles.

  2. Factors affecting the ozone sensitivity of temperate European grasslands: An overview

    International Nuclear Information System (INIS)

    Bassin, S.; Volk, M.; Fuhrer, J.

    2007-01-01

    This overview of experimentally induced effects of ozone aims to identify physiological and ecological principles, which can be used to classify the sensitivity to ozone of temperate grassland communities in Europe. The analysis of data from experiments with single plants, binary mixtures and multi-species communities illustrates the difficulties to relate individual responses to communities, and thus to identify grassland communities most at risk. Although there is increasing evidence that communities can be separated into broad classes of ozone sensitivity, the database from experiments under realistic conditions with representative systems is too small to draw firm conclusions. But it appears that risk assessments, based on results from individuals or immature mixtures exposed in chambers, are only applicable to intensively managed, productive grasslands, and that the risk of ozone damage for most of perennial grasslands with lower productivity tends to be less than previously expected. - An overview of experimentally induced ozone effects suggests that temperate grasslands could be separated into broad classes of ozone sensitivity based on physiological and ecological principles

  3. Next Generation Nuclear Plant Phenomena Identification and Ranking Tables (PIRTs) Volume 5: Graphite PIRTs

    International Nuclear Information System (INIS)

    Burchell, Timothy D.; Bratton, Rob; Marsden, Barry; Srinivasan, Makuteswara; Penfield, Scott; Mitchell, Mark; Windes, Will

    2008-01-01

    Here we report the outcome of the application of the Nuclear Regulatory Commission (NRC) Phenomena Identification and Ranking Table (PIRT) process to the issue of nuclear-grade graphite for the moderator and structural components of a next generation nuclear plant (NGNP), considering both routine (normal operation) and postulated accident conditions for the NGNP. The NGNP is assumed to be a modular high-temperature gas-cooled reactor (HTGR), either a gas-turbine modular helium reactor (GTMHR) version (a prismatic-core modular reactor (PMR)] or a pebble-bed modular reactor (PBMR) version (a pebble bed reactor (PBR)] design, with either a direct- or indirect-cycle gas turbine (Brayton cycle) system for electric power production, and an indirect-cycle component for hydrogen production. NGNP design options with a high-pressure steam generator (Rankine cycle) in the primary loop are not considered in this PIRT. This graphite PIRT was conducted in parallel with four other NRC PIRT activities, taking advantage of the relationships and overlaps in subject matter. The graphite PIRT panel identified numerous phenomena, five of which were ranked high importance-low knowledge. A further nine were ranked with high importance and medium knowledge rank. Two phenomena were ranked with medium importance and low knowledge, and a further 14 were ranked medium importance and medium knowledge rank. The last 12 phenomena were ranked with low importance and high knowledge rank (or similar combinations suggesting they have low priority). The ranking/scoring rationale for the reported graphite phenomena is discussed. Much has been learned about the behavior of graphite in reactor environments in the 60-plus years since the first graphite rectors went into service. The extensive list of references in the Bibliography is plainly testament to this fact. Our current knowledge base is well developed. Although data are lacking for the specific grades being considered for Generation IV (Gen IV

  4. plantiSMASH: automated identification, annotation and expression analysis of plant biosynthetic gene clusters

    DEFF Research Database (Denmark)

    Kautsar, Satria A.; Suarez Duran, Hernando G.; Blin, Kai

    2017-01-01

    exploration of the nature and dynamics of gene clustering in plant metabolism. Moreover, spurred by the continuing decrease in costs of plant genome sequencing, they will allow genome mining technologies to be applied to plant natural product discovery. The plantiSMASH web server, precalculated results...

  5. Discrimination of grassland species and their classification in botanical families by laboratory scale hyperspectral imaging NIR: preliminary results

    Science.gov (United States)

    The objective of this study was to discriminate by on-line hyperspectral imaging, taxonomic plant families comprised of different grassland species. Plants were collected from semi-natural meadows of the National Apuseni Park, Apuseni Mountains, Gârda area (Romania) according to botanical families. ...

  6. Small-scale shifting mosaics of two dominant grassland species: the possible role of soil-borne pathogens

    NARCIS (Netherlands)

    Olff, H.; Hoorens, B.; De Goede, R.G.M.; Van der Putten, W.H.; Gleichman, J.M.

    2000-01-01

    We analyzed the dynamics of dominant plant species in a grazed grassland over 17 years, and investigated whether local shifts in these dominant species, leading to vegetation mosaics, could be attributed to interactions between plants and soil-borne pathogens. We found that Festuca rubra and Carer

  7. Small-scale shifting mosaics of two dominant grassland species : the possible role of soil-borne pathogens

    NARCIS (Netherlands)

    Olff, H.; Hoorens, B.; Goede, R.G.M. de; Putten, W.H. van der; Gleichman, J.M.

    2000-01-01

    We analyzed the dynamics of dominant plant species in a grazed grassland over 17 years, and investigated whether local shifts in these dominant species, leading to vegetation mosaics, could be attributed to interactions between plants and soil-borne pathogens. We found that Festuca rubra and Carex

  8. Soil seed-bank composition reveals the land-use history of calcareous grasslands

    Science.gov (United States)

    Karlík, Petr; Poschlod, Peter

    2014-07-01

    We compared soil seed banks and vegetation of recent (established on abandoned arable fields) and ancient (continuously managed as pastures at least since 1830) calcareous grasslands if there is any impact of former arable field use. The study was carried out in two regions of Southern Germany with well-preserved dry grassland vegetation: the western Jurassic mountains (Kaltes Feld) and the climatically drier eastern part of Southern Germany (Kallmünz). Total number of species in the seed bank was similar in both regions, but species composition partly differed, reflecting phytogeographical differences between the regions. The total number of emerged seedlings showed a large disparity (5457 compared to 2523 seedlings/m2 in Kaltes Feld and Kallmünz, respectively). Though there were differences in seed bank composition and size, we found a uniform pattern of plant traits (affiliation to phytosociological groups, Raunkiaer plant life-forms and seed longevity), which depended on the age of the grassland. The main conclusion is that seed banks in contemporary calcareous grasslands still reflect the history of former land use - in this case arable cultivation, even though it occurred a long time ago (up to 150 years). Indicators of former arable fields are germinable seeds of weeds which have persisted in the soil to the present. By contrast, weedy species are completely absent from the seed banks of ancient grasslands. Soil seed banks of recent grasslands may be of substantial conservation importance because they may store seeds of rare and endangered weed species such as Kickxia spuria, Silene noctiflora and Stachys annua, the majority of which have already gone extinct from the current vegetation of the study sites.

  9. The development of small-scale mechanization means positioning algorithm using radio frequency identification technology in industrial plants

    Science.gov (United States)

    Astafiev, A.; Orlov, A.; Privezencev, D.

    2018-01-01

    The article is devoted to the development of technology and software for the construction of positioning and control systems for small mechanization in industrial plants based on radio frequency identification methods, which will be the basis for creating highly efficient intelligent systems for controlling the product movement in industrial enterprises. The main standards that are applied in the field of product movement control automation and radio frequency identification are considered. The article reviews modern publications and automation systems for the control of product movement developed by domestic and foreign manufacturers. It describes the developed algorithm for positioning of small-scale mechanization means in an industrial enterprise. Experimental studies in laboratory and production conditions have been conducted and described in the article.

  10. A comunidade de abelhas (Hymenoptera, Apidae s. l. em uma área restrita de campo natural no Parque Estadual de Vila Velha, Paraná: diversidade, fenologia e fontes florais de alimento The bee community (Hymenoptera, Apidae s. l. in a restricted area of native grassland in the Vila Velha State Park, Paraná: diversity, phenology and food plants

    Directory of Open Access Journals (Sweden)

    Rodrigo B. Gonçalves

    2005-12-01

    Full Text Available Coletas sistemáticas de abelhas em uma área restrita no Parque Estadual de Vila Velha, Paraná, no período de outubro de 2002 a outubro de 2003, resultaram em 1552 espécimes pertencentes a 181 espécies. Estas espécies estão distribuídas em 58 gêneros, 24 tribos e 5 subfamílias. As plantas visitadas correspondem a 113 espécies, em 72 gêneros e 38 famílias. Megachile com 20 espécies foi o gênero mais rico e Ceratina o gênero mais abundante dentre os gêneros nativos. Apis mellifera foi a espécie mais coletada, correspondendo a 28% do total de indivíduos, e Bombus atratus foi a espécie mais abundante dentre as abelhas nativas. A riqueza e a equitabilidade nos meses foram variáveis, sendo março o mais rico e novembro o de maior equitabilidade. Apesar de tradicionalmente considerados parte das estepes sulinas, os campos de Vila Velha apresentam uma fauna de abelhas contendo várias espécies típicas de cerrado. O igual número de espécies entre as subfamílias Apinae e Halictinae também apontam para uma peculiaridade de sua fauna. Listas de abelhas e plantas coletadas são apresentadas em anexo.A standardized survey of bees visiting blooming plants in an area covered by natural grasslands in the Vila Velha State Park was conducted from October, 2002, to October, 2003. A total of 1552 specimens belonging to 181 species were collected. These species are distributed in 58 genera, 24 tribes and 5 subfamilies. The visited plants belong to 113 species, in 72 genera and 38 families. Megachile, with 20 species, was the richest genus, while Ceratina was the most abundant native genus. Apis mellifera was the most abundant species, with 28% of all bees collected. Among the native species, Bombus atratus was the most abundant. Monthly richness and equitability varied along the year, March being the richest, and November, the most equitable. Despite being traditionally placed within the southern steppes, the open grasslands of Vila Velha

  11. Effects of grassland management on the emission of methane from grassland on peat soils

    Energy Technology Data Exchange (ETDEWEB)

    Van Dasselaar, A. [Dept. of Soil Science and Plant Nutrition, Wageningen Agricultural Univ. (Netherlands); Oenema, O. [NMI, Wageningen (Netherlands)

    1995-11-01

    Net methane (CH{sub 4}) emissions from managed grassland on peat soils in the Netherlands have been monitored with vented closed flux chambers in the period January - June 1994. Net CH{sub 4} emissions from two intensively managed grasslands were low, in general less than 0.1 mg CH{sub 4} m{sup -2} d{sup -l}. On these sites, the effect of management was negligibly small. CH{sub 4} emission from three extensively managed grasslands in a nature preserve ranged from 0 to 185 mg CH{sub 4} m{sup -2} d{sup -l}. The results presented here indicate that CH{sub 4} emissions are 2-3 orders of magnitude higher on extensively managed grasslands than on intensively managed grasslands. 2 figs., 6 refs.

  12. Grassland canopy parameters and their relationships to remotely sensed vegetation indices in the Nebraska Sand Hills

    Science.gov (United States)

    Wylie, Bruce K.; DeJong, Donovan D.; Tieszen, Larry L.; Biondini, Mario E.

    1996-01-01

    Relationships among spectral vegetation indices and grassland biophysical parameters including the effects of varying levels of standing dead vegetation, range sites, and range plant communities were examined. Range plant communities consisting of northern mixed grass prairie and a smooth brome field as well as range sites and management in a Sand Hills bluestem prairie were sampled with a ground radiometer and for LAI, biomass, chlorophy

  13. Combining social policy and scientific knowledge with stakeholder participation can benefit on salted grassland production in Northeast China

    Science.gov (United States)

    Wang, Deli; Yang, Zhiming; Wang, Ling; Sun, Wei

    2015-04-01

    Soil salinization is a serious environmental problem across the Eurasian steppes, where millions people have been living for at least five thousand years and will still depend on it in the near future. During the last several decades, ecologists and grassland scientists have done much research on rational grassland utilization avoiding land degradation and reduction in ecological services. Meanwhile, the central and local governments took some attempts of agricultural policy and ecological subsidy to mitigate large scale land salinization in Northeast China. Fortunately, more and more farmers and stakeholders begin to adopt rational grassland management with the guidance of scientists and the help of local governments. However, up to date, there is still a gap between farmers, scientists and governments, which often negatively affect grassland production and remission of soil salinization in these areas. We conducted a case study on sustainable grassland production adapted to steppe salinization funded by EC project from 2011 to 2013. Our goal is trying to establish a mode of adaptive grassland management integrating previous scientific knowledge (grazing and seeding), current agricultural policies (ecological subsidy) and stakeholders' participation or performance. The study showed that: A. Despite of some grassland utilization techniques available for stakeholders (regulating stocking rate and seeding in pastures, or planting high quality forages), they tended to take the simplest action to enhance animal production and prevent grassland salinization; B. Compared to educating or training stakeholders, demonstration of grazing management is the most effective mean for knowledge dissemination or technology transfer; C. Ecological subsidy is absolutely welcome to the local people, and technology transfer became easier when combined with ecological subsidy; D. There was a contrasting effect in grassland production and land degradation mitigation for experimental farm

  14. A Satellite-Based Model for Simulating Ecosystem Respiration in the Tibetan and Inner Mongolian Grasslands

    Directory of Open Access Journals (Sweden)

    Rong Ge

    2018-01-01

    Full Text Available It is important to accurately evaluate ecosystem respiration (RE in the alpine grasslands of the Tibetan Plateau and the temperate grasslands of the Inner Mongolian Plateau, as it serves as a sensitivity indicator of regional and global carbon cycles. Here, we combined flux measurements taken between 2003 and 2013 from 16 grassland sites across northern China and the corresponding MODIS land surface temperature (LST, enhanced vegetation index (EVI, and land surface water index (LSWI to build a satellite-based model to estimate RE at a regional scale. First, the dependencies of both spatial and temporal variations of RE on these biotic and climatic factors were examined explicitly. We found that plant productivity and moisture, but not temperature, can best explain the spatial pattern of RE in northern China’s grasslands; while temperature plays a major role in regulating the temporal variability of RE in the alpine grasslands, and moisture is equally as important as temperature in the temperate grasslands. However, the moisture effect on RE and the explicit representation of spatial variation process are often lacking in most of the existing satellite-based RE models. On this basis, we developed a model by comprehensively considering moisture, temperature, and productivity effects on both temporal and spatial processes of RE, and then, we evaluated the model performance. Our results showed that the model well explained the observed RE in both the alpine (R2 = 0.79, RMSE = 0.77 g C m−2 day−1 and temperate grasslands (R2 = 0.75, RMSE = 0.60 g C m−2 day−1. The inclusion of the LSWI as the water-limiting factor substantially improved the model performance in arid and semi-arid ecosystems, and the spatialized basal respiration rate as an indicator for spatial variation largely determined the regional pattern of RE. Finally, the model accurately reproduced the seasonal and inter-annual variations and spatial variability of RE, and it avoided

  15. Grassland degradation caused by tourism activities in Hulunbuir, Inner Mongolia, China

    International Nuclear Information System (INIS)

    Le, C; Ikazaki, K; Siriguleng; Kosaki, T; Kadono, A

    2014-01-01

    The recent increase in the number of tourists has raised serious concerns about grassland degradation by tourism activities in Inner Mongolia. Thus, we evaluated the effects of tourism activities on the vegetation and soil in Hulunbuir grassland. We identified all the plant species, measured the number and height of plant and plant coverage rate, and calculated species diversity, estimated above-ground biomass in use plot and non-use plot. We also measured soil hardness, and collected soil samples for physical and chemical analysis in both plots. The obtained results were as follows: a) the height of the dominant plants, plant coverage rate, species diversity, and above-ground biomass were significantly lower in use plot than in non-use plot, b) Carex duriuscula C.A.Mey., indicator plant for soil degradation, was dominant in use plot, c) soil hardness was significantly higher in use plot than in non-use plot, and spatial dependence of soil hardness was only found in the use plot, d) CEC, TC, TN and pH in the topsoil were significantly lower in use plot than non-use plot. On the basis of the results, we concluded that the tourism activities can be another major cause of the grassland degradation in Inner Mongolia

  16. Grassland degradation caused by tourism activities in Hulunbuir, Inner Mongolia, China

    Science.gov (United States)

    Le, C.; Ikazaki, K.; Siriguleng; Kadono, A.; Kosaki, T.

    2014-02-01

    The recent increase in the number of tourists has raised serious concerns about grassland degradation by tourism activities in Inner Mongolia. Thus, we evaluated the effects of tourism activities on the vegetation and soil in Hulunbuir grassland. We identified all the plant species, measured the number and height of plant and plant coverage rate, and calculated species diversity, estimated above-ground biomass in use plot and non-use plot. We also measured soil hardness, and collected soil samples for physical and chemical analysis in both plots. The obtained results were as follows: a) the height of the dominant plants, plant coverage rate, species diversity, and above-ground biomass were significantly lower in use plot than in non-use plot, b) Carex duriuscula C.A.Mey., indicator plant for soil degradation, was dominant in use plot, c) soil hardness was significantly higher in use plot than in non-use plot, and spatial dependence of soil hardness was only found in the use plot, d) CEC, TC, TN and pH in the topsoil were significantly lower in use plot than non-use plot. On the basis of the results, we concluded that the tourism activities can be another major cause of the grassland degradation in Inner Mongolia.

  17. Plant Community and Soil Environment Response to Summer Fire in the Northern Great Plains

    Science.gov (United States)

    Fire is a keystone process in many ecosystems, especially grasslands. However, documentation of plant community and soil environment responses to fire is limited for semiarid grasslands relative to that for mesic grasslands. Replicated summer fire research is lacking, but much needed because summe...

