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Sample records for old-field chronosequence plant

  1. Old-field plant succession on the Pajarito Plateau

    International Nuclear Information System (INIS)

    Foxx, T.; Mullen, M.; Salisbury, M.; Tierney, G.

    1997-10-01

    Eight fallow historic fields of the ponderosa pine and pinon-juniper cover types were surveyed to determine species composition and distribution. The purpose of the study was to understand plant succession on old fields as related to mechanically manipulated sites such as material disposal areas (MDAs). Additionally, the authors wanted a listing of species on disturbed lands of the Pajarito Plateau to aide in the reclamation planning of MDAs using native species. They also wanted to determine if any species could be used as an indicator of disturbance. The eight historic fields were all within Los Alamos County, New Mexico, and had been abandoned in 1943. Two sites were within the boundaries of Los Alamos National Laboratory and were studied both in 1982 and 1993. The study provides a description of each of the field sites, historic information about the homesteads from patent applications, a photographic record of some of the sites, and a listing of species found within each field. The study showed that there were 78 different plant species found on disturbed sites. Of these 78 species, 23 were found to be dominant on one or more of the MDAs or old fields. Although, the disturbance history of each site is imperfectly known, the study does provide an indication of successional processes within disturbed sites of the Pajarito Plateau. Additionally, it provides a listing of species that will invade disturbed sites, species that may be used in site reclamation

  2. Old-field plant succession on the Pajarito Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Foxx, T.; Mullen, M.; Salisbury, M. [Los Alamos National Lab., NM (United States); Tierney, G. [Tierney (Gail), Santa Fe, NM (United States)

    1997-10-01

    Eight fallow historic fields of the ponderosa pine and pinon-juniper cover types were surveyed to determine species composition and distribution. The purpose of the study was to understand plant succession on old fields as related to mechanically manipulated sites such as material disposal areas (MDAs). Additionally, the authors wanted a listing of species on disturbed lands of the Pajarito Plateau to aide in the reclamation planning of MDAs using native species. They also wanted to determine if any species could be used as an indicator of disturbance. The eight historic fields were all within Los Alamos County, New Mexico, and had been abandoned in 1943. Two sites were within the boundaries of Los Alamos National Laboratory and were studied both in 1982 and 1993. The study provides a description of each of the field sites, historic information about the homesteads from patent applications, a photographic record of some of the sites, and a listing of species found within each field. The study showed that there were 78 different plant species found on disturbed sites. Of these 78 species, 23 were found to be dominant on one or more of the MDAs or old fields. Although, the disturbance history of each site is imperfectly known, the study does provide an indication of successional processes within disturbed sites of the Pajarito Plateau. Additionally, it provides a listing of species that will invade disturbed sites, species that may be used in site reclamation.

  3. Seasonal and annual plant production of a southern Manitoba old-field

    International Nuclear Information System (INIS)

    Turner, B.N.; Iverson, S.L.

    1980-06-01

    The amount of natural variation in vegetation production during Project ZEUS (an investigation of long-term gamma radiation on meadow voles) will constitute an important habitat variable for the meadow vole population. To quantify this variation, annual and seasonal plant production of a nearby old-field was estimated by monthly harvests of aboveground vegetation between April and October for five consecutive years. The amount of dry green vegetation varied significantly both among years and months, peaking at a mean of nearly 300 G. M -2 in late July and late August. Mean rates of production were maximum in late May to late June, reaching 4.45 g.m -2 .d -1 . Dead vegetation varied significantly among months, but not among years, with peak amounts of nearly 800 G. M -2 in May and October. Moss quantities varied among years, but not among months, and showed a general trend to increase as the field aged. Monthly production of green vegetation showed some relationships to precipitation and temperature, and particularly indicated that hot dry springs impeded growth. Both amount and rate of green production were greater than that on most similar old-fields reported in the literature, and generally exceeded levels on all native grasslands except tallgrass prairie. Annual variability in peak green production was similar to that on other grasslands and old-fields. Variability in green production was greatest in April, and least in June, at the time when production was greatest. Greatest variation in green production occurred at the same time as greatest variation in temperature. Low precipitation may limit production, but the amount of precipitation does not appear to have an effect above a certain minimum level. (auth)

  4. Should Exotic Eucalyptus be Planted in Subtropical China: Insights from Understory Plant Diversity in Two Contrasting Eucalyptus Chronosequences.

    Science.gov (United States)

    Wu, Jianping; Fan, Houbao; Liu, Wenfei; Huang, Guomin; Tang, Jianfu; Zeng, Ruijin; Huang, Jing; Liu, Zhanfeng

    2015-11-01

    Although Eucalyptus is widely planted in South China, whose effects on native biodiversity are unclear. The objective of this study was to quantify the richness and composition of understory plants in two contrasting Eucalyptus chronosequences in South China. One was in Zhangzhou City with plantation age of 2, 4, and 6 years after clear-cutting Chinese fir forests, while the other was in Heshan City with plantation age of 2, 3, and 24 years that reforested on barren lands. Results showed that the richness of understory plants and functional groups was not significantly altered in the Zhangzhou chronosequence, while increased in the 24-year-old plantations, with a significantly larger proportion of woody plants than the younger plantations for the Heshan chronosequence. Moreover, a higher richness of woody plants accompanied by a lower richness of herbaceous species was detected in the Zhangzhou chronosequence compared with the Heshan one. To balance the need for pulp production and plant diversity conservation, we suggest that intercropping approaches between exotic Eucalyptus plantations and native forests should be considered in the fast rotation Eucalyptus plantations. However, Eucalyptus plantations may be used as pioneer species to sustain ecosystem functioning for the degraded lands.

  5. Plant phenodynamics of a southeastern Manitoba old-field during six years

    International Nuclear Information System (INIS)

    Turner, B.N.

    1980-09-01

    Natural variation in timing of vegetation phenological stages constitutes a habitat variable of potential importance to meadow vole populations. Changes in this timing resulting from the continuous gamma irradiation of the Project ZEUS irradiator may affect the vole population through reproductive, nutritional or other differences. To quantify the amount of natural variation present in phenological development, 36 species present on an old-field near the ZEUS meadows were assessed for stage of development each week during the snow-free season for six consecutive years. (auth)

  6. Links between plant and fungal communities across a deforestation chronosequence in the Amazon rainforest.

    Science.gov (United States)

    Mueller, Rebecca C; Paula, Fabiana S; Mirza, Babur S; Rodrigues, Jorge L M; Nüsslein, Klaus; Bohannan, Brendan J M

    2014-07-01

    Understanding the interactions among microbial communities, plant communities and soil properties following deforestation could provide insights into the long-term effects of land-use change on ecosystem functions, and may help identify approaches that promote the recovery of degraded sites. We combined high-throughput sequencing of fungal rDNA and molecular barcoding of plant roots to estimate fungal and plant community composition in soil sampled across a chronosequence of deforestation. We found significant effects of land-use change on fungal community composition, which was more closely correlated to plant community composition than to changes in soil properties or geographic distance, providing evidence for strong links between above- and below-ground communities in tropical forests.

  7. Effects of 'target' plant species body size on neighbourhood species richness and composition in old-field vegetation.

    Directory of Open Access Journals (Sweden)

    Brandon S Schamp

    Full Text Available Competition is generally regarded as an important force in organizing the structure of vegetation, and evidence from several experimental studies of species mixtures suggests that larger mature plant size elicits a competitive advantage. However, these findings are at odds with the fact that large and small plant species generally coexist, and relatively smaller species are more common in virtually all plant communities. Here, we use replicates of ten relatively large old-field plant species to explore the competitive impact of target individual size on their surrounding neighbourhoods compared to nearby neighbourhoods of the same size that are not centred by a large target individual. While target individuals of the largest of our test species, Centaurea jacea L., had a strong impact on neighbouring species, in general, target species size was a weak predictor of the number of other resident species growing within its immediate neighbourhood, as well as the number of resident species that were reproductive. Thus, the presence of a large competitor did not restrict the ability of neighbouring species to reproduce. Lastly, target species size did not have any impact on the species size structure of neighbouring species; i.e. they did not restrict smaller, supposedly poorer competitors, from growing and reproducing close by. Taken together, these results provide no support for a size-advantage in competition restricting local species richness or the ability of small species to coexist and successfully reproduce in the immediate neighbourhood of a large species.

  8. CO2, Temperature, and Soil Moisture Interactions Affect NDVI and Reproductive Phenology in Old-Field Plant Communities

    Science.gov (United States)

    Engel, C.; Weltzin, J.; Norby, R.

    2004-12-01

    Plant community composition and ecosystem function may be altered by global atmospheric and climate change, including increased atmospheric [CO2], temperature, and varying precipitation regimes. We are conducting an experiment at Oak Ridge National Laboratory (ORNL) utilizing open-top chambers to administer experimental treatments of elevated CO2 (+300 ppm), warming (+ 3 degrees Celsius), and varying soil moisture availability to experimental plant communities constructed of seven common old-field species, including C3 and C4 grasses, forbs, and legumes. During 2004 we monitored plant community phenology (NDVI) and plant reproductive phenology. Early in the year, NDVI was greater in wet treatment plots, and was unaffected by main effects of temperature or CO2. This result suggests that early in the season warming is insufficient to affect early canopy development. Differences in soil moisture sustained throughout the winter and into early spring may constitute an important control on early canopy greenup. Elevated CO2 alleviated detrimental effects of warming on NDVI, but only early in the season. As ambient temperatures increased, elevated temperatures negatively impacted NDVI only in the dry plots. Wetter conditions ameliorate the effects of warming on canopy greenness during the warmer seasons of the year. Warming increased rates of bolting, number of inflorescences, and time to reproductive maturity for Andropogon virginicus (a C4 bunchgrass). Solidago Canadensis (a C3 late-season forb) also produced flowers earlier in elevated temperatures. Conversely, none of the C3 grasses and forbs that bolt or flower in late spring or early summer responded to temperature or CO2. Results indicate that warming and drought may impact plant community phenology, and plant species reproductive phenology. Clearly community phenology is driven by complex interactions among temperature, water, and CO2 that change throughout the season. Our data stresses the importance of

  9. Ecosystem development after mangrove wetland creation: plant-soil change across a 20-year chronosequence

    Science.gov (United States)

    Osland, Michael J.; Spivak, Amanda C.; Nestlerode, Janet A.; Lessmann, Jeannine M.; Almario, Alejandro E.; Heitmuller, Paul T.; Russell, Marc J.; Krauss, Ken W.; Alvarez, Federico; Dantin, Darrin D.; Harvey, James E.; From, Andrew S.; Cormier, Nicole; Stagg, Camille L.

    2012-01-01

    Mangrove wetland restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove wetland losses. However, ecosystem development and functional equivalence in restored and created mangrove wetlands are poorly understood. We compared a 20-year chronosequence of created tidal wetland sites in Tampa Bay, Florida (USA) to natural reference mangrove wetlands. Across the chronosequence, our sites represent the succession from salt marsh to mangrove forest communities. Our results identify important soil and plant structural differences between the created and natural reference wetland sites; however, they also depict a positive developmental trajectory for the created wetland sites that reflects tightly coupled plant-soil development. Because upland soils and/or dredge spoils were used to create the new mangrove habitats, the soils at younger created sites and at lower depths (10-30 cm) had higher bulk densities, higher sand content, lower soil organic matter (SOM), lower total carbon (TC), and lower total nitrogen (TN) than did natural reference wetland soils. However, in the upper soil layer (0-10 cm), SOM, TC, and TN increased with created wetland site age simultaneously with mangrove forest growth. The rate of created wetland soil C accumulation was comparable to literature values for natural mangrove wetlands. Notably, the time to equivalence for the upper soil layer of created mangrove wetlands appears to be faster than for many other wetland ecosystem types. Collectively, our findings characterize the rate and trajectory of above- and below-ground changes associated with ecosystem development in created mangrove wetlands; this is valuable information for environmental managers planning to sustain existing mangrove wetlands or mitigate for mangrove wetland losses.

  10. The variable effects of soil nitrogen availability and insect herbivory on aboveground and belowground plant biomass in an old-field ecosystem

    DEFF Research Database (Denmark)

    Blue, Jarrod D.; Souza, Lara; Classen, Aimée T.

    2011-01-01

    in an old-field ecosystem. In 2004, we established 36 experimental plots in which we manipulated soil nitrogen (N) availability and insect abundance in a completely randomized plot design. In 2009, after 6 years of treatments, we measured aboveground biomass and assessed root production at peak growth...... not be limiting primary production in this ecosystem. Insects reduced the aboveground biomass of subdominant plant species and decreased coarse root production. We found no statistical interactions between N availability and insect herbivory for any response variable. Overall, the results of 6 years of nutrient...

  11. 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

  12. 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...

  13. Dynamics of vesicular-arbuscular mycorrhizae during old field succession.

    Science.gov (United States)

    Johnson, Nancy Collins; Zak, Donald R; Tilman, David; Pfleger, F L

    1991-05-01

    The species composition of vesicular-arbuscular mycorrhizal (VAM) fungal communities changed during secondary succession of abandoned fields based on a field to forest chronosequence. Twenty-five VAM fungal species were identified. Seven species were clearly early successional and five species were clearly late successional. The total number of VAM fungal species did not increase with successional time, but diversity as measured by the Shannon-Wiener index tended to increase, primarily because the community became more even as a single species, Glomus aggregatum, became less dominant in the older sites. Diversity of the VAM fungal community was positively correlated with soil C and N. The density of VAM fungi, as measured by infectivity and total spore count, first increased with time since abandonment and then decreased in the late successional forest sites. Within 12 abandoned fields, VAM fungal density increased with increasing soil pH, H 2 O soluble soil C, and root biomass, but was inversely related to extractable soil P and percent cover of non-host plant species. The lower abundance of VAM fungi in the forest sites compared with the field sites agrees with the findings of other workers and corresponds with a shift in the dominant vegetation from herbaceous VAM hosts to woody ectomycorrhizal hosts.

  14. Old-field Community, Climate and Atmospheric Manipulation

    Energy Technology Data Exchange (ETDEWEB)

    Aimee Classen

    2009-11-01

    We are in the process of finishing a number of laboratory, growth chamber and greenhouse projects, analyzing data, and writing papers. The projects reported addressed these subjects: How do climate and atmospheric changes alter aboveground plant biomass and community structure; Effects of multiple climate changes factors on plant community composition and diversity: what did we learn from a 5-year open-top chamber experiment using constructed old-field communities; Do atmospheric and climatic change factors interact to alter woody seedling emergence, establishment and productivity; Soil moisture surpasses elevated CO{sub 2} and temperature in importance as a control on soil carbon dynamics; How do climate and atmospheric changes alter belowground root and fungal biomass; How do climate and atmospheric changes alter soil microarthropod and microbial communities; How do climate and atmospheric changes alter belowground microbial function; Linking root litter diversity and microbial functioning at a micro scale under current and projected CO{sub 2} concentrations; Multifactor climate change effects on soil ecosystem functioning depend on concurrent changes in plant community composition; How do climate and atmospheric changes alter aboveground insect populations; How do climate and atmospheric changes alter festuca endophyte infection; How do climate and atmospheric changes soil carbon stabilization.

  15. The stage of soil development modulates rhizosphere effect along a High Arctic desert chronosequence.

    Science.gov (United States)

    Mapelli, Francesca; Marasco, Ramona; Fusi, Marco; Scaglia, Barbara; Tsiamis, George; Rolli, Eleonora; Fodelianakis, Stilianos; Bourtzis, Kostas; Ventura, Stefano; Tambone, Fulvia; Adani, Fabrizio; Borin, Sara; Daffonchio, Daniele

    2018-05-01

    In mature soils, plant species and soil type determine the selection of root microbiota. Which of these two factors drives rhizosphere selection in barren substrates of developing desert soils has, however, not yet been established. Chronosequences of glacier forelands provide ideal natural environments to identify primary rhizosphere selection factors along the changing edaphic conditions of a developing soil. Here, we analyze changes in bacterial diversity in bulk soils and rhizospheres of a pioneer plant across a High Arctic glacier chronosequence. We show that the developmental stage of soil strongly modulates rhizosphere community assembly, even though plant-induced selection buffers the effect of changing edaphic factors. Bulk and rhizosphere soils host distinct bacterial communities that differentially vary along the chronosequence. Cation exchange capacity, exchangeable potassium, and metabolite concentration in the soil account for the rhizosphere bacterial diversity. Although the soil fraction (bulk soil and rhizosphere) explains up to 17.2% of the variation in bacterial microbiota, the soil developmental stage explains up to 47.7% of this variation. In addition, the operational taxonomic unit (OTU) co-occurrence network of the rhizosphere, whose complexity increases along the chronosequence, is loosely structured in barren compared with mature soils, corroborating our hypothesis that soil development tunes the rhizosphere effect.

  16. The stage of soil development modulates rhizosphere effect along a High Arctic desert chronosequence

    KAUST Repository

    Mapelli, Francesca

    2018-01-09

    In mature soils, plant species and soil type determine the selection of root microbiota. Which of these two factors drives rhizosphere selection in barren substrates of developing desert soils has, however, not yet been established. Chronosequences of glacier forelands provide ideal natural environments to identify primary rhizosphere selection factors along the changing edaphic conditions of a developing soil. Here, we analyze changes in bacterial diversity in bulk soils and rhizospheres of a pioneer plant across a High Arctic glacier chronosequence. We show that the developmental stage of soil strongly modulates rhizosphere community assembly, even though plant-induced selection buffers the effect of changing edaphic factors. Bulk and rhizosphere soils host distinct bacterial communities that differentially vary along the chronosequence. Cation exchange capacity, exchangeable potassium, and metabolite concentration in the soil account for the rhizosphere bacterial diversity. Although the soil fraction (bulk soil and rhizosphere) explains up to 17.2% of the variation in bacterial microbiota, the soil developmental stage explains up to 47.7% of this variation. In addition, the operational taxonomic unit (OTU) co-occurrence network of the rhizosphere, whose complexity increases along the chronosequence, is loosely structured in barren compared with mature soils, corroborating our hypothesis that soil development tunes the rhizosphere effect.

  17. The stage of soil development modulates rhizosphere effect along a High Arctic desert chronosequence

    KAUST Repository

    Mapelli, Francesca; Marasco, Ramona; Fusi, Marco; Scaglia, Barbara; Tsiamis, George; Rolli, Eleonora; Fodelianakis, Stylianos; Bourtzis, Kostas; Ventura, Stefano; Tambone, Fulvia; Adani, Fabrizio; Borin, Sara; Daffonchio, Daniele

    2018-01-01

    In mature soils, plant species and soil type determine the selection of root microbiota. Which of these two factors drives rhizosphere selection in barren substrates of developing desert soils has, however, not yet been established. Chronosequences of glacier forelands provide ideal natural environments to identify primary rhizosphere selection factors along the changing edaphic conditions of a developing soil. Here, we analyze changes in bacterial diversity in bulk soils and rhizospheres of a pioneer plant across a High Arctic glacier chronosequence. We show that the developmental stage of soil strongly modulates rhizosphere community assembly, even though plant-induced selection buffers the effect of changing edaphic factors. Bulk and rhizosphere soils host distinct bacterial communities that differentially vary along the chronosequence. Cation exchange capacity, exchangeable potassium, and metabolite concentration in the soil account for the rhizosphere bacterial diversity. Although the soil fraction (bulk soil and rhizosphere) explains up to 17.2% of the variation in bacterial microbiota, the soil developmental stage explains up to 47.7% of this variation. In addition, the operational taxonomic unit (OTU) co-occurrence network of the rhizosphere, whose complexity increases along the chronosequence, is loosely structured in barren compared with mature soils, corroborating our hypothesis that soil development tunes the rhizosphere effect.

  18. Nitrogen Fertilization Increases Cottonwood Growth on Old-Field Soil

    Science.gov (United States)

    B. G. Blackmon; E. H. White

    1972-01-01

    Nitrogen (150 lb ./acre as NH4N03 ) applied to a 6-year-old eastern cottonwood plantation in an old field on Commerce silt loam soil increased diameter, basal area, and volume growth by 200 percent over untreated controls. The plantation did not respond to 100 pounds P per acre from concentrated superphosphate.

  19. Response of Tridens flavus (L.) A. S. Hitchc. to soil nutrients and disturbance in an early successional old field

    Science.gov (United States)

    Honu, Y.A.K.; Gibson, D.J.; Middleton, B.A.

    2006-01-01

    Soil nutrients and disturbance are two of the main abiotic factors that influence plant dominance (canopy cover), density, and fecundity in early successional old field plant communities. The manner in which the dominant species in old field successional systems respond to the interaction of nutrients and disturbance is poorly known. We examined the dominance, density of flowering tillers, and reproductive output of Tridens flavus, a perennial, warm-season bunchgrass that is important in old field succession, to varying soil nutrient and disturbance regimes. We tested the hypothesis that the interaction between nutrients and disturbance would influence the performance (cover, density, fecundity) of T. flavus. To test this hypothesis, we subjected 25 m2 experimental plots to various combinations of fertilizer and mowing treatments for eight years after initially plowing the field. The performance of T. flavus was measured by estimating percent cover for 8 years (1996-2003) and both density of flowering tillers and reproductive output (panicle length and number of branches per panicle) for three years (2001-2003). The pattern of canopy cover of T. flavus over the first eight years of succession varied over time depending on mowing regime. Dominance was significantly higher in plots that were fertilized only in years one and five than in annually fertilized and unfertilized control plots. The length of panicles and density of flowering tillers were both significantly greater in annually mowed plots than in unmowed plots. In the absence of mowing in particular, T. flavus became overtopped by woody species and declined in this old field community. Therefore, disturbances such as mowing and fertilization may be important in maintaining grasses such as Tridens flavus in old fields.

  20. Climate change alters seedling emergence and establishment in an old-field ecosystem.

    Directory of Open Access Journals (Sweden)

    Aimée T Classen

    2010-10-01

    Full Text Available Ecological succession drives large-scale changes in ecosystem composition over time, but the mechanisms whereby climatic change might alter succession remain unresolved. Here, we asked if the effects of atmospheric and climatic change would alter tree seedling emergence and establishment in an old-field ecosystem, recognizing that small shifts in rates of seedling emergence and establishment of different species may have long-term repercussions on the transition of fields to forests in the future.We introduced seeds from three early successional tree species into constructed old-field plant communities that had been subjected for 4 years to altered temperature, precipitation, and atmospheric CO(2 regimes in an experimental facility. Our experiment revealed that different combinations of atmospheric CO(2 concentration, air temperature, and soil moisture altered seedling emergence and establishment. Treatments directly and indirectly affected soil moisture, which was the best predictor of seedling establishment, though treatment effects differed among species.The observed impacts, coupled with variations in the timing of seed arrival, are demonstrated as predictors of seedling emergence and establishment in ecosystems under global change.

  1. The Influence of an Invasive Shrub, Buddleja Davidii on a Native Shrub, Griselinia Littoralis Transplanted into a New Zealand Floodplain Chronosequence

    Science.gov (United States)

    Griselinia littoralis, a native New Zealand shrub, was planted into a chronosequence (0 to 8 yrs since flooding) dominated by the non-indigenous shrub, Buddleja davidii in three New Zealand floodplains to determine to what extent facilitation and competitive inhibition may influe...

  2. Phosphorous bioavailability along a soil chronosequence

    Science.gov (United States)

    Roberts, K.; Vokhshoori, N. L.; Rosenthanl, A.; Turner, B. L.; Condron, L.; Paytan, A.

    2011-12-01

    In humid environments, as soils age nutrient loss through leaching and chemical trasformations affect the succession and composition of the biological communities. In particular phosphorus (P), often a limiting nutrient in terrestrial systems, tends to evolve into less bio-available forms over time, compounding loss through leaching. Thus P availability has the potential to strongly affect community productivity and structure. Low standing stock of P may not necessarily imply P limitation as the bio-available P pool is continuously recycled and re-utilized. Thus extensive recycling can reduce to varying extents the effect of P limitation. The bio-availability and recycling rates of P are difficult to measure; multiple sequential extraction processes have been developed to try to define and quantify the bio-availability of both inorganic and organic forms of P. In this preliminary study, we will present results of P concentrations in different soil fractions and oxygen isotopes in phosphate. These data together increase our understanding of P dynamics as soils age. The work is being done with a well characterized and dated chronosequence from the west coast of the South Island of New Zealand near the Haast River.

  3. A structural equation model to integrate changes in functional strategies during old-field succession.

    Science.gov (United States)

    Vile, Denis; Shipley, Bill; Garnier, Eric

    2006-02-01

    From a functional perspective, changes in abundance, and ultimately species replacement, during succession are a consequence of integrated suites of traits conferring different relative ecological advantages as the environment changes over time. Here we use structural equations to model the interspecific relationships between these integrated functional traits using 34 herbaceous species from a Mediterranean old-field succession and thus quantify the notion of a plant strategy. We measured plant traits related to plant vegetative and reproductive size, leaf functioning, reproductive phenology, seed mass, and production on 15 individuals per species monitored during one growing season. The resulting structural equation model successfully accounts for the pattern of trait covariation during the first 45 years post-abandonment using just two forcing variables: time since site abandonment and seed mass; no association between time since field abandonment and seed mass was observed over these herbaceous stages of secondary succession. All other predicted traits values are determined by these two variables and the cause-effect linkage between them. Adding pre-reproductive vegetative mass as a third forcing variable noticeably increased the predictive power of the model. Increasing the time after abandonment favors species with increasing life span and pre-reproductive biomass and decreasing specific leaf area. Allometric coefficients relating vegetative and reproductive components of plant size were in accordance with allometry theory. The model confirmed the trade-off between seed mass and seed number. Maximum plant height and seed mass were major determinants of reproductive phenology. Our results show that beyond verbal conceptualization, plant ecological strategies can be quantified and modeled.

  4. Stable isotopes of Hawaiian spiders reflect substrate properties along a chronosequence

    Science.gov (United States)

    Dawson, Todd E.; Gillespie, Rosemary G.

    2018-01-01

    The Hawaiian Islands offer a unique opportunity to test how changes in the properties of an isolated ecosystem are propagated through the organisms that occur within that ecosystem. The age-structured arrangement of volcanic-derived substrates follows a regular progression over space and, by inference, time. We test how well documented successional changes in soil chemistry and associated vegetation are reflected in organisms at higher trophic levels—specifically, predatory arthropods (spiders)—across a range of functional groups. We focus on three separate spider lineages: one that builds capture webs, one that hunts actively, and one that specializes on eating other spiders. We analyze spiders from three sites across the Hawaiian chronosequence with substrate ages ranging from 200 to 20,000 years. To measure the extent to which chemical signatures of terrestrial substrates are propagated through higher trophic levels, we use standard stable isotope analyses of nitrogen and carbon, with plant leaves included as a baseline. The target taxa show the expected shift in isotope ratios of δ15N with trophic level, from plants to cursorial spiders to web-builders to spider eaters. Remarkably, organisms at all trophic levels also precisely reflect the successional changes in the soil stoichiometry of the island chronosequence, demonstrating how the biogeochemistry of the entire food web is determined by ecosystem succession of the substrates on which the organisms have evolved. PMID:29576984

  5. Slow recovery of tropical old-field rainforest regrowth and the value and limitations of active restoration.

    Science.gov (United States)

    Shoo, Luke P; Freebody, Kylie; Kanowski, John; Catterall, Carla P

    2016-02-01

    There is current debate about the potential for secondary regrowth to rescue tropical forests from an otherwise inevitable cascade of biodiversity loss due to land clearing and scant evidence to test how well active restoration may accelerate recovery. We used site chronosequences to compare developmental trajectories of vegetation between self-organized (i.e., spontaneous) forest regrowth and biodiversity plantings (established for ecological restoration, with many locally native tree species at high density) in the Australian wet tropics uplands. Across 28 regrowth sites aged 1-59 years, some structural attributes reached reference rainforest levels within 40 years, whereas wood volume and most tested components of native plant species richness (classified by species' origins, family, and ecological functions) reached less than 50% of reference rainforest values. Development of native tree and shrub richness was particularly slow among species that were wind dispersed or animal dispersed with large (>10 mm) seeds. Many species with animal-dispersed seeds were from near-basal evolutionary lineages that contribute to recognized World Heritage values of the study region. Faster recovery was recorded in 25 biodiversity plantings of 1-25 years in which wood volume developed more rapidly; native woody plant species richness reached values similar to reference rainforest and was better represented across all dispersal modes; and species from near-basal plant families were better (although incompletely) represented. Plantings and regrowth showed slow recovery in species richness of vines and epiphytes and in overall resemblance to forest in species composition. Our results can inform decision making about when and where to invest in active restoration and provide strong evidence that protecting old-growth forest is crucially important for sustaining tropical biodiversity. © 2015 Society for Conservation Biology.

  6. Fine and Coarse-Scale Patterns of Vegetation Diversity on Reclaimed Surface Mine-land Over a 40-Year Chronosequence.

    Science.gov (United States)

    Bohrer, Stefanie L; Limb, Ryan F; Daigh, Aaron L; Volk, Jay M; Wick, Abbey F

    2017-03-01

    Rangelands are described as heterogeneous, due to patterning in species assemblages and productivity that arise from species dispersal and interactions with environmental gradients and disturbances across multiple scales. The objectives of rangeland reclamation are typically vegetation establishment, plant community productivity, and soil stability. However, while fine-scale diversity is often promoted through species-rich seed mixes, landscape heterogeneity and coarse-scale diversity are largely overlooked. Our objectives were to evaluate fine and coarse-scale vegetation patterns across a 40-year reclamation chronosequence on reclaimed surface coalmine lands. We hypothesized that both α-diversity and β-diversity would increase and community patch size and species dissimilarity to reference sites would decrease on independent sites over 40 years. Plant communities were surveyed on 19 post-coalmine reclaimed sites and four intact native reference sites in central North Dakota mixed-grass prairie. Our results showed no differences in α or β-diversity and plant community patch size over the 40-year chronosequence. However, both α-diversity and β-diversity on reclaimed sites was similar to reference sites. Native species establishment was limited due to the presence of non-native species such as Kentucky bluegrass (Poa pratensis) on both the reclaimed and reference sites. Species composition was different between reclaimed and reference sites and community dissimilarity increased on reclaimed sites over the 40-year chronosequence. Plant communities resulting from reclamation followed non-equilibrium succession, even with consistent seeds mixes established across all reclaimed years. This suggests post-reclamation management strategies influence species composition outcomes and land management strategies applied uniformly may not increase landscape-level diversity.

  7. Size distributions and dispersions along a 485-year chronosequence for sand dune vegetation.

    Science.gov (United States)

    Waugh, Jennifer M; Aarssen, Lonnie W

    2012-04-01

    Using a sand dune chronosequence that spans 485 years of primary succession, we collected nearest-neighbor vegetation data to test two predictions associated with the traditional "size-advantage" hypothesis for plant competitive ability: (1) the relative representation of larger species should increase in later stages of succession; and (2) resident species that are near neighbors should, over successional time, become more similar in plant body size and/or seed size than expected by random assembly. The first prediction was supported over the time period between mid to later succession, but the second prediction was not; that is, there was no temporal pattern across the chronosequence indicating that either larger resident species, or larger seeded resident species, increasingly exclude smaller ones from local neighborhoods over time. Rather, neighboring species were generally more different from each other in seed sizes than expected by random assembly. As larger species accumulate over time, some relatively small species are lost from later stages of succession, but species size distributions nevertheless remain strongly right-skewed-even in late succession-and species of disparate sizes are just as likely as in early succession to coexist as immediate neighbors. This local-scale coexistence of disparate sized neighbors might be accounted for-as in traditional interpretations-in terms of species differences in "physical-space-niches" (e.g., involving different rooting depths), combined with possible facilitation effects. We propose, however, that this coexistence may also occur because competitive ability involves more than just a size advantage, with traits associated with survival (tolerance of intense competition) and fecundity (offspring production despite intense competition) being at least equally important.

  8. Biogenic and pedogenic controls on Si distributions and cycling in grasslands of the Santa Cruz soil chronosequence, California

    Science.gov (United States)

    White, Art F.; Vivit, Davison V.; Schulz, Marjorie S.; Bullen, Tom D.; Evett, Rand R.; Aagarwal, Jugdeep

    2012-10-01

    Biogenic and pedogenic processes control silica cycling in grasslands growing on a soil chronosequence and dominated by strong seasonal variabilities of a Mediterranean climate. Shallow pore water Si, in spite of significant annual uptake and release by plant growth and dieback, exhibits only moderate seasonal fluctuations reflecting strong buffering from labile biogenic Si, dominated by phytoliths and by secondary pedogenic silicates. Long phytolith residence times (340-900 yrs) reflect the seasonally dry climate and high solute Si concentrations. Water-extractable Si is closely associated with Al, indicating seasonal precipitation and dissolution of a highly labile 1:1 hydroxyaluminosilicate (HAS), probably allophane, which transforms in deeper soil into fine grained, poorly crystalline kaolinite. Shallow plant roots extract greater proportions of biogenic Si and deeper plant roots larger amounts pedogenic Si. High pore water Ge/Si in late winter and spring reflects the reinforcing effects of plant fractionation and concurrent dissolution of Ge-enriched HAS. The same processes produce pore waters with depleted 30Si/28Si. In the summer and fall, Ge/Si declines and 30Si/28Si increases, reflecting the cessation of plant uptake, continued dissolution of soil phytoliths and re-precipitation of less soluble HAS. Si inputs from weathering (2-90 mmol m-2 yr-1) and losses from pore water discharge (18-68 mM m-2 yr-1) are comparable for individual soils, decline with soil age and are significantly less than amounts of Si annual cycled through the vegetation (42-171 mM m-2 yr-1). Mobile Si is generally balanced in the soils with upward bio-pumping by the shallow-rooted grasses efficiently competing against downward leaching and pore water discharge. Small net annual increases in Si in the present day soils could not have been maintained over the time scale represented by the chronosequence (65-225 yrs), implying past changes in environmental conditions.

  9. A Chronosequence Feasibility Assessment of Emergency Fire Rehabilitation Records within the Intermountain Western United States - Final Report to the Joint Fire Science Program - Project 08-S-08

    Science.gov (United States)

    Knutson, Kevin C.; Pyke, David A.; Wirth, Troy A.; Pilliod, David S.; Brooks, Matthew L.; Chambers, Jeanne C.

    2009-01-01

    determine whether sufficient documentation existed for a future field-based chronosequence project. We collected ESR records and data at nine BLM field offices in four States (Oregon, Idaho, Nevada, and Utah) and examined the utility of these data for the development of a chronosequence study of post-fire seeding treatments from multiple sites and different ages (since seeding) throughout the Intermountain West. We collected records from 730 post-fire seeding projects with 1,238 individual seeding treatments. Records from each project ranged from minimal reporting of the project's occurrence to detailed documentation of planning, implementation, and monitoring. Of these 1,238 projects, we identified 468 (38 percent) that could potentially be used to implement a field-based chronosequence study. There were 206 ground-seeding treatments and 262 aerial-seeding treatments within this initial population, not including hand plantings. We also located a considerable number of additional records from other potential field offices that would be available for the chronosequence study but have yet to be compiled for this feasibility report. There are a number of potential challenges involved in going forward with a field-based chronosequence study derived from data collected at these nine BLM offices. One challenge is that not all seed mixtures in ESR project files have on-the-ground confirmation about what was sown or rates of application. Most projects, particularly records before 2000, just list the planned or purchased seed mixtures. Although this could potentially bias assessments of factors influencing establishment rates of individual species for treatments conducted before 2000, a chronosequence study would not be intended to assess success solely at the species-level. Treatment success would be evaluated based on the establishment of healthy vegetation communities, such as the abundance and density of perennial species, regardless of their lifeforms (grasses, fo

  10. LBA-ECO ND-30 Nutrient Analysis and Gas Fluxes, Forest Chronosequences, Para, Brazil:

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides fine litterfall mass and nutrient concentrations from samples collected at chronosequences established at Sao Francisco do Para and Capitao...

  11. LBA-ECO ND-30 Nutrient Analysis and Gas Fluxes, Forest Chronosequences, Para, Brazil:

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides fine litterfall mass and nutrient concentrations from samples collected at chronosequences established at Sao Francisco do Para and...

  12. LBA-ECO ND-30 Nutrient Analysis and Gas Fluxes, Forest Chronosequences, Para, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides fine litterfall mass and nutrient concentrations from samples collected at chronosequences established at Sao Francisco do Para and Capitao...

  13. LBA-ECO ND-10 Soil Properties of Pasture Chronosequences, Para, Brazil: 1997

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides the results of soil physical property and chemical measurements of samples collected from two pasture chronosequences (years since...

  14. LBA-ECO ND-10 Soil Properties of Pasture Chronosequences, Para, Brazil: 1997

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides the results of soil physical property and chemical measurements of samples collected from two pasture chronosequences (years since conversion...

  15. Soil bacterial and fungal communities along a soil chronosequence assessed by fatty acid profiling

    Czech Academy of Sciences Publication Activity Database

    Welc, M.; Bünemann, E. K.; Flieβbach, A.; Frossard, E.; Jansa, Jan

    2012-01-01

    Roč. 49, JUN 2012 (2012), s. 184-192 ISSN 0038-0717 Institutional support: RVO:61388971 Keywords : Fatty acid methyl esters * Glacier forefield * Soil chronosequence Subject RIV: EE - Microbiology, Virology Impact factor: 3.654, year: 2012

  16. Lichen specific thallus mass and secondary compounds change across a retrogressive fire-driven chronosequence.

    Science.gov (United States)

    Asplund, Johan; Sandling, Aron; Wardle, David A

    2012-01-01

    In the long-term absence of major disturbances ecosystems enter a state of retrogression, which involves declining soil fertility and consequently a reduction in decomposition rates. Recent studies have looked at how plant traits such as specific leaf mass and amounts of secondary compounds respond to declining soil fertility during retrogression, but there are no comparable studies for lichen traits despite increasing recognition of the role that lichens can play in ecosystem processes. We studied a group of 30 forested islands in northern Sweden differing greatly in fire history, and collectively representing a retrogressive chronosequence, spanning 5000 years. We used this system to explore how specific thallus mass (STM) and carbon based secondary compounds (CBSCs) change in three common epiphytic lichen species (Hypogymnia phsyodes, Melanohalea olivacea and Parmelia sulcata) as soil fertility declines during this retrogression. We found that STMs of lichens increased sharply during retrogression, and for all species soil N to P ratio (which increased during retrogression) was a strong predictor of STM. When expressed per unit area, medullary CBSCs in all species and cortical CBSCs in P. sulcata increased during retrogression. Meanwhile, when expressed per unit mass, only cortical CBSCs in H. physodes responded to retrogression, and in the opposite direction. Given that lichen functional traits are likely to be important in driving ecological processes that drive nutrient and carbon cycling in the way that plant functional traits are, the changes that they undergo during retrogression could potentially be significant for the functioning of the ecosystem.

  17. Species frequency dynamics in an old-field succession: Effects of disturbance, fertilization and scale

    Science.gov (United States)

    Gibson, D.J.; Middleton, B.A.; Foster, K.; Honu, Y.A.K.; Hoyer, E.W.; Mathis, M.

    2005-01-01

    Question: Can patterns of species frequency in an old-field be explained within the context of a metapopulation model? Are the patterns observed related to time, spatial scale, disturbance, and nutrient availability? Location: Upland and lowland old-fields in Illinois, USA. Method: Species richness was recorded annually for seven years following plowing of an upland and lowland old-field subject to crossed fertilizer and disturbance treatments (mowing and rototilling). Species occupancy distributions were assessed with respect to the numbers of core and satellite species. Results: In both fields, species richness became higher in disturbed plots than in undisturbed plots over time, and decreased in fertilized plots irrespective of time. A bimodal pattern of species richness consistent with the Core-satellite species (CSS) hypothesis occurred in the initial seed bank and through the course of early succession. The identity of native and exotic core species (those present in > 90% of blocks) changed with time. Some core species from the seed bank became core species in the vegetation, albeit after several years. At the scale of individual plots, a bimodal fit consistent with the CSS hypothesis applied only in year 1 and rarely thereafter. Conclusions: The CSS hypothesis provides a metapopulation perspective for understanding patterns of species richness but requires the assessment of spatial and temporal scaling effects. Regional processes (e.g. propagule availability) at the largest scale have the greatest impact influencing community structure during early secondary succession. Local processes (e.g., disturbance and soil nutrients) are more important at smaller scales and place constraints on species establishment and community structure of both native and exotic species. Under the highest intensity of disturbance, exotic species may be able to use resources unavailable to, or unused by, native species. ?? IAVS; Opulus Press.

  18. Field and laboratory procedures used in a soil chronosequence study

    Science.gov (United States)

    Singer, Michael J.; Janitzky, Peter

    1986-01-01

    In 1978, the late Denis Marchand initiated a research project entitled "Soil Correlation and Dating at the U.S. Geological Survey" to determine the usefulness of soils in solving geologic problems. Marchand proposed to establish soil chronosequences that could be dated independently of soil development by using radiometric and other numeric dating methods. In addition, by comparing dated chronosequences in different environments, rates of soil development could be studied and compared among varying climates and mineralogical conditions. The project was fundamental in documenting the value of soils in studies of mapping, correlating, and dating late Cenozoic deposits and in studying soil genesis. All published reports by members of the project are included in the bibliography.The project demanded that methods be adapted or developed to ensure comparability over a wide variation in soil types. Emphasis was placed on obtaining professional expertise and on establishing consistent techniques, especially for the field, laboratory, and data-compilation methods. Since 1978, twelve chronosequences have been sampled and analyzed by members of this project, and methods have been established and used consistently for analysis of the samples.The goals of this report are to:Document the methods used for the study on soil chronosequences,Present the results of tests that were run for precision, accuracy, and effectiveness, andDiscuss our modifications to standard procedures.Many of the methods presented herein are standard and have been reported elsewhere. However, we assume less prior analytical knowledge in our descriptions; thus, the manual should be easy to follow for the inexperienced analyst. Each chapter presents one or more references of the basic principle, an equipment and reagents list, and the detailed procedure. In some chapters this is followed by additional remarks or example calculations.The flow diagram in figure 1 outlines the step-by-step procedures used to

  19. Soil nutrient content of old-field and agricultural ecosystems exposed to chronic gamma irradiation

    International Nuclear Information System (INIS)

    Armentano, T.V.; Holt, B.R.; Bottino, P.J.

    1975-01-01

    Soil nutrients (extractable P. and NO 3 -N, exchangeable Ca, Mg and K), exchangeable Al, pH and organic matter content were measured over the top six inches of the soils of the seven-year old-field portion and the cultivated portion of the Brookhaven gamma field. Although concentrations of all nutrient elements were higher in the agricultural soil, the distributions of Ca, P, Al, pH and organic matter were similar along the radiation gradient in both fields. There was also a regular reduction in the phosphorus with decreasing exposure, but distribution of other elements was not clearly related to radiation effects. The distribution of all elements except K was significantly correlated with pH in the agricultural soil. In the old-field only Ca, Mg and Al showed this relationship. The most conspicuous effects of nearly 25 yr of chronic irradiation of the site were a reduction in soil organic matter content and an increase in soil P in both fields. (author)

  20. Landuse legacies of old-field succession and soil structure at the Calhoun Criticl Zone Observatory in SC, USA.

    Science.gov (United States)

    Brecheisen, Z. S.; Richter, D. D., Jr.; Callaham, M.; Carrera-Martinez, R.; Heine, P.

    2017-12-01

    The pre-colonial Southern Piedmont was an incredibly stable CZ with erosion rates between 0.35-3m/Myr on a 4th order interfluve. With soils and saprolite weathered up to 30m in total depth bedrock with multi-million year residence times under continual forest cover prior to widespread agricultural disturbance. With this biogeomorphic stability came time for soil macroporosity and soil structure to be established and maintained by the activities of soil fauna, plant root growth and death, and tree-fall tip-up events serving to continually mix and aerate the soil. Greatly accelerated surficial agricultural erosion (ca. 1750-1930) has fundamentally altered the Calhoun Critical Zone Observatory forest community dynamics aboveground and the soil structure, hydrology, and biogeochemistry belowground. The arrival of the plow to the Southern Piedmont marked the destruction of soil structure, macropore networks, and many of the macroinvertebrate soil engineers. This transformation came via forest clearing, soil tilling, compaction, and wholesale soil erosion, with the region having lost an estimated average of 18cm of soil across the landscape. In the temporal LULC progression from hardwood forests, to cultivated farms, to reforestation, secondary forest soil structure is expected to remain altered compared to the reference hardwood ecosystems. The research presented herein seeks to quantify CZ soil structure regeneration in old-field pine soil profiles' Ksat, aggregation, texture, macro-invertebrates, and direct measurements of topsoil porosity using X-ray computed tomography analysis on 15cm soil cores.

  1. Salt Marsh Ecosystem Responses to Restored Tidal Connectivity across a 14y Chronosequence

    Science.gov (United States)

    Capooci, M.; Spivak, A. C.; Gosselin, K.

    2016-02-01

    Salt marshes support valuable ecosystem services. Yet, human activities negatively impact salt marsh function and contribute to their loss at a global scale. On Cape Cod, MA, culverts and impoundments under roads and railways restricted tidal exchange and resulted in salt marsh conversion to freshwater wetlands. Over the past 14 y, these structures have been removed or replaced, restoring tidal connectivity between marshes and a saltwater bay. We evaluated differences in plant community composition, sediment properties, and pore water chemistry in marshes where tidal connectivity was restored using a space-for-time, or chronosequence approach. Each restored marsh was paired with a nearby, natural salt marsh to control for variability between marshes. In each restored and natural salt marsh we evaluated the plant community by measuring species-specific percent cover and biomass and collected sediment cores for bulk density and pore water analyses. Plant communities responded rapidly: salt-tolerant species, such as Spartina alterniflora, became established while freshwater species, including Phragmites australis, were less abundant within 3 y of restoration. The number of plant species was generally greater in marshes restored within 10 y, compared to older and natural marshes. Sediment bulk density varied with depth and across sites. This likely reflects differences in site history and local conditions. Deeper horizons (24-30cm) generally had higher values in restored sites while surface values (0-3cm) were similar in restored and natural marshes. Porewater pH and sulfide were similar in restored and natural marshes, suggesting rapid microbial responses to seawater reintroduction. Overall, marsh properties and processes reflecting biological communities responded rapidly to tidal restoration. However, variability between study locations underscores the potential importance of site history, local hydrology, and geomorphology in shaping marsh biogeochemistry.

  2. ORCHIDEE-CNP: Site-Scale Evaluation against Observations from a Soil Formation Chronosequence in Hawaii

    Science.gov (United States)

    Goll, D. S.; Vuichard, N.; Maignan, F.; Jornet-Puig, A.; Sardans, J.; Peng, S.; Sun, Y.; Kvakić, M.; Guimberteau, M.; Guenet, B.; Zaehle, S.; Penuelas, J.; Jannssens, I.; Ciais, P.

    2017-12-01

    Land surface models rarely incorporate the terrestrial phosphorus cycle and its interactions with the carbon cycle, despite the extensive scientific debate about the importance of nitrogen and phosphorus supply for future land carbon uptake. We describe a representation of the terrestrial phosphorus cycle for the land surface model ORCHIDEE, and evaluate it with data from nutrient manipulation experiments along a soil formation chronosequence in Hawaii. ORCHIDEE accounts for influence of nutritional state of vegetation on tissue nutrient concentrations, photosynthesis, plant growth, biomass allocation, biochemical (phosphatase-mediated) mineralization and biological nitrogen fixation. Changes in nutrient content (quality) of litter affect the carbon use efficiency of decomposition and in return the nutrient availability to vegetation. The model explicitly accounts for root zone depletion of phosphorus as a function of root phosphorus uptake and phosphorus transport from soil to the root surface. The model captures the observed differences in the foliage stoichiometry of vegetation between an early (300yr) and a late stage (4.1 Myr) of soil development. The contrasting sensitivities of net primary productivity to the addition of either nitrogen, phosphorus or both among sites are in general reproduced by the model. As observed, the model simulates a preferential stimulation of leaf level productivity when nitrogen stress is alleviated, while leaf level productivity and leaf area index are stimulated equally when phosphorus stress is alleviated. The nutrient use efficiencies in the model are lower as observed primarily due to biases in the nutrient content and turnover of woody biomass.

  3. Mechanisms for dominance in an early successional old field by the invasive non-native Lespedeza cuneata (Dum. Cours.) G. Don

    Science.gov (United States)

    Brandon, A.L.; Gibson, D.J.; Middleton, B.A.

    2004-01-01

    Researchers studying invasive plants often concentrate their efforts on predictive models thought to allow invasive plants to dominate native landscapes. However, if an invasive is already well established then experimental research is necessary to provide the information necessary to effectively manage the species. Prescribing appropriate management strategies without prior experimental research may not only be ineffective but also may squander limited resources or have the unintended consequence of furthering spread. Lespedeza cuneata (Dum. Cours.) G. Don. is a well-established invasive plant of old fields and tall-grass prairie in the US. Managers suspect this species shades-out native plants and this is proposed as its primary mechanism for dominance. Using field experiments we tested probable factors allowing the speices to establish itself and once established, interfere in old field plant communities. We also examined the effects of two common anthropogenic disturbances (mowing and nutrients) on L. cuneata growth and establishment. When L. cuneata was treated (clipping, herbicide and stem pull-back) there was a significant increase in species richness and native speices cover. Stem density and canopy cover of L. cuneata increased significantly with mowing frequency but decreased with nutrient input. We suggest that mowing benefits L. cuneata while also hindering woody competition. Results also indicate L. cuneata is less prevalent on nutrient enriched soils than on unamended soil. Lespedeza cuneata appears to suppress native plants by shading them out and it can subsequently take over grassland communities. Since it has a varying response to human induced disturbances and may actually benefit from mowing, land managers should be cautious when utilizing this as a management tool.

  4. Biological transfer and loss of 36Cl-labeled DDT in an old-field ecosystem

    International Nuclear Information System (INIS)

    Peterle, T.J.

    1979-01-01

    An enclosed 10-acre old-field plot treated in June 1969, with chlorine-36 labeled DDT was sampled each year from 1969 through 1974 to monitor the fate of the insecticide in the soil and biota. In order to provide data on compartmentalization of DDT in the vegetation, invertebrates and vertebrates inhabiting the plot, sampling was carried out to estimate both body burdens of DDT and biomass of populations. Another aspect of this study, the determination of rates of accumulation of residues by invertebrates and vertebrates, has been reported previously (Forsyth and Peterle 1973; Forsyth et al. 1975; Peterle 1975). This report describes (a) temporal patterns of DDT residues in soil and biota from 1969 through 1974 and (b) quantities of DDT held in the soil and biotic compartments of the ecosystem. Part II of the report is concerned with translocation and accumulation of 14 C-DDT

  5. Shifts in microbial communities and soil nutrients along a fire chronosequence in Alaskan boreal forest

    Science.gov (United States)

    Treseder, K. K.; Mack, M. C.; Cross, A.

    2002-12-01

    Fires are important pathways of carbon loss from boreal forests, while microbial communities form equally important mechanisms for carbon accumulation between fires. We used a chronosequence in Alaska to examine shifts in microbial abundance and community composition in the several decades following severe fire, and then related these responses to soil characteristics in the same sites. The sites are located in upland forests near Delta Junction, Alaska, and represent stages at 3-, 15-, 45-, and over 100-yr following fire. Plant communities shift from herbaceous species in the youngest site, to deciduous shrubs and trees (e.g. Populus tremuloides and Salix) in the intermediate sites, to black spruce (Picea mariana) forest in the oldest site. Soil organic matter accumulated 2.8-fold over time. Potential mineralization was highest in the intermediate-aged sites, as was nitrification and standing pools of inorganic nitrogen. In contrast, inorganic phosphorus pools were highest immediately following fire, and then decreased nine-fold with age. As measured with BiologTM plates, bacterial diversity and abundance were greatest in the oldest sites. Plant roots in the intermediate-aged sites displayed higher colonization by ecto- and arbuscular mycorrhizal fungi than those in the youngest and oldest sites. Likewise, glomalin, a glycoprotein produced by arbuscular mycorrhizal fungi, was most abundant in the 14-yr old site. Glomalin is believed to contribute to the formation of water-stable aggregates in the soil. However, water stable aggregates were most abundant in the younger sites and did not follow the pattern of glomalin or arbuscular mycorrhizal abundance. Our results indicate that fire may maintain landscape-level diversity of microbial functional groups, and that carbon sequestration in microbial tissues (e.g. glomalin and fungal biomass) may be greatest in areas that have burned several decades earlier. Changes in soil structure may not be directly attributable to

  6. Pedogenic silica accumulation in chronosequence soils, southern California

    Science.gov (United States)

    Kendrick, K.J.; Graham, R.C.

    2004-01-01

    Chronosequential analysis of soil properties has proven to be a valuable approach for estimating ages of geomorphic surfaces where no independent age control exists. In this study we examined pedogenic silica as an indicator of relative ages of soils and geomorphic surfaces, and assessed potential sources of the silica. Pedogenic opaline silica was quantified by tiron (4,5-dihydroxy-1,3-benzene-disulfonic acid [disodium salt], C6H 4Na2O8S2) extraction for pedons in two different chromosequences in southern California, one in the San Timoteo Badlands and one in Cajon Pass. The soils of hoth of these chronosequences are developed in arkosic sediments and span 11.5 to 500 ka. The amount of pedogenic silica increases with increasing duration of pedogenesis, and the depth of the maximum silica accumulation generally coincides with the maximum expression of the argillic horizon. Pedogenic silica has accumulated in all of the soils, ranging from 1.2% tiron-extractable Si (Sitn) in the youngest soil to 4.6% in the oldest. Primary Si decreases with increasing duration of weathering, particularly in the upper horizons, where weathering conditions are most intense. The loss of Si coincides with the loss of Na and K, implicating the weathering of feld-spars as the likely source of Si loss. The quantity of Si lost in the upper horizons is adequate to account for the pedogenic silica accumulation in the subsoil. Pedogenic silica was equally effective as pedogenic Fe oxides as an indicator of relative soil age in these soils.

  7. Soil organic matter formation and sequestration across a forested floodplain chronosequence

    Science.gov (United States)

    John D. Wigginton; B. Graeme Lockaby; Carl C. Trettin

    2000-01-01

    Successional changes in soil organic matter formation and carbon sequestration across a forested floodplain chronosequence were studied at the Savannah river site, National Environmental Research Park, SC, US. Four floodplain sites were selected for study, three of which are in various stages of recovery from impact due to thermal effluent discharge. The fourth is a...

  8. Carbon stocks across a chronosequence of thinned and unmanaged red pine (Pinus resinosa) stands

    Science.gov (United States)

    Matthew D. Powers; Randall K. Kolka; John B. Bradford; Brian J. Palik; Shawn Fraver; Martin F. Jurgensen

    2012-01-01

    Forests function as a major global C sink, and forest management strategies that maximize C stocks offer one possible means of mitigating the impacts of increasing anthropogenic CO2 emissions. We studied the effects of thinning, a common management technique in many forest types, on age-related trends in C stocks using a chronosequence of thinned...

  9. Changes in down dead wood volume across a chronosequence of silvicultural openings in southern Indiana forests

    Science.gov (United States)

    Michael A. Jenkins; George R. Parker

    1997-01-01

    The volume and decay stages of down dead wood were evaluated across a chronosequence of 46 silvicultural openings and 10 uncut control stands to determine how down dead wood volume changes with stand development. Openings ranged in age from 8 to 26 years and were divided into three age groups: (1) 16 years. Individual logs...

  10. Nitrogen balance along a northern boreal forest fire chronosequence.

    Science.gov (United States)

    Palviainen, Marjo; Pumpanen, Jukka; Berninger, Frank; Ritala, Kaisa; Duan, Baoli; Heinonsalo, Jussi; Sun, Hui; Köster, Egle; Köster, Kajar

    2017-01-01

    Fire is a major natural disturbance factor in boreal forests, and the frequency of forest fires is predicted to increase due to climate change. Nitrogen (N) is a key determinant of carbon sequestration in boreal forests because the shortage of N limits tree growth. We studied changes in N pools and fluxes, and the overall N balance across a 155-year non stand-replacing fire chronosequence in sub-arctic Pinus sylvestris forests in Finland. Two years after the fire, total ecosystem N pool was 622 kg ha-1 of which 16% was in the vegetation, 8% in the dead biomass and 76% in the soil. 155 years after the fire, total N pool was 960 kg ha-1, with 27% in the vegetation, 3% in the dead biomass and 69% in the soil. This implies an annual accumulation rate of 2.28 kg ha-1 which was distributed equally between soil and biomass. The observed changes in N pools were consistent with the computed N balance +2.11 kg ha-1 yr-1 over the 155-year post-fire period. Nitrogen deposition was an important component of the N balance. The biological N fixation increased with succession and constituted 9% of the total N input during the 155 post-fire years. N2O fluxes were negligible (≤ 0.01 kg ha-1 yr-1) and did not differ among post-fire age classes. The number and intensity of microbial genes involved in N cycling were lower at the site 60 years after fire compared to the youngest and the oldest sites indicating potential differences in soil N cycling processes. The results suggest that in sub-arctic pine forests, the non-stand-replacing, intermediate-severity fires decrease considerably N pools in biomass but changes in soil and total ecosystem N pools are slight. Current fire-return interval does not seem to pose a great threat to ecosystem productivity and N status in these sub-arctic forests.

  11. Water balance in afforestation chronosequences of common oak and Norway spruce on former arable land in Denmark and southern Sweden

    NARCIS (Netherlands)

    Rosenqvist, L.; Hansen, K.; Vesterdal, L.; Salm, van der C.

    2010-01-01

    Precipitation, throughfall and soil moisture were measured, and interception, transpiration and water recharge were estimated in four afforestation chronosequences on former arable land at two Danish locations (Vestskoven and Gejlvang) and at one southern Swedish location (Tonnersjoheden).

  12. Synchrotron-based P K-edge XANES spectroscopy reveals rapid changes of phosphorus speciation in the topsoil of two glacier foreland chronosequences

    Science.gov (United States)

    Prietzel, Jörg; Dümig, Alexander; Wu, Yanhong; Zhou, Jun; Klysubun, Wantana

    2013-05-01

    Phosphorus (P) is a crucial element for life on Earth, and the bioavailability of P in terrestrial ecosystems, which is dependent on the soil P stock and its speciation, may limit ecosystem productivity and succession. In our study, for the first time a direct speciation of soil P in two glacier foreland chronosequences has been conducted using synchrotron-based X-ray Absorption Near-Edge Structure (XANES) spectroscopy. The chronosequences are located in the forefields of Hailuogou Glacier (Gongga Shan, China) and Damma Glacier (Swiss Alps). The age since deglaciation of the investigated soils ranges from 0 to 120 years at Hailuogou, and from 15 to >700 years at Damma. Differences in climate conditions (cooler at Damma, in contrast to Hailuogou precluding the establishment of forest in advanced ecosystem succession stages) and in the chemical composition of the parent material result in different soil contents of total P and Fe/Al oxyhydroxides, which are much smaller at Damma than at Hailuogou. Nevertheless, both chronosequences show similar trends of their topsoil P status with increasing soil age. Our study reveals a rapid change of topsoil P speciation in glacier retreat areas already during initial stages of pedogenesis: Initially dominating bedrock-derived apatite-P and Al-bound P is depleted; Fe-bound P and particularly organically-bound P is accumulated. Organic P strongly dominates in the topsoil of the mature soils outside the proglacial area of Damma Glacier (age 700-3000 years), and already 50 years after deglacation in the topsoil of the retreat area of Hailuogou Glacier. A key factor for the change in topsoil P speciation is the establishment of vegetation, resulting in soil organic matter (SOM) accumulation as well as accelerated soil acidification and apatite dissolution by organic acids, which are produced by SOM-degrading micro-organisms, mykorrhiza fungi, and plant roots. Particularly the succession of grassland to forest seems to accelerate the

  13. Carbon and Water Exchanges in a Chronosequence of Temperate White Pine Forest

    Science.gov (United States)

    Arain, M.; Restrepo, N.; Pejam, M.; Khomik, M.

    2003-12-01

    Quantification of carbon sink or source strengths of temperate forest ecosystems, growing in northern mid-latitudes, is essential to resolve uncertainties in carbon balance of the world's terrestrial ecosystems. Long-term flux measurements are needed to quantify seasonal and annual variability of carbon and water exchanges from these ecosystems and to relate the variability to environmental and physiological factors. Such long-term measurements are of particular interest for different stand developmental stages. An understanding of environmental control factors is necessary to improve predictive capabilities of terrestrial carbon and water cycles. A long-term year-round measurement program has been initiated to observe energy, water vapour, and carbon dioxide fluxes in a chronosequence of white pine (Pinus Strobus) forests in southeastern Canada. White pine is an important species in the North American landscape because of its ability to adapt to dry environments. White pine efficiently grows on coarse and sandy soils, where other deciduous and conifer species cannot survive. Generally, it is the first woody species to flourish after disturbances such as fire and clearing. The climate at the study site is temperate, with a mean annual temperature of 8 degree C and a mean annual precipitation of about 800 mm. The growing season is one of the longest in Canada, with at least 150 frost-free days. Measurements at the site began in June 2002 and are continuing at present. Flux measurements at the 60 year old stand are being made using a close-path eddy covariance (EC) system, while fluxes at the three younger stands (30, 15 and 1 year old) are being measured over 10 to 20 day periods using a roving open-path EC system Soil respiration is being measured every 2-weeks across 50-m transects at all four sites using a mobile chamber system (LI-COR 6400). The mature stand was a sink of carbon with annual NEP value of 140 g C m-2 from June 2002 to May 2003. Gross ecosystem

  14. Active old-field restoration in the most arid lands of the Great Basin

    Science.gov (United States)

    Restoration of former agricultural fields can be challenging, especially in arid systems, where factors such as wind erosion, water stress, soil alteration, and competition from weeds can strongly affect plant establishment and growth. Experiments were conducted in two former agricultural fields in ...

  15. Patterns of biomass and carbon distribution across a chronosequence of Chinese pine (Pinus tabulaeformis) forests.

    Science.gov (United States)

    Zhao, Jinlong; Kang, Fengfeng; Wang, Luoxin; Yu, Xiaowen; Zhao, Weihong; Song, Xiaoshuai; Zhang, Yanlei; Chen, Feng; Sun, Yu; He, Tengfei; Han, Hairong

    2014-01-01

    Patterns of biomass and carbon (C) storage distribution across Chinese pine (Pinus tabulaeformis) natural secondary forests are poorly documented. The objectives of this study were to examine the biomass and C pools of the major ecosystem components in a replicated age sequence of P. tabulaeformis secondary forest stands in Northern China. Within each stand, biomass of above- and belowground tree, understory (shrub and herb), and forest floor were determined from plot-level investigation and destructive sampling. Allometric equations using the diameter at breast height (DBH) were developed to quantify plant biomass. C stocks in the tree and understory biomass, forest floor, and mineral soil (0-100 cm) were estimated by analyzing the C concentration of each component. The results showed that the tree biomass of P. tabulaeformis stands was ranged from 123.8 Mg·ha-1 for the young stand to 344.8 Mg·ha-1 for the mature stand. The understory biomass ranged from 1.8 Mg·ha-1 in the middle-aged stand to 3.5 Mg·ha-1 in the young stand. Forest floor biomass increased steady with stand age, ranging from 14.9 to 23.0 Mg·ha-1. The highest mean C concentration across the chronosequence was found in tree branch while the lowest mean C concentration was found in forest floor. The observed C stock of the aboveground tree, shrub, forest floor, and mineral soil increased with increasing stand age, whereas the herb C stock showed a decreasing trend with a sigmoid pattern. The C stock of forest ecosystem in young, middle-aged, immature, and mature stands were 178.1, 236.3, 297.7, and 359.8 Mg C ha-1, respectively, greater than those under similar aged P. tabulaeformis forests in China. These results are likely to be integrated into further forest management plans and generalized in other contexts to evaluate C stocks at the regional scale.

  16. Patterns of biomass and carbon distribution across a chronosequence of Chinese pine (Pinus tabulaeformis forests.

    Directory of Open Access Journals (Sweden)

    Jinlong Zhao

    Full Text Available Patterns of biomass and carbon (C storage distribution across Chinese pine (Pinus tabulaeformis natural secondary forests are poorly documented. The objectives of this study were to examine the biomass and C pools of the major ecosystem components in a replicated age sequence of P. tabulaeformis secondary forest stands in Northern China. Within each stand, biomass of above- and belowground tree, understory (shrub and herb, and forest floor were determined from plot-level investigation and destructive sampling. Allometric equations using the diameter at breast height (DBH were developed to quantify plant biomass. C stocks in the tree and understory biomass, forest floor, and mineral soil (0-100 cm were estimated by analyzing the C concentration of each component. The results showed that the tree biomass of P. tabulaeformis stands was ranged from 123.8 Mg·ha-1 for the young stand to 344.8 Mg·ha-1 for the mature stand. The understory biomass ranged from 1.8 Mg·ha-1 in the middle-aged stand to 3.5 Mg·ha-1 in the young stand. Forest floor biomass increased steady with stand age, ranging from 14.9 to 23.0 Mg·ha-1. The highest mean C concentration across the chronosequence was found in tree branch while the lowest mean C concentration was found in forest floor. The observed C stock of the aboveground tree, shrub, forest floor, and mineral soil increased with increasing stand age, whereas the herb C stock showed a decreasing trend with a sigmoid pattern. The C stock of forest ecosystem in young, middle-aged, immature, and mature stands were 178.1, 236.3, 297.7, and 359.8 Mg C ha-1, respectively, greater than those under similar aged P. tabulaeformis forests in China. These results are likely to be integrated into further forest management plans and generalized in other contexts to evaluate C stocks at the regional scale.

  17. Variations in canopy and litter interception across a forest chronosequence in the southern Appalachian Mountains

    Science.gov (United States)

    Steven T. Brantley; Paul V. Bolstad; Stephanie H. Laseter; A. Christopher Oishi; Kimberly A. Novick; Chelcy F. Miniat

    2016-01-01

    Variations in evapotranspiration (ET) have been well documented across a variety of forest types and climates in recent decades; however, most of these data have focused on mature, secondgrowth stands. Here we present data on two important fluxes of water, canopy interception (Ic) and forest floor litter interception (Iff), across a chronosequence of forest age in the...

  18. Abandonment terraced hillside and answer of the fire system: some results from Mediterranean old fields

    Energy Technology Data Exchange (ETDEWEB)

    Llovet Lopez, J.; Ruiz Varela, M.; Josa March, R.; Vallejo Calzada, V. R.

    2009-07-01

    The abandonment of agricultural lands promotes temporal changes both in soil characteristics (i.e., increasing organic matter and other quality indicators) and in plant community (i.e., changing its composition and structure, and increasing the fuel load). As a consequence, we can expect differences in the resilience to fire as succession progresses. The aim of this work is to analyse the capacity of an ecosystem to return to pre-fire conditions as a function of the stage of abandonment of old agricultural lands. The study was carried out in the north of Alicante province (E Spain). In long-term abandoned lands, post-fire modulated plant response, which in turn determined soil crusting, runoff and erosion dynamics. In recently-abandoned lands, the plant community seemed less dependent on ratio to recover. Results show a large increase in soil surface crusting in the short term after the fire and it remained high at medium term in long-abandoned lands colonised by pine forest. Fire scarcely modified runoff and erosion in recently-abandoned lands whereas in forest lands the post-fire values increased by some orders of magnitude and remained highly dependent on rain characteristics in the short and medium term after the fire. The results obtained show evidence of increased vulnerability to fire in long-abandoned lands colonised by pine forests. (Author) 4 refs.

  19. Abandonment terraced hillside and answer of the fire system: some results from Mediterranean old fields

    International Nuclear Information System (INIS)

    Llovet Lopez, J.; Ruiz Varela, M.; Josa March, R.; Vallejo Calzada, V. R.

    2009-01-01

    The abandonment of agricultural lands promotes temporal changes both in soil characteristics (i.e., increasing organic matter and other quality indicators) and in plant community (i.e., changing its composition and structure, and increasing the fuel load). As a consequence, we can expect differences in the resilience to fire as succession progresses. The aim of this work is to analyse the capacity of an ecosystem to return to pre-fire conditions as a function of the stage of abandonment of old agricultural lands. The study was carried out in the north of Alicante province (E Spain). In long-term abandoned lands, post-fire modulated plant response, which in turn determined soil crusting, runoff and erosion dynamics. In recently-abandoned lands, the plant community seemed less dependent on ratio to recover. Results show a large increase in soil surface crusting in the short term after the fire and it remained high at medium term in long-abandoned lands colonised by pine forest. Fire scarcely modified runoff and erosion in recently-abandoned lands whereas in forest lands the post-fire values increased by some orders of magnitude and remained highly dependent on rain characteristics in the short and medium term after the fire. The results obtained show evidence of increased vulnerability to fire in long-abandoned lands colonised by pine forests. (Author) 4 refs.

  20. Phosphorus in chronosequence of burnt sugar cane in Brazilian cerrado: humic acid analysis by {sup 31}P NMR; Fosforo em cronossequencia de cana-de-acucar queimada no cerrado goiano: analise de acidos humicos por RMN de {sup 31}P

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Celeste Q.; Pereira, Marcos G.; Garcia, Andreas C., E-mail: mgervasiopereira@gmail.com [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Dept. de Solos; Perin, Adriano; Gazolla, Paulo R. [Instituto Federal de Educacao, Ciencia e Tecnologia Goiano, Rio Verde, GO (Brazil); Gonzalez, Antonio P. [Universidade de Coruna, ES (Spain). Faculdad de Ciencias

    2013-10-01

    The aim of this study was to identify, with the use of {sup 31}P NMR spectroscopy, organic P species in humic acids (HA) in samples from Oxisol cultivated in chronosequence with sugar cane, pasture and Cerrado. The main forms of P-type found were orthophosphate, monoester-P (phosphate sugars) and P-diester (orthophosphate). The {sup 31}P NMR technique proved capable of identifying changes in the areas studied as a function of sugar cane burning time. In areas with 1 and 5 years of burnt cane, a decrease in recalcitrant organic P in humic acids indicated the need for use of P-humic substances for plant nutrition (author)

  1. CLIMATE CHANGE EFFECTS ON SPECIES COMPOSITION MEDIATES DECOMPOSITION IN AN OLD-FIELD ECOSYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Tyner, M.L.; Classen, A.T.

    2007-01-01

    Decomposition of leaf litter collected from an old-fi eld community grown under a combination of elevated atmospheric CO2 concentrations (+300ppm) and elevated surface temperature (+ 3.2°C) was examined in ambient conditions over 8 months in two separate experiments. In the fi rst experiment, we examined the main effects and interactions of CO2 and warming on litter quality and subsequent mass loss rates. Multi-species litter bags were constructed with litter collected from chambers with ambient CO2 and ambient temperatures (ACAT), elevated CO2 and elevated temperature (ECET), ambient CO2 and elevated temperature (ACET), and elevated CO2 and ambient temperature (ECAT). Litter collected from 6 species in each chamber was represented in decomposition bags in equal proportions. There were no differences in initial litter percent carbon (C) or nitrogen (N) among treatments. After 8 months, litter collected from ACET chambers lost over 20% more mass than litter collected from ECET or ACAT chambers, although biological differences were small. In the second experiment, we examined the indirect effect climate change may have on plant community composition, litter inputs, and subsequent mass loss rates. Litter bags were made from the same chambers mentioned above, but the amount of litter in the bag from each species was proportional to peak standing biomass of that species within the treatment. Initial litter in ECAT bags had up to 4% less C and 29% less N than ECET and ACET bags. Mass loss from ACET bags was 48% higher than mass loss from ECAT bags and 37% higher than mass loss from ACAT bags after 8 months of decomposition. These differences may have been driven by the higher proportion of litter from Lespedeza, a N-fi xer, in the natural ACET bags. Taken together, these data suggest that climate change will have a larger effect on decomposition by causing shifts in plant communities than it will by altering litter quality.

  2. Fire rehabilitation effectiveness: a chronosequence approach for the Great Basin

    Science.gov (United States)

    Pyke, David A.; Pilliod, David S.; Chambers, Jeanne C.; Brooks, Matthew L.; Grace, James

    2009-01-01

    Federal land management agencies have invested heavily in seeding vegetation for emergency stabilization and rehabilitation (ES&R) of non-forested lands. ES&R projects are implemented to reduce post-fire dominance of non-native annual grasses, minimize probability of recurrent fire, quickly recover lost habitat for sensitive species, and ultimately result in plant communities with desirable characteristics including resistance to invasive species and resilience or ability to recover following disturbance. Land managers lack scientific evidence to verify whether seeding non-forested lands achieves their desired long-term ES&R objectives. The overall objective of our investigation is to determine if ES&R projects increase perennial plant cover, improve community composition, decrease invasive annual plant cover and result in a more desirable fuel structure relative to no treatment following fires while potentially providing habitat for Greater Sage-Grouse, a species of management concern. In addition, we provide the locations and baseline vegetation data for further studies relating to ES&R project impacts. We examined effects of seeding treatments (drill and broadcast) vs. no seeding on biotic and abiotic (bare ground and litter) variables for the dominant climate regimes and ecological types within the Great Basin. We attempted to determine seeding effectiveness to provide desired plant species cover while restricting non-native annual grass cover relative to post-treatment precipitation, post-treatment grazing level and time-since-seeding. Seedings were randomly sampled from all known post-fire seedings that occurred in the four-state area of Idaho, Nevada, Oregon and Utah. Sampling locations were stratified by major land resource area, precipitation, and loam-dominated soils to ensure an adequate spread of locations to provide inference of our findings to similar lands throughout the Great Basin. Nearly 100 sites were located that contained an ES&R project. Of

  3. Dynamics of root and leaf decomposition in chronosequence of rubber plantation (Hevea brasilensis) in SW China

    International Nuclear Information System (INIS)

    Moazzam, N.S.; Yiping, Z.; Liqing, S.; Moazzam, N.S.

    2018-01-01

    This study highlighted the dynamics of stand parameters as well as root and leaf litter decomposition in the chronosequence (49, 32, 24 and 12 years old plantations established in the year 1965, 1982, 1990 and 2002) of the rubber plantation in Xishuangbanna SW China. Litter trappers were installed on the study site to collect the leaf litter and litter bag experiment was carried out to investigate the rate of root and leaf litter decomposition. The study revealed significant variation of stand characteristics during the decomposition process. The monthly litter fall and root biomass (all categories; kg m-3) showed positive correlation with stand characteristics and age. Remaining leaf litter mass % in the litter bags reduced with the passage of time and was significantly different in the chronosequence. The highest root decomposition rate (55%) was shown by fine roots and minimum (32%) by coarse roots during the study period. The investigations on elemental composition of the leaf and root provides basic important information for rate of nutrient cycle along with decomposition rate in rubber plantation and result are quite helpful for simulating the below ground carbon stock of rubber plantation in SW China. (author)

  4. Pedogenesis, geochemical forms of heavy metals, and artifact weathering in an urban soil chronosequence, Detroit, Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Howard, Jeffrey L., E-mail: jhoward@wayne.edu [Department of Geology, Wayne State University, Detroit, MI 48202 (United States); Olszewska, Dorota [Department of Geology, Wayne State University, Detroit, MI 48202 (United States)

    2011-03-15

    An urban soil chronosequence in downtown Detroit, MI was studied to determine the effects of time on pedogenesis and heavy metal sequestration. The soils developed in fill derived from mixed sandy and clayey diamicton parent materials on a level late Pleistocene lakebed plain under grass vegetation in a humid-temperate (mesic) climate. The chronosequence is comprised of soils in vacant lots (12 and 44 years old) and parks (96 and 120 years old), all located within 100 m of a roadway. An A-horizon 16 cm thick with 2% organic matter has developed after only 12 years of pedogenesis. The 12 year-old soil shows accelerated weathering of iron (e.g. nails) and cement artifacts attributed to corrosion by excess soluble salts of uncertain origin. Carbonate and Fe-oxide are immobilizing agents for heavy metals, hence it is recommended that drywall, plaster, cement and iron artifacts be left in soils at brownfield sites for their ameliorating effects. - Research highlights: > An A horizon has developed in these urban soils after only 12 years of pedogenesis. > Iron and cement artifacts have undergone accelerated weathering due to deicing salts. > One soil is contaminated by lead derived from weathered paint. > Artifact weathering can have ameliorating effects on urban soils contaminated by heavy metals. - Weathering of artifacts can have ameliorating effects on heavy metal-polluted soils at brownfield sites.

  5. Pedogenesis, geochemical forms of heavy metals, and artifact weathering in an urban soil chronosequence, Detroit, Michigan

    International Nuclear Information System (INIS)

    Howard, Jeffrey L.; Olszewska, Dorota

    2011-01-01

    An urban soil chronosequence in downtown Detroit, MI was studied to determine the effects of time on pedogenesis and heavy metal sequestration. The soils developed in fill derived from mixed sandy and clayey diamicton parent materials on a level late Pleistocene lakebed plain under grass vegetation in a humid-temperate (mesic) climate. The chronosequence is comprised of soils in vacant lots (12 and 44 years old) and parks (96 and 120 years old), all located within 100 m of a roadway. An A-horizon 16 cm thick with 2% organic matter has developed after only 12 years of pedogenesis. The 12 year-old soil shows accelerated weathering of iron (e.g. nails) and cement artifacts attributed to corrosion by excess soluble salts of uncertain origin. Carbonate and Fe-oxide are immobilizing agents for heavy metals, hence it is recommended that drywall, plaster, cement and iron artifacts be left in soils at brownfield sites for their ameliorating effects. - Research highlights: → An A horizon has developed in these urban soils after only 12 years of pedogenesis. → Iron and cement artifacts have undergone accelerated weathering due to deicing salts. → One soil is contaminated by lead derived from weathered paint. → Artifact weathering can have ameliorating effects on urban soils contaminated by heavy metals. - Weathering of artifacts can have ameliorating effects on heavy metal-polluted soils at brownfield sites.

  6. Successional patterns of key genes and processes involved in the microbial nitrogen cycle in a salt marsh chronosequence

    NARCIS (Netherlands)

    Salles, Joana Falcao; Cassia Pereira e Silva , de Michele; Dini-Andreote, Francisco; Dias, Armando C. F.; Guillaumaud, Nadine; Poly, Franck; van Elsas, Jan Dirk

    Here, we investigated the patterns of microbial nitrogen cycling communities along a chronosequence of soil development in a salt marsh. The focus was on the abundance and structure of genes involved in N fixation (nifH), bacterial and archaeal ammonium oxidation (amoA; AOB and AOA), and the

  7. Comparison of Red-Cockaded Woodpecker (Piciodes borealis) Nestling Diet in Old-Growth and Old-Field Longleaf Pine (Pinus palustris)

    Energy Technology Data Exchange (ETDEWEB)

    Hanula, J.L.; Engstrom, R.T.

    1999-10-01

    Automatic cameras were used to record adult woodpecker diets in old-growth and old-field longleaf pine in the South. Roaches were the number one prey for the woodpeckers based on either biomass or numbers. The latter ranged from 37% to 57% of the prey numbers and 55%-73% of the biomass. Morisita's index of similarity between old-field and old growth varied from 0.89 to 0.95. The authors conclude that the prey base is similar in both conditions and that old-growth provides similar foraging habitat.

  8. Variations in soil carbon dioxide efflux across a thaw slump chronosequence in northwestern Alaska

    International Nuclear Information System (INIS)

    Jensen, A E; Crosby, B T; Lohse, K A; Mora, C I

    2014-01-01

    Warming of the arctic landscape results in permafrost thaw, which causes ground subsidence or thermokarst. Thermokarst formation on hillslopes leads to the formation of thermal erosion features that dramatically alter soil properties and likely affect soil carbon emissions, but such features have received little study in this regard. In order to assess the magnitude and persistence of altered emissions, we use a space-for-time substitution (thaw slump chronosequence) to quantify and compare peak growing season soil carbon dioxide (CO 2 ) fluxes from undisturbed tundra, active, and stabilized thermal erosion features over two seasons. Measurements of soil temperature and moisture, soil organic matter, and bulk density are used to evaluate the factors controlling soil CO 2 emissions from each of the three chronosequence stages. Soil CO 2 efflux from the active slump is consistently less than half that observed in the undisturbed tundra or stabilized slump (1.8 versus 5.2 g CO 2 −C m −2  d −1 in 2011; 0.9 versus 3.2 g CO 2 −C m −2  d −1 in 2012), despite soil temperatures on the floor of the active slump that are 10–15  ° C warmer than the tundra and stabilized slump. Environmental factors such as soil temperature and moisture do not exert a strong control on CO 2 efflux, rather, local soil physical and chemical properties such as soil organic matter and bulk density, are strongly and inversely related among these chronosequence stages (r 2 = 0.97), and explain ∼50% of the variation in soil CO 2 efflux. Thus, despite profound soil warming and rapid exposure of buried carbon in the active slump, the low organic matter content, lack of stable vegetation, and large increases in the bulk densities in the uppermost portion of active slump soils (up to ∼2.2 g −1  cm −3 ) appear to limit CO 2 efflux from the active slump. Future studies should assess seasonal fluxes across these features and determine whether soil CO 2 fluxes from active

  9. How good a clock is rotation? The stellar rotation-mass-age relationship for old field stars

    International Nuclear Information System (INIS)

    Epstein, Courtney R.; Pinsonneault, Marc H.

    2014-01-01

    The rotation-mass-age relationship offers a promising avenue for measuring the ages of field stars, assuming the attendant uncertainties to this technique can be well characterized. We model stellar angular momentum evolution starting with a rotation distribution from open cluster M37. Our predicted rotation-mass-age relationship shows significant zero-point offsets compared to an alternative angular momentum loss law and published gyrochronology relations. Systematic errors at the 30% level are permitted by current data, highlighting the need for empirical guidance. We identify two fundamental sources of uncertainty that limit the precision of rotation-based ages and quantify their impact. Stars are born with a range of rotation rates, which leads to an age range at fixed rotation period. We find that the inherent ambiguity from the initial conditions is important for all young stars, and remains large for old stars below 0.6 M ☉ . Latitudinal surface differential rotation also introduces a minimum uncertainty into rotation period measurements and, by extension, rotation-based ages. Both models and the data from binary star systems 61 Cyg and α Cen demonstrate that latitudinal differential rotation is the limiting factor for rotation-based age precision among old field stars, inducing uncertainties at the ∼2 Gyr level. We also examine the relationship between variability amplitude, rotation period, and age. Existing ground-based surveys can detect field populations with ages as old as 1-2 Gyr, while space missions can detect stars as old as the Galactic disk. In comparison with other techniques for measuring the ages of lower main sequence stars, including geometric parallax and asteroseismology, rotation-based ages have the potential to be the most precise chronometer for 0.6-1.0 M ☉ stars.

  10. Biologic origin of iron nodules in a marine terrace chronosequence, Santa Cruz, California

    Science.gov (United States)

    Schulz, M.S.; Vivit, D.; Schulz, C.; Fitzpatrick, J.; White, A.

    2010-01-01

    The distribution, chemistry, and morphology of Fe nodules were studied in a marine terrace soil chronosequence northwest of Santa Cruz, California. The Fe nodules are found at depths hyphae throughout the nodules, including organic structures incorporating fine-grained Fe oxides. The fine-grained nature of the Fe oxides was substantiated by M??ssbauer spectroscopy. Our microscopic observations led to the hypothesis that the nodules in the Santa Cruz terrace soils are precipitated by fungi, perhaps as a strategy to sequester primary mineral grains for nutrient extraction. The fungal structures are fixed by the seasonal wetting and dry cycles and rounded through bioturbation. The organic structures are compacted by the degradation of fungal C with time. ?? Soil Science Society of America. All rights reserved.

  11. Seeding and planting upland oaks

    Science.gov (United States)

    1989-01-01

    Oaks can be planted or seeded in uplands to: (1) afforest old fields, strip-mined areas, or other areas devoid of trees, and (2) supplement natural reproduction within existing forests. Planting is usually more successful than direct seeding. But even under good conditions survival and growth of planted oak has been considerably poorer than with conifers and other...

  12. Ecosystem Development after Mangrove Wetland Creation: Plant-Soil Change across a 20-year Chronosequence

    Science.gov (United States)

    Mangrove wetland restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove wetland loss. However, ecosystem development and functional equivalence in restored and created mangrove wetlands is poorly understood. We compared a 20-yr chrono...

  13. The impact of biotic/abiotic interfaces in mineral nutrient cycling: A study of soils of the Santa Cruz chronosequence, California

    Science.gov (United States)

    White, A.F.; Schulz, M.S.; Vivit, D.V.; Bullen, T.D.; Fitzpatrick, J.

    2012-01-01

    Biotic/abiotic interactions between soil mineral nutrients and annual grassland vegetation are characterized for five soils in a marine terrace chronosequence near Santa Cruz, California. A Mediterranean climate, with wet winters and dry summers, controls the annual cycle of plant growth and litter decomposition, resulting in net above-ground productivities of 280-600gm -2yr -1. The biotic/abiotic (A/B) interface separates seasonally reversible nutrient gradients, reflecting biological cycling in the shallower soils, from downward chemical weathering gradients in the deeper soils. The A/B interface is pedologically defined by argillic clay horizons centered at soil depths of about one meter which intensify with soil age. Below these horizons, elevated solute Na/Ca, Mg/Ca and Sr/Ca ratios reflect plagioclase and smectite weathering along pore water flow paths. Above the A/B interface, lower cation ratios denote temporal variability due to seasonal plant nutrient uptake and litter leaching. Potassium and Ca exhibit no seasonal variability beneath the A/B interface, indicating closed nutrient cycling within the root zone, whereas Mg variability below the A/B interface denotes downward leakage resulting from higher inputs of marine aerosols and lower plant nutrient requirements.The fraction of a mineral nutrient annually cycled through the plants, compared to that lost from pore water discharge, is defined their respective fluxes F j,plants=q j,plants/(q j,plants+q j,discharge) with average values for K and Ca (F K,plants=0.99; F Ca,plants=0.93) much higher than for Mg and Na (F Mg,plants 0.64; F Na,plants=0.28). The discrimination against Rb and Sr by plants is described by fractionation factors (K Sr/Ca=0.86; K Rb/K=0.83) which are used in Rayleigh fractionation-mixing calculations to fit seasonal patterns in solute K and Ca cycling. K Rb/K and K24Mg/22Mg values (derived from isotope data in the literature) fall within fractionation envelopes bounded by inputs from

  14. Control of "blue carbon" storage by mangrove ageing: Evidence from a 66-year chronosequence in French Guiana.

    Science.gov (United States)

    Walcker, Romain; Gandois, Laure; Proisy, Christophe; Corenblit, Dov; Mougin, Éric; Laplanche, Christophe; Ray, Raghab; Fromard, François

    2018-06-01

    The role of mangroves in the blue carbon stock is critical and requires special focus. Mangroves are carbon-rich forests that are not in steady-state equilibrium at the decadal time scale. Over the last decades, the structure and zonation of mangroves have been largely disturbed by coastal changes and land use conversions. The amount of time since the last disturbance is a key parameter determining forest structure, but it has so far been overlooked in mangrove carbon stock projections. In particular, the carbon sequestration rates among mangrove successional ages after (re)establishment are poorly quantified and not used in large-scale estimations of the blue carbon stock. Here, it is hypothesized that ecosystem age structure significantly modulates mangrove carbon stocks. We analysed a 66-year chronosequence of the aboveground and belowground biomass and soil carbon stock of mangroves in French Guiana, and we found that in the year after forest establishment on newly formed mud banks, the aboveground, belowground and soil carbon stocks averaged 23.56 ± 7.71, 13.04 ± 3.37 and 84.26 ± 64.14 (to a depth of 1 m) Mg C/ha, respectively. The mean annual increment (MAI) in the aboveground and belowground reservoirs was 23.56 × Age -0.52 and 13.20 × Age -0.64  Mg C ha -1  year -1 , respectively, and the MAI in the soil carbon reservoir was 3.00 ± 1.80 Mg C ha -1  year -1 . Our results show that the plant carbon sink capacity declines with ecosystem age, while the soil carbon sequestration rate remains constant over many years. We suggest that global projections of the above- and belowground reservoirs of the carbon stock need to account for mangrove age structures, which result from historical changes in coastal morphology. Our work anticipates joint international efforts to globally quantify the multidecadal mangrove carbon balance based on the combined use of age-based parametric equations and time series of mangrove age maps at regional scales

  15. Measuring restoration progress using pore- and surface-water chemistry across a chronosequence of formerly afforested blanket bogs.

    Science.gov (United States)

    Gaffney, Paul P J; Hancock, Mark H; Taggart, Mark A; Andersen, Roxane

    2018-08-01

    During the restoration of degraded bogs and other peatlands, both habitat and functional recovery can be closely linked with nutrient cycling, which is reflected in pore- and surface-water chemistry. Several peatland restoration studies have shown that the time required for recovery of target conditions is slow (>10 years); for heavily-impacted, drained and afforested peatlands of northern Scotland, recovery time is unknown. We monitored pore- and surface-water chemistry across a chronosequence of formerly drained, afforested bog restoration sites spanning 0-17 years, using a space-for-time substitution, and compared them with open blanket bog control sites. Our aims were to measure rate of recovery towards bog conditions and to identify the best suite of water chemistry variables to indicate recovery. Our results show progress in recovery towards bog conditions over a 0-17 year period post-restoration. Elements scavenged by trees (Mg, Na, S) completely recovered within that period. Many water chemistry variables were affected by the restoration process itself, but recovered within 11 years, except ammonium (NH 4 + ), Zn and dissolved organic carbon (DOC) which remained elevated (when compared to control bogs) 17 years post restoration. Other variables did not completely recover (water table depth (WTD), pH), exhibiting what we term "legacy" effects of drainage and afforestation. Excess N and a lowered WTD are likely to slow the recovery of bog vegetation including key bog plants such as Sphagnum mosses. Over 17 years, we measured near-complete recovery in the chemistry of surface-water and deep pore-water but limited progress in shallow pore-water. Our results suggest that at least >17 years are required for complete recovery of water chemistry to bog conditions. However, we expect that newer restoration methods including conifer harvesting (stem plus brash) and the blocking of plough furrows (to increase the WTD) are likely to accelerate the restoration process

  16. Trace gas emissions from a chronosequence of bark beetle-infested lodgepole pine (Pinus contorta) forest stands

    Science.gov (United States)

    Norton, U.; Pendall, E.; Ewers, B. E.; Borkhuu, B.

    2011-12-01

    Severe outbreak of mountain pine beetle (MPB) and associated blue stain fungi have killed millions of hectares of coniferous forests in Western North America. This unprecedented disturbance has critically impacted ecosystem biogeochemistry and net carbon (C) and nitrogen (N) fluxes. However, the effects on greenhouse gas (GHG) emissions and drivers of biogeochemical processes that trigger GHG emissions following MPB infestations are not well understood. Such information can help assess regional-level changes in ecosystem C and N budgets and large-scale disturbance impacts on gas exchange between the atmosphere and terrestrial ecosystem. The overall objective of this research was to assess the immediate responses of GHG fluxes and soil C and N mineralization rates along a chronosequence of recently infested (1-yr, 3-yr and 4-yr ago) and uninfested (150-yr, 20-yr and 15-yr old) lodgepole pine stands in Medicine Bow National Forest in southeastern Wyoming. We hypothesize that MPB-induced tree mortality significantly changes stand-level hydrology, soil organic matter quality and chemistry of aboveground and belowground plant inputs. Consequently, these modifications influence nitrous oxide (N2O) emissions and methane (CH4) assimilation. Biweekly GHG measurements using static chambers were carried out during three consecutive snow-free growing seasons. Our results suggest that a stand infested within a year already shows a 20% increase in spring N2O production and a small decline in summer CH4 assimilation when compared to uninfested stands. Stands infested three and four years prior to our measurements produce over three times more N2O and assimilate three to five times less CH4 when compared to uninfested stands. In addition, a notable increase in soil moisture content and soil mineral N concentrations following early onset of the MPB infestation was also observed. An overall increase in N2O production and decline in CH4 assimilation following MPB infestation may

  17. Soil microbial succession along a chronosequence on a High Arctic glacier foreland, Ny-Ålesund, Svalbard: 10 years' change

    Science.gov (United States)

    Yoshitake, Shinpei; Uchida, Masaki; Iimura, Yasuo; Ohtsuka, Toshiyuki; Nakatsubo, Takayuki

    2018-06-01

    Rapid glacial retreat in the High Arctic causes the expansion of new habitats, but the successional trajectories of soil microbial communities are not fully understood. We examined microbial succession along a chronosequence twice with a 10-year interval in a High Arctic glacier foreland. Soil samples were collected from five study sites with different ages and phospholipid fatty acids analysis was conducted to investigate the microbial biomass and community structure. Microbial biomass did not differ significantly between the two sampling times but tended to increase with the chronosequence and showed a significant correlation with soil carbon (C) and nitrogen (N) content. Microbial community structure clearly differed along the chronosequence and was correlated with C and N content. The largest shift in community structure over 10 years was observed in the newly exposed sites after deglaciation. The accumulation of soil organic matter was regarded as an important determinant both of microbial biomass and community structure over the successional period. In contrast, the initial microbial community on the newly exposed soil changed rapidly even in the High Arctic, suggesting that some key soil processes such as C and N cycling can also shift within the relatively short period after rapid glacial retreat.

  18. Facilitative and Inhibitory Effect of Litter on Seedling Emergence and Early Growth of Six Herbaceous Species in an Early Successional Old Field Ecosystem

    Directory of Open Access Journals (Sweden)

    Qiang Li

    2014-01-01

    Full Text Available In the current study, a field experiment was conducted to examine effects of litter on seedling emergence and early growth of four dominant weed species from the early successional stages of old field ecosystem and two perennial grassland species in late successional stages. Our results showed that increased litter cover decreased soil temperature and temperature variability over time and improved soil moisture status. Surface soil electrical conductivity increased as litter increased. The increased litter delayed seedling emergence time and rate. The emergence percentage of seedlings and establishment success rate firstly increased then decreased as litter cover increased. When litter biomass was below 600 g m−2, litter increased seedlings emergence and establishment success in all species. With litter increasing, the basal diameter of seedling decreased, but seedling height increased. Increasing amounts of litter tended to increase seedling dry weight and stem leaf ratio. Different species responded differently to the increase of litter. Puccinellia tenuiflora and Chloris virgata will acquire more emergence benefits under high litter amount. It is predicted that Chloris virgata will dominate further in this natural succession old field ecosystem with litter accumulation. Artificial P. tenuiflora seeds addition may be required to accelerate old field succession toward matured grassland.

  19. Facilitative and inhibitory effect of litter on seedling emergence and early growth of six herbaceous species in an early successional old field ecosystem.

    Science.gov (United States)

    Li, Qiang; Yu, Pujia; Chen, Xiaoying; Li, Guangdi; Zhou, Daowei; Zheng, Wei

    2014-01-01

    In the current study, a field experiment was conducted to examine effects of litter on seedling emergence and early growth of four dominant weed species from the early successional stages of old field ecosystem and two perennial grassland species in late successional stages. Our results showed that increased litter cover decreased soil temperature and temperature variability over time and improved soil moisture status. Surface soil electrical conductivity increased as litter increased. The increased litter delayed seedling emergence time and rate. The emergence percentage of seedlings and establishment success rate firstly increased then decreased as litter cover increased. When litter biomass was below 600 g m(-2), litter increased seedlings emergence and establishment success in all species. With litter increasing, the basal diameter of seedling decreased, but seedling height increased. Increasing amounts of litter tended to increase seedling dry weight and stem leaf ratio. Different species responded differently to the increase of litter. Puccinellia tenuiflora and Chloris virgata will acquire more emergence benefits under high litter amount. It is predicted that Chloris virgata will dominate further in this natural succession old field ecosystem with litter accumulation. Artificial P. tenuiflora seeds addition may be required to accelerate old field succession toward matured grassland.

  20. Strategies for soil quality assessment using VNIR gyperspectral spectroscopy in a western Kenya Chronosequence

    Science.gov (United States)

    Kinoshita, Rintaro; Moebius-Clune, Bianca N.; van Es, Harold M.; Hively, W. Dean; Bilgilis, A. Volkan

    2012-01-01

    Visible and near-infrared reflectance spectroscopy (VNIRS) is a rapid and nondestructive method that can predict multiple soil properties simultaneously, but its application in multidimensional soil quality (SQ) assessment in the tropics still needs to be further assessed. In this study, VNIRS (350–2500 nm) was employed to analyze 227 air-dried soil samples of Ultisols from a soil chronosequence in western Kenya and assess 16 SQ indicators. Partial least squares regression (PLSR) was validated using the full-site cross-validation method by grouping samples from each farm or forest site. Most suitable models successfully predicted SQ indicators (R2 ≥ 0.80; ratio of performance to deviation [RPD] ≥ 2.00) including soil organic matter (OMLOI), active C, Ca, cation exchange capacity (CEC), and clay. Moderately-well predicted indicators (0.50 ≤ R2 pwp), and field capacity (Θfc). Poorly predicted indicators (R2 < 0.50; RPD < 1.40) were EC, S, P, available water capacity (AWC), K, Zn, and penetration resistance. Combining VNIRS with selected field- and laboratory-measured SQ indicator values increased predictability. Furthermore, VNIRS showed moderate to substantial agreement in predicting interpretive SQ scores and a composite soil quality index (CSQI) especially when combined with directly measured SQ indicator values. In conclusion, VNIRS has good potential for low cost, rapid assessment of physical and biological SQ indicators but conventional soil chemical tests may need to be retained to provide comprehensive SQ assessments.

  1. Effect of home construction on soil carbon storage-A chronosequence case study.

    Science.gov (United States)

    Majidzadeh, Hamed; Lockaby, B Graeme; Governo, Robin

    2017-07-01

    Urbanization results in the rapid expansion of impervious surfaces, therefore a better understanding of biogeochemical consequences of soil sealing is crucial. Previous research documents a significant reduction in soil carbon and nitrogen content, however, it is unclear if this decrease is a result of top soil removal or long-term soil sealing. In this study, soil biogeochemical properties were quantified beneath homes built on a crawl space at two depths (0-10 cm, and 10-20 cm). All homes, 11-114 years in age, were sampled in the Piedmont region of Alabama and Georgia, USA. This age range enabled the use of a chronosequence approach to estimate carbon loss or gain under the sampled homes. The difference in soil carbon content beneath homes and adjoining urban lawns showed a quadratic relation with age. Maximum C loss occurred at approximately fifty years. The same pattern was observed for MBC: C ratio suggesting that the soil carbon content was decreasing beneath the homes for first fifty years, then increased afterward. The average soil C and N content in the top 10 cm were respectively 61.86% (±4.42%), and 65.77% (±5.65%) lower underneath the homes in comparison to urban lawns. Microbial biomass carbon (MBC), and nitrogen (MBN) were significantly lower below the homes compared to the urban lawns, while bulk density and phosphorus content were higher beneath the homes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Variation of Soil Bacterial Communities in a Chronosequence of Rubber Tree (Hevea brasiliensis Plantations

    Directory of Open Access Journals (Sweden)

    Yu-Jie Zhou

    2017-05-01

    Full Text Available Regarding rubber tree plantations, researchers lack a basic understanding of soil microbial communities; specifically, little is known about whether or not soil microbial variation is correlated with succession in these plantations. In this paper, we used high-throughput sequencing of the 16S rRNA gene to investigate the diversity and composition of the soil bacterial communities in a chronosequence of rubber tree plantations that were 5, 10, 13, 18, 25, and 30 years old. We determined that: (1 Soil bacterial diversity and composition show changes over the succession stages of rubber tree plantations. The diversity of soil bacteria were highest in 10, 13, and 18 year-old rubber tree plantations, followed by 30 year-old rubber tree plantations, whereas 5 and 25 year-old rubber tree plantations had the lowest values for diversity. A total of 438,870 16S rDNA sequences were detected in 18 soil samples from six rubber tree plantations, found in 28 phyla, 66 classes, 139 orders, 245 families, 355 genera, and 645 species, with 1.01% sequences from unclassified bacteria. The dominant phyla were Acidobacteria, Proteobacteria, Chloroflexi, Actinobacteria, and Verrucomicrobia (relative abundance large than 3%. There were differences in soil bacterial communities among different succession stages of rubber tree plantation. (2 Soil bacteria diversity and composition in the different stages was closely related to pH, vegetation, soil nutrient, and altitude, of which pH, and vegetation were the main drivers.

  3. Fractionation, transfer, and ecological risks of heavy metals in riparian and ditch wetlands across a 100-year chronosequence of reclamation in an estuary of China

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Rong [State Key Laboratory of Water Environment Stimulation, School of Environment, Beijing Normal University, Beijing 100875 (China); School of Nature Conservation, Beijing Forestry University, Beijing 100083 (China); Bai, Junhong, E-mail: junhongbai@163.com [State Key Laboratory of Water Environment Stimulation, School of Environment, Beijing Normal University, Beijing 100875 (China); Lu, Qiongqiong; Zhao, Qingqing; Gao, Zhaoqin; Wen, Xiaojun; Liu, Xinhui [State Key Laboratory of Water Environment Stimulation, School of Environment, Beijing Normal University, Beijing 100875 (China)

    2015-06-01

    The effect of reclamation on heavy metal concentrations and the ecological risks in ditch wetlands (DWs) and riparian wetlands (RWs) across a 100-year chronosequence in the Pearl River Estuary of China was investigated. Concentrations of 4 heavy metals (Cd, Cu, Pb, and Zn) in soil and plant samples, and sequential extracts of soil samples were determined, using inductively coupled plasma atomic absorption spectrometry. Results showed that heavy metal concentrations were higher in older DW soils than in the younger ones, and that the younger RW soils contained higher heavy metal concentrations compared to the older ones. Although the increasing tendency of heavy metal concentrations in soil was obvious after wetland reclamation, the metals Cu, Pb, and Zn exhibited low or no risks to the environment based on the risk assessment code (RAC). Cd, on the other hand, posed a medium or high risk. Cd, Pb, and Zn were mainly bound to Fe–Mn oxide, whereas most of Cu remained in the residual phase in both ditch and riparian wetland soils, and the residual proportions generally increased with depth. Bioconcentration and translocation factors for most of these four heavy metals significantly decreased in the DWs with older age (p < 0.05), whereas they increased in the RWs with younger age (p < 0.05). The DW soils contained higher concentrations of heavy metals in the organic fractions, whereas there were more carbonate and residual fractions in the RW soils. The non-bioavailable fractions of Cu and Zn, and the organic-bound Cd and Pb significantly inhibited plant growth. - Highlights: • Heavy metals in ditch wetland accumulated with increasing reclamation history. • Heavy metals exist in the Fe–Mn oxides and residual fractions in both wetlands. • Cd posed a medium to high environmental risk while low risk for other metals. • Long reclamation history caused lower BCFs and TFs in DWs and higher levels in RWs. • RW soils contained more heavy metals in the carbonate

  4. Fractionation, transfer, and ecological risks of heavy metals in riparian and ditch wetlands across a 100-year chronosequence of reclamation in an estuary of China

    International Nuclear Information System (INIS)

    Xiao, Rong; Bai, Junhong; Lu, Qiongqiong; Zhao, Qingqing; Gao, Zhaoqin; Wen, Xiaojun; Liu, Xinhui

    2015-01-01

    The effect of reclamation on heavy metal concentrations and the ecological risks in ditch wetlands (DWs) and riparian wetlands (RWs) across a 100-year chronosequence in the Pearl River Estuary of China was investigated. Concentrations of 4 heavy metals (Cd, Cu, Pb, and Zn) in soil and plant samples, and sequential extracts of soil samples were determined, using inductively coupled plasma atomic absorption spectrometry. Results showed that heavy metal concentrations were higher in older DW soils than in the younger ones, and that the younger RW soils contained higher heavy metal concentrations compared to the older ones. Although the increasing tendency of heavy metal concentrations in soil was obvious after wetland reclamation, the metals Cu, Pb, and Zn exhibited low or no risks to the environment based on the risk assessment code (RAC). Cd, on the other hand, posed a medium or high risk. Cd, Pb, and Zn were mainly bound to Fe–Mn oxide, whereas most of Cu remained in the residual phase in both ditch and riparian wetland soils, and the residual proportions generally increased with depth. Bioconcentration and translocation factors for most of these four heavy metals significantly decreased in the DWs with older age (p < 0.05), whereas they increased in the RWs with younger age (p < 0.05). The DW soils contained higher concentrations of heavy metals in the organic fractions, whereas there were more carbonate and residual fractions in the RW soils. The non-bioavailable fractions of Cu and Zn, and the organic-bound Cd and Pb significantly inhibited plant growth. - Highlights: • Heavy metals in ditch wetland accumulated with increasing reclamation history. • Heavy metals exist in the Fe–Mn oxides and residual fractions in both wetlands. • Cd posed a medium to high environmental risk while low risk for other metals. • Long reclamation history caused lower BCFs and TFs in DWs and higher levels in RWs. • RW soils contained more heavy metals in the carbonate

  5. Organic horizon and mineral soil mercury along three clear-cut forest chronosequences across the northeastern USA.

    Science.gov (United States)

    Richardson, Justin B; Petrenko, Chelsea L; Friedland, Andrew J

    2017-12-01

    Mercury (Hg) is a globally distributed pollutant trace metal that has been increasing in terrestrial environments due to rising anthropogenic emissions. Vegetation plays an important role in Hg sequestration in forested environments, but increasing tree removal for biofuels and wood products may affect this process. The long-term effect of clear-cutting on forest soil Hg remains uncertain, since most studies are limited to measuring changes for event. The chronosequence approach, which substitutes space for time using forest stands of different ages since clear-cutting, allows for investigation of processes occurring over decades to centuries. Here, we utilized three clear-cut forest soil chronosequences across the northeastern USA to understand Hg accumulation and retention over several decades. Total Hg concentrations and pools were quantified for five soil depth increments along three chronosequences. Our results showed Hg concentrations and pools decreased in the initial 20 years following clear-cutting. Mineral soil Hg pools decreased 21-53% (7-14 mg m -2 ) between 1-5-year-old stands and 15-25-year-old stands but mineral soil Hg pools recovered in 55-140-year-old stands to similar values as measured in 1-5-year-old stands. Our study is one of the first to demonstrate a decrease and recovery in Hg pool size. These changes in Hg did not correspond with changes in bulk density, soil C, or pH. We utilized a simple two-box model to determine how different Hg fluxes affected organic and mineral soil horizon Hg pools. Our simple model suggests that changes in litterfall and volatilization rates could have caused the observed changes in organic horizon Hg pools. However, only increases in leaching could reproduce observed decreases to mineral soil Hg pools. Further studies are needed to determine the mechanism of Hg loss from forest soils following clear-cutting.

  6. Soil development along a glacial chronosequence (Pré de Bar glacier, NW Italy)

    Science.gov (United States)

    Letey, Stéphanie; Freppaz, Michele; Filippa, Gianluca; Stanchi, Silvia; Cerli, Chiara; Pogliotti, Paolo; Zanini, Ermanno

    2010-05-01

    After the maximum expansion phase of the Little Ice Age, soils located in proglacial areas in the Italian Alps evolved over a time span of about 190 years. In the future, as a consequence of climate change, additional areas will become ice-free and therefore subject to pedogenesis. In such conditions, ice retreat time and topography are expected to play a major role among soil formation factors. Due to extreme environmental characteristics, soil evolution will be rather slow, and heavily influenced by severe soil loss phenomena (e.g. water erosion due to extreme rainfall event and snowmelt, avalanche erosion). We investigated the soil formation along a glacial chronosequence of an Alpine glacier foreland. The Pré de Bar glacier is located in North West Italy (Aosta Valley Region), in the Mont Blanc massif, between 3750 and 2150 m a.s.l. and it covers an area of 340 ha. The glacier was chosen because of the availability of old photographs documenting the glacier retreat phases starting from 1820. At the present time, the cumulative retreat length of the Pré de Bar glacier has reached 1600 m. Along this length, sampling sites were established at 6 successional stages from 6 to 189 years since deglaciation, from 2100 to 1880 m a.s.l.. Soil profiles were opened and sampled according to diagnostic horizons, then they were characterized by means of standard chemical and physical methods. Moreover, as recently deglaciated soils, characterized by incipient pedogenesis, may be particularly vulnerable from the physical point of view, the Atterberg Limits (LL, Liquid Limit; and PL, Plastic Limit) and the WAS (Water Aggregate Stability) index were determined, as indicators of soil physical quality. Soil samples were also subjected to organic matter density fractionation to assess the role of organic C in structure development. All the analyzed soils were classified as Lythic Cryorthents (higher elevation) or Typic Cryorthents (lower elevation) (USDA - Soil Taxonomy), with

  7. Downward carbon transport in a 2000-year rice paddy soil chronosequence traced by radiocarbon measurements

    Energy Technology Data Exchange (ETDEWEB)

    Braeuer, T., E-mail: tbraeuer@leibniz.uni-kiel.de [Leibniz-Laboratory, Christian-Albrechts-University, Kiel (Germany); Grootes, P.M.; Nadeau, M.-J.; Andersen, N. [Leibniz-Laboratory, Christian-Albrechts-University, Kiel (Germany)

    2013-01-15

    Paddy and non-paddy soils from a chronosequence of 50-2000 years of agricultural use, developed on former estuarine sediments of the Yangtze River, were sampled near Cixi, Zhejiang Province, China, in the framework of the Research Unit 'Biogeochemistry of paddy soil evolution' of the German Research Foundation (DFG). In addition samples of Yangtze River estuarine sediments were obtained. The parent sediment shows a fairly homogeneous composition with ca. 0.3% TOC and a {sup 14}C concentration of ca. 50 pMC. After being diked-in, gradients in soil organic carbon and {sup 14}C concentration develop under the influence of vegetation and cultivation. In the non-paddy soil, a {sup 14}C gradient with concentration decreasing with increasing depth from modern (>100 pMC) to original sediment values around 50 pMC is already established after 50 years and can also be observed in the older sites. In contrast, the 50 years old paddy soil shows organic carbon and {sup 14}C enrichment only in the A-horizon and a nearly constant TOC and {sup 14}C stock of original sediment below the plough pan. To test the basic approach that the soil profile development started on homogeneous sediment, an isotope and mass balance calculation was used. The results show a quite similar age composition of different sample sites. Paddy rice cultivation quickly leads to a dense plough pan, which seriously reduces, but not totally prevents, downward transport of organic matter. The equilibrium times for TOC and {sup 14}C in paddy soil profiles are short (decades) in the topsoil and in the order of centuries in the subsoil, underlining the dynamic character of soil organic carbon.

  8. Downward carbon transport in a 2000-year rice paddy soil chronosequence traced by radiocarbon measurements

    International Nuclear Information System (INIS)

    Bräuer, T.; Grootes, P.M.; Nadeau, M.-J.; Andersen, N.

    2013-01-01

    Paddy and non-paddy soils from a chronosequence of 50–2000 years of agricultural use, developed on former estuarine sediments of the Yangtze River, were sampled near Cixi, Zhejiang Province, China, in the framework of the Research Unit “Biogeochemistry of paddy soil evolution” of the German Research Foundation (DFG). In addition samples of Yangtze River estuarine sediments were obtained. The parent sediment shows a fairly homogeneous composition with ca. 0.3% TOC and a 14 C concentration of ca. 50 pMC. After being diked-in, gradients in soil organic carbon and 14 C concentration develop under the influence of vegetation and cultivation. In the non-paddy soil, a 14 C gradient with concentration decreasing with increasing depth from modern (>100 pMC) to original sediment values around 50 pMC is already established after 50 years and can also be observed in the older sites. In contrast, the 50 years old paddy soil shows organic carbon and 14 C enrichment only in the A-horizon and a nearly constant TOC and 14 C stock of original sediment below the plough pan. To test the basic approach that the soil profile development started on homogeneous sediment, an isotope and mass balance calculation was used. The results show a quite similar age composition of different sample sites. Paddy rice cultivation quickly leads to a dense plough pan, which seriously reduces, but not totally prevents, downward transport of organic matter. The equilibrium times for TOC and 14 C in paddy soil profiles are short (decades) in the topsoil and in the order of centuries in the subsoil, underlining the dynamic character of soil organic carbon.

  9. Soil surface CO2 flux in a boreal black spruce fire chronosequence

    Science.gov (United States)

    Wang, Chuankuan; Bond-Lamberty, Ben; Gower, Stith T.

    2003-02-01

    Understanding the effects of wildfire on the carbon (C) cycle of boreal forests is essential to quantifying the role of boreal forests in the global carbon cycle. Soil surface CO2 flux (Rs), the second largest C flux in boreal forests, is directly and indirectly affected by fire and is hypothesized to change during forest succession following fire. The overall objective of this study was to measure and model Rs for a black spruce (Picea mariana [Mill.] BSP) postfire chronosequence in northern Manitoba, Canada. The experiment design was a nested factorial that included two soil drainage classes (well and poorly drained) × seven postfire aged stands. Specific objectives were (1) to quantify the relationship between Rs and soil temperature for different aged boreal black spruce forests in well-drained and poorly drained soil conditions, (2) to examine Rs dynamics along postfire successional stands, and (3) to estimate annual soil surface CO2 flux for these ecosystems. Soil surface CO2 flux was significantly affected by soil drainage class (p = 0.014) and stand age (p = 0.006). Soil surface CO2 flux was positively correlated to soil temperature (R2 = 0.78, p aged stand combination. Soil surface CO2 flux was significantly greater at the well-drained than the poorly drained stands (p = 0.007) during growing season. Annual soil surface CO2 flux for the 1998, 1995, 1989, 1981, 1964, 1930, and 1870 burned stands averaged 226, 412, 357, 413, 350, 274, and 244 g C m-2 yr-1 in the well-drained stands and 146, 380, 300, 303, 256, 233, and 264 g C m-2 yr-1 in the poorly drained stands. Soil surface CO2 flux during the winter (from 1 November to 30 April) comprised from 5 to 19% of the total annual Rs. We speculate that the smaller soil surface CO2 flux in the recently burned than the older stands is mainly caused by decreased root respiration.

  10. Soil functional diversity analysis of a bauxite-mined restoration chronosequence.

    Science.gov (United States)

    Lewis, Dawn E; White, John R; Wafula, Denis; Athar, Rana; Dickerson, Tamar; Williams, Henry N; Chauhan, Ashvini

    2010-05-01

    Soil microorganisms are sensitive to environmental perturbations such that changes in microbial community structure and function can provide early signs of anthropogenic disturbances and even predict restoration success. We evaluated the bacterial functional diversity of un-mined and three chronosequence sites at various stages of rehabilitation (0, 10, and 20 years old) located in the Mocho Mountains of Jamaica. Samples were collected during the dry and wet seasons and analyzed for metal concentrations, microbial biomass carbon, bacterial numbers, and functional responses of soil microbiota using community-level physiological profile (CLPP) assays. Regardless of the season, un-mined soils consisted of higher microbial biomass and numbers than any of the rehabilitated sites. Additionally, the number and rate of substrates utilized and substrate evenness (the distribution of color development between the substrates) were significantly greater in the un-mined soils with carbohydrates being preferentially utilized than amino acids, polymers, carboxylic acids, and esters. To some extent, functional responses varied with the seasons but the least physiological activity was shown by the site rehabilitated in 1987 indicating long-term perturbation to this ecosystem. Small subunit ribosomal DNA (SSUrDNA)-denaturing gradient-gel electrophoresis analyses on the microbiota collected from the most preferred CLPP substrates followed by taxonomic analyses showed Proteobacteria, specifically the gamma-proteobacteria, as the most functionally active phyla, indicating a propensity of this phyla to out-compete other groups under the prevailing conditions. Additionally, multivariate statistical analyses, Shannon's diversity, and evenness indices, principal component analysis, biplot and un-weighted-pair-group method with arithmetic averages dendrograms further confirmed that un-mined sites were distinctly different from the rehabilitated soils.

  11. Edaphic, salinity, and stand structural trends in chronosequences of native and non-native dominated riparian forests along the Colorado River, USA

    Science.gov (United States)

    Merritt, David M.; Shafroth, Patrick B.