  18. Preliminary Research on Grassland Fine-classification Based on MODIS

    International Nuclear Information System (INIS)

    Hu, Z W; Zhang, S; Yu, X Y; Wang, X S

    2014-01-01

    Grassland ecosystem is important for climatic regulation, maintaining the soil and water. Research on the grassland monitoring method could provide effective reference for grassland resource investigation. In this study, we used the vegetation index method for grassland classification. There are several types of climate in China. Therefore, we need to use China's Main Climate Zone Maps and divide the study region into four climate zones. Based on grassland classification system of the first nation-wide grass resource survey in China, we established a new grassland classification system which is only suitable for this research. We used MODIS images as the basic data resources, and use the expert classifier method to perform grassland classification. Based on the 1:1,000,000 Grassland Resource Map of China, we obtained the basic distribution of all the grassland types and selected 20 samples evenly distributed in each type, then used NDVI/EVI product to summarize different spectral features of different grassland types. Finally, we introduced other classification auxiliary data, such as elevation, accumulate temperature (AT), humidity index (HI) and rainfall. China's nation-wide grassland classification map is resulted by merging the grassland in different climate zone. The overall classification accuracy is 60.4%. The result indicated that expert classifier is proper for national wide grassland classification, but the classification accuracy need to be improved

  19. Some Insights on Grassland Health Assessment Based on Remote Sensing

    Directory of Open Access Journals (Sweden)

    Dandan Xu

    2015-01-01

    Full Text Available Grassland ecosystem is one of the largest ecosystems, which naturally occurs on all continents excluding Antarctica and provides both ecological and economic functions. The deterioration of natural grassland has been attracting many grassland researchers to monitor the grassland condition and dynamics for decades. Remote sensing techniques, which are advanced in dealing with the scale constraints of ecological research and provide temporal information, become a powerful approach of grassland ecosystem monitoring. So far, grassland health monitoring studies have mostly focused on different areas, for example, productivity evaluation, classification, vegetation dynamics, livestock carrying capacity, grazing intensity, natural disaster detecting, fire, climate change, coverage assessment and soil erosion. However, the grassland ecosystem is a complex system which is formed by soil, vegetation, wildlife and atmosphere. Thus, it is time to consider the grassland ecosystem as an entity synthetically and establish an integrated grassland health monitoring system to combine different aspects of the complex grassland ecosystem. In this review, current grassland health monitoring methods, including rangeland health assessment, ecosystem health assessment and grassland monitoring by remote sensing from different aspects, are discussed along with the future directions of grassland health assessment.

  20. Some insights on grassland health assessment based on remote sensing.

    Science.gov (United States)

    Xu, Dandan; Guo, Xulin

    2015-01-29

    Grassland ecosystem is one of the largest ecosystems, which naturally occurs on all continents excluding Antarctica and provides both ecological and economic functions. The deterioration of natural grassland has been attracting many grassland researchers to monitor the grassland condition and dynamics for decades. Remote sensing techniques, which are advanced in dealing with the scale constraints of ecological research and provide temporal information, become a powerful approach of grassland ecosystem monitoring. So far, grassland health monitoring studies have mostly focused on different areas, for example, productivity evaluation, classification, vegetation dynamics, livestock carrying capacity, grazing intensity, natural disaster detecting, fire, climate change, coverage assessment and soil erosion. However, the grassland ecosystem is a complex system which is formed by soil, vegetation, wildlife and atmosphere. Thus, it is time to consider the grassland ecosystem as an entity synthetically and establish an integrated grassland health monitoring system to combine different aspects of the complex grassland ecosystem. In this review, current grassland health monitoring methods, including rangeland health assessment, ecosystem health assessment and grassland monitoring by remote sensing from different aspects, are discussed along with the future directions of grassland health assessment.

  1. Testing the algorithms for automatic identification of errors on the measured quantities of the nuclear power plant. Verification tests

    International Nuclear Information System (INIS)

    Svatek, J.

    1999-12-01

    During the development and implementation of supporting software for the control room and emergency control centre at the Dukovany nuclear power plant it appeared necessary to validate the input quantities in order to assure operating reliability of the software tools. Therefore, the development of software for validation of the measured quantities of the plant data sources was initiated, and the software had to be debugged and verified. The report contains the proposal for and description of the verification tests for testing the algorithms of automatic identification of errors on the observed quantities of the NPP by means of homemade validation software. In particular, the algorithms treated serve the validation of the hot leg temperature at primary circuit loop no. 2 or 4 at the Dukovany-2 reactor unit using data from the URAN and VK3 information systems, recorded during 3 different days. (author)

  2. Identification of Physiological Substrates and Binding Partners of the Plant Mitochondrial Protease FTSH4 by the Trapping Approach.

    Science.gov (United States)

    Opalińska, Magdalena; Parys, Katarzyna; Jańska, Hanna

    2017-11-18

    Maintenance of functional mitochondria is vital for optimal cell performance and survival. This is accomplished by distinct mechanisms, of which preservation of mitochondrial protein homeostasis fulfills a pivotal role. In plants, inner membrane-embedded i -AAA protease, FTSH4, contributes to the mitochondrial proteome surveillance. Owing to the limited knowledge of FTSH4's in vivo substrates, very little is known about the pathways and mechanisms directly controlled by this protease. Here, we applied substrate trapping coupled with mass spectrometry-based peptide identification in order to extend the list of FTSH4's physiological substrates and interaction partners. Our analyses revealed, among several putative targets of FTSH4, novel (mitochondrial pyruvate carrier 4 (MPC4) and Pam18-2) and known (Tim17-2) substrates of this protease. Furthermore, we demonstrate that FTSH4 degrades oxidatively damaged proteins in mitochondria. Our report provides new insights into the function of FTSH4 in the maintenance of plant mitochondrial proteome.

  3. Toxicity Identification and Evaluation for the Effluent from Wastewater Treatment Plant in Industrial Complex using D.magna

    Science.gov (United States)

    Lee, S.; Keum, H.; Chun Sang, H.

    2015-12-01

    In recent years, the interests on the impacts of industrial wastewater on aquatic ecosystem have increased with concern about ecosystem protection and human health. Whole effluent toxicity tests are used to monitor toxicity by unknown toxic chemicals as well as conventional pollutants from industrial effluent discharges. This study describes the application of TIE (toxicity identification evaluation) procedures to an acutely toxic effluent from a wastewater treatment plant in industrial complex which was toxic to Daphnia magna. In TIE phase I (characterization step), the toxic effects by heavy metals, organic compounds, oxidants, volatile organic compounds, suspended solids and ammonia were screened and revealed that the source of toxicity is far from these toxicants group. Chemical analysis (TIE phase II) on TDS showed that the concentration of chloride ion (6,900 mg/L) was substantially higher than that predicted from EC50 for D. magna. In confirmation step (TIE phase III), chloride ion was demonstrated to be main toxicant in this effluent by the spiking approach, species sensitivity approach and deletion approach. Calcium, potassium, magnesium, sodium, fluorine, sulfate ion concentration (450, 100, 80, 5,300, 0.66, 2,200mg/L) was not shown toxicity from D. magna. Finally, we concluded that chloride was the most contributing toxicant in the waste water treatment plant. Further research activities are needed for technical support of toxicity identification and evaluation on the various types of wastewater treatment plant discharge in Korea. Keywords : TIE, D. magna, Industrial waste water Acknowledgement This research was supported by a grant (15IFIP-B089908-02) from Plant Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government

  4. Importance and functions of European grasslands.

    Science.gov (United States)

    Carlier, L; De Vliegher, A; Van Cleemput, O; Boeckx, P

    2005-01-01

    The European agricultural policy is not simple and needs to accommodate also social and environmental requirements. Grassland will continue to be an important form of land use in Europe, but with increased diversity in management objectives and systems used. Besides its role as basic nutrient for herbivores and ruminants grasslands have opportunities for adding value by exploiting positive health characteristics in animal products from grassland and through the delivery of environmental benefits. In fact grasslands contribute to a high degree to the struggle against erosion and to the regularizing of water regimes, to the purification of fertilizers and pesticides and to biodiversity. Finally they have aesthetic role and recreational function as far as they provide public access that other agricultural uses do not allow. But even for grassland it is very difficult to create a good frame for its different tasks (1) the provision of forage for livestock, (2) protection and conservation of soil and water resources, (3) furnishing a habitat for wildlife, both flora and fauna and (4) contribution to the attractiveness of the landscape. Nevertheless it is the only crop, able to fulfil so many tasks and to fit so many requirements.

  5. Heuristic learning parameter identification for surveillance and diagnostics of nuclear power plants

    International Nuclear Information System (INIS)

    Machado, E.L.

    1983-01-01

    A new method of heuristic reinforcement learning was developed for parameter identification purposes. In essence, this new parameter identification technique is based on the idea of breaking a multidimensional search for the minimum of a given functional into a set of unidirectional searches in parameter space. Each search situation is associated with one block in a memory organized into cells, where the information learned about the situations is stored (e.g. the optimal directions in parameter space). Whenever the search falls into an existing memory cell, the system chooses the learned direction. For new search situations, the system creates additional memory cells. This algorithm imitates the following cognitive process: 1) characterize a situation, 2) select an optimal action, 3) evaluate the consequences of the action, and 4) memorize the results for future use. As a result, this algorithm is trainable in the sense that it can learn from previous experience within a specific class of parameter identification problems

  6. The relationships between biodiversity and ecosystem services and the effects of grazing cessation in semi-natural grasslands

    Directory of Open Access Journals (Sweden)

    S. Wehn

    2018-04-01

    Full Text Available Land use change can affect biodiversity, and this has an impact on ecosystem services (ESs, but the relationships between biodiversity and ESs are complex and poorly understood. Biodiversity is declining due to the abandonment of extensively grazed semi-natural grasslands.We therefore aim to explore relationships between biodiversity and ESs provided by extensively managed semi-natural grasslands. Focusing on vascular plant species richness, as well as the ESs fodder quantity, quality, and stability, allergy control, climate regulation, nutrient cycling, pollination, and aesthetic appreciation, we carried out botanical field surveys of 28 paired extensively grazed and abandoned semi-natural grassland plots, with four subplots of 4 m2 in each plot. The management of the semi-natural grasslands is and has been at low intensity. We calculated the influence of abandonment on the ES indicators, measured the correlation between the biodiversity measure of vascular plant species richness and ES indicators, and finally determined how the relationships between plant species richness and the ES indicators were affected by the cessation of the extensive management.ES indicators are often, but not always, positively correlated with species richness. Cessation of extensive grazing has both negative and positive effects on ES indicators but the relationships between species richness and ES indicators are often different in extensively managed and abandoned semi-natural grasslands. The relationships between species richness and ES indicators are less pronounced in the extensively managed semi-natural grassland than for the abandoned. One possible reason for this outcome is high functional redundancy in the extensively managed semi-natural grasslands.

  7. USING CALIBRATED RGB IMAGERY FROM LOW-COST UAVS FOR GRASSLAND MONITORING: CASE STUDY AT THE RENGEN GRASSLAND EXPERIMENT (RGE), GERMANY

    OpenAIRE

    U. Lussem; J. Hollberg; J. Hollberg; J. Menne; J. Schellberg; J. Schellberg; G. Bareth; G. Bareth

    2017-01-01

    Monitoring the spectral response of intensively managed grassland throughout the growing season allows optimizing fertilizer inputs by monitoring plant growth. For example, site-specific fertilizer application as part of precision agriculture (PA) management requires information within short time. But, this requires field-based measurements with hyper- or multispectral sensors, which may not be feasible on a day to day farming practice. Exploiting the information of RGB images from consumer g...

  8. Roles of Arbuscular Mycorrhizal Fungi and Soil Abiotic Conditions in the Establishment of a Dry Grassland Community.

    Directory of Open Access Journals (Sweden)

    Jana Knappová

    Full Text Available The importance of soil biota in the composition of mature plant communities is commonly acknowledged. In contrast, the role of soil biota in the early establishment of new plant communities and their relative importance for soil abiotic conditions are still poorly understood.The aim of this study was to understand the effects of soil origin and soil fungal communities on the composition of a newly established dry grassland plant community. We used soil from two different origins (dry grassland and abandoned field with different pH and nutrient and mineral content. Grassland microcosms were established by sowing seeds of 54 species of dry grassland plants into the studied soils. To suppress soil fungi, half of the pots were regularly treated with fungicide. In this way, we studied the independent and combined effects of soil origin and soil community on the establishment of dry grassland communities.The effect of suppressing the soil fungal community on the richness and composition of the plant communities was much stronger than the effect of soil origin. Contrary to our expectations, the effects of these two factors were largely additive, indicating the same degree of importance of soil fungal communities in the establishment of species-rich plant communities in the soils from both origins. The negative effect of suppressing soil fungi on species richness, however, occurred later in the soil from the abandoned field than in the soil from the grassland. This result likely occurred because the negative effects of the suppression of fungi in the field soil were caused mainly by changes in plant community composition and increased competition. In contrast, in the grassland soil, the absence of soil fungi was limiting for plants already at the early stages of their establishment, i.e., in the phases of germination and early recruitment. While fungicide affects not only arbuscular mycorrhizal fungi but also other biota, our data indicate that changes

  9. AtNEA1-identification and characterization of a novel plant nuclear ...

    African Journals Online (AJOL)

    In animal and yeast cells, a cross nuclear envelope structure linker of nucleoskeleton and cytoskeleton (LINC) is formed by outer nuclear membrane SUN proteins and inner nuclear membrane KASH proteins. However, little information was acquired about plant SUN-KASH structure until they were found in plant SUN ...

  10. Airborne multispectral identification of individual cotton plants using consumer-grade cameras

    Science.gov (United States)

    Although multispectral remote sensing using consumer-grade cameras has successfully identified fields of small cotton plants, improvements to detection sensitivity are needed to identify individual or small clusters of plants. The imaging sensor of consumer-grade cameras are based on a Bayer patter...

  11. Phase Identification and Internal Stress Analysis of Steamside Oxides on Plant Exposed Superheater Tubes

    DEFF Research Database (Denmark)

    Pantleon, Karen; Montgomery, Melanie

    2012-01-01

    During long-term, high-temperature exposure of superheater tubes in thermal power plants, various oxides are formed on the inner side (steamside) of the tubes, and oxide spallation is a serious problem for the power plant industry. Most often, oxidation in a steam atmosphere is investigated...... in laboratory experiments just mimicking the actual conditions in the power plant for simplified samples. On real plant-exposed superheater tubes, the steamside oxides are solely investigated microscopically. The feasibility of X-ray diffraction for the characterization of steamside oxidation on real plant......-exposed superheater tubes was proven in the current work; the challenges for depth-resolved phase analysis and phase-specific residual stress analysis at the inner side of the tubes with concave surface curvature are discussed. Essential differences between the steamside oxides formed on two different steels...

  12. Lights, camera…citizen science: assessing the effectiveness of smartphone-based video training in invasive plant identification.

    Directory of Open Access Journals (Sweden)

    Jared Starr

    Full Text Available The rapid growth and increasing popularity of smartphone technology is putting sophisticated data-collection tools in the hands of more and more citizens. This has exciting implications for the expanding field of citizen science. With smartphone-based applications (apps, it is now increasingly practical to remotely acquire high quality citizen-submitted data at a fraction of the cost of a traditional study. Yet, one impediment to citizen science projects is the question of how to train participants. The traditional "in-person" training model, while effective, can be cost prohibitive as the spatial scale of a project increases. To explore possible solutions, we analyze three training models: 1 in-person, 2 app-based video, and 3 app-based text/images in the context of invasive plant identification in Massachusetts. Encouragingly, we find that participants who received video training were as successful at invasive plant identification as those trained in-person, while those receiving just text/images were less successful. This finding has implications for a variety of citizen science projects that need alternative methods to effectively train participants when in-person training is impractical.

  13. Nuclear power plant life management. An overview of identification of key components in relation with degradation mechanism - IAEA guidelines presentation

    International Nuclear Information System (INIS)

    Bezdikian, Georges

    2005-01-01

    Nuclear Power Plant (NPP) lifetime has a direct bearing on the cost of the electricity generated from it. The annual unit cost of electricity is dependent upon the operational time, and also annual costs and the capital cost assumptions function of Euros/kw. If the actual NPP lifetime has been underestimated then an economic penalty could be incurred. But the ageing degradation, of nuclear power plants is an important aspect that requires to be addressed to ensure: - that necessary safety margins are maintained throughout service life; - the adequate reliability and therefore the economic viability of older plants is maintained; - that unforeseen an uncontrolled degradation of critical plant components does not foreshorten the plant lifetime. Accommodating the inevitable obsolescence of some components has also to be addressed during plant life. Plant lifetime management requires the identification and life assessment of those components which not only limit the lifetime of the plant but also those which cannot be reasonably replaced. The planned replacement of major or 'key' components needs to be considered - where economic considerations will largely dictate replacement or the alternative strategy of power plant decommissioning. The necessary but timely planning for maintenance and replacements is a necessary consideration so that functions and reliability are maintained. The reasons for the current increasing attention in the area of plant life management are diverse and range from the fact that many of the older plants are approaching for the oldest plants more than 30 years in operation, and for important number of NPPs between 20 and 30 years. The impact of plant life management on the economics of generating electricity is the subject of ongoing studies and it can readily be seen that there can be both savings and additional costs associated with these activities. Not all degradation processes will be of significance in eroding safety margins and there is a

  14. Distinguishing Intensity Levels of Grassland Fertilization Using Vegetation Indices

    OpenAIRE

    Jens L. Hollberg; Jürgen Schellberg

    2017-01-01

    Monitoring the reaction of grassland canopies on fertilizer application is of major importance to enable a well-adjusted management supporting a sustainable production of the grass crop. Up to date, grassland managers estimate the nutrient status and growth dynamics of grasslands by costly and time-consuming field surveys, which only provide low temporal and spatial data density. Grassland mapping using remotely-sensed Vegetation Indices (VIs) has the potential to contribute to solving these ...

  15. Bird communities and biomass yields in potential bioenergy grasslands.

    Directory of Open Access Journals (Sweden)

    Peter J Blank

    Full Text Available Demand for bioenergy is increasing, but the ecological consequences of bioenergy crop production on working lands remain unresolved. Corn is currently a dominant bioenergy crop, but perennial grasslands could produce renewable bioenergy resources and enhance biodiversity. Grassland bird populations have declined in recent decades and may particularly benefit from perennial grasslands grown for bioenergy. We asked how breeding bird community assemblages, vegetation characteristics, and biomass yields varied among three types of potential bioenergy grassland fields (grass monocultures, grass-dominated fields, and forb-dominated fields, and assessed tradeoffs between grassland biomass production and bird habitat. We also compared the bird communities in grassland fields to nearby cornfields. Cornfields had few birds compared to perennial grassland fields. Ten bird Species of Greatest Conservation Need (SGCN were observed in perennial grassland fields. Bird species richness and total bird density increased with forb cover and were greater in forb-dominated fields than grass monocultures. SGCN density declined with increasing vertical vegetation density, indicating that tall, dense grassland fields managed for maximum biomass yield would be of lesser value to imperiled grassland bird species. The proportion of grassland habitat within 1 km of study sites was positively associated with bird species richness and the density of total birds and SGCNs, suggesting that grassland bioenergy fields may be more beneficial for grassland birds if they are established near other grassland parcels. Predicted total bird density peaked below maximum biomass yields and predicted SGCN density was negatively related to biomass yields. Our results indicate that perennial grassland fields could produce bioenergy feedstocks while providing bird habitat. Bioenergy grasslands promote agricultural multifunctionality and conservation of biodiversity in working landscapes.