    2012-01-01

    Tamarix spp. are introduced shrubs that have become among the most abundant woody plants growing along western North American rivers. We sought to empirically test the long-held belief that Tamarix actively displaces native species through elevating soil salinity via salt exudation. We measured chemical and physical attributes of soils (e.g., salinity, major cations and anions, texture), litter cover and depth, and stand structure along chronosequences dominated by Tamarix and those dominated by native riparian species (Populus or Salix) along the upper and lower Colorado River in Colorado and Arizona/California, USA. We tested four hypotheses: (1) the rate of salt accumulation in soils is faster in Tamarix-dominated stands than stands dominated by native species, (2) the concentration of salts in the soil is higher in mature stands dominated by Tamarix compared to native stands, (3) soil salinity is a function of Tamarix abundance, and (4) available nutrients are more concentrated in native-dominated stands compared to Tamarix-dominated stands. We found that salt concentration increases at a faster rate in Tamarix-dominated stands along the relatively free-flowing upper Colorado but not along the heavily-regulated lower Colorado. Concentrations of ions that are known to be preferentially exuded by Tamarix (e.g., B, Na, and Cl) were higher in Tamarix stands than in native stands. Soil salt concentrations in older Tamarix stands along the upper Colorado were sufficiently high to inhibit germination, establishment, or growth of some native species. On the lower Colorado, salinity was very high in all stands and is likely due to factors associated with floodplain development and the hydrologic effects of river regulation, such as reduced overbank flooding, evaporation of shallow ground water, higher salt concentrations in surface and ground water due to agricultural practices, and higher salt concentrations in fine-textured sediments derived from naturally saline

  12. Carbon accumulation and changes in soil chemistry in reclaimed open-cast coal mining heaps near Sokolov using repeated measurement of chronosequence sites

    Czech Academy of Sciences Publication Activity Database

    Bartuška, Martin; Frouz, J.

    2015-01-01

    Roč. 66, 1 /SI/ (2015), s. 104-111 ISSN 1351-0754 Grant - others:GA ČR(CZ) GAP504/12/1288 Program:GA Institutional support: RVO:60077344 Keywords : carbon accumulation * changes in soil chemistry * post mining sites * chronosequence Subject RIV: DF - Soil Science Impact factor: 3.425, year: 2015

  13. Soil Chemical Weathering and Nutrient Budgets along an Earthworm Invasion Chronosequence in a Northern Minnesota Forest

    Science.gov (United States)

    Resner, K. E.; Yoo, K.; Sebestyen, S. D.; Aufdenkampe, A. K.; Lyttle, A.; Weinman, B. A.; Blum, A.; Hale, C. M.

    2011-12-01

    We are investigating the impact of exotic earthworms on the rate of nutrient and ion release from soil chemical weathering along an ~200 m invasion chronosequence in a northern Minnesota sugar maple forest. The earthworms belong to three ecological groups that represent different feeding and burrowing behaviors, all of which were introduced from Europe to the previously earthworm-free Great Lakes Region through fishing and agricultural activities. As earthworms digest and mix the soil, we hypothesize that they significantly alter chemical weathering processes by incorporating mineral surfaces to new geochemical environments in their intestines and at different soil depths. The effect of mixing on soil morphology is dramatic, but biogeochemical changes remain largely unknown and therefore are poorly coupled to the current and potential changes in forest ecosystems under the threat of exotic earthworms. We analyze the activities of short-lived isotopes 137-Cs and 210-Pb along with the inorganic chemistry of soil, water, and leaf litter across an invasion transect and link these measurements to the biomass and species composition of exotic earthworms. Earthworms vertically relocate minerals and organic matter largely within the top ~10 cm, which is reflected in the depth profiles of the short-lived isotopes. Among the inorganic nutrients analyzed, Ca is of particular interest due to sugar maple's aptitude for recycling Ca. Fractional mass loss values (tau) of Ca, relative to the soil's parent material, show an enrichment factor of 14 in the least invaded A horizon soils. However, such a high enrichment factor declines dramatically in the heavily invaded soils, suggesting that earthworm activities contribute to leaching Ca. In contrast, the enrichment factor of Fe increases with greater degrees of earthworm invasion, which is consistent with the extraction chemistry data showing greater quantities of pedogenic crystalline iron oxides and greater mineral specific

  14. Intra- versus inter-site macroscale variation in biogeochemical properties along a paddy soil chronosequence

    Directory of Open Access Journals (Sweden)

    C. Mueller-Niggemann

    2012-03-01

    Full Text Available In order to assess the intrinsic heterogeneity of paddy soils, a set of biogeochemical soil parameters was investigated in five field replicates of seven paddy fields (50, 100, 300, 500, 700, 1000, and 2000 yr of wetland rice cultivation, one flooded paddy nursery, one tidal wetland (TW, and one freshwater site (FW from a coastal area at Hangzhou Bay, Zhejiang Province, China. All soils evolved from a marine tidal flat substrate due to land reclamation. The biogeochemical parameters based on their properties were differentiated into (i a group behaving conservatively (TC, TOC, TN, TS, magnetic susceptibility, soil lightness and colour parameters, δ13C, δ15N, lipids and n-alkanes and (ii one encompassing more labile properties or fast cycling components (Nmic, Cmic, nitrate, ammonium, DON and DOC. The macroscale heterogeneity in paddy soils was assessed by evaluating intra- versus inter-site spatial variability of biogeochemical properties using statistical data analysis (descriptive, explorative and non-parametric. Results show that the intrinsic heterogeneity of paddy soil organic and minerogenic components per field is smaller than between study sites. The coefficient of variation (CV values of conservative parameters varied in a low range (10% to 20%, decreasing from younger towards older paddy soils. This indicates a declining variability of soil biogeochemical properties in longer used cropping sites according to progress in soil evolution. A generally higher variation of CV values (>20–40% observed for labile parameters implies a need for substantially higher sampling frequency when investigating these as compared to more conservative parameters. Since the representativeness of the sampling strategy could be sufficiently demonstrated, an investigation of long-term carbon accumulation/sequestration trends in topsoils of the 2000 yr paddy chronosequence under wetland rice cultivation

  15. Effect of home construction on soil carbon storage-A chronosequence case study

    International Nuclear Information System (INIS)

    Majidzadeh, Hamed; Lockaby, B. Graeme; Governo, Robin

    2017-01-01

    Urbanization results in the rapid expansion of impervious surfaces, therefore a better understanding of biogeochemical consequences of soil sealing is crucial. Previous research documents a significant reduction in soil carbon and nitrogen content, however, it is unclear if this decrease is a result of top soil removal or long-term soil sealing. In this study, soil biogeochemical properties were quantified beneath homes built on a crawl space at two depths (0–10 cm, and 10–20 cm). All homes, 11–114 years in age, were sampled in the Piedmont region of Alabama and Georgia, USA. This age range enabled the use of a chronosequence approach to estimate carbon loss or gain under the sampled homes. The difference in soil carbon content beneath homes and adjoining urban lawns showed a quadratic relation with age. Maximum C loss occurred at approximately fifty years. The same pattern was observed for MBC: C ratio suggesting that the soil carbon content was decreasing beneath the homes for first fifty years, then increased afterward. The average soil C and N content in the top 10 cm were respectively 61.86% (±4.42%), and 65.77% (±5.65%) lower underneath the homes in comparison to urban lawns. Microbial biomass carbon (MBC), and nitrogen (MBN) were significantly lower below the homes compared to the urban lawns, while bulk density and phosphorus content were higher beneath the homes. - Highlights: • The average soil carbon and nitrogen content decreased by 61.86 %, and 65.77 % underneath the homes in top 10 cm. • Soils beneath the homes are a source of carbon loss for approximately first fifty years. • After age fifty carbon sequestration becomes the dominant process underneath the homes. • Top soil removal and initial disturbance account for a major portion of carbon loss beneath the impervious surfaces. • Average microbial biomass carbon and nitrogen in top 10 cm decreased 65.14 % and 80.51 % respectively beneath the homes. - Soil carbon content in top

  16. Litter and dead wood dynamics in ponderosa pine forests along a 160-year chronosequence.

    Science.gov (United States)

    Hall, S A; Burke, I C; Hobbs, N T

    2006-12-01

    Disturbances such as fire play a key role in controlling ecosystem structure. In fire-prone forests, organic detritus comprises a large pool of carbon and can control the frequency and intensity of fire. The ponderosa pine forests of the Colorado Front Range, USA, where fire has been suppressed for a century, provide an ideal system for studying the long-term dynamics of detrital pools. Our objectives were (1) to quantify the long-term temporal dynamics of detrital pools; and (2) to determine to what extent present stand structure, topography, and soils constrain these dynamics. We collected data on downed dead wood, litter, duff (partially decomposed litter on the forest floor), stand structure, topographic position, and soils for 31 sites along a 160-year chronosequence. We developed a compartment model and parameterized it to describe the temporal trends in the detrital pools. We then developed four sets of statistical models, quantifying the hypothesized relationship between pool size and (1) stand structure, (2) topography, (3) soils variables, and (4) time since fire. We contrasted how much support each hypothesis had in the data using Akaike's Information Criterion (AIC). Time since fire explained 39-80% of the variability in dead wood of different size classes. Pool size increased to a peak as material killed by the fire fell, then decomposed rapidly to a minimum (61-85 years after fire for the different pools). It then increased, presumably as new detritus was produced by the regenerating stand. Litter was most strongly related to canopy cover (r2 = 77%), suggesting that litter fall, rather than decomposition, controls its dynamics. The temporal dynamics of duff were the hardest to predict. Detrital pool sizes were more strongly related to time since fire than to environmental variables. Woody debris peak-to-minimum time was 46-67 years, overlapping the range of historical fire return intervals (1 to > 100 years). Fires may therefore have burned under a

  17. Variations in soil chemical properties, microbial biomass, and faunal populations as related to plant functional traits, patch types, and successional stages at Sokolov post-mining site - A case study

    Czech Academy of Sciences Publication Activity Database

    Moradi, J.; Mudrák, Ondřej; Kukla, J.; Vicentini, F.; Šimáčková, H.; Frouz, J.

    2017-01-01

    Roč. 83, NOV-DEC (2017), s. 58-64 ISSN 1164-5563 Institutional support: RVO:67985939 Keywords : chronosequence * plant functional trait * faunal surface activity Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 2.445, year: 2016

  18. Changes in some physical properties of soils in the chronosequence of self-overgrown dumps of the Sokolov quarry-dump complex, Czechia

    Czech Academy of Sciences Publication Activity Database

    Kuráž, V.; Frouz, Jan; Kuráž, M.; Mako, A.; Šustr, Vladimír; Cejpek, J.; Romanov, O.V.; Abakumov, E.V.

    2012-01-01

    Roč. 45, č. 3 (2012), s. 266-272 ISSN 1064-2293 R&D Projects: GA MŠk 2B08023 Grant - others:Russian Foundation for Basic Research(RU) 08-04-01128 Institutional support: RVO:60077344 Keywords : physical properties of soil s * chronosequence of self-overgrown dumps * Sokolov quarry-dump complex Subject RIV: EH - Ecology, Behaviour Impact factor: 0.216, year: 2012

  19. Soils on raised marine terraces in the Metaponto area, S Italy: not a simple chronosequence

    Science.gov (United States)

    Sauer, Daniela; Al-Sharif, Riyad; Wagner, Stephen; Scarciglia, Fabio; Deffontaines, Benoît; Benvenuti, Marco; Carnicelli, Stefano; Brückner, Helmut

    2015-04-01

    A sequence of Middle and Late Pleistocene raised marine terraces stretches along the Gulf of Taranto, S Italy, for more than 65 km from Rocca Imperiale, Calabria, in the SW to Taranto, Apulia, in the NE, in an approximately 25 km wide belt. The terraces formed as a result of the interplay between sea-level fluctuations and regional tectonic uplift over a time-span of ca. 780 ka. They were selected for establishing a soil chronosequence, in order to analyse rates of soil-forming processes in the central Mediterranean region. Indeed, several general trends of soil formation with terrace age were identified. For example, soil thickness and Fed/Fet ratios increase, while the weathering ratio (Ca+Mg+K+Na)/Al decreases with assumed terrace age. These changes could be best described by power functions (R2 = 0.88 for soil thickness, R2 = 0.87 for Fed/Fet, and R2 = 0.96 for (Ca+Mg+K+Na)/Al). However, closer examination revealed that the soils did not simply form in the marine gravel bodies but in various kinds of sediments. The development of the landscape along the Gulf of Taranto turned out to be much more complex than previously expected. Sediment-soil successions exposed in several gravel quarries reveal that each terrace, after its original formation, was exposed to changing conditions in terms of climate, vegetation, level of erosion base (related to sea-level oscillations and/or tectonics), and other environmental factors during the Pleistocene and Holocene periods. As a result, it was subject to (i) further geomorphological and sedimentological evolution, including incision, denudation, deposition of alluvial sediments, and accumulation of colluvial deposits, in parts due to natural processes and in parts due to human activity; (ii) various directions and rates of soil development, corresponding to changing environmental conditions during glacial and interglacial periods. In some cases, there is evidence for a period of soil formation in the marine deposits prior to

  20. How does pedogenesis drive plant diversity?

    Science.gov (United States)

    Laliberté, Etienne; Grace, James B.; Huston, Michael A.; Lambers, Hans; Teste, François P.; Turner, Benjamin L.; Wardle, David A.

    2013-01-01

    Some of the most species-rich plant communities occur on ancient, strongly weathered soils, whereas those on recently developed soils tend to be less diverse. Mechanisms underlying this well-known pattern, however, remain unresolved. Here, we present a conceptual model describing alternative mechanisms by which pedogenesis (the process of soil formation) might drive plant diversity. We suggest that long-term soil chronosequences offer great, yet largely untapped, potential as 'natural experiments' to determine edaphic controls over plant diversity. Finally, we discuss how our conceptual model can be evaluated quantitatively using structural equation modeling to advance multivariate theories about the determinants of local plant diversity. This should help us to understand broader-scale diversity patterns, such as the latitudinal gradient of plant diversity.

  1. Ecosystem development after mangrove creation: plant-soil change across a twenty-year chronosequence in Tampa Bay, FL

    Science.gov (United States)

    On a global scale, the loss of mangroves has been high (~1-2% loss per year in recent decades). Recognizing the important ecosystem services supported by mangroves, restoration and creation efforts are increasingly proposed as mechanisms to replace those services lost after mangr...

  2. Soil recovery across a chronosequence of restored wetlands in the Florida Everglades

    OpenAIRE

    Qibing Wang; Yuncong Li; Min Zhang

    2015-01-01

    The restoration project in the Hole-in-the-Donut of Everglades National Park in Florida, USA is to reestablish native wetlands by complete removal of the invasive plants and the associated soil. However, there is little information available about changes in properties of the newly formed Marl soils in restored wetlands. In this study, we measured soil physicochemical properties, soil enzymatic activities, and stable isotopes of carbon (?13C) in plants and soil organic carbon (SOC) in an undi...

  3. Effects of permafrost thaw on CO2 and CH4 exchange in a western Alaska peatland chronosequence

    Science.gov (United States)

    Carmel E. Johnston,; Stephanie A. Ewing,; Harden, Jennifer W.; Ruth K. Varner,; Wickland, Kimberly P.; Koch, Joshua C.; Fuller, Christopher C.; Manies, Kristen L.; M. Torre Jorgenson,

    2014-01-01

    Permafrost soils store over half of global soil carbon (C), and northern frozen peatlands store about 10% of global permafrost C. With thaw, inundation of high latitude lowland peatlands typically increases the surface-atmosphere flux of methane (CH4), a potent greenhouse gas. To examine the effects of lowland permafrost thaw over millennial timescales, we measured carbon dioxide (CO2) and CH4 exchange along sites that constitute a ~1000 yr thaw chronosequence of thermokarst collapse bogs and adjacent fen locations at Innoko Flats Wildlife Refuge in western Alaska. Peak CH4exchange in July (123 ± 71 mg CH4–C m−2 d−1) was observed in features that have been thawed for 30 to 70 (peatlands, particularly those developed on poorly drained mineral substrates, are a key locus of elevated CH4 emission to the atmosphere that must be considered for a complete understanding of high latitude CH4 dynamics.

  4. Soil recovery across a chronosequence of restored wetlands in the Florida Everglades

    Science.gov (United States)

    Wang, Qibing; Li, Yuncong; Zhang, Min

    2015-12-01

    The restoration project in the Hole-in-the-Donut of Everglades National Park in Florida, USA is to reestablish native wetlands by complete removal of the invasive plants and the associated soil. However, there is little information available about changes in properties of the newly formed Marl soils in restored wetlands. In this study, we measured soil physicochemical properties, soil enzymatic activities, and stable isotopes of carbon (δ13C) in plants and soil organic carbon (SOC) in an undisturbed natural wetland (UNW) and three wetlands restored respectively in 1989, 1996 and 1999 (WR89, WR96 and WR99). The older restored wetlands (WR89 and WR96) are characterized by greater SOC and mineral nitrogen. The values of soil dehydrogenase and phosphatase activities in the four wetlands follow the order: UNW > WR89 > WR96 > WR99, and are consistent with changes in vegetation coverage. The principal component analysis shows that dehydrogenase and phosphatase activities are the vital variables contributing to the soil of UNW. The similar δ13C values of SOC and plants in the restored wetlands suggest the formation of SOC during restoration is mainly derived from the associated plants. These results indicate that the newly restored soils develop toward the soil in the UNW with time since restoration.

  5. Changes in coexistence mechanisms along a long-term soil chronosequence revealed by functional trait diversity

    Czech Academy of Sciences Publication Activity Database

    Mason, N. W. H.; Richardson, S. J.; Peltzer, D. A.; de Bello, Francesco; Wardle, D. A.; Allen, R. B.

    2012-01-01

    Roč. 100, č. 3 (2012), 678-689 ISSN 0022-0477 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : plant community diversity * environmental filtering * forest ecosystem Subject RIV: EH - Ecology, Behaviour Impact factor: 5.431, year: 2012

  6. Determining aboveground biomass of the forest successional chronosequence in a test-site of Brazilian Amazon through X- and L-band data analysis

    Science.gov (United States)

    Santos, João. R.; Silva, Camila V. d. J.; Galvão, Lênio S.; Treuhaft, Robert; Mura, José C.; Madsen, Soren; Gonçalves, Fábio G.; Keller, Michael M.

    2014-08-01

    Secondary succession is an important process in the Amazonian region with implications for the global carbon cycle and for the sustainable regional agricultural and pasture activities. In order to better discriminate the secondary succession and to characterize and estimate the aboveground biomass (AGB), backscatter and interferometric SAR data generally have been analyzed through empirical-based statistical modeling. The objective of this study is to verify the capability of the full polarimetric PALSAR/ALOS (L-band) attributes, when combined with the interferometric (InSAR) coherence from the TanDEM-X (X-band), to improve the AGB estimates of the succession chronosequence located in the Brazilian Tapajós region. In order to perform this study, we carried out multivariate regression using radar attributes and biophysical parameters acquired during a field inventory. A previous floristic-structural analysis was performed to establish the chronosequence in three stages: initial vegetation regrowth, intermediate, and advanced regrowth. The relationship between PALSAR data and AGB was significant (p<0.001) and results suggested that the "volumetric scattering" (Pv) and "anisotropy" (A) attributes were important to explain the biomass content of the successional chronosequence (R2adjusted = 0.67; RMSE = 32.29 Mg.ha-1). By adding the TanDEM-derived interferometric coherence (Υi) into the regression modeling, better results were obtained (R2adjusted = 0.75; RMSE = 28.78Mg.ha-1). When we used both the L- and X-band attributes, the stock density prediction improved to 10.8 % for the secondary succession stands.

  7. The role of reaction affinity and secondary minerals in regulating chemical weathering rates at the Santa Cruz Soil Chronosequence, California

    Science.gov (United States)

    Maher, K.; Steefel, Carl; White, A.F.; Stonestrom, David A.

    2009-01-01

    In order to explore the reasons for the apparent discrepancy between laboratory and field weathering rates and to determine the extent to which weathering rates are controlled by the approach to thermodynamic equilibrium, secondary mineral precipitation, and flow rates, a multicomponent reactive transport model (CrunchFlow) was used to interpret soil profile development and mineral precipitation and dissolution rates at the 226 ka Marine Terrace Chronosequence near Santa Cruz, CA. Aqueous compositions, fluid chemistry, transport, and mineral abundances are well characterized [White A. F., Schulz M. S., Vivit D. V., Blum A., Stonestrom D. A. and Anderson S. P. (2008) Chemical weathering of a Marine Terrace Chronosequence, Santa Cruz, California. I: interpreting the long-term controls on chemical weathering based on spatial and temporal element and mineral distributions. Geochim. Cosmochim. Acta 72 (1), 36-68] and were used to constrain the reaction rates for the weathering and precipitating minerals in the reactive transport modeling. When primary mineral weathering rates are calculated with either of two experimentally determined rate constants, the nonlinear, parallel rate law formulation of Hellmann and Tisserand [Hellmann R. and Tisserand D. (2006) Dissolution kinetics as a function of the Gibbs free energy of reaction: An experimental study based on albite feldspar. Geochim. Cosmochim. Acta 70 (2), 364-383] or the aluminum inhibition model proposed by Oelkers et al. [Oelkers E. H., Schott J. and Devidal J. L. (1994) The effect of aluminum, pH, and chemical affinity on the rates of aluminosilicate dissolution reactions. Geochim. Cosmochim. Acta 58 (9), 2011-2024], modeling results are consistent with field-scale observations when independently constrained clay precipitation rates are accounted for. Experimental and field rates, therefore, can be reconciled at the Santa Cruz site. Additionally, observed maximum clay abundances in the argillic horizons occur at

  8. Effect of permafrost thaw on CO2 and CH4 exchange in a western Alaska peatland chronosequence

    International Nuclear Information System (INIS)

    Johnston, Carmel E; Ewing, Stephanie A; Harden, Jennifer W; Fuller, Christopher C; Manies, Kristen; Varner, Ruth K; Wickland, Kimberly P; Koch, Joshua C; Jorgenson, M Torre

    2014-01-01

    Permafrost soils store over half of global soil carbon (C), and northern frozen peatlands store about 10% of global permafrost C. With thaw, inundation of high latitude lowland peatlands typically increases the surface-atmosphere flux of methane (CH 4 ), a potent greenhouse gas. To examine the effects of lowland permafrost thaw over millennial timescales, we measured carbon dioxide (CO 2 ) and CH 4 exchange along sites that constitute a ∼1000 yr thaw chronosequence of thermokarst collapse bogs and adjacent fen locations at Innoko Flats Wildlife Refuge in western Alaska. Peak CH 4 exchange in July (123 ± 71 mg CH 4 –C m −2 d −1 ) was observed in features that have been thawed for 30 to 70 (<100) yr, where soils were warmer than at more recently thawed sites (14 to 21 yr; emitting 1.37 ± 0.67 mg CH 4 –C m −2 d −1 in July) and had shallower water tables than at older sites (200 to 1400 yr; emitting 6.55 ± 2.23 mg CH 4 –C m −2 d −1 in July). Carbon lost via CH 4 efflux during the growing season at these intermediate age sites was 8% of uptake by net ecosystem exchange. Our results provide evidence that CH 4 emissions following lowland permafrost thaw are enhanced over decadal time scales, but limited over millennia. Over larger spatial scales, adjacent fen systems may contribute sustained CH 4 emission, CO 2 uptake, and DOC export. We argue that over timescales of decades to centuries, thaw features in high-latitude lowland peatlands, particularly those developed on poorly drained mineral substrates, are a key locus of elevated CH 4 emission to the atmosphere that must be considered for a complete understanding of high latitude CH 4 dynamics. (paper)

  9. Molecular Ecology of nifH Genes and Transcripts Along a Chronosequence in Revegetated Areas of the Tengger Desert.

    Science.gov (United States)

    Wang, Jin; Bao, Jing-Ting; Li, Xin-Rong; Liu, Yu-Bing

    2016-01-01

    The colonization and succession of diazotrophs are essential for the development of organic soil layers in desert. We examined the succession of diazotrophs in the well-established revegetated areas representing a chronosequence of 0 year (control), 22 years (restored artificially since 1981), 57 years (restored artificially since 1956), and more than 100 years (restored naturally) to determine the community assembly and active expression of diazotrophs. The pyrosequencing data revealed that Alphaproteobacteria-like diazotrophs predominated in the topsoil of our mobile dune site, while cyanobacterial diazotrophs predominated in the revegetated sites. The cyanobacterial diazotrophs were primarily composed of the heterocystous genera Anabaena, Calothrix, Cylindrospermum, Nodularia, Nostoc, Trichormus, and Mastigocladus. Almost all the nifH sequences belonged to the Cyanobacteria phylum (all the relative abundance values >99.1 %) at transcript level and all the active cyanobacterial diazotrophs distributed in the families Nostocaceae and Rivulariaceae. The most dominant active cyanobacterial genus was Cylindrospermum in all the samples. The rank abundance and community analyses demonstrated that most of the diazotrophic diversity originated from the "rare" species, and all the DNA-based diazotrophic libraries were richer and more diverse than their RNA-based counterparts in the revegetated sites. Significant differences in the diazotrophic community and their active population composition were observed among the four research sites. Samples from the 1981-revegetating site (predominated by cyanobacterial crusts) showed the highest nitrogenase activity, followed by samples from the naturally revegetating site (predominated by lichen crusts), the 1956-revegetating site (predominated by moss crusts), and the mobile dune site (without crusts). Collectively, our data highlight the importance of nitrogen fixation by the primary successional desert topsoil and suggest

  10. Elemental and mineralogical changes in soils due to bioturbation along an earthworm invasion chronosequence in Northern Minnesota

    Energy Technology Data Exchange (ETDEWEB)

    Resner, Kathryn [Dept. of Soil, Water, and Climate, University of Minnesota, 439 Borlaug Hall, 1991 Upper Buford Circle, St. Paul, MN, 55108-6028 (United States); Yoo, Kyungsoo, E-mail: kyoo@umn.edu [Dept. of Soil, Water, and Climate, University of Minnesota, 439 Borlaug Hall, 1991 Upper Buford Circle, St. Paul, MN, 55108-6028 (United States); Hale, Cindy [University of Minnesota Duluth, The Natural Resources Research Institute, 5013 Miller Trunk Hwy. Duluth, MN 55811 (United States); Aufdenkampe, Anthony [Assistant Research Scientist - Isotope and Organic Geochemistry, Stroud Water Research Center, 970 Spencer Road, Avondale, PA 19311 (United States); Blum, Alex [US Geological Survey, 3215 Marine St., Boulder, CO 80303 (United States); Sebestyen, Stephen [Research Hydrologist, USDA Forest Service, Northern Research Station, Grand Rapids, MN 55744-3399 (United States)

    2011-06-15

    Minnesota forested soils have evolved without the presence of earthworms since the last glacial retreat. When exotic earthworms arrive, enhanced soil bioturbation often results in dramatic morphological and chemical changes in soils with negative implications for the forests' sustainability. However, the impacts of earthworm invasion on geochemical processes in soils are not well understood. This study attempts to quantify the role of earthworm invasion in mineral chemical weathering and nutrient dynamics along an earthworm invasion chronosequence in a sugar maple forest in Northern Minnesota. Depth and rates of soil mixing can be tracked with atmospherically derived short lived radioisotopes {sup 210}Pb and {sup 137}Cs. Their radioactivities increase in the lower A horizon at the expense of the peak activities near the soil surface, which indicate that soil mixing rate and its depth reach have been enhanced by earthworms. Enhanced soil mixing by earthworms is consistent with the ways that the vertical profiles of elemental and mineralogical compositions were affected by earthworm invasion. Biologically cycled Ca and P have peak concentrations near the soil surface prior to earthworm invasion. However, these peak abundances significantly declined in the earthworm invaded soils presumably due to enhanced soil mixing. It is clear that enhanced soil mixing due to earthworms also profoundly altered the vertical distribution of most mineral species within A horizons. Though the mechanisms are not clear yet, earthworm invasion appears to have contributed to net losses of clay mineral species and opal from the A horizons. As much as earthworms vertically relocated minerals and elements, they also intensify the contacts between organic matter and cations as shown in the increased amount of Ca and Fe in organically complexed and in exchangeable pools. With future studies on soil mixing rates and elemental leaching, this study will quantitatively and mechanically

  11. The impact of wildfire on stream fishes in an Atlantic-Mediterranean climate: evidence from an 18-year chronosequence

    Directory of Open Access Journals (Sweden)

    Monaghan K.A.

    2016-01-01

    Full Text Available The predicted increase in wildfires associated with climate change poses a risk to freshwater biodiversity that may be exacerbated by river regulation. We studied the effects of wildfire and river management on the fish assemblages of Atlantic-Mediterranean streams in northern Portugal. Employing a chronosquence survey covering an 18-year gradient of impact-recovery from major fire events (ca. 100% catchment burnt, we assessed the ecological response with respect to time since wildfire, interpreting fish assemblages in the context of species traits and characteristics of the river habitat. Non-burnt sites (N = 18; surveyed 4 years previously were compared to burnt sites (N = 14, two of which were part of the non-burnt set, thus providing a Before-After Impact comparison (BAI; N = 2. Across burnt sites richness and abundance were not related to time since wildfire. BAI revealed a contrast in the response of different species that corresponded to descriptive evidence from the chronosequence of burnt sites. As resource specialists, Salmo trutta were negatively impacted by wildfire; Iberian endemic cyprinids, characterized by generalist traits, demonstrated resistance. Habitat structure was a key determinant of wildfire-impact, increasing with channel slope and the degree of channelization. The low abundance of migratory taxa (S. trutta and Anguilla anguilla at burnt sites suggested the importance of fish mobility to post-fire recovery. These data demonstrate that trait profiles and habitat descriptions provide pragmatic information for the management of rivers in fire-susceptible regions and suggest that the rehabilitation of these upland stream habitats might enhance ecological resistance and resilience to catchment wildfire.

  12. Microbial and geochemical assessment of bauxitic un-mined and post-mined chronosequence soils from Mocho Mountains, Jamaica.

    Science.gov (United States)

    Lewis, Dawn E; Chauhan, Ashvini; White, John R; Overholt, Will; Green, Stefan J; Jasrotia, Puja; Wafula, Denis; Jagoe, Charles

    2012-10-01

    Microorganisms are very sensitive to environmental change and can be used to gauge anthropogenic impacts and even predict restoration success of degraded environments. Here, we report assessment of bauxite mining activities on soil biogeochemistry and microbial community structure using un-mined and three post-mined sites in Jamaica. The post-mined soils represent a chronosequence, undergoing restoration since 1987, 1997, and 2007. Soils were collected during dry and wet seasons and analyzed for pH, organic matter (OM), total carbon (TC), nitrogen (TN), and phosphorus. The microbial community structure was assessed through quantitative PCR and massively parallel bacterial ribosomal RNA (rRNA) gene sequencing. Edaphic factors and microbial community composition were analyzed using multivariate statistical approaches and revealed a significant, negative impact of mining on soil that persisted even after greater than 20 years of restoration. Seasonal fluctuations contributed to variation in measured soil properties and community composition, but they were minor in comparison to long-term effects of mining. In both seasons, post-mined soils were higher in pH but OM, TC, and TN decreased. Bacterial rRNA gene analyses demonstrated a general decrease in diversity in post-mined soils and up to a 3-log decrease in rRNA gene abundance. Community composition analyses demonstrated that bacteria from the Proteobacteria (α, β, γ, δ), Acidobacteria, and Firmicutes were abundant in all soils. The abundance of Firmicutes was elevated in newer post-mined soils relative to the un-mined soil, and this contrasted a decrease, relative to un-mined soils, in proteobacterial and acidobacterial rRNA gene abundances. Our study indicates long-lasting impacts of mining activities to soil biogeochemical and microbial properties with impending loss in soil productivity.

  13. Changes in soil moisture drive soil methane uptake along a fire regeneration chronosequence in a eucalypt forest landscape.

    Science.gov (United States)

    Fest, Benedikt; Wardlaw, Tim; Livesley, Stephen J; Duff, Thomas J; Arndt, Stefan K

    2015-11-01

    Disturbance associated with severe wildfires (WF) and WF simulating harvest operations can potentially alter soil methane (CH4 ) oxidation in well-aerated forest soils due to the effect on soil properties linked to diffusivity, methanotrophic activity or changes in methanotrophic bacterial community structure. However, changes in soil CH4 flux related to such disturbances are still rarely studied even though WF frequency is predicted to increase as a consequence of global climate change. We measured in-situ soil-atmosphere CH4 exchange along a wet sclerophyll eucalypt forest regeneration chronosequence in Tasmania, Australia, where the time since the last severe fire or harvesting disturbance ranged from 9 to >200 years. On all sampling occasions, mean CH4 uptake increased from most recently disturbed sites (9 year) to sites at stand 'maturity' (44 and 76 years). In stands >76 years since disturbance, we observed a decrease in soil CH4 uptake. A similar age dependency of potential CH4 oxidation for three soil layers (0.0-0.05, 0.05-0.10, 0.10-0.15 m) could be observed on incubated soils under controlled laboratory conditions. The differences in soil CH4 uptake between forest stands of different age were predominantly driven by differences in soil moisture status, which affected the diffusion of atmospheric CH4 into the soil. The observed soil moisture pattern was likely driven by changes in interception or evapotranspiration with forest age, which have been well described for similar eucalypt forest systems in south-eastern Australia. Our results imply that there is a large amount of variability in CH4 uptake at a landscape scale that can be attributed to stand age and soil moisture differences. An increase in severe WF frequency in response to climate change could potentially increase overall forest soil CH4 sinks. © 2015 John Wiley & Sons Ltd.

  14. Assessment of carbon sequestration potential of revegetated coal mine overburden dumps: A chronosequence study from dry tropical climate.

    Science.gov (United States)

    Ahirwal, Jitendra; Maiti, Subodh Kumar

    2017-10-01

    Development of secondary forest as post-mining land use in the surface coal mining degraded sites is of high research interest due to its potential to sequester atmospheric carbon (C). The objectives of this study were to assess the improvement in mine soil quality and C sequestration potential of the post-mining reclaimed land with time. Hence, this study was conducted in reclaimed chronosequence sites (young, intermediate and old) of a large open cast coal project (Central Coal Fields Limited, Jharkhand, India) and results were compared to a reference forest site (Sal forest, Shorea robusta). Mine soil quality was assessed in terms of accretion of soil organic carbon (SOC), available nitrogen (N) and soil CO 2 flux along with the age of revegetation. After 14 years of revegetation, SOC and N concentrations increased three and five-fold, respectively and found equivalent to the reference site. Accretion of SOC stock was estimated to be 1.9 Mg C ha -1 year -1 . Total ecosystem C sequestered after 2-14 years of revegetation increased from 8 Mg C ha -1 to 90 Mg C ha -1 (30-333 Mg CO 2 ha -1 ) with an average rate of 6.4 Mg C ha -1 year -1 . Above ground biomass contributes maximum C sequestrate (50%) in revegetated site. CO 2 flux increased with age of revegetation and found 11, 33 and 42 Mg CO 2 ha -1 year -1 in younger, intermediate and older dumps, respectively. Soil respiration in revegetated site is more influenced by the temperature than soil moisture. Results of the study also showed that trees like, Dalbergia sissoo and Heterophragma adenophyllum should be preferred for revegetation of mine degraded sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Elemental and mineralogical changes in soils due to bioturbation along an earthworm invasion chronosequence in Northern Minnesota

    International Nuclear Information System (INIS)

    Resner, Kathryn; Yoo, Kyungsoo; Hale, Cindy; Aufdenkampe, Anthony; Blum, Alex; Sebestyen, Stephen

    2011-01-01

    Minnesota forested soils have evolved without the presence of earthworms since the last glacial retreat. When exotic earthworms arrive, enhanced soil bioturbation often results in dramatic morphological and chemical changes in soils with negative implications for the forests' sustainability. However, the impacts of earthworm invasion on geochemical processes in soils are not well understood. This study attempts to quantify the role of earthworm invasion in mineral chemical weathering and nutrient dynamics along an earthworm invasion chronosequence in a sugar maple forest in Northern Minnesota. Depth and rates of soil mixing can be tracked with atmospherically derived short lived radioisotopes 210 Pb and 137 Cs. Their radioactivities increase in the lower A horizon at the expense of the peak activities near the soil surface, which indicate that soil mixing rate and its depth reach have been enhanced by earthworms. Enhanced soil mixing by earthworms is consistent with the ways that the vertical profiles of elemental and mineralogical compositions were affected by earthworm invasion. Biologically cycled Ca and P have peak concentrations near the soil surface prior to earthworm invasion. However, these peak abundances significantly declined in the earthworm invaded soils presumably due to enhanced soil mixing. It is clear that enhanced soil mixing due to earthworms also profoundly altered the vertical distribution of most mineral species within A horizons. Though the mechanisms are not clear yet, earthworm invasion appears to have contributed to net losses of clay mineral species and opal from the A horizons. As much as earthworms vertically relocated minerals and elements, they also intensify the contacts between organic matter and cations as shown in the increased amount of Ca and Fe in organically complexed and in exchangeable pools. With future studies on soil mixing rates and elemental leaching, this study will quantitatively and mechanically address the role of

  16. Mean latitudinal range sizes of bird assemblages in six Neotropical forest chronosequences

    DEFF Research Database (Denmark)

    Dunn, Robert R.; Romdal, Tom Skovlund

    2005-01-01

    Aim The geographical range size frequency distributions of animal and plant assemblages are among the most important factors affecting large-scale patterns of diversity. Nonetheless, the relationship between habitat type and the range size distributions of species forming assemblages remains poorly...... towards more small ranged species occurs. Even relatively old secondary forests have bird species with larger average ranges than mature forests. As a consequence, conservation of secondary forests alone will miss many of the species most at risk of extinction and most unlikely to be conserved in other...

  17. Soil nitrogen dynamics within profiles of a managed moist temperate forest chronosequence consistent with long-term harvesting-induced losses

    Science.gov (United States)

    Kellman, Lisa; Kumar, Sanjeev; Diochon, Amanda

    2014-07-01

    This study investigates whether clear-cut forest harvesting leads to alterations in the decadal-scale biogeochemical nitrogen (N) cycles of moist temperate forest ecosystems. Using a harvested temperate red spruce (Picea rubens Sarg.) forest chronosequence in Nova Scotia, Canada, representing 80 year old postharvest conditions, alongside a reference old-growth (125+ year old) site with no documented history of disturbance, we examine harvesting-related changes in soil N pools and fluxes. Specifically, we quantify soil N storage with depth and age across the forest chronosequence, examine changes in physical fractions and δ15N of soil N through depth and time, and quantify gross soil N transformation rates through depth and time using a 15N isotope dilution technique. Our findings point to a large loss of total N in the soil pool, particularly within the deep soil (>20 cm) and organomineral fractions. A pulse of available mineralized N (as ammonium) was observed following harvesting (mean residence time (MRT) > 6 days), but its MRT dropped to estimates that suggest soil N may not reaccrue for almost a century following this disturbance.

  18. The effect of temperature change on the microbial diversity and community structure along the chronosequence of the sub-arctic glacier forefield of Styggedalsbreen (Norway).

    Science.gov (United States)

    Mateos-Rivera, Alejandro; Yde, Jacob C; Wilson, Bryan; Finster, Kai W; Reigstad, Laila J; Øvreås, Lise

    2016-04-01

    Microbial communities in the glacier forefield of Styggedalsbreen, Norway, were investigated along a chronosequence from newly exposed soil to vegetated soils using next-generation sequencing of the 16S rRNA gene. In order to monitor the short-term effect of temperature on community successions along the soil gradient, the soil samples were incubated at three different temperatures (5°C, 10°C and 22°C). The microbial community composition along the chronosequence differed according to distance from the glacial terminus and incubation temperature. Samples close to the glacier terminus were dominated by Proteobacteria at 5°C and 10°C, while at 22°C members of Chloroflexi, Acidobacteria and Verrucomicrobia in addition to Proteobacteria accounted for most of the diversity, indicating that sites close to the glacier terminus are more closely related to former subglacial environments. Within the Archaea domain, members of the phylum Euryarchaeota dominated in samples closer to the glacier terminus with a shift to members of the phyla Thaumarchaeota-Crenarchaeota with increased soil age. Our data indicate that composition and diversity of the microbial communities along the glacier forefield depend not only on exposure time but are also to a large degree influenced by soil surface temperature and soil maturation. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. How much will afforestation of former cropland influence soil C stocks? A synthesis of paired sampling, chronosequence sampling and repeated sampling studies

    Science.gov (United States)

    Vesterdal, Lars; Hansen, K.; Stupak, I.; Don, Axel; Poeplau, C.; Leifeld, Jens; van Wesemael, Bas

    2010-05-01

    The need for documentation of land-use change effects on soil C is high on the agenda in most signatory countries to the Kyoto Protocol. Large land areas in Europe have experienced land-use change from cropland to forest since 1990 by direct afforestation as well as abandonment and regrowth of marginally productive cropland. Soil C dynamics following land-use change remain highly uncertain due to a limited number of available studies and due to influence of interacting factors such as land use history, soil type, and climate. Common approaches for estimation of potential soil C changes following land-use change are i) paired sampling of plots with a long legacy of different land uses, ii) chronosequence studies of land-use change, and lastly iii) repeated sampling of plots subject to changed land use. This paper will synthesize the quantitative effects of cropland afforestation on soil C sequestration based on all three approaches and will report on related work within Cost 639. Paired plots of forest and cropland were used to study the general differences between soil C stocks in the two land uses. At 27 sites in Denmark distributed among different regions and soil types forest floor and mineral soil were sampled in and around soil pits. Soil C stocks were higher in forest than cropland (mean difference 22 Mg C ha-1 to 1 m depth). This difference was caused solely by the presence of a forest floor in forests; mineral soil C stocks were similar (108 vs. 109 Mg C ha-1) in the two land uses regardless of soil type and the soil layers considered. The chronosequence approach was employed in the AFFOREST project for evaluation of C sequestration in biomass and soils following afforestation of cropland. Two oak (Quercus robur) and four Norway spruce (Picea abies) afforestation chronosequences (age range 1 to 90 years) were studied in Denmark, Sweden and the Netherlands. Forest floor and mineral soil (0-25 cm) C contents were as a minimum unchanged and in most cases there

  20. Microbial food web dynamics along a soil chronosequence of a glacier forefield

    Directory of Open Access Journals (Sweden)

    J. Esperschütz

    2011-11-01

    Full Text Available Microbial food webs are critical for efficient nutrient turnover providing the basis for functional and stable ecosystems. However, the successional development of such microbial food webs and their role in "young" ecosystems is unclear. Due to a continuous glacier retreat since the middle of the 19th century, glacier forefields have expanded offering an excellent opportunity to study food web dynamics in soils at different developmental stages. In the present study, litter degradation and the corresponding C fluxes into microbial communities were investigated along the forefield of the Damma glacier (Switzerland. 13C-enriched litter of the pioneering plant Leucanthemopsis alpina (L. Heywood was incorporated into the soil at sites that have been free from ice for approximately 10, 60, 100 and more than 700 years. The structure and function of microbial communities were identified by 13C analysis of phospholipid fatty acids (PLFA and phospholipid ether lipids (PLEL. Results showed increasing microbial diversity and biomass, and enhanced proliferation of bacterial groups as ecosystem development progressed. Initially, litter decomposition proceeded faster at the more developed sites, but at the end of the experiment loss of litter mass was similar at all sites, once the more easily-degradable litter fraction was processed. As a result incorporation of 13C into microbial biomass was more evident during the first weeks of litter decomposition. 13C enrichments of both PLEL and PLFA biomarkers following litter incorporation were observed at all sites, suggesting similar microbial foodwebs at all stages of soil development. Nonetheless, the contribution of bacteria, especially actinomycetes to litter turnover became more pronounced as soil age increased in detriment of archaea, fungi and protozoa, more prominent in recently deglaciated terrain.

  1. Carbon Stocks across a Fifty Year Chronosequence of Rubber Plantations in Tropical China

    Directory of Open Access Journals (Sweden)

    Chenggang Liu

    2017-06-01

    Full Text Available Transition from forest to rubber (Hevea brasiliensis Muell. Arg. plantation has occurred in tropical China for decades. Rubber has been planted on 1 million ha to provide raw materials to the rubber industry. The role of various-aged rubber plantations in carbon (C sequestration remains unclear. The biomass C accumulation including latex C and C distribution in soil of five different-aged stands (7, 13, 19, 25 and 47 years old were examined. The total biomass C stock (TBC and total net primary productivity (NPPtotal, whether with or without latex C, had a close quadratic relationship with stand age. Regardless of stand age, around 68% of the C was stored in aboveground biomass, and NPPlatex contributed to approximately 18% of C sequestration. Soil organic carbon stock in the 100-cm depth remained relatively stable, but it lost about 16.8 Mg ha−1 with stand age. The total ecosystem C stock (TEC across stands averaged 159.6, 174.4, 229.6, 238.1 and 291.9 Mg ha−1, respectively, of which more than 45% was stored in the soil. However, biomass would become the major C sink rather than soil over a maximal rubber life expectancy. Regression analysis showed that TEC for rubber plantation at 22 years is comparable to a baseline of 230.4 Mg ha−1 for tropical forest in China, and would reach the maximum value at around 54 years. Therefore, rubber plantation can be considered as alternative land use without affecting net forest ecosystem C storage. In addition to the potential C gains, a full set of ecosystem and economic properties have to be quantified in order to assess the trade-offs associated with forest-to-rubber transition.

  2. The role of reaction affinity and secondary minerals in regulating chemical weathering rates at the Santa Cruz Soil Chronosequence, California

    Energy Technology Data Exchange (ETDEWEB)

    Maher, K.; Steefel, C. I.; White, A.F.; Stonestrom, D.A.

    2009-02-25

    In order to explore the reasons for the apparent discrepancy between laboratory and field weathering rates and to determine the extent to which weathering rates are controlled by the approach to thermodynamic equilibrium, secondary mineral precipitation and flow rates, a multicomponent reactive transport model (CrunchFlow) was used to interpret soil profile development and mineral precipitation and dissolution rates at the 226 ka marine terrace chronosequence near Santa Cruz, CA. Aqueous compositions, fluid chemistry, transport, and mineral abundances are well characterized (White et al., 2008, GCA) and were used to constrain the reaction rates for the weathering and precipitating minerals in the reactive transport modeling. When primary mineral weathering rates are calculated with either of two experimentally determined rate constants, the nonlinear, parallel rate law formulation of Hellmann and Tisser and [2006] or the aluminum inhibition model proposed by Oelkers et al. [1994], modeling results are consistent with field-scale observations when independently constrained clay precipitation rates are accounted for. Experimental and field rates, therefore, can be reconciled at the Santa Cruz site. Observed maximum clay abundances in the argillic horizons occur at the depth and time where the reaction fronts of the primary minerals overlap. The modeling indicates that the argillic horizon at Santa Cruz can be explained almost entirely by weathering of primary minerals and in situ clay precipitation accompanied by undersaturation of kaolinite at the top of the profile. The rate constant for kaolinite precipitation was also determined based on model simulations of mineral abundances and dissolved Al, SiO{sub 2}(aq) and pH in pore waters. Changes in the rate of kaolinite precipitation or the flow rate do not affect the gradient of the primary mineral weathering profiles, but instead control the rate of propagation of the primary mineral weathering fronts and thus total

  3. Development of soil quality along a chronosequence under natural succession in the Dragonja catchment, SW Slovenia

    Science.gov (United States)

    van Hall, Rutger; Cammeraat, Erik

    2015-04-01

    Agricultural fields have been increasingly abandoned in several regions in Southern Europe. In many cases this leads to natural vegetation succession which may have a direct impact on soil quality,biodiversity and hydrological connectivity. This research aims at getting insight on the effects of natural vegetation succession on the development of soil quality in the Sub-Mediterranean Dragonja catchment in SW Slovenia. This site was chosen due to its uniform geology, geomorphology and soil types. Four different stages of vegetation succession (i.e. field, abandoned field, young forest, semi-mature forest) were selected and sampled on both north-, and south-facing slopes, resulting in 8 treatments for which 6 representative sites were sampled. Samples were analysed on OC and TN content, EC, pH, bulk density, aggregate stability and grain size distribution. To get insight on the changes in biodiversity vegetation records were made distinguishing five different plant functional groups (i.e. juveniles, grasses, herbs, shrubs and trees). Age group (i.e. stage of vegetation succession) significantly influenced the OC and TN content, aggregate stability, bulk density and pH. Directly after abandonment, between age group 0 and 1, OC and TN content, aggregate stability and pH increased significantly and bulk density decreased significantly. OC content was most affected by age group and furthermore significantly correlated to TN content, aggregate stability, bulk density and pH. Regarding biodiversity, there was a significant increase in cover by trees between age group 1 and 2 and a significant decrease between age group 2 and 3. Cover by herbs decreased significantly between age group 1 and 2. The number of different trees and shrubs increased significantly between age group 0 and 1, and the number of different juveniles increased significantly between age group 2 and 3. Another factor significantly influencing the soil's quality is aspect. Although not found for each age

  4. Expected and unexpected features in soil chronosequences in SE-Norway: Podzolization in Albeluvisols and Lessivage in Podzols

    Science.gov (United States)

    Sauer, D.; Schülli-Maurer, I.; Sperstad, R.; Sørensen, R.; Stahr, K.

    2009-04-01

    Introduction The Oslofjord region in SE-Norway has been subject to steady glacio-isostatic uplift during the whole Holocene. The final retreat of the ice at the termination of the last glacial took place in this area between 13,900 (retreat from Hvaler ice-marginal ridge) and 11,500 years BP (retreat from Ski ice-marginal ridge). Since then, the area has been characterized by continuous glacio-isostatic uplift. The upper limit of the former sea level varies between 155 m a.s.l. at Larvik, Vestfold, and 190 m a.s.l. at Halden, Østfold. This region provides particularly suitable conditions for studying soil development with time, because land surface age continuously increases from the coast inland. Several sea level curves, based on radiocarbon datings, enable estimation of land surface age for all locations. Study areas Soil chronosequences have been studied in the counties Vestfold and Østfold situated at the western and eastern side of the Oslofjord, between 59° and 59°40' North and 10° to 11°30' East. The climate in the study area is moist and comparatively mild, with mean annual temperatures ranging between 4.8 and 6.4 °C and a mean annual precipitation of 909 - 1150 mm in Vestfold and 770 - 880 mm in Østfold. The vegetation consists predominantly of mixed forest. Soil formation in loamy marine sediments leads to Albeluvisols; soil development in beach sand to Podzols. The soil chronosequences Twelve pedons were studied in loamy marine sediments under forest, six each in Vestfold and Østfold respectively. Land surface ages at the sites range from 1650 to 11 050 years. In addition, three samples of fresh sediments were taken from the shore line. The fresh sediments were characterized by varying amounts of carbonates in the form of shell fragments. Rapid drop in pH during drying of the samples indicated the presence of sulfides. Clay illuviation in the loamy sediments started in less than 1,650 years. E horizons became lighter with age, but their lower

  5. Carbon Dynamics of Reclaimed Coal Mine Soil under Agricultural Use: A Chronosequence Study in the Dongtan Mining Area, Shandong Province, China

    Directory of Open Access Journals (Sweden)

    Jun-Feng Qu

    2017-04-01

    Full Text Available Soil organic carbon (SOC plays an essential role in the early stages of pedogenisis and ecological restoration in reclaimed mine soils. Dynamic changes in the SOC content are essential for assessing the quality of reclaimed mine soils and the effect of ecological restoration. To objectively assess the carbon dynamics of reclaimed soils, we selected the surface (0–20 cm soil of farmland under agricultural use (soybean–wheat rotation from a reclamation chronosequence (R4: 4 years of reclamation, R7: 7 years of reclamation, R10: 10 years of reclamation and R13: 13 years of reclamation in the Dongtan Mining Area, Shandong Province, China. The adjacent normal, unaffected farmland was used as a control (CK. The results showed that the SOC content gradually increased with the reclamation age until it reached 7.98 g·kg−1 for R13, which accounted for 76% of that of the CK. However, the total carbon contents of the reclaimed soils did not significantly differ from and even appeared higher than that of the CK. This is mainly because the inorganic carbon contents of the reclaimed soils ranged from 2.98 to 12.61 g·kg−1, all of which were significantly higher than the 0.87 g·kg−1 obtained for the CK. The microbial biomass carbon (MBC content and the microbial quotient significantly increased with the reclamation age of the soil, and both parameters were markedly higher for R13 than for the CK. The dissolved organic carbon (DOC content and its ratio to the SOC were significantly higher for R4–R13 than for the CK and DOC/SOC gradually decreased with the reclamation age. Both the reclamation age and the temperature had positive effects on the soil basal respiration (SBR. The SBR rate constantly increased with the reclamation age and was markedly higher at 25 °C than at 15 °C. The temperature sensitivity (Q10 of the SBR showed a clearly decreasing trend for the reclamation chronosequence, but its value remained higher for R13 than for the CK (2

  6. CO{sub 2} and N{sub 2}O emissions in a soil chronosequence at a glacier retreat zone in Maritime Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Thomazini, A., E-mail: andre.thz@gmail.com [Department of Plant Production, Federal University of Espírito Santo, 29500-000 Alegre, Espírito Santo (Brazil); Mendonça, E.S., E-mail: eduardo.mendonca@ufes.br [Department of Plant Production, Federal University of Espírito Santo, 29500-000 Alegre, Espírito Santo (Brazil); Teixeira, D.B., E-mail: daniel.dbt@hotmail.com [FCAV/UNESP, Via de Acesso, Prof. Paulo Donato Castellane s/n, 14884-900 Jaboticabal, SP (Brazil); Almeida, I.C.C., E-mail: ivancarreiro@yahoo.com.br [Instituto Federal do Norte de Minas Gerais, Fazenda São Geraldo, s/n km. 06, 39480-000 Januária, Minas Gerais (Brazil); La Scala, N., E-mail: lascala@fcav.unesp.br [FCAV/UNESP, Via de Acesso, Prof. Paulo Donato Castellane s/n, 14884-900 Jaboticabal, SP (Brazil); Canellas, L.P., E-mail: lucianocanellas@gmail.com [UENF — Universidade Estadual do Norte Fluminense Darcy Ribeiro, Núcleo de Desenvolvimento de Insumos Biológicos para a Agricultura (NUDIBA), Av. Alberto Lamego, 2000, Campos dos Goytacazes 28013-602, Rio de Janeiro (Brazil); Spokas, K.A., E-mail: kurt.Spokas@ars.usda.gov [USDA-ARS, Soil and Water Management Unit, University of Minnesota — St. Paul, MN 55108 (United States); Milori, D.M.B.P., E-mail: debora.milori@embrapa.br [Embrapa Instrumentation Brazilian Agricultural Research Corporation, São Carlos, SP (Brazil); Turbay, C.V.G., E-mail: cturbay@gmail.com [Department of Geology, Federal University of Espírito Santo, 29500-000 Alegre, Espírito Santo (Brazil); and others

    2015-07-15

    Studies of C cycle alterations are extremely important to identify changes due to climate change, especially in the polar ecosystem. The objectives of this study were to (i) examine patterns of soil CO{sub 2}-C and N{sub 2}O-N emissions, and (ii) evaluate the quantity and quality of soil organic matter across a glacier retreat chronosequence in the Maritime Antarctica. Field measurements were carried out during January and February 2010 (summer season) along a retreating zone of the White Eagle Glacier, at King George Island, Maritime Antarctica. Soil samples (0–10 cm) were collected along a 500-m transect at regular intervals to determine changes in soil organic matter. Field CO{sub 2}-C emission measurements and soil temperature were carried out at regular intervals. In addition, greenhouse gas production potentials were assessed through 100 days laboratory incubations. Soils exposed for a longer time tended to have greater concentrations of soluble salts and possess sandier textures. Total organic C (3.59 g kg{sup −1}), total N (2.31 g kg{sup −1}) and labile C (1.83 g kg{sup −1}) tended to be lower near the glacier front compared with sites away from it, which is correlated with decreasing degree of humification of the soil organic matter with exposure time. Soil CO{sub 2}-C emissions tended to increase with distance from the glacier front. On average, the presence of vegetation increased CO{sub 2}-C emissions by 440%, or the equivalent of 0.633 g of CO{sub 2}-C m{sup −2} h{sup −1}. Results suggest that newly exposed landsurfaces undergo soil formation with increasing labile C input from vegetation, accompanied by increasing soil CO{sub 2}-C emissions. Despite the importance of exposure time on CO{sub 2}-C production and emissions, there was no similar trend in soil N{sub 2}O-N production potentials as a function of glacial retreat. For N{sub 2}O, instead, the maximum production occurred in sites with the first stages of vegetation growth

  7. Functional and structural causes of forests productivity decay with age: experimental analysis of a chrono-sequence of maritime pine stands; Causes fonctionnelles et structurales du declin de productivite des forets avec l'age: analyse experimentale d'une chronosequence de peuplements de pin maritime

    Energy Technology Data Exchange (ETDEWEB)

    Delzon, S.

    2004-06-15

    The aim of this work was to understand the causes of forest growth decline with increasing age. We investigated changes in several eco-physiological parameters in a chrono-sequence of four even-aged maritime pine stands. Above-ground productivity declined by a factor of 2.5 from the youngest to the oldest stands. This decline was explained by a decrease of gross primary production, due to a decline in both stand leaf area and foliar productivity. Our measurements clearly showed a decrease in leaf-specific hydraulic conductance with increasing tree height (50% lower in 30 m trees than in 10 m trees). We also found that needle water potential was maintained above a minimum threshold value of -2.0 MPa independently of tree age and height. This hydraulic homeostasis occurred through a decline in leaf / sapwood area ratio (hydraulic compensation) and a decline in stomatal conductance (physiological compensation). Both the increased investment in non-productive versus productive tissues and stomatal closure may have contributed to the observed decrease in foliar productivity with increasing tree height. Consequently, over-storey transpiration was reduced by a factor of three between the 10-yr and the 91-yr old stands. Nevertheless, our findings suggest that the total ecosystem evaporation remains constant in ageing forests due to an increase in under-storey transpiration, which may counterbalance the decrease in tree transpiration. Photosynthetic capacity also decreased in older stands, mainly through a decline in phosphorus concentration. Our results support the hypothesis that the age-related decline in forest growth is associated with decreased availability of the most limiting resource, this being phosphorus for the maritime Pine chrono-sequence investigated. (author)

  8. Impact of Nitrogen Fertilization on Forest Carbon Sequestration and Water Loss in a Chronosequence of Three Douglas-Fir Stands in the Pacific Northwest

    Directory of Open Access Journals (Sweden)

    Xianming Dou

    2015-05-01

    Full Text Available To examine the effect of nitrogen (N fertilization on forest carbon (C sequestration and water loss, we used an artificial neural network model to estimate C fluxes and evapotranspiration (ET in response to N fertilization during four post-fertilization years in a Pacific Northwest chronosequence of three Douglas-fir stands aged 61, 22 and 10 years old in 2010 (DF49, HDF88 and HDF00, respectively. Results showed that N fertilization increased gross primary productivity (GPP for all three sites in all four years with the largest absolute increase at HDF00 followed by HDF88. Ecosystem respiration increased in all four years at HDF00, but decreased over the last three years at HDF88 and over all four years at DF49. As a result, fertilization increased the net ecosystem productivity of all three stands with the largest increase at HDF88, followed by DF49. Fertilization had no discernible effect on ET in any of the stands. Consequently, fertilization increased water use efficiency (WUE in all four post-fertilization years at all three sites and also increased light use efficiency (LUE of all the stands, especially HDF00. Our results suggest that the effects of fertilization on forest C sequestration and water loss may be associated with stand age and fertilization; the two younger stands appeared to be more efficient than the older stand with respect to GPP, WUE and LUE.