  16. Ornamental Eudicotyledons from grasslands of Pampa biome in Rio Grande do Sul

    Directory of Open Access Journals (Sweden)

    Ana De Araújo Carrion

    2012-10-01

    Full Text Available The present study aims at investigating the group of Eudicotyledons native plants with ornamental potential of grasslands from the Pampa biome in the south of Brazil. The Pampa presents a high level of biodiversity; however, it requires studies related to the richness of vascular plants and its biological and ecological knowledge. The purpose of this work is to elaborate a preliminary inventory of this group of plants, analyzing the ornamental potential of each specie and indicating those that could be considered as being priorities for the purpose of sustainable use with this objective. Some grassland species were selected through the search for information in herbarium registers, national and international works about decorative plants, floristic surveys, besides the authors´ practical knowledge. Some parameters and values were associated, aiming at reducing the subjectivity of the choice. The survey resulted in a list of 177 species distributed in 36 families and 101 genera. Among these species, ten presented high ornamental potential. These data show that the richness of the grassland native ornamental flora is high, even though its use is poorly known. The use of these plants, if in a sustainable manner, can produce economic and ecological benefits.

  17. In silico identification of anti-cancer compounds and plants from traditional Chinese medicine database

    Science.gov (United States)

    Dai, Shao-Xing; Li, Wen-Xing; Han, Fei-Fei; Guo, Yi-Cheng; Zheng, Jun-Juan; Liu, Jia-Qian; Wang, Qian; Gao, Yue-Dong; Li, Gong-Hua; Huang, Jing-Fei

    2016-05-01

    There is a constant demand to develop new, effective, and affordable anti-cancer drugs. The traditional Chinese medicine (TCM) is a valuable and alternative resource for identifying novel anti-cancer agents. In this study, we aim to identify the anti-cancer compounds and plants from the TCM database by using cheminformatics. We first predicted 5278 anti-cancer compounds from TCM database. The top 346 compounds were highly potent active in the 60 cell lines test. Similarity analysis revealed that 75% of the 5278 compounds are highly similar to the approved anti-cancer drugs. Based on the predicted anti-cancer compounds, we identified 57 anti-cancer plants by activity enrichment. The identified plants are widely distributed in 46 genera and 28 families, which broadens the scope of the anti-cancer drug screening. Finally, we constructed a network of predicted anti-cancer plants and approved drugs based on the above results. The network highlighted the supportive role of the predicted plant in the development of anti-cancer drug and suggested different molecular anti-cancer mechanisms of the plants. Our study suggests that the predicted compounds and plants from TCM database offer an attractive starting point and a broader scope to mine for potential anti-cancer agents.

  18. Ecosystem development in roadside grasslands: biotic control, plant–soil interactions and dispersal limitations

    Science.gov (United States)

    García-Palacios, Pablo; Bowker, Matthew A.; Maestre, Fernando T.; Soliveres, Santiago; Valladares, Fernando; Papadopoulos, Jorge; Escudero, Adrián

    2015-01-01

    Roadside grasslands undergoing secondary succession are abundant, and represent ecologically meaningful examples of novel, human-created ecosystems. Interactions between plant and soil communities (hereafter plant–soil interactions) are of major importance in understanding the role of biotic control in ecosystem functioning, but little is known about these links in the context of ecosystem restoration and succession. The assessment of the key biotic communities and interactions driving ecosystem development will help practitioners to better allocate the limited resources devoted to roadside grassland restoration. We surveyed roadside grasslands from three successional stages (0–2, 7–9 and > 20 years) in two Mediterranean regions of Spain. Structural equation modeling was used to evaluate how interactions between plants, biological soil crusts [BSCs], and soil microbial functional diversity [soil microorganisms] affect indicators of ecosystem development and restoration: plant similarity to the reference ecosystem, erosion control and soil C storage and N accumulation. Changes in plant community composition along the successional gradient exerted the strongest influence on these indicators. High BSC cover was associated with high soil stability, and high soil microbial functional diversity from late-successional stages was associated with high soil fertility. Contrary to our expectations, the indirect effects of plants, mediated by either BSCs or soil microorganisms, were very weak in both regions, suggesting a minor role for plant–soil interactions upon ecosystem development indicators over long periods. Our results suggest that natural vegetation dynamics effectively improved ecosystem development within a time frame of 20 years in the grasslands evaluated. They also indicate that this time could be shortened if management actions focus on: 1) maintain well-conserved natural areas close to roadsides to enhance plant compositional changes towards late

  19. Grassland ecology and diversity (Ecologia y diversidad de pastizales)

    Science.gov (United States)

    Laurie B. Abbott

    2006-01-01

    Grasslands of the Chihuahuan Desert region are ecologically and economically important. These grasslands are valued for their rangeland, wildlife, watershed, and recreation resources. Biological diversity also raises the value of grassland communities. The potential for multiple uses within the region increases as the diversity of the resource base increases. In order...

  20. Appreciation of the functions of grasslands by Irish stakeholders

    NARCIS (Netherlands)

    Hennessy, D.; Pol-van Dasselaar, van den A.

    2014-01-01

    The European project MultiSward studied the appreciation of different functions of grasslands by European stakeholders. This paper describes the importance of grasslands for stakeholders in Ireland. Ireland currently has approximately 4.6 million ha of grassland, which is 90% of the total utilized

  1. Predation drives nesting success in moist highland grasslands: the ...

    African Journals Online (AJOL)

    By focusing on process-oriented data rather than inventory-type data, this study provides a robust understanding of the effects of agricultural management on grassland bird reproductive output in the moist highland grasslands (MHGs) of South Africa. Four-hundred and four nests of 12 grassland-breeding bird species were ...

  2. COENOLOGICAL SHIFT FOLLOWING FERTILIZATION IN MEDITERRANEAN GRASSLAND

    Directory of Open Access Journals (Sweden)

    ALESSANDRO SERAFINI SAULI

    2006-05-01

    Full Text Available In Rome both meadows of CentraI-European affinity and Mediterranean dry grasslands are presento We studied a site (Parco Regionale Urbano de] Pineto in Rome with very diverse vegetation, where species belonging to both coenologica] groups oceur. Wc fertilized a grassland with a combination of phosphorus (P and nitrogen (N. After fertilization diagDostie species of Helianthemetea guttati (Thcrophytes dccrease while species of MolinioArrhenatheretea (Hemicriptophytes increase. In a climate as that of Rome, transition between Mediterranean (with summer drought and Central European (without summer drought, nutrients availability modulates the distribution of vegetation Classes with respectively Mediterranean or Central-Europe affinities.

  3. Using Calibrated RGB Imagery from Low-Cost Uavs for Grassland Monitoring: Case Study at the Rengen Grassland Experiment (rge), Germany

    Science.gov (United States)

    Lussem, U.; Hollberg, J.; Menne, J.; Schellberg, J.; Bareth, G.

    2017-08-01

    Monitoring the spectral response of intensively managed grassland throughout the growing season allows optimizing fertilizer inputs by monitoring plant growth. For example, site-specific fertilizer application as part of precision agriculture (PA) management requires information within short time. But, this requires field-based measurements with hyper- or multispectral sensors, which may not be feasible on a day to day farming practice. Exploiting the information of RGB images from consumer grade cameras mounted on unmanned aerial vehicles (UAV) can offer cost-efficient as well as near-real time analysis of grasslands with high temporal and spatial resolution. The potential of RGB imagery-based vegetation indices (VI) from consumer grade cameras mounted on UAVs has been explored recently in several. However, for multitemporal analyses it is desirable to calibrate the digital numbers (DN) of RGB-images to physical units. In this study, we explored the comparability of the RGBVI from a consumer grade camera mounted on a low-cost UAV to well established vegetation indices from hyperspectral field measurements for applications in grassland. The study was conducted in 2014 on the Rengen Grassland Experiment (RGE) in Germany. Image DN values were calibrated into reflectance by using the Empirical Line Method (Smith & Milton 1999). Depending on sampling date and VI the correlation between the UAV-based RGBVI and VIs such as the NDVI resulted in varying R2 values from no correlation to up to 0.9. These results indicate, that calibrated RGB-based VIs have the potential to support or substitute hyperspectral field measurements to facilitate management decisions on grasslands.

  4. USING CALIBRATED RGB IMAGERY FROM LOW-COST UAVS FOR GRASSLAND MONITORING: CASE STUDY AT THE RENGEN GRASSLAND EXPERIMENT (RGE, GERMANY

    Directory of Open Access Journals (Sweden)

    U. Lussem

    2017-08-01

    Full Text Available Monitoring the spectral response of intensively managed grassland throughout the growing season allows optimizing fertilizer inputs by monitoring plant growth. For example, site-specific fertilizer application as part of precision agriculture (PA management requires information within short time. But, this requires field-based measurements with hyper- or multispectral sensors, which may not be feasible on a day to day farming practice. Exploiting the information of RGB images from consumer grade cameras mounted on unmanned aerial vehicles (UAV can offer cost-efficient as well as near-real time analysis of grasslands with high temporal and spatial resolution. The potential of RGB imagery-based vegetation indices (VI from consumer grade cameras mounted on UAVs has been explored recently in several. However, for multitemporal analyses it is desirable to calibrate the digital numbers (DN of RGB-images to physical units. In this study, we explored the comparability of the RGBVI from a consumer grade camera mounted on a low-cost UAV to well established vegetation indices from hyperspectral field measurements for applications in grassland. The study was conducted in 2014 on the Rengen Grassland Experiment (RGE in Germany. Image DN values were calibrated into reflectance by using the Empirical Line Method (Smith & Milton 1999. Depending on sampling date and VI the correlation between the UAV-based RGBVI and VIs such as the NDVI resulted in varying R2 values from no correlation to up to 0.9. These results indicate, that calibrated RGB-based VIs have the potential to support or substitute hyperspectral field measurements to facilitate management decisions on grasslands.

  5. BETA DIVERSITY AND COMMUNITY DIFFERENTIATION IN DRY PERENNIAL SAND GRASSLANDS

    Directory of Open Access Journals (Sweden)

    E. KOVACS-LANG

    2011-01-01

    Full Text Available The spatial variability of species composition was studied in perennial sand grasslands in Hungary at multiple scales. Three sites were compared along an aridity gradient. Existing differences in climate along this ca. 200 km gradient correspond to regional climate changes predicted for the next 20-30 years. Six stands of Festucetum vaginatae grasslands were selected at each site within 400 x 1200 m areas for representing the coarse-scale within-site heterogeneity. Fine-scale compositional heterogeneity of vegetation within stands was sampled by recording the presence of species along 52 m long circular belt transects of 1040 units of 5 cm x 5 cm contiguous microquadrats. This sampling design enabled us to study the patterns of species combinations at a wide range of scales. The highest variability of plant species combinations appeared at very fine scales, between 10 cm and 25 cm. Differences in beta diversity along the gradient were scale-dependent. We found a decreasing trend of beta diversity with increasing aridity at fine scale, and on the contrary, an increasing trend at landscape scale. We conclude that the major trend of the vegetation differentiation due to aridity is the decrease of compositional variability at fine-scale accompanied by a coarse-scale diversification.

  6. Identification of optimum outfall location for desalination plant in the coastal waters off Tuticorin, India

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; NaveenKumar, K.R.; Muraleedharan, K.R.

    Behaviour of the dilution characteristics of the coastal waters off Tuticorin is presented in the background of setting up of a desalination plant. Simulations of dispersion and spreading of the proposed discharges has been carried out. Scenarios...

  7. In Silico Identification, Phylogenetic and Bioinformatic Analysis of Argonaute Genes in Plants

    Directory of Open Access Journals (Sweden)

    Khaled Mirzaei

    2014-01-01

    Full Text Available Argonaute protein family is the key players in pathways of gene silencing and small regulatory RNAs in different organisms. Argonaute proteins can bind small noncoding RNAs and control protein synthesis, affect messenger RNA stability, and even participate in the production of new forms of small RNAs. The aim of this study was to characterize and perform bioinformatic analysis of Argonaute proteins in 32 plant species that their genome was sequenced. A total of 437 Argonaute genes were identified and were analyzed based on lengths, gene structure, and protein structure. Results showed that Argonaute proteins were highly conserved across plant kingdom. Phylogenic analysis divided plant Argonautes into three classes. Argonaute proteins have three conserved domains PAZ, MID and PIWI. In addition to three conserved domains namely, PAZ, MID, and PIWI, we identified few more domains in AGO of some plant species. Expression profile analysis of Argonaute proteins showed that expression of these genes varies in most of tissues, which means that these proteins are involved in regulation of most pathways of the plant system. Numbers of alternative transcripts of Argonaute genes were highly variable among the plants. A thorough analysis of large number of putative Argonaute genes revealed several interesting aspects associated with this protein and brought novel information with promising usefulness for both basic and biotechnological applications.

  8. Radioecological sensitivity of permanent grasslands

    International Nuclear Information System (INIS)

    Besson, Benoit

    2009-01-01

    The project 'SENSIB' of the Institute for Radiological Protection and Nuclear Safety (IRSN) aims at characterizing and classifying parameters with significant impact on the transfer of radioactive contaminants in the environment. This thesis is focused on permanent grassland areas. Its objectives are the analysis of the activity variations of two artificial radionuclides ( 137 Cs and 90 Sr) in the chain from soil to dairy products as well as the categorization of ecological and anthropogenic parameters, which determine the sensitivity of the studied area. For this study, in situ sampling is carried out in 15 farms in 3 different French regions (Charente, Puy-de-Dome and Jura). The sampling sites are chosen according to their natural variations (geology, altitude and climate) and the soil types. Additionally to the radiologic measurements, geographic, soil and vegetation data as well as data concerning cattle-rearing and cheese manufacturing processes are gathered. From the soil to the grass vegetation, 137 Cs transfer factors vary between 3 x 10-3 and 148 x 10-3 Bq kg-1 (dry weight) per Bq kg-1 (dry weight) (N = 73). Theses transfer factors are significantly higher in the Puy-de-Dome region than in the Jura region. The 137 Cs transfer factor from cattle feed to milk varies from 5.9 x 10-3 to 258 x 10-3 Bq kg-1 (fresh weight) per Bq kg-1 (dry weight) (N = 28). Statistically, it is higher in the Charente region. Finally, the 90 Sr transfer factor from milk to cheese ranges from 3.9 to 12.1. The studied site with the highest factor is the Jura (N = 25). The link between milk and dairy products is the stage with the most 137 Cs and 90 Sr transfers. A nonlinear approach based on a discretization method of the transfer factor with multiple comparison tests admits a classification of the sensitivity factors from soil to grass vegetation. We can determine 20 factors interfering in the 137 Cs transfer into the vegetation, for instance, the clay rate of the soils or a marker

  9. Sustaining the grassland sea: Regional perspectives on identifying, protecting and restoring the Sky Island region's most intact grassland valley landscapes

    Science.gov (United States)

    Gitanjali S. Bodner; Peter Warren; David Gori; Karla Sartor; Steven Bassett

    2013-01-01

    Grasslands of the Sky Islands region once covered over 13 million acres in southeastern Arizona and adjacent portions of New Mexico, Sonora, and Chihuahua. Attempts to evaluate current ecological conditions suggest that approximately two thirds of these remain as intact or restorable grassland habitat. These grasslands provide watershed services such as flood control...

  10. Developing a Vital Area Identification in Nuclear Power Plants Using PSA Results

    International Nuclear Information System (INIS)

    Kim, Kilyoo; Jung, Woosik; Yang, Juneon

    2008-01-01

    After 9/11, a physical protection and vital area identification (VAI) became important. In the well known VAI methodology, fault trees (FTs) to mitigate the initiating events caused by sabotage or terror should be prepared for the VAI. The KAERI VAI method is to develop FTs by using Probabilistic Safety Assessment (PSA) and Risk Informed In-service Inspection (RI-ISI) results. In this paper, how to develop a VAI model by using PSA and RI-ISI results is described

  11. Identification of medicinal plant Schisandra chinensis using a potential DNA barcode ITS2

    Directory of Open Access Journals (Sweden)

    Xian-kuan Li

    2013-12-01

    Full Text Available To test whether the internal transcribed spacer 2 (ITS2 region is an effective marker for using in authenticating of the Schisandra chinensis at the species and population levels, separately. And the results showed that the wild populations had higher percentage of individuals that had substitution of C→A at site 86-bp than the cultivated populations. At sites 10-bp, 37-bp, 42-bp and 235-bp, these bases of the Schisandra sphenanthera samples differed from that of S. chinensis. Two species showed higher levels of inter-specific divergence than intra-specific divergence within ITS2 sequences. However, 24 populations did not demonstrate much difference as inter-specific and intra-specific divergences were concerned. Both S. chinensis and S. sphenanthera showed monophyly at species level, yet the samples of different populations shown polyphyly at population level. ITS2 performed well when using BLAST1 method. ITS2 obtained 100% identification success rates at the species level for S. chinensis, with no ambiguous identification at the genus level for ITS2 alone. The ITS2 region could be used to identify S. chinensis and S. sphenanthera in the “Chinese Pharmacopoeia”. And it could also correctly distinguish 100% of species and 100% of genera from the 193 sequences of S. chinensis. Hence, the ITS2 is a powerful and efficient tool for species identification of S. chinensis.

  12. From local checklists to online identification portals: a case study on vascular plants.

    Science.gov (United States)

    Martellos, Stefano; Nimis, Pier Luigi

    2015-01-01

    Checklists, the result of time-consuming exploration and painstaking bibliographic research, can be easily converted into online databases, which have the advantage of being updatable online in real time, and of reaching a much wider audience. However, thousands of local checklists (Natural Parks, protected areas, etc.) are still available on paper only, and most of those published online appear as dry lists of latin names, which strongly reduces their outreach for a wider audience. The University of Trieste has recently started the publication of several local checklists in a way that may be more appealing for the general public, by linking species' names to archives of digital resources, and especially to digital identification tools produced by software FRIDA (FRiendly IDentificAtion). The query interfaces were developed on the basis of feedback from a wide range of users. The result is no longer a simple list of names accessible on the Web, but a veritable multimedial, interactive portal to the biodiversity of a given area. This paper provides an example of how relevant added value can be given to local lists of taxa by embedding them in a complex system of biodiversity-related resources, making them usable for a much wider audience than a restricted circle of specialists, as testified by the almost 1.000.000 unique visitors reached in 2014. A critical mass of digital resources is also put at disposal of the scientific community by releasing them under a Creative Commons license.

  13. Grasslands feeling the heat: The effects of elevated temperatures on a subtropical grassland

    Directory of Open Access Journals (Sweden)

    Rowan D. Buhrmann

    2016-12-01

    Conclusions: OTCs can simulate realistic increases of air temperature in subtropical grasslands. Graminoids and shrubs appear to benefit from elevated temperatures whilst forbs decrease in abundance, possibly through competition and/or direct physiological effects.

  14. Identification of the impacts of maintenance and testing upon the safety of LWR power plants. Final report

    International Nuclear Information System (INIS)

    Husseiny, A.A.; Sabri, Z.A.; Turnage, J.J.

    1980-04-01

    The present study was designed to identify the impact of maintenance and testing (M and T) upon the safety of LWR power plants. The study involved data extraction from various sources reporting safety-related and operation-related nuclear power plant experience. Primary sources reviewed, including Licensee Event Reports (LER's) submitted to the NRC, revealed that only ten percent of events reported could be identified as M and T problems. The collected data were collated in a manner that would allow identification of principal types of problems which are associated with the performance of M and T tasks in LWR power plants. Frequencies of occurrence of events and their general endemic nature were analyzed using data clustering and pattern recognition techniques, as well as chi-square analyses for sparse contingency tables. The results of these analyses identified seven major categories of M and T error modes which were related to individual facilities and reactor type. Data review indicated that few M and T problems were directly related to procedural inadequacies, with the majority of events being attributable to human error

  15. Assessing the Impact of Spectral Resolution on Classification of Lowland Native Grassland Communities Based on Field Spectroscopy in Tasmania, Australia

    Directory of Open Access Journals (Sweden)

    Bethany Melville

    2018-02-01

    Full Text Available This paper presents a case study for the analysis of endangered lowland native grassland communities in the Tasmanian Midlands region using field spectroscopy and spectral convolution techniques. The aim of the study was to determine whether there was significant improvement in classification accuracy for lowland native grasslands and other vegetation communities based on hyperspectral resolution datasets over multispectral equivalents. A spectral dataset was collected using an ASD Handheld-2 spectroradiometer at Tunbridge Township Lagoon. The study then employed a k-fold cross-validation approach for repeated classification of a full hyperspectral dataset, a reduced hyperspectral dataset, and two convoluted multispectral datasets. Classification was performed on each of the four datasets a total of 30 times, based on two different class configurations. The classes analysed were Themeda triandra grassland, Danthonia/Poa grassland, Wilsonia rotundifolia/Selliera radicans, saltpan, and a simplified C3 vegetation class. The results of the classifications were then tested for statistically significant differences using ANOVA and Tukey’s post-hoc comparisons. The results of the study indicated that hyperspectral resolution provides small but statistically significant increases in classification accuracy for Themeda and Danthonia grasslands. For other classes, differences in classification accuracy for all datasets were not statistically significant. The results obtained here indicate that there is some potential for enhanced detection of major lowland native grassland community types using hyperspectral resolution datasets, and that future analysis should prioritise good performance in these classes over others. This study presents a method for identification of optimal spectral resolution across multiple datasets, and constitutes an important case study for lowland native grassland mapping in Tasmania.

  16. Seismic margin reviews of nuclear power plants: Identification of important functions and systems

    International Nuclear Information System (INIS)

    Prassinos, P.G.; Moore, D.L.; Amico, P.J.

    1987-01-01

    The results from the review of the seven utility-sponsored seismic PRAs plus the Zion SSMRP have been used to develop some insights regarding the importance of various systems and functions to seismic margins. By taking this information and combining it with the fragility insights we can develop some functional/systemic screening guideline for margin studies. This screening approach will greatly reduce the scope of the analysis. It is possible only to come to conclusions regarding the importance of plant systems and safety functions for PWRs, for which six plants were studied. For PWRs, it is possible to categorize plant safety functions as belonging to one of two groups, one of which is important to the assessment of seismic margins and one of which is not. The important functional group involves only two functions that must be considered for estimating seismic margin. These two functions are shutting down the nuclear reaction and providing cooling to the reactor core in the time period immediately following the seismic event (that is, the injection phase or pre-residual heat removal time period). It is possible to reasonably estimate the seismic margin of the plant by performing a study only involving the analysis of the plant systems and structure which are required in order to perform the two functions. Such analysis must include an assessment of a complete set of seismic initiating events. (orig./HP)

  17. Identification of the plants use as natural herbal shampoo in Manipur.

    Science.gov (United States)

    Singh, S R; Phurailatpam, A K; Senjam, P

    2014-01-01

    A field survey was conducted in the year, 2011 - 12 in Imphal valley of Manipur, on the use of herbs as ingredient sources for the preparation of traditional natural herbal shampoo referred to as 'Chinghi', by Meitei community. Methodological field survey and personal interview of local people aged between 30-70 years of both sexes using standard questionnaires were carried out to collect information on the plants use in the herbal shampoo preparation. The survey revealed the therapeutic application of 35 plant species representing 28 genera and 18 families available in the Imphal valley. Tree species contributed immensely, yielding 38%, while herbs 32%, shrubs 27%, and climbing shrubs 3%, respectively being the record of the total number of plants used as ingredient in herbal shampoo preparation. These natural shampoos are used for a wide range of common hair care like anti-ageing of the hair, blackness, shininess and smoothness of the hair. It is prepared from young leaves and tender stalk of shoot of trees or shrubs, or whole plant of the herbs and fresh fruits boiled with local sticky rice water locally called 'Chinghi'. Fermented lime peel is also used as a herbal shampoo. The study shows details of their scientific, common, and local names, including their family, parts used, habit of the plants, and the benefit to the hair health as a whole.

  18. Identification of octanal as plant growth inhibitory volatile compound released from Heracleum sosnowskyi fruit.

    Science.gov (United States)

    Mishyna, Maryia; Laman, Nikolai; Prokhorov, Valery; Maninang, John Solomon; Fujii, Yoshiharu

    2015-05-01

    Heracleum sosnowskyi Manden of the Apiaceae family is a malignant invasive plant in Eastern Europe, Belarus and Russia. The species is known for its prolific seed production, which has been linked to the plant's invasive success. The fruit also has a strong aroma, but the contribution of the fruit's volatile constituent to out-compete neighboring plants has not been fully established. In this study, fruit volatiles of H. sosnowskyi and conspecifics (i.e. H. asperum, H. lescovii, H. dissectum, H. hirtum) were identified by headspace gas chromatography-mass spectrometry (HS-GC-MS). Octyl acetate, octanol, octanal, hexyl isobutyrate, and hexyl-2-methyl butyrate were found to be the principal volatiles. Using authentic standards, the growth-inhibitory property of the individual compounds was assayed by the novel Cotton swab method. Assay results with lettuce (Lactuca sativa) showed that octanal strongly inhibited seed germination and radicle elongation of seedlings. The results suggest that octanal may be the main contributor to the allelopathic activity of H. sosnowksyi fruits. Furthermore, the mixture of fruit volatiles from the invasive H. sosnowskyi more strongly delayed lettuce seedling elongation than the volatiles from fruits of the non-invasive H. asperum, H. lescovii, H. dissectum and H. hirtum. Thus, the present study is the first to demonstrate the possible involvement of fruit volatiles of Heracleum species in plant-plant interaction.

  19. Automated Identification of Northern Leaf Blight-Infected Maize Plants from Field Imagery Using Deep Learning.

    Science.gov (United States)

    DeChant, Chad; Wiesner-Hanks, Tyr; Chen, Siyuan; Stewart, Ethan L; Yosinski, Jason; Gore, Michael A; Nelson, Rebecca J; Lipson, Hod

    2017-11-01

    Northern leaf blight (NLB) can cause severe yield loss in maize; however, scouting large areas to accurately diagnose the disease is time consuming and difficult. We demonstrate a system capable of automatically identifying NLB lesions in field-acquired images of maize plants with high reliability. This approach uses a computational pipeline of convolutional neural networks (CNNs) that addresses the challenges of limited data and the myriad irregularities that appear in images of field-grown plants. Several CNNs were trained to classify small regions of images as containing NLB lesions or not; their predictions were combined into separate heat maps, then fed into a final CNN trained to classify the entire image as containing diseased plants or not. The system achieved 96.7% accuracy on test set images not used in training. We suggest that such systems mounted on aerial- or ground-based vehicles can help in automated high-throughput plant phenotyping, precision breeding for disease resistance, and reduced pesticide use through targeted application across a variety of plant and disease categories.

  20. Evaluation of Rgb-Based Vegetation Indices from Uav Imagery to Estimate Forage Yield in Grassland

    Science.gov (United States)

    Lussem, U.; Bolten, A.; Gnyp, M. L.; Jasper, J.; Bareth, G.

    2018-04-01

    Monitoring forage yield throughout the growing season is of key importance to support management decisions on grasslands/pastures. Especially on intensely managed grasslands, where nitrogen fertilizer and/or manure are applied regularly, precision agriculture applications are beneficial to support sustainable, site-specific management decisions on fertilizer treatment, grazing management and yield forecasting to mitigate potential negative impacts. To support these management decisions, timely and accurate information is needed on plant parameters (e.g. forage yield) with a high spatial and temporal resolution. However, in highly heterogeneous plant communities such as grasslands, assessing their in-field variability non-destructively to determine e.g. adequate fertilizer application still remains challenging. Especially biomass/yield estimation, as an important parameter in assessing grassland quality and quantity, is rather laborious. Forage yield (dry or fresh matter) is mostly measured manually with rising plate meters (RPM) or ultrasonic sensors (handheld or mounted on vehicles). Thus the in-field variability cannot be assessed for the entire field or only with potential disturbances. Using unmanned aerial vehicles (UAV) equipped with consumer grade RGB cameras in-field variability can be assessed by computing RGB-based vegetation indices. In this contribution we want to test and evaluate the robustness of RGB-based vegetation indices to estimate dry matter forage yield on a recently established experimental grassland site in Germany. Furthermore, the RGB-based VIs are compared to indices computed from the Yara N-Sensor. The results show a good correlation of forage yield with RGB-based VIs such as the NGRDI with R2 values of 0.62.

  1. Arbuscular mycorrhiza fungi mediate soil respiration response to climate change in California grasslands

    Science.gov (United States)

    Estruch, Carme; Mcfarland, Jack; Haw, Monica P.; Schulz, Marjorie S.; Pugnaire, Francisco I.; Waldrop, Mark P.

    2017-04-01

    California grasslands store ca. 100 Tg of soil organic carbon (SOC) and almost 40% of those ecosystems are prone to land use changes. The fate of these carbon pools will largely depend on how the main components of soil respiration - i.e., roots, mycorrhiza, and 'bulk soil' communities- respond to such changes. In order to determine the sensitivity to environmental drivers we set up an experiment to address the effect of plant community composition, soil age and warming on soil respiration rate during the 2014-2015 winter. We tested differences among microbial, fungal and root respiration using an exclusion technique to assess the effect of plant community (open grasslands vs oak woodland) in two field sites differing in soil properties as nutrient content, related to geologic soil age (92 and 137 kyr). We also used open top chambers (OTC) to simulate global change effects on grasslands. Our results showed that arbuscular mycorrhizal fungi were the main drivers of differences recorded between soils of different age, and that those differences were linked to nutrient availability. Bulk soil respiration was more sensitive to environmental variation than mycorrhizal or root respiration, indicating that the presence of mycorrhizae and roots can regulate the capacity of CO2 emission to the atmosphere. Soil age affected CO2 flux from grasslands but not under oak canopies, likely due to the high concentration of SOM in oak canopies which moderated any affect of soil mineralogy on nutrient availability. Overall our study shows that the ability of grasslands to mitigate CO2 emissions depends on interactions between vegetation and their rhizosphere on soil microbial communities.

  2. Effects of water and nitrogen addition on species turnover in temperate grasslands in northern China.

    Directory of Open Access Journals (Sweden)

    Zhuwen Xu

    Full Text Available Global nitrogen (N deposition and climate change have been identified as two of the most important causes of current plant diversity loss. However, temporal patterns of species turnover underlying diversity changes in response to changing precipitation regimes and atmospheric N deposition have received inadequate attention. We carried out a manipulation experiment in a steppe and an old-field in North China from 2005 to 2009, to test the hypothesis that water addition enhances plant species richness through increase in the rate of species gain and decrease in the rate of species loss, while N addition has opposite effects on species changes. Our results showed that water addition increased the rate of species gain in both the steppe and the old field but decreased the rates of species loss and turnover in the old field. In contrast, N addition increased the rates of species loss and turnover in the steppe but decreased the rate of species gain in the old field. The rate of species change was greater in the old field than in the steppe. Water interacted with N to affect species richness and species turnover, indicating that the impacts of N on semi-arid grasslands were largely mediated by water availability. The temporal stability of communities was negatively correlated with rates of species loss and turnover, suggesting that water addition might enhance, but N addition would reduce the compositional stability of grasslands. Experimental results support our initial hypothesis and demonstrate that water and N availabilities differed in the effects on rate of species change in the temperate grasslands, and these effects also depend on grassland types and/or land-use history. Species gain and loss together contribute to the dynamic change of species richness in semi-arid grasslands under future climate change.

  3. Wetland Plant Guide for Assessing Habitat Impacts of Real-Time Salinity Management

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, Nigel W.T.; Feldmann, Sara A.

    2004-10-15

    This wetland plant guide was developed to aid moist soil plant identification and to assist in the mapping of waterfowl and shorebird habitat in the Grassland Water District and surrounding wetland areas. The motivation for this habitat mapping project was a concern that real-time salinity management of wetland drainage might have long-term consequences for wildfowl habitat health--changes in wetland drawdown schedules might, over the long term, lead to increased soil salinity and other conditions unfavorable to propagation of the most desirable moist soil plants. Hence, the implementation of a program to monitor annual changes in the most common moist soil plants might serve as an index of habitat health and sustainability. Our review of the current scientific and popular literature failed to identify a good, comprehensive field guide that could be used to calibrate and verify high resolution remote sensing imagery, that we had started to use to develop maps of wetland moist soil plants in the Grassland Water District. Since completing the guide it has been used to conduct ground truthing field surveys using the California Native Plant Society methodology in 2004. Results of this survey and a previous wetland plant survey in 2003 are published in a companion LBNL publication summarizing 4 years of fieldwork to advance the science of real-time wetland salinity management.

  4. Identification and Control of Nutrient Removing Processes in Wastewater Treatment Plants

    DEFF Research Database (Denmark)

    Nielsen, Marinus K.; Madsen, Henrik; Carstensen, Niels Jacob

    1994-01-01

    the possibility of using statistical methods for identifying dynamical models for the biological processes. These models can then be used for simulating various control strategies and the parameters of the controllers can be found by off-line optimization. Simulation studies have shown that considerable savings......Today the use of on-line control for wastewater treatment plants is very low. A main reason is the lack of quality of the data, and the fact that more sophisticated control strategies must be based on a model of the dynamics of the biological processes. This paper discusses the historical reasons...... for the limited use of modern control strategies for wastewater treatment plants. Today, however, on-line nutrient sensors are more reliable. In the present context the use of on-line monitored values of ammonia, nitrate and phosphate from a full scale plant are used as the background for discussing...

  5. On the stability of mixed grasslands

    NARCIS (Netherlands)

    Schulte, R.P.O.

    2001-01-01

    Recent years have seen a renewed interest in the use of white clover (Trifolium repens) in grasslands, as a more sustainable alternative to fertiliser nitrogen inputs. However, mixtures of grasses and white clover have frequently been associated with unstable and hence unreliable herbage

  6. Purpose and Need for a Grassland Assessment

    Science.gov (United States)

    Deborah M. Finch; Cathy W. Dahms

    2004-01-01

    This report is volume 1 of an ecological assessment of grassland ecosystems in the Southwestern United States, and it is one of a series of planned publications addressing major ecosystems of the Southwest. The first assessment, General Technical Report RM-GTR- 295, An Assessment of Forest Ecosystem Health in the Southwest (by Dahms and Geils, technical editors,...

  7. A plant-based chemical genomics screen for the identification of flowering inducers.

    Science.gov (United States)

    Fiers, Martijn; Hoogenboom, Jorin; Brunazzi, Alice; Wennekes, Tom; Angenent, Gerco C; Immink, Richard G H

    2017-01-01

    Floral timing is a carefully regulated process, in which the plant determines the optimal moment to switch from the vegetative to reproductive phase. While there are numerous genes known that control flowering time, little information is available on chemical compounds that are able to influence this process. We aimed to discover novel compounds that are able to induce flowering in the model plant Arabidopsis. For this purpose we developed a plant-based screening platform that can be used in a chemical genomics study. Here we describe the set-up of the screening platform and various issues and pitfalls that need to be addressed in order to perform a chemical genomics screening on Arabidopsis plantlets. We describe the choice for a molecular marker, in combination with a sensitive reporter that's active in plants and is sufficiently sensitive for detection. In this particular screen, the firefly Luciferase marker was used, fused to the regulatory sequences of the floral meristem identity gene APETALA1 (AP1) , which is an early marker for flowering. Using this screening platform almost 9000 compounds were screened, in triplicate, in 96-well plates at a concentration of 25 µM. One of the identified potential flowering inducing compounds was studied in more detail and named Flowering1 (F1). F1 turned out to be an analogue of the plant hormone Salicylic acid (SA) and appeared to be more potent than SA in the induction of flowering. The effect could be confirmed by watering Arabidopsis plants with SA or F1, in which F1 gave a significant reduction in time to flowering in comparison to SA treatment or the control. In this study a chemical genomics screening platform was developed to discover compounds that can induce flowering in Arabidopsis. This platform was used successfully, to identify a compound that can speed-up flowering in Arabidopsis.