  9. Long-term rice cultivation stabilizes soil organic carbon and promotes soil microbial activity in a salt marsh derived soil chronosequence

    Science.gov (United States)

    Wang, Ping; Liu, Yalong; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Joseph, Stephen; Pan, Genxing

    2015-01-01

    Soil organic carbon (SOC) sequestration with enhanced stable carbon storage has been widely accepted as a very important ecosystem property. Yet, the link between carbon stability and bio-activity for ecosystem functioning with OC accumulation in field soils has not been characterized. We assessed the changes in microbial activity versus carbon stability along a paddy soil chronosequence shifting from salt marsh in East China. We used mean weight diameter, normalized enzyme activity (NEA) and carbon gain from straw amendment for addressing soil aggregation, microbial biochemical activity and potential C sequestration, respectively. In addition, a response ratio was employed to infer the changes in all analyzed parameters with prolonged rice cultivation. While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils. Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization. This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation. However, the mechanism underpinning these changes should be explored in future studies in rice soils where dynamic redox conditions exist. PMID:26503629

  10. Nonnative invasive plants in the Penobscot Experimental Forest in Maine, USA: influence of site, silviculture, and land use history

    Science.gov (United States)

    Elizabeth Olson; Laura S. Kenefic; Alison C. Dibble; John C. Brissette

    2011-01-01

    We investigated the occurrence of nonnative invasive plants on approximately 175 ha comprising a long-term, 60-year-old U.S. Forest Service silvicultural experiment and old-field stands in the Penobscot Experimental Forest (PEF) in central Maine. Stands in the silvicultural experiment were never cleared for agriculture, but have been repeatedly partially cut. Our...

  11. Changes in wind erosion over a 25-year restoration chronosequence on the south edge of the Tengger Desert, China: implications for preventing desertification.

    Science.gov (United States)

    Ma, Quanlin; Fehmi, Jeffrey S; Zhang, Dekui; Fan, Baoli; Chen, Fang

    2017-08-23

    Wind erosion is a primary cause of desertification as well as being a serious ecological problem in arid and semi-arid areas across the world. To determine mechanisms for restoring desertified lands, an unrestored shifting sand dune and three formerly shifting sand dunes (desertified lands) that had been enclosed and afforested for 5, 15, and 25 years were selected for evaluation on the south edge of the Tengger Desert, China. Based on sampling heights between 0.2 and 3 m, the critical threshold average wind speed was 6.5 m s -1 at 2 m where the sand transport rate was reduced from 285.9 kg m -2  h -1 on the unrestored dunes to 9.1 and 1.8 kg m -2  h -1 on the sites afforested and enclosed for 5 and 15 years, respectively. The percentage of wind eroded area was reduced from 99.9% on the unrestored dune to 94.5, 9.0, and 0.5% on the sites afforested and enclosed for 5, 15, and 25 years, respectively. Wind erosion was effectively reduced after 15 years. Although there were different driving factors for wind erosion mitigation on the different restoration stages, an increase in the vegetation cover, surface roughness, soil shear strength, soil clay content, organic matter, and reduction in the near-surface wind speed were the primary variables associated with the restoration chronosequence. We conclude that reducing the wind speed and developing a biological crust through vegetation restoration were the critical components for restoration of desertified land.

  12. Succession of Bacterial Community Structure and Diversity in Soil along a Chronosequence of Reclamation and Re-Vegetation on Coal Mine Spoils in China

    Science.gov (United States)

    Li, Yuanyuan; Wen, Hongyu; Chen, Longqian; Yin, Tingting

    2014-01-01

    The growing concern about the effectiveness of reclamation strategies has motivated the evaluation of soil properties following reclamation. Recovery of belowground microbial community is important for reclamation success, however, the response of soil bacterial communities to reclamation has not been well understood. In this study, PCR-based 454 pyrosequencing was applied to compare bacterial communities in undisturbed soils with those in reclaimed soils using chronosequences ranging in time following reclamation from 1 to 20 year. Bacteria from the Proteobacteria, Chloroflexi, Actinobacteria, Acidobacteria, Planctomycetes and Bacteroidetes were abundant in all soils, while the composition of predominant phyla differed greatly across all sites. Long-term reclamation strongly affected microbial community structure and diversity. Initial effects of reclamation resulted in significant declines in bacterial diversity indices in younger reclaimed sites (1, 8-year-old) compared to the undisturbed site. However, bacterial diversity indices tended to be higher in older reclaimed sites (15, 20-year-old) as recovery time increased, and were more similar to predisturbance levels nearly 20 years after reclamation. Bacterial communities are highly responsive to soil physicochemical properties (pH, soil organic matter, Total N and P), in terms of both their diversity and community composition. Our results suggest that the response of soil microorganisms to reclamation is likely governed by soil characteristics and, indirectly, by the effects of vegetation restoration. Mixture sowing of gramineae and leguminosae herbage largely promoted soil geochemical conditions and bacterial diversity that recovered to those of undisturbed soil, representing an adequate solution for soil remediation and sustainable utilization for agriculture. These results confirm the positive impacts of reclamation and vegetation restoration on soil microbial diversity and suggest that the most important

  13. Soil data from fire and permafrost-thaw chronosequences in upland Picea mariana stands near Hess Creek and Tok, interior Alaska

    Science.gov (United States)

    O'Donnell, Jonathan A.; Harden, Jennifer W.; Manies, Kristen L.; Jorgenson, M. Torre; Kanevskiy, Mikhail; Xu, Xiaomei

    2013-01-01

    Soils of the Northern Circumpolar Permafrost region harbor 1,672 petagrams (Pg) (1 Pg = 1,000,000,000 kilograms) of organic carbon (OC), nearly 50 percent of the global belowground OC pool (Tarnocai and others, 2009). Of that soil OC, nearly 88 percent is presently stored in perennially frozen ground. Recent climate warming at northern latitudes has resulted in warming and thawing of permafrost in many regions (Osterkamp, 2007), which might mobilize OC stocks from associated soil reservoirs via decomposition, leaching, or erosion. Warming also has increased the magnitude and severity of wildfires in the boreal region (Turetsky and others, 2011), which might exacerbate rates of permafrost degradation relative to warming alone. Given the size and vulnerability of the soil OC pool in permafrost soils, permafrost thaw will likely function as a strong positive feedback to the climate system (Koven and others, 2011; Schaefer and others, 2011). In this report, we report soil OC inventories from two upland fire chronosequences located near Hess Creek and Tok in Interior Alaska. We sampled organic and mineral soils in the top 2 meters (m) across a range of stand ages to evaluate the effects of wildfire and permafrost thaw on soil C dynamics. These data were used to parameterize a simple process-based fire-permafrost-carbon model, which is described in detail by O’Donnell and others (2011a, b). Model simulations examine long-term changes in soil OC storage in response to fire, permafrost thaw, and climate change. These data also have been used in other papers, including Harden and others (2012), which examines C recovery post-fire, and Johnson and others (2011), which synthesizes data within the Alaska Soil Carbon Database. Findings from these studies highlight the importance of climate and disturbance (wildfire, permafrost thaw) on soil C storage, and loss of soil C from high-latitude ecosystems.

  14. A Simple and Effective Image Normalization Method to Monitor Boreal Forest Change in a Siberian Burn Chronosequence across Sensors and across Time

    Science.gov (United States)

    Chen, X.; Vierling, L. A.; Deering, D. W.

    2004-12-01

    Satellite data offer unique perspectives for monitoring and quantifying land cover change, however, the radiometric consistency among co-located multi-temporal images is difficult to maintain due to variations in sensors and atmosphere. To detect accurate landscape change using multi-temporal images, we developed a new relative radiometric normalization scheme: the temporally invariant cluster (TIC) method. Image data were acquired on 9 June 1990 (Landsat 4), 20 June 2000, and 26 August 2001 (Landsat 7) for analyses over boreal forests near the Siberian city of Krasnoyarsk. Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and Reduced Simple Ratio (RSR) were investigated in the normalization study. The temporally invariant cluster (TIC) centers were identified through a point density map of the base image and the target image and a normalization regression line was created through all TIC centers. The target image digital data were then converted using the regression function so that the two images could be compared using the resulting common radiometric scale. We found that EVI was very sensitive to vegetation structure and could thus be used to separate conifer forests from deciduous forests and grass/crop lands. NDVI was a very effective vegetation index to reduce the influence of shadow, while EVI was very sensitive to shadowing. After normalization, correlations of NDVI and EVI with field collected total Leaf Area Index (LAI) data in 2000 and 2001 were significantly improved; the r-square values in these regressions increased from 0.49 to 0.69 and from 0.46 to 0.61, respectively. An EVI ¡°cancellation effect¡± where EVI was positively related to understory greenness but negatively related to forest canopy coverage was evident across a post fire chronosequence. These findings indicate that the TIC method provides a simple, effective and repeatable method to create radiometrically comparable data sets for remote detection of

  15. Chemical weathering of a marine terrace chronosequence, Santa Cruz, California I: Interpreting rates and controls based on soil concentration-depth profiles

    Science.gov (United States)

    White, A.F.; Schulz, M.S.; Vivit, D.V.; Blum, A.E.; Stonestrom, David A.; Anderson, S.P.

    2008-01-01

    The spatial and temporal changes in element and mineral concentrations in regolith profiles in a chronosequence developed on marine terraces along coastal California are interpreted in terms of chemical weathering rates and processes. In regoliths up to 15 m deep and 226 kyrs old, quartz-normalized mass transfer coefficients indicate non-stoichiometric preferential release of Sr > Ca > Na from plagioclase along with lesser amounts of K, Rb and Ba derived from K-feldspar. Smectite weathering results in the loss of Mg and concurrent incorporation of Al and Fe into secondary kaolinite and Fe-oxides in shallow argillic horizons. Elemental losses from weathering of the Santa Cruz terraces fall within the range of those for other marine terraces along the Pacific Coast of North America. Residual amounts of plagioclase and K-feldspar decrease with terrace depth and increasing age. The gradient of the weathering profile bs is defined by the ratio of the weathering rate, R to the velocity at which the profile penetrates into the protolith. A spreadsheet calculator further refines profile geometries, demonstrating that the non-linear regions at low residual feldspar concentrations at shallow depth are dominated by exponential changes in mineral surface-to-volume ratios and at high residual feldspar concentrations, at greater depth, by the approach to thermodynamic saturation. These parameters are of secondary importance to the fluid flux qh, which in thermodynamically saturated pore water, controls the weathering velocity and mineral losses from the profiles. Long-term fluid fluxes required to reproduce the feldspar weathering profiles are in agreement with contemporary values based on solute Cl balances (qh = 0.025-0.17 m yr-1). During saturation-controlled and solute-limited weathering, the greater loss of plagioclase relative to K-feldspar is dependent on the large difference in their respective solubilities instead of the small difference between their respective

  16. Long-term controls of soil organic carbon with depth and time: a case study from the Cowlitz River Chronosequence, WA USA

    Science.gov (United States)

    Lawrence, Corey R.; Harden, Jennifer W.; Xu, Xiaomei; Schulz, Marjorie S.; Trumbore, Susan E.

    2015-01-01

    Over timescales of soil development (millennia), the capacity of soils to stabilize soil organic carbon (SOC) is linked to soil development through changes in soil mineralogy and other soil properties. In this study, an extensive dataset of soil profile chemistry and mineralogy is compiled from the Cowlitz River Chronosequence (CRC), WA USA. The CRC soils range in age from 0.25 to 1200 kyr, spanning a developmental gradient encompassing clear changes in soil mineralogy, chemistry, and surface area. Comparison of these and other metrics of soil development with SOC properties reveal several relationships that may be diagnostic of the long-term coupling of soil development and C cycling. Specifically, SOC content was significantly correlated with sodium pyrophosphate extractable metals emphasizing the relevance of organo-metal complexes in volcanic soils. The depth distributions of organo-metals and other secondary weathering products, including the kaolin and short-range order (SRO) minerals, support the so-called “binary composition” of volcanic soils. The formation of organo-metal complexes limits the accumulation of secondary minerals in shallow soils, whereas in deep soils with lower SOC content, secondary minerals accumulate. In the CRC soils, secondary minerals formed in deep soils (below 50 cm) including smectite, allophane, Fe-oxides and dominated by the kaolin mineral halloysite. The abundance of halloysite was significantly correlated with bulk soil surface area and 14C content (a proxy for the mean age of SOC), implying enhanced stability of C in deep soils. Allophane, an SRO mineral commonly associated with SOC storage, was not correlated with SOC content or 14C values in CRC soils. We propose conceptual framework to describe these observations based on a general understanding of pedogenesis in volcanic soils, where SOC cycling is coupled with soil development through the formation of and fate of organo-metal or other mobile weathering products

  17. Elemental composition and optical properties reveal changes in dissolved organic matter along a permafrost thaw chronosequence in a subarctic peatland

    Energy Technology Data Exchange (ETDEWEB)

    Hodgkins, Suzanne; Tfaily, Malak M.; Podgorski, David C.; McCalley, Carmody; Saleska, Scott; Crill, Patrick M.; Rich, Virginia; Chanton, Jeffrey; Cooper, William T.

    2016-08-01

    The fate of carbon stored in permafrost-zone peatlands represents a significant uncertainty in global climate modeling. Given that the breakdown of dissolved organic matter (DOM) is often a major pathway for decomposition in peatlands, knowledge of DOM reactivity under different permafrost regimes is critical for determining future climate feedbacks. To explore the effects of permafrost thaw and resultant plant succession on DOM reactivity, we used a combination of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), UV/Vis absorbance, and excitation-emission matrix spectroscopy (EEMS) to examine the DOM elemental composition and optical properties of 27 pore water samples gathered from various sites along a permafrost thaw sequence in Stordalen Mire, a thawing subarctic peatland in northern Sweden. The presence of dense Sphagnum moss, a feature that is dominant in the intermediate thaw stages, appeared to be the main driver of variation in DOM elemental composition and optical properties at Stordalen. Specifically, DOM from sites with Sphagnum had greater aromaticity, higher average molecular weights, and greater O/C, consistent with a higher abundance of phenolic compounds that likely inhibit decomposition. These compounds are released by Sphagnum and may accumulate due to inhibition of phenol oxidase activity by the acidic pH at these sites. In contrast, sites without Sphagnum, specifically fully-thawed rich fens, had more saturated, more reduced compounds, which were high in N and S. Optical properties at rich fens were indicated the presence of microbially-derived DOM, consistent with the higher decomposition rates previously measured at these sites. These results indicate that Sphagnum acts as an inhibitor of rapid decomposition and CH4 release in thawing subarctic peatlands, consistent with lower rates of CO2 and CH4 production previously observed at these sites. However, this inhibitory effect may disappear if Sphagnumdominated bogs

  18. Elemental composition and optical properties reveal changes in dissolved organic matter along a permafrost thaw chronosequence in a subarctic peatland

    Science.gov (United States)

    Hodgkins, Suzanne B.; Tfaily, Malak M.; Podgorski, David C.; McCalley, Carmody K.; Saleska, Scott R.; Crill, Patrick M.; Rich, Virginia I.; Chanton, Jeffrey P.; Cooper, William T.

    2016-08-01

    The fate of carbon stored in permafrost-zone peatlands represents a significant uncertainty in global climate modeling. Given that the breakdown of dissolved organic matter (DOM) is often a major pathway for decomposition in peatlands, knowledge of DOM reactivity under different permafrost regimes is critical for determining future climate feedbacks. To explore the effects of permafrost thaw and resultant plant succession on DOM reactivity, we used a combination of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), UV/Vis absorbance, and excitation-emission matrix spectroscopy (EEMS) to examine the DOM elemental composition and optical properties of 27 pore water samples gathered from various sites along a permafrost thaw sequence in Stordalen Mire, a thawing subarctic peatland in northern Sweden. The presence of dense Sphagnum moss, a feature that is dominant in the intermediate thaw stages, appeared to be the main driver of variation in DOM elemental composition and optical properties at Stordalen. Specifically, DOM from sites with Sphagnum had greater aromaticity, higher average molecular weights, and greater O/C, consistent with a higher abundance of phenolic compounds that likely inhibit decomposition. These compounds are released by Sphagnum and may accumulate due to inhibition of phenol oxidase activity by the acidic pH at these sites. In contrast, sites without Sphagnum, specifically fully-thawed rich fens, had more saturated, more reduced compounds, which were high in N and S. Optical properties at rich fens indicated the presence of microbially-derived DOM, consistent with the higher decomposition rates previously measured at these sites. These results indicate that Sphagnum acts as an inhibitor of rapid decomposition and CH4 release in thawing subarctic peatlands, consistent with lower rates of CO2 and CH4 production previously observed at these sites. However, this inhibitory effect may disappear if Sphagnum-dominated bogs

  19. Response of photosynthetic carbon gain to ecosystem retrogression of vascular plants and mosses in the boreal forest.

    Science.gov (United States)

    Bansal, Sheel; Nilsson, Marie-Charlotte; Wardle, David A

    2012-07-01

    In the long-term absence of rejuvenating disturbances, forest succession frequently proceeds from a maximal biomass phase to a retrogressive phase characterized by reduced nutrient availability [notably nitrogen (N) and phosphorus (P)] and net primary productivity. Few studies have considered how retrogression induces changes in ecophysiological responses associated with photosynthetic carbon (C) gain, and only for trees. We tested the hypothesis that retrogression would negatively impact photosynthetic C gain of four contrasting species, and that this impact would be greater for vascular plants (i.e., trees and shrubs) than for non-vascular plants (i.e., mosses). We used a 5,000-year-old chronosequence of forested islands in Sweden, where retrogression occurs in the long-term absence of lightning-ignited wildfires. Despite fundamental differences in plant form and ecological niche among species, vascular plants and mosses showed similar ecophysiological responses to retrogression. The most common effects of retrogression were reductions in photosynthesis and respiration per unit foliar N, increases in foliar N, δ(13)C and δ(15)N, and decreases in specific leaf areas. In contrast, photosynthesis per unit mass or area generally did not change along the chronosequence, but did vary many-fold between vascular plants and mosses. The consistent increases in foliar N without corresponding increases in mass- or area-based photosynthesis suggest that other factor(s), such as P co-limitation, light conditions or water availability, may co-regulate C gain in retrogressive boreal forests. Against our predictions, traits of mosses associated with C and N were generally highly responsive to retrogression, which has implications for how mosses influence ecosystem processes in boreal forests.

  20. Bottom-up and top-down effects on plant communities

    DEFF Research Database (Denmark)

    Souza, Lara; Zelikova, Tamara Jane; Sanders, Nate

    2016-01-01

    -down) and soil nitrogen (bottom-up) were manipulated over six years in an existing old-field community. We tracked plant α and β diversity - within plot richness and among plot biodiversity- and aboveground net primary productivity (ANPP) over the course of the experiment. We found that bottom-up factors...... affected ANPP while top-down factors influenced plant community structure. Across years, while N reduction lowered ANPP by 10%, N reduction did not alter ANPP relative to control plots. Further, N reduction lowered ANPP by 20% relative to N addition plots. On the other hand, the reduction of insect...... community composition via shifts in plant dominance....

  1. Facilitation among plants in alpine environments in the face of climate change.

    Science.gov (United States)

    Anthelme, Fabien; Cavieres, Lohengrin A; Dangles, Olivier

    2014-01-01

    While there is a large consensus that plant-plant interactions are a crucial component of the response of plant communities to the effects of climate change, available data remain scarce, particularly in alpine systems. This represents an important obstacle to making consistent predictions about the future of plant communities. Here, we review current knowledge on the effects of climate change on facilitation among alpine plant communities and propose directions for future research. In established alpine communities, while warming seemingly generates a net facilitation release, earlier snowmelt may increase facilitation. Some nurse plants are able to buffer microenvironmental changes in the long term and may ensure the persistence of other alpine plants through local migration events. For communities migrating to higher elevations, facilitation should play an important role in their reorganization because of the harsher environmental conditions. In particular, the absence of efficient nurse plants might slow down upward migration, possibly generating chains of extinction. Facilitation-climate change relationships are expected to shift along latitudinal gradients because (1) the magnitude of warming is predicted to vary along these gradients, and (2) alpine environments are significantly different at low vs. high latitudes. Data on these expected patterns are preliminary and thus need to be tested with further studies on facilitation among plants in alpine environments that have thus far not been considered. From a methodological standpoint, future studies will benefit from the spatial representation of the microclimatic environment of plants to predict their response to climate change. Moreover, the acquisition of long-term data on the dynamics of plant-plant interactions, either through permanent plots or chronosequences of glacial recession, may represent powerful approaches to clarify the relationship between plant interactions and climate change.

  2. Forest Fires Darken Snow for Years following Disturbance: Magnitude, Duration, and Composition of Light Absorbing Impurities in Seasonal Snow across a Chronosequence of Burned Forests in the Colorado River Headwaters

    Science.gov (United States)

    Gleason, K. E.; Arienzo, M. M.; Chellman, N.; McConnell, J.

    2017-12-01

    Charred forests shed black carbon and burned debris, which accumulates and concentrates on winter snowpack, reducing snow surface albedo, and subsequently increasing snowmelt rates, and advancing the date of snow disappearance. Forest fires have occurred across vast areas of the seasonal snow zone in recent decades, however we do not understand the long-term implications of burned forests in montane headwaters to snow hydrology and downstream water resources. Across a chronosequence of nine burned forests in the Colorado River Headwaters, we sampled snow throughout the complete snowpack profile to conserve the composition, properties, and vertical stratigraphy of impurities in the snowpack during maximum snow accumulation. Using state-of-the-art geochemical analyses, we determined the magnitude, composition, and particle size distribution of black carbon, dust, and other impurities in the snowpack relative to years-since fire. Forest fires continue to darken snow for many years following fire, however the magnitude, composition, and particle size distribution of impurities change through time, altering the post-fire radiative forcing on snow as a burned forest ages.

  3. Facilitation among plants in alpine environments in the face of climate change

    Directory of Open Access Journals (Sweden)

    Fabien eAnthelme

    2014-08-01

    Full Text Available While there is a large consensus that plant–plant interactions are a crucial component of the response of plant communities to the effects of climate change, available data remain scarce, particularly in alpine systems. This represents an important obstacle to making consistent predictions about the future of plant communities. Here, we review current knowledge on the effects of climate change on facilitation among alpine plant communities and propose directions for future research. In established alpine communities, while warming seemingly generates a net facilitation release, earlier snowmelt may increase facilitation. Some nurse plants are able to buffer microenvironmental changes in the long term and may ensure the persistence of other alpine plants through local migration events. For communities migrating to higher elevations, facilitation should play an important role in their reorganization because of the harsher environmental conditions. In particular, the absence of efficient nurse plants might slow down upward migration, possibly generating chains of extinction. Facilitation–climate change relationships are expected to shift along latitudinal gradients because (1 the magnitude of warming is predicted to vary along these gradients, and (2 alpine environments are significantly different at low vs. high latitudes. Data on these expected patterns are preliminary and thus need to be tested with further studies on facilitation among plants in alpine environments that have thus far not been considered. From a methodological standpoint, future studies will benefit from the spatial representation of the microclimatic environment of plants to predict their response to climate change. Moreover, the acquisition of long-term data on the dynamics of plant–plant interactions, either through permanent plots or chronosequences of glacial recession, may represent powerful approaches to clarify the relationship between plant interactions and

  4. Zonnic®: a new player in an old field.

    Science.gov (United States)

    Gong, Min; Dunbar, Michael S; Setodji, Claude; Shadel, William G

    2017-09-06

    The tobacco industry is continually evolving to adapt to increasing tobacco control pressure and regulation, and to cater to consumer preferences. Recently, RJ Reynolds rolled-out a nicotine-containing gum, Zonnic®, which is marketed as a smoking cessation and reduction product and is sold at convenience stores at a lower price and in a smaller quantity than existing brands sold at pharmacies. The introduction of Zonnic® products is a critical first step in tobacco industry's involvement in the NRT market and a serious indication of the evolving tobacco and nicotine-delivery industry and environment. It is likely that this trend will continue and spread, and as such, have a significant impact at multiple dimensions, including consumer perceptions and behavior, tobacco and NRT industry business strategy, and regulation and policy. In this special communication, we present an overview of the current marketing strategy for Zonnic®, discuss its potential impacts at the market level and at the level of the individual consumer, and suggest research and policy priorities based on the magnitude and urgency of the impacts.

  5. 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.

  6. Roadside soils show low plant available zinc and copper concentrations.

    Science.gov (United States)

    Morse, Natalie; Walter, M Todd; Osmond, Deanna; Hunt, William

    2016-02-01

    Vehicle combustion and component wear are a major source of metal contamination in the environment, which could be especially concerning where road ditches are actively farmed. The objective of this study was to assess how site variables, namely age, traffic (vehicles day(-1)), and percent carbon (%C) affect metal accumulation in roadside soils. A soil chronosequence was established with sites ranging from 3 to 37 years old and bioavailable, or mobile, concentrations of Zinc (Zn) and Copper (Cu) were measured along major highways in North Carolina using a Mehlich III extraction. Mobile Zn and Cu concentrations were low overall, and when results were scaled via literature values to "total metal", the results were still generally lower than previous roadside studies. This could indicate farming on lands near roads would pose a low plant toxicity risk. Zinc and Cu were not correlated with annual average traffic count, but were positively correlated with lifetime traffic load (the product of site age and traffic count). This study shows an often overlooked variable, site age, should be included when considering roadside pollution accumulation. Zinc and Cu were more strongly associated with %C, than traffic load. Because vehicle combustion is also a carbon source, it is not obvious whether the metals and carbon are simply co-accumulating or whether the soil carbon in roadside soils may facilitate previously overlooked roles in sequestering metals on-site. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Plant Communities Rather than Soil Properties Structure Arbuscular Mycorrhizal Fungal Communities along Primary Succession on a Mine Spoil

    Science.gov (United States)

    Krüger, Claudia; Kohout, Petr; Janoušková, Martina; Püschel, David; Frouz, Jan; Rydlová, Jana

    2017-01-01

    Arbuscular mycorrhizal fungal (AMF) community assembly during primary succession has so far received little attention. It remains therefore unclear, which of the factors, driving AMF community composition, are important during ecosystem development. We addressed this question on a large spoil heap, which provides a mosaic of sites in different successional stages under different managements. We selected 24 sites of c. 12, 20, 30, or 50 years in age, including sites with spontaneously developing vegetation and sites reclaimed by alder plantations. On each site, we sampled twice a year roots of the perennial rhizomatous grass Calamagrostis epigejos (Poaceae) to determine AMF root colonization and diversity (using 454-sequencing), determined the soil chemical properties and composition of plant communities. AMF taxa richness was unaffected by site age, but AMF composition variation increased along the chronosequences. AMF communities were unaffected by soil chemistry, but related to the composition of neighboring plant communities of the sampled C. epigejos plants. In contrast, the plant communities of the sites were more distinctively structured than the AMF communities along the four successional stages. We conclude that AMF and plant community successions respond to different factors. AMF communities seem to be influenced by biotic rather than by abiotic factors and to diverge with successional age. PMID:28473828

  8. Roadside soils show low plant available zinc and copper concentrations

    International Nuclear Information System (INIS)

    Morse, Natalie; Walter, M. Todd; Osmond, Deanna; Hunt, William

    2016-01-01

    Vehicle combustion and component wear are a major source of metal contamination in the environment, which could be especially concerning where road ditches are actively farmed. The objective of this study was to assess how site variables, namely age, traffic (vehicles day"−"1), and percent carbon (%C) affect metal accumulation in roadside soils. A soil chronosequence was established with sites ranging from 3 to 37 years old and bioavailable, or mobile, concentrations of Zinc (Zn) and Copper (Cu) were measured along major highways in North Carolina using a Mehlich III extraction. Mobile Zn and Cu concentrations were low overall, and when results were scaled via literature values to “total metal”, the results were still generally lower than previous roadside studies. This could indicate farming on lands near roads would pose a low plant toxicity risk. Zinc and Cu were not correlated with annual average traffic count, but were positively correlated with lifetime traffic load (the product of site age and traffic count). This study shows an often overlooked variable, site age, should be included when considering roadside pollution accumulation. Zinc and Cu were more strongly associated with %C, than traffic load. Because vehicle combustion is also a carbon source, it is not obvious whether the metals and carbon are simply co-accumulating or whether the soil carbon in roadside soils may facilitate previously overlooked roles in sequestering metals on-site. - Highlights: • Low plant available zinc and copper concentrations in roadside soils of the southeast U.S. • Metals from vehicular traffic may not be adversely affecting plants in roadside environment. • Traffic volume and site age better predictor of metal pollution than traffic volume alone. - Mobile concentrations of Zn and Cu in roadside soils were below toxic levels. Zn and Cu concentrations were better correlated with lifetime vehicle load, as opposed to traffic volume.

  9. Unprecedented carbon accumulation in mined soils: the synergistic effect of resource input and plant species invasion.

    Science.gov (United States)

    Silva, Lucas C R; Corrêa, Rodrigo S; Doane, Timothy A; Pereira, Engil I P; Horwath, William R

    2013-09-01

    Opencast mining causes severe impacts on natural environments, often resulting in permanent damage to soils and vegetation. In the present study we use a 14-year restoration chronosequence to investigate how resource input and spontaneous plant colonization promote the revegetation and reconstruction of mined soils in central Brazil. Using a multi-proxy approach, combining vegetation surveys with the analysis of plant and soil isotopic abundances (delta13C and delta15N) and chemical and physical fractionation of organic matter in soil profiles, we show that: (1) after several decades without vegetation cover, the input of nutrient-rich biosolids into exposed regoliths prompted the establishment of a diverse plant community (> 30 species); (2) the synergistic effect of resource input and plant colonization yielded unprecedented increases in soil carbon, accumulating as chemically stable compounds in occluded physical fractions and reaching much higher levels than observed in undisturbed ecosystems; and (3) invasive grasses progressively excluded native species, limiting nutrient availability, but contributing more than 65% of the total accumulated soil organic carbon. These results show that soil-plant feedbacks regulate the amount of available resources, determining successional trajectories and alternative stable equilibria in degraded areas undergoing restoration. External inputs promote plant colonization, soil formation, and carbon sequestration, at the cost of excluding native species. The introduction of native woody species would suppress invasive grasses and increase nutrient availability, bringing the system closer to its original state. However, it is difficult to predict whether soil carbon levels could be maintained without the exotic grass cover. We discuss theoretical and practical implications of these findings, describing how the combination of resource manipulation and management of invasive species could be used to optimize restoration strategies

  10. Effects of Nonnative Ungulate Removal on Plant Communities and Soil Biogeochemistry in Tropical Forests

    Science.gov (United States)

    Cole, R. J.; Litton, C. M.; Giardina, C. P.; Sparks, J. P.

    2014-12-01

    Non-native ungulates have substantial impacts on native ecosystems globally, altering both plant communities and soil biogeochemistry. Across tropical and temperate ecosystems, land managers fence and remove non-native ungulates to conserve native biodiversity, a costly management action, yet long-term outcomes are not well quantified. Specifically, knowledge gaps include: (i) the magnitude and time frame of plant community recovery; (ii) the response of non-native invasive plants; and (iii) changes to soil biogeochemistry. In 2010, we established a series of paired ungulate presence vs. removal plots that span a 20 yr. chronosequence in tropical montane wet forests on the Island of Hawaii to quantify the impacts and temporal legacy of feral pig removal on plant communities and soil biogeochemistry. We also compared soil biogeochemistry in targeted areas of low and high feral pig impact. Our work shows that both native and non-native vegetation respond positively to release from top-down control following removal of feral pigs, but species of high conservation concern recover only if initially present at the time of non-native ungulate removal. Feral pig impacts on soil biogeochemistry appear to last for at least 20 years following ungulate removal. We observed that both soil physical and chemical properties changed with feral pig removal. Soil bulk density and volumetric water content decreased while extractable base cations and inorganic N increased in low vs. high feral pig impact areas. We hypothesize that altered soil biogeochemistry facilitates continued invasions by non-native plants, even decades after non-native ungulate removal. Future work will concentrate on comparisons between wet and dry forest ecosystems and test whether manipulation of soil nutrients can be used to favor native vs. non-native plant establishment.

  11. Woody plant encroachment effect on soil organic carbon dynamics: results from a latitudinal gradient in Italy

    Science.gov (United States)

    Pellis, Guido; Chiti, Tommaso; Moscatelli, Maria Cristina; Marinari, Sara; Papale, Dario

    2016-04-01

    Woody plant encroachment into pastures and grasslands represents a significant land cover change phenomenon, with a considerable impact on carbon dynamics at an ecosystem level. It was estimated that 7.64% of the Southern Europe land was subject to that process between 1950 to 2010. As a result of woody encroachment, changes in vegetation composition can produce substantial changes to the soil organic carbon (SOC) cycle. Despite the numerous papers published on land-use change, an evaluation of the IPCC terrestrial carbon pools changes occurring during woody encroachment on abandoned pastures and grasslands is still lacking, particularly for the Italian territory. Therefore, the aim of this study was to investigate the role of woody encroachment on carbon sequestration over abandoned pastures and grasslands in Alpine and Apennine ecosystems, with a particular focus on the SOC. We applied a chronosequence approach to seven selected sites located along a latitudinal gradient in Italy. Each chronosequence consisted of a pasture currently managed, three sites abandoned at different times in the past and, finally, a mature forest stand representing the last phase of the succession. The European Commission sampling protocols to certify SOC changes was adopted to estimate the variations following woody encroachment. Soil samples were collected at different depths in the topsoil (0-30 cm) and subsoil (30-70 cm), despite the original protocol formulation being limited to the topsoil only. In addition, aboveground living biomass (AGB), dead wood and litter were also measured following international protocols. Considering all C pools together, woody plant encroachment leads to a progressive C stock accumulation in all the chronosequences. The total C stock of mature forest stands ranges from 1.78±0.11 times (Eastern Alps) to 2.48±0.31 times (central Apennine) the initial value on pastures. Unsurprisingly, the C stocks of AGB, dead wood and litter all increase during the

  12. Biochar and Ecosystem Restoration: Plant Ecophysiological Responses

    Science.gov (United States)

    Gale, N.; Halim, M. A.; Thomas, S. C.

    2017-12-01

    Charcoal is thought to facilitate rapid plant regeneration following fires by increasing the retention and availability of nutrients and water, increasing soil pH, and by sorbing toxic and inhibitory soil compounds - responses that have recently encouraged research on "biochar," or charcoal used as a soil amendment. Interest in biochar for use in the restoration of disturbed systems is growing; however, investigations of the effects of biochar on wild plants and trees are lacking. We present results from two experiments testing the influence of biochar on the growth and physiology of pioneers. In the first study, in a glasshouse, we examined the effects of maple biochar (10 and 20 t/ha) applied to a temperate managed forest soil on the ecophysiology of 13 herbaceous old-field species. In the second study, in field trials in Bangladesh (15 x 15 m plots), we examined the effects of acacia biochar (7.5 t/ha) on the growth of regenerating dipterocarp secondary forests. In both experiments, we measured changes in nutrient availability to help explain ecophysiological responses. Biochars enhanced the performance of early successional old-field pioneers: increasing aboveground biomass (37%), photosynthesis (17%), reproductive biomass (100%), and water use efficiency (44%), but with high species-specific variation that included negative responses. In tropical forests, biochars marginally improved the growth and recruitment of canopy dipterocarps and increased the photosynthetic performance and abundance of some, but not all, of the dominant understory species. In both experiments, growth enhancement was due to pulses of PO4-and K+ supplied by biochar in the short term; while null and negative responses were the result of nitrogen immobilization for species with high photosynthetic capacities. These results suggest that by providing a pulse of P and base cations, biochar can improve the restoration of disturbed landscapes by enhancing the physiological performance of

  13. Medicinal Plants.

    Science.gov (United States)

    Phillipson, J. David

    1997-01-01

    Highlights the demand for medicinal plants as pharmaceuticals and the demand for health care treatments worldwide and the issues that arise from this. Discusses new drugs from plants, anticancer drugs, antiviral drugs, antimalarial drugs, herbal remedies, quality, safety, efficacy, and conservation of plants. Contains 30 references. (JRH)

  14. 10Be accumulation in a soil chronosequence

    Science.gov (United States)

    Pavich, M.J.; Brown, L.; Klein, J.; Middleton, R.

    1984-01-01

    We have measured the concentration of the cosmogenic isotope 10Be in soil samples from various horizons at six sites, including three independently dated Rappahannock River terraces and a previously undated Piedmont soil to which we have assigned an age. All of the incident 10Be can be accounted for in one of these soils and a second is within a factor of two. In three soils, whose concentrations vary widely with depth, a significant fraction of the incident 10Be cannot be accounted for. Incomplete sampling, and enhanced Be mobility caused by organic components, are the probable reasons for the low inventory of Be from these three soils. Overall, the data from these six sites indicate that 10Be accumulation could be used to assign ages to soils if Be is not mobilized and lost from the soil profile. ?? 1984.

  15. Primary Succession on a Hawaiian Dryland Chronosequence.

    Directory of Open Access Journals (Sweden)

    Kealohanuiopuna M Kinney

    Full Text Available We used measurements from airborne imaging spectroscopy and LiDAR to quantify the biophysical structure and composition of vegetation on a dryland substrate age gradient in Hawaii. Both vertical stature and species composition changed during primary succession, and reveal a progressive increase in vertical stature on younger substrates followed by a collapse on Pleistocene-aged flows. Tall-stature Metrosideros polymorpha woodlands dominated on the youngest substrates (hundreds of years, and were replaced by the tall-stature endemic tree species Myoporum sandwicense and Sophora chrysophylla on intermediate-aged flows (thousands of years. The oldest substrates (tens of thousands of years were dominated by the short-stature native shrub Dodonaea viscosa and endemic grass Eragrostis atropioides. We excavated 18 macroscopic charcoal fragments from Pleistocene-aged substrates. Mean radiocarbon age was 2,002 years and ranged from < 200 to 7,730. Genus identities from four fragments indicate that Osteomeles spp. or M. polymorpha once occupied the Pleistocene-aged substrates, but neither of these species is found there today. These findings indicate the existence of fires before humans are known to have occupied the Hawaiian archipelago, and demonstrate that a collapse in vertical stature is prevalent on the oldest substrates. This work contributes to our understanding of prehistoric fires in shaping the trajectory of primary succession in Hawaiian drylands.

  16. Primary Succession on a Hawaiian Dryland Chronosequence

    OpenAIRE

    Kinney, Kealohanuiopuna M.; Asner, Gregory P.; Cordell, Susan; Chadwick, Oliver A.; Heckman, Katherine; Hotchkiss, Sara; Jeraj, Marjeta; Kennedy-Bowdoin, Ty; Knapp, David E.; Questad, Erin J.; Thaxton, Jarrod M.; Trusdell, Frank; Kellner, James R.

    2015-01-01

    We used measurements from airborne imaging spectroscopy and LiDAR to quantify the biophysical structure and composition of vegetation on a dryland substrate age gradient in Hawaii. Both vertical stature and species composition changed during primary succession, and reveal a progressive increase in vertical stature on younger substrates followed by a collapse on Pleistocene-aged flows. Tall-stature Metrosideros polymorpha woodlands dominated on the youngest substrates (hundreds of years), and ...

  17. Legacy effects of no-analogue disturbances alter plant community diversity and composition in semi-arid sagebrush steppe

    Science.gov (United States)

    Ripplinger, Julie; Franklin, Janet; Edwards, Thomas C.

    2015-01-01

    Questions(i) What role does the type of managed disturbance play in structuring sagebrush steppe plant communities? (ii) How does the composition of post-disturbance plant communities change with time since disturbance? (iii) Does plant community diversity change over time following managed disturbance?LocationField study within the sagebrush steppe ecosystem. Rich County, Utah, USA.MethodsWe developed a chronosequence spanning up to 50 yrs post-treatment to study sagebrush steppe vegetation dynamics. Direct ordination was used to examine plant community composition by managed disturbance type and time since disturbance, and factorial analysis of covariance was used to examine diversity dynamics following disturbance. Indicator species values were calculated in order to identify characteristic species for each disturbance type.ResultsPlant communities experienced a shift toward distinct community composition for each of the three managed disturbance types, and gave no indication of returning to untreated community composition or diversity. Small post-disturbance increases in the number of non-native grass species were observed in the treatments relative to reference, with native forb species making the largest contribution to altered composition. On fire- and chemically-treated sites the proportional native forb species richness increased over time since disturbance, while the proportional contribution of non-native forbs to total species richness decreased. For all three treatment types, native grasses contributed less on average to total richness than on reference sites, while non-native grasses made up a higher proportion of total richness.ConclusionsCommon shrubland management techniques have legacy effects on the composition and diversity of sagebrush steppe plant communities, and no-analogue disturbances, such as chemical or mechanical treatments, have more pronounced legacy effects than treatments similar to natural disturbance regimes (fire). This study

  18. Plant walkdown

    International Nuclear Information System (INIS)

    Kostov, M.

    2000-01-01

    This report covers the following: preparatory steps for performing plant walk-down; the objective of the first plant walk-down; plant walk-down procedures; earthquake screening evaluation; walk-down documentation; second plant walk-down. The following objectives concerning the plant walk-down(s) were achieved. The plant system configuration is verified in order to proceed with event tree and fault tree analyses. Systems interactions, other types of dependencies or plant unique features are identified. he safety related components that are judged to generically possess high capacities (i.e., larger than the earthquake review level) have been verified to contain no weaknesses. Further analyses needed to establish the capacities of remaining safety-related components are identified and necessary field data are obtained. Information on components is obtained to assist in HCLPF (fragility) evaluation and peer review of the seismic margin study

  19. Aquatic plants

    DEFF Research Database (Denmark)

    Madsen, T. V.; Sand-Jensen, K.

    2006-01-01

    Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between terre...... terrestrial and aquatic environments continues today and is very intensive along stream banks. In this chapter we describe the physical and chemical barriers to the exchange of plants between land and water.......Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between...

  20. Electronic plants

    Science.gov (United States)

    Stavrinidou, Eleni; Gabrielsson, Roger; Gomez, Eliot; Crispin, Xavier; Nilsson, Ove; Simon, Daniel T.; Berggren, Magnus

    2015-01-01

    The roots, stems, leaves, and vascular circuitry of higher plants are responsible for conveying the chemical signals that regulate growth and functions. From a certain perspective, these features are analogous to the contacts, interconnections, devices, and wires of discrete and integrated electronic circuits. Although many attempts have been made to augment plant function with electroactive materials, plants’ “circuitry” has never been directly merged with electronics. We report analog and digital organic electronic circuits and devices manufactured in living plants. The four key components of a circuit have been achieved using the xylem, leaves, veins, and signals of the plant as the template and integral part of the circuit elements and functions. With integrated and distributed electronics in plants, one can envisage a range of applications including precision recording and regulation of physiology, energy harvesting from photosynthesis, and alternatives to genetic modification for plant optimization. PMID:26702448

  1. Plant and soil carbon accumulation following fire in Mediterranean woodlands in Spain.

    Science.gov (United States)

    Kaye, Jason Philip; Romanyà, Joan; Vallejo, V Ramón

    2010-10-01

    We measured plant and soil carbon (C) storage following canopy-replacing wildfires in woodlands of northeastern Spain that include an understory of shrubs dominated by Quercus coccifera and an overstory of Pinus halepensis trees. Established plant succession models predict rapid shrub recovery in these ecosystems, and we build on this model by contrasting shrub succession with long-term C storage in soils, trees, and the whole ecosystem. We used chronosequence and repeated sampling approaches to detect change over time. Aboveground plant C increased from fire, which is substantially less than the 5,942 ± 487 g C m(-2) (mean ±1 standard error) in unburned sites. As expected, shrubs accumulated C rapidly, but the capacity for C storage in shrubs was 20 years post fire, and accounted for all of the difference in plant C between older burned sites and unburned sites. In contrast, soil C was initially higher in burned sites (~4,500 g C m(-2)) than in unburned sites (3,264 ± 261 g C m(-2)) but burned site C declined to unburned levels within 10 years after fire. Combining these results with prior research suggests two states for C storage. When pine regeneration is successful, ~9,200 g C m(-2) accumulate in woodlands but when tree regeneration fails (due to microclimatic stress or short fire return intervals), ecosystem C storage of ~4,000 g C m(-2) will occur in the resulting shrublands.

  2. Soil ecosystem functioning under climate change: plant species and community effects

    Energy Technology Data Exchange (ETDEWEB)

    Kardol, Paul [ORNL; Cregger, Melissa [ORNL; Campany, Courtney E [ORNL; Classen, Aimee T [ORNL

    2010-01-01

    Feedbacks of terrestrial ecosystems to climate change depend on soil ecosystem dynamics. Soil ecosystems can directly and indirectly respond to climate change. For example, warming directly alters microbial communities by increasing their activity. Climate change may also alter plant community composition, thus indirectly altering the microbial communities that feed on their inputs. To better understand how climate change may directly and indirectly alter soil ecosystem functioning, we investigated old-field plant community and soil ecosystem responses to single and combined effects of elevated [CO2], warming, and water availability. Specifically, we collected soils at the plot level (plant community soils), and beneath dominant plant species (plant-specific soils). We used microbial enzyme activities and soil nematodes as indicators for soil ecosystem functioning. Our study resulted in two main findings: 1) Overall, while there were some interactions, water, relative to increases in [CO2] and warming, had the largest impact on plant community composition, soil enzyme activities, and soil nematodes. Multiple climate change factors can interact to shape ecosystems, but in this case, those interactions were largely driven by changes in water availability. 2) Indirect effects of climate change, via changes in plant communities, had a significant impact on soil ecosystem functioning and this impact was not obvious when looking at plant community soils. Climate change effects on enzyme activities and soil nematode abundance and community structure strongly differed between plant community soils and plant-specific soils, but also within plant-specific soils. In sum, these results indicate that accurate assessments of climate change impacts on soil ecosystem functioning require incorporating the concurrent changes in plant function and plant community composition. Climate change-induced shifts in plant community composition will likely modify or counteract the direct

  3. Coexistence via coevolution driven by reduced allelochemical effects and increased tolerance to competition between invasive and native plants.

    Science.gov (United States)

    Huang, Fangfang; Lankau, Richard; Peng, Shaolin

    2018-04-01

    Coevolution can promote long-term coexistence of two competing species if selection acts to reduce the fitness inequality between competitors and/or strengthen negative frequency dependence within each population. However, clear coevolution between plant competitors has been rarely documented. Plant invasions offer opportunities to capture the process of coevolution. Here we investigated how the developing relationship between an invasive forb, Alliaria petiolata, and a native competitor, Pilea pumila, may affect their long-term coexistence, by testing the competitive effects of populations of varying lengths of co-occurrence on each other across a chronosequence of invasion history. Alliaria petiolata and P. pumila tended to develop greater tolerance to competition over invasion history. Their coexistence was promoted more by increases in stabilizing relative to equalizing processes. These changes likely stem in part from reductions in allelopathic traits in the invader and evolution of tolerance in the native. These results suggested that some native species can evolve tolerance against the competitive effects of strong invaders, which likely promoted their persistence in invaded communities. However, the potential for coevolutionary rescue of competing populations is likely to vary across native species, and evolutionary processes should not be expected to compensate for the ecological consequences of exotic invasions. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  4. Plant embryogenesis

    NARCIS (Netherlands)

    Vries, de Sacco C.; Weijers, Dolf

    2017-01-01

    Land plants are called ‘embryophytes’ and thus, their collective name is defined by their ability to form embryos. Indeed, embryogenesis is a widespread phenomenon in plants, and much of our diet is composed of embryos (just think of grains, beans or nuts; Figure 1). However, in addition to embryos

  5. Plant community establishment on the volcanic deposits following the 2006 nuées ardentes (pyroclastic flows of Mount Merapi: diversity and floristic variation

    Directory of Open Access Journals (Sweden)

    SUTOMO

    2011-04-01

    Full Text Available Sutomo, Hobbs R, Cramer V (2011 Plant community establishment on the volcanic deposits following the 2006 nuées ardentes (pyroclastic flows of Mount Merapi: diversity and floristic variation. Biodiversitas 12: 86-91. Species establishment and composition changes in a substrate with little or no biological legacy is known as primary succession, and volcanoes, erosion, landslides, floodplains and glaciers are some type of disturbances that can create this kind of environment. Mount Merapi with its Merapi-type nuées ardentes or pyroclastic flows provides excellent opportunities to study primary succession. Using chronosequence approach, plant establishment and succession was studied, and thus five areas that were affected by nuées ardentes deposits between 1994 and 2006 were chosen as study sites. Results showed that there was a rapid colonization by vascular plants in primary succession as the sites aged. Imperata cylindrica, Eupatorium riparium, Anaphalis javanica, Athyrium macrocarpum, Brachiaria paspaloides, Dichantium caricosum, Selaginella doederleinii, Eleusine indica, Cyperus flavidus, Calliandra callothyrsus and Acacia decurrens were the species mainly responsible in explaining the differences between sites. Furthermore, the species richness and diversity reach their peak 14 years after disturbance.

  6. Plant Macrofossils

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past vegetation and environmental change derived from plant remains large enough to be seen without a microscope (macrofossils), such as leaves, needles,...

  7. T Plant

    Data.gov (United States)

    Federal Laboratory Consortium — Arguably the second most historic building at Hanford is the T Plant.This facility is historic in that it's the oldest remaining nuclear facility in the country that...

  8. Lunar Plants

    Data.gov (United States)

    National Aeronautics and Space Administration — We present an open design for a first plant growth module on the Moon (LPX). The primary science goal of lunar habitat is to investigate germination and initial...

  9. Alien plants

    Science.gov (United States)

    2018-04-01

    No-one’s ever travelled to an extrasolar planet, or even observed one that we’re sure harbours life. But if plants do exist on such alien worlds, we can have fun speculating what form they might take.

  10. Plant simulator

    International Nuclear Information System (INIS)

    Fukumitsu, Hiroyuki

    1998-01-01

    A simulator of a reactor plant of the present invention comprises a plurality of distributed computers, an indication processing section and an operation section. The simulation calculation functions of various kinds of plant models in the plant are shared by the plurality of computers. The indication processing section controls collection of data of the plant simulated by the computers and instructions of an operator. The operation section is operated by the operator and the results of operation are transmitted to the indication processing section, to conduct operation trainings and display the results of the simulation. Each of the computers and the indication processing portion are connected with each other by a network having a memory for common use. Data such as the results of calculation of plant models and various kinds of parameters of the plant required commonly to the calculators and the indication processing section are stored in the common memory, and adapted to be used by way of the network. (N.H.)

  11. Declining plant nitrogen supply and carbon accumulation in ageing primary boreal forest ecosystems

    Science.gov (United States)

    Högberg, Mona N.; Yarwood, Stephanie A.; Trumbore, Susan; Högberg, Peter

    2016-04-01

    Boreal forest soils are commonly characterized by a low plant nitrogen (N) supply. A high tree below-ground allocation of carbon (C) to roots and soil microorganisms in response to the shortage of N may lead to high microbial immobilisation of N, thus aggravating the N limitation. We studied the N supply at a Swedish boreal forest ecosystem chronosequence created by new land rising out of the sea due to iso-static rebound. The youngest soils develop with meadows by the coast, followed by a zone of dinitrogen fixing alder trees, and primary boreal conifer forest on ground up to 560 years old. With increasing ecosystem age, the proportion of microbial C out of the total soil C pool from the youngest to the oldest coniferous ecosystem was constant (c. 1-1.5%), whereas immobilised N (microbial N out of total soil N) increased and approached the levels commonly observed in similar boreal coniferous forests (c. 6-7 %), whereas gross N mineralization declined. Simultaneously, plant foliar N % decreased and the natural abundance of N-15 in the soil increased. More specifically, the difference in N-15 between plant foliage and soil increased, which is related to greater retention of N-15 relative to N-14 by ectomycorrhizal fungi as N is taken up from the soil and some N is transferred to the plant host. In the conifer forest, where these changes were greatest, we found increased fungal biomass in the F- and H-horizons of the mor-layer, in which ectomycorrhizal fungi are known to dominate (the uppermost horizon with litter and moss is dominated by saprotrophic fungi). Hence, we propose that the decreasing N supply to the plants and the subsequent decline in plant production in ageing boreal forests is linked to high tree belowground C allocation to C limited ectomycorrhizal fungi (and other soil microorganisms), a strong sink for available soil N. Data on organic matter C-14 suggested that the largest input of recently fixed plant C occurred in the younger coniferous forest

  12. Mudanças na matéria orgânica do solo causadas pelo tempo de adoção de um sistema agrossilvopastoril com eucalipto Changes in soil organic matter along a chronosequence of an agrosilvipastoral system of eucalypt cultivation

    Directory of Open Access Journals (Sweden)

    Leonardus Vergutz

    2010-02-01

    ções, confirmando sua sensibilidade a alterações de manejo. As perdas de C e N da MOL também foram maiores para a entrelinha de plantio de eucalipto do que para a linha. O C lábil (CL, assim como o índice calculado a partir dele (IMC CL, não possibilitou ajustes dos seus resultados como variável do tempo de implantação dos SASPs. Entretanto, o IMC modificado, calculado a partir do C da MOL (IMC CMOL, apresentou bons ajustes para todas as camadas estudadas; além disso, apresentou correlação mais elevada com o COT, mostrando-se mais indicado para a comparação dos sistemas de manejo estudados. Pôde-se perceber a importância de estudar camadas mais profundas do solo, já que elas podem apresentar perdas de C significativas e de difícil recuperação. A implantação dos SASPs acarretou diminuição dos estoques de COT das camadas superficiais, e o tempo necessário para a recuperação dos estoques originais ficou além do período máximo estudado. A fração mais sensível ao manejo adotado foi a MOL livre.Agrosilvipastoral systems represent agro-forestry practices that allow greater diversity and sustainability of a cropping system. Soil organic matter (SOM is one of the main indicators of the sustainability of a cropping system, especially in tropical soils. The objectives of this study were to investigate the impact of eucalypt cultivation on different C and N of SOM fractions on agrosilvipastoral systems over time. To this end, a chronosequence consisting of six implantation times of an agrosilvipastoral system was sampled. Time zero was represented by the adjacent native vegetation (Cerrado, followed by 2, 3, 4, 7 and 10 year periods since the agrosilvipastoral system implantation in previously Cerrado land. The layers 0-10, 10-20, 20-40, 40-60, and 60-100 cm were sampled in each area, within and in-between eucalypt rows. The samples were chemically and physically analyzed to determine: total organic carbon (TOC, total nitrogen (TN, C in the light organic matter

  13. Plant automation

    International Nuclear Information System (INIS)

    Christensen, L.J.; Sackett, J.I.; Dayal, Y.; Wagner, W.K.

    1989-01-01

    This paper describes work at EBR-II in the development and demonstration of new control equipment and methods and associated schemes for plant prognosis, diagnosis, and automation. The development work has attracted the interest of other national laboratories, universities, and commercial companies. New initiatives include use of new control strategies, expert systems, advanced diagnostics, and operator displays. The unique opportunity offered by EBR-II is as a test bed where a total integrated approach to automatic reactor control can be directly tested under real power plant conditions

  14. Succession Stages of Tundra Plant Communities Following Wildfire Disturbance in Arctic Alaska

    Science.gov (United States)

    Breen, A. L.; Hollingsworth, T. N.; Mack, M. C.; Jones, B. M.

    2015-12-01

    Rapid climate change is affecting climate-sensitive disturbance regimes throughout the world. In particular, the impacts of climate change on Arctic disturbance regimes are poorly understood because landscape-scale disturbances are infrequent or occur in remote localities. Wildfire in Arctic Alaska is presently limited by ignition source and favorable burn weather. With rapid climate change, a lengthening growing season, and subsequent increase in plant biomass and productivity, wildfire frequency and annual area burned in tundra ecosystems is expected to increase over the next century. Yet, post-fire tundra vegetation succession is inadequately characterized except at a few point locations. We identify succession stages of tussock tundra communities following wildfire using a chronosequence of 65 relevés in 10 tundra fire scars (1971-2011) and nearby unburned tundra from sites on the Seward Peninsula and northern foothills of the Brooks Range. We used the Braun-Blanquét approach to classify plant communities, and applied nonmetric multidimentional scaling (NMDS) to identify ecological gradients underlying community differentiation. The ordination revealed a clear differentiation between unburned and burned tundra communities. Ecological gradients, reflected by ordination axes, correspond to fire history (e.g., time since last fire, number of times burned, burn severity) and a complex productivity gradient. Post-fire species richness is less than unburned tundra; primarily reflected as a decrease in lichen species and turnover of bryophyte species immediately post-fire. Species richness of grasses increases post-fire and is greatest in communities that burned more than once in the past 30 years. Shrub cover and total aboveground biomass are greatest in repeat burn sites. We review and discuss our results focusing on the implications of a changing tundra fire regime, its effect on vegetation succession trajectories, and subsequent rates of carbon sequestration and

  15. Plant intelligence

    Science.gov (United States)

    Lipavská, Helena; Žárský, Viktor

    2009-01-01

    The concept of plant intelligence, as proposed by Anthony Trewavas, has raised considerable discussion. However, plant intelligence remains loosely defined; often it is either perceived as practically synonymous to Darwinian fitness, or reduced to a mere decorative metaphor. A more strict view can be taken, emphasizing necessary prerequisites such as memory and learning, which requires clarifying the definition of memory itself. To qualify as memories, traces of past events have to be not only stored, but also actively accessed. We propose a criterion for eliminating false candidates of possible plant intelligence phenomena in this stricter sense: an “intelligent” behavior must involve a component that can be approximated by a plausible algorithmic model involving recourse to stored information about past states of the individual or its environment. Re-evaluation of previously presented examples of plant intelligence shows that only some of them pass our test. “You were hurt?” Kumiko said, looking at the scar. Sally looked down. “Yeah.” “Why didn't you have it removed?” “Sometimes it's good to remember.” “Being hurt?” “Being stupid.”—(W. Gibson: Mona Lisa Overdrive) PMID:19816094

  16. PLANT DIVERSITY

    Science.gov (United States)

    Habitat change statistics and species-area curves were used to estimate the effects of alternative future scenarios for agriculture on plant diversity in Iowa farmlands. Study areas were two watersheds in central Iowa of about 50 and 90 square kilometers, respectively. Future s...