  8. Cover Image Identification of Plant Species for Crop Pollinator Habitat Enhancement in the Northern Prairies

    Directory of Open Access Journals (Sweden)

    Diana Bizecki Robson

    2014-09-01

    Full Text Available Wild pollinators have a positive impact on the productivity of insect-pollinated crops. Consequently, landowners are being encouraged to maintain and grow wildflower patches to provide habitat for important pollinators. Research on plant-pollinator interaction matrices indicates that a small number of “core” plants provide a disproportionately high amount of pollen and nectar to insects. This matrix data can be used to help design wildflower plantings that provide optimal resources for desirable pollinators. Existing interaction matrices from three tall grass prairie preserves in the northern prairies were used to identify core plant species that are visited by wild pollinators of a common insect-pollinated crop, namely canola (Brassica napus L.. The wildflower preferences of each insect taxon were determined using quantitative insect visitation and floral abundance data. Phenology data were used to calculate the degree of floral synchrony between the wildflowers and canola. Using this information I ranked the 41 wildflowers that share insect visitors with canola according to how useful they are for providing pollinators with forage before and after canola flowers. The top five species were smooth blue aster (Symphyotrichum laeve (L. A. & D. Löve, stiff goldenrod (Solidago rigida L., wild bergamot (Monarda fistulosa L., purple prairie-clover (Dalea purpurea Vent. and Lindley’s aster (Symphyotrichum ciliolatum (Lindl. A. & D. Löve. By identifying the most important wild insects for crop pollination, and determining when there will be “pollen and nectar gaps”, appropriate plant species can be selected for companion plantings to increase pollinator populations and crop production.

  9. [Spatiotemporal characteristics of MODIS NDVI in Hulunber Grassland].

    Science.gov (United States)

    Zhang, Hong-Bin; Yang, Gui-Xia; Wu, Wen-Bin; Li, Gang; Chen, Bao-Rui; Xin, Xiao-Ping

    2009-11-01

    Time-series MODIS NDVI datasets from 2000 to 2008 were used to study the spatial change trend, fluctuation degree, and occurrence time of the annual NDVImax of four typical grassland types, i.e., lowland meadow, temperate steppe, temperate meadow steppe, and upland meadow, in Hulunber Grassland. In 2000-2008, the vegetation in Hulunber Grassland presented an obvious deterioration trend. The mean annual NDVImax of the four grassland types had a great fluctuation, especially in temperate steppe where the maximum change in the mean value of annual NDVImax approximated to 50%. As for the area change of different grade grasslands, the areas with NDVImax between 0.4 and 1 accounted for about 91% of the total grassland area, which suggested the good vegetation coverage in the Grassland. However, though the areas with NDVImax values in (0.4, 0.8) showed an increasing trend, the areas with NDVImax values in (0.2, 0.4) and (0.8, 1) decreased greatly in the study period. Overall, the deteriorating grassland took up about 66.25% of the total area, and the restoring grassland took the rest. There was about 62.85% of the grassland whose NDVImax occurred between the 193rd day and the 225th day in each year, indicating that this period was the most important vegetation growth season in Hulunber Grassland.

  10. Identification of Fabaceae plants using the DNA barcode matK.

    Science.gov (United States)

    Gao, Ting; Sun, Zhiying; Yao, Hui; Song, Jingyuan; Zhu, Yingjie; Ma, Xinye; Chen, Shilin

    2011-01-01

    In this study, we tested the applicability of the core DNA barcode MATK for identifying species within the Fabaceae family. Based on an evaluation of genetic variation, DNA barcoding gaps, and species discrimination power, MATK is a useful barcode for Fabaceae species. Of 1355 plant samples collected from 1079 species belonging to 409 diverse genera, MATK precisely identified approximately 80 % and 96 % of them at the species and genus levels, respectively. Therefore, our research indicates that the MATK region is a valuable marker for plant species within Fabaceae. © Georg Thieme Verlag KG Stuttgart · New York.

  11. Bio aerosol Generation at wastewater treatment plants: Identification of main bio aerosols sources

    International Nuclear Information System (INIS)

    Sanchez Monedero, M. A.; Aguilar, M. I.; Fenoll, R.; Roig, A.

    2009-01-01

    Typical operations taking place at wastewater treatment plants, especially those involving aeration and mechanical agitation of raw wastewater, represent one of the main sources of bio aerosols that, if inhaled, could pose a biologic hazard to site workers and local residents. Six different wastewater treatment plants from southeast Spain were monitories in order to identify the main bio aerosol sources and to evaluate the airborne microorganisms levels to which workers may be exposed to. Air samples were taken from selected locations by using a single stage impactor. (Author)

  12. Aggregation and C dynamics along an elevation gradient in carbonate-containing grassland soils of the Alps

    Science.gov (United States)

    Garcia-Franco, Noelia; Wiesmeier, Martin; Kiese, Ralf; Dannenmann, Michael; Wolf, Benjamin; Zistl-Schlingmann, Marcus; Kögel-Knabner, Ingrid

    2017-04-01

    C sequestration in mountainous grassland soils is regulated by physical, chemical and biological soil process. An improved knowledge of the relationship between these stabilization mechanisms is decisive to recommend the best management practices for climate change mitigation. In this regard, the identification of a successful indicator of soil structural improvement and C sequestration in mountainous grassland soils is necessary. Alpine and pre-alpine grassland soils in Bavaria represent a good example for mountainous grassland soils faced with climate change. We sampled grassland soils of the northern limestone alps in Bavaria along an elevation gradient from 550 to 1300 m above sea level. We analyzed C dynamics by a comparative analysis of the distribution of C according to aggregate size classes: large-macroaggregates (> 2000 µm), small-macroaggregates (250-2000 µm), microaggregates (63-250 µm), silt plus clay particles (soil. Our preliminary results showed higher C content and changed water-stable aggregate distribution in the high elevation sites compared to lower elevations. Magnesium carbonate seem to play an important role in stabilizing macroaggregates formed from fresh OM. In addition, the isolation of occluded microaggregates within macroaggregates will help us to improve our understanding on the effects of climate change on soil structure and on the sensitivity of different C stabilization mechanisms present in mountainous soils.

  13. Application of neural networks to connectional expert system for identification of transients in nuclear power plants

    International Nuclear Information System (INIS)

    Cheon, Se Woo; Kim, Wan Joo; Chang, Soon Heung; Roh, Myung Sub

    1991-01-01

    The Back-propagation Neural Network (BPN) algorithm is applied to connectionist expert system for the identification of BWR transients. Several powerful features of neural network-based expert systems over traditional rule-based expert systems are described. The general mapping capability of the neural networks enables to identify transients easily. A number of case studies were performed with emphasis on the applicability of the neural networks to the diagnostic domain. It is revealed that the BPN algorithm can identify transients properly, even when incomplete or untrained symptoms are given. It is also shown that multiple transients are easily identified

  14. An approach using quantum ant colony optimization applied to the problem of identification of nuclear power plant transients

    International Nuclear Information System (INIS)

    Silva, Marcio H.; Schirru, Roberto; Medeiros, Jose A.C.C.

    2009-01-01

    Using concepts and principles of the quantum computation, as the quantum bit and superposition of states, coupled with the biological metaphor of a colony of ants, used in the Ant Colony Optimization algorithm (ACO), Wang et al developed the Quantum Ant Colony Optimization (QACO). In this paper we present a modification of the algorithm proposed by Wang et al. While the original QACO was used just for simple benchmarks functions with, at the most, two dimensions, QACO A lfa was developed for application where the original QACO, due to its tendency to converge prematurely, does not obtain good results, as in complex multidimensional functions. Furthermore, to evaluate its behavior, both algorithms are applied to the real problem of identification of accidents in PWR nuclear power plants. (author)

  15. The identification of cutin synthase: formation of the plant polyester cutin

    DEFF Research Database (Denmark)

    Yeats, Trevor H.; Martin, Laetitia B. B.; Viart, Helene Marie-France

    2012-01-01

    A hydrophobic cuticle consisting of waxes and the polyester cutin covers the aerial epidermis of all land plants, providing essential protection from desiccation and other stresses. We have determined the enzymatic basis of cutin polymerization through characterization of a tomato extracellular...

  16. Identification of the mosquito biting deterrent constituents from the Indian folk remedy plant Jatropha curcas

    Science.gov (United States)

    An investigation of the Indian folk remedy plant, Jatropha curcas, was performed to specifically identify the constituents responsible for the mosquito biting deterrent activity of the oil as a whole. Jatropha curcas seed oil is burned in oil lamps in India and part of Africa to repel biting insect...

  17. Seed Endophyte Microbiome of Crotalaria pumila Unpeeled: Identification of Plant-Beneficial Methylobacteria.

    Science.gov (United States)

    Sánchez-López, Ariadna S; Pintelon, Isabel; Stevens, Vincent; Imperato, Valeria; Timmermans, Jean-Pierre; González-Chávez, Carmen; Carrillo-González, Rogelio; Van Hamme, Jonathan; Vangronsveld, Jaco; Thijs, Sofie

    2018-01-19

    Metal contaminated soils are increasing worldwide. Metal-tolerant plants growing on metalliferous soils are fascinating genetic and microbial resources. Seeds can vertically transmit endophytic microorganisms that can assist next generations to cope with environmental stresses, through yet poorly understood mechanisms. The aims of this study were to identify the core seed endophyte microbiome of the pioneer metallophyte Crotalaria pumila throughout three generations, and to better understand the plant colonisation of the seed endophyte Methylobacterium sp. Cp3. Strain Cp3 was detected in C. pumila seeds across three successive generations and showed the most dominant community member. When inoculated in the soil at the time of flowering, strain Cp3 migrated from soil to seeds. Using confocal microscopy, Cp3-mCherry was demonstrated to colonise the root cortex cells and xylem vessels of the stem under metal stress. Moreover, strain Cp3 showed genetic and in planta potential to promote seed germination and seedling development. We revealed, for the first time, that the seed microbiome of a pioneer plant growing in its natural environment, and the colonisation behaviour of an important plant growth promoting systemic seed endophyte. Future characterization of seed microbiota will lead to a better understanding of their functional contribution and the potential use for seed-fortification applications.

  18. Identification of the protective effects of traditional medicinal plants against SDS-induced Drosophila gut damage.

    Science.gov (United States)

    Zhou, Yang; Liu, Zonglin; Chen, Yuchen; Jin, Li Hua

    2016-10-01

    Traditional medicinal plants are widely used as immunomodulatory medicines that help improve health. A total of 50 different plants used for the treatment of toxicity were screened for their in vivo protective effects. Flies were fed a standard cornmeal-yeast medium (control group) or the standard medium containing medicinal plant extracts (experimental groups). Assessment of the survival rate was performed by feeding flies with toxic compounds. Gut epithelial cells were analyzed for cell proliferation and death by green fluorescent protein antibodies and 7-aminoactinomycin D staining under the microscope. The expression of antimicrobial peptides (AMPs) was evaluated by the quantitative polymerase chain reaction and the results revealed that after feeding the flies with toxic compounds, aqueous extracts from Codonopsis pilosula (Franch.) Nannf ( C. pilosula ), Saussurea lappa (Decne.) C.B.Clarke ( S. lappa ), Imperata cylindrica Beauv.var. major (Nees) C.E. Hubb. ( I. cylindrical var. major ) and Melia toosendan Sied. Et Zucc. ( M.toosendan ) increased the fly survival rate, reduced epithelial cell death and improved gut morphology. In addition, C. pilosula extracts induced the antimicrobial peptide levels (Dpt and Mtk) following treatment with sodium dodecyl sulfate (SDS). However, these extracts were not observed to increase SDS-induced cell proliferation in vivo . These results indicate that there are strong protective effects in extracts of C. pilosula , S. lappa , I. cylindrical var. major and M. toosendan on Drosophila intestinal cells among 50 medicinal plants.

  19. A plant-based chemical genomics screen for the identification of flowering inducers

    NARCIS (Netherlands)

    Fiers, Martijn; Hoogenboom, Jorin; Brunazzi, Alice; Wennekes, Tom; Angenent, Gerco C; Immink, Richard G H

    2017-01-01

    BACKGROUND: Floral timing is a carefully regulated process, in which the plant determines the optimal moment to switch from the vegetative to reproductive phase. While there are numerous genes known that control flowering time, little information is available on chemical compounds that are able to

  20. Identification of a new class of lipid droplet-associated proteins in plants

    Science.gov (United States)

    Lipid droplets in plants (also known as oil bodies, lipid bodies or oleosomes) are well characterized in seeds, and oleosins, the major proteins associated with their surface, were shown to be important for stabilizing lipid droplets during seed desiccation and rehydration. However, lipid droplets ...

  1. Uncertainty identification for robust control using a nuclear power plant model

    International Nuclear Information System (INIS)

    Power, M.; Edwards, R.M.

    1995-01-01

    An on-line technique which identifies the uncertainty between a lower order and a higher order nuclear power plant model is presented. The uncertainty identifier produces a hard upper bound in H ∞ on the additive uncertainty. This additive uncertainty description can be used for the design of H infinity or μ-synthesis controllers

  2. Seed Endophyte Microbiome of Crotalaria pumila Unpeeled: Identification of Plant-Beneficial Methylobacteria

    Directory of Open Access Journals (Sweden)

    Ariadna S. Sánchez-López

    2018-01-01

    Full Text Available Metal contaminated soils are increasing worldwide. Metal-tolerant plants growing on metalliferous soils are fascinating genetic and microbial resources. Seeds can vertically transmit endophytic microorganisms that can assist next generations to cope with environmental stresses, through yet poorly understood mechanisms. The aims of this study were to identify the core seed endophyte microbiome of the pioneer metallophyte Crotalaria pumila throughout three generations, and to better understand the plant colonisation of the seed endophyte Methylobacterium sp. Cp3. Strain Cp3 was detected in C. pumila seeds across three successive generations and showed the most dominant community member. When inoculated in the soil at the time of flowering, strain Cp3 migrated from soil to seeds. Using confocal microscopy, Cp3-mCherry was demonstrated to colonise the root cortex cells and xylem vessels of the stem under metal stress. Moreover, strain Cp3 showed genetic and in planta potential to promote seed germination and seedling development. We revealed, for the first time, that the seed microbiome of a pioneer plant growing in its natural environment, and the colonisation behaviour of an important plant growth promoting systemic seed endophyte. Future characterization of seed microbiota will lead to a better understanding of their functional contribution and the potential use for seed-fortification applications.

  3. Construction of a SSR-Based Genetic Map and Identification of QTLs for Catechins Content in Tea Plant (Camellia sinensis)

    Science.gov (United States)

    Ma, Chun-Lei; Wang, Xin-Chao; Jin, Ji-Qiang; Wang, Xue-Min; Chen, Liang

    2014-01-01

    Catechins are the most important bioactive compounds in tea, and have been demonstrated to possess a wide variety of pharmacological activities. To characterize quantitative trait loci (QTLs) for catechins content in the tender shoots of tea plant, we constructed a moderately saturated genetic map using 406 simple sequence repeat (SSR) markers, based on a pseudo-testcross population of 183 individuals derived from an intraspecific cross of two Camellia sinensis varieties with diverse catechins composition. The map consisted of fifteen linkage groups (LGs), corresponding to the haploid chromosome number of tea plant (2n = 2x = 30). The total map length was 1,143.5 cM, with an average locus spacing of 2.9 cM. A total of 25 QTLs associated with catechins content were identified over two measurement years. Of these, nine stable QTLs were validated across years, and clustered into four main chromosome regions on LG03, LG11, LG12 and LG15. The population variability explained by each QTL was predominantly at moderate-to-high levels and ranged from 2.4% to 71.0%, with an average of 17.7%. The total number of QTL for each trait varied from four to eight, while the total population variability explained by all QTLs for a trait ranged between 38.4% and 79.7%. This is the first report on the identification of QTL for catechins content in tea plant. The results of this study provide a foundation for further cloning and functional characterization of catechin QTLs for utilization in improvement of tea plant. PMID:24676054

  4. Grassland/atmosphere response to changing climate: Coupling regional and local scales

    International Nuclear Information System (INIS)

    Coughenour, M.B.; Kittel, T.G.F.; Pielke, R.A.; Eastman, J.