  17. Variable effects of plant colonization on black slate uptake into microbial PLFAs

    Science.gov (United States)

    Seifert, Anne-Gret; Trumbore, Susan; Xu, Xiaomei; Zhang, Dachung; Gleixner, Gerd

    2013-04-01

    Microbial degradation of carbon derived from black shale and slate has been shown in vitro. However, in natural settings where other labile carbon sources are likely to exist, this has not been previously demonstrated. We investigated the uptake of ancient carbon derived from slate weathering and from recently photosynthesised organic matter by different groups of microorganisms. Therefore we isolated microbial biomarkers (phospholipid fatty acids, PLFAs) from black slates collected at a chronosequence of waste piles which differed in age and vegetation cover. We quantified the amount of PLFAs and performed stable isotope and radiocarbon measurements on individual or grouped PLFAs to quantify the fraction of slate derived carbon. We used black slate from a pile heaped in the 1950s with either uncovered black slate material (bare site) or material slightly colonized by small plants (greened site) and from a forested leaching pile (forested site) used for alum-mining in the 19th century. Colonization by plants influenced the amount and composition of the microbial community. Greater amounts of PLFAs (5410 ng PLFA/g dw) were extracted from slate sampled at the forested site as opposed to the bare site (960 ng PLFAs/g dw) or the greened (annual grasses and mosses) rock waste pile (1050 ng PLFAs/g dw). We found the highest proportion of PLFAs representing Gram-negative bacteria on the forested site and the highest proportion of PLFAs representing Gram-positive bacteria on the bare site. The fungal PLFA was most abundant at the greened site. Sites with less plant colonization (bare and greened site) tended to have more depleted δ13C values compared to the forested site. Radiocarbon measurements on PLFAs indicated that fungi and Gram-positive bacteria were best adapted to black slate carbon uptake. In the fungal PLFA (combined bare and greened waste pile sample) and in PLFAs of Gram-positive bacteria (greened site) we measured 39.7% and 28.9% ancient carbon uptake

  18. Stress tolerant plants

    OpenAIRE

    Rubio, Vicente; Iniesto Sánchez, Elisa; Irigoyen Miguel, María Luisa

    2014-01-01

    [EN] The invention relates to transgenic plants and methods for modulating abscisic acid (ABA) perception and signal transduction in plants. The plants find use in increasing yield in plants, particularly under abiotic stress.

  19. Insect herbivores change the outcome of plant competition through both inter- and intraspecific processes.

    Science.gov (United States)

    Kim, Tania N; Underwood, Nora; Inouye, Brian D

    2013-08-01

    Insect herbivores can affect plant abundance and community composition, and theory suggests that herbivores influence plant communities by altering interspecific interactions among plants. Because the outcome of interspecific interactions is influenced by the per capita competitive ability of plants, density dependence, and intrinsic rates of increase, measuring herbivore effects on all these processes is necessary to understand the mechanisms by which herbivores influence plant communities. We fit alternative competition models to data from a response surface experiment conducted over four years to examine how herbivores affected the outcome of competition between two perennial plants, Solidago altissima and Solanum carolinense. Within a growing season, herbivores reduced S. carolinense plant size but did not affect the size of S. altissima, which exhibited compensatory growth. Across seasons, herbivores did not affect S. carolinense density or biomass but reduced both the density and population growth of S. altissima. The best-fit models indicated that the effects of herbivores varied with year. In some years, herbivores increased the per capita competitive effect of S. altissima on S. carolinense; in other years, herbivores influenced the intrinsic rate of increase of S. altissima. We examined possible herbivore effects on the longer-term outcome of competition (over the time scale of a typical old-field habitat), using simulations based on the best-fit models. In the absence of herbivores, plant coexistence was observed. In the presence of herbivores, S. carolinense was excluded by S. altissima in 72.3% of the simulations. We demonstrate that herbivores can influence the outcome of competition through changes in both per capita competitive effects and intrinsic rates of increase. We discuss the implications of these results for ecological succession and biocontrol.

  20. Plant Host Finding by Parasitic Plants: A New Perspective on Plant to Plant Communication

    OpenAIRE

    Mescher, Mark C; Runyon, Justin B; De Moraes, Consuelo M

    2006-01-01

    Plants release airborne chemicals that can convey ecologically relevant information to other organisms. These plant volatiles are known to mediate a large array of, often complex, interactions between plants and insects. It has been suggested that plant volatiles may have similar importance in mediating interactions among plant species, but there are few well-documented examples of plant-to-plant communication via volatiles, and the ecological significance of such interactions has been much d...

  1. Nuclear power plants

    International Nuclear Information System (INIS)

    1985-01-01

    Data concerning the existing nuclear power plants in the world are presented. The data was retrieved from the SIEN (Nuclear and Energetic Information System) data bank. The information are organized in table forms as follows: nuclear plants, its status and type; installed nuclear power plants by country; nuclear power plants under construction by country; planned nuclear power plants by country; cancelled nuclear power plants by country; shut-down nuclear power plants by country. (E.G.) [pt

  2. LNG plant combined with power plant

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, I; Kikkawa, Y [Chiyoda Chemical Engineering and Construction Co. Ltd., Tokyo (Japan)

    1997-06-01

    The LNG plant consumers a lot of power of natural gas cooling and liquefaction. In some LNG plant location, a rapid growth of electric power demand is expected due to the modernization of area and/or the country. The electric power demand will have a peak in day time and low consumption in night time, while the power demand of the LNG plant is almost constant due to its nature. Combining the LNG plant with power plant will contribute an improvement the thermal efficiency of the power plant by keeping higher average load of the power plant, which will lead to a reduction of electrical power generation cost. The sweet fuel gas to the power plant can be extracted from the LNG plant, which will be favorable from view point of clean air of the area. (Author). 5 figs.

  3. LNG plant combined with power plant

    International Nuclear Information System (INIS)

    Aoki, I.; Kikkawa, Y.

    1997-01-01

    The LNG plant consumers a lot of power of natural gas cooling and liquefaction. In some LNG plant location, a rapid growth of electric power demand is expected due to the modernization of area and/or the country. The electric power demand will have a peak in day time and low consumption in night time, while the power demand of the LNG plant is almost constant due to its nature. Combining the LNG plant with power plant will contribute an improvement the thermal efficiency of the power plant by keeping higher average load of the power plant, which will lead to a reduction of electrical power generation cost. The sweet fuel gas to the power plant can be extracted from the LNG plant, which will be favorable from view point of clean air of the area. (Author). 5 figs

  4. Plant host finding by parasitic plants: a new perspective on plant to plant communication.

    Science.gov (United States)

    Mescher, Mark C; Runyon, Justin B; De Moraes, Consuelo M

    2006-11-01

    Plants release airborne chemicals that can convey ecologically relevant information to other organisms. These plant volatiles are known to mediate a large array of, often complex, interactions between plants and insects. It has been suggested that plant volatiles may have similar importance in mediating interactions among plant species, but there are few well-documented examples of plant-to-plant communication via volatiles, and the ecological significance of such interactions has been much debated. To date, nearly all studies of volatile-mediated interactions among plant species have focused on the reception of herbivore-induced volatiles by neighboring plants. We recently documented volatile effects in another system, demonstrating that the parasitic plant Cuscuta pentagona uses volatile cues to locate its hosts. This finding may broaden the discussion regarding plant-to-plant communication, and suggests that new classes of volatile-meditated interactions among plant species await discovery.

  5. Floristic composition and plant succession on near-surface radioactive-waste-disposal facilities in the Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Tierney, G.D.; Foxx, T.S.

    1982-03-01

    Since 1946, low-level radioactive waste has been buried in shallow landfills within the confines of the Los Alamos National Laboratory. Five of these sites were studied for plant composition and successional patterns by reconnaissance and vegetation mapping. The data show a slow rate of recovery for all sites, regardless of age, in both the pinon-juniper and ponderosa pine communities. The sites are not comparable in succession or composition because of location and previous land use. The two oldest sites have the highest species diversity and the only mature trees. All sites allowed to revegetate naturally tend to be colonized by the same species that originally surrounded the sites. Sites on historic fields are colonized by the old field flora, whereas those in areas disturbed only by grazing are revegetated by the local native flora

  6. Floristic composition and plant succession on near-surface radioactive-waste-disposal facilities in the Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Tierney, G.D.; Foxx, T.S.

    1982-03-01

    Since 1946, low-level radioactive waste has been buried in shallow landfills within the confines of the Los Alamos National Laboratory. Five of these sites were studied for plant composition and successional patterns by reconnaissance and vegetation mapping. The data show a slow rate of recovery for all sites, regardless of age, in both the pinon-juniper and ponderosa pine communities. The sites are not comparable in succession or composition because of location and previous land use. The two oldest sites have the highest species diversity and the only mature trees. All sites allowed to revegetate naturally tend to be colonized by the same species that originally surrounded the sites. Sites on historic fields are colonized by the old field flora, whereas those in areas disturbed only by grazing are revegetated by the local native flora.

  7. Plant host finding by parasitic plants: A new perspective on plant to plant communication

    Science.gov (United States)

    Mark C. Mescher; Justin B. Runyon; Consuelo M. De Moraes

    2006-01-01

    Plants release airborne chemicals that can convey ecologically relevant information to other organisms. These plant volatiles are known to mediate a large array of, often complex, interactions between plants and insects. It has been suggested that plant volatiles may have similar importance in mediating interactions among plant species, but there are few well-...

  8. Kansas Power Plants

    Data.gov (United States)

    Kansas Data Access and Support Center — The Kansas Power Plants database depicts, as point features, the locations of the various types of power plant locations in Kansas. The locations of the power plants...

  9. Gender in Plants

    Indian Academy of Sciences (India)

    What is the difference between plant sex and plant gender? Why does stress .... environmental sex determination is often predictable. Sunlit patches favour .... ensures that these self-incompatible plants receive cross-pollen only. i emporal ...

  10. Engineered Plants as Biosensors

    National Research Council Canada - National Science Library

    Stewart, C

    2003-01-01

    The aim of the research was the creation of a model biosensing plant that could detect plant diseases and to characterize the utility of laser induced fluorescence imaging for detecting the inducible (LIFI) plant signal...

  11. Plant stress signalling: understanding and exploiting plant-plant interactions.

    Science.gov (United States)

    Pickett, J A; Rasmussen, H B; Woodcock, C M; Matthes, M; Napier, J A

    2003-02-01

    When plants are attacked by insects, volatile chemical signals can be released, not only from the damaged parts, but also systemically from other parts of the plant and this continues after cessation of feeding by the insect. These signals are perceived by olfactory sensory mechanisms in both the herbivorous insects and their parasites. Molecular structures involved can be characterized by means of electrophysiological assays, using the insect sensory system linked to chemical analysis. Evidence is mounting that such signals can also affect neighbouring intact plants, which initiate defence by the induction of further signalling systems, such as those that increase parasitoid foraging. Furthermore, insect electrophysiology can be used in the identification of plant compounds having effects on the plants themselves. It has been found recently that certain plants can release stress signals even when undamaged, and that these can cause defence responses in intact plants. These discoveries provide the basis for new crop protection strategies, that are either delivered by genetic modification of plants or by conventionally produced plants to which the signal is externally applied. Delivery can also be made by means of mixed seed strategies in which the provoking and recipient plants are grown together. Related signalling discoveries within the rhizosphere seem set to extend these approaches into new ways of controlling weeds, by exploiting the elusive potential of allelopathy, but through signalling rather than by direct physiological effects.

  12. Patterns of tree species diversity and composition in old-field successional forests in central Illinois

    Science.gov (United States)

    Scott M. Bretthauer; George Z. Gertner; Gary L. Rolfe; Jeffery O. Dawson

    2003-01-01

    Tree species diversity increases and dominance decreases with proximity to forest border in two 60-year-old successional forest stands developed on abandoned agricultural land in Piatt County, Illinois. A regression equation allowed us to quantify an increase in diversity with closeness to forest border for one of the forest stands. Shingle oak is the most dominant...

  13. Soil Structure and Mycorrhizae Encourage Black Walnut Growth on Old Fields

    Science.gov (United States)

    Felix Jr. Ponder

    1979-01-01

    Examination of black walnut seedlings grown in forest and field soils showed all root systems were infected with mycorrhizae; the amount of infection was influenced by treatments. Mean height and dry weight of tops and roots were greater for seedlings grown in forest than field soil. Seedling height growth was not increased by disturbing either soil; but, root dry...

  14. Actin complexes in the cell nucleus: new stones in an old field

    Czech Academy of Sciences Publication Activity Database

    Castano, Enrique; Philimonenko, Vlada; Kahle, Michal; Fukalová, Jana; Kalendová, Alžběta; Yildirim, Sukriye; Dzijak, Rastislav; Dingová, Hana; Hozák, Pavel

    2010-01-01

    Roč. 133, č. 6 (2010), s. 607-626 ISSN 0948-6143 R&D Projects: GA ČR(CZ) GA204/07/1592; GA ČR(CZ) GD204/09/H084; GA MŠk LC545; GA MŠk 2B06063 Institutional research plan: CEZ:AV0Z50520514 Keywords : RNA polymerase II * ABL tyrosine kinase * F-actin Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.727, year: 2010

  15. Plants get sick too!

    Science.gov (United States)

    Although many people may never have given consideration to plant health, plants can suffer from a wide range of diseases. These plant diseases are caused by micro-organisms, including bacteria, fungi, and viruses. The audience will be introduced to short case studies of several plant diseases that m...

  16. Plant extraction process

    DEFF Research Database (Denmark)

    2006-01-01

    A method for producing a plant extract comprises incubating a plant material with an enzyme composition comprising a lipolytic enzyme.......A method for producing a plant extract comprises incubating a plant material with an enzyme composition comprising a lipolytic enzyme....

  17. Radioactive uptake by plants

    Energy Technology Data Exchange (ETDEWEB)

    Horak, O

    1986-01-01

    The fundamentals of radionuclide uptake by plants, both by leaves and roots are presented. Iodine, cesium, strontium and ruthenium are considered and a table of the measured concentrations in several agricultural plants shortly after the Chernobyl accident is presented. Another table gives the Cs and Sr transfer factors soil plants for some plants. By using them estimates of future burden can be obtained.

  18. Plant Biology Science Projects.

    Science.gov (United States)

    Hershey, David R.

    This book contains science projects about seed plants that deal with plant physiology, plant ecology, and plant agriculture. Each of the projects includes a step-by-step experiment followed by suggestions for further investigations. Chapters include: (1) "Bean Seed Imbibition"; (2) "Germination Percentages of Different Types of Seeds"; (3)…

  19. Plants' essential chemical elements

    Science.gov (United States)

    Kevin T. Smith

    2007-01-01

    Every garden center and hardware store sells fertilizer guaranteed to "feed" plants. In a strict sense, we can't feed plants. Food contains an energy source. Green plants capture solar energy and make their own food through photosynthesis! Photosynthesis and other metabolic processes require chemical elements in appropriate doses for plants to survive...

  20. Changes in tree species richness, stand structure and soil properties in a successional chronosequence in northern Chiloé Island, Chile Cambios en la riqueza de especies arbóreas, estructura de rodales y propiedades del suelo en una cronosecuencia sucesional en el norte de la Isla de Chiloé, Chile

    Directory of Open Access Journals (Sweden)

    JUAN C. ARAVENA

    2002-06-01

    Full Text Available We studied a chronosequence of forest fragments in northern Chiloé Island, southern Chile, with the aim of assessing ecosystem recovery patterns following anthropogenic disturbance. Hypotheses regarding successional trends in tree species richness, the replacement of shade-intolerant by shade-tolerant species, and the impact of disturbance on soil properties were evaluated in nine forest stands. The chronosequence encompassed two early (minimum stand age Estudiamos una cronosecuencia de bosques sucesionales en el norte de la Isla de Chiloé, con el objeto de determinar sus patrones de recuperación luego de perturbación antrópica. Se evaluaron hipótesis referentes a las tendencias de cambio en la riqueza de especies arbóreas a lo largo de la sucesión, el reemplazo de especies sombra intolerantes por especies sombra tolerantes, y el impacto de la perturbación en las propiedades edáficas de estos fragmentos. Muestreamos nueve rodales, representados por dos bosques sucesionales tempranos (<15 años de edad mínima del rodal, tres rodales intermedios (30-60 años, tres avanzados (129-134 años, y un bosque antiguo (ca. 200 años. Las edades mínimas fueron estimadas a través de muestras de incremento radial de al menos 30 árboles del dosel por rodal. Los rodales tempranos e intermedios mostraron evidencias de perturbación por incendios moderados, con unos pocos grandes árboles vivos remanentes. En cada rodal se establecieron parcelas permanentes de 50 x 20 m para determinar densidades y áreas basales de árboles, con subparcelas interiores para estimar densidades de brinzales y plántulas. Para caracterizar los procesos edáficos en los rodales se determinó el pH del suelo, los contenidos totales de carbono (C y nitrógeno (N, N disponible y densidad aparente. En contraste con la hipótesis que predice una disminución de la riqueza de especies arbóreas en rodales más antiguos, debido a la exclusión de especies pioneras, la riqueza

  1. Plant Research '75

    Energy Technology Data Exchange (ETDEWEB)

    1975-01-01

    Research is reported on stomatal regulation of the gas exchanges between plant and environment; inhibitory effects in flower formation; plant growth and development through hormones; hormone action; development and nitrogen fixation in algae; primary cell wall glycoprotein ectensin; enzymic mechanisms and control of polysaccharide and glycoprotein synthesis; molecular studies of membrane studies; sensory transduction in plants; regulation of formation of protein complexes and enzymes in higher plant cell and mechanism of sulfur dioxide toxicity in plants. (PCS)

  2. PLANT BIOPRINTING: NOVEL PERSPECTIVE FOR PLANT BIOTECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Adhityo WICAKSONO

    2015-12-01

    Full Text Available Bioprinting is a technical innovation that has revolutionized tissue engineering. Using conventional printer cartridges filled with cells as well as a suitable scaffold, major advances have been made in the biomedical field, and it is now possible to print skin, bones, blood vessels, and even organs. Unlike animal systems, the application of bioprinting in simple plant tissue cells is still in a nascent phase and has yet to be studied. One major advantage of plants is that all living parts are reprogrammable in the form of totipotent cells. Plant bioprinting may improve scientists’understanding of plant shape and morphogenesis, and could serve for the mass production of desired tissues or plants, or even the production of plant-based biomaterial for industrial uses. This perspectives paper explores these possibilities using knowledge on what is known about bioprinting in other biosystems.

  3. An assessment of a community-based, forest restoration programme in Durban (eThekwini), South Africa

    CSIR Research Space (South Africa)

    Mugwedi, LF

    2017-07-01

    Full Text Available Site Community Reforestation Project in Durban, South Africa, by assessing ecological attributes. Measures of plant richness, diversity, vegetation structure, invasive alien plants (IAPs) and ecological processes were contrasted across a chronosequence...

  4. 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

  5. Biochar potential in intensive cultivation of Capsicum annuum L. (sweet pepper): crop yield and plant protection.

    Science.gov (United States)

    Kumar, Abhay; Elad, Yigal; Tsechansky, Ludmila; Abrol, Vikas; Lew, Beni; Offenbach, Rivka; Graber, Ellen R

    2018-01-01

    The influence of various biochars on crop yield and disease resistance of Capsicum annuum L. (sweet pepper) under modern, high input, intensive net house cultivation was tested over the course of 2011-2014 in the Arava desert region of Israel. A pot experiment with Lactuca sativa L. (lettuce) grown in the absence of fertilizer employed the 3-year-old field trial soils to determine if biochar treatments contributed to soil intrinsic fertility. Biochar amendments resulted in a significant increase in the number and weight of pepper fruits over 3 years. Concomitant with the increased yield, biochar significantly decreased the severity of powdery mildew (Leveillula taurica) disease and broad mite (Polyphagotarsonemus latus) pest infestation. Biochar additions resulted in increased soil organic matter but did not influence the pH, electrical conductivity or soil or plant mineral nutrients. Intrinsic fertility experiments with lettuce showed that two of the four biochar-treated field soils had significant positive impacts on lettuce fresh weight and total chlorophyll, carotenoid and anthocyanin contents. Biochar-based soil management can enhance the functioning of intensive, commercial, net house production of peppers under the tested conditions, resulting in increased crop yield and plant resistance to disease over several years. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  6. Phosphorus cycling in natural and low input soil/plant systems: the role of soil microorganisms

    Science.gov (United States)

    Tamburini, F.; Bünemann, E. K.; Oberson, A.; Bernasconi, S. M.; Frossard, E.

    2011-12-01

    Availability of phosphorus (as orthophosphate, Pi) limits biological production in many terrestrial ecosystems. During the first phase of soil development, weathering of minerals and leaching of Pi are the processes controlling Pi concentrations in the soil solution, while in mature soils, Pi is made available by desorption of mineral Pi and mineralization of organic compounds. In agricultural soils additional Pi is supplied by fertilization, either with mineral P and/or organic inputs (animal manure or plant residues). Soil microorganisms (bacteria and fungi) mediate several processes, which are central to the availability of Pi to plants. They play a role in the initial release of Pi from the mineral phase, and through extracellular phosphatase enzymes, they decompose and mineralize organic compounds, releasing Pi. On the other hand, microbial immobilization and internal turnover of Pi can decrease the soil available Pi pool, competing in this way with plants. Using radio- and stable isotopic approaches, we show evidence from different soil/plant systems which points to the central role of the microbial activity. In the presented case studies, P contained in the soil microbial biomass is a larger pool than available Pi. In a soil chronosequence after deglaciation, stable isotopes of oxygen associated to phosphate showed that even in the youngest soils microbial activity highly impacted the isotopic signature of available Pi. These results suggested that microorganisms were rapidly taking up and cycling Pi, using it to sustain their community. Microbial P turnover time was faster in the young (about 20 days) than in older soils (about 120 days), reflecting a different functioning of the microbial community. Microbial community crashes, caused by drying/rewetting and freezing/thawing cycles, were most likely responsible for microbial P release to the available P pool. In grassland fertilization experiments with mineral NK and NPK amendments, microbial P turnover

  7. Plutonium Plant, Trombay

    International Nuclear Information System (INIS)

    Yadav, J.S.; Agarwal, K.

    2017-01-01

    The journey of Indian nuclear fuel reprocessing started with the commissioning of Plutonium Plant (PP) at Trombay on 22"n"d January, 1965 with an aim to reprocess the spent fuel from research reactor CIRUS. The basic process chosen for the plant was Plutonium Uranium Reduction EXtraction (PUREX) process. In seventies, the plant was subjected to major design modifications and replacement of hardware, which later met the additional demand from research reactor DHRUVA. The augmented plutonium plant has been operating since 1983. Experience gained from this plant was very much helpful to design future reprocessing plant in the country

  8. Better plants through mutations

    International Nuclear Information System (INIS)

    1988-01-01

    This is a public relations film describing problems associated with the genetic improvement of crop plants through induced mutations. Mutations are the ultimate source of genetic variation in plants. Mutation induction is now established as a practical tool in plant breeding. The Joint FAO/IAEA Division and the IAEA's laboratory at Seibersdorf have supported research and practical implementation of mutation breeding of both seed propagated and vegetatively propagated plants. Plant biotechnology based on in vitro culture and recombinant DNA technology will make a further significant contribution to plant breeding

  9. Plant Phenotype Characterization System

    Energy Technology Data Exchange (ETDEWEB)

    Daniel W McDonald; Ronald B Michaels

    2005-09-09

    This report is the final scientific report for the DOE Inventions and Innovations Project: Plant Phenotype Characterization System, DE-FG36-04GO14334. The period of performance was September 30, 2004 through July 15, 2005. The project objective is to demonstrate the viability of a new scientific instrument concept for the study of plant root systems. The root systems of plants are thought to be important in plant yield and thus important to DOE goals in renewable energy sources. The scientific study and understanding of plant root systems is hampered by the difficulty in observing root activity and the inadequacy of existing root study instrumentation options. We have demonstrated a high throughput, non-invasive, high resolution technique for visualizing plant root systems in-situ. Our approach is based upon low-energy x-ray radiography and the use of containers and substrates (artificial soil) which are virtually transparent to x-rays. The system allows us to germinate and grow plant specimens in our containers and substrates and to generate x-ray images of the developing root system over time. The same plant can be imaged at different times in its development. The system can be used for root studies in plant physiology, plant morphology, plant breeding, plant functional genomics and plant genotype screening.

  10. Plant tissue culture techniques

    Directory of Open Access Journals (Sweden)

    Rolf Dieter Illg

    1991-01-01

    Full Text Available Plant cell and tissue culture in a simple fashion refers to techniques which utilize either single plant cells, groups of unorganized cells (callus or organized tissues or organs put in culture, under controlled sterile conditions.

  11. Plant Tissue Culture

    Indian Academy of Sciences (India)

    Admin

    Plant tissue culture is a technique of culturing plant cells, tissues and organs on ... working methods (Box 2) and discovery of the need for B vita- mins and auxins for ... Kotte (Germany) reported some success with growing isolated root tips.

  12. Fertilization in Flowering Plants

    Indian Academy of Sciences (India)

    IAS Admin

    Ecology and the Environ- ment, Bengaluru as ... remaining plants, it is an abiotic agent (abiotic pollination), .... tion was slow until the origin of flowering plants and evolution of ..... Although pollination is generally a mutual interaction in a major-.

  13. Plant proton pumps

    DEFF Research Database (Denmark)

    Gaxiola, Roberto A.; Palmgren, Michael Gjedde; Schumacher, Karin

    2007-01-01

    Chemiosmotic circuits of plant cells are driven by proton (H+) gradients that mediate secondary active transport of compounds across plasma and endosomal membranes. Furthermore, regulation of endosomal acidification is critical for endocytic and secretory pathways. For plants to react...

  14. Terrestrial plant methane production

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Bruhn, Dan; Møller, Ian M.

    We evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants. We conclude that the phenomenon is true. Four stimulating factors have been observed to induce aerobic plant CH4 production, i.e. cutting injuries, increasing temperature...... the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH4 precursors in plant material....

  15. Plant aquaporins: roles in plant physiology.

    Science.gov (United States)

    Li, Guowei; Santoni, Véronique; Maurel, Christophe

    2014-05-01

    Aquaporins are membrane channels that facilitate the transport of water and small neutral molecules across biological membranes of most living organisms. Here, we present comprehensive insights made on plant aquaporins in recent years, pointing to their molecular and physiological specificities with respect to animal or microbial counterparts. In plants, aquaporins occur as multiple isoforms reflecting a high diversity of cellular localizations and various physiological substrates in addition to water. Of particular relevance for plants is the transport by aquaporins of dissolved gases such as carbon dioxide or metalloids such as boric or silicic acid. The mechanisms that determine the gating and subcellular localization of plant aquaporins are extensively studied. They allow aquaporin regulation in response to multiple environmental and hormonal stimuli. Thus, aquaporins play key roles in hydraulic regulation and nutrient transport in roots and leaves. They contribute to several plant growth and developmental processes such as seed germination or emergence of lateral roots. Plants with genetically altered aquaporin functions are now tested for their ability to improve plant resistance to stresses. This article is part of a Special Issue entitled Aquaporins. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Plants under dual attack

    NARCIS (Netherlands)

    Ponzio, C.A.M.

    2016-01-01

    Though immobile, plants are members of complex environments, and are under constant threat from a wide range of attackers, which includes organisms such as insect herbivores or plant pathogens. Plants have developed sophisticated defenses against these attackers, and include chemical responses

  17. Growing Plants and Minds

    Science.gov (United States)

    Presser, Ashley Lewis; Kamdar, Danae; Vidiksis, Regan; Goldstein, Marion; Dominguez, Ximena; Orr, Jillian

    2017-01-01

    Many preschool classrooms explore plant growth. However, because many plants take a long time to grow, it is often hard to facilitate engagement in some practices (i.e., since change is typically not observable from one day to another, children often forget their prior predictions or cannot recall what plants looked like days or weeks earlier).…

  18. Fundaments of plant cybernetics.

    Science.gov (United States)

    Zucconi, F

    2001-01-01

    A systemic approach is proposed for analyzing plants' physiological organization and cybernesis. To this end, the plant is inspected as a system, starting from the integration of crown and root systems, and its impact on a number of basic epigenetic events. The approach proves to be axiomatic and facilitates the definition of the principles behind the plant's autonomous control of growth and reproduction.

  19. Plant or Animal?

    Science.gov (United States)

    Bowman, Frank; Matthews, Catherine E.

    1996-01-01

    Presents activities that use marine organisms with plant-like appearances to help students build classification skills and illustrate some of the less obvious differences between plants and animals. Compares mechanisms by which sessile plants and animals deal with common problems such as obtaining energy, defending themselves, successfully…

  20. Small hydroelectric power plants

    International Nuclear Information System (INIS)

    Helgesen, Boerre

    2002-01-01

    Small hydroelectric power plants are power plants of 1 - 10 MW. For a supplier, this is an unnatural limit. A more natural limit involves compact engine design and simplified control system. The article discusses most of the engine and electrotechnical aspects in the development, construction and operation of such a plant

  1. Recognizing Plant Defense Priming.

    Science.gov (United States)

    Martinez-Medina, Ainhoa; Flors, Victor; Heil, Martin; Mauch-Mani, Brigitte; Pieterse, Corné M J; Pozo, Maria J; Ton, Jurriaan; van Dam, Nicole M; Conrath, Uwe

    2016-10-01

    Defense priming conditions diverse plant species for the superinduction of defense, often resulting in enhanced pest and disease resistance and abiotic stress tolerance. Here, we propose a guideline that might assist the plant research community in a consistent assessment of defense priming in plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Plant Physiology in Greenhouses

    NARCIS (Netherlands)

    Heuvelink, E.; Kierkels, T.

    2015-01-01

    Since 2004 Ep Heuvelink and Tijs Kierkels have been writing a continuing series of plant physiology articles for the Dutch horticultural journal Onder Glas and the international edition In Greenhouses. The book Plant Physiology in Greenhouses consists of 50 of their plant physiology articles. The

  3. Plants and people

    Science.gov (United States)

    Kathryn Lynch

    2012-01-01

    Salal! Salmonberries! Sword ferns! The Northwest is home to a great number of native plant species that humans have used for centuries. Sadly, many local children are unaware of the history and culture connecting people and plants. Yet, from the beginning of time, plants have provided us food, medicine, and material for clothing, shelter, transportation, decoration,...

  4. Plant Systems Biology (editorial)

    Science.gov (United States)

    In June 2003, Plant Physiology published an Arabidopsis special issue devoted to plant systems biology. The intention of Natasha Raikhel and Gloria Coruzzi, the two editors of this first-of-its-kind issue, was ‘‘to help nucleate this new effort within the plant community’’ as they considered that ‘‘...

  5. Plants of the Bayshore.

    Science.gov (United States)

    Bachle, Leo; And Others

    This field guide gives pictures and descriptions of plants that can be found along the San Francisco Bayshore, especially along the Hayward shoreline. The plants are divided into three categories, those of the mud-flat zone, the drier zone, and the levee zone. Eighteen plants are represented in all. The guide is designed to be used alone, with an…

  6. TRANSGENIC PLANT CONTAINMENT

    Science.gov (United States)

    The new technology using plant genetics to produce chemicals, pharmaceuticals, and therapeuitics in a wide array of new plant forms requires sufficient testing to ensure that these new plant introductions are benign in the environment. A recent effort to provide necessary guidan...

  7. Plant Breeding Goes Microbial

    NARCIS (Netherlands)

    Wei, Zhong; Jousset, Alexandre

    Plant breeding has traditionally improved traits encoded in the plant genome. Here we propose an alternative framework reaching novel phenotypes by modifying together genomic information and plant-associated microbiota. This concept is made possible by a novel technology that enables the

  8. Plant innate immunity

    Indian Academy of Sciences (India)

    Plants are invaded by an array of pathogens of which only a few succeed in causing disease. The attack by others is countered by a sophisticated immune system possessed by the plants. The plant immune system is broadly divided into two, viz. microbial-associated molecular-patterns-triggered immunity (MTI) and ...

  9. Diagnosing plant problems

    Science.gov (United States)

    Cheryl A. Smith

    2008-01-01

    Diagnosing Christmas tree problems can be a challenge, requiring a basic knowledge of plant culture and physiology, the effect of environmental influences on plant health, and the ability to identify the possible causes of plant problems. Developing a solution or remedy to the problem depends on a proper diagnosis, a process that requires recognition of a problem and...

  10. Decoupling of soil development and plant succession along a 60000 years chronosequence in Llaima Volcano, Chile Desacoplamiento del desarrollo del suelo y la sucesión vegetal a lo largo de una cronosecuencia de 60 mil años en el volcán Llaima, Chile

    OpenAIRE

    MARÍA-BELÉN GALLARDO; CECILIA PÉREZ; MARIELA NÚÑEZ-ÁVILA; JUAN J. ARMESTO

    2012-01-01

    Few studies have investigated the long-term evolution of nutrient limitation in ecosystems developed on volcanic soils. To approach the problem, we used "space for time substitution" to compare sites with the same state factors, except for the time elapsed since disturbance. Forests of Conguillio National Park in southern of Chile occur on volcanic soils that developed from lava flows and ash deposits of different ages originated from the activity of Llaima volcano. In this study we evaluate ...

  11. Hydroelectric Power Plants Dobsina

    International Nuclear Information System (INIS)

    Majercak, V.; Srenkelova, Z.; Kristak, J.G.

    1997-01-01

    In this brochure the Hydroelectric Power Plants Dobsina, (VED), subsidiary of the utility Slovenske Elektrarne, a.s. (Slovak Electric, plc. Bratislava) are presented. VED is mainly aimed at generating peak-load electrical energy and maintenance of operational equipment. Reaching its goals, company is first of all focused on reliability of production, economy and effectiveness, keeping principles of work safety and industry safety standards and also ecology. VED operates eight hydroelectric power plants, from which PVE Ruzin I and PVE Dobsina I are pump storage ones and they are controlled directly by the Slovak Energy Dispatch Centre located in Zilina thought the system LS 3200. Those power plants participate in secondary regulation of electrical network of Slovakia. They are used to compensate balance in reference to foreign electrical networks and they are put into operation independently from VED. Activity of the branch is focused mainly on support of fulfilment of such an important aim as electric network regulation. Beginnings of the subsidiary Hydroelectric Power Plants Dobsina are related to the year of 1948. After commissioning of the pump storage Hydroelectric Power Plants Dobsina in 1953, the plant started to carry out its mission. Since that time the subsidiary has been enlarged by other seven power plants, through which it is fulfilling its missions nowadays. The characteristics of these hydroelectric power plants (The pump-storage power plant Dobsina, Small hydroelectric power plant Dobsina II, Small hydroelectric power plant Rakovec, Small hydroelectric power plant Svedlar, Hydroelectric power plant Domasa, The pump-storage power plant Ruzin, and Small hydroelectric power plant Krompachy) are described in detail. Employees welfare and public relations are presented

  12. Litter decomposition along a primary post-mining chronosequence

    Czech Academy of Sciences Publication Activity Database

    Urbanová, Michaela; Šnajdr, Jaroslav; Brabcová, Vendula; Merhautová, Věra; Dobiášová, Petra; Cajthaml, Tomáš; Vaněk, D.; Frouz, J.; Šantrůčková, H.; Baldrian, Petr

    2014-01-01

    Roč. 50, č. 5 (2014), s. 827-837 ISSN 0178-2762 R&D Projects: GA MŠk LC06066; GA ČR GAP504/12/1288 Institutional support: RVO:61388971 Keywords : microbial community * composition * soil * quercus * mining area Subject RIV: EE - Microbiology, Virology Impact factor: 3.398, year: 2014

  13. Mineralogy and pedogenesis in a soil chronosequence on a ...

    African Journals Online (AJOL)

    Studies on soils of the floodplain of lower Niger river are scanty although this floodplain forms a very important agricultural resource base in Nigeria. The objective of this study is to provide comprehensive information on the characteristics of the soils with respect to their mineralogy and the effect of seasonal flooding on their ...

  14. Multinationals and plant survival

    DEFF Research Database (Denmark)

    Bandick, Roger

    2010-01-01

    The aim of this paper is twofold: first, to investigate how different ownership structures affect plant survival, and second, to analyze how the presence of foreign multinational enterprises (MNEs) affects domestic plants’ survival. Using a unique and detailed data set on the Swedish manufacturing...... sector, I am able to separate plants into those owned by foreign MNEs, domestic MNEs, exporting non-MNEs, and purely domestic firms. In line with previous findings, the result, when conditioned on other factors affecting survival, shows that foreign MNE plants have lower survival rates than non......-MNE plants. However, separating the non-MNEs into exporters and non-exporters, the result shows that foreign MNE plants have higher survival rates than non-exporting non-MNEs, while the survival rates of foreign MNE plants and exporting non-MNE plants do not seem to differ. Moreover, the simple non...

  15. Plant life management

    International Nuclear Information System (INIS)

    Charbonneau, S.; Framatome, J.B.

    1992-01-01

    Plant life assessment and extension studies have been performed by numerous companies all over the world. Critical equipment has been identified as well as various degradation mechanisms involved in the plant aging process. Nowadays one has to think what to implement to improve the existing situation in the Nuclear Power Plant (NPP). FRAMATOME has undertaken this thought process in order to find the right answers and bring them to utilities facing either critical concern for plant life extension or the problem of management of power plant potential longevity. This is why we prepared a Plant Life Improvement Action Plan, comprising 10 (ten) major items described hereafter using examples of work performed by FRAMATOME for its utility customers desiring to manage the lives of their plants, both in France with EDF and abroad

  16. Photochemical smog and plants

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, T.

    1974-07-01

    Surveys of plant damage due to photochemical smog are summarized. The components of smog which appear to be responsible for plant damage include ozone and peroxyacyl nitrates. Their phytotoxic effects are much greater than those due to sulfur oxides. Damage surveys since 1970 reveal the following symptoms appearing on herbaceous plants (morning glory, cocks comb, dahlia, knotweed, petunia, chickweed, Welsh onion, spinach, Chinese cabbage, chard, taro): yellowish-white leaf discoloration, white and brown spots on matured leaves, and silvering of the lower surfaces of young leaves. Symptoms which appear on arboraceous plants such as zelkova, poplar, ginkgo, planetree, rose mallow, magnolia, pine tree, and rhododendron include early yellowing and reddening, white or brown spots, and untimely leaf-fall. The above plants are now utilized as indicator plants of photochemical smog. Surveys covering a broad area of Tokyo and three other prefectures indicate that plant damage due to photochemical smog extends to relatively unpolluted areas.

  17. Plant Physiology and Development

    DEFF Research Database (Denmark)

    Taiz, Lincoln; Zeiger, Eduardo; Møller, Ian Max

    Throughout its twenty-two year history, the authors of Plant Physiology have continually updated the book to incorporate the latest advances in plant biology and implement pedagogical improvements requested by adopters. This has made Plant Physiology the most authoritative, comprehensive......, and widely used upper-division plant biology textbook. In the Sixth Edition, the Growth and Development section (Unit III) has been reorganized and expanded to present the complete life cycle of seed plants from germination to senescence. In recognition of this enhancement, the text has been renamed Plant...... Physiology and Development. As before, Unit III begins with updated chapters on Cell Walls and Signals and Signal Transduction. The latter chapter has been expanded to include a discussion of major signaling molecules, such as calcium ions and plant hormones. A new, unified chapter entitled Signals from...

  18. 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

  19. Reassessing apoptosis in plants.

    Science.gov (United States)

    Dickman, Martin; Williams, Brett; Li, Yurong; de Figueiredo, Paul; Wolpert, Thomas

    2017-10-01

    Cell death can be driven by a genetically programmed signalling pathway known as programmed cell death (PCD). In plants, PCD occurs during development as well as in response to environmental and biotic stimuli. Our understanding of PCD regulation in plants has advanced significantly over the past two decades; however, the molecular machinery responsible for driving the system remains elusive. Thus, whether conserved PCD regulatory mechanisms include plant apoptosis remains enigmatic. Animal apoptotic regulators, including Bcl-2 family members, have not been identified in plants but expression of such regulators can trigger or suppress plant PCD. Moreover, plants exhibit nearly all of the biochemical and morphological features of apoptosis. One difference between plant and animal PCD is the absence of phagocytosis in plants. Evidence is emerging that the vacuole may be key to removal of unwanted plant cells, and may carry out functions that are analogous to animal phagocytosis. Here, we provide context for the argument that apoptotic-like cell death occurs in plants.

  20. Safe genetically engineered plants

    Energy Technology Data Exchange (ETDEWEB)

    Rosellini, D; Veronesi, F [Dipartimento di Biologia Vegetale e Biotecnologie Agroambientali e Zootecniche, Universita degli Studi di Perugia, Borgo XX giugno 74, 06121 Perugia (Italy)

    2007-10-03

    The application of genetic engineering to plants has provided genetically modified plants (GMPs, or transgenic plants) that are cultivated worldwide on increasing areas. The most widespread GMPs are herbicide-resistant soybean and canola and insect-resistant corn and cotton. New GMPs that produce vaccines, pharmaceutical or industrial proteins, and fortified food are approaching the market. The techniques employed to introduce foreign genes into plants allow a quite good degree of predictability of the results, and their genome is minimally modified. However, some aspects of GMPs have raised concern: (a) control of the insertion site of the introduced DNA sequences into the plant genome and of its mutagenic effect; (b) presence of selectable marker genes conferring resistance to an antibiotic or an herbicide, linked to the useful gene; (c) insertion of undesired bacterial plasmid sequences; and (d) gene flow from transgenic plants to non-transgenic crops or wild plants. In response to public concerns, genetic engineering techniques are continuously being improved. Techniques to direct foreign gene integration into chosen genomic sites, to avoid the use of selectable genes or to remove them from the cultivated plants, to reduce the transfer of undesired bacterial sequences, and make use of alternative, safer selectable genes, are all fields of active research. In our laboratory, some of these new techniques are applied to alfalfa, an important forage plant. These emerging methods for plant genetic engineering are briefly reviewed in this work.

  1. Safe genetically engineered plants

    International Nuclear Information System (INIS)

    Rosellini, D; Veronesi, F

    2007-01-01

    The application of genetic engineering to plants has provided genetically modified plants (GMPs, or transgenic plants) that are cultivated worldwide on increasing areas. The most widespread GMPs are herbicide-resistant soybean and canola and insect-resistant corn and cotton. New GMPs that produce vaccines, pharmaceutical or industrial proteins, and fortified food are approaching the market. The techniques employed to introduce foreign genes into plants allow a quite good degree of predictability of the results, and their genome is minimally modified. However, some aspects of GMPs have raised concern: (a) control of the insertion site of the introduced DNA sequences into the plant genome and of its mutagenic effect; (b) presence of selectable marker genes conferring resistance to an antibiotic or an herbicide, linked to the useful gene; (c) insertion of undesired bacterial plasmid sequences; and (d) gene flow from transgenic plants to non-transgenic crops or wild plants. In response to public concerns, genetic engineering techniques are continuously being improved. Techniques to direct foreign gene integration into chosen genomic sites, to avoid the use of selectable genes or to remove them from the cultivated plants, to reduce the transfer of undesired bacterial sequences, and make use of alternative, safer selectable genes, are all fields of active research. In our laboratory, some of these new techniques are applied to alfalfa, an important forage plant. These emerging methods for plant genetic engineering are briefly reviewed in this work

  2. [Intoxications with plants].

    Science.gov (United States)

    Kupper, Jacqueline; Reichert, Cornelia

    2009-05-01

    Ingestions of plants rarely lead to life-threatening intoxications. Highly toxic plants, which can cause death, are monkshood (Aconitum sp.), yew (Taxus sp.) and autumn crocus (Colchicum autumnale). Lethal ingestions of monkshood and yew are usually suicides, intoxications with autumn crocus are mostly accidental ingestions of the leaves mistaken for wild garlic (Allium ursinum). Severe intoxications can occur with plants of the nightshade family like deadly nightshade (Atropa belladonna), angel's trumpet (Datura suaveolens) or jimsonweed (Datura stramonium). These plants are ingested for their psychoactive effects. Ingestion of plant material by children most often only causes minor symptoms or no symptoms at all, as children usually do not eat great quantities of the plants. They are especially attracted by the colorful berries. There are plants with mostly cardiovascular effects like monkshood, yew and Digitalis sp. Some of the most dangerous plants belong to this group. Plants of the nightshade family cause an anticholinergic syndrome. With golden chain (Laburnum anagyroides), castor bean (Ricinus communis) and raw beans (Phaseolus vulgaris) we see severe gastrointestinal effects. Autumn crocus contains a cell toxin, colchicine, which leads to multiorgan failure. Different plants are irritative or even caustic to the skin. Treatment is usually symptomatic. Activated charcoal is administered within one hour after ingestion (1 g/kg). Endoscopic removal of plant material can be considered with ingestions of great quantities of highly toxic plants. Administration of repeated doses of charcoal (1-2 g/h every 2-4 hours) may be effective in case of oleander poisoning. There exist only two antidotes: Anti-digoxin Fab fragments can be used with cardenolide glycoside-containing plants (Digitalis sp., Oleander). Physostigmine is the antidote for severe anticholinergic symptoms of the CNS. Antibodies against colchicine, having been developed in France, are not available at

  3. Nuclear power plants

    International Nuclear Information System (INIS)

    Margulova, T.Ch.

    1976-01-01

    The textbook focuses on the technology and the operating characteristics of nuclear power plants equiped with pressurized water or boiling water reactors, which are in operation all over the world at present. The following topics are dealt with in relation to the complete plant and to economics: distribution and consumption of electric and thermal energy, types and equipment of nuclear power plants, chemical processes and material balance, economical characteristics concerning heat and energy, regenerative preheating of feed water, degassing and condenser systems, water supply, evaporators, district heating systems, steam generating systems and turbines, coolant loops and pipes, plant siting, ventilation and decontamination systems, reactor operation and management, heat transfer including its calculation, design of reactor buildings, and nuclear power plants with gas or sodium cooled reactors. Numerous technical data of modern Soviet nuclear power plants are included. The book is of interest to graduate and post-graduate students in the field of nuclear engineering as well as to nuclear engineers

  4. Conditional sterility in plants

    Science.gov (United States)

    Meagher, Richard B.; McKinney, Elizabeth; Kim, Tehryung

    2010-02-23

    The present disclosure provides methods, recombinant DNA molecules, recombinant host cells containing the DNA molecules, and transgenic plant cells, plant tissue and plants which contain and express at least one antisense or interference RNA specific for a thiamine biosynthetic coding sequence or a thiamine binding protein or a thiamine-degrading protein, wherein the RNA or thiamine binding protein is expressed under the regulatory control of a transcription regulatory sequence which directs expression in male and/or female reproductive tissue. These transgenic plants are conditionally sterile; i.e., they are fertile only in the presence of exogenous thiamine. Such plants are especially appropriate for use in the seed industry or in the environment, for example, for use in revegetation of contaminated soils or phytoremediation, especially when those transgenic plants also contain and express one or more chimeric genes which confer resistance to contaminants.

  5. Plant synthetic biology.

    Science.gov (United States)

    Liu, Wusheng; Stewart, C Neal

    2015-05-01

    Plant synthetic biology is an emerging field that combines engineering principles with plant biology toward the design and production of new devices. This emerging field should play an important role in future agriculture for traditional crop improvement, but also in enabling novel bioproduction in plants. In this review we discuss the design cycles of synthetic biology as well as key engineering principles, genetic parts, and computational tools that can be utilized in plant synthetic biology. Some pioneering examples are offered as a demonstration of how synthetic biology can be used to modify plants for specific purposes. These include synthetic sensors, synthetic metabolic pathways, and synthetic genomes. We also speculate about the future of synthetic biology of plants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Annual Plant Reviews

    DEFF Research Database (Denmark)

    , three dimensional structures and functions of each protein in a biological system. In plant science, the number of proteome studies is rapidly expanding after the completion of the Arabidopsis thaliana genome sequence, and proteome analyses of other important or emerging model systems and crop plants...... are in progress or are being initiated. Proteome analysis in plants is subject to the same obstacles and limitations as in other organisms, but the nature of plant tissues, with their rigid cell walls and complex variety of secondary metabolites, means that extra challenges are involved that may not be faced when...... analysing other organisms. This volume aims to highlight the ways in which proteome analysis has been used to probe the complexities of plant biochemistry and physiology. It is aimed at researchers in plant biochemistry, genomics, transcriptomics and metabolomics who wish to gain an up-to-date insight...

  7. Towards plant wires

    OpenAIRE

    Adamatzky, Andrew

    2014-01-01

    In experimental laboratory studies we evaluate a possibility of making electrical wires from living plants. In scoping experiments we use lettuce seedlings as a prototype model of a plant wire. We approximate an electrical potential transfer function by applying direct current voltage to the lettuce seedlings and recording output voltage. We analyse oscillation frequencies of the output potential and assess noise immunity of the plant wires. Our findings will be used in future designs of self...

  8. Design of chemical plant

    International Nuclear Information System (INIS)

    Lee, Dong Il; Kim, Seung Jae; Yang, Jae Ho; Ryu, Hwa Won

    1993-01-01

    This book describes design of chemical plant, which includes chemical engineer and plan for chemical plant, development of chemical process, cost engineering pattern, design and process development, general plant construction plan, project engineering, foundation for economy on assets and depreciation, estimation for cost on capital investment and manufacturing cost, design with computers optimal design and method like fluid mechanics design chemical device and estimation for cost, such as dispatch of material and device writing on design report and appendixes.

  9. Late Palaeozoic plants.

    Science.gov (United States)

    Feng, Zhuo

    2017-09-11

    Land plants are one of the major constituents of terrestrial ecosystems on Earth, and play an irreplaceable role in human activities today. If we are to understand the extant plants, it is imperative that we have some understanding of the fossil plants from the deep geological past, particularly those that occurred during their early evolutionary history, in the late Palaeozoic. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Plant Habitat (PH)

    Science.gov (United States)

    Onate, Bryan

    2016-01-01

    The International Space Station (ISS) will soon have a platform for conducting fundamental research of Large Plants. Plant Habitat (PH) is designed to be a fully controllable environment for high-quality plant physiological research. PH will control light quality, level, and timing, temperature, CO2, relative humidity, and irrigation, while scrubbing ethylene. Additional capabilities include leaf temperature and root zone moisture and oxygen sensing. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs. There will be several internal cameras (visible and IR) to monitor and record plant growth and operations.

  11. Integrated Nuclear Recycle Plant

    International Nuclear Information System (INIS)

    Patodi, Anuj; Parashar, Abhishek; Samadhiya, Akshay K.; Ray, Saheli; Dey, Mitun; Singh, K.K.

    2017-01-01

    Nuclear Recycle Board (NRB), Tarapur proposes to set up an 'Integrated Nuclear Recycle Plant' at Tarapur. This will be located in the premises of BARC facilities. The project location is at coastal town of Tarapur, 130 Km north of Mumbai. Project area cover of INRP is around 80 hectares. The plant will be designed to process spent fuel received from Pressurized Heavy Water Reactors (PHWRs). This is the first large scale integrated plant of the country. INRP will process spent fuel obtained from indigenous nuclear power plants and perform left over nuclear waste disposal

  12. Towards plant wires.

    Science.gov (United States)

    Adamatzky, Andrew

    2014-08-01

    In experimental laboratory studies we evaluate a possibility of making electrical wires from living plants. In scoping experiments we use lettuce seedlings as a prototype model of a plant wire. We approximate an electrical potential transfer function by applying direct current voltage to the lettuce seedlings and recording output voltage. We analyse oscillation frequencies of the output potential and assess noise immunity of the plant wires. Our findings will be used in future designs of self-growing wetware circuits and devices, and integration of plant-based electronic components into future and emergent bio-hybrid systems. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. MBS Native Plant Communities

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data layer contains results of the Minnesota County Biological Survey (MCBS). It includes polygons representing the highest quality native plant communities...

  14. The Kuroshio power plant

    CERN Document Server

    Chen, Falin

    2013-01-01

    By outlining a new design or the Kuroshio power plant, new approaches to turbine design, anchorage system planning, deep sea marine engineering and power plant operations and maintenance are explored and suggested. The impact on the local environment, particularly in the face of natural disasters, is also considered to provide a well rounded introduction to plan and build a 30MW pilot power plant. Following a literature review, the six chapters of this book propose a conceptual design by focusing on the plant's core technologies and establish the separate analysis logics for turbine design and

  15. 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....

  16. Less power plants

    International Nuclear Information System (INIS)

    TASR

    2003-01-01

    In the Slovak Republic the number of company power plants decreased as against 2001 by two sources. In present time only 35 companies have their own power plants. The companies Slovnaft, Kappa Sturovo, Slovensky hodvab Senica, Matador Puchov, Maytex Liptovsky MikuIas, Kovohuty Krompachy, Chemko Strazske and some Slovak sugar factories belong to the largest company power plants in force of distributing companies. Installed output of present 35 company sources is 531 MW. The largest of separate power plants as Paroplynovy cyklus Bratislava (218 MW) and VD Zilina (72 MW) belong to independent sources. Total installed output of Slovak sources was 8306 MW in the end of last year

  17. Offshore atomic power plants

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Various merits of offshore atomic power plants are illustrated, and their systems are assessed. The planning of the offshore atomic power plants in USA is reviewed, and the construction costs of the offshore plant in Japan were estimated. Air pollution problem may be solved by the offshore atomic power plants remarkably. Deep water at low temperature may be advantageously used as cooling water for condensers. Marine resources may be bred by building artificial habitats and by providing spring-up equipments. In the case of floating plants, the plant design can be standardized so that the construction costs may be reduced. The offshore plants can be classified into three systems, namely artificial island system, floating system and sea bottom-based system. The island system may be realized with the present level of civil engineering, but requires the development of technology for the resistance of base against earthquake and its calculation means. The floating system may be constructed with conventional power plant engineering and shipbuilding engineering, but the aseismatic stability of breakwater may be a problem to be solved. Deep water floating system and deep water submerging system are conceivable, but its realization may be difficult. The sea bottom-based system with large caissons can be realized by the present civil engineering, but the construction of the caissons, stability against earthquake and resistance to waves may be problems to be solved. The technical prediction and assessment of new plant sites for nuclear power plants have been reported by Science and Technology Agency in 1974. The construction costs of an offshore plant has been estimated by the Ministry of International Trade and Industry to be yen71,026/kW as of 1985. (Iwakiri, K.)

  18. Selenium accumulation by plants

    Science.gov (United States)

    White, Philip J.

    2016-01-01

    Background Selenium (Se) is an essential mineral element for animals and humans, which they acquire largely from plants. The Se concentration in edible plants is determined by the Se phytoavailability in soils. Selenium is not an essential element for plants, but excessive Se can be toxic. Thus, soil Se phytoavailability determines the ecology of plants. Most plants cannot grow on seleniferous soils. Most plants that grow on seleniferous soils accumulate 100 mg Se kg–1 dry matter. These plants are considered to be Se accumulators. Some species can even accumulate Se concentrations of 1000–15 000 mg Se kg–1 dry matter and are called Se hyperaccumulators. Scope This article provides an overview of Se uptake, translocation and metabolism in plants and highlights the possible genetic basis of differences in these between and within plant species. The review focuses initially on adaptations allowing plants to tolerate large Se concentrations in their tissues and the evolutionary origin of species that hyperaccumulate Se. It then describes the variation in tissue Se concentrations between and within angiosperm species and identifies genes encoding enzymes limiting the rates of incorporation of Se into organic compounds and chromosomal loci that might enable the development of crops with greater Se concentrations in their edible portions. Finally, it discusses transgenic approaches enabling plants to tolerate greater Se concentrations in the rhizosphere and in their tissues. Conclusions The trait of Se hyperaccumulation has evolved several times in separate angiosperm clades. The ability to tolerate large tissue Se concentrations is primarily related to the ability to divert Se away from the accumulation of selenocysteine and selenomethionine, which might be incorporated into non-functional proteins, through the synthesis of less toxic Se metabilites. There is potential to breed or select crops with greater Se concentrations in their edible tissues, which

  19. Better Plants Program Overview

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-09-30

    The U.S. Department of Energy’s (DOE’s) Better Buildings, Better Plants Program is a voluntary partnership initiative to drive significant energy efficiency improvement across energy intensive companies and organizations. 157 leading manufacturers and public water and wastewater treatment utilities are partnering with DOE through Better Plants to improve energy efficiency, slash carbon emissions, and cut energy costs.

  20. Plant Glandular Trichomes

    Indian Academy of Sciences (India)

    landing on the plant. Glandular trichomes in catmint (Nepeta sp.) produce nepetalactone, closely related to the aphid sex pheromone, nepetalactol. Nepetalactone can be reduced to the corresponding nepetalactol. ... Plant glandular trichomes function either as repositories or releasing sites of various chemicals. Interest in ...

  1. Plants as green phones

    NARCIS (Netherlands)

    Soler, R.; Harvey, J.A.; Bezemer, T.M.; Stuefer, J.F.

    2008-01-01

    Plants can act as vertical communication channels or `green phones¿ linking soil-dwelling insects and insects in the aboveground ecosystem. When root-feeding insects attack a plant, the direct defense system of the shoot is activated, leading to an accumulation of phytotoxins in the leaves. The

  2. Solar thermal power plants

    International Nuclear Information System (INIS)

    Schnatbaum, L.