    1993-10-01

    The objectives of the study were: to evaluate the response of grassland ecosystems to atmospheric change at regional and site scales, and to develop multiscaled modeling systems to relate ecological and atmospheric models with different spatial and temporal resolutions. A menu-driven shell was developed to facilitate use of models at different temporal scales and to facilitate exchange information between models at different temporal scales. A detailed ecosystem model predicted that C 3 temperate grasslands wig respond more strongly to elevated CO 2 than temperate C 4 grasslands in the short-term while a large positive N-PP response was predicted for a C 4 Kenyan grassland. Long-term climate change scenarios produced either decreases or increases in Colorado plant productivity (NPP) depending on rainfall, but uniform increases in N-PP were predicted in Kenya. Elevated CO 2 is likely to have little effect on ecosystem carbon storage in Colorado while it will increase carbon storage in Kenya. A synoptic climate classification processor (SCP) was developed to evaluate results of GCM climate sensitivity experiments. Roughly 80% agreement was achieved with manual classifications. Comparison of lx and 2xCO 2 GCM Simulations revealed relatively small differences

  5. Large Scale Screening of Ethnomedicinal Plants for Identification of Potential Antibacterial Compounds

    Directory of Open Access Journals (Sweden)

    Sujogya Kumar Panda

    2016-03-01

    Full Text Available The global burden of bacterial infections is very high and has been exacerbated by increasing resistance to multiple antibiotics. Antibiotic resistance leads to failed treatment of infections, which can ultimately lead to death. To overcome antibiotic resistance, it is necessary to identify new antibacterial agents. In this study, a total of 662 plant extracts (diverse parts from 222 plant species (82 families, 177 genera were screened for antibacterial activity using the agar cup plate method. The aqueous and methanolic extracts were prepared from diverse plant parts and screened against eight bacterial (two Gram-positive and six Gram-negative species, most of which are involved in common infections with multiple antibiotic resistance. The methanolic extracts of several plants were shown to have zones of inhibition ≥ 12 mm against both Gram-positive and Gram-negative bacteria. The minimum inhibitory concentration was calculated only with methanolic extracts of selected plants, those showed zone of inhibition ≥ 12 mm against both Gram-positive and Gram-negative bacteria. Several extracts had minimum inhibitory concentration ≤ 1 mg/mL. Specifically Adhatoda vasica, Ageratum conyzoides, Alangium salvifolium, Alpinia galanga, Andrographis paniculata, Anogeissus latifolia, Annona squamosa, A. reticulate, Azadirachta indica, Buchanania lanzan, Cassia fistula, Celastrus paniculatus, Centella asiatica, Clausena excavate, Cleome viscosa, Cleistanthus collinus, Clerodendrum indicum, Croton roxburghii, Diospyros melanoxylon, Eleutherine bulbosa, Erycibe paniculata, Eryngium foetidum, Garcinia cowa, Helicteres isora, Hemidesmus indicus, Holarrhena antidysenterica, Lannea coromandelica, Millettia extensa, Mimusops elengi, Nyctanthes arbor-tristis, Oroxylum indicum, Paederia foetida, Pterospermum acerifolium, Punica granatum, Semecarpus anacardium, Spondias pinnata, Terminalia alata and Vitex negundo were shown to have significant antimicrobial

  6. Large Scale Screening of Ethnomedicinal Plants for Identification of Potential Antibacterial Compounds.

    Science.gov (United States)

    Panda, Sujogya Kumar; Mohanta, Yugal Kishore; Padhi, Laxmipriya; Park, Young-Hwan; Mohanta, Tapan Kumar; Bae, Hanhong

    2016-03-14

    The global burden of bacterial infections is very high and has been exacerbated by increasing resistance to multiple antibiotics. Antibiotic resistance leads to failed treatment of infections, which can ultimately lead to death. To overcome antibiotic resistance, it is necessary to identify new antibacterial agents. In this study, a total of 662 plant extracts (diverse parts) from 222 plant species (82 families, 177 genera) were screened for antibacterial activity using the agar cup plate method. The aqueous and methanolic extracts were prepared from diverse plant parts and screened against eight bacterial (two Gram-positive and six Gram-negative) species, most of which are involved in common infections with multiple antibiotic resistance. The methanolic extracts of several plants were shown to have zones of inhibition ≥ 12 mm against both Gram-positive and Gram-negative bacteria. The minimum inhibitory concentration was calculated only with methanolic extracts of selected plants, those showed zone of inhibition ≥ 12 mm against both Gram-positive and Gram-negative bacteria. Several extracts had minimum inhibitory concentration ≤ 1 mg/mL. Specifically Adhatoda vasica, Ageratum conyzoides, Alangium salvifolium, Alpinia galanga, Andrographis paniculata, Anogeissus latifolia, Annona squamosa, A. reticulate, Azadirachta indica, Buchanania lanzan, Cassia fistula, Celastrus paniculatus, Centella asiatica, Clausena excavate, Cleome viscosa, Cleistanthus collinus, Clerodendrum indicum, Croton roxburghii, Diospyros melanoxylon, Eleutherine bulbosa, Erycibe paniculata, Eryngium foetidum, Garcinia cowa, Helicteres isora, Hemidesmus indicus, Holarrhena antidysenterica, Lannea coromandelica, Millettia extensa, Mimusops elengi, Nyctanthes arbor-tristis, Oroxylum indicum, Paederia foetida, Pterospermum acerifolium, Punica granatum, Semecarpus anacardium, Spondias pinnata, Terminalia alata and Vitex negundo were shown to have significant antimicrobial activity. The species

  7. Identification of traditional medicinal plant extracts with novel anti-influenza activity.

    Directory of Open Access Journals (Sweden)

    Dhivya Rajasekaran

    Full Text Available The emergence of drug resistant variants of the influenza virus has led to a need to identify novel and effective antiviral agents. As an alternative to synthetic drugs, the consolidation of empirical knowledge with ethnopharmacological evidence of medicinal plants offers a novel platform for the development of antiviral drugs. The aim of this study was to identify plant extracts with proven activity against the influenza virus. Extracts of fifty medicinal plants, originating from the tropical rainforests of Borneo used as herbal medicines by traditional healers to treat flu-like symptoms, were tested against the H1N1 and H3N1 subtypes of the virus. In the initial phase, in vitro micro-inhibition assays along with cytotoxicity screening were performed on MDCK cells. Most plant extracts were found to be minimally cytotoxic, indicating that the compounds linked to an ethnomedical framework were relatively innocuous, and eleven crude extracts exhibited viral inhibition against both the strains. All extracts inhibited the enzymatic activity of viral neuraminidase and four extracts were also shown to act through the hemagglutination inhibition (HI pathway. Moreover, the samples that acted through both HI and neuraminidase inhibition (NI evidenced more than 90% reduction in virus adsorption and penetration, thereby indicating potent action in the early stages of viral replication. Concurrent studies involving Receptor Destroying Enzyme treatments of HI extracts indicated the presence of sialic acid-like component(s that could be responsible for hemagglutination inhibition. The manifestation of both modes of viral inhibition in a single extract suggests that there may be a synergistic effect implicating more than one active component. Overall, our results provide substantive support for the use of Borneo traditional plants as promising sources of novel anti-influenza drug candidates. Furthermore, the pathways involving inhibition of hemagglutination

  8. Identification of initiating events using a master logic diagram in low-power and shutdown PSA for nuclear power plant

    International Nuclear Information System (INIS)

    Han, S. J.; Park, J. H.; Kim, T. W.; Ha, J. J.

    2003-01-01

    It is necessary to apply a formal technique instead of an empirical technique in the identification of initiating events for Low Power and ShutDown (LPSD) Probabilistic Safety Assessment (PSA) of Nuclear Power Plant (NPP). The present study focuses on the examination of Master Logic Diagram (MLD) technique as a formal technique in the identification of initiating events. The MLD technique is a deductive tool using top-down approach for the formal and logical indentification of initiating events. The present study modified the MLD used in the full power PSA considering the characteristics of LPSD operation. The modified MLD introduced a systematic formation in decomposition process of which the MLD for full power PSA lacked. The modified MLD was able to identify initiating events systematic and logical. However, the formal techniques including the MLD have a limitation for precisely identifying all of the initiating events. In order to overcome this limitation, it is necessary to combine it with an empirical technique. We expect that the modified MLD can be used in an upgrade of the current LPSD PSAs

  9. Experimental control of Spanish broom (Spartium junceum invading natural grasslands

    Directory of Open Access Journals (Sweden)

    Cristina Sanhueza

    2012-12-01

    Full Text Available A group of legumes generically known as brooms are among the most successful shrubs invading grasslands in South America and otherregions. These species share a set of biological features that enhance their invasiveness, such as abundant and long-lasting seed banks,aggressive root systems and rapid growth, combined with their ability for re-sprouting after cutting or burning and for avoiding herbivores.They grow in dense stands that exclude native vegetation and are able to change ecological processes, increasing fire frequency and intensity,and fixing atmospheric nitrogen. The Spanish broom (Spartium junceum is a shrub native form the Mediterranean that was introduced intothe Argentine Pampas grasslands where it spreads over remnants of pristine ecosystems, threatening their biodiversity. This paper reports theresults obtained after an adaptive management strategy aimed at controlling this species in a nature reserve, and compares the efficiency ofdifferent mechanical and chemical control techniques in terms of the number of plants killed and the effects on surrounding vegetation andon the recruitment of broom seedlings. Control was implemented in two phases, the first included three treatments: i cut at the base of theplant, ii cut followed by the immediate application of Togar (Picloram 3% + Triclopyr 6%, at a 5% dilution in diesel oil on top of the cut stump, and iii foliar spraying with Togar. The follow-up treatments, implemented one year later, consisted of spraying the re-sprouts with Togar (5% in diesel oil or Glyphosate 36% (2% in water. The best option in terms of controlling Spanish broom was spraying the resprouts with Togar which gave 100% mortality of the treated plants, compared with values of 40% - 100% re-sprouting for the other optionstested. None of the methods was associated with an increase in seedling recruitment, nor with significant changes in the vegetation in the immediate vicinity of the controlled brooms.

  10. Prescribed burning supports grassland biodiversity - A multi-species study

    Science.gov (United States)

    Valkó, Orsolya; Deák, Balázs; Magura, Tibor; Török, Péter; Kelemen, András; Tóth, Katalin; Horváth, Roland; Nagy, Dávid; Debnár, Zsuzsanna; Zsigrai, György; Kapocsi, István; Tóthmérész, Béla

    2017-04-01

    During ancient times, fire was an important factor shaping European landscapes. Nowadays, prescribed burning can be one of the most effective conservation tools for the management of open landscapes, controlling dominant species, reducing accumulated litter or decreasing wildfire risk. In a prescribed burning experiment, we studied the effects of fire on dry alkaline grasslands. We tested whether autumn prescribed burning can be an alternative conservation measure in these grasslands. We selected six sites in Hungary: in three sites, prescribed burning was applied in November 2011, while three sites remained unburnt. We studied the effects of fire on soil characteristics, plant biomass and on the vegetation and arthropod assemblages (isopods, spiders, ground beetles and rove beetles). Soluble salt content increased significantly in the burnt sites, but soil pH, organic matter, potassium and phosphorous did not change. We found that prescribed fire had several positive effects from the nature conservation viewpoint. Diversity and the number of flowering shoots were higher, and the cover of the dominant grass was lower in the burnt sites. Graminoid biomass was lower, while total, green and forb biomass were higher in the burnt plots compared to the control ones. Our findings suggest that prescribed burning fire did not harm arthropods; species-level analyses showed that out of the most abundant invertebrate species, the abundance of ten was not affected, one decreased and one increased after burning. Our findings highlight that mosaic prescribed fire is a viable management tool in open landscapes, because it supports plant diversity and does not threaten arthropods.

  11. Perennial filter strips reduce nitrate levels in soil and shallow groundwater after grassland-to-cropland conversion

    Science.gov (United States)

    Xiaobo Zhou; Matthew J. Helmers; Heidi Asbjornsen; Randy Kolka; Mark D. Tomer

    2010-01-01

    Many croplands planted to perennial grasses under the Conservation Reserve Program are being returned to crop production, and with potential consequences for water quality. The objective of this study was to quantify the impact of grassland-to-cropland conversion on nitrate-nitrogen (NO3-N) concentrations in soil and shallow groundwater and to...

  12. Studying long-term, large-scale grassland restoration outcomes to improve seeding methods and reveal knowledge gaps

    Science.gov (United States)

    1) Considerable research is currently focused on restoring the World’s degraded grasslands by introducing species from seed. The research is continually providing valuable new insights into early seeded plant establishment, but more emphasis on longer, larger studies is needed to better quantify s...

  13. Earthworm-induced N mineralization in fertilized grassland increases both N2O emission and crop-N uptake

    NARCIS (Netherlands)

    Lubbers, I.M.; Brussaard, L.; Otten, W.; Groenigen, van J.W.

    2011-01-01

    Earthworms can increase plant nitrogen (N) availability by stimulating mineralization of organic matter. However, recent studies show that they can also cause elevated emission of the greenhouse gas nitrous oxide (N2O). It is unclear to what extent these two effects occur in fertilized grasslands,

  14. Interactions between above- and belowground biota: importance for small-scale vegetation mosaics in a grassland ecosystem

    NARCIS (Netherlands)

    Blomqvist, M.M.; Olff, H.; Blaauw, M.B.; Bongers, T.; Van der Putten, W.H.

    2000-01-01

    Grasslands are often characterised by small-scale mosaics in plant community composition that contribute to their diversity. Although above- and belowground biota can both cause such mosaics, few studies have addressed their interacting effects. We studied multi-trophic interactions between

  15. Interactions between above- and belowground biota : importance for small-scale vegetation mosaics in a grassland ecosystem

    NARCIS (Netherlands)

    Blomqvist, N.M.; Olff, H.; Blaauw, M.B.; Bongers, T.; Putten, van der W.H.

    2000-01-01

    Grasslands are often characterised by small-scale mosaics in plant community composition that contribute to their diversity. Although above- and belowground biota can both cause such mosaics, few studies have addressed their interacting effects. We studied multi-trophic interactions between

  16. Past tree influence and prescribed fire mediate biotic interactions and community reassembly in a grassland-restoration experiment

    Science.gov (United States)

    Charles B. Halpern; Joseph A. Antos; Donald McKenzie; Annette M. Olson; Lara Souza

    2016-01-01

    1. Woody plant encroachment of grasslands is occurring globally, with profound ecological consequences. Attempts to restore herbaceous dominance may fail if the woody state is resilient or if intervention leads to an alternate, undesirable state. Restoration outcomes often hinge on biotic interactions – particularly on priority effects that inhibit or promote community...

  17. Dry grassland biodiversity conservation using low-intensity sheep and goat grazing management: case study in Prague (Czech republic)

    Czech Academy of Sciences Publication Activity Database

    Dostálek, J.; Frantík, Tomáš

    2008-01-01

    Roč. 17, č. 3 (2008), s. 1439-1454 ISSN 0960-3115 Institutional research plan: CEZ:AV0Z60050516 Keywords : dry grassland * grazing * plant diversity conservation Subject RIV: EF - Botanics Impact factor: 1.473, year: 2008

  18. Isolation and Identification of Active Compounds from Papaya Plants and Activities as Antimicrobial

    Science.gov (United States)

    Prasetya, A. T.; Mursiti, S.; Maryan, S.; Jati, N. K.

    2018-04-01

    Extraction and isolation of papaya seeds and leaves (Carica papaya L) has been performed using n-hexane and ethanol solvents. Further isolation of the extract obtained using ethyl acetate and diethyl ether solvents. The result of the phytochemical test of papaya extract obtained by mixture of an active compound of flavonoids, alkaloids, tannins, steroids, and saponins. Ethyl acetate isolates containing only flavonoids and diethyl ether isolates contain only alkaloids. Extracts and isolates from papaya plants had gram-positive antibacterial activity greater than the gram-negative bacteria, but both did not have antifungal activity. Papaya extracts have greater antibacterial activity than flavonoid isolates and alkaloid isolates. Strong antibacterial inhibitory sequences are extracts of papaya plants, flavonoid isolates, and alkaloid isolates.

  19. Identification of nonlinear dynamics in power plant components using neural networks

    International Nuclear Information System (INIS)

    Parlos, A.G.; Fernandez, B.; Tsai, W.K.

    1990-01-01

    Advances in digital computer technology have enabled widespread implementation of closed-loop digital control systems in a variety of industries. In some instances, however, the complexity of the plant and the uncertainty associated with the parameters involved in the mathematical modeling narrow the range of applicability of most systematic control system design methodologies. A multiyear project has been initiated to assess the feasibility of the artificial neural networks (ANNs) technology for computerized enhanced diagnostics and control of nuclear power plant components. At this stage of the project, a new methodology, based on backpropagation learning, has been developed for identifying the nonlinear dynamic systems from a set of input-output data known as the training set

  20. Seed Endophyte Microbiome of Crotalaria pumila Unpeeled: Identification of Plant-Beneficial Methylobacteria

    OpenAIRE

    Sánchez-López, Ariadna S.; Pintelon, Isabel; Stevens, Vincent; Imperato, Valeria; Timmermans, Jean-Pierre; González-Chávez, Carmen; Carrillo-González, Rogelio; Van Hamme, Jonathan; Vangronsveld, Jaco; Thijs, Sofie

    2018-01-01

    Metal contaminated soils are increasing worldwide. Metal-tolerant plants growing on metalliferous soils are fascinating genetic and microbial resources. Seeds can vertically transmit endophytic microorganisms that can assist next generations to cope with environmental stresses, through yet poorly understood mechanisms. The aims of this study were to identify the core seed endophyte microbiome of the pioneer metallophyte Crotalaria pumila throughout three generations, and to bet...

  1. Identification and Quantification of Several Mammalian Steroid Hormones in Plants by UPLC-MS/MS

    Czech Academy of Sciences Publication Activity Database

    Simerský, Radim; Novák, Ondřej; Morris, David; Pouzar, Vladimír; Strnad, Miroslav

    2009-01-01

    Roč. 28, č. 2 (2009), s. 125-136 ISSN 0721-7595 R&D Projects: GA AV ČR KAN200380801 Institutional research plan: CEZ:AV0Z50380511; CEZ:AV0Z40550506 Keywords : Ultra-performance liquid chromatography (UPLC) * Tandem mass spectrometry (MS/MS) * Immunoaffinity purification * Steroids * Plant extracts * Digitalis purpurea * Nicotiana tabacum * Inula helenium Subject RIV: EC - Immunology Impact factor: 2.438, year: 2009

  2. Identification of Insect-Plant Pollination Networks for a Midwest Installation: Fort McCoy, WI

    Science.gov (United States)

    2016-04-01

    species are dependent on animal pollinators, including many agricultural plants (Ollerton et al. 2011). The recent declines of polli- nator species...pollinator fauna be- cause these species were absent from the Fort McCoy Integrated Natural Resources Management Plan. For general application of these...Conservation Status Ranks were used to classify species according to their vulnerability to extinction . Only species with Global Ranks of G1 (critically

  3. The nutritive value of Valjevac grassland - Zasavica reservation

    Directory of Open Access Journals (Sweden)

    Grdović Svetlana

    2013-01-01

    Full Text Available Valjevac pasture of Zasavica reservation with its area of 300 ha presents a significant area for grazing cattle. In order to evaluate its potential for livestock production, the botanical and chemical composition of hay in three different time periods was observed (spring, summer and autumn. The determined plants species confirmed the richness of Zasavica grasslands, as well as the presence of dry, moist and forest habitat plants. The analyzed plants mostly belong to the Poaceae, Fabaceae, Asteraceae and Plantaginaceae families. Chemical analysis determined that the protein content decreased (P<0.01 from April (17.22±0.40 % to October (10.30±0.16 %, and cellulose content increased (P<0.01 (from 19.07±0.38 % in April to 21.65±0.41 % in October. The calculated energy density of hay samples ranged from 0.425 Starch Units (SU in October, 0.443 SU in April to 0.448 SU in June. The Valjevac pasture with its numerous plant species is of great importance in upkeeping biodiversity and also presents a solid base for livestock production. The determined levels of manganese and copper point out to the need of copper supplementation especially during the late summer and autumn periods. [Projekat Ministarstva nauke Republike Srbije, br. III46002

  4. FOOT ROT DISEASE IDENTIFICATION FOR VELLAIKODI VARIETY OF BETELVINE PLANTS USING DIGITAL IMAGE PROCESSING

    Directory of Open Access Journals (Sweden)

    J. Vijayakumar

    2012-11-01

    Full Text Available Betelvine plants are infected variety of diseases in the complete plantation without any premature warning of the diseases. The aim of this paper is to detection of foot rot disease in the vellaikodi variety of betelvine plants using digital image processing techniques. The digital images of the uninfected or normal betelvine leaves and the digital images of the infected in foot rot diseased betelvine leaves at different stages are collected from different Betelvine plants using a high resolution digital camera and collected betelvine images are stored with JPEG format. The digital images of the betelvine leaves analyses are done using the image processing toolbox in MATLAB which gives the normal patterns of the digital images. Using RGB encoding process, the RGB components of the betelvine leaves are separated. The mean and median values for all sample leaves are computed and calculated values are stored in the system. The mean and median values of test leaves are computed and compared with the stored values. As the result of this comparison, it is identified whether test leaves are affected by foot rot disease or not. Finally this analysis helps to recognize the foot rot disease can be identified before it spreads to entire crop.