    2009-01-01

    The solar thermal power plant technology, the opportunities it presents and the developments in the market are outlined. The focus is on the technology of parabolic trough power plants, a proven technology for solar power generation on a large scale. In a parabolic trough power plant, trough-shaped mirrors concentrate the solar irradiation onto a pipe in the focal line of the collector. The thermal energy thus generated is used for electricity generation in a steam turbine. Parabolic trough plants can be combined with thermal storage and fossil or biomass fired heat exchangers to generate electricity even when the sun is not shining. Solar Millennium AG in Erlangen has developed the first power plant of this kind in Europe. After two years of construction the plant started operation in Southern Spain in 2008. This one and its sister projects are important steps leading the way for the whole market. The paper also covers the technological challenges, the key components used and the research and development activities concerning this technology. Solar thermal power plants are ideal for covering peak and medium loads in power grids. In hybrid operation they can also cover base-load. The Solar Chimney power plant, another striking technology for the conversion of solar into electric energy, is described briefly. The paper concludes with a look at the future - the import of solar energy from the deserts of North Africa to central Europe. (author)

  3. Redox signaling in plants.

    Science.gov (United States)

    Foyer, Christine H; Noctor, Graham

    2013-06-01

    Our aim is to deliver an authoritative and challenging perspective of current concepts in plant redox signaling, focusing particularly on the complex interface between the redox and hormone-signaling pathways that allow precise control of plant growth and defense in response to metabolic triggers and environmental constraints and cues. Plants produce significant amounts of singlet oxygen and other reactive oxygen species (ROS) as a result of photosynthetic electron transport and metabolism. Such pathways contribute to the compartment-specific redox-regulated signaling systems in plant cells that convey information to the nucleus to regulate gene expression. Like the chloroplasts and mitochondria, the apoplast-cell wall compartment makes a significant contribution to the redox signaling network, but unlike these organelles, the apoplast has a low antioxidant-buffering capacity. The respective roles of ROS, low-molecular antioxidants, redox-active proteins, and antioxidant enzymes are considered in relation to the functions of plant hormones such as salicylic acid, jasmonic acid, and auxin, in the composite control of plant growth and defense. Regulation of redox gradients between key compartments in plant cells such as those across the plasma membrane facilitates flexible and multiple faceted opportunities for redox signaling that spans the intracellular and extracellular environments. In conclusion, plants are recognized as masters of the art of redox regulation that use oxidants and antioxidants as flexible integrators of signals from metabolism and the environment.

  4. Cognition in plants

    NARCIS (Netherlands)

    Calvo, P.; Keijzer, F.A.

    2009-01-01

    To what extent can plants be considered cognitive from the perspective of embodied cognition? Cognition is interpreted very broadly within embodied cognition, and the current evidence for plant intelligence might find an important theoretical background here. However, embodied cognition does stress

  5. Invertebrates and Plants

    Science.gov (United States)

    Wendell R. Haag; Robert J. Distefano; Siobhan Fennessy; Brett D. Marshall

    2013-01-01

    Invertebrates and plants are among the most ubiquitous and abundant macroscopic organisms in aquatic ecosystems; they dominate most habitats in both diversity and biomass and play central roles in aquatic food webs. Plants regulate and create habitats for a wide array of organisms (Cooke et al. 2005). Snail grazing and bivalve filtering profoundly alter habitats and...

  6. Modulating lignin in plants

    Science.gov (United States)

    Apuya, Nestor; Bobzin, Steven Craig; Okamuro, Jack; Zhang, Ke

    2013-01-29

    Materials and methods for modulating (e.g., increasing or decreasing) lignin content in plants are disclosed. For example, nucleic acids encoding lignin-modulating polypeptides are disclosed as well as methods for using such nucleic acids to generate transgenic plants having a modulated lignin content.

  7. Recognizing Plant Defense Priming

    NARCIS (Netherlands)

    Martinez-Medina, Ainhoa; Flors, Victor; Heil, Martin; Mauch-Mani, Brigitte; Pieterse, Corné M J|info:eu-repo/dai/nl/113115113; Pozo, Maria J; Ton, Jurriaan; van Dam, Nicole M; Conrath, Uwe

    2016-01-01

    Defense priming conditions diverse plant species for the superinduction of defense, often resulting in enhanced pest and disease resistance and abiotic stress tolerance. Here, we propose a guideline that might assist the plant research community in a consistent assessment of defense priming in

  8. Exotic invasive plants

    Science.gov (United States)

    Carolyn Hull Sieg; Barbara G. Phillips; Laura P. Moser

    2003-01-01

    Ecosystems worldwide are threatened by nonnative plant invasions that can cause undesirable, irreversible changes. They can displace native plants and animals, out-cross with native flora, alter nutrient cycling and other ecosystem functions, and even change an ecosystem's flammability (Walker and Smith 1997). After habitat loss, the spread of exotic species is...

  9. Plant-Fungus Marriages

    Indian Academy of Sciences (India)

    Every plant requires mineral elements for growth. A mnemonic ... lar coils. More commonly, the hypha forms highly branched, .... stamps on the edible and poisonous mushrooms (Figure 2). One of the ... but these days dogs are used for truffle. 'hunting' . .... example is a non-chlorophyllous plant known as Indian pipe or.

  10. Dormancy in Plant Seeds

    NARCIS (Netherlands)

    Hilhorst, H.W.M.; Finch-Savage, W.E.; Buitink, J.; Bolingue, W.; Leubner-Metzger, G.

    2010-01-01

    Seed dormancy has been studied intensely over the past decades and, at present, knowledge of this plant trait is at the forefront of plant biology. The main model species is Arabidopsis thaliana, an annual weed, possessing nondeep physiological dormancy. This overview presents the state-of-the-art

  11. Slavery in plants

    NARCIS (Netherlands)

    Kabiri, S.; Rodenburg, J.; Ast, van A.; Bastiaans, L.

    2017-01-01

    The rain-fed lowland rice weed Rhamphicarpa fistulosa (Rice Vampireweed) is a facultative root parasitic plant. Growth and reproduction of R. fistulosa benefit considerably from parasitism, but how this affects the host plant is not well established. We determined accumulation and partitioning of

  12. Power plant chemical technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    17 contributions covering topies of fossil fuel combustion, flue gas cleaning, power plant materials, corrosion, water/steam cycle chemistry, monitoring and control were presented at the annual meeting devoted to Power Plant Chemical Technology 1996 at Kolding (Denmark) 4-6 September 1996. (EG)

  13. Plant diagnosis device

    International Nuclear Information System (INIS)

    Tozuka, Shin-ichi.

    1996-01-01

    Standard data approximately defined are inputted as 1:1 functional data between at least two or more plant data and each of plant data are inputted. Diagnosis data corresponding to each of process data are formed based on the functional data. Limit value data to be a threshold value which determines whether the diagnosis data are in a predetermined state or not are formed. The diagnosis data and the limit value data are displayed in a recognizable state. If diagnosis data of a plurality of plants are displayed simultaneously, all of the plant data are substantially the same value with one standard datum if the plant is in a normal state. When abnormality should occur in the plant, the difference between the diagnosis data and the standard data is remarkable, and the difference between the diagnosis data of other normal plant data and the standard data are also made remarkably, accordingly, the display of a plurality of diagnosis data is scattered thereby capable of diagnosing the abnormality of the plant. (N.H.)

  14. Methylome evolution in plants

    NARCIS (Netherlands)

    Vidalis, Amaryllis; Živković, Daniel; Wardenaar, René; Roquis, David; Tellier, Aurélien; Johannes, Frank

    2016-01-01

    Despite major progress in dissecting the molecular pathways that control DNA methylation patterns in plants, little is known about the mechanisms that shape plant methylomes over evolutionary time. Drawing on recent intra- and interspecific epigenomic studies, we show that methylome evolution over

  15. Antimicrobial Peptides from Plants

    Directory of Open Access Journals (Sweden)

    James P. Tam

    2015-11-01

    Full Text Available Plant antimicrobial peptides (AMPs have evolved differently from AMPs from other life forms. They are generally rich in cysteine residues which form multiple disulfides. In turn, the disulfides cross-braced plant AMPs as cystine-rich peptides to confer them with extraordinary high chemical, thermal and proteolytic stability. The cystine-rich or commonly known as cysteine-rich peptides (CRPs of plant AMPs are classified into families based on their sequence similarity, cysteine motifs that determine their distinctive disulfide bond patterns and tertiary structure fold. Cystine-rich plant AMP families include thionins, defensins, hevein-like peptides, knottin-type peptides (linear and cyclic, lipid transfer proteins, α-hairpinin and snakins family. In addition, there are AMPs which are rich in other amino acids. The ability of plant AMPs to organize into specific families with conserved structural folds that enable sequence variation of non-Cys residues encased in the same scaffold within a particular family to play multiple functions. Furthermore, the ability of plant AMPs to tolerate hypervariable sequences using a conserved scaffold provides diversity to recognize different targets by varying the sequence of the non-cysteine residues. These properties bode well for developing plant AMPs as potential therapeutics and for protection of crops through transgenic methods. This review provides an overview of the major families of plant AMPs, including their structures, functions, and putative mechanisms.

  16. Nuclear Power Plants. Revised.

    Science.gov (United States)

    Lyerly, Ray L.; Mitchell, Walter, III

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Among the topics discussed are: Why Use Nuclear Power?; From Atoms to Electricity; Reactor Types; Typical Plant Design Features; The Cost of Nuclear Power; Plants in the United States; Developments in Foreign…

  17. NUCLEAR POWER PLANT

    Science.gov (United States)

    Carter, J.C.; Armstrong, R.H.; Janicke, M.J.

    1963-05-14

    A nuclear power plant for use in an airless environment or other environment in which cooling is difficult is described. The power plant includes a boiling mercury reactor, a mercury--vapor turbine in direct cycle therewith, and a radiator for condensing mercury vapor. (AEC)

  18. Caladium plant poisoning

    Science.gov (United States)

    ... enough to prevent normal speaking and swallowing. Home Care If the plant was eaten, wipe out the mouth with a ... to Expect at the Emergency Room Take the plant with you to the hospital, if possible. The health care provider will measure and monitor the person's vital ...

  19. Gold in plants

    International Nuclear Information System (INIS)

    Girling, C.A.; Peterson, P.J.

    1980-01-01

    Many plants have the ability to take up gold from the soil and to accumulate it in their tisssue. Advances have been made in understanding these processes to the point where their exploitation in the field of prospecting for gold appears practically feasible. Neutron activation analysis is used for the determination of the small quantities of gold in plants

  20. Recognizing plant defense priming

    NARCIS (Netherlands)

    Martinez-Medina, A.; Flors, V.; Heil, M.; Mauch-Mani, B.; Pieterse, C.M.J.; Pozo, M.J.; Ton, J.; Van Dam, N.M.; Conrath, U.

    2016-01-01

    Defense priming conditions diverse plant species for the superinduction of defense, often resulting in enhanced pest and disease resistance and abiotic stress tolerance. Here, we propose a guideline that might assist the plant research community in a consistent assessment of defense priming in

  1. Carotenoid metabolism in plants

    Science.gov (United States)

    Carotenoids are mostly C40 terpenoids, a class of hydrocarbons that participate in various biological processes in plants, such as photosynthesis, photomorphogenesis, photoprotection, and development. Carotenoids also serve as precursors for two plant hormones and a diverse set of apocarotenoids. Th...

  2. [Neotropical plant morphology].

    Science.gov (United States)

    Pérez-García, Blanca; Mendoza, Aniceto

    2002-01-01

    An analysis on plant morphology and the sources that are important to the morphologic interpretations is done. An additional analysis is presented on all published papers in this subject by the Revista de Biología Tropical since its foundation, as well as its contribution to the plant morphology development in the neotropics.

  3. Automatic micropropagation of plants

    Science.gov (United States)

    Otte, Clemens; Schwanke, Joerg; Jensch, Peter F.

    1996-12-01

    Micropropagation is a sophisticated technique for the rapid multiplication of plants. It has a great commercial potential due to the speed of propagation, the high plant quality, and the ability to produce disease-free plants. However, micropropagation is usually done by hand which makes the process cost-intensive and tedious for the workers especially because it requires a sterile work-place. Therefore, we have developed a prototype automation system for the micropropagation of a grass species (miscanthus sinensis gigantheus). The objective of this paper is to describe the robotic system in an overview and to discuss the vision system more closely including the implemented morphological operations recognizing the cutting and gripping points of miscanthus plants. Fuzzy controllers are used to adapt the parameters of image operations on-line to each individual plant. Finally, we discuss our experiences with the developed prototype an give a preview of a possible real production line system.

  4. Plants and fluorine

    Energy Technology Data Exchange (ETDEWEB)

    Garber, K

    1962-01-01

    A report is given about the contents of fluorine in soil and different plants. It is stated that spinach and several spice herbages are rich in fluorine (0.98 - 21.8 ppm) while in other plants are not more than 5 ppm maximum. An exception is found in Thea sinensis with 178 ppm and more. Tea is, therefore, a source of fluorine for contamination of the human body. An increase of the fluorine contents of plants by manuring with F-salts or mineral manure is possible but of long duration. Damage to plants by uptake of fluorine from soil as well as in a gaseous condition from the atmosphere are described. The rate of damage is related to the type of soil in which the plant is grown.

  5. Poultry Plant Noise Control

    Science.gov (United States)

    1982-01-01

    A demonstration conducted last winter at the Tip Top Poultry Plant intended to show poultry plant managers from all over the U.S. potential solutions to the problem of plant noise. Plastic covers used over sound absorbing materials need to meet cleanability requirements, high- pressure water cleaning and other harsh maintenance procedures peculiar to the poultry processing industry. For the demonstration, Fiber Flex, Inc. manufactured and donated 750 noise panels; Owens-Corning Fiberglas Corporation donated the fiberglas cores; and the cover material was purchased from Howe and Bainbridge. The Engineering Experiment Station (EES) conducted before and after noise surveys and is evaluating the effect of noise reduction on turnover and productivity in the demonstration plant. EES plans to conduct a noise abatement workshop and update a handbook to help poultry processors with noise problems. EES study and demonstration may be applicable to other food processing plants where similar sanitary constraints exist.

  6. Protein carbonylation in plants

    DEFF Research Database (Denmark)

    Møller, Ian Max; Havelund, Jesper; Rogowska-Wrzesinska, Adelina

    2017-01-01

    This chapter provides an overview of the current knowledge on protein carbonylation in plants and its role in plant physiology. It starts with a brief outline of the turnover and production sites of reactive oxygen species (ROS) in plants and the causes of protein carbonylation. This is followed...... by a description of the methods used to study protein carbonylation in plants, which is also very brief as the methods are similar to those used in studies on animals. The chapter also focuses on protein carbonylation in plants in general and in mitochondria and in seeds in particular, as case stories where...... specific carbonylated proteins have been identified. Protein carbonylation appears to accumulate at all stages of seed development and germination investigated to date. In some cases, such as seed aging, it is probably simply an accumulation of oxidative damage. However, in other cases protein...

  7. Plant control device

    International Nuclear Information System (INIS)

    Sato, Masuo; Ono, Makoto.

    1995-01-01

    A plant control device comprises an intellectual instrumentation group for measuring a predetermined process amount, an intellectual equipment group operating in accordance with a self-countermeasure, a system information space for outputting system information, a system level monitoring and diagnosing information generalization section for outputting system information, a system level maintenance information generalization section for outputting information concerning maintenance, a plant level information space and a plant level information generalization section. Each of them determines a state of the plant autonomously, and when abnormality is detected, each of the intellectual instrumentation, equipments and systems exchange information with each other, to conduct required operations including operations of intellectual robots, as required. Appropriate countermeasures for gauges, equipments and systems can be conducted autonomously at a place where operators can not access to improve reliability of complicate operations in the working site, as well as improve plant safety and reliability. (N.H.)

  8. Plant abnormality inspection device

    International Nuclear Information System (INIS)

    Takenaka, Toshio.

    1990-01-01

    The present invention concerns a plant abnormality inspection device for conducting remote or automatic patrolling inspection in a plant and, more particularly, relates to such a device as capable of detecting abnormal odors. That is, the device comprises a moving device for moving to a predetermined position in the plant, a plurality of gas sensors for different kind of gases to be inspected mounted thereon, a comparator for comparing the concentration of a gas detected by the gas sensor with the normal gas concentration at the predetermined position and a judging means for judging the absence or presence of abnormality depending on the combination of the result of the comparison and deliverying a signal if the state is abnormal. As a result, a slight amount of gas responsible to odors released upon abnormality of the plant can be detected by a plurality of gas sensors for different kinds gases to rapidly and easily find abnormal portions in the plant. (I.S.)

  9. Nuclear power plant siting

    International Nuclear Information System (INIS)

    Sulkiewicz, M.; Navratil, J.

    The construction of a nuclear power plant is conditioned on territorial requirements and is accompanied by the disturbance of the environment, land occupation, population migration, the emission of radioactive wastes, thermal pollution, etc. On the other hand, a nuclear power plant makes possible the introduction of district heating and increases the economic and civilization activity of the population. Due to the construction of a nuclear power plant the set limits of negative impacts must not be exceeded. The locality should be selected such as to reduce the unfavourable effects of the plant and to fully use its benefits. The decision on the siting of the nuclear power plant is preceded by the processing of a number of surveys and a wide range of documentation to which the given criteria are strictly applied. (B.H.)

  10. Manganese deficiency in plants

    DEFF Research Database (Denmark)

    Schmidt, Sidsel Birkelund; Jensen, Poul Erik; Husted, Søren

    2016-01-01

    Manganese (Mn) is an essential plant micronutrient with an indispensable function as a catalyst in the oxygen-evolving complex (OEC) of photosystem II (PSII). Even so, Mn deficiency frequently occurs without visual leaf symptoms, thereby masking the distribution and dimension of the problem...... restricting crop productivity in many places of the world. Hence, timely alleviation of latent Mn deficiency is a challenge in promoting plant growth and quality. We describe here the key mechanisms of Mn deficiency in plants by focusing on the impact of Mn on PSII stability and functionality. We also address...... the mechanisms underlying the differential tolerance towards Mn deficiency observed among plant genotypes, which enable Mn-efficient plants to grow on marginal land with poor Mn availability....

  11. Communal biomass conversion plants

    International Nuclear Information System (INIS)

    Holm-Nielsen, J.B.; Huntingford, S.; Halberg, N.

    1993-03-01

    The aim was to show the agricultural advantages of farmers being in connection with Communal Biogas Plant. Whether a more environmentally protectire distribution of plant nutrients from animal manure takes place through a biogas plants distribution system, whether the nitrogen in the digested slurry is better utilized and whether the connection results in slurry transportation-time reduction, are discussed. The average amount of nitrogen from animal manure used per hectare was reduced. The area of manure distribution was larger. The nitrogen efficiency was increased when using digested slurry and purchase of N mineral fertilizer decreased, resulting in considerable reduction in nitrogen leaching. The amount of slurry delivered to the local storage tanks was approximately 45 per cent of the total amount treated on the biogas plant. Conditions of manure transport improved greatly as this was now the responsibility of the communal biomass conversion plant administrators. (AB) (24 refs.)

  12. Carbono orgânico, nitrogênio total, biomassa e atividade microbiana do solo em duas cronosseqüências de reabilitação após a mineração de bauxita Soil organic carbon, total nitrogen, microbial biomass and activity in two rehabilitation chronosequences after bauxite mining

    Directory of Open Access Journals (Sweden)

    Marco Aurélio Carbone Carneiro

    2008-04-01

    reas de referência a partir do primeiro ano, enquanto para o CO e o Nt estes só foram alcançados de modo consistente em períodos mais longos de reabilitação (18 anos. O coeficiente metabólico (qCO2 foi indicativo do estresse provocado pela mineração, mas não diferenciou os diferentes tempos de reabilitação. Os resultados deste estudo mostram que os atributos essenciais ao funcionamento adequado do solo são recuperáveis pela revegetação.Mining is a human activity with a harsh impact on ecosystems. The degradation degree depends on the intensity of soil impact, exploited soil volume and amount of mine spoil. Soil microbial activities are responsible for key functions in ecosystems and can indicate the degree of rehabilitation of mined areas. The purpose of this study was to evaluate the impact of bauxite mining in two chronosequences with different rehabilitation strategies (revegetation on the following soil attributes: organic carbon (C org, total nitrogen (Nt, microbial biomass and respiration, and enzymatic activities. The study was developed in mining areas owned by Alcoa S/A in two different environments: (a areas originally covered by a tropical prairie vegetation called "campo", at elevations up to 1,000 masl, and (b in hilly areas, on the plateau top, including remnants of the native vegetation cover, represented by a subtropical decidous forest, at elevations about 1.600 masl, called "serra". Rehabilitation differed depending on strategies and time, varying from recent mining to 19 years of rehabilitation. Composite samples were collected in eight "campo" and nine "serra" areas, in two layers (0-10 and 10-20 cm in the winter as well as in the summer, in three replicates. Bauxite mining caused a negative impact on org C, Nt and microbial biomass (C, N and P. The values of these attributes were reduced by up to 99 % in comparison with those in reference areas (native vegetation. In both "campo" and "serra", the C org, Nt, microbial biomass and

  13. Encapsulation plant at Forsmark

    International Nuclear Information System (INIS)

    Nystroem, Anders

    2007-08-01

    SKB has already carried out a preliminary study of an encapsulation plant detached from Clab (Central interim storage for spent fuels). This stand-alone encapsulation plant was named FRINK and its assumed siting was the above-ground portion of the final repository, irrespective of the repository's location. The report previously presented was produced in cooperation with BNFL Engineering Ltd in Manchester and the fuel reception technical solution was examined by Gesellschaft fuer Nuklear-Service mbH (GNS) in Hannover and by Societe Generale pour les Techniques Nouvelles (SGN) in Paris. This report is an update of the earlier preliminary study report and is based on the assumption that the encapsulation plant and also the final repository will be sited in the Forsmark area. SKB's main alternative for siting the encapsulation plant is next to Clab. Planning of this facility is ongoing and technical solutions from the planning work have been incorporated in this report. An encapsulation plant placed in proximity to any final repository in Forsmark forms part of the alternative presentation in the application for permission to construct and operate an installation at Clab. The main technical difference between the planned encapsulation plant at Clab and an encapsulation plant at a final repository at Forsmark is how the fuel is managed and prepared before actual encapsulation. Fuel reception at the encapsulation plant in Forsmark would be dry, i.e. there would be no water-filled pools at the facility. Clab is used for verificatory fuel measurements, sorting and drying of the fuel before transport to Forsmark. This means that Clab will require a measure of rebuilding and supplementary equipment. In purely technical terms, the prospects for building an encapsulation plant sited at Forsmark are good. A description of the advantages and drawbacks of siting the encapsulation plant at Clab as opposed to any final repository at Forsmark is presented in a separate report

  14. Encapsulation plant at Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Nystroem, Anders

    2007-08-15

    SKB has already carried out a preliminary study of an encapsulation plant detached from Clab (Central interim storage for spent fuels). This stand-alone encapsulation plant was named FRINK and its assumed siting was the above-ground portion of the final repository, irrespective of the repository's location. The report previously presented was produced in cooperation with BNFL Engineering Ltd in Manchester and the fuel reception technical solution was examined by Gesellschaft fuer Nuklear-Service mbH (GNS) in Hannover and by Societe Generale pour les Techniques Nouvelles (SGN) in Paris. This report is an update of the earlier preliminary study report and is based on the assumption that the encapsulation plant and also the final repository will be sited in the Forsmark area. SKB's main alternative for siting the encapsulation plant is next to Clab. Planning of this facility is ongoing and technical solutions from the planning work have been incorporated in this report. An encapsulation plant placed in proximity to any final repository in Forsmark forms part of the alternative presentation in the application for permission to construct and operate an installation at Clab. The main technical difference between the planned encapsulation plant at Clab and an encapsulation plant at a final repository at Forsmark is how the fuel is managed and prepared before actual encapsulation. Fuel reception at the encapsulation plant in Forsmark would be dry, i.e. there would be no water-filled pools at the facility. Clab is used for verificatory fuel measurements, sorting and drying of the fuel before transport to Forsmark. This means that Clab will require a measure of rebuilding and supplementary equipment. In purely technical terms, the prospects for building an encapsulation plant sited at Forsmark are good. A description of the advantages and drawbacks of siting the encapsulation plant at Clab as opposed to any final repository at Forsmark is presented in a separate

  15. Biofuelled heating plants

    International Nuclear Information System (INIS)

    Gulliksson, Hans; Wennerstaal, L.; Zethraeus, B.; Johansson, Bert-Aake

    2001-11-01

    The purpose of this report is to serve as a basis to enable establishment and operation of small and medium-sized bio-fuel plants, district heating plants and local district heating plants. Furthermore, the purpose of this report is to serve as a guideline and basis when realizing projects, from the first concept to established plant. Taking into account all the phases, from selection of heating system, fuel type, selection of technical solutions, authorization request or application to operate a plant, planning, construction and buying, inspection, performance test, take-over and control system of the plant. Another purpose of the report is to make sure that best available technology is used and to contribute to continuous development of the technology. The report deals mainly with bio-fuelled plants in the effect range 0.3 to10 MW. The term 'plant' refers to combined power and heating plants as well as 'simpler' district heating plants. The last-mentioned is also often referred to as 'local heating plant'. In this context, the term bio fuel refers to a wide range of fuel types. The term bio fuel includes processed fractions like powders, pellets, and briquettes along with unprocessed fractions, such as by-products from the forest industry; chips and bark. Bio fuels also include straw, energy crops and cereal waste products, but these have not been expressly studied in this report. The report is structured with appendixes regarding the various phases of the projects, with the purpose of serving as a helping handbook, or manual for new establishment, helping out with technical and administrative advice and environmental requirements. Plants of this size are already expanding considerably, and the need for guiding principles for design/technology and environmental requirements is great. These guiding principles should comply with the environmental legislation requirements, and must contain advice and recommendations for bio fuel plants in this effect range, also in

  16. Populations in clonal plants

    Directory of Open Access Journals (Sweden)

    Jussi Tammisola

    1986-12-01

    Full Text Available Population phenomena in higher plants are reviewed critically, particularly in relation to clonality. An array of concepts used in the field are discussed. In contrast to animals, higher plants are modular in structure. Plant populations show hierarchy at two levels: ramets and genets. In addition, their demography is far more complicated, since even the direction of development of a ramet may change by rejuvenation. Therefore, formulae concerning animal populations often require modification for plants. Furthermore, at the zygotic stage, higher plants are generally less mobile than animals. Accordingly, their population processes tend to be more local. Most populations of plants have a genetic structure: alleles and genotypes are spatially aggregated. Due to the short-ranged foraging behaviour of pollinators, genetically non-random pollination prevails. A generalized formula for parent-offspring dispersal variance is derived. It is used to analyze the effect of clonality on genetic patchiness in populations. In self-compatible species, an increase in clonality will tend to increase the degree of patchiness, while in self-incompatible species a decrease may result. Examples of population structure studies in different species are presented. A considerable degree of genetic variation appears to be found also in the populations of species with a strong allocation of resources to clonal growth or apomictic seed production. Some consequences of clonality are considered from the point of view of genetic conservation and plant breeding.

  17. Experimental mutagenesis in plants

    International Nuclear Information System (INIS)

    Conger, B.V.

    1979-01-01

    Considerable progress has been made in directed or controlled mutagenesis with bacterial systems, the genetic resolving power of which is much greater than that of higher plants. The mutagen specificity in higher plants has been of great interest, and numerous results and observations have been reported. The advances in the culture of plant cells and tissues have created much interest concerning the possibility of inducing and recovering mutants at the cellular level. There are great problems including the failure to regenerate plants from cells in all but a few species. The genetic and cytogenetic instability in the culture of plant tissues is well known, and the most common nuclear change is polyploidy including aneuploidy. The degree of polyploidy increases with calluses or culture age. In rice, the frequency of aneuploidy is greater in the calluses derived from roots than those derived from stem internodes. Polyploid and/or self-incompatible plant species are not as amenable to conventional mutation breeding techniques as diploid, self-fertilizing species. Inducing mutations in somatic tissues creates the problem of chimeras. However, the new cultivars of highly heterozygous, outcrossing, self-incompatible species are produced by combining several different clones. The performance of the progeny of at least 4 generations removed from the polycross of the parent clones is the important factor, and a high amount of heterozygocity is tolerated within cultivars and even on the same plants. (Yamashita, S.)

  18. Plant state display device

    International Nuclear Information System (INIS)

    Kadota, Kazuo; Ito, Toshiichiro.

    1994-01-01

    The device of the present invention conducts information processing suitable for a man to solve a problem in a plant such as a nuclear power plant incorporating a great amount of information, where safety is required and provides information to an operator. Namely, theories and rules with respect to the flow and balanced state of materials and energy upon plant start-up, and a vapor cycle of operation fluids are symbolized and displayed on the display screen of the device. Then, the display of the plant information suitable to the information processing for a man to dissolve problems is provided. Accordingly, a mechanism for analyzing a purpose of the plant is made more definite, thereby enabling to prevent an erroneous judgement of an operator and occurrence of plant troubles. In addition, a simular effect can also be expected when the theories and rules with respect to the flow and the balanced state of materials and energy and thermohydrodynamic behavior of the operation fluids in a state of after-heat removing operation during shutdown of the plant are symbolized and displayed. (I.S.)

  19. Physiology of woody plants

    CERN Document Server

    Hazewinkel, Michiel; Pallardy, Stephen G

    1996-01-01

    This completely revised classic volume is an up-to-date synthesis of the intensive research devoted to woody plants. Intended primarily as a text for students and a reference for researchers, this interdisciplinary book should be useful to a broad range of scientists from agroforesters, agronomists, and arborists to plant pathologists, ecophysiologists, and soil scientists. Anyone interested in plant physiology will find this text invaluable. Key Features * Includes supplementary chapter summaries and lists of general references * Provides a solid foundation of reference information * Thoroughly updated classic text/reference.

  20. Interelement correlations in plants

    International Nuclear Information System (INIS)

    Markert, B.

    1987-01-01

    The concentration of 25 elements in 4 plant species (Citrus aurantia, Brassica oleracea, Lycopersicon esculentum and Pinus strobus) were linearly correlated. For some element pairs (Ce-Fe, Ce-Ni, Ce-Sb, Ce-Sc, Ce-Zn, Fe-Sb, Fe-Sc, Fe-U, Fe-Zn, K-Cd, La-U, Ni-Sb, Sc-U and Sc-Zn) a high positive correlation coefficient (r = +1) was found. The element pairs Ca-Mg, Hg-U, Ni-Sr and Sr-Zn show a significant negative correlation (r = -1). Plants seem to process some constant interelement relations, independent of plant species. (orig.)

  1. Radiation hormesis in plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Sung; Song, Hi Sup; Lee, Young Keun; Lee, Byung Hun; Shin, In Chul; Lim, Young Taek

    2000-04-01

    This research was performed to investigate the effects of low dose {gamma}-ray radiation on the seed germination and the following physiological responses in vegetable crops. Special attention was focused on whether the resistance of vegetables against the unfavorable conditions of environment such as subsequent high doses of radiation or Phytophthora blight of pepper could be enhanced as an aspect of radiation hormesis. Analysis and characterization of antioxidant enzyme from plant culture cells and radiation tolerant of transformed plants from antioxidant (POD) were accomplished in the plant irradiated with different dose of {gamma}-ray. (author)

  2. Selenium accumulation by plants.

    Science.gov (United States)

    White, Philip J

    2016-02-01

    Selenium (Se) is an essential mineral element for animals and humans, which they acquire largely from plants. The Se concentration in edible plants is determined by the Se phytoavailability in soils. Selenium is not an essential element for plants, but excessive Se can be toxic. Thus, soil Se phytoavailability determines the ecology of plants. Most plants cannot grow on seleniferous soils. Most plants that grow on seleniferous soils accumulate plant species have evolved tolerance to Se, and commonly accumulate tissue Se concentrations >100 mg Se kg(-1) dry matter. These plants are considered to be Se accumulators. Some species can even accumulate Se concentrations of 1000-15 000 mg Se kg(-1 )dry matter and are called Se hyperaccumulators. This article provides an overview of Se uptake, translocation and metabolism in plants and highlights the possible genetic basis of differences in these between and within plant species. The review focuses initially on adaptations allowing plants to tolerate large Se concentrations in their tissues and the evolutionary origin of species that hyperaccumulate Se. It then describes the variation in tissue Se concentrations between and within angiosperm species and identifies genes encoding enzymes limiting the rates of incorporation of Se into organic compounds and chromosomal loci that might enable the development of crops with greater Se concentrations in their edible portions. Finally, it discusses transgenic approaches enabling plants to tolerate greater Se concentrations in the rhizosphere and in their tissues. The trait of Se hyperaccumulation has evolved several times in separate angiosperm clades. The ability to tolerate large tissue Se concentrations is primarily related to the ability to divert Se away from the accumulation of selenocysteine and selenomethionine, which might be incorporated into non-functional proteins, through the synthesis of less toxic Se metabilites. There is potential to breed or select crops

  3. Radiation hormesis in plant

    International Nuclear Information System (INIS)

    Kim, Jae Sung; Song, Hi Sup; Lee, Young Keun; Lee, Byung Hun; Shin, In Chul; Lim, Young Taek

    2000-04-01

    This research was performed to investigate the effects of low dose γ-ray radiation on the seed germination and the following physiological responses in vegetable crops. Special attention was focused on whether the resistance of vegetables against the unfavorable conditions of environment such as subsequent high doses of radiation or Phytophthora blight of pepper could be enhanced as an aspect of radiation hormesis. Analysis and characterization of antioxidant enzyme from plant culture cells and radiation tolerant of transformed plants from antioxidant (POD) were accomplished in the plant irradiated with different dose of γ-ray. (author)

  4. Nuclear power plants maintenance

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    Nuclear power plants maintenance now appears as an important factor contributing to the competitivity of nuclea energy. The articles published in this issue describe the way maintenance has been organized in France and how it led to an actual industrial activity developing and providing products and services. An information note about Georges Besse uranium enrichment plant (Eurodif) recalls that maintenance has become a main data not only for power plants but for all nuclear industry installations. (The second part of this dossier will be published in the next issue: vol. 1 January-February 1989) [fr

  5. Optofluidics of plants

    Directory of Open Access Journals (Sweden)

    Demetri Psaltis

    2016-05-01

    Full Text Available Optofluidics is a tool for synthesizing optical systems, making use of the interaction of light with fluids. In this paper we explore optofluidic mechanisms that have evolved in plants where sunlight and fluidic control combine to define most of the functionality of the plan. We hope that the presentation of how plants function, from an optofluidics point of view, will open a window for the optics community to the vast literature of plant physiology and provide inspiration for new ideas for the design of bio-mimetic optofluidic devices.

  6. Competitive breeder power plants

    International Nuclear Information System (INIS)

    Winkleblack, R.K.

    1984-01-01

    To utilize the fissile material that is accumulating in the utilities' spent fuel pools, breeder plants must be less expensive than current LWR costs (or utilities will not buy nuclear plants in the near future) and also be highly reliable. The fundamental differences between LWRs and LMFBRs are discussed and recommendations are made for making the most of these differences to design a superior breeder plant that can sell in the future, opening the way to U.S. utilities becoming self-sufficient for fuel supply for centuries

  7. Radiation hormesis in plant

    International Nuclear Information System (INIS)

    Kim, Jae Sung; Song, Hi Sup; Lee, Young Keun; Cun, Ki Jung; Shin, In Chul; Lim, Young Taek

    1999-04-01

    This research was performed to investigate the effects of low dose γ-ray radiation on the seed germination and the following physiological responses in vegetable crops. Special attention was focused on whether the resistance of vegetables against the unfavorable conditions of environment such as acid rain or soil types could be enhanced as an aspect of radiation hormesis. Analysis and characterization of antioxidant enzyme from plant culture cells and radiation tolerant of transformed plants from antioxidant enzyme (POD) were accomplished in the plant irradiated with difference dosage of γ-ray

  8. Coal gasification plant

    Energy Technology Data Exchange (ETDEWEB)

    1977-09-29

    The proposal concerns a stage in the process of cooling the synthetic gas produced in a coal gasification plant at temperatures above 900/sup 0/C. The purpose is to keep the convection heating surface of the subsequent waste heat plant free of dirt. According to the invention, the waste heat plant has a radiation area connected before it, on the heating surfaces of which the slack carried over solidifies. This radiation area has a hydraulic and thermal cleaning system, which can be raised or lowered in a water bath. The subclaims concern all the constructional characteristics of this cleaning system, which causes the solidified slack to crack.

  9. TOR signalling in plants.

    Science.gov (United States)

    Rexin, Daniel; Meyer, Christian; Robaglia, Christophe; Veit, Bruce

    2015-08-15

    Although the eukaryotic TOR (target of rapamycin) kinase signalling pathway has emerged as a key player for integrating nutrient-, energy- and stress-related cues with growth and metabolic outputs, relatively little is known of how this ancient regulatory mechanism has been adapted in higher plants. Drawing comparisons with the substantial knowledge base around TOR kinase signalling in fungal and animal systems, functional aspects of this pathway in plants are reviewed. Both conserved and divergent elements are discussed in relation to unique aspects associated with an autotrophic mode of nutrition and adaptive strategies for multicellular development exhibited by plants. © 2015 Authors; published by Portland Press Limited.

  10. Radiation hormesis in plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Sung; Song, Hi Sup; Lee, Young Keun; Cun, Ki Jung; Shin, In Chul; Lim, Young Taek

    1999-04-01

    This research was performed to investigate the effects of low dose {gamma}-ray radiation on the seed germination and the following physiological responses in vegetable crops. Special attention was focused on whether the resistance of vegetables against the unfavorable conditions of environment such as acid rain or soil types could be enhanced as an aspect of radiation hormesis. Analysis and characterization of antioxidant enzyme from plant culture cells and radiation tolerant of transformed plants from antioxidant enzyme (POD) were accomplished in the plant irradiated with difference dosage of {gamma}-ray.

  11. Nuclear power plant outages

    International Nuclear Information System (INIS)

    1998-01-01

    The Finnish Radiation and Nuclear Safety Authority (STUK) controls nuclear power plant safety in Finland. In addition to controlling the design, construction and operation of nuclear power plants, STUK also controls refuelling and repair outages at the plants. According to section 9 of the Nuclear Energy Act (990/87), it shall be the licence-holder's obligation to ensure the safety of the use of nuclear energy. Requirements applicable to the licence-holder as regards the assurance of outage safety are presented in this guide. STUK's regulatory control activities pertaining to outages are also described

  12. FRIB Cryogenic Plant Status

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Kelly D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Ganni, Venkatarao [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Knudsen, Peter N. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Casagranda, Fabio [Michigan State Univ., East Lansing, MI (United States)

    2015-12-01

    After practical changes were approved to the initial conceptual design of the cryogenic system for MSU FRIB and an agreement was made with JLab in 2012 to lead the design effort of the cryogenic plant, many activities are in place leading toward a cool-down of the linacs prior to 2018. This is mostly due to using similar equipment used at CHLII for the 12 GeV upgrade at JLab and an aggressive schedule maintained by the MSU Conventional Facilities department. Reported here is an updated status of the cryogenic plant, including the equipment procurement status, plant layout, facility equipment and project schedule.

  13. Plant-soil feedbacks: role of plant functional group and plant traits

    NARCIS (Netherlands)

    Cortois, R.; Schröder-Georgi, T.; Weigelt, A.; van der Putten, W.H.; De Deyn, G.B.

    2016-01-01

    Plant-soil feedback (PSF), plant trait and functional group concepts advanced our understanding of plant community dynamics, but how they are interlinked is poorly known. To test how plant functional groups (FGs: graminoids, small herbs, tall herbs, legumes) and plant traits relate to PSF, we grew

  14. Plant Growth Promoting Rhizobacteria

    Indian Academy of Sciences (India)

    IAS Admin

    known to improve plant growth in many ways when compared to ... roles in agricultural productivity. ... Sustainable agriculture: Sustainable agriculture involves the successful management of agricultural re- ... For the first time Kloepper et al.

  15. KWU Nuclear Plant Analyzer

    International Nuclear Information System (INIS)

    Bennewitz, F.; Hummel, R.; Oelmann, K.

    1986-01-01

    The KWU Nuclear Plant Analyzer is a real time engineering simulator based on the KWU computer programs used in plant transient analysis and licensing. The primary goal is to promote the understanding of the technical and physical processes of a nuclear power plant at an on-site training facility. Thus the KWU Nuclear Plant Analyzer is available with comparable low costs right at the time when technical questions or training needs arise. This has been achieved by (1) application of the transient code NLOOP; (2) unrestricted operator interaction including all simulator functions; (3) using the mainframe computer Control Data Cyber 176 in the KWU computing center; (4) four color graphic displays controlled by a dedicated graphic computer, no control room equipment; and (5) coupling of computers by telecommunication via telephone

  16. Nuclear Power Plants (Rev.)

    Energy Technology Data Exchange (ETDEWEB)

    Lyerly, Ray L.; Mitchell III, Walter [Southern Nuclear Engineering, Inc.

    1973-01-01

    Projected energy requirements for the future suggest that we must employ atomic energy to generate electric power or face depletion of our fossil-fuel resources—coal, oil, and gas. In short, both conservation and economic considerations will require us to use nuclear energy to generate the electricity that supports our civilization. Until we reach the time when nuclear power plants are as common as fossil-fueled or hydroelectric plants, many people will wonder how the nuclear plants work, how much they cost, where they are located, and what kinds of reactors they use. The purpose of this booklet is to answer these questions. In doing so, it will consider only central station plants, which are those that provide electric power for established utility systems.

  17. Ferrous Metal Processing Plants

    Data.gov (United States)

    Department of Homeland Security — This map layer includes ferrous metal processing plants in the United States. The data represent commodities covered by the Minerals Information Team (MIT) of the...

  18. Nonferrous Metal Processing Plants

    Data.gov (United States)

    Department of Homeland Security — This map layer includes nonferrous metal processing plants in the United States. The data represent commodities covered by the Minerals Information Team (MIT) of the...

  19. Plutonium Finishing Plant

    Data.gov (United States)

    Federal Laboratory Consortium — The Plutonium Finishing Plant, also known as PFP, represented the end of the line (the final procedure) associated with plutonium production at Hanford.PFP was also...

  20. Plant Vascular Biology 2010

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Biao

    2014-11-17

    This grant supported the Second International Conference on Plant Vascular Biology (PVB 2010) held July 24-28, 2010 on the campus of Ohio State University, Columbus, Ohio. Biao Ding (Ohio State University; OSU) and David Hannapel (Iowa State University; ISU) served as co-chairs of this conference. Biao Ding served as the local organizer. PVB is defined broadly here to include studies on the biogenesis, structure and function of transport systems in plants, under conditions of normal plant growth and development as well as of plant interactions with pathogens. The transport systems cover broadly the xylem, phloem, plasmodesmata and vascular cell membranes. The PVB concept has emerged in recent years to emphasize the integrative nature of the transport systems and approaches to investigate them.

  1. Bituminization plant Jaslovske Bohunice

    International Nuclear Information System (INIS)

    1999-01-01

    In this leaflet the principle of the bituminization plant for radioactive concentrate (the intermediate liquid radioactive waste generated during the NPP A1, V-1, V-2 operations) solidification used in the Bohunice Radwaste Treatment Centre (BSC RAO) is presented

  2. Plant stem cell niches.

    Science.gov (United States)

    Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

    2012-01-01

    Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.

  3. Biogas plants; Biogasanlagen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Within the KRdL expert meeting at 30th October, 2012 in Bonn (Federal Republic of Germany), the following lectures were held: (1) New requirements on biomass conversion plants based on the Federal Nuisance Control Ordinance (Hans-Peter Ewens); (2) State of the art of the operation of biomass conversion plants (Christina Dornack); (3) Implementation of the regulation VDI 3475 sheet 4 (Markus Helm); (4) Handling of constraints of residents in the licensing procedure as well as during operation (Helmar Hentschke); (5) Explosion protection for biomass conversion plants considering the matters of immission control (Michael Faber); (6) Microbiological and epidemic-hygienic aspects of agricultural biomass conversion plants and their fermentation residues (Werner Philipp); (7) Emissions of climatic relevant gases at the biogas production (Jacqueline Daniel-Gromke); (8) State of the art in the biogas processing (Joachim Krassowski).

  4. Nuclear power plant construction

    International Nuclear Information System (INIS)

    Lima Moreira, Y.M. de.

    1979-01-01

    The legal aspects of nuclear power plant construction in Brazil, derived from governamental political guidelines, are presented. Their evolution, as a consequence of tecnology development is related. (A.L.S.L.) [pt

  5. Nuclear power plant decommissioning

    International Nuclear Information System (INIS)

    Yaziz Yunus

    1986-01-01

    A number of issues have to be taken into account before the introduction of any nuclear power plant in any country. These issues include reactor safety (site and operational), waste disposal and, lastly, the decommissioning of the reactor inself. Because of the radioactive nature of the components, nuclear power plants require a different approach to decommission compared to other plants. Until recently, issues on reactor safety and waste disposal were the main topics discussed. As for reactor decommissioning, the debates have been academic until now. Although reactors have operated for 25 years, decommissioning of retired reactors has simply not been fully planned. But the Shippingport Atomic Power Plant in Pennysylvania, the first large scale power reactor to be retired, is now being decommissioned. The work has rekindled the debate in the light of reality. Outside the United States, decommissioning is also being confronted on a new plane. (author)

  6. Advanced stellarator power plants

    International Nuclear Information System (INIS)

    Miller, R.L.

    1994-01-01

    The stellarator is a class of helical/toroidal magnetic fusion devices. Recent international progress in stellarator power plant conceptual design is reviewed and comparisons in the areas of physics, engineering, and economics are made with recent tokamak design studies

  7. Protoplasts and plant viruses

    International Nuclear Information System (INIS)

    Murakishi, H.; Lesney, M.S.; Carlson, P.

    1984-01-01

    The use of protoplasts in the study of plant viruses has attracted considerable attention since its inception in the late 1960s. This article is an attempt to assess the current status of protoplasts (primarily) and all cell cultures (in some instances) in studies of virus infection, virus replication, cytopathology, cross-protection, virus resistance, and the use of in vitro methods and genetic engineering to recover virus-resistant plants. These areas of study proved difficult to do entirely with whole plants or plant parts. However, because protoplasts could be synchronously infected with virus, they provided a valuable alternative means of following biochemical and cytological events in relation to the virus growth cycle in a more precise manner than previously possible

  8. Fertilization in Flowering Plants

    Indian Academy of Sciences (India)

    Ecology and the. Environment ... agents (pollinators), the next step before fertilization is to se- .... the embryo sac are referred to as pollen-pistil interaction and play ..... evolutionary success of flowering plants when compared to other groups of ...

  9. Competition between herbage plants

    NARCIS (Netherlands)

    Wit, de C.T.; Bergh, van den J.P.

    1965-01-01

    Starting from work with annuals a model of competition between herbage plants is discussed. It is shown that their mutual interference can only be described adequately if they are grown in mixture and also in monoculture

  10. Photomorphogenesis in plants

    National Research Council Canada - National Science Library

    Kendrick, Richard E; Kronenberg, G. H. M

    1994-01-01

    ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ... VII VIII XXXI Part 1 Introduction 1. Introduction by Lars Olof Bjorn 1.1 1.2 1.3 1.4 1.5 1.6 A developing research field ... Plant vision...

  11. Reprocessing plants safety

    International Nuclear Information System (INIS)

    Davies, A.G.; Leighton, C.; Millington, D.

    1989-01-01

    The reprocessing of irradiated nuclear fuel at British Nuclear Fuels (BNFL) Sellafield site consists of a number of relatively self-contained activities carried out in separate plants across the site. The physical conditions and time scales applied in reprocessing and storage make it relatively benign. The potential for minor releases of radioactivity under fault conditioning is minimised by plant design definition of control procedures, training and supervision. The risks to both the general public and workforce are shown to be low with all the safety criteria being met. Normal operating conditions also have the potential for some occupational radiation exposure and the plant and workers are monitored continuously. Exposure levels have been reduced steadily and will continue to fall with plant improvements. (U.K.)

  12. International power plant business

    Energy Technology Data Exchange (ETDEWEB)

    Grohe, R.

    1986-03-03

    At the Brown Boveri press seminar 'Energy' in Baden-Baden Rainer Grohe, member of the Brown Boveri board, Mannheim, gave a survey of the activities on the international power plant market in recent years. He showed the vacuities which must be taken into account in this sector today. The drastic escalation of demands on power plant suppliers has lead not to a reduction of protagonists but to an increase. (orig.).

  13. Wind power plant

    Energy Technology Data Exchange (ETDEWEB)

    Caneghem, A.E. von

    1975-07-24

    The invention applies to a wind power plant in which the wind is used to drive windmills. The plant consists basically of a vertical tube with a lateral wind entrance opening with windmill on its lower end. On its upper end, the tube carries a nozzle-like top which increases the wind entering the tube by pressure decrease. The wind is thus made suitable for higher outputs. The invention is illustrated by constructional examples.

  14. Janata biogas plant

    Energy Technology Data Exchange (ETDEWEB)

    Bahadur, S; Singh, K K

    1980-03-01

    The Janata biogas plant is based on the use of local materials and locally available skills only. It is a proven technology at low cost and easy maintenance which should facilitate its extension at a much faster pace especially among the low income groups. This technology is important at this time because of the current crisis in the availability of firewood and mineral fuels. This handbook explains in non-technical language the basic features, design, and construction of this biogas plant. (DC)

  15. The plant mitochondrial proteome

    DEFF Research Database (Denmark)

    Millar, A.H.; Heazlewood, J.L.; Kristensen, B.K.

    2005-01-01

    The plant mitochondrial proteome might contain as many as 2000-3000 different gene products, each of which might undergo post-translational modification. Recent studies using analytical methods, such as one-, two- and three-dimensional gel electrophoresis and one- and two-dimensional liquid...... context to be defined for them. There are indications that some of these proteins add novel activities to mitochondrial protein complexes in plants....

  16. NMR, water and plants

    International Nuclear Information System (INIS)

    As, H. van.

    1982-01-01

    This thesis describes the application of a non-destructive pulsed proton NMR method mainly to measure water transport in the xylem vessels of plant stems and in some model systems. The results are equally well applicable to liquid flow in other biological objects than plants, e.g. flow of blood and other body fluids in human and animals. The method is based on a pulse sequence of equidistant π pulses in combination with a linear magnetic field gradient. (Auth.)

  17. Plant Formate Dehydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    John Markwell

    2005-01-10

    The research in this study identified formate dehydrogenase, an enzyme that plays a metabolic role on the periphery of one-carbon metabolism, has an unusual localization in Arabidopsis thaliana and that the enzyme has an unusual kinetic plasticity. These properties make it possible that this enzyme could be engineered to attempt to engineer plants with an improved photosynthetic efficiency. We have produced transgenic Arabidopsis and tobacco plants with increased expression of the formate dehydrogenase enzyme to initiate further studies.

  18. Detergent zeolite filtration plant

    OpenAIRE

    Stanković Mirjana S.; Pezo Lato L.

    2003-01-01

    The IGPC Engineering Department designed basic projects for detergent zeolite filtration plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant with a capacity of 75,000 t/y was manufactured, at "Zeolite Mira", Mira (VE), Italy, in 1997, for increasing detergent zeolite production, from 50,000 to 100,000 t/y. The main goal was to increase the detergent zeoli...

  19. Plant extracts as radioprotectors

    Energy Technology Data Exchange (ETDEWEB)

    Baydoun, S; Al-Oudat, M [Atomic Energy Commission, Department of Radiation Protection and Nuclear Safety, Damascus (Syrian Arab Republic); Al-Achkar, W [Atomic Energy Commission, Department of Radiobiology and Health, Damascus (Syrian Arab Republic)

    1996-09-01

    Several studies show that the extracts of some plants, namely containing vitamins or sulfide components, have radioprotection properties against the effects of ionizing radiation. In Syria, many of hates plants are available. This experiment was conducted in order to test the ability of ten different plants to protect against the radiation damages. These plants are Daucus carota L., Brassica oleracea L, Aloe vera L., Opuntia ficus-indica, Allium cepa L., Capsicum annuum L., Scilla maritima L., Allium sativum L., Rubus sanctus L. and Rosa canina L.Their effects on the protection of E. Coli growth after the exposure to L.D 50 of gamma radiation (100 Gy) were investigated . Two concentrations to each plant extract were tested, both were than 1%. Our results are indicating that the protection depend on plant. The radioprotection factors were ranged between 1.42 to 2.39. The best results were obtained by using the extract of Allium sativum L. (2.01), Opuntia ficus-indica (2.14) and Capsiucum annuum L. (2.39). (author) 16 refs., 2 tabs., 4 figs.

  20. Medicinal plants of Lorestan

    Directory of Open Access Journals (Sweden)

    shahla ahmadi

    2010-03-01

    Full Text Available Collection and determination of medicinal plants in Lorestan province have been carried out for 6 years in the agriculture and natural resources research of center of Lorestan. The aims of this study were collection and identification the medicinal plans that grow in Loretta province, their distribution, habitat, traditional uses, utilized organ, manner of usage, botany specification, local name, Persian name and scientific name. Material and methods: Medicinal plants were collected from different regions by using field and library study for these goals we prepared a list of recorded medicinal plants from Lorestan, identified the local herbal experts. Results: Finally we collected 151 medicinal plant identified that related to 63 families and 90 genuses. The Lamiaceae, Compositae, Legominosae , Liliaceae, Umbelliferae and . Rosaceae are the greatest family in the Lorestan province. Diction: According to the literature 96 medicinal plans were recorded from Lorestan, but during this study we collected and identified 151 medicinal plants in Lorestan province. Comparing with those that recorded from Bushehr 70 sp.(9, Hormozgan 113 sp.(10, Markazi 144 sp. And Kordestan 144 sp(11. We have more diversity but comparing with Zanjan 163 sp.(13, Hamedan 315 sp.(14 And Qazvin 250 sp.(15 We have less diversity in medicinal plants.

  1. Plant extracts as radioprotectors

    International Nuclear Information System (INIS)

    Baydoun, S.; Al-Oudat, M.; Al-Achkar, W.

    1996-09-01

    Several studies show that the extracts of some plants, namely containing vitamins or sulfide components, have radioprotection properties against the effects of ionizing radiation. In Syria, many of hates plants are available. This experiment was conducted in order to test the ability of ten different plants to protect against the radiation damages. These plants are Daucus carota L., Brassica oleracea L, Aloe vera L., Opuntia ficus-indica, Allium cepa L., Capsicum annuum L., Scilla maritima L., Allium sativum L., Rubus sanctus L. and Rosa canina L.Their effects on the protection of E. Coli growth after the exposure to L.D 50 of gamma radiation (100 Gy) were investigated . Two concentrations to each plant extract were tested, both were than 1%. Our results are indicating that the protection depend on plant. The radioprotection factors were ranged between 1.42 to 2.39. The best results were obtained by using the extract of Allium sativum L. (2.01), Opuntia ficus-indica (2.14) and Capsiucum annuum L. (2.39). (author) 16 refs., 2 tabs., 4 figs

  2. Plant extracts as radioprotectors

    International Nuclear Information System (INIS)

    Baydoun, S.; Al-Oudat, M.; Al-Achkar, W.

    1997-01-01

    Several studies show that the extracts of some plants, namely containing vitamins or sulfide components, have radioprotection properties against the effects of ionizing radiation. In Syria, many of hates plants are available. This experiment was conducted in order to test the ability of ten different plants to protect against the radiation damages. These plants are Daucus carota L., Brassica oleracea L, Aloe vera L., Opuntia ficus-indica, Allium cepa L., Capsicum annuum L., Scilla maritima L., Allium sativum L., Rubus sanctus L. and Rosa canina L.Their effects on the protection of E. Coli growth after the exposure to L.D 50 of gamma radiation (100 Gy) were investigated . Two concentrations to each plant extract were tested, both were than 1%. Our results are indicating that the protection depend on plant. The radioprotection factors were ranged between 1.42 to 2.39. The best results were obtained by using the extract of Allium sativum L. (2.01), Opuntia ficus-indica (2.14) and Capsiucum annuum L. (2.39). (author)

  3. Power plants 2010. Lectures

    International Nuclear Information System (INIS)

    2010-01-01

    The proceedings include the following lectures: Facing the challenges - new structures for electricity production. Renewable energies in Europe - chances and challenges. Nuclear outlook in the UK. Sustainable energy for Europe. Requirements of the market and the grid operator at the electricity production companies. Perspectives for the future energy production. Pumped storage plants - status and perspectives. Nuclear power/renewable energies -partners or opponents? New fossil fired power stations in Europe - status and perspectives. Nuclear energy: outlook for new build and lifetime extension in Europe. Biomass in the future European energy market - experiences for dong energy. Meeting the EU 20:20 renewable energy targets: the offshore challenges. DESERTEC: sustainable electricity for Europe, Middle East and North Africa. New power plants in Europe - a challenge for project and quality management. Consideration of safely in new build activities of power plants. Challenges to an integrated development in Maasvlakte, Netherlands. Power enhancement in EnBW power plants. Operational experiences of CCS pilot plants worldwide. Two years of operational experiences with Vattenfall's oxyfuel pilot plant. Pre-conditions for CCS. Storage technologies for a volatile generation. Overview: new generation of gas turbines.

  4. Plant monitoring device

    International Nuclear Information System (INIS)

    Ito, Toru.

    1994-01-01

    The device of the present invention comprises a data collecting section for periodically collecting processed data sent from plant equipments, a top node induction and processing section for an important plant function model for inducing the plant function to be noted particularly by an operator from important plant function models by using process data and a window screen selection section for selecting a window screen to be displayed based on the result of the evaluation for each of function nodes based on the processing described above and determining the layout and automatically forming the display screen. It is constituted so that the kind and the layout of the window under display are checked if they are the same as those one cycle before or not and, if they are different, the screen is automatically switched to a new screen display. Then, operator's psychological burdens such as selection of information and judgement for the operation upon occurrence of plant abnormality and accident can be mitigated, to provide a safe operation circumstance having reinforced monitoring of the function of the whole plant can be provided. (N.H.)

  5. Uranium speciation in plants

    International Nuclear Information System (INIS)

    Guenther, A.; Bernhard, G.; Geipel, G.; Reich, T.; Rossberg, A.; Nitsche, H.

    2003-01-01

    Detailed knowledge of the nature of uranium complexes formed after the uptake by plants is an essential prerequisite to describe the migration behavior of uranium in the environment. This study focuses on the determination of uranium speciation after uptake of uranium by lupine plants. For the first time, time-resolved laser-induced fluorescence spectroscopy and X-ray absorption spectroscopy were used to determine the chemical speciation of uranium in plants. Differences were detected between the uranium speciation in the initial solution (hydroponic solution and pore water of soil) and inside the lupine plants. The oxidation state of uranium did not change and remained hexavalent after it was taken up by the lupine plants. The chemical speciation of uranium was identical in the roots, shoot axis, and leaves and was independent of the uranium speciation in the uptake solution. The results indicate that the uranium is predominantly bound as uranyl(VI) phosphate to the phosphoryl groups. Dandelions and lamb's lettuce showed uranium speciation identical to lupine plants. (orig.)

  6. Plant critical concept

    International Nuclear Information System (INIS)

    O'Regan, P.J.

    1996-01-01

    The objective of the effort summarized in this paper is to support O and M cost reduction efforts by focusing resources on components and processes critical to plant performance. This effort will identify where resources on nonplant critical components and processes can be reduced or eliminated. This method will use a functional assessment as the basis for component-specific evaluations and ranking. This effort consists of two stages conducted in series. The first stage is to deterministically identify that set of plant components that are relevant from a plant performance perspective (i.e., safety, economics, reliability). The second stage probabilistically ranks that set of plant components from an importance perspective, where importance pertains to the particular application and is probabilistically weighted. The results of a pilot study identified that only a relatively small set of components are truly critical from an integrated plant performance perspective. These results are consistent with work being conducted at other nuclear power plants, as well as other commercial facilities. Initial implementation of this effort is estimated to reduce O and M costs on the order of $1 million per year. Subsequent applications are anticipated to increase that savings to $4--$5 million per year

  7. Landscaping plant epigenetics.

    Science.gov (United States)

    McKeown, Peter C; Spillane, Charles

    2014-01-01

    The understanding of epigenetic mechanisms is necessary for assessing the potential impacts of epigenetics on plant growth, development and reproduction, and ultimately for the response of these factors to evolutionary pressures and crop breeding programs. This volume highlights the latest in laboratory and bioinformatic techniques used for the investigation of epigenetic phenomena in plants. Such techniques now allow genome-wide analyses of epigenetic regulation and help to advance our understanding of how epigenetic regulatory mechanisms affect cellular and genome function. To set the scene, we begin with a short background of how the field of epigenetics has evolved, with a particular focus on plant epigenetics. We consider what has historically been understood by the term "epigenetics" before turning to the advances in biochemistry, molecular biology, and genetics which have led to current-day definitions of the term. Following this, we pay attention to key discoveries in the field of epigenetics that have emerged from the study of unusual and enigmatic phenomena in plants. Many of these phenomena have involved cases of non-Mendelian inheritance and have often been dismissed as mere curiosities prior to the elucidation of their molecular mechanisms. In the penultimate section, consideration is given to how advances in molecular techniques are opening the doors to a more comprehensive understanding of epigenetic phenomena in plants. We conclude by assessing some opportunities, challenges, and techniques for epigenetic research in both model and non-model plants, in particular for advancing understanding of the regulation of genome function by epigenetic mechanisms.

  8. Plant monitoring device

    International Nuclear Information System (INIS)

    Moriyama, Kunio.

    1991-01-01

    The monitoring device of the present invention is most suitable to early detection for equipment abnormality, or monitoring of state upon transient conditions such as startup and shutdown of an electric power plant, a large-scaled thermonuclear device and an accelerator plant. That is, in existent moitoring devices, acquired data are stored and the present operation states are monitored in comparison. A plant operation aquisition data reproduction section is disposed to the device. From the past operation conditions stored in the plant operation data aquisition reproducing section, the number of operation cycles that agrees with the present plant operation conditions is sought, to determine the agreed aquired data. Since these aquired data are time sequential data measured based on the standard time determined by the operation sequence, aquired data can be reproduced successively on every sample pitches. With such a constitution, aquired data under the same operation conditions as the present conditions are displayed together with the measured data. Accordingly, accurate monitoring can be conducted from the start-up to the shutdown of the plant. (I.S.)

  9. Molecular plant volatile communication.

    Science.gov (United States)

    Holopainen, Jarmo K; Blande, James D

    2012-01-01

    Plants produce a wide array of volatile organic compounds (VOCs) which have multiple functions as internal plant hormones (e.g., ethylene, methyl jasmonate and methyl salicylate), in communication with conspecific and heterospecific plants and in communication with organisms of second (herbivores and pollinators) and third (enemies of herbivores) trophic levels. Species specific VOCs normally repel polyphagous herbivores and those specialised on other plant species, but may attract specialist herbivores and their natural enemies, which use VOCs as host location cues. Attraction of predators and parasitoids by VOCs is considered an evolved indirect defence, whereby plants are able to indirectly reduce biotic stress caused by damaging herbivores. In this chapter we review these interactions where VOCs are known to play a crucial role. We then discuss the importance of volatile communication in self and nonself detection. VOCs are suggested to appear in soil ecosystems where distinction of own roots from neighbours roots is essential to optimise root growth, but limited evidence of above-ground plant self-recognition is available.

  10. Conservation law of plants' energy value dependence of plants ...

    African Journals Online (AJOL)

    The plants differences in biochemical composition are analyzed, and the conservation law of energy value in plants is obtained. The link between the need for the nutrients and the plants biochemical composition is examined, Liebig's law is specified. Keywords: plant's biochemical composition, biochemistry, energy value in ...

  11. Chapter 15. Plant pathology and managing wildland plant disease systems

    Science.gov (United States)

    David L. Nelson

    2004-01-01

    Obtaining specific, reliable knowledge on plant diseases is essential in wildland shrub resource management. However, plant disease is one of the most neglected areas of wildland resources experimental research. This section is a discussion of plant pathology and how to use it in managing plant disease systems.

  12. Chemical signaling between plants and plant-pathogenic bacteria.

    Science.gov (United States)

    Venturi, Vittorio; Fuqua, Clay

    2013-01-01

    Studies of chemical signaling between plants and bacteria in the past have been largely confined to two models: the rhizobial-legume symbiotic association and pathogenesis between agrobacteria and their host plants. Recent studies are beginning to provide evidence that many plant-associated bacteria undergo chemical signaling with the plant host via low-molecular-weight compounds. Plant-produced compounds interact with bacterial regulatory proteins that then affect gene expression. Similarly, bacterial quorum-sensing signals result in a range of functional responses in plants. This review attempts to highlight current knowledge in chemical signaling that takes place between pathogenic bacteria and plants. This chemical communication between plant and bacteria, also referred to as interkingdom signaling, will likely become a major research field in the future, as it allows the design of specific strategies to create plants that are resistant to plant pathogens.

  13. Plants in alpine environments

    Science.gov (United States)

    Germino, Matthew J.

    2014-01-01

    Alpine and subalpine plant species are of special interest in ecology and ecophysiology because they represent life at the climate limit and changes in their relative abundances can be a bellwether for climate-change impacts. Perennial life forms dominate alpine plant communities, and their form and function reflect various avoidance, tolerance, or resistance strategies to interactions of cold temperature, radiation, wind, and desiccation stresses that prevail in the short growing seasons common (but not ubiquitous) in alpine areas. Plant microclimate is typically uncoupled from the harsh climate of the alpine, often leading to substantially warmer plant temperatures than air temperatures recorded by weather stations. Low atmospheric pressure is the most pervasive, fundamental, and unifying factor for alpine environments, but the resulting decrease in partial pressure of CO2 does not significantly limit carbon gain by alpine plants. Factors such as tree islands and topographic features create strong heterogeneous mosaics of microclimate and snow cover that are reflected in plant community composition. Factors affecting tree establishment and growth and formation of treeline are key to understanding alpine ecology. Carbohydrate and other carbon storage, rapid development in a short growing season, and physiological function at low temperature are prevailing attributes of alpine plants. A major contemporary research theme asks whether chilling at alpine-treeline affects the ability of trees to assimilate the growth resources and particularly carbon needed for growth or whether the growth itself is limited by the alpine environment. Alpine areas tend to be among the best conserved, globally, yet they are increasingly showing response to a range of anthropogenic impacts, such as atmospheric deposition.

  14. Advanced plant design recommendations from Cook Nuclear Plant experience

    International Nuclear Information System (INIS)

    Zimmerman, W.L.

    1993-01-01

    A project in the American Electric Power Service Corporation to review operating and maintenance experience at Cook Nuclear Plant to identify recommendations for advanced nuclear plant design is described. Recommendations so gathered in the areas of plant fluid systems, instrument and control, testing and surveillance provisions, plant layout of equipment, provisions to enhance effective maintenance, ventilation systems, radiological protection, and construction, are presented accordingly. An example for a design review checklist for effective plant operations and maintenance is suggested

  15. Japanese national reference reprocessing plant

    International Nuclear Information System (INIS)

    1978-08-01

    This paper gives a general description of the proposed Japanese national reprocessing plant and of the design philosophy. The plant is in most respects similar to the base case reprocessing plant, with an annual throughput of 100-1500 tU. The plant would be co-located with a fuel fabrication facility

  16. African names for American plants

    NARCIS (Netherlands)

    Andel, van T.R.

    2015-01-01

    African slaves brought plant knowledge to the New World, sometimes applying it to related plants they found there and sometimes bringing Old World plants with them. By tracing the linguistic parallels between names for plants in African languages and in communities descended from African slaves,

  17. Cadmium uptake by plants

    Energy Technology Data Exchange (ETDEWEB)

    Haghiri, F.

    1973-01-01

    Absorption of /sup 115m/Cd by soybean (Gylcine max l.) plants via foliar and root systems and translocation into the seed was determined. The uptake of /sup 115m/Cd by soybeans via the root system was more efficient than that of the foliar placement. Growth and Cd concentrations of soybean and wheat (Triticum aestivum l.) tops were influenced by soil-applied Cd. In both crops, the Cd concentration of plant tops increased while yield decreased with increasing levels of applied Cd. Cadmium toxicitiy began to occur in both crops at the lowest level of soil applied Cd (2.5 ppM). With soybean plants, Cd toxicity symptoms resembled fe chlorosis. For wheat plants there were no visual symptoms other than the studied growth. The relative concentration of Cd found in several vegetable crops varied depending on the plant species. The relative Cd concentration in descending order for various vegetables was lettuce (Lactuca sativa l.) > radish top (Raphanus sativus l.) > celery stalk (Apium graveolens l.) > celery leaves greater than or equal to green pepper (Capsicum frutescens l.) > radish roots.

  18. Plant critical concept

    International Nuclear Information System (INIS)

    O'Regan, P.J.

    1995-01-01

    The achievement of operation and maintenance (O ampersand M) cost reductions is a prime concern for plant operators. Initiatives by the nuclear industry to address this concern are under way and/or in development. These efforts include plant reliability studies, reliability-centered maintenance, risk ranking and testing philosophies, performance-based testing philosophies, graded quality assurance, and so forth. This paper presents the results of an effort to develop a methodology that integrates and applies the common data and analysis requirements for a number of risk-based and performance-based initiatives. This initial phase of the effort applied the methodology and its results to two initiatives. These were the procurement function and the preventive maintenance function. This effort integrated multiple programs and functions to identify those components that are truly critical from an integrated plant performance perspective. The paper describes the scope of the effort, the development of a methodology to identify plant critical components, and the application of these results to the maintenance rule compliance, preventive maintenance, and procurement functions at the candidate plant

  19. Benchmarking Nuclear Power Plants

    International Nuclear Information System (INIS)

    Jakic, I.

    2016-01-01

    One of the main tasks an owner have is to keep its business competitive on the market while delivering its product. Being owner of nuclear power plant bear the same (or even more complex and stern) responsibility due to safety risks and costs. In the past, nuclear power plant managements could (partly) ignore profit or it was simply expected and to some degree assured through the various regulatory processes governing electricity rate design. It is obvious now that, with the deregulation, utility privatization and competitive electricity market, key measure of success used at nuclear power plants must include traditional metrics of successful business (return on investment, earnings and revenue generation) as well as those of plant performance, safety and reliability. In order to analyze business performance of (specific) nuclear power plant, benchmarking, as one of the well-established concept and usual method was used. Domain was conservatively designed, with well-adjusted framework, but results have still limited application due to many differences, gaps and uncertainties. (author).

  20. Ornamental Plant Breeding

    Directory of Open Access Journals (Sweden)

    Flávia Barbosa Silva Botelho

    2015-04-01

    Full Text Available World’s ornamental plant market, including domestic market of several countries and its exports, is currently evaluated in 107 billion dollars yearly. Such estimate highlights the importance of the sector in the economy of the countries, as well as its important social role, as it represents one of the main activities, which contributes to income and employment. Therefore a well-structured plant breeding program, which is connected with consumers’ demands, is required in order to fulfill these market needs globally. Activities related to pre-breeding, conventional breeding, and breeding by biotechnological techniques constitute the basis for the successful development of new ornamental plant cultivars. Techniques that involve tissue culture, protoplast fusion and genetic engineering greatly aid conventional breeding (germplasm introduction, plant selection and hybridization, aiming the obtention of superior genotypes. Therefore it makes evident, in the literature, the successful employment of genetic breeding, since it aims to develop plants with commercial value that are also competitive with the ones available in the market.

  1. Plant arginyltransferases (ATEs

    Directory of Open Access Journals (Sweden)

    Tatiana Domitrovic

    Full Text Available Abstract Regulation of protein stability and/or degradation of misfolded and damaged proteins are essential cellular processes. A part of this regulation is mediated by the so-called N-end rule proteolytic pathway, which, in concert with the ubiquitin proteasome system (UPS, drives protein degradation depending on the N-terminal amino acid sequence. One important enzyme involved in this process is arginyl-t-RNA transferase, known as ATE. This enzyme acts post-translationally by introducing an arginine residue at the N-terminus of specific protein targets to signal degradation via the UPS. However, the function of ATEs has only recently begun to be revealed. Nonetheless, the few studies to date investigating ATE activity in plants points to the great importance of the ATE/N-end rule pathway in regulating plant signaling. Plant development, seed germination, leaf morphology and responses to gas signaling in plants are among the processes affected by the ATE/N-end rule pathway. In this review, we present some of the known biological functions of plant ATE proteins, highlighting the need for more in-depth studies on this intriguing pathway.

  2. Soft valves in plants

    Science.gov (United States)

    Park, Keunhwan; Tixier, Aude; Christensen, Anneline; Arnbjerg-Nielsen, Sif; Zwieniecki, Maciej; Jensen, Kaare

    2017-11-01

    Water and minerals flow from plant roots to leaves in the xylem, an interconnected network of vascular conduits that spans the full length of the organism. When a plant is subjected to drought stress, air pockets can spread inside the xylem, threatening the survival of the plant. Many plants prevent propagation of air by using hydrophobic nano-membranes in the ``pit'' pores that link adjacent xylem cells. This adds considerable resistance to flow. Interestingly, torus-margo pit pores in conifers are open and offer less resistance. To prevent propagation of air, conifers use a soft gating mechanism, which relies on hydrodynamic interactions between the xylem liquid and the elastic pit. However, it is unknown exactly how it is able to combine the seemingly antagonist functions of high permeability and resistance to propagation of air. We conduct experiments on biomimetic pores to elucidate the flow regulation mechanism. The design of plant valves is compared to other natural systems and optimal strategies are discussed. This work was supported by a research Grant (13166) from VILLUM FONDEN.

  3. AECL's plant Information Technologies

    International Nuclear Information System (INIS)

    DeVerno, M.; Lupton, L.; Didsbury, R.; Judd, R.

    1998-01-01

    The competitiveness of the world-wide energy market is a continual driving force for improvements to CANDU performance and lower operating, maintenance, and administration costs. As in other industries, advanced Information Technologies (IT) are changing the way we work and conduct business. The nuclear industry is no different and there exists strong incentives to improve work processes and provide faster and more flexible access to the information needed to effectively manage and maintain nuclear plant assets. AECL has responded to these forces through the development of a vision of integrated IT systems addressing all phases of nuclear plant development and operations. This includes the initial engineering, design, and construction processes as well as support to the long-term operations and maintenance. Integral to the AECL vision is the need for cost-effective engineering and operational configuration management systems, proactive maintenance processes and systems, and advanced plant surveillance and diagnostics. This paper presents the vision and describes the integrated information systems needed to manage both the design basis and operating plant data systems to ensure the cost-effective, long-term viability of CANDU plants. (author)

  4. Antidiabetic Plants of Iran

    Directory of Open Access Journals (Sweden)

    Ashrafeddin Goushegir

    2011-10-01

    Full Text Available To identify the antidiabetic plants of Iran, a systematic review of the published literature on the efficacy of Iranian medicinal plant for glucose control in patients with type 2 diabetes mellitus was conducted. We performed an electronic literature search of MEDLINE, Science Direct, Scopus, Proquest, Ebsco, Googlescholar, SID, Cochrane Library Database, from 1966 up to June 2010. The search terms were complementary and alternative medicine (CAM, diabetes mellitus, plant (herb, Iran, patient, glycemic control, clinical trial, RCT, natural or herbal medicine, hypoglycemic plants, and individual herb names from popular sources, or combination of these key words. Available Randomized Controlled Trials (RCT published in English or Persian language examined effects of an herb (limited to Iran on glycemic indexes in type 2 diabetic patients were included. Among all of the articles identified in the initial database search, 23 trials were RCT, examining herbs as potential therapy for type 2 diabetes mellitus. The key outcome for antidiabetic effect was changes in blood glucose or HbA1 c, as well as improves in insulin sensitivity or resistance. Available data suggest that several antidiabetic plants of Iran need further study. Among the RCT studies, the best evidence in glycemic control was found in Citrullus colocynthus, Ipomoea betatas, Silybum marianum and Trigonella foenum graecum.

  5. Geothermal Power Generation Plant

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Tonya [Oregon Inst. of Technology, Klamath Falls, OR (United States). Geo-Heat Center

    2013-12-01

    Oregon Institute of Technology (OIT) drilled a deep geothermal well on campus (to 5,300 feet deep) which produced 196°F resource as part of the 2008 OIT Congressionally Directed Project. OIT will construct a geothermal power plant (estimated at 1.75 MWe gross output). The plant would provide 50 to 75 percent of the electricity demand on campus. Technical support for construction and operations will be provided by OIT’s Geo-Heat Center. The power plant will be housed adjacent to the existing heat exchange building on the south east corner of campus near the existing geothermal production wells used for heating campus. Cooling water will be supplied from the nearby cold water wells to a cooling tower or air cooling may be used, depending upon the type of plant selected. Using the flow obtained from the deep well, not only can energy be generated from the power plant, but the “waste” water will also be used to supplement space heating on campus. A pipeline will be construction from the well to the heat exchanger building, and then a discharge line will be construction around the east and north side of campus for anticipated use of the “waste” water by facilities in an adjacent sustainable energy park. An injection well will need to be drilled to handle the flow, as the campus existing injection wells are limited in capacity.

  6. Pinellas Plant facts

    International Nuclear Information System (INIS)

    1986-09-01

    This plant was built in 1956 in response to a need for the manufacture of neutron generators, a principal component in nuclear weapons. The neutron generators consist of a miniaturized linear ion accelerator assembled with the pulsed electrical power supplies required for its operation. The ion accelerator, or neutron tube, requires ultra clean, high vacuum technology: hermetic seals between glass, ceramic, glass-ceramic, and metal materials: plus high voltage generation and measurement technology. The existence of these capabilities at the Pinellas Plant has led directly to the assignment of the lightning arrester connector, specialty capacitor, vacuum switch, and crystal resonator. Active and reserve batteries and the radioisotopically-powered thermoelectric generator draw on the materials measurement and controls technologies which are required to ensure neutron generator life. A product development and production capability in alumina ceramics, cermet (electrical) feedthroughs, and glass ceramics has become a specialty of the plant; the laboratories monitor the materials and processes used by the plant's commercial suppliers of ferroelectric ceramics. In addition to the manufacturing facility, a production development capability is maintained at the Pinellas Plant

  7. Latina nuclear power plant

    International Nuclear Information System (INIS)

    1976-03-01

    In the period under review, the Latina power plant produced 1009,07 million kWh with a utilization factor of 72% and an availability factor of 80,51%. The disparity between the utilization and availability factors was mainly due to the shutdown of the plant owing to trade union strife. The reasons for non-availability (19,49%) were almost all related to the functioning of the conventional part and the general servicing of the plant (18 September-28 October). During the shutdown for maintenance, an inspection of the steel members and parts of the core stabilizing structure was made in order to check for the familiar oxidation phenomena caused by CO 2 ; the results of the inspection were all satisfactory. Operation of the plant during 1974 was marked by numerous power cutbacks as a result of outages of the steam-raising units (leaks from the manifolds) and main turbines (inspection and repairs to the LP rotors). Since it was first brought into commercial operation, the plant has produced 13,4 thousand million kWh

  8. Plants cultivation in controlled containments

    International Nuclear Information System (INIS)

    2000-01-01

    The plants cultivation in controlled containments permits to the - Departement d'Ecophysiologie Vegetale et de Microbiologie (DVEM) - of the CEA to lead several topics of research. The works of DVEM which are based on the molecular labelling, technique adapted to plants, contribute to understand the plant - soil relationships and the plant growth process. In addition, the staff of DVEM study the impact of pollutant heavy metals, existing in the soil, on plants and the plant stress induced by oxygen, light, ionizing radiations,... and defence mechanisms of plants (F. M.)

  9. Owners of nuclear power plants

    International Nuclear Information System (INIS)

    Wood, R.S.

    1991-07-01

    This report indicates percentage ownership of commercial nuclear power plants by utility companies. The report includes all plants operating, under construction, docketed for NRC safety and environmental reviews, or under NRC antitrust review, but does not include those plants announced but not yet under review or those plants formally cancelled. Part 1 of the report lists plants alphabetically with their associated applicants or licensees and percentage ownership. Part 2 lists applicants or licensees alphabetically with their associated plants and percentage ownership. Part 1 also indicates which plants have received operating licenses (OLS)

  10. PV power plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Within the international seminar of the Ostbayerisches Technologie-Transfer-Institut e.V. (OTTI) at 11th June, 2012 in Munich (Federal Republic of Germany), the following lectures were held: (1) Technical due diligence (Dietmar Obst); (2) Certification / rating system for large PV plants (Robert Pfatischer); (3) O and M requirements (Lars Rulf); (4) IR photography for large scale systems (Bernhard Weinreich); (5) New market models for PV systems - direct marketing and sales of PV electricity (Martin Schneider); (6) Needs and benefits for plant certification for grid connection and operation (Christoph Luetke-Lengerich); (7) Lare volume module testing / Screening in the field and workshop (Semir Merzoug); (8) Dismantling costs of large scale PV plants (Siegfried Schimpf).

  11. Plant redox proteomics

    DEFF Research Database (Denmark)

    Navrot, Nicolas; Finnie, Christine; Svensson, Birte

    2011-01-01

    PTMs in regulating enzymatic activities and controlling biological processes in plants. Notably, proteins controlling the cellular redox state, e.g. thioredoxin and glutaredoxin, appear to play dual roles to maintain oxidative stress resistance and regulate signal transduction pathways via redox PTMs......In common with other aerobic organisms, plants are exposed to reactive oxygen species resulting in formation of post-translational modifications related to protein oxidoreduction (redox PTMs) that may inflict oxidative protein damage. Accumulating evidence also underscores the importance of redox....... To get a comprehensive overview of these types of redox-regulated pathways there is therefore an emerging interest to monitor changes in redox PTMs on a proteome scale. Compared to some other PTMs, e.g. protein phosphorylation, redox PTMs have received less attention in plant proteome analysis, possibly...

  12. Collective biogas plants

    International Nuclear Information System (INIS)

    1992-01-01

    Papers contributed to the European seminar on collective biogas plants held at Herning, Denmark on October 22-23 under the auspices of the Commission of the European Communities, Directorate-General for Energy (DG XVII) are presented. Within the framework of the THERMIE programme, a network of OPETs (Organizations for the Promotion of Energy Technologies) was set up in order to disseminate information on new energy technologies throughout the European communities. The potential for further implementation of centralized capacity for the conversion of animal manures and other organic wastes to bio-fuels, not only in central and eastern Europe but also in the developing countries, is discussed in addition to the relevant technologies. Actual biomass conversion plants are described and details are given on operational experience and plant management. Agricultural, economic and policy aspects are also dealt with. (AB)

  13. Town gas plants

    International Nuclear Information System (INIS)

    Anastos, G.J.; Johnson, G.M.; Schapot, R.M.; Velez, V.G.

    1990-01-01

    Town gas plant sites are receiving increasing attention from the utility industry and regulatory communities. This attention has been prompted by greater environmental awareness of impacts due to past disposal practices and the understanding that gas plant wastes contain a wide range of chemical constituents that have persisted in the environment. This paper discusses the history of the town gas plant industry, the various processes utilized and the resultant by-products and wastes. Potential problem areas relating to these sites as well as potential approaches to site characterization are addressed. Included are recommendations for the phasing of site investigations and the use of relatively inexpensive and rapid field screening techniques to identify contamination

  14. Plant stem cell niches.

    Science.gov (United States)

    Stahl, Yvonne; Simon, Rüdiger

    2005-01-01

    Stem cells are required to support the indeterminate growth style of plants. Meristems are a plants stem cell niches that foster stem cell survival and the production of descendants destined for differentiation. In shoot meristems, stem cell fate is decided at the populational level. The size of the stem cell domain at the meristem tip depends on signals that are exchanged with cells of the organizing centre underneath. In root meristems, individual stem cells are controlled by direct interaction with cells of the quiescent centre that lie in the immediate neighbourhood. Analysis of the interactions and signaling processes in the stem cell niches has delivered some insights into the molecules that are involved and revealed that the two major niches for plant stem cells are more similar than anticipated.

  15. Nuclear plant life extension

    International Nuclear Information System (INIS)

    Negin, C.A.

    1989-01-01

    The nuclear power industry's addressing of life extension is a natural trend in the maturation of this technology after 20 years of commercial operation. With increasing emphasis on how plants are operated, and less on how to build them, attention is turning on to maximizing the use of these substantial investments. The first studies of life extension were conducted in the period from 1978 and 1982. These were motivated by the initiation, by the Nuclear Regulatory Commission (NRC), of studies to support decommissioning rulemaking. The basic conclusions of those early studies that life extension is feasible and worth pursuing have not been changed by the much more extensive investigations that have since been conducted. From an engineering perspective, life extension for nuclear plants is fundamentally the same as for fossil plants

  16. Individual plant examination: Submittal guidance

    International Nuclear Information System (INIS)

    1989-08-01

    Based on a Policy Statement on Severe Accidents Regarding Future Designs and Existing Plants, the performance of a plant examination is requested from the licensee of each nuclear power plant. The plant examination looks for vulnerabilities to severe accidents and cost-effective safety improvements that reduce or eliminate the important vulnerabilities. This document delineates guidance for reporting the results of that plant examination. 38 refs., 2 tabs

  17. Urea metabolism in plants.

    Science.gov (United States)

    Witte, Claus-Peter

    2011-03-01

    Urea is a plant metabolite derived either from root uptake or from catabolism of arginine by arginase. In agriculture, urea is intensively used as a nitrogen fertilizer. Urea nitrogen enters the plant either directly, or in the form of ammonium or nitrate after urea degradation by soil microbes. In recent years various molecular players of plant urea metabolism have been investigated: active and passive urea transporters, the nickel metalloenzyme urease catalyzing the hydrolysis of urea, and three urease accessory proteins involved in the complex activation of urease. The degradation of ureides derived from purine breakdown has long been discussed as a possible additional metabolic source for urea, but an enzymatic route for the complete hydrolysis of ureides without a urea intermediate has recently been described for Arabidopsis thaliana. This review focuses on the proteins involved in plant urea metabolism and the metabolic sources of urea but also addresses open questions regarding plant urea metabolism in a physiological and agricultural context. The contribution of plant urea uptake and metabolism to fertilizer urea usage in crop production is still not investigated although globally more than half of all nitrogen fertilizer is applied to crops in the form of urea. Nitrogen use efficiency in crop production is generally well below 50% resulting in economical losses and creating ecological problems like groundwater pollution and emission of nitric oxides that can damage the ozone layer and function as greenhouse gasses. Biotechnological approaches to improve fertilizer urea usage bear the potential to increase crop nitrogen use efficiency. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  18. Ion channels in plants.

    Science.gov (United States)

    Hedrich, Rainer

    2012-10-01

    Since the first recordings of single potassium channel activities in the plasma membrane of guard cells more than 25 years ago, patch-clamp studies discovered a variety of ion channels in all cell types and plant species under inspection. Their properties differed in a cell type- and cell membrane-dependent manner. Guard cells, for which the existence of plant potassium channels was initially documented, advanced to a versatile model system for studying plant ion channel structure, function, and physiology. Interestingly, one of the first identified potassium-channel genes encoding the Shaker-type channel KAT1 was shown to be highly expressed in guard cells. KAT1-type channels from Arabidopsis thaliana and its homologs from other species were found to encode the K(+)-selective inward rectifiers that had already been recorded in early patch-clamp studies with guard cells. Within the genome era, additional Arabidopsis Shaker-type channels appeared. All nine members of the Arabidopsis Shaker family are localized at the plasma membrane, where they either operate as inward rectifiers, outward rectifiers, weak voltage-dependent channels, or electrically silent, but modulatory subunits. The vacuole membrane, in contrast, harbors a set of two-pore K(+) channels. Just very recently, two plant anion channel families of the SLAC/SLAH and ALMT/QUAC type were identified. SLAC1/SLAH3 and QUAC1 are expressed in guard cells and mediate Slow- and Rapid-type anion currents, respectively, that are involved in volume and turgor regulation. Anion channels in guard cells and other plant cells are key targets within often complex signaling networks. Here, the present knowledge is reviewed for the plant ion channel biology. Special emphasis is drawn to the molecular mechanisms of channel regulation, in the context of model systems and in the light of evolution.

  19. Integrated Gasification SOFC Plant with a Steam Plant

    DEFF Research Database (Denmark)

    Rokni, Masoud; Pierobon, Leonardo

    2011-01-01

    A hybrid Solid Oxide Fuel Cell (SOFC) and Steam Turbine (ST) plant is integrated with a gasification plant. Wood chips are fed to the gasification plant to produce biogas and then this gas is fed into the anode side of a SOFC cycle to produce electricity and heat. The gases from the SOFC stacks...... enter into a burner to burn the rest of the fuel. The offgases after the burner are now used to generate steam in a Heat Recovery Steam Generator (HRSG). The generated steam is expanded in a ST to produce additional power. Thus a triple hybrid plant based on a gasification plant, a SOFC plant...... and a steam plant is presented and studied. The plant is called as IGSS (Integrated Gasification SOFC Steam plant). Different systems layouts are presented and investigated. Electrical efficiencies up to 56% are achieved which is considerably higher than the conventional integrated gasification combined...

  20. Plant biotechnology: transgenic crops.

    Science.gov (United States)

    Shewry, Peter R; Jones, Huw D; Halford, Nigel G

    2008-01-01

    Transgenesis is an important adjunct to classical plant breeding, in that it allows the targeted manipulation of specific characters using genes from a range of sources. The current status of crop transformation is reviewed, including methods of gene transfer, the selection of transformed plants and control of transgene expression. The application of genetic modification technology to specific traits is then discussed, including input traits relating to crop production (herbicide tolerance and resistance to insects, pathogens and abiotic stresses) and output traits relating to the composition and quality of the harvested organs. The latter include improving the nutritional quality for consumers as well as the improvement of functional properties for food processing.

  1. Wind power plant

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, G

    1975-11-20

    A wind power plant is proposed suitable for electicity generation or water pumping. This plant is to be self-adjusting to various wind velocities and to be kept in operation even during violent storms. For this purpose the mast, carrying the wind rotor and pivotable around a horizontal axis is tiltable and equipped with a wind blind. Further claims contain various configurations of the tilting base resp. the cut in of an elastic link, the attachment and design of the wind blind as well as the constructive arrangement of one or more dynamos.

  2. Power plant process computer

    International Nuclear Information System (INIS)

    Koch, R.

    1982-01-01

    The concept of instrumentation and control in nuclear power plants incorporates the use of process computers for tasks which are on-line in respect to real-time requirements but not closed-loop in respect to closed-loop control. The general scope of tasks is: - alarm annunciation on CRT's - data logging - data recording for post trip reviews and plant behaviour analysis - nuclear data computation - graphic displays. Process computers are used additionally for dedicated tasks such as the aeroball measuring system, the turbine stress evaluator. Further applications are personal dose supervision and access monitoring. (orig.)

  3. Savannah River Plant environment

    International Nuclear Information System (INIS)

    Dukes, E.K.

    1984-03-01

    On June 20, 1972, the Atomic Energy Commission designated 192,323 acres of land near Aiken, SC, as the nation's first National Environmental Research Park. The designated land surrounds the Department of Energy's Savannah River Plant production complex. The site, which borders the Savannah River for 17 miles, includes swampland, pine forests, abandoned town sites, a large man-made lake for cooling water impoundment, fields, streams, and watersheds. This report is a description of the geological, hydrological, meteorological, and biological characteristics of the Savannah River Plant site and is intended as a source of information for those interested in environmental research at the site. 165 references, 68 figures, 52 tables

  4. Quantitative plant ecology

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2014-01-01

    This e-book is written in the Wolfram' CDF format (download free CDF player from Wolfram.com) The objective of this e-book is to introduce the population ecological concepts for measuring and predicting the ecological success of plant species. This will be done by focusing on the measurement...... and statistical modelling of plant species abundance and the relevant ecological processes that control species abundance. The focus on statistical modelling and likelihood function based methods also means that more algorithm based methods, e.g. ordination techniques and boosted regression tress...

  5. PLANTS, SOURCE FOR BIOFUELS

    Directory of Open Access Journals (Sweden)

    Irina Ramona PECINGINĂ

    2016-12-01

    Full Text Available The most affordable alternative energy sources to fossil plants with hydropower are some oils that accumulate in different organs other accumulating carbohydrates with high energy value. They are known worldwide and cultivated a number of plant species entering the oilseeds, which provides significant production of edible oil (soybean, sunflower, etc. Vegetable oils or their product derived biodiesel fuels are potential diesel engines, representing an alternative to fuels. The most promising suitable for the production of oil crops "with short circuit "or biodiesel are fruits and seeds, both herbaceous and tree.

  6. ITER plant systems

    International Nuclear Information System (INIS)

    Kolbasov, B.; Barnes, C.; Blevins, J.

    1991-01-01

    As part of a series of documents published by the IAEA that summarize the results of the Conceptual Design Activities for the ITER project, this publication describes the conceptual design of the ITER plant systems, in particular (i) the heat transport system, (ii) the electrical distribution system, (iii) the requirements for radioactive equipment handling, the hot cell, and waste management, (iv) the supply system for fluids and operational chemicals, (v) the qualitative analyses of failure scenarios and methods of burn stability control and emergency shutdown control, (vi) analyses of tokamak building functions and design requirements, (vii) a plant layout, and (viii) site requirements. Refs, figs and tabs

  7. Fossil power plant automation

    International Nuclear Information System (INIS)

    Divakaruni, S.M.; Touchton, G.

    1991-01-01

    This paper elaborates on issues facing the utilities industry and seeks to address how new computer-based control and automation technologies resulting from recent microprocessor evolution, can improve fossil plant operations and maintenance. This in turn can assist utilities to emerge stronger from the challenges ahead. Many presentations at the first ISA/EPRI co-sponsored conference are targeted towards improving the use of computer and control systems in the fossil and nuclear power plants and we believe this to be the right forum to share our ideas

  8. Plant engineering network

    International Nuclear Information System (INIS)

    Angus, M.J.; Goossen, J.

    1996-01-01

    The Plant Engineering Network (PEN) is a utility-vendor relationship focussed on reducing O and M costs, while maintaining the safe and reliable operation of partner plants through sharing resources, using telecommunications systems for collaborative engineering, coordinating and streamlining work processes, and sharing financial risk and reward. This paper examines how Pacific Gas and Electric (PG and E) established a PEN organization and realized over =0.5 million U.S. in 1994, the first year of implementation, and approximately =2 million U.S. savings in 1995. (author)

  9. Total Logistic Plant Solutions

    Directory of Open Access Journals (Sweden)

    Dusan Dorcak

    2016-02-01

    Full Text Available The Total Logistics Plant Solutions, plant logistics system - TLPS, based on the philosophy of advanced control processes enables complex coordination of business processes and flows and the management and scheduling of production in the appropriate production plans and planning periods. Main attributes of TLPS is to create a comprehensive, multi-level, enterprise logistics information system, with a certain degree of intelligence, which accepts the latest science and research results in the field of production technology and logistics. Logistic model of company understands as a system of mutually transforming flows of materials, energy, information, finance, which is realized by chain activities and operations

  10. Methylome evolution in plants.

    Science.gov (United States)

    Vidalis, Amaryllis; Živković, Daniel; Wardenaar, René; Roquis, David; Tellier, Aurélien; Johannes, Frank

    2016-12-20

    Despite major progress in dissecting the molecular pathways that control DNA methylation patterns in plants, little is known about the mechanisms that shape plant methylomes over evolutionary time. Drawing on recent intra- and interspecific epigenomic studies, we show that methylome evolution over long timescales is largely a byproduct of genomic changes. By contrast, methylome evolution over short timescales appears to be driven mainly by spontaneous epimutational events. We argue that novel methods based on analyses of the methylation site frequency spectrum (mSFS) of natural populations can provide deeper insights into the evolutionary forces that act at each timescale.

  11. Power plants 2009. Lectures

    International Nuclear Information System (INIS)

    2009-01-01

    Within the Annual Conference 2009 of the VGB PowerTech e.V. (Essen, Federal Republic of Germany) from 23rd to 25th May, 2009, in Lyon (France) the following lectures were held: (1) Electricity demand, consequences of the financial and economic crisis - Current overview 2020 for the EU-27 (Hans ten Berge); (2) Status and perspectives of the electricity generation mix in France (Bernard Dupraz); (3) European electricity grid - status and perspective (Dominique Maillard); (4) Technologies and acceptance in the European energy market (Gordon MacKerran); (5) EPR construction in Finland, China, France, (Claude Jaouen); (6) EPR Flamanville 3: A project on the path towards nuclear revival (Jacques Alary); (7) Worldwide nuclear Revival and acceptance (Luc Geraets); (8) An overview on the status of final disposal of radioactive wastes worldwide (Piet Zuidema); (9) Who needs pumped storage plants? PSP are partner to grid stability and renewable energies (Hans-Christoph Funke); (10) Sustainable use of water resources to generate electricity safely and efficiently (Patrick Tourasse); (11) The growth strategy of RWE Innogy - Role of RES in RWE strategy (Fritz Vahrenholt); (12) Solar technologies towards grid parity - key factors and timeframe (G. Gigliucci); (13) Overview on CCS technologies and results of Vattenfalls oxyfuel pilot plant (Philippe Paelinck); (14) Development perspectives of lignite-based IGCC-plants with CCS (Dietmar Keller); (15) Post combustion capture plants - concept and plant integration (Wolfgang Schreier); (16) CCS fossil power generation in a carbon constraint world (Daniel Hofmann); (17) CEZ group strategy in Central and South Eastern Europe (Jan Zizka); (18) Strategy and projects of DONG Energy (Jens Erik Pedersen); (19) E.ON coal-based power generation of the future - The highly efficient power plant and downstream separation of carbon dioxide (Gerhard Seibel); (20) Final sage of first supercritical 460 MW e l. CFB Boiler construction - firs

  12. Wind power plant

    Energy Technology Data Exchange (ETDEWEB)

    Kling, A

    1977-01-13

    The wind power plant described has at least one rotor which is coupled to an electricity generator. The systems are fixed to a suspended body so that it is possible to set up the wind power plant at greater height where one can expect stronger and more uniform winds. The anchoring on the ground or on a floating body is done by mooring cables which can simultaneously have the function of an electric cable. The whole system can be steered by fins. The rotor system itself consists of at least one pair of contrarotating, momentum balanced rotors.

  13. Conceptualizing Pharmaceutical Plants

    DEFF Research Database (Denmark)

    Larsen, Bent Dalgaard; Jensen, Klaes Ladeby; Gjøl, Mikkel

    2006-01-01

    In the conceptual design phase of pharmaceutical plants as much as 80%-90% of the total cost of a project is committed. It is therefore essential that the chosen concept is viable. In this design process configuration and 3D models can help validate the decisions made. Designing 3D models...... is a complex task and requires skilled users. We demonstrate that a simple 2D/3D configuration tool can support conceptualizing of pharmaceutical plants. Present paper reports on preliminary results from a full scale implementation project at a Danish engineering company....

  14. Ardennes nuclear power plant

    International Nuclear Information System (INIS)

    1974-12-01

    The SENA nuclear power plant continued to operate, as before, at authorized rated power, namely 905MWth during the first half year and 950MWth during the second half year. Net energy production:2028GWh; hours phased to the line: 7534H; availability factor: 84%; utilization factor: 84%; total shutdowns:19; number of scrams:10; cost per KWh: 4,35 French centimes. Overall, the plant is performing very satisfactory. Over the last three years net production has been 5900GWh, corresponding to in average utilization factor of 83%

  15. Nuclear power plant

    International Nuclear Information System (INIS)

    Orlov, V.V.; Rineisky, A.A.

    1975-01-01

    The invention is aimed at designing a nuclear power plant with a heat transfer system which permits an accelerated fuel regeneration maintaining relatively high initial steam values and efficiency of the steam power circuit. In case of a plant with three circuits the secondary cooling circuit includes a steam generator with preheater, evaporator, steam superheater and intermediate steam superheater. At the heat supply side the latter is connected with its inlet to the outlet of the evaporator and with its outlet to the low-temperature side of the secondary circuit

  16. Monitoring wood heating plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The overall aim of the project is to support the increased use of biomass heating plant in the UK by improving the quality and quantity of information available to suppliers and users. This aim will be achieved by: providing a qualitative assessment of the operational performance of a representative range of biomass heating installations including summaries of technical information; providing good case studies for a range of installations addressing the varied market demands; collating performance data of existing installations so as to improve the performance and/or reduce capital and operating costs of existing and future installations; and providing basic operator training and recommending methods optimising/improving plant performance. (author)

  17. Apoplastic interactions between plants and plant root intruders

    Directory of Open Access Journals (Sweden)

    Kanako eMitsumasu

    2015-08-01

    Full Text Available Numerous pathogenic or parasitic organisms attack plant roots to obtain nutrients, and the apoplast including the plant cell wall is where the plant cell meets such organisms. Root-parasitic angiosperms and nematodes are two distinct types of plant root parasites but share some common features in their strategies for breaking into plant roots. Striga and Orobanche are obligate root parasitic angiosperms that cause devastating agricultural problems worldwide. Parasitic plants form an invasion organ called a haustorium, where plant cell wall degrading enzymes (PCWDEs are highly expressed. Plant-parasitic nematodes are another type of agriculturally important plant root parasite. These nematodes breach the plant cell walls by protruding a sclerotized stylet from which PCWDEs are secreted. Responding to such parasitic invasion, host plants activate their own defense responses against parasites. Endoparasitic nematodes secrete apoplastic effectors to modulate host immune responses and to facilitate the formation of a feeding site. Apoplastic communication between hosts and parasitic plants also contributes to their interaction. Parasitic plant germination stimulants, strigolactones (SLs, are recently identified apoplastic signals that are transmitted over long distances from biosynthetic sites to functioning sites. Here, we discuss recent advances in understanding the importance of apoplastic signals and cell walls for plant-parasite interactions.

  18. Apoplastic interactions between plants and plant root intruders.

    Science.gov (United States)

    Mitsumasu, Kanako; Seto, Yoshiya; Yoshida, Satoko

    2015-01-01

    Numerous pathogenic or parasitic organisms attack plant roots to obtain nutrients, and the apoplast including the plant cell wall is where the plant cell meets such organisms. Root parasitic angiosperms and nematodes are two distinct types of plant root parasites but share some common features in their strategies for breaking into plant roots. Striga and Orobanche are obligate root parasitic angiosperms that cause devastating agricultural problems worldwide. Parasitic plants form an invasion organ called a haustorium, where plant cell wall degrading enzymes (PCWDEs) are highly expressed. Plant-parasitic nematodes are another type of agriculturally important plant root parasite. These nematodes breach the plant cell walls by protruding a sclerotized stylet from which PCWDEs are secreted. Responding to such parasitic invasion, host plants activate their own defense responses against parasites. Endoparasitic nematodes secrete apoplastic effectors to modulate host immune responses and to facilitate the formation of a feeding site. Apoplastic communication between hosts and parasitic plants also contributes to their interaction. Parasitic plant germination stimulants, strigolactones, are recently identified apoplastic signals that are transmitted over long distances from biosynthetic sites to functioning sites. Here, we discuss recent advances in understanding the importance of apoplastic signals and cell walls for plant-parasite interactions.

  19. B Plant hazards assessment

    International Nuclear Information System (INIS)

    Broz, R.E.

    1994-01-01

    This document establishes the technical basis in support of Emergency Planning Activities for B Plant on the Hanford Site. The document represents an acceptable interpretation of the implementing guidance document for DOE Order 5500.3A. Through this document, the technical basis for the development of facility specific , Emergency Action Levels and the Emergency Planning Zone is demonstrated

  20. Nuclear power plant analyzer

    International Nuclear Information System (INIS)

    Stritar, A.

    1986-01-01

    The development of Nuclear Power Plant Analyzers in USA is described. There are two different types of Analyzers under development in USA, the forst in Idaho and Los Alamos national Lab, the second in brookhaven National lab. That one is described in detail. The computer hardware and the mathematical models of the reactor vessel thermalhydraulics are described. (author)

  1. Plant research '76

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    Overall objective remains unchanged: to contribute to the knowledge, with strong emphasis on fundamental problems, of how plants function, the roles they play in the environment and energy relations of the world, and how these roles may be optimized for the benefit of mankind. (PCS)

  2. Drought Signaling in Plants

    Indian Academy of Sciences (India)

    depending upon the source and nature of signaling: (i) hormone signal, (ii) .... plants to regulate the rate of transpiration through minor structural .... cell has to keep spending energy (in the form of A TP) to maintain a .... enzymes and proteins in the regulation of cellular metabolism can be determined by either inactivating.

  3. Nuclear power plant

    International Nuclear Information System (INIS)

    Wieser, R.

    1979-01-01

    The reactor pressure vessel consists of two parts. A cylindrical lower part with a hemispherical steel roof is placed at some distance within an equally shaped pressure vessel of concrete. Both vessels are standing on a common bottom plate. The interspace is kept at subpressure. It serves to contain ring galleries, elevator shafts, and power plant components. (GL) [de

  4. Recombinant Cytokines from Plants

    Czech Academy of Sciences Publication Activity Database

    Sirko, A.; Vaněk, Tomáš; Gora-Sochacka, A.; Redkiewicz, P.

    2011-01-01

    Roč. 12, č. 6 (2011), s. 3536-3552 ISSN 1661-6596 Institutional research plan: CEZ:AV0Z50380511 Keywords : cytokines * pharmaceutical proteins * plant-based production systems Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.598, year: 2011

  5. Phenolics and Plant Allelopathy

    Directory of Open Access Journals (Sweden)

    De-An Jiang

    2010-12-01

    Full Text Available Phenolic compounds arise from the shikimic and acetic acid (polyketide metabolic pathways in plants. They are but one category of the many secondary metabolites implicated in plant allelopathy. Phenolic allelochemicals have been observed in both natural and managed ecosystems, where they cause a number of ecological and economic problems, such as declines in crop yield due to soil sickness, regeneration failure of natural forests, and replanting problems in orchards. Phenolic allelochemical structures and modes of action are diverse and may offer potential lead compounds for the development of future herbicides or pesticides. This article reviews allelopathic effects, analysis methods, and allelopathic mechanisms underlying the activity of plant phenolic compounds. Additionally, the currently debated topic in plant allelopathy of whether catechin and 8-hydroxyquinoline play an important role in Centaurea maculata and Centaurea diffusa invasion success is discussed. Overall, the main purpose of this review is to highlight the allelopacthic potential of phenolic compounds to provide us with methods to solve various ecology problems, especially in regard to the sustainable development of agriculture, forestry, nature resources and environment conservation.

  6. Plant breeding and genetics

    Science.gov (United States)

    The ultimate goal of plant breeding is to develop improved crops. Improvements can be made in crop productivity, crop processing and marketing, and/or consumer quality. The process of developing an improved cultivar begins with intercrossing lines with high performance for the traits of interest, th...

  7. Plant monitor system

    International Nuclear Information System (INIS)

    Scarola, K.; Jamison, D.; Manazir, R.; Rescori, R.; Harmon, D.

    1991-01-01

    An advanced control room complex for a nuclear power plant, including a discrete indicator and alarm system which is nuclear qualified for rapid response to changes in plant parameters and a component control system which together provide a discrete monitoring and control capability at a panel in the control room. A separate data processing system, which need not be nuclear qualified, provides integrated and overview information to the control room and to each panel, through CRTs and a large, overhead integrated process status overview board. The discrete indicator and alarm system and the data processing system receive inputs from common plant sensors and validate the sensor outputs to arrive at a representative value of the parameter for use by the operator during both normal and accident conditions, thereby avoiding the need for him to assimilate data from each sensor individually. The integrated process status board is at the apex of an information hierarchy that extends through four levels and provides access at each panel to the full display hierarchy. The control room panels are preferably of a modular construction, permitting the definition of inputs and outputs, the main machine interface, and the plant specific algorithms, to proceed in parallel with the fabrication of the panels, the installation of the equipment and the generic testing thereof. (author)

  8. TAPCHAN Wave Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    1983-10-01

    The Tapered Channel Wave Power Plant (TAPCHAN) is based on a new method for wave energy conversion. The principle of operation can be explained by dividing the system into the following four sub-systems: Firstly, a collector which is designed to concentrate the water energy and optimize collection efficiency for a range of frequencies and directions. Secondly, the energy converter, in which the energy of the collected waves is transformed into potential energy in an on-shore water reservoir. This is the unique part of the power plant. It consists of a gradually narrowing channel with wall heights equal to the filling level of the reservoir (typical heights 3-7 m). The waves enter the wide end of the channel and as they propagate down the narrowing channel, the wave height is amplified until the wavecrests spill over the walls. Thirdly, a reservoir which provides a stable water supply for the turbines. Finally, the hydroelectric power plant, where well established techniques are used for the generation of electric power. The water turbine driving the electric generator is of a low head type, such as a Kaplan or a tubular turbine. It must be designed for salt water operation and should have good regulation capabilities. Power plants based on the principle described, are now offered on a commercial basis.

  9. Plant Modernization Programs

    International Nuclear Information System (INIS)

    O'Hara, John

    2004-01-01

    Most nuclear plants were designed and built from the 1960's through the 1990's. These plants employ predominantly analog instrumentation and control (I and C) technology, and their control rooms are made up of primarily hardwired controls (e.g., switches, knobs and handles) and displays (e.g., gauges, linear scales and indicator lights). Over the past several years, these plants have been modernized with digital I and C and computer-based human-system interfaces (HSIs) such as software-based process controls, touch-screen interfaces and large-screen, overview displays. As these computer based HIS technologies are integrated into control rooms based on conventional technology, hybrid control rooms are created. The paper summarizes lessons learned from the study of plant modernization programs over the past ten years so that they can be used to help improve the modification process. While the research focused on the impact of technology change on human performance, a number of organizational and programmatic issues were observed as well. Eleven lessons learned are presented

  10. Plants under continuous light

    NARCIS (Netherlands)

    Velez Ramirez, A.I.; Ieperen, van W.; Vreugdenhill, D.; Millenaar, F.F.

    2011-01-01

    Continuous light is an essential tool for understanding the plant circadian clock. Additionally, continuous light might increase greenhouse food production. However, using continuous light in research and practice has its challenges. For instance, most of the circadian clock-oriented experiments

  11. Nuclear plant scram reduction

    International Nuclear Information System (INIS)

    Wiegle, H.R.

    1986-01-01

    The Nuclear Utility Management and Human Resources Committee (NUMARC) is a confederation of all 55 utilities with nuclear plants either in operation or under construction. NUMARC was formed in April 1984 by senior nuclear executives with hundreds of man-years of plant experience to improve (plant) performance and resolve NRC concerns. NUMARC has adopted 10 commitments in the areas of management, training, staffing and performance. One of these commitments is to strive to reduce automatic trips to 3 per year per unit for calendar year 1985 for plants in commercial operation greater than 3 years (with greater than 25% capacity factor). This goal applies to any unplanned automatic protection system trips at any time when the reactor is critical. Each utility has committed to develop methods to thoroughly evaluate all unplanned automatic trips to identify the root causes and formulate plans to correct the root causes thus reducing future unplanned scrams. As part of this program, the Institute of Nuclear Power Operations (INPO) collects and evaluates information on automatic reactor trips. It publishes the results of these evaluations to aid the industry to identify root causes and corrective actions

  12. Italian steam power plants

    Energy Technology Data Exchange (ETDEWEB)

    von Rautenkranz, J

    1939-01-01

    A brief history of geothermal power production in Italy is presented. Boric acid has been produced on an industrial scale since 1818. The first electrical power was generated in 1904, and by 1939 the output of geothermal power plants had reached 500 GWh, with major expansion of facilities planned.

  13. Plants and Medicinal Chemistry

    Science.gov (United States)

    Bailey, D.

    1977-01-01

    This is the first of two articles showing how plants that have been used in folk medicine for many centuries are guiding scientists in the design and preparation of new and potent drugs. Opium and its chemical derivatives are examined at length in this article. (Author/MA)

  14. Whitebark pine planting guidelines

    Science.gov (United States)

    Ward McCaughey; Glenda L. Scott; Kay L. Izlar

    2009-01-01

    This article incorporates new information into previous whitebark pine guidelines for planting prescriptions. Earlier 2006 guidelines were developed based on review of general literature, research studies, field observations, and standard US Forest Service survival surveys of high-elevation whitebark pine plantations. A recent study of biotic and abiotic factors...

  15. Power plant at sea

    International Nuclear Information System (INIS)

    Roggen, M.

    2000-01-01

    Drilling platforms are rather inefficient when it comes to their own power supply. In view of ecotax and their environmental image, the offshore industry particularly the Norwegians is highly committed to changing this situation. An efficient power plant, specially designed for the offshore industry, might just prove to be the answer to their prayers

  16. Mechanisms in Plant Development

    Energy Technology Data Exchange (ETDEWEB)

    Hake, Sarah [USDA ARS Plant Gene Expression Center

    2013-08-21

    This meeting has been held every other year for the past twenty-two years and is the only regularly held meeting focused specifically on plant development. Topics covered included: patterning in developing tissues; short and long distance signaling; differentiation of cell types; the role of epigenetics in development; evolution; growth.

  17. Plant Biotech Lab Manual.

    Science.gov (United States)

    Tant, Carl

    This book provides laboratory experiments to enhance any food science/botany curriculum. Chapter 1, "Introduction," presents a survey of the techniques used in plant biotechnology laboratory procedures. Chapter 2, "Micronutrition," discusses media and nutritional requirements for tissue culture studies. Chapter 3, "Sterile Seeds," focuses on the…

  18. Radiosensitivity in plants

    International Nuclear Information System (INIS)

    Nauman, A.F.

    1979-01-01

    The report presents a compilation of available data on the sensitivity of plants to ionizing radiation, and provides basic information on methods of determining such sensitivities, or of estimating radiosensitivities by calcuation of the nuclear factors upon which they depend. The scope of the data presented here is necessarily limited to the most generally useful radiobiological end points and to the most commonly-used types of radiation. Many of the factors which influence radiosensitivity, particularly nuclear factors, will be discussed. Emphasis will be upon whole-plant studies done at Brookhaven National Laboratory by A.H. Sparrow and his associates, since these studies are the source of most of the available radiosensitivity data and of all the sensitivity predictions listed here. Data presented here include summaries of experimentally-determined radiosensitivities at various end points for both herbaceous and woody higher plants, and for a few species of ferns and lower plants. The algae and fungi have not been considered here due to space limitations

  19. Chromosome painting in plants.

    NARCIS (Netherlands)

    Schubert, I.; Fransz, P.F.; Fuchs, J.; Jong, de J.H.

    2001-01-01

    The current 'state-of-art' as to chromosome painting in plants is reviewed. We define different situations described as painting so far: i) Genomic in situ hybridisation (GISH) with total genomic DNA to distinguish alien chromosomes on the basis of divergent dispersed repeats, ii) 'Chromosomal in

  20. Nuclear Power Plant Technician

    Science.gov (United States)

    Randall, George A.

    1975-01-01

    The author recognizes a body of basic knowledge in nuclear power plant technoogy that can be taught in school programs, and lists the various courses, aiming to fill the anticipated need for nuclear-trained manpower--persons holding an associate degree in engineering technology. (Author/BP)

  1. Plant cell culture initiation

    NARCIS (Netherlands)

    Hall, R.D.

    2000-01-01

    The use of cultured plant cells in either organized or unorganized form has increased vey considerably in the last 10-15 yr. Many new technologies have been developed and applications in both fundamental and applied research have led to the development of some powerful tools for improving our

  2. Screening for Plant Features

    NARCIS (Netherlands)

    Heijden, van der G.W.A.M.; Polder, G.

    2015-01-01

    In this chapter, an overview of different plant features is given, from (sub)cellular to canopy level. A myriad of methods is available to measure these features using image analysis, and often, multiple methods can be used to measure the same feature. Several criteria are listed for choosing a

  3. The plant exocyst

    NARCIS (Netherlands)

    Zhang, Y.; Emons, A.M.C.; Ketelaar, T.

    2010-01-01

    exocyst is an octameric vesicle tethering complex that functions upstream of SNARE mediated exocytotic vesicle fusion with the plasma membrane. All proteins in the complex have been conserved during evolution, and genes that encode the exocyst subunits are present in the genomes of all plants

  4. Plants flex their skeletons

    DEFF Research Database (Denmark)

    Foster, Randy; Mattsson, Ole; Mundy, John

    2003-01-01

    Recent work on the fragile fiber mutants of Arabidopsis has identified microtubule-associated proteins that affect the orientation of cellulose microfibrils in cell walls, a major determinant of plant elongation growth. These same proteins are implicated in responses to gibberellin, provoking fresh...

  5. Quality maintenance Tropical Plants

    Directory of Open Access Journals (Sweden)

    Gláucia Moraes Dias

    2016-11-01

    Full Text Available The climatic characteristics of the country favor the cultivation of tropical flowers. The continued expansion of this market is due the beauty, exoticit nature and postharvest longevity of flower. However, little is known about the postharvest of tropical plants. Therefore, this paper provides information on harvest, handling and storage of cut tropical plantspostharvest, storage temperature, conditioning solution.