  5. Development of a triple hyphenated HPLC-radical scavenging detection-DAD-SPE-NMR system for the rapid identification of antioxidants in complex plant extracts

    NARCIS (Netherlands)

    Pukalskas, A.; Beek, van T.A.; Waard, de P.

    2005-01-01

    A rapid method for the simultaneous detection and identification of radical scavenging compounds in plant extracts was developed by combining an HPLC with on-line radical scavenging using DPPH as a model radical and an HPLC¿DAD¿SPE¿NMR system. Using this method a commercial rosemary extract was

  6. High-resolution screening combined with HPLC–HRMS–SPE–NMR for identification of fungal plasma membrane H+-ATPase inhibitors from plants

    DEFF Research Database (Denmark)

    Kongstad, Kenneth; Wubshet, Sileshi Gizachew; Johannesen, Ane

    2014-01-01

    Crude extracts of 33 plant species were assessed for fungal plasma membrane (PM) H+-ATPase inhibition. This led to identification of 18 extracts showing more than 95% inhibition at a concentration of 7.5 mg/mL and/or a concentration-dependent activity profile. These extracts were selected for semi...

  7. Transcriptome characterization and sequencing-based identification of salt-responsive genes in Millettia pinnata, a semi-mangrove plant.

    Science.gov (United States)

    Huang, Jianzi; Lu, Xiang; Yan, Hao; Chen, Shouyi; Zhang, Wanke; Huang, Rongfeng; Zheng, Yizhi

    2012-04-01

    Semi-mangroves form a group of transitional species between glycophytes and halophytes, and hold unique potential for learning molecular mechanisms underlying plant salt tolerance. Millettia pinnata is a semi-mangrove plant that can survive a wide range of saline conditions in the absence of specialized morphological and physiological traits. By employing the Illumina sequencing platform, we generated ~192 million short reads from four cDNA libraries of M. pinnata and processed them into 108,598 unisequences with a high depth of coverage. The mean length and total length of these unisequences were 606 bp and 65.8 Mb, respectively. A total of 54,596 (50.3%) unisequences were assigned Nr annotations. Functional classification revealed the involvement of unisequences in various biological processes related to metabolism and environmental adaptation. We identified 23,815 candidate salt-responsive genes with significantly differential expression under seawater and freshwater treatments. Based on the reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR analyses, we verified the changes in expression levels for a number of candidate genes. The functional enrichment analyses for the candidate genes showed tissue-specific patterns of transcriptome remodelling upon salt stress in the roots and the leaves. The transcriptome of M. pinnata will provide valuable gene resources for future application in crop improvement. In addition, this study sets a good example for large-scale identification of salt-responsive genes in non-model organisms using the sequencing-based approach.

  8. Identification of Physiological Substrates and Binding Partners of the Plant Mitochondrial Protease FTSH4 by the Trapping Approach

    Directory of Open Access Journals (Sweden)

    Magdalena Opalińska

    2017-11-01

    Full Text Available Maintenance of functional mitochondria is vital for optimal cell performance and survival. This is accomplished by distinct mechanisms, of which preservation of mitochondrial protein homeostasis fulfills a pivotal role. In plants, inner membrane-embedded i-AAA protease, FTSH4, contributes to the mitochondrial proteome surveillance. Owing to the limited knowledge of FTSH4’s in vivo substrates, very little is known about the pathways and mechanisms directly controlled by this protease. Here, we applied substrate trapping coupled with mass spectrometry-based peptide identification in order to extend the list of FTSH4’s physiological substrates and interaction partners. Our analyses revealed, among several putative targets of FTSH4, novel (mitochondrial pyruvate carrier 4 (MPC4 and Pam18-2 and known (Tim17-2 substrates of this protease. Furthermore, we demonstrate that FTSH4 degrades oxidatively damaged proteins in mitochondria. Our report provides new insights into the function of FTSH4 in the maintenance of plant mitochondrial proteome.

  9. Reducing classification error of grassland overgrowth by combing low-density lidar acquisitions and optical remote sensing data

    Science.gov (United States)

    Pitkänen, T. P.; Käyhkö, N.

    2017-08-01

    Mapping structural changes in vegetation dynamics has, for a long time, been carried out using satellite images, orthophotos and, more recently, airborne lidar acquisitions. Lidar has established its position as providing accurate material for structure-based analyses but its limited availability, relatively short history, and lack of spectral information, however, are generally impeding the use of lidar data for change detection purposes. A potential solution in respect of detecting both contemporary vegetation structures and their previous trajectories is to combine lidar acquisitions with optical remote sensing data, which can substantially extend the coverage, span and spectral range needed for vegetation mapping. In this study, we tested the simultaneous use of a single low-density lidar data set, a series of Landsat satellite frames and two high-resolution orthophotos to detect vegetation succession related to grassland overgrowth, i.e. encroachment of woody plants into semi-natural grasslands. We built several alternative Random Forest models with different sets of variables and tested the applicability of respective data sources for change detection purposes, aiming at distinguishing unchanged grassland and woodland areas from overgrown grasslands. Our results show that while lidar alone provides a solid basis for indicating structural differences between grassland and woodland vegetation, and orthophoto-generated variables alone are better in detecting successional changes, their combination works considerably better than its respective parts. More specifically, a model combining all the used data sets reduces the total error from 17.0% to 11.0% and omission error of detecting overgrown grasslands from 56.9% to 31.2%, when compared to model constructed solely based on lidar data. This pinpoints the efficiency of the approach where lidar-generated structural metrics are combined with optical and multitemporal observations, providing a workable framework to

  10. Identification, duplication, evolution and expression analyses of caleosins in Brassica plants and Arabidopsis subspecies.

    Science.gov (United States)

    Shen, Yue; Liu, Mingzhe; Wang, Lili; Li, Zhuowei; Taylor, David C; Li, Zhixi; Zhang, Meng

    2016-04-01

    Caleosins are a class of Ca(2+) binding proteins that appear to be ubiquitous in plants. Some of the main proteins embedded in the lipid monolayer of lipid droplets, caleosins, play critical roles in the degradation of storage lipids during germination and in lipid trafficking. Some of them have been shown to have histidine-dependent peroxygenase activity, which is believed to participate in stress responses in Arabidopsis. In the model plant Arabidopsis thaliana, caleosins have been examined extensively. However, little is known on a genome-wide scale about these proteins in other members of the Brassicaceae. In this study, 51 caleosins in Brassica plants and Arabidopsis lyrata were investigated and analyzed in silico. Among them, 31 caleosins, including 7 in A. lyrata, 11 in Brassica oleracea and 13 in Brassica napus, are herein identified for the first time. Segmental duplication was the main form of gene expansion. Alignment, motif and phylogenetic analyses showed that Brassica caleosins belong to either the H-family or the L-family with different motif structures and physicochemical properties. Our findings strongly suggest that L-caleosins are evolved from H-caleosins. Predicted phosphorylation sites were differentially conserved in H-caleosin and L-caleosins, respectively. 'RY-repeat' elements and phytohormone-related cis-elements were identified in different caleosins, which suggest diverse physiological functions. Gene structure analysis indicated that most caleosins (38 out of 44) contained six exons and five introns and their intron phases were highly conserved. Structurally integrated caleosins, such as BrCLO3-3 and BrCLO4-2, showed high expression levels and may have important roles. Some caleosins, such as BrCLO2 and BoCLO8-2, lost motifs of the calcium binding domain, proline knot, potential phosphorylation sites and haem-binding sites. Combined with their low expression, it is suggested that these caleosins may have lost function.

  11. Identification of the real options in a program of nuclear plants

    International Nuclear Information System (INIS)

    Camacho G, D.; Diaz N, M. J.; Reinking C, A.

    2008-01-01

    The development of our societies and our economies this intimately related to electric power and this as well with the generating sources, due to the projection of world-wide growth should go associate with a strategy of growth of energy generation. Considering to the nuclear power as an option to satisfy the energy needs that a country can provide two main immediate benefits: The stabilization of prices of security of provision of electric power of the nation. The care of the environment, since the gas discharges greenhouse are almost null. At the moment nuclear energy represents economically a viable option for the capital investment, taking into account the development from technology, the policies implemented by the state and the prices of other fuels. Due to the great investment that its require for the nuclear plants are necessary to use financial tools that allow to analyze the future scenes in which ours investment can be seen affected and to value the flexibility of being able to enlarge, to postpone or to stop our project in order to have majors profits or to diminish the lost ones. This valuation of the flexibility can be obtained from the called method Real Options. By analysis of Real Options the process is understood to apply to the methodology of the Financial Options to the valuation of projects or the management of real assets. The Real Options appear in flexible plans, projects, activities or enterprise investments, like for example, to leave or to sell the investment project before concluding it, changing to their use or its technology, to prolong their life, the option to choose, one or the other capacity, among others possibilities. In this work is an example of the application of the method of Real Options in the decision to invest or to defer the investment for the construction of a nuclear plant following the behavior of the tariffs in the market or the costs of generation of other technologies with which a nuclear plant competes. (Author)

  12. Identification of Systemic Acquired Resistance–Related Volatile Organic Compounds and their Role in Plant Immunity

    OpenAIRE

    Bichlmeier, Marlies

    2017-01-01

    Systemic acquired resistance (SAR) is an inducible immune response that depends on ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1), which is essential for SAR signalling. In contrast to SAR, local resistance remains intact in Arabidopsis (Arabidopsis thaliana) eds1-2 mutant plants in response to Pseudomonas syringae delivering the effector protein AvrRpm1. I utilized the SAR-specific phenotype of the eds1-2 mutant to identify volatile organic compounds (VOCs) related to SAR. To this end, SAR was indu...

  13. Identification et étude phytochimique de plantes utilisées comme ...

    African Journals Online (AJOL)

    La présente étude réalisée sur les plantes diurétiques utilisées au sud Bénin et principalement à Porto-Novo a pour objectif d'identifier et de caractériser les groupes de substances chimiques contenus dans les drogues végétales utilisées comme diurétiques à Porto-Novo, pour le traitement traditionnel ou la prévention du ...

  14. Identification and Characterization of Novel Plant Adenylate Cyclases – The Arabidopsis Thaliana Potassium Uptake Permeases

    KAUST Repository

    Al-Younis, Inas M.

    2018-05-01

    Adenylyl Cyclases (ACs) catalyze the formation of the key universal second messenger adenosine 3’, 5’-cyclic monophosphate (cAMP) from adenosine 5’- triphosphate. Cyclic AMP participates in several signal transduction pathways and is present in bacteria and higher and lower eukaryotes including higher plants. Previous studies in plants have shown a role for cAMP in signal transduction during e.g. the cell cycle, elongation of the pollen tube and stimulation of protein kinase activity. More recently cAMP has been shown to play a role in stress responses. Interestingly, cAMP has also been shown to regulate ion transport in plant cells. Here we used a similar strategy that led to the discovery of the first guanylyl cyclase in plants that was based on the alignment of conserved and functionally assigned amino acids in the catalytic centre of annotated nucleotide cyclases from lower and higher eukaryotes, to identify a novel candidate ACs in Arabidopsis (Arabidopsis thaliana K+ Uptake 5 and 7). ATKUP5 and 7 are homologous to K+ uptake permeases (KUPs) from bacteria and high-affinity K+ transporters (HAKs) from fungi. The AC activity was investigated by recombinantly expressing the ATKUP5 and 7 AC domain in vitro and by complementation of an E. coli AC mutant (cyaA). Furthermore, ATKUP5 was tested for its ability to functionally complement a yeast mutant deficient in Trk1 and Trk2 high affinity potassium uptake transporters. Site-mutagenesis in the AC domain was used to test the effect of both functions in each other. Furthermore, ATKUP5 was characterized electrophysiologically in HEK-293 cells to characterize the nature of this transporter. The localization of the ATKUP5 in Arabidopsis was examined using a Green Fluorescent Protein (GFP) fusion with the ATKUP5 to determine whether ATKUP5 is expressed at the plasma or tonoplast membrane. Arabiodpsis thaliana of the wild type, overexpressing ATKUP5 and atkup5 mutant lines were used to examine phenotypic differences.

  15. Survey of artificial intelligence methods for detection and identification of component faults in nuclear power plants

    International Nuclear Information System (INIS)

    Reifman, J.

    1997-01-01

    A comprehensive survey of computer-based systems that apply artificial intelligence methods to detect and identify component faults in nuclear power plants is presented. Classification criteria are established that categorize artificial intelligence diagnostic systems according to the types of computing approaches used (e.g., computing tools, computer languages, and shell and simulation programs), the types of methodologies employed (e.g., types of knowledge, reasoning and inference mechanisms, and diagnostic approach), and the scope of the system. The major issues of process diagnostics and computer-based diagnostic systems are identified and cross-correlated with the various categories used for classification. Ninety-five publications are reviewed

  16. Density and success of bird nests relative to grazing on western Montana grasslands

    Science.gov (United States)

    Fondell, Thomas F.; Ball, I.J.

    2004-01-01

    Grassland birds are declining at a faster rate than any other group of North American bird species. Livestock grazing is the primary economic use of grasslands in the western United States, but the effects of this use on distribution and productivity of grassland birds are unclear. We examined nest density and success of ground-nesting birds on grazed and ungrazed grasslands in western Montana. In comparison to grazed plots, ungrazed plots had reduced forb cover, increased litter cover, increased litter depth, and increased visual obstruction readings (VOR) of vegetation. Nest density among 10 of 11 common bird species was most strongly correlated with VOR of plots, and greatest nest density for each species occurred where mean VOR of the plot was similar to mean VOR at nests. Additionally, all bird species were relatively consistent in their choice of VOR at nests despite substantial differences in VOR among plots. We suggest that birds selected plots based in part on availability of suitable nest sites and that variation in nest density relative to grazing reflected the effect of grazing on availability of nest sites. Nest success was similar between grazed plots and ungrazed plots for two species but was lower for nests on grazed plots than on ungrazed plots for two other species because of increased rates of predation, trampling, or parasitism by brown-headed cowbirds (Molothrus ater). Other species nested almost exclusively on ungrazed plots (six species) or grazed plots (one species), precluding evaluation of the effects of grazing on nest success. We demonstrate that each species in a diverse suite of ground-nesting birds preferentially used certain habitats for nesting and that grazing altered availability of preferred nesting habitats through changes in vegetation structure and plant species composition. We also show that grazing directly or indirectly predisposed some bird species to increased nesting mortality. Management alternatives that avoid

  17. Identification of lead chemotherapeutic agents from medicinal plants against blood flukes and whipworms.

    Science.gov (United States)

    Wangchuk, Phurpa; Giacomin, Paul R; Pearson, Mark S; Smout, Michael J; Loukas, Alex

    2016-08-30

    Schistosomiasis and trichuriasis are two of the most common neglected tropical diseases (NTD) that affect almost a billion people worldwide. There is only a limited number of effective drugs to combat these NTD. Medicinal plants are a viable source of parasiticides. In this study, we have investigated six of the 19 phytochemicals isolated from two Bhutanese medicinal plants, Corydalis crispa and Pleurospermum amabile, for their anthelmintic properties. We used the xWORM technique and Scanning Electron Microscope-based imaging to determine the activity of the compounds. Of the six compounds tested, isomyristicin and bergapten showed significant anthelmintic activity against Schistosoma mansoni and Trichuris muris with bergapten being the most efficacious compound one against both parasites (S. mansoni IC50 = 8.6 μg/mL and T. muris IC50 = 10.6 μg/mL) and also against the schistosomulum stage of S. mansoni. These two compounds induced tegumental damage to S. mansoni and affected the cuticle, bacillary bands and bacillary glands of T. muris. The efficacy against multiple phylogenetically distinct parasites and different life stages, especially the schistosomulum where praziquantel is ineffective, makes isomyristicin and bergapten novel scaffolds for broad-spectrum anthelmintic drug development that could be used for the control of helminths infecting humans and animals.