  6. Radiosensitivity in plants

    Energy Technology Data Exchange (ETDEWEB)

    Nauman, A F

    1979-01-01

    The report presents a compilation of available data on the sensitivity of plants to ionizing radiation, and provides basic information on methods of determining such sensitivities, or of estimating radiosensitivities by calcuation of the nuclear factors upon which they depend. The scope of the data presented here is necessarily limited to the most generally useful radiobiological end points and to the most commonly-used types of radiation. Many of the factors which influence radiosensitivity, particularly nuclear factors, will be discussed. Emphasis will be upon whole-plant studies done at Brookhaven National Laboratory by A.H. Sparrow and his associates, since these studies are the source of most of the available radiosensitivity data and of all the sensitivity predictions listed here. Data presented here include summaries of experimentally-determined radiosensitivities at various end points for both herbaceous and woody higher plants, and for a few species of ferns and lower plants. The algae and fungi have not been considered here due to space limitations.

  7. Peru, People and Plants.

    Science.gov (United States)

    Thompson, Dennis

    Designed for horticulture, horticulture therapy, and botany students at Edmonds Community College (Washington), this 6-hour module explores the pre-Columbian use of plant materials in Peru and its relationships to cultural practices in modern Peru. The first sections provide basic information about the module, such as its objectives, the concepts…

  8. Fertilization in Flowering Plants

    Indian Academy of Sciences (India)

    ... for the right pollen,the pistil imposes a tough competition amongst them, comparableto a swayamvara of Indian mythology, to select the bestavailable pollen. Flowering plants have evolved into a matriarchalsociety. The selection of the male partner is totally theprerogative of the mother (pistil); the boy (pollen grain) andthe ...

  9. T Plant hazards assessment

    International Nuclear Information System (INIS)

    Broz, R.E.

    1994-01-01

    This document establishes the technical basis in support of Emergency Planning activities for the T Plant on the Hanford Site. The document represents an acceptable interpretation of the implementing guidance document for DOE ORDER 5500.3A. Through this document, the technical basis for the development of facility specific Emergency Action Levels and the Emergency Planning Zone is demonstrated

  10. Steam power plant

    International Nuclear Information System (INIS)

    Campbell, J.W.E.

    1981-01-01

    This invention relates to power plant forced flow boilers operating with water letdown. The letdown water is arranged to deliver heat to partly expanded steam passing through a steam reheater connected between two stages of the prime mover. (U.K.)

  11. Garigliano nuclear power plant

    International Nuclear Information System (INIS)

    1976-03-01

    During the period under review, the Garigliano power station produced 1,028,77 million kWh with a utilization factor of 73,41% and an availability factor of 85,64%. The disparity between the utilization and availability factors was mainly due to a shutdown of about one and half months owing to lack of staff at the plant. The reasons for nonavailability (14.36%) break down as follows: nuclear reasons 11,49%; conventional reasons 2,81%; other reasons 0,06%. During the period under review, no fuel replacements took place. The plant functioned throughout with a single reactor reticulation pump and resulting maximum available capacity of 150 MWe gross. After the month of August, the plant was operated at levels slightly below the maximum available capacity in order to lengthen the fuel cycle. The total number of outages during the period under review was 11. Since the plant was brought into commercial operation, it has produced 9.226 million kWh

  12. Evolution of plant senescence

    Directory of Open Access Journals (Sweden)

    Young Mike

    2009-07-01

    Full Text Available Abstract Background Senescence is integral to the flowering plant life-cycle. Senescence-like processes occur also in non-angiosperm land plants, algae and photosynthetic prokaryotes. Increasing numbers of genes have been assigned functions in the regulation and execution of angiosperm senescence. At the same time there has been a large expansion in the number and taxonomic spread of plant sequences in the genome databases. The present paper uses these resources to make a study of the evolutionary origins of angiosperm senescence based on a survey of the distribution, across plant and microbial taxa, and expression of senescence-related genes. Results Phylogeny analyses were carried out on protein sequences corresponding to genes with demonstrated functions in angiosperm senescence. They include proteins involved in chlorophyll catabolism and its control, homeoprotein transcription factors, metabolite transporters, enzymes and regulators of carotenoid metabolism and of anthocyanin biosynthesis. Evolutionary timelines for the origins and functions of particular genes were inferred from the taxonomic distribution of sequences homologous to those of angiosperm senescence-related proteins. Turnover of the light energy transduction apparatus is the most ancient element in the senescence syndrome. By contrast, the association of phenylpropanoid metabolism with senescence, and integration of senescence with development and adaptation mediated by transcription factors, are relatively recent innovations of land plants. An extended range of senescence-related genes of Arabidopsis was profiled for coexpression patterns and developmental relationships and revealed a clear carotenoid metabolism grouping, coordinated expression of genes for anthocyanin and flavonoid enzymes and regulators and a cluster pattern of genes for chlorophyll catabolism consistent with functional and evolutionary features of the pathway. Conclusion The expression and phylogenetic

  13. Plant life management optimized utilization of existing nuclear power plants

    International Nuclear Information System (INIS)

    Watzinger, H.; Erve, M.

    1999-01-01

    For safe, reliable and economical nuclear power generation it is of central importance to understand, analyze and manage aging-related phenomena and to apply this information in the systematic utilization and as-necessary extension of the service life of components and systems. An operator's overall approach to aging and plant life management which also improves performance characteristics can help to optimize plant operating economy. In view of the deregulation of the power generation industry with its increased competition, nuclear power plants must today also increasingly provide for or maintain a high level of plant availability and low power generating costs. This is a difficult challenge even for the newest, most modern plants, and as plants age they can only remain competitive if a plant operator adopts a strategic approach which takes into account the various aging-related effects on a plant-wide basis. The significance of aging and plant life management for nuclear power plants becomes apparent when looking at their age: By the year 2000 roughly fifty of the world's 434 commercial nuclear power plants will have been in operation for thirty years or more. According to the International Atomic Energy Agency, as many as 110 plants will have reached the thirty-year service mark by the year 2005. In many countries human society does not push the construction of new nuclear power plants and presumably will not change mind within the next ten years. New construction licenses cannot be expected so that for economical and ecological reasons existing plants have to be operated unchallengeably. On the other hand the deregulation of the power production market is asking just now for analysis of plant life time to operate the plants at a high technical and economical level until new nuclear power plants can be licensed and constructed. (author)

  14. Nuclear power plant safety

    International Nuclear Information System (INIS)

    Otway, H.J.

    1974-01-01

    Action at the international level will assume greater importance as the number of nuclear power plants increases, especially in the more densely populated parts of the world. Predictions of growth made prior to October 1973 [9] indicated that, by 1980, 14% of the electricity would be supplied by nuclear plants and by the year 2000 this figure would be about 50%. This will make the topic of international co-operation and standards of even greater importance. The IAEA has long been active in providing assistance to Member States in the siting design and operation of nuclear reactors. These activities have been pursued through advisory missions, the publication of codes of practice, guide books, technical reports and in arranging meetings to promote information exchange. During the early development of nuclear power, there was no well-established body of experience which would allow formulation of internationally acceptable safety criteria, except in a few special cases. Hence, nuclear power plant safety and reliability matters often received an ad hoc approach which necessarily entailed a lack of consistency in the criteria used and in the levels of safety required. It is clear that the continuation of an ad hoc approach to safety will prove inadequate in the context of a world-wide nuclear power industry, and the international trade which this implies. As in several other fields, the establishment of internationally acceptable safety standards and appropriate guides for use by regulatory bodies, utilities, designers and constructors, is becoming a necessity. The IAEA is presently planning the development of a comprehensive set of basic requirements for nuclear power plant safety, and the associated reliability requirements, which would be internationally acceptable, and could serve as a standard frame of reference for nuclear plant safety and reliability analyses

  15. Photooxidative stress in plants

    International Nuclear Information System (INIS)

    Foyer, C.H.; Lelandais, M.; Kunert, K.J.

    1994-01-01

    The light-dependent generation of active oxygen species is termed photooxidative stress. This can occur in two ways: (1) the donation of energy or electrons directly to oxygen as a result of photosynthetic activity; (2) exposure of tissues to ultraviolet irradiation. The light-dependent destruction of catalase compounds the problem. Although generally detrimental to metabolism, superoxide and hydrogen peroxide may serve useful functions if rigorously controlled and compartmentalised. During photosynthesis the formation of active oxygen species is minimised by a number of complex and refined regulatory mechanisms. When produced, active oxygen species are eliminated rapidly by efficient antioxidative systems. The chloroplast is able to use the production and destruction of hydrogen peroxide to regulate the thermal dissipation of excess excitation energy. This is an intrinsic feature of the regulation of photosynthetic electron transport. Photoinhibition and photooxidation only usually occur when plants are exposed to stress. Active oxygen species are part of the alarm-signalling processes in plants. These serve to modify metabolism and gene expression so that the plant can respond to adverse environmental conditions, invading organisms and ultraviolet irradiation. The capacity of the antioxidative defense system is often increased at such times but if the response is not sufficient, radical production will exceed scavenging and ultimately lead to the disruption of metabolism. Oxidative damage arises in high light principally when the latter is in synergy with additional stress factors such as chilling temperatures or pollution. Environmental stress can modify the photooxidative processes in various ways ranging from direct involvement in light-induced free radical formation to the inhibition of metabolism that renders previously optimal light levels excessive. It is in just such situations that the capacity for the production of active oxygen species can exceed that

  16. Heating plant privatization stagnates

    International Nuclear Information System (INIS)

    Janoska, J.; Benka, M.; Sobinkovic, B.; Haluza, I.

    2005-01-01

    The state has been talking about privatization of 6 municipal heating plants since 2001. The tenders were to start last year. But nothing has happened and the future is uncertain. The city councils would prefer to receive, if not 100%, then at least a majority stake in the heating plants free of charge. But the Cabinet has decided to sell 51% to investors. The privatization agency - the National Property Fund (FNM) is preparing a proposal to increase the stake offered for sale to 67%. According to information provided by the FNM the sale will begin after Cabinet approval. The Fund intends to apply the same model to the sale of all the heating plants. Last year, a major German company Verbundnetz Gas declared its interest in purchasing large municipal heating plants in Slovakia. But it has been waiting for a response ever since. The French company - Dalkia, which has 10-years' experience of doing business in Slovakia, is interested in all the heating plants to be offered for sale. The Austrian company - Stefe is not new to the business either, it is interested mainly in the regions where it has already established itself - Central and Eastern Slovakia. Strategic investors expect financial groups to show interest too. The Penta Group has not hid its ambitions - it has already privatised a company which represents the key to the future development of heat management in Bratislava - Paroplynovy cyklus. Whereas Penta is not new to the heat production business another financial group - Slavia Capital is still surveying the sector. Should it not succeed, it plans several projects that would allow it to take a stake in the sector

  17. Radiochemistry in nuclear power plants

    International Nuclear Information System (INIS)

    Schwarz, W.

    2007-01-01

    Radiochemistry is employed in nuclear power plants not as an end in itself but, among other things, as a main prerequisite of optimum radiation protection. Radiochemical monitoring of various loops provides important information about sources of radioactivity, activity distribution in the plant and its changes. In the light of these analytical findings, plant crews are able to take measures having a positive effect on radiation levels in the plant. The example of a BWR plant is used to show, among other things, how radiochemical analyses helped to reduce radiation levels in a plant and, as a consequence, to decrease clearly radiation exposure of the personnel despite higher workloads. (orig.)

  18. Stainless steels in power plant and plant construction. Papers

    International Nuclear Information System (INIS)

    1994-01-01

    The conference report comprises 14 papers on the corrosion characteristics of stainless steels in power plant and plant engineering. 9 papers are available as separate records in the ENERGY database. (MM) [de

  19. Remediation Using Plants and Plant Enzymes: A Progress Report

    National Research Council Canada - National Science Library

    1995-01-01

    .... In every case, the sources are plants growing near the sediment. The use of plants for remediation of hazardous materials such as TNT or other munitions like RDX and HMX has led to a new approach to remediation-- phytoremediation...

  20. Design of plant safety model in plant enterprise engineering environment

    International Nuclear Information System (INIS)

    Gabbar, Hossam A.; Suzuki, Kazuhiko; Shimada, Yukiyasu

    2001-01-01

    Plant enterprise engineering environment (PEEE) is an approach aiming to manage the plant through its lifecycle. In such environment, safety is considered as the common objective for all activities throughout the plant lifecycle. One approach to achieve plant safety is to embed safety aspects within each function and activity within such environment. One ideal way to enable safety aspects within each automated function is through modeling. This paper proposes a theoretical approach to design plant safety model as integrated with the plant lifecycle model within such environment. Object-oriented modeling approach is used to construct the plant safety model using OO CASE tool on the basis of unified modeling language (UML). Multiple views are defined for plant objects to express static, dynamic, and functional semantics of these objects. Process safety aspects are mapped to each model element and inherited from design to operation stage, as it is naturally embedded within plant's objects. By developing and realizing the plant safety model, safer plant operation can be achieved and plant safety can be assured

  1. Plant responses to plant growth-promoting rhizobacteria

    NARCIS (Netherlands)

    Loon, L.C. van

    2007-01-01

    Non-pathogenic soilborne microorganisms can promote plant growth, as well as suppress diseases. Plant growth promotion is taken to result from improved nutrient acquisition or hormonal stimulation. Disease suppression can occur through microbial antagonism or induction of resistance in the plant.

  2. Plant air systems safety study: Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    1982-05-01

    The Portsmouth Gaseous Diffusion Plant Air System facilities and operations are reviewed for potential safety problems not covered by standard industrial safety procedures. Information is presented under the following section headings: facility and process description (general); air plant equipment; air distribution system; safety systems; accident analysis; plant air system safety overview; and conclusion

  3. Dipping Strawberry Plants in Fungicides before Planting to Control Anthracnose

    Directory of Open Access Journals (Sweden)

    Myeong Hyeon Nam

    2014-03-01

    Full Text Available Anthracnose crown rot (ACR, caused by Colletotrichum fructicola, is a serious disease of strawberry in Korea. The primary inoculums of ACR were symptomless strawberry plants, plant debris, and other host plants. To effectively control anthracnose in symptomless transplanted strawberries, it is necessary to use diseasefree plants, detect the disease early, and apply a fungicide. Therefore, in 2010 and 2011, we evaluated the efficacy of pre-plant fungicide dips by using strawberry transplants infected by C. fructicola for the control of anthracnose. Dipping plants in prochloraz-Mn for 10 min before planting was most effective for controlling anthracnose in symptomless strawberry plants and resulted in more than 76% control efficacy. Azoxystrobin showed a control efficacy of over 40%, but plants treated with pyraclostrobin, mancozeb and iminoctadine tris showed high disease severity. The control efficacy of the dip treatment with prochloraz-Mn did not differ with temperature and time. Treatment with prochloraz-Mn for more than an hour caused growth suppression in strawberry plants. Therefore, the development of anthracnose can be effectively reduced by dipping strawberry plants for 10 min in prochloraz-Mn before planting.

  4. Plant neurobiology and green plant intelligence : science, metaphors and nonsense

    NARCIS (Netherlands)

    Struik, P.C.; Yin, X.; Meinke, H.B.

    2008-01-01

    This paper analyses the recent debates on the emerging science of plant neurobiology, which claims that the individual green plant should be considered as an intelligent organism. Plant neurobiology tries to use elements from animal physiology as elegant metaphors to trigger the imagination in

  5. Nicotinic plant poisoning.

    Science.gov (United States)

    Schep, Leo J; Slaughter, Robin J; Beasley, D Michael G

    2009-09-01

    A wide range of plants contain nicotinic and nicotinic-like alkaloids. Of this diverse group, those that have been reported to cause human poisoning appear to have similar mechanisms of toxicity and presenting patients therefore have comparable toxidromes. This review describes the taxonomy and principal alkaloids of plants that contain nicotinic and nicotinic-like alkaloids, with particular focus on those that are toxic to humans. The toxicokinetics and mechanisms of toxicity of these alkaloids are reviewed and the clinical features and management of poisoning due to these plants are described. This review was compiled by systematically searching OVID MEDLINE and ISI Web of Science. This identified 9,456 papers, excluding duplicates, all of which were screened. Reviewed plants and their principal alkaloids. Plants containing nicotine and nicotine-like alkaloids that have been reported to be poisonous to humans include Conium maculatum, Nicotiana glauca and Nicotiana tabacum, Laburnum anagyroides, and Caulophyllum thalictroides. They contain the toxic alkaloids nicotine, anabasine, cytisine, n-methylcytisine, coniine, n-methylconiine, and gamma-coniceine. These alkaloids act agonistically at nicotinic-type acetylcholine (cholinergic) receptors (nAChRs). The nicotinic-type acetylcholine receptor can vary both in its subunit composition and in its distribution within the body (the central and autonomic nervous systems, the neuromuscular junctions, and the adrenal medulla). Agonistic interaction at these variable sites may explain why the alkaloids have diverse effects depending on the administered dose and duration of exposure. Nicotine and nicotine-like alkaloids are absorbed readily across all routes of exposure and are rapidly and widely distributed, readily traversing the blood-brain barrier and the placenta, and are freely distributed in breast milk. Metabolism occurs predominantly in the liver followed by rapid renal elimination. Following acute exposure

  6. Aquatic Plant Control Research Program

    National Research Council Canada - National Science Library

    Cofrancesco, Alfred

    1998-01-01

    .... This search for natural plant enemies (insects and fungal pathogens) has led researchers to the native ranges of noxious aquatic plants, located throughout the continents of Africa, Asia, Europe, and Australia...

  7. Emission Facilities - Air Emission Plants

    Data.gov (United States)

    NSGIC Education | GIS Inventory — Represents the Primary Facility type Air Emission Plant (AEP) point features. Air Emissions Plant is a DEP primary facility type related to the Air Quality Program....

  8. Mathematical Modelling Plant Signalling Networks

    KAUST Repository

    Muraro, D.; Byrne, H.M.; King, J.R.; Bennett, M.J.

    2013-01-01

    methods for modelling gene and signalling networks and their application in plants. We then describe specific models of hormonal perception and cross-talk in plants. This mathematical analysis of sub-cellular molecular mechanisms paves the way for more

  9. Table showing nutritional plant list

    African Journals Online (AJOL)

    USER

    2013-04-02

    Apr 2, 2013 ... To consider food as medicine is part of a culture and a millennial human ... propagation, and introduction of nutritionally rich, indigenous plant species in the .... some respondents also mentioned that these plants were being ...

  10. Plant status monitor system description

    International Nuclear Information System (INIS)

    Prather, W.A.; Sly, G.A.

    1987-01-01

    In today's regulatory and financial environment, improving plant efficiency and safety are necessary elements of plant operations. Public utility commissions are making rate rulings based, in part, on plant availability performance; and the NRC is putting more emphasis on plant operational aspects. This comes at a time when operating, maintaining, and managing a plant are becoming increasingly complex; moreover, the desired number of experienced plant personnel are becoming more difficult to find. This situation can be partially resolved by using computer software tools to assist operations, maintenance, engineering, and management personnel. These software tools provide information and interpretations based on plant and equipment status. They support improved plant availability, technical specification compliance, and administrative functions. A key element or computerization is the ability to operate on integrated information

  11. Growth, shoot phenology and physiology of diverse seed sources of black spruce: II 23-year-old field trees

    Science.gov (United States)

    Kurt H. Johnsen; John R. Seiler; John E. Major

    1996-01-01

    Four sources of 23-year-old black spruce (Picea mariana (Mill.) B.S.P.) from a provenance test at the Petawawa National Forestry Institute (46° N, 77°30¢ W) were assessed for height growth, shoot phenology and seasonal gas exchange. The provenances were designated 7000 (Yukon, 63°34¢ N, 135°55¢ W), 6979 (Alberta 52°22¢ N, 115°15¢ W), 6908 (Ontario, 48°59¢ N, 80°38¢ W)...

  12. Establishment limitation may be more important than species dispersal: insights from dry grasslands and old-fields

    Czech Academy of Sciences Publication Activity Database

    Knappová, Jana; Hemrová, Lucie; Knapp, M.; Münzbergová, Zuzana

    2017-01-01

    Roč. 28, č. 1 (2017), s. 34-42 ISSN 1100-9233 R&D Projects: GA ČR(CZ) GA15-11635S Institutional support: RVO:67985939 Keywords : distribution * habitat limitation * seed availability Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 2.924, year: 2016

  13. COMPARISON OF THE POPULATIONS OF COMMON WOOD-NYMPH BUTTERFLIES IN BURNED PRAIRIE, UNBURNED PRAIRIE AND OLD FIELD GRASSES

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, M.; Walton, R.

    2007-01-01

    Common wood-nymph butterfl ies are found throughout the United States and Canada. However, not much is known about how they overwinter or their preferences for particular grasses and habitats. In this study, the impact of prairie management plans on the abundance of the wood-nymph population was assessed, as well as the preference of these butterfl ies for areas with native or non-native grasses. The abundance of common wood-nymph butterfl ies was determined using Pollard walks; more common wood-nymph butterfl ies were found in the European grasses than were found in the burned and unburned prairie sites. The majority of the vegetation at each of the three sites was identifi ed and documented. Using a 1 X 3 ANOVA analysis, it was determined there were signifi cantly more butterfl ies in the European grasses than in the burned and unburned prairie sites (p < 0.0005). There was no signifi cant difference between the burned and unburned treatments of the prairie on the common wood-nymph population. A multiple variable linear regression model described the effect of temperature and wind speed on the number of observed common wood-nymph butterfl ies per hour (p = 0.026). These preliminary results need to be supplemented with future studies. Quadrat analysis of the vegetation from all three sites should be done to search for a correlation between common wood-nymph butterfl y abundance per hour and the specifi c types or quantity of vegetation at each site. The effect of vegetation height and density on the observer’s visual fi eld should also be assessed.

  14. Microlensing discovery of a tight, low-mass-ratio planetary-mass object around an old field brown dwarf

    Energy Technology Data Exchange (ETDEWEB)

    Han, C.; Jung, Y. K. [Department of Physics, Chungbuk National University, Cheongju 371-763 (Korea, Republic of); Udalski, A.; Szymański, M. K.; Kubiak, M.; Pietrzyński, G.; Soszyński, I.; Skowron, J.; Kozłowski, S.; Poleski, R.; Ulaczyk, K.; Wyrzykowski, Ł.; Pietrukowicz, P. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Sumi, T. [Department of Earth and Space Science, Osaka University, Osaka 560-0043 (Japan); Gaudi, B. S.; Gould, A. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Bennett, D. P. [University of Notre Dame, Department of Physics, 225 Nieuwland Science Hall, Notre Dame, IN 46556-5670 (United States); Tsapras, Y. [Las Cumbres Observatory Global Telescope Network, 6740B Cortona Dr, Goleta, CA 93117 (United States); Abe, F. [Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya 464-8601 (Japan); Bond, I. A. [Institute of Information and Mathematical Sciences, Massey University, Private Bag 102-904, North Shore Mail Centre, Auckland (New Zealand); Collaboration: OGLE Collaboration; MOA Collaboration; μFUN Collaboration; RoboNet Collaboration; and others

    2013-11-20

    Observations of accretion disks around young brown dwarfs (BDs) have led to the speculation that they may form planetary systems similar to normal stars. While there have been several detections of planetary-mass objects around BDs (2MASS 1207-3932 and 2MASS 0441-2301), these companions have relatively large mass ratios and projected separations, suggesting that they formed in a manner analogous to stellar binaries. We present the discovery of a planetary-mass object orbiting a field BD via gravitational microlensing, OGLE-2012-BLG-0358Lb. The system is a low secondary/primary mass ratio (0.080 ± 0.001), relatively tightly separated (∼0.87 AU) binary composed of a planetary-mass object with 1.9 ± 0.2 Jupiter masses orbiting a BD with a mass 0.022 M {sub ☉}. The relatively small mass ratio and separation suggest that the companion may have formed in a protoplanetary disk around the BD host in a manner analogous to planets.

  15. Fire and nitrogen effects on Purple Threeawn (Aristida purpurea)abundance in northern mixed-grass prairie old fields

    Science.gov (United States)

    Purple threeawn (Aristida purpurea Nutt. varieties) is a native grass capable of increasing on rangelands, forming near monocultures, and creating a stable state. Productive rangelands throughout the Great Plains and Intermountain West have experienced increases in purple threeawn abundance, reduci...

  16. Spontaneous restoration of target vegetation in old-fields in a central European landscape: a repeated analysis after three decades

    Czech Academy of Sciences Publication Activity Database

    Jírová, Alena; Klaudisová, A.; Prach, Karel

    2012-01-01

    Roč. 15, č. 2 (2012), 245-252 ISSN 1402-2001 R&D Projects: GA ČR(CZ) GAP505/11/0256 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : succession * vegetation * abandoned fields Subject RIV: EH - Ecology, Behaviour Impact factor: 2.263, year: 2012

  17. Accommodating for plant modifications

    International Nuclear Information System (INIS)

    Weirich, P.H.

    1977-01-01

    Modification to a nuclear power plant may have different causes: 1) new instructions by the authorities; 2) changes of the marginal conditions on the construction site; 3) progress in the technological development. - Examples from different plants are supposed to demonstrate how such changes influence the planning or the construction and how they are integrated in the process of preparation. A distinction can be made between modifications before the completion of the submission of the order, during the phase of preparatory planning and during the construction phase. Of great importance are especially modifications made after the beginning of the construction works, since, in general, there is little scope for technical modifications and since consequences for the time schedule are to be expected. (orig.) [de

  18. Integrated turbomachine oxygen plant

    Science.gov (United States)

    Anand, Ashok Kumar; DePuy, Richard Anthony; Muthaiah, Veerappan

    2014-06-17

    An integrated turbomachine oxygen plant includes a turbomachine and an air separation unit. One or more compressor pathways flow compressed air from a compressor through one or more of a combustor and a turbine expander to cool the combustor and/or the turbine expander. An air separation unit is operably connected to the one or more compressor pathways and is configured to separate the compressed air into oxygen and oxygen-depleted air. A method of air separation in an integrated turbomachine oxygen plant includes compressing a flow of air in a compressor of a turbomachine. The compressed flow of air is flowed through one or more of a combustor and a turbine expander of the turbomachine to cool the combustor and/or the turbine expander. The compressed flow of air is directed to an air separation unit and is separated into oxygen and oxygen-depleted air.

  19. Nuclear plant license renewal

    International Nuclear Information System (INIS)

    Gazda, P.A.; Bhatt, P.C.

    1991-01-01

    During the next 10 years, nuclear plant license renewal is expected to become a significant issue. Recent Electric Power Research Institute (EPRI) studies have shown license renewal to be technically and economically feasible. Filing an application for license renewal with the Nuclear Regulatory Commission (NRC) entails verifying that the systems, structures, and components essential for safety will continue to perform their safety functions throughout the license renewal period. This paper discusses the current proposed requirements for this verification and the current industry knowledge regarding age-related degradation of structures. Elements of a license renewal program incorporating NRC requirements and industry knowledge including a schedule are presented. Degradation mechanisms for structural components, their significance to nuclear plant structures, and industry-suggested age-related degradation management options are also reviewed

  20. The Chernobyl plant shutdown

    International Nuclear Information System (INIS)

    2000-12-01

    The Chernobylsk-1 reactor, operational in september 1977 has been stopped in november 1996; the Chernobylsk-2 reactor started in november 1978 is out of order since 1991 following a fire. The Chernobylsk-3 reactor began in 1981. During the last three years it occurs several maintenance operations that stop it. In june 2000, the Ukrainian authorities decided to stop it definitively on the 15. of december (2000). This file handles the subject. it is divided in four chapters: the first one gives the general context of the plant shutdown, the second chapter studies the supporting projects to stop definitively the nuclear plant, the third chapter treats the question of the sarcophagus, and the fourth and final chapter studies the consequences of the accident and the contaminated territories. (N.C.)

  1. Power plant simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hacking, D [Marconi Simulation (United Kingdom)

    1992-09-01

    Over many years in the field of simulation Marconi has developed and adopted a number of procedures and methodologies for the management, design and development of an extensive range of training equipment. This equipment encompasses desktop computer-based training systems, generic training devices. The procurement of a training simulator is clearly dictated by the perceived training requirement or problem. Also, it should preferably involve or follow a detailed training needs analysis. Although the cost benefits of training are often difficult to quantify, a simulator is frequently easier to justify if plant familiarisation and training can be provided in advance of on-the-job experience. This is particularly true if the target operators have little hands-on experience of similar plant either in terms of processes or the operator interface. (author).

  2. Radiosensitivity of higher plants

    International Nuclear Information System (INIS)

    Feng Zhijie

    1992-11-01

    The general views on radiosensitivity of higher plants have been introduced from published references. The radiosensitivity varies with species, varieties and organs or tissues. The main factors of determining the radiosensitivity in different species are nucleus volume, chromosome volume, DNA content and endogenous compounds. The self-repair ability of DNA damage and chemical group of biological molecules, such as -SH thiohydroxy of proteins, are main factors to determine the radiosensitivity in different varieties. The moisture, oxygen, temperature radiosensitizer and protector are important external factors for radiosensitivity. Both the multiple target model and Chadwick-Leenhouts model are ideal mathematical models for describing the radiosensitivity of higher plants and the latter has more clear significance in biology

  3. Nuclear power plant

    International Nuclear Information System (INIS)

    Aisaka, Tatsuyoshi; Kamahara, Hisato; Yanagisawa, Ko.

    1982-01-01

    Purpose: To prevent corrosion stress cracks in structural materials in a BWR type nuclear power plant by decreasing the oxygen concentration in the reactor coolants. Constitution: A hydrogen injector is connected between the condensator and a condensate clean up system of a nuclear power plant. The injector is incorporated with hydrogenated compounds formed from metal hydrides, for example, of alloys such as lanthanum-nickel alloy, iron titanium alloy, vanadium, palladium, magnesium-copper alloy, magnesium-nickel alloy and the like. Even if the pressure of hydrogen obtained from a hydrogen bomb or by way of water electrolysis is changed, the hydrogen can always be injected into a reactor coolant at a pressure equal to the equilibrium dissociation pressure for metal hydride by introducing the hydrogen into the hydrogen injector. (Seki, T.)

  4. Mobile power plant units

    Energy Technology Data Exchange (ETDEWEB)

    Radtke, R

    1979-10-05

    Diesel engines of the MaK line 282 AK/332 with a cylinder power up to 160 kW are used, either as 6-cylinder or 8-cylinder in-line engine or as 12-cylinder V engine. Fuel consumption is between 207 and 212 g/kW. The engine is mounted on a frame, together with a generator. The fuel reserve in the tank will last for 8 hours. The lubricating system, the cooling water and starting air system, the switchboard system, and the frame are described. The switchboard plant is mounted either on a skid undercarriage or on the undercarriage. The plant can be operated independently or parallel to the network. The unit can be remote-controlled via push buttons or control knobs. A picture is presented of a mobile diesel aggregate which is in service in Libya.

  5. Dry alcohol production plant

    Directory of Open Access Journals (Sweden)

    Stanković Mirjana S.

    2003-01-01

    Full Text Available The IGPC Engineering Department designed basic projects for dry alcohol production plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects a production plant with a capacity of 40 m3/y was manufactured, at "Zorka Pharma", Šabac in 1995-1996. The product meets all quality demands, as well as environmental regulations. The dry alcohol production process is fully automatized. There is no waste in the process, neither gaseous, nor liquid. The chosen process provides safe operation according to temperature regime and resistance in the pipes, air purification columns and filters. Working at increased pressure is suitable for evaporation and condensation at increased temperatures. The production process can be controlled manually, which is necessary during start-up, and repairs.

  6. Tritium in plants

    International Nuclear Information System (INIS)

    Vichot, L.; Losset, Y.

    2009-01-01

    The presence of tritium in the environment stems from its natural production by cosmic rays, from the fallout of the nuclear weapon tests between 1953 and 1964, and locally from nuclear industry activities. A part of the tritiated water contained in the foliage of plants is turned into organically bound tritium (OBT) by photosynthesis. The tritium of OBT, that is not exchangeable and then piles up in the plant, can be used as a marker of the past. It has been shown that the quantity of OBT contained in the age-rings of an oak that grew near the CEA center of Valduc was directly correlated with the tritium releases of the center. (A.C.)

  7. Third generation nuclear plants

    Science.gov (United States)

    Barré, Bertrand

    2012-05-01

    After the Chernobyl accident, a new generation of Light Water Reactors has been designed and is being built. Third generation nuclear plants are equipped with dedicated systems to insure that if the worst accident were to occur, i.e. total core meltdown, no matter how low the probability of such occurrence, radioactive releases in the environment would be minimal. This article describes the EPR, representative of this "Generation III" and a few of its competitors on the world market.

  8. The intelligent plant

    Energy Technology Data Exchange (ETDEWEB)

    Bruce Firth [CSIRO Energy Technology (Australia)

    2009-06-15

    The current advances in electronics and smart sensors, coupled with the large amount of information that modern distributed control systems can create, provide opportunities but posses some significant problems. The potential suite of data measurements could provide plant operators, maintenance staff and supervisors with a comprehensive understanding of the current health of a coal preparation plant. Analysis of this issue would also provide a tool for the recognition of where important data is not or poorly (timeframe and/or quality) currently available. A suitable system for categorisation of the information associated with the description of the 'Health of a Plant' has been developed. A relational data base model for these categories was derived. The process and performance information relationships were established via the use of models derived from the wide body of literature available. Given the availability of the above model relationships and measurements, the best way to utilise this information in a simple intelligent manner was addressed. It involved the construction of a high level fuzzy set diagnosis chart and an underlying set of unit operation diagnostic charts. These charts provided the basis for the implementation of a generic diagnosis system. This was deliberately developed in EXCEL so that it can be used and/or modified to suit a particular plant. A sensing system which combines a limited set of measurements with an algorithm or logic system for optimisation of a process can be termed a smart sensor. These are vey useful in the optimisation of difficult process situations, and can be used to supplement expert systems. It is believed that the models developed in this project can also provide the basis for appropriate smart sensors when access to appropriate measurements is available.

  9. Nuclear power plant

    International Nuclear Information System (INIS)

    Schabert, H.P.; Laurer, E.

    1976-01-01

    The invention concerns a quick-acting valve on the main-steam pipe of a nuclear power plant. The engineering design of the valve is to be improved. To the main valve disc, a piston-operated auxiliary valve disc is to be assigned closing a section of the area of the main valve disc. This way it is avoided that the drive of the main valve disc has to carry out different movements. 15 sub-claims. (UWI) [de

  10. Fusion power plant economics

    International Nuclear Information System (INIS)

    Miller, R.L.

    1996-01-01

    The rationale, methodology, and updated comparative results of cost projections for magnetic-fusion-energy central-station electric power plants are considered. Changing market and regulatory conditions, particularly in the U.S., prompt fundamental reconsideration of what constitutes a competitive future energy-source technology and has implications for the direction and emphasis of appropriate near-term research and development programs, for fusion and other advanced generation systems. 36 refs., 2 figs., 2 tabs

  11. Parasites, Plants, and People.

    Science.gov (United States)

    Johnson, Marion; Moore, Tony

    2016-06-01

    Anthelminthic resistance is acknowledged worldwide and is a major problem in Aotearoa New Zealand, thus alternative parasite management strategies are imperative. One Health is an initiative linking animal, human, and environmental health. Parasites, plants, and people illustrate the possibilities of providing diverse diets for stock thereby lowering parasite burdens, improving the cultural wellbeing of a local community, and protecting the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Power plant emissions reduction

    Science.gov (United States)

    Anand, Ashok Kumar; Nagarjuna Reddy, Thirumala Reddy

    2015-10-20

    A system for improved emissions performance of a power plant generally includes an exhaust gas recirculation system having an exhaust gas compressor disposed downstream from the combustor, a condensation collection system at least partially disposed upstream from the exhaust gas compressor, and a mixing chamber in fluid communication with the exhaust gas compressor and the condensation collection system, where the mixing chamber is in fluid communication with the combustor.

  13. Automation of solar plants

    Energy Technology Data Exchange (ETDEWEB)

    Yebra, L.J.; Romero, M.; Martinez, D.; Valverde, A. [CIEMAT - Plataforma Solar de Almeria, Tabernas (Spain); Berenguel, M. [Almeria Univ. (Spain). Departamento de Lenguajes y Computacion

    2004-07-01

    This work overviews some of the main activities and research lines that are being carried out within the scope of the specific collaboration agreement between the Plataforma Solar de Almeria-CIEMAT (PSA-CIEMAT) and the Automatic Control, Electronics and Robotics research group of the Universidad de Almeria (TEP197) titled ''Development of control systems and tools for thermosolar plants'' and the projects financed by the MCYT DPI2001-2380-C02-02 and DPI2002-04375-C03. The research is directed by the need of improving the efficiency of the process through which the energy provided by the sun is totally or partially used as energy source, as far as diminishing the costs associated to the operation and maintenance of the installations that use this energy source. The final objective is to develop different automatic control systems and techniques aimed at improving the competitiveness of solar plants. The paper summarizes different objectives and automatic control approaches that are being implemented in different facilities at the PSA-CIEMAT: central receiver systems and solar furnace. For each one of these facilities, a systematic procedure is being followed, composed of several steps: (i) development of dynamic models using the newest modeling technologies (both for simulation and control purposes), (ii) development of fully automated data acquisition and control systems including software tools facilitating the analysis of data and the application of knowledge to the controlled plants and (iii) synthesis of advanced controllers using techniques successfully used in the process industry and development of new and optimized control algorithms for solar plants. These aspects are summarized in this work. (orig.)

  14. Antibodies from plants for bionanomaterials

    OpenAIRE

    Edgue, G.; Twyman, R.M.; Beiss, V.; Fischer, R.; Sack, M.

    2017-01-01

    Antibodies are produced as part of the vertebrate adaptive immune response and are not naturally made by plants. However, antibody DNA sequences can be introduced into plants, and together with laboratory technologies that allow the design of antibodies recognizing any conceivable molecular structure, plants can be used as green factories' to produce any antibody at all. The advent of plant-based transient expression systems in particular allows the rapid, convenient, and safe production of a...

  15. Plant Pathogenicity in Spaceflight Environments

    OpenAIRE

    Bishop, Deborah L.; Levine, Howard G.; Anderson, Anne J.

    1996-01-01

    Plants grown in microgravity are subject to many environmental stresses, which may promote microbial growth and result in pathogenicity to the plant. Recent plant experiments with super dwarf wheat aboard the NASA Space Shuttle and NASA/Russian Mir Space Station returned from the mission with severe degrees of fungal contamination. Understanding the cause of such microbial contamination and methods to eliminate it are necessary prerequisites for continued plant growth and development studies ...

  16. On nuclear power plant uprating

    International Nuclear Information System (INIS)

    Ho, S. Allen; Bailey, James V.; Maginnis, Stephen T.

    2004-01-01

    Power uprating for commercial nuclear power plants has become increasingly attractive because of pragmatic reasons. It provides quick return on investment and competitive financial benefits, while involving low risks regarding plant safety and public objection. This paper briefly discussed nuclear plant uprating guidelines, scope for design basis analysis and engineering evaluation, and presented the Salem nuclear power plant uprating study for illustration purposes. A cost and benefit evaluation of the Salem power uprating was also included. (author)

  17. From plant genomes to phenotypes

    OpenAIRE

    Bolger, Marie; Gundlach, Heidrun; Scholz, Uwe; Mayer, Klaus; Usadel, Björn; Schwacke, Rainer; Schmutzer, Thomas; Chen, Jinbo; Arend, Daniel; Oppermann, Markus; Weise, Stephan; Lange, Matthias; Fiorani, Fabio; Spannagl, Manuel

    2017-01-01

    Recent advances in sequencing technologies have greatly accelerated the rate of plant genome and applied breeding research. Despite this advancing trend, plant genomes continue to present numerous difficulties to the standard tools and pipelines not only for genome assembly but also gene annotation and downstream analysis.Here we give a perspective on tools, resources and services necessary to assemble and analyze plant genomes and link them to plant phenotypes.

  18. Deep Learning for Plant Phenotyping

    OpenAIRE

    Mori, Matteo

    2016-01-01

    Plant Phenotyping is an emerging science which provides us the knowledge to better understand plants. Indeed, the study of the link between genetic background and environment in which plants develop can help us to determine cures for plants’ sicknesses and new ways to improve yields using limited resources. In this regard, one of the main aspects of Plant Phenotyping that were studied in the past, was Root Phenotyping, which is based on the study of the root architectures. In particular, toda...

  19. Process Experimental Pilot Plant

    International Nuclear Information System (INIS)

    Henze, H.

    1986-01-01

    The Process Experimental Pilot Plant (PREPP) at the Idaho National Engineering Laboratory (INEL) was built to convert transuranic contaminated solid waste into a form acceptable for disposal at the Waste Isolation Pilot Plant (WIPP), located near Carlsbad, New Mexico. There are about 2.0 million cubic ft of transuranic waste stored at the Transuranic Storage Area of the INEL's Radioactive Waste Management Complex (RWMC). The Stored Waste Examination Pilot Plant (SWEPP) located at the RWMC will examine this stored transuranic waste to determine if the waste is acceptable for direct shipment to and storage at WIPP, or if it requires shipment to PREPP for processing before shipment to WIPP. The PREPP process shreds the waste, incinerates the shredded waste, and cements (grouts) the shredded incinerated waste in new 55-gal drums. Unshreddable items are repackaged and returned to SWEPP. The process off-gas is cleaned prior to its discharge to the atmosphere, and complies with the effluent standards of the State of Idaho, EPA, and DOE. Waste liquid generated is used in the grouting operation

  20. Waste incinerating plant

    Energy Technology Data Exchange (ETDEWEB)

    1972-12-01

    This plant is provided with a NKK-Ferunst type reciprocating stage fire lattice which has a good ventilating effect and a proper stirring and loosening effect, achieving a high combustion rate, and has also a gas flow system by which gas can flow in the reverse direction to adjust its flow for seasonal variations in the quality of waste. Also, a room in which the exhaust gas is mixed is provided in this plant as a help for the complete neutralization and combustion of acid gas such as hydrogen chloride and imperfect combustion gas from plastic waste contained in wastes. In this system, waste can accept a sufficient radiant heat from the combustion gas, the furnace wall, and the ceiling; even on the post combustion fire lattice the ashes are given heat enough to complete the post combustion, so that it can be completely reduced to ashes. For these reasons, this type of incinerator is suitable for the combustion of low-calorie wastes such as city wastes. The harmful gases resulting from the combustion of wastes are treated completely by desulfurization equipment which can remove the oxides of sulfur. This type of plant also can dispose of a wide variety of wastes, and is available in several capacities from 30 tons per 8 hr to 1,200 tons per 24 hr.

  1. Genetics and plant development.

    Science.gov (United States)

    Prunet, Nathanaël; Meyerowitz, Elliot M

    2016-01-01

    There are only three grand theories in biology: the theory of the cell, the theory of the gene, and the theory of evolution. Two of these, the cell and gene theories, originated in the study of plants, with the third resulting in part from botanical considerations as well. Mendel's elucidation of the rules of inheritance was a result of his experiments on peas. The rediscovery of Mendel's work in 1900 was by the botanists de Vries, Correns, and Tschermak. It was only in subsequent years that animals were also shown to have segregation of genetic elements in the exact same manner as had been shown in plants. The story of developmental biology is different - while the development of plants has long been studied, the experimental and genetic approaches to developmental mechanism were developed via experiments on animals, and the importance of genes in development (e.g., Waddington, 1940) and their use for understanding developmental mechanisms came to botanical science much later - as late as the 1980s. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  2. Beloyarsk Nuclear Power Plant

    International Nuclear Information System (INIS)

    1997-01-01

    The Beloyarsk Nuclear Power Plant (BNPP) is located in Zarechny, approximately 60 km east of Ekaterinberg along the Trans-Siberian Highway. Zarechny, a small city of approximately 30,000 residents, was built to support BNPP operations. It is a closed city to unescorted visitors. Residents must show identification for entry. BNPP is one of the first and oldest commercial nuclear power plants in Russia and began operations in 1964. As for most nuclear power plants in the Russian Federation, BNPP is operated by Rosenergoatom, which is subordinated to the Ministry of Atomic Energy of the Russian Federation (Minatom). BNPP is the site of three nuclear reactors, Units 1, 2, and 3. Units 1 and 2, which have been shut-down and defueled, were graphite moderated reactors. The units were shut-down in 1981 and 1989. Unit 3, a BN-600 reactor, is a 600 MW(electric) sodium-cooled fast breeder reactor. Unit 3 went on-line in April 1980 and produces electric power which is fed into a distribution grid and thermal power which provides heat to Zarechny. The paper also discusses the SF NIKIET, the Sverdiovsk Branch of NIKIET, Moscow, which is the research and development branch of the parent NIKEIT and is primarily a design institute responsible for reactor design. Central to its operations is a 15 megawatt IVV research reactor. The paper discusses general security and fissile material control and accountability at these two facilities

  3. Profitability of irradiation plants

    International Nuclear Information System (INIS)

    Bustos R, M.E.; Gonzalez F, C.; Liceaga C, G.; Ortiz A, G.

    1997-01-01

    In any industrial process it is seek an attractive profit from the contractor and the social points of view. The use of the irradiation technology in foods allows keep their hygienically, which aid to food supply without risks for health, an increment of new markets and a losses reduction. In other products -cosmetics or disposable for medical use- which are sterilized by irradiation, this process allows their secure use by the consumers. The investment cost of an irradiation plant depends mainly of the plant size and the radioactive material reload that principally is Cobalt 60, these two parameters are in function of the type of products for irradiation and the selected doses. In this work it is presented the economic calculus and the financial costs for different products and capacities of plants. In general terms is determined an adequate utility that indicates that this process is profitable. According to the economic and commercial conditions in the country were considered two types of credits for the financing of this projects. One utilizing International credit resources and other with national sources. (Author)

  4. Communal biomass conversion plants

    International Nuclear Information System (INIS)

    1991-06-01

    The Coordinating Committee set up by the Danish government in 1986 were given the responsibility of investigating the potentials for biomass conversion plants in Denmark, especially in relation to agricultural, environmental and energy aspects. The results of the Committee's plan of management for this project are presented. This main report covers 13 background reports which deal with special aspects in detail. The report describes the overall plan of management, the demonstration and follow-up programme and the individual biogas demonstration plants. Information gained from these investigations is presented. The current general status, (with emphasis on the technical and economical aspects) and the prospects for the future are discussed. The interest other countries have shown in Danish activities within the field of biogas production is described, and the possibilities for Danish export of technology and know-how in this relation are discussed. It is claimed that Denmark is the first country that has instigated a coordinated development programme for biomass conversion plants. (AB) 24 refs

  5. Regulating nutrient allocation in plants

    Science.gov (United States)

    Udvardi, Michael; Yang, Jiading; Worley, Eric

    2014-12-09

    The invention provides coding and promoter sequences for a VS-1 and AP-2 gene, which affects the developmental process of senescence in plants. Vectors, transgenic plants, seeds, and host cells comprising heterologous VS-1 and AP-2 genes are also provided. Additionally provided are methods of altering nutrient allocation and composition in a plant using the VS-1 and AP-2 genes.

  6. Try This: Plant Leaf Exploration

    Science.gov (United States)

    Preston, Christine

    2017-01-01

    Plants are often overlooked in favour of animals when teaching about living things. Focusing on familiar animals that share human characteristics helps young children learn about similar features. Examining plants for their differences, though, helps foster wonder. In the author's experience, children find it intriguing that plants need…

  7. Global Activities and Plant Survival

    DEFF Research Database (Denmark)

    Bandick, Roger

    2014-01-01

    the highest exit rates. Moreover, the exit rates of globally engaged plants seem to be unaffected by increased foreign presence, whereas there appears to be a negative impact on the survival rates of non-exporting non-MNE plants. Finally, the result reveals that the survival ratio of plants of acquired...

  8. PERSPECTIVE IN PLANT DRUG RESEARCH

    Science.gov (United States)

    Singh, R.H.; Singh, K.P.

    1990-01-01

    Plant medicine becomes more popular thought the world in these days probably of its latest toxicity. Ayurveda that leads in plant medicine preserves the natural form of herbs maximum, in various pharmaceutical preparations. Isolation of active principles has not proved much fruitful. However, the need of hour is cultivation of more medicinal plants along with popularization of their use traditional simpler forms. PMID:22557691

  9. Selected Landscape Plants. Slide Script.

    Science.gov (United States)

    McCann, Kevin

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with commercially important woody ornamental landscape plants. Included in the script are narrations for use with a total of 253 slides illustrating 92 different plants. Several slides are used to illustrate each plant: besides a view of…

  10. Gamma irradiation plants using reactor fuel elements

    International Nuclear Information System (INIS)

    Suckow, W.

    1976-11-01

    Recent irradiation plants utilizing fuel elements are described. Criteria for optimizing such plants, evaluation of the plants realized so far, and applications for the facilities are discussed. (author)

  11. Four planting devices for planting no-till maize

    Directory of Open Access Journals (Sweden)

    Osei Bonsu Patterson

    2015-05-01

    Full Text Available An experiment was conducted at the CSIR-Crops Research Institute (CSIR-CRI Experimental station at Ejura in Ghana to compare the efficiency of four devices for planting no-till maize: Tractor drawn seeder, Chinese made jab planter, Locally made jab planter and a Cutlass. It took two (2 hours 48 minutes to plant one hectare of maize with the tractor drawn seeder, which was significantly (p less than 1% faster than all the planting methods. Cutlass was the slowest planting device lasting more than 14 hours per hectare. There was no significant difference in planting time between the Chinese planter and local planter. Economic analysis showed that cutlass planting produced the highest net benefit, whilst tractor drawn seeder produced the least benefit. In this study cutlass planting was done with precision by collaborating farmers. In actual farm situation however, hired laborers (planting gangs often plant in haste which often results in poor plant population leading to low yields. Tractor drawn seeders or jab planters could reduce drudgery in planting and encourage farm expansion.

  12. Regulatory requirements for desalination plant coupled with nuclear reactor plant

    International Nuclear Information System (INIS)

    Yune, Young Gill; Kim, Woong Sik; Jo, Jong Chull; Kim, Hho Jung; Song, Jae Myung

    2005-01-01

    A small-to-medium sized reactor has been developed for multi-purposes such as seawater desalination, ship propulsion, and district heating since early 1990s in Korea. Now, the construction of its scaled-down research reactor, equipped with a seawater desalination plant, is planned to demonstrate the safety and performance of the design of the multi-purpose reactor. And the licensing application of the research reactor is expected in the near future. Therefore, a development of regulatory requirements/guides for a desalination plant coupled with a nuclear reactor plant is necessary for the preparation of the forthcoming licensing review of the research reactor. In this paper, the following contents are presented: the design of the desalination plant, domestic and foreign regulatory requirements relevant to desalination plants, and a draft of regulatory requirements/guides for a desalination plant coupled with a nuclear reactor plant

  13. Arabinogalactan proteins in plants

    Directory of Open Access Journals (Sweden)

    Ewa Szczuka

    2013-04-01

    Full Text Available AGPs (arabinogalactan-proteins are the major constituent of arabic gum and have been used as emulsifiers and stabilizing agents. They are also one of the most abundant and heterogeneous class forming a large family of proteoglycans that sculpt the surface not only of plant but also of all eukaryotic cells. Undoubtedly, AGPs appear in numerous biological processes, playing diverse functions. Despite their abundance in nature and industrial utility, the in vivofunction(s of AGPs still remains unclear or even unknown. AGPs are commonly distributed in different plant organs and probably participate in all aspects of plant growth and development including reproduction (e.g. they are present in the stigma including stigma exudates, and in transmitting tissues in styles, pollen grains, and pollen tubes. The functions and evident involvement of AGPs in sexual plant reproduction in a few plant species as Actinidia deliciosa (A.Chev. C.F.Liang & A.R.Ferguson, Amaranthus hypochondriacus L., Catharanthus roseus (L. G.Don, Lolium perenneL. and Larix deciduaMill. are known from literature. The localization of two kinds of AGP epitopes, recognized by the JIM8 and JIM13 mAbs, in anatomically different ovules revealed some differences in spatial localization of these epitopes in ovules of monocots Galanthus nivalis L. and Galtonia candicans (Baker Decne. and dicots like Oenothera species and Sinapis albaL. A detailed study of the localization of AGPs in egg cells, zygotes, including the zygote division stage, and in two-celled proembryos in Nicotiana tabacumL. prompts consideration of the necessity of their presence in the very early steps of ontogenesis. The selective labeling obtained with AGP mAbs JIM8, JIM13, MAC207, and LM2 during Arabidopsis thaliana(L. Heynh. development suggests that some AGPs can be regarded as molecular markers for gametophytic cell differentiation. Moreover, the results show evident differences in the distribution of specific AGP

  14. Plant ecdysteroids: plant sterols with intriguing distributions, biological effects and relations to plant hormones.

    Science.gov (United States)

    Tarkowská, Danuše; Strnad, Miroslav

    2016-09-01

    The present review summarises current knowledge of phytoecdysteroids' biosynthesis, distribution within plants, biological importance and relations to plant hormones. Plant ecdysteroids (phytoecdysteroids) are natural polyhydroxylated compounds that have a four-ringed skeleton, usually composed of either 27 carbon atoms or 28-29 carbon atoms (biosynthetically derived from cholesterol or other plant sterols, respectively). Their physiological roles in plants have not yet been confirmed and their occurrence is not universal. Nevertheless, they are present at high concentrations in various plant species, including commonly consumed vegetables, and have a broad spectrum of pharmacological and medicinal properties in mammals, including hepatoprotective and hypoglycaemic effects, and anabolic effects on skeletal muscle, without androgenic side-effects. Furthermore, phytoecdysteroids can enhance stress resistance by promoting vitality and enhancing physical performance; thus, they are considered adaptogens. This review summarises current knowledge of phytoecdysteroids' biosynthesis, distribution within plants, biological importance and relations to plant hormones.

  15. Beaver herbivory on aquatic plants.

    Science.gov (United States)

    Parker, John D; Caudill, Christopher C; Hay, Mark E

    2007-04-01

    Herbivores have strong impacts on marine and terrestrial plant communities, but their impact is less well studied in benthic freshwater systems. For example, North American beavers (Castor canadensis) eat both woody and non-woody plants and focus almost exclusively on the latter in summer months, yet their impacts on non-woody plants are generally attributed to ecosystem engineering rather than herbivory. Here, we excluded beavers from areas of two beaver wetlands for over 2 years and demonstrated that beaver herbivory reduced aquatic plant biomass by 60%, plant litter by 75%, and dramatically shifted plant species composition. The perennial forb lizard's tail (Saururus cernuus) comprised less than 5% of plant biomass in areas open to beaver grazing but greater than 50% of plant biomass in beaver exclusions. This shift was likely due to direct herbivory, as beavers preferentially consumed lizard's tail over other plants in a field feeding assay. Beaver herbivory also reduced the abundance of the invasive aquatic plant Myriophyllum aquaticum by nearly 90%, consistent with recent evidence that native generalist herbivores provide biotic resistance against exotic plant invasions. Beaver herbivory also had indirect effects on plant interactions in this community. The palatable plant lizard's tail was 3 times more frequent and 10 times more abundant inside woolgrass (Scirpus cyperinus) tussocks than in spatially paired locations lacking tussocks. When the protective foliage of the woolgrass was removed without exclusion cages, beavers consumed nearly half of the lizard's tail leaves within 2 weeks. In contrast, leaf abundance increased by 73-93% in the treatments retaining woolgrass or protected by a cage. Thus, woolgrass tussocks were as effective as cages at excluding beaver foraging and provided lizard's tail plants an associational refuge from beaver herbivory. These results suggest that beaver herbivory has strong direct and indirect impacts on populations and

  16. Autophagy in plant pathogenic fungi.

    Science.gov (United States)

    Liu, Xiao-Hong; Xu, Fei; Snyder, John Hugh; Shi, Huan-Bin; Lu, Jian-Ping; Lin, Fu-Cheng

    2016-09-01

    Autophagy is a conserved cellular process that degrades cytoplasmic constituents in vacuoles. Plant pathogenic fungi develop special infection structures and/or secrete a range of enzymes to invade their plant hosts. It has been demonstrated that monitoring autophagy processes can be extremely useful in visualizing the sequence of events leading to pathogenicity of plant pathogenic fungi. In this review, we introduce the molecular mechanisms involved in autophagy. In addition, we explore the relationship between autophagy and pathogenicity in plant pathogenic fungi. Finally, we discuss the various experimental strategies available for use in the study of autophagy in plant pathogenic fungi. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. B plant mission analysis report

    International Nuclear Information System (INIS)

    Lund, D.P.

    1995-01-01

    This report further develops the mission for B Plant originally defined in WHC-EP-0722, ''System Engineering Functions and Requirements for the Hanford Cleanup Mission: First Issue.'' The B Plant mission analysis will be the basis for a functional analysis that breaks down the B Plant mission statement into the necessary activities to accomplish the mission. These activities are the product of the functional analysis and will then be used in subsequent steps of the systems engineering process, such as identifying requirements and allocating those requirements to B Plant functions. The information in this mission analysis and the functional and requirements analysis are a part of the B Plant technical baseline

  18. The plants in the Florilegia

    DEFF Research Database (Denmark)

    Arnklit, Folmer; Frederiksen, Signe; Hansen, Hans Vilhelm

    2013-01-01

    The Gottorfer Codex and The Green Florilegium contain a total of more than 1,500 pictures of plants. In this article the botanists who recently identified the plants in the two albums take a look at the works as seen through the eyes of a botanist. Based on their knowledge of the plants behind...... the pictures the authors shed light on a range of different aspects, e.g. the relationship between figures and real plants and the horticultural background of the plants. They also offer botanical explanations for peculiarities such as double and proliferous flowers....

  19. Towards Multi Fuel SOFC Plant

    DEFF Research Database (Denmark)

    Rokni, Masoud; Clausen, Lasse Røngaard; Bang-Møller, Christian

    2011-01-01

    Complete Solid Oxide Fuel Cell (SOFC) plants fed by several different fuels are suggested and analyzed. The plants sizes are about 10 kW which is suitable for single family house with needs for both electricity and heat. Alternative fuels such as, methanol, DME (Di-Methyl Ether) and ethanol...... are also considered and the results will be compared with the base plant fed by Natural Gas (NG). A single plant design will be suggested that can be fed with methanol, DME and ethanol whenever these fuels are available. It will be shown that the plant fed by ethanol will have slightly higher electrical...

  20. Aquatic Plant Control Research Program. Allelopathic Aquatic Plants for Aquatic Plant Management: A Feasibility Study

    Science.gov (United States)

    1989-10-01

    1978. " Ecotoxicology of aquatic plant communi- ties," Principles of Ecotoxicology , SCOPE Report 12, Chapter 11, pp 239-255. [Heavy metals, Pollutants...Phragmites communis and Equisetum limosum were cultivated . They found plant-plant influences depend on soil type. Typha latifolia, S. A2 lacustris, and