  18. Identification, expression, and taxonomic distribution of alternative oxidases in non-angiosperm plants.

    Science.gov (United States)

    Neimanis, Karina; Staples, James F; Hüner, Norman P A; McDonald, Allison E

    2013-09-10

    Alternative oxidase (AOX) is a terminal ubiquinol oxidase present in the respiratory chain of all angiosperms investigated to date, but AOX distribution in other members of the Viridiplantae is less clear. We assessed the taxonomic distribution of AOX using bioinformatics. Multiple sequence alignments compared AOX proteins and examined amino acid residues involved in AOX catalytic function and post-translational regulation. Novel AOX sequences were found in both Chlorophytes and Streptophytes and we conclude that AOX is widespread in the Viridiplantae. AOX multigene families are common in non-angiosperm plants and the appearance of AOX1 and AOX2 subtypes pre-dates the divergence of the Coniferophyta and Magnoliophyta. Residues involved in AOX catalytic function are highly conserved between Chlorophytes and Streptophytes, while AOX post-translational regulation likely differs in these two lineages. We demonstrate experimentally that an AOX gene is present in the moss Physcomitrella patens and that the gene is transcribed. Our findings suggest that AOX will likely exert an influence on plant respiration and carbon metabolism in non-angiosperms such as green algae, bryophytes, liverworts, lycopods, ferns, gnetophytes, and gymnosperms and that further research in these systems is required. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Identification and Evaluation of Human Factors Issues Associated with Emerging Nuclear Plant Technology

    International Nuclear Information System (INIS)

    O'Hara, J.M.; Higgins, J.; Brown, William S.

    2009-01-01

    This study has identified human performance research issues associated with the implementation of new technology in nuclear power plants (NPPs). To identify the research issues, current industry developments and trends were evaluated in the areas of reactor technology, instrumentation and control technology, human-system integration technology, and human factors engineering (HFE) methods and tools. The issues were prioritized into four categories based on evaluations provided by 14 independent subject matter experts representing vendors, utilities, research organizations and regulators. Twenty issues were categorized into the top priority category. The study also identifies the priority of each issue and the rationale for those in the top priority category. The top priority issues were then organized into research program areas of: New Concepts of Operation using Multi-agent Teams, Human-system Interface Design, Complexity Issues in Advanced Systems, Operating Experience of New and Modernized Plants, and HFE Methods and Tools. The results can serve as input to the development of a long-term strategy and plan for addressing human performance in these areas to support the safe operation of new NPPs.

  20. Superoxide Dismutase as a Tool for the Mulacular Identification of Plant Parasitic Nematodes

    Directory of Open Access Journals (Sweden)

    S. Molinari

    2004-08-01

    Full Text Available Superoxide dismutase (SOD is a constitutive family of enzymes produced by all aerobic organisms. Varying amounts of SOD activity have been found at all life stages of the most diffused plant parasitic nematodes. SOD is important to aerobic metabolism and parasitism of nematodes in that it catalyzes the first step of the neutralization of the highly toxic superoxide anion (O2 •-, which is largely produced in plant-nematode incompatible reactions. SOD has also been shown to be a significant tool to diagnose root-knot, cyst-, and longidorid nematodes. A high SOD polymorphism has been revealed by Native-Page on gradient polyacrylamide gels for Meloidogyne spp. and by isoelectrofocusing for Globodera, Xiphinema and Longidorus spp. The sensitivity of such procedures has been improved by using the PhastSystem (Amersham Biosciences, Piscata, NJ, USA, an automated equipment for electrophoresis. An accurate discrimination of species of all the nematode genera tested has been achieved and an attempt was made to group populations of the Xiphinema americanum-group and to detect Globodera rostochiensis and G. pallida pathotypes.

  1. Identification of cis-regulatory sequences that activate transcription in the suspensor of plant embryos.

    Science.gov (United States)

    Kawashima, Tomokazu; Wang, Xingjun; Henry, Kelli F; Bi, Yuping; Weterings, Koen; Goldberg, Robert B

    2009-03-03

    Little is known about the molecular mechanisms by which the embryo proper and suspensor of plant embryos activate specific gene sets shortly after fertilization. We analyzed the upstream region of the scarlet runner bean (Phaseolus coccineus) G564 gene to understand how genes are activated specifically within the suspensor during early embryo development. Previously, we showed that the G564 upstream region has a block of tandem repeats, which contain a conserved 10-bp motif (GAAAAG(C)/(T)GAA), and that deletion of these repeats results in a loss of suspensor transcription. Here, we use gain-of-function (GOF) experiments with transgenic globular-stage tobacco embryos to show that only 1 of the 5 tandem repeats is required to drive suspensor-specific transcription. Fine-scale deletion and scanning mutagenesis experiments with 1 tandem repeat uncovered a 54-bp region that contains all of the sequences required to activate transcription in the suspensor, including the 10-bp motif (GAAAAGCGAA) and a similar 10-bp-like motif (GAAAAACGAA). Site-directed mutagenesis and GOF experiments indicated that both the 10-bp and 10-bp-like motifs are necessary, but not sufficient to activate transcription in the suspensor, and that a sequence (TTGGT) between the 10-bp and the 10-bp-like motifs is also necessary for suspensor transcription. Together, these data identify sequences that are required to activate transcription in the suspensor of a plant embryo after fertilization.

  2. Resource-Mediated Indirect Effects of Grassland Management on Arthropod Diversity

    Science.gov (United States)

    Simons, Nadja K.; Gossner, Martin M.; Lewinsohn, Thomas M.; Boch, Steffen; Lange, Markus; Müller, Jörg; Pašalić, Esther; Socher, Stephanie A.; Türke, Manfred; Fischer, Markus; Weisser, Wolfgang W.

    2014-01-01

    Intensive land use is a driving force for biodiversity decline in many ecosystems. In semi-natural grasslands, land-use activities such as mowing, grazing and fertilization affect the diversity of plants and arthropods, but the combined effects of different drivers and the chain of effects are largely unknown. In this study we used structural equation modelling to analyse how the arthropod communities in managed grasslands respond to land use and whether these responses are mediated through changes in resource diversity or resource quantity (biomass). Plants were considered resources for herbivores which themselves were considered resources for predators. Plant and arthropod (herbivores and predators) communities were sampled on 141 meadows, pastures and mown pastures within three regions in Germany in 2008 and 2009. Increasing land-use intensity generally increased plant biomass and decreased plant diversity, mainly through increasing fertilization. Herbivore diversity decreased together with plant diversity but showed no response to changes in plant biomass. Hence, land-use effects on herbivore diversity were mediated through resource diversity rather than quantity. Land-use effects on predator diversity were mediated by both herbivore diversity (resource diversity) and herbivore quantity (herbivore biomass), but indirect effects through resource quantity were stronger. Our findings highlight the importance of assessing both direct and indirect effects of land-use intensity and mode on different trophic levels. In addition to the overall effects, there were subtle differences between the different regions, pointing to the importance of regional land-use specificities. Our study underlines the commonly observed strong effect of grassland land use on biodiversity. It also highlights that mechanistic approaches help us to understand how different land-use modes affect biodiversity. PMID:25188423

  3. The impact of nitrogen deposition on acid grasslands in the Atlantic region of Europe

    International Nuclear Information System (INIS)

    Stevens, Carly J.; Dupre, Cecilia; Dorland, Edu; Gaudnik, Cassandre; Gowing, David J.G.; Bleeker, Albert; Diekmann, Martin; Alard, Didier; Bobbink, Roland; Fowler, David; Corcket, Emmanuel; Mountford, J. Owen; Vandvik, Vigdis

    2011-01-01

    A survey of 153 acid grasslands from the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is changing plant species composition and soil and plant-tissue chemistry. Across the deposition gradient (2-44 kg N ha -1 yr -1 ) grass richness as a proportion of total species richness increased whereas forb richness decreased. Soil C:N ratio increased, but soil extractable nitrate and ammonium concentrations did not show any relationship with nitrogen deposition. The above-ground tissue nitrogen contents of three plant species were examined: Agrostis capillaris (grass), Galium saxatile (forb) and Rhytidiadelphus squarrosus (bryophyte). The tissue nitrogen content of neither vascular plant species showed any relationship with nitrogen deposition, but there was a weak positive relationship between R. squarrosus nitrogen content and nitrogen deposition. None of the species showed strong relationships between above-ground tissue N:P or C:N and nitrogen deposition, indicating that they are not good indicators of deposition rate. - Highlights: → N deposition is negatively correlated with forb richness as a proportion of species richness. → Soil C:N ratio increased with increasing N deposition. → Soil extractable nitrate and ammonium were not related to nitrogen deposition. → Plant-tissue N content was not a good indicator of N deposition. - Atmospheric nitrogen deposition affects soils, plant-tissue chemistry and plant species composition in acid grasslands in the Atlantic biogeographic region of Europe.

  4. The impact of nitrogen deposition on acid grasslands in the Atlantic region of Europe

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, Carly J., E-mail: c.j.stevens@open.ac.uk [Department of Life Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Dupre, Cecilia [Institute of Ecology, FB 2, University of Bremen, Leobener Str., DE-28359 Bremen (Germany); Dorland, Edu [Ecology and Biodiversity Group, Department of Biology, Institute of Environmental Biology, Utrecht University, PO Box 80.058, 3508 TB Utrecht (Netherlands); Gaudnik, Cassandre [University of Bordeaux 1, UMR INRA 1202 Biodiversity, Genes and Communities, Equipe Ecologie des Communautes, Batiment B8 - Avenue des Facultes, F-33405 Talence (France); Gowing, David J.G. [Department of Life Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Bleeker, Albert [Department of Air Quality and Climate Change, Energy Research Centre of the Netherlands, PO Box 1, 1755 ZG Petten (Netherlands); Diekmann, Martin [Institute of Ecology, FB 2, University of Bremen, Leobener Str., DE-28359 Bremen (Germany); Alard, Didier [University of Bordeaux 1, UMR INRA 1202 Biodiversity, Genes and Communities, Equipe Ecologie des Communautes, Batiment B8 - Avenue des Facultes, F-33405 Talence (France); Bobbink, Roland [B-WARE Research Centre, Radboud University, PO Box 9010, 6525 ED Nijmegen (Netherlands); Fowler, David [NERC Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian EH26 0QB (United Kingdom); Corcket, Emmanuel [University of Bordeaux 1, UMR INRA 1202 Biodiversity, Genes and Communities, Equipe Ecologie des Communautes, Batiment B8 - Avenue des Facultes, F-33405 Talence (France); Mountford, J. Owen [NERC Centre for Ecology and Hydrology, MacLean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB (United Kingdom); Vandvik, Vigdis [Department of Biology, University of Bergen, Box 7800, N-5020 Bergen (Norway)

    2011-10-15

    A survey of 153 acid grasslands from the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is changing plant species composition and soil and plant-tissue chemistry. Across the deposition gradient (2-44 kg N ha{sup -1} yr{sup -1}) grass richness as a proportion of total species richness increased whereas forb richness decreased. Soil C:N ratio increased, but soil extractable nitrate and ammonium concentrations did not show any relationship with nitrogen deposition. The above-ground tissue nitrogen contents of three plant species were examined: Agrostis capillaris (grass), Galium saxatile (forb) and Rhytidiadelphus squarrosus (bryophyte). The tissue nitrogen content of neither vascular plant species showed any relationship with nitrogen deposition, but there was a weak positive relationship between R. squarrosus nitrogen content and nitrogen deposition. None of the species showed strong relationships between above-ground tissue N:P or C:N and nitrogen deposition, indicating that they are not good indicators of deposition rate. - Highlights: > N deposition is negatively correlated with forb richness as a proportion of species richness. > Soil C:N ratio increased with increasing N deposition. > Soil extractable nitrate and ammonium were not related to nitrogen deposition. > Plant-tissue N content was not a good indicator of N deposition. - Atmospheric nitrogen deposition affects soils, plant-tissue chemistry and plant species composition in acid grasslands in the Atlantic biogeographic region of Europe.

  5. Carbohydrates and thermal properties indicate a decrease in stable aggregate carbon following forest colonization of mountain grassland

    DEFF Research Database (Denmark)

    Guidi, Claudia; Cannella, David; Leifeld, Jens

    2015-01-01

    and thermally labile C showed similar patterns in bulk soil, suggesting that thermal analysis can be used to complement chemical analysis although a straightforward relationship could not be established. Following forest expansion on abandoned grassland, ratios of microbially to plant-derived carbohydrates......In mountainous areas of Europe, the abandonment of grasslands followed by forest expansion is the dominant land-use change. Labile (i.e. easily decomposable) litter represents the major source for soil microbial products, which promote soil aggregation and long-term C stabilization. Our objective...... was to investigate changes in the content and origin of soil C components involved into aggregate stabilization (i.e. carbohydrates) following forest expansion on abandoned grassland in the Alps, where only few studies have been conducted. Changes in carbohydrates and thermally labile C were assessed along a land...

  6. Contrasting responses of grassland water and carbon exchanges to climate change between Tibetan Plateau and Inner Mongolia

    Science.gov (United States)

    Liu, D.; Li, Y.; Wang, T.; Peylin, P. P.; MacBean, N.; Ciais, P.; Jia, G.; Ma, M.; Ma, Y.; Shen, M.; Zhang, X.; Piao, S.

    2017-12-01

    he grassland in Tibetan Plateau (TP) and Inner Mongolia (IM) of China play important roles in climate change mitigation. These two regions have increasingly experienced warming and changing precipitation regimes over the past three decades. However, it remains uncertain to what extent temperature and water availability regulate the water and carbon fluxes across alpine (TP) and temperate (IM) grasslands. Here, we optimize a process-based model of carbon and water fluxes using eddy covariance (EC) data and analyze the simulated results based upon the optimized model exposed to a range of annual temperature and precipitation anomalies. We found that the changes of NEE of TP grassland are relatively small because of compatible increasing rate of ecosystem respiration (Re) and the gross primary productivity (GPP) under warming. The NEE of IM grassland increases with warming due to faster reduction of GPP than Re under warm-induced drought. We also found suppression of plant transpiration as the primary cause for the muted response of evapotranspiration to warming in IM, which is in contrast to enhanced transpiration in TP. We therefore highlight that the underlying processes regulating the responses of water and carbon cycles to warming are fundamentally different between TP and IM grasslands.

  7. Initial Soil Organic Matter Content Influences the Storage and Turnover of Litter-, Root- and Soil Carbon in Grasslands

    Science.gov (United States)

    Liu, L.; Xu, S.; Li, P.; Sayer, E. J.

    2017-12-01

    Grassland degradation is a worldwide problem that often leads to substantial loss of soil organic matter (SOM). Understanding how SOM content influences the stabilization of plant carbon (C) to form soil C is important to evaluate the potential of degraded grasslands to sequester additional C. We conducted a greenhouse experiment using C3 soils with six levels of SOM content and planted the C4 grass Cleistogenes squarrosa and/or added its litter to investigate how SOM content regulates the storage of new soil C derived from litter and roots, the decomposition of extant soil C, and the formation of soil aggregates. We found that microbial biomass carbon (MBC) increased with SOM content, and increased the mineralization of litter C. Both litter addition and planted treatments increased the amount of new C inputs to soil. However, litter addition had no significant impacts on the mineralization of extant soil C, but the presence of living roots significantly accelerated it. Thus, by the end of the experiment, soil C content was significantly higher in the litter addition treatments, but was not affected by planted treatments. The soil macroaggregate fraction increased with SOM content and was positively related to MBC. Overall, our study suggests that as SOM content increases, plant growth and soil microbes become more active, which allows microbes to process more plant-derived C and increases new soil C formation. The interactions between SOM content and plant C inputs should be considered when evaluating soil C turnover in degraded grasslands.

  8. Energy analysis of various grassland utilisation systems

    Directory of Open Access Journals (Sweden)

    Jozef Ržonca

    2005-01-01

    Full Text Available In 2003 and 2004 was carried out the energy analysis of the different types of permanent grassland utilization on the Hrubý Jeseník locality. There were estimated values of the particular entrances of additional energy. Energy entrances moved according to the pratotechnologies from 2.17 GJ. ha–1 to 22.70 GJ.ha–1. The biggest share on energy entrances had fertilizers. It was 84.93% by the nitrogen fertilisation. The most energy benefit of brutto and nettoenergy was marked by the low intensive utilisation (33.40 GJ.ha–1 NEL and 32.40 GJ.ha–1 NEV on average. The highest value of energy efficiency (13.23% was marked by the low intensive utilization of permanent grassland. By using of higher doses of industrial fertilizers has energy efficiency decreased. From view of energy benefit and intensiveness on energy entrances it appears the most available utilisation of permanent grassland with three cuts per year (first cut on May 31st at the latest, every next after 60 days or two cuts per year (first cut on July 15th, next cuts after 90 days.

  9. The Effects of Land-Use Change from Grassland to Miscanthus x giganteus on Soil N2O Emissions

    Directory of Open Access Journals (Sweden)

    Michael Williams

    2013-09-01

    Full Text Available A one year field trial was carried out on three adjacent unfertilised plots; an 18 year old grassland, a 14 year old established Miscanthus crop, and a 7 month old newly planted Miscanthus crop. Measurements of N2O, soil temperature, water filled pore space (WFPS, and inorganic nitrogen concentrations, were made every one to two weeks. Soil temperature, WFPS and NO3− and NH4+ concentrations were all found to be significantly affected by land use. Temporal crop effects were also observed in soil inorganic nitrogen dynamics, due in part to C4 litter incorporation into the soil under Miscanthus. Nonetheless, soil N2O fluxes were not significantly affected by land use. Cumulative yearly N2O fluxes were relatively low, 216 ± 163, 613 ± 294, and 377 ± 132 g·N·ha−1·yr−1 from the grassland, newly planted Miscanthus, and established Miscanthus plots respectively, and fell within the range commonly observed for unfertilised grasslands dominated by perennial ryegrass (Lolium perenne. Higher mean cumulative fluxes were measured in the newly planted Miscanthus, which may be linked to a possible unobserved increase immediately after establishment. However, these differences were not statistically significant. Based on the results of this experiment, land-use change from grassland to Miscanthus will have a neutral impact on medium to long-term N2O emissions.

  10. Seeding method influences warm-season grass abundance and distribution but not local diversity in grassland restoration

    Science.gov (United States)

    Yurkonis, Kathryn A.; Wilsey, Brian J.; Moloney, Kirk A.; Drobney, Pauline; Larson, Diane L.

    2010-01-01

    Ecological theory predicts that the arrangement of seedlings in newly restored communities may influence future species diversity and composition. We test the prediction that smaller distances between neighboring seeds in drill seeded grassland plantings would result in lower species diversity, greater weed abundance, and larger conspecific patch sizes than otherwise similar broadcast seeded plantings. A diverse grassland seed mix was either drill seeded, which places seeds in equally spaced rows, or broadcast seeded, which spreads